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Supervillainy: Astroengineering Global Warming

By Russell Dovey in Op-Ed
Fri Apr 08, 2005 at 03:03:17 AM EST
Tags: Science (all tags)
Science

Last year in April, at a sf convention here in Canberra, I watched a presentation on global warming by Gregory Benford, supposedly telling us about a global warming summit that he had recently participated in. Anticipating the nature of his audience, he first showed us the summit's deliberately conservative final numbers on temperature rise, carbon dioxide levels etc for the next 26 years, then quickly demolished some popular but flawed solutions with clear logic and straightforward calculation.


Then he showed us the solution that he'd presented, amid mixed amusement and excitement, to the distinguished climatologists, meteorologists, physicists, chemists, biologists, political scientists, economists, engineerists, environmentalists and journalists at the summit.

As a result of attending Greg's little overhead-projected show, I now believe that the cheapest, most effective and most practical answer to global warming is to think like a supervillain and block out the sun's rays using a giant rotating Space Lens suspended directly in front of the Sun! Muahahaha!

Let me tell you why.


Gregory Benford is a professor of plasma physics and astrophysics at the University of California, and received his PhD in 1967. He's been an adviser for NASA, the Department of Energy and the White House Council on Space Policy, and attended the first NSF global warming summit back in 1992. He's also a writer, and has bashed out some of the best hard sci-fi novels of the modern age, including Timescape, Cosm, and the Galactic Center Saga which spanned six books from In The Ocean Of Night to Sailing Bright Eternity.

This experience of painting mind-expanding mental images with strict scientific accuracy allowed him to give a very complete picture of the challenges of global warming, free of the usual distortions, half-remembered statistics and lies motivated by personal gain.

Using the "best case" global warming numbers agreed on by the summit to destroy one solution popular among the ignorant, he showed that for nuclear power to make enough of a difference to stop global warming by 2030, the world would have to replace the electrical output of one large coal-fired power station with an equivalent nuclear power station, EVERY DAY for the next 25 years. Every damn day. 365 per year. I would not have believed the figures if I hadn't seen every step of his working-out in that meeting.

Stopping global warming by 2030 is vital because it is a tipping-point where the rising temperatures begin to trigger the release of carbon dioxide and methane from natural sources, which raise temperatures, which release more carbon etc; in other words, after the expected temperature rise by 2030, we will experience a runaway greenhouse effect resulting in huge increases of eight degrees Celsius or more by 2100.

The effect of an eight degree rise in global temperatures would be catastrophic. One effect would be rising seas flooding the land upon which around half the world's population currently lives. Another would be the destruction of biodiversity on a scale dwarfing even our current extinction rate, as entire populations desperately flee to remote areas, rising seas drown whole ecosystems, and habitats disappear due to the climate shift.

In any case, it is clearly impossible for us to stop global warming solely by replacing our current and future power generation with nuclear power. Quite apart from the expense of building a new nuclear power station every day for 25 years, there is not enough nuclear fuel on the planet to cope with the demand. We must think of other ways, such as solar, wind, geothermal or tidal power, architectural albedo modification (Painting roofs and roads white, since white will reflect sunlight more effectively and increase Earth's reflectivity), geoengineering (from filling the stratosphere with silver foil to burying carbon dioxide in the ocean) and lifestyle changes.

However, if we're realistic, the governments of the world will never be up to the huge plethora of detail this multifaceted solution would entail. I personally think that Gregory Benford's plan, which he presented to the summit and showed us in the talk, is the best (cheapest, most practical and most effective) option we've currently got available. It is also the most fun, though an atmosphere full of floating silver foil might be a close second until planes start flying through air-drifts of foil and their engines explode.

Dr Benford, while doing most of the work himself, has exploited his friends at NASA to confirm that the engineering is viable, and the results were astounding: The whole project could be achieved with today's technology at a cost of $10 billion US dollars up-front, and another ten for maintenance over the decades of designed lifespan.

That's a lot of money, but it's still about two-fifths of the initial appropriation from Congress for the Iraq war. Benford proposes an international collaboration between wealthy nations to spread the load, and I would also suggest commercial sponsors. This would make the project almost indecently viable, considering the return each nation would get from being able to ignore Kyoto and its successors for as long as they feel like.

Gregory Benford's idea is to build a concave Fresnel Lens 1000 kilometres across but only a few millimetres thick at the L1 stable orbital point between us and the Sun, to slightly diffuse its light and cool us down enough to balance the warming effect of carbon dioxide, methane etc.

A few explanations are in order for that sentence:


  • The L1 (Lagrange 1) point is a point in space on a direct line between the Earth and the sun, 1.5 million kilometres away from our little blue dot. At that point, the gravity of the Earth is balanced with that of the Sun in such a way that anything placed there will, if gently nudged back into place every 25 days or so, orbit the Sun once every year. This means that it will remain directly between Earth and Sun with almost no fuel expenditure. Currently there's a solar observatory satellite called SOHO there. It may have to move.


  • A Fresnel lens is simply a magnifying (convex, outward curving) or diffusing (concave, inward curving) glass, with all the useless inside glass taken out and the lens concentrically cut into thousands of ringlike sections. If you've seen a lighthouse's light up close, or one of those flat sheets of plastic that nevertheless magnifies things, you've seen a convex Fresnel lens.


  • Dr Benford's circular, millimetres-thin Lens would be made from an advanced plastic, and would need to be adjustable to fine-tune the amount of light that it prevented from reaching the Earth. Benford proposes spinning the 1000-kilometre structure fast enough to stiffen and maintain its shape. The Lens would need thrusters around its rim to keep from drifting away, and these may also assist the focussing and spinup stages.




The reduction in incoming sunlight would be 0.5 to 1%, enough to neatly stop global warming and keep temperatures stable. It would give us time to stabilise our emissions, then start the long process of filtering greenhouse gases back out of the atmosphere and storing them somewhere. The Lens can of course be adjusted, so as greenhouse gas levels dropped the diffusion effect would be reduced as well, until we reached a point where the Lens was no longer required and could be safely dismantled, or more playfully used to frighten the hell out of everyone in a medium-sized nation with an appropriate orbital insertion to enter the Earth's atmosphere flat-on.

The downside of this approach is that the other effects of the increased carbon dioxide would have to be addressed, such as increased plant growth (great if you like weeds) and less of an incentive not to pollute the air with fossil fuels. Coal might seem like an even better option to fast-growing developing countries like China, Brazil and Nigeria, meaning sooty, gritty misery for anyone living nearby, unless stringent pollution standards are internationally enforced somehow.

More info on the L1 point and Gregory Benford can be reached on Google, while the continuing progress of the 1-kilometre high, no-emission, oxygen-producing, 200-megawatt Australian solar tower which will be built by 2009 at Buronga, 25 ks east of Mildura in New South Wales, can be found here. The project has just recently purchased the land they plan to build upon, and has so far defied the usual predictions of failure that accompany any new way of doing things. Here's hoping that the Solar Tower is successful, just so some madman decides to build a 2-kilometre high one to show up those damn Aussies.

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Poll
Favourite villainous climate stabilisation device?
o Gregory Benford's Rotating Space Lens 8%
o Solar Tower - Eternal Power! 8%
o Methane-ba... Hydrogen-based Economy 6%
o Global Dimming - ahaha! 2%
o Painting Everything White - aaargh, my eyes! 10%
o Orbital Adjustment - muahahaha! burn crust burn! 8%
o Solar Fusion Damping - ahaha! fools! I'll melt them all! 2%
o Translucent Dyson Sphere - they said I was mad! cower, puny earthen pinklings! worship meeeee! 53%

Votes: 47
Results | Other Polls

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Supervillainy: Astroengineering Global Warming | 371 comments (347 topical, 24 editorial, 0 hidden)
Whatta Joke (2.50 / 8) (#2)
by Peahippo on Thu Apr 07, 2005 at 05:30:49 AM EST

There's just no way anything like that could be actually built for about $10B in the current American environment. Multiply by 10 for all the necessary items that the military-industrial complex adds to the equation. Hell, the environmental study ALONE will probably cost $10B. After all, you're affecting the entire planet, and most nations will naturally conclude they have a say in the matter ... leading to more studies.

About the only way this will actually get built for $10B is if somebody like Buffet or Gates gets a few investors, do all the work from a bribed country along the equator, and then sell sunlight variance to whatever nations care to pay for it. Either that, or somebody like Buffet or Gates goes insane and actually pays for everything out of their (admittedly paper-based) billions.

At any rate, large engineering projects are leaving the Human condition. The West's engineering dick has gone flaccid. I'm betting some Asian power attains real prominance in space, simply because of the possibility of having a culture that values something other than fucking over the neighbor. If any culture can and will build a space structure of such size, it'll be the Chinese or something. The West otherwise has spent its wad and is now eating its own belly for a few more percentage points. Whitey's engineering days are done.


I hate (2.00 / 2) (#22)
by Ward57 on Thu Apr 07, 2005 at 01:35:02 PM EST

your truth.

[ Parent ]
Sounds much like (none / 1) (#6)
by Booji Boy on Thu Apr 07, 2005 at 08:30:06 AM EST

Futurama'a solution: dump a giant icecube from space into the ocean every year or so. You know that was a joke, right?

This idea was actually used in a Simpson's episode (none / 0) (#52)
by prolixity on Thu Apr 07, 2005 at 08:23:22 PM EST

In which Burns blocks out the sun with a giant disc to increase Springfield's reliance on his nuclear energy.
Bah!
[ Parent ]
But (none / 0) (#111)
by naitha on Fri Apr 08, 2005 at 01:22:41 PM EST

wouldn't the atmosphere melt it just creating a shitload of rain upon re-entry?


"To listen is an effort, and just to hear is no merit. A duck hears also."
-Igor Stravinsky,
[ Parent ]
Blocking certain frequencies? (3.00 / 3) (#8)
by boxed on Thu Apr 07, 2005 at 09:52:29 AM EST

Won't plastic block things like infrared radiation much more than just diffuse it? Also the lens could be used to block ultraviolet rays, making the ozone hole a moot point.

A Venetian blind would be cheaper than a lens. (none / 0) (#10)
by Sesquipundalian on Thu Apr 07, 2005 at 10:49:55 AM EST

If you are going to cut out the "useless interior" or these concentric rings, why not make the rings out of a much less expensive, more robust opaque material, and just let in the light you want by adjusting the separation between rings.

Hell why don't we just dump a bunch of garbage at the L1 and keep replenishing it when it drifts out of alignment. The point is to create an eclipse effect, "but with holes" right? We could put radioactive garbage there at a cost of about a hundred million dollars per load instead of dumping it in the Canadian shield, and we'd be killing two birds with one stone.


Did you know that gullible is not actually an english word?
The launch costs dominate (none / 0) (#14)
by Gully Foyle on Thu Apr 07, 2005 at 12:46:18 PM EST

The material you make your satellite from is a tiny percentage of the total cost of launching it. Throwing garbage up there would probably increase your launch costs since it wouldn't be as efficient a solution.

If you weren't picked on in school you were doing something wrong - kableh
[ Parent ]

re: The launch costs dominate (none / 0) (#316)
by interstel on Mon Apr 18, 2005 at 02:13:39 AM EST

One would hope that the materials for this lens would be made in orbit from lunar materials. I would never want to have to launch all the material from Terra's surface.

Interstel

[ Parent ]
Millimeters-thin plastic. (none / 1) (#21)
by Russell Dovey on Thu Apr 07, 2005 at 01:21:28 PM EST

It's actually a lot cheaper than robust concentric rings, and the fuel costs for stationkeeping would be massive for a structure with substantial mass. We're talking essentially advanced clingwrap here.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

Won't work because photons want to move. (none / 0) (#129)
by eemeli on Fri Apr 08, 2005 at 04:57:21 PM EST

Any opaque material would work as a kind of solar sail, being slowly pushed by the impacting photons. This would quite quickly destabilise the structure and push it out of the Lagrange point. Hence the idea to use a lens to diffuse the light, not stop it.

[ Parent ]
Same thing happens (none / 0) (#139)
by Stregone on Fri Apr 08, 2005 at 08:02:02 PM EST

Defusing the light would do the same thing, just less so. An solar sail reflects the light more or less directly backwards, a lense does the same thing but only slightly changes the light's direction.

[ Parent ]
Lens does not reflect (none / 0) (#172)
by badtux on Sat Apr 09, 2005 at 02:01:08 AM EST

It just redirects. And the sum of photons coming out the back of the lens is the same as the sum of photons coming in the front of the lens, thus no net vector difference to impart force upon the lense. Well, there's inevitable losses each of which is energy imparted to the lens (thus some degree of sail-hood) but these should be very small.

The bigger problem will be that the lens will slowly erode due to the dust and energetic particles of space, slowly turning it opaque at which time it really IS a solar sail.

- Badtux the Solar Penguin
In a time of chimpanzees, I was a penguin
[ Parent ]

But they're going in a different direction (none / 0) (#264)
by Maurkov on Tue Apr 12, 2005 at 07:58:12 PM EST

In pathetic ascii:

light in    |||||
lens        ===
light out  //|||\

Since the photons are departing at an angle, they're transferring less momentum, something like the cosine of the defracted angle.  In the diagram, the lens would be pushed down.

[ Parent ]

Oops (none / 0) (#289)
by masher on Fri Apr 15, 2005 at 01:29:50 PM EST

Incorrect...there is no net force on the lens. Consider two rays of light entering two opposing sides of the lens. One is diffracted (for example) 2 degrees to the left, the other the same amount to the right. The vector sum of these diffractions is zero. The forces counteract each other.

[ Parent ]
Look at all the vectors. (none / 0) (#292)
by Maurkov on Fri Apr 15, 2005 at 04:32:13 PM EST

Still using the diagram in the grandparent, suppose an incoming ray has a velocity vector (0, -1).  A ray hitting one edge comes in with (0, -1), but leaves at a 2 degree angle, vector (sin(2), -cos(2)), and one hitting the other edge leaves with the vector (-sin(2), -cos(2)).  Sum the vectors and you get (0, -2cos(2)), which is less than the incoming sum of (0, -2).  Therefore momentum is transferred to the lens.

[ Parent ]
You're right, but... (none / 0) (#293)
by masher on Fri Apr 15, 2005 at 05:24:48 PM EST

Quite true, if I had realized I was posting to someone who actually understood the topic, I would have spoken more clearly. The lateral vectors cancel; the forward vector is reduced by 1-cos(theta), where theta is your angle of deflection. But how large is this contribution? For a point 1.5M miles from the earth and a deflection distance of ~4000 miles (radius of the earth), theta works out to ~0.15 degrees. So the momentum transferred to the lens from inpinging photons is (1-cos(0.15))*p or 3.5E-6. Or roughly 4/10,000 of a percent. In contrast, an absorptive shield would impart 100% of the momentum, and a reflective shield 200% of it. This isn't precise obviously...the actual calculation would be the integral of the varying contribution across the entire lens face, but it gets us in the ballpark. As you can see, its an exceedingly small contribution.

[ Parent ]
Keep It Simple, Stupid. Why a lense? (none / 0) (#286)
by guyd on Fri Apr 15, 2005 at 07:04:11 AM EST

As several people have pointed out, the lense idea is overcomplicated and impractical (ie over a billion cubic meters of plastic needed.) But the idea is just to block sunlight from reaching Earth. Thats easily done without any fancy fresnell lense. It doesn't even require a complete disk. Or even a solid. One easy to manufacture and deploy system would be a bunch of rolls of reflective film, fixed together at a central point, and allowed to unroll outwards, with a little spin to keep them tensioned. Like wheel spokes. An even simpler one would be to release a cloud of dust at L1. The dust particles would absorb light, heat up, re-emit in all directions - ie mostly away from Earth. The dust would drift off L1 gradually, so dump more in. At last! We'd have something useful to do with all that used photocopier toner. Actually, the dust doesn't even have to be black. Plain water vapour would do. Which would mean that the favourite of SF stories could come true - comet capture, transporting, and mining.
Emphirical Philosophy Labs
[ Parent ]
This is why (none / 0) (#290)
by masher on Fri Apr 15, 2005 at 01:38:01 PM EST

An opaque material absorbs photons, generating outward pressure. A reflective material generates twice as much pressure (read up on conservation of momentum if you're unsure why). For a large, low-density object, the solar radiation pressure more than counteracts the sun's gravity, and shifts the L1 point to just beyond the earth's orbit. A diffusing lens doesn't do this. Thats why a lens was chosen.

[ Parent ]
on this paragraph (none / 0) (#12)
by khallow on Thu Apr 07, 2005 at 12:19:39 PM EST

In any case, it is clearly impossible for us to stop global warming solely by replacing our current and future power generation with nuclear power. Quite apart from the expense of building a new nuclear power station every day for 25 years, there is not enough nuclear fuel on the planet to cope with the demand. We must think of other ways, such as solar, wind, geothermal or tidal power, architectural albedo modification (Painting roofs and roads white, since white will reflect sunlight more effectively and increase Earth's reflectivity), geoengineering (from filling the stratosphere with silver foil to burying carbon dioxide in the ocean) and lifestyle changes.

What a crock. Deforestation is responsible for around 20-30% of CO2 emissions. I see no mention here of reversing it. Second, nuclear power goes a lot further than you are claiming. There are 429 plants worldwide providing 17% (in 1999) of the world's power. Globally, I don't see any real restriction to a factor of 20 increase in nuclear fuel consumption and building a nuclear plant a day for 25 years (assuming you actually need that many) is quite feasible.

Solar, wind, etc are being developed and would probably be necessary to handle peak loads (nuclear power is used to handle the background load). Electricity storage would be valuable, but it currently is very inefficient. Albedo modification is interesting and would be useful from the viewpoint of energy conservation as well.

Lifestyle changes are IMHO poorly focused here. If there's a product or activity that is truly causing economic damage then the user should pay to perform that activity. However, when I hear that we need to make "lifestyle changes" it seems inevitably to be some sort of religious, ecological puritan streak. People are having driving SUV's or having fun, we must stop it.

Stating the obvious since 1969.

Ah, I understand now. (none / 0) (#19)
by Russell Dovey on Thu Apr 07, 2005 at 01:19:07 PM EST

Lifestyle changes are IMHO poorly focused here. If there's a product or activity that is truly causing economic damage then the user should pay to perform that activity. However, when I hear that we need to make "lifestyle changes" it seems inevitably to be some sort of religious, ecological puritan streak. People are having driving SUV's or having fun, we must stop it.

You're not responding to the article, you're just ranting. Good, ranting is good. Carry on.

Incidentally, I'm mostly a libertarian, so I agree that there shouldn't be excessive coercion here. But the disincentives against environmental collapse should be serious. The economy doesn't mean much if it's under water.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

rant magnet (none / 1) (#53)
by khallow on Thu Apr 07, 2005 at 08:31:40 PM EST

You're not responding to the article, you're just ranting. Good, ranting is good. Carry on.

You brought out the best there. I just got upset because it's not Benford's place to say that "lifestyle changes" must occur. Instead, it would have been better to say that externalities of CO2 should be accounted for. So if that CO2 emission is due to me driving an SUV, then I pay for that priviledge. Ie, I should be able to decide whether or not the extra CO2 emissions I produce is worth the cost that I inflict on the environment, and then I pay whatever price that is.

Stating the obvious since 1969.
[ Parent ]

Incidentally... (none / 0) (#32)
by Russell Dovey on Thu Apr 07, 2005 at 02:55:18 PM EST

...I am aware that yes, the world could probably, after some gearing-up time, turn out one nuclear power plant per day.

However, it would take a new Manhattan Project. Nuke plants are very expensive.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

not really (none / 0) (#54)
by khallow on Thu Apr 07, 2005 at 08:38:09 PM EST

However, it would take a new Manhattan Project. Nuke plants are very expensive.

If we wanted to do an idiotic series of Cold War-style, big engineering projects like the hundred or so nuclear plants that were built in the US prior to the Three Mile Island accident, then yes, we're going to need a lot of government squeeze to keep it going. I don't see why nuclear plants have to be that expensive. At least, we can standardize all aspects of the plant: design, construction, maintenance, and operation. Further, there appears to be several innovative designs out there that are vastly better than the old ones (eg, you no longer need to put two years worth of energy in at a time). The past isn't necessarily indicative of the future.

Stating the obvious since 1969.
[ Parent ]

Without using Google... (none / 0) (#60)
by gr3y on Thu Apr 07, 2005 at 11:40:44 PM EST

name the two major types of nuclear power plants used to generate power in the world today.

If you can, off the top of your head, and you assert that, I'll give your argument the time of day and actually post a meaningful response.

If you can't, you should stop talking about something you know nothing about.

I am a disruptive technology.
[ Parent ]

hrmm (none / 0) (#68)
by khallow on Fri Apr 08, 2005 at 04:20:29 AM EST

If you can, off the top of your head, and you assert that, I'll give your argument the time of day and actually post a meaningful response.

Ok, I failed your test. But did you have anything meaningful to say in the first place? As far as I know, there's only one type of usable nuclear reactor, a fission reactor.

I don't have a good grasp of designs of most nuclear plants, just a reasonable understanding of the mechanics. Namely, the fuel in the reactor (at least the kind that is intended to produce power) is just a heat source. The fuel is generally shaped in rods and placed in close proximity to one another to induce excess fissioning from loose neutrons. Another material is used to moderate (by absorbing) the number of neutrons emitted from these rods. The geometry of the structure sometimes helps so I hear, but I don't have an example in mind.

The reactor is cooled by some sort of gas or fluid. I gather water, heavy water, liquid sodium, and perhaps some inert gas (maybe nitrogen or a noble gas?) have been used as cooling media. The fluid apparently should be something that doesn't easily generate long-lived radioactive isotopes. The water fluids and liquid sodium are apparently ideal from that viewpoint.

Once heat is transfered to this fluid, it eventually gets transfered to a heat sink just like any working heat engine. For nuclear plants, apparently large bodies of water or rivers are used as the eventual heat sink.

When I've read up on the subject several things seem apparent. 1) in the US each nuclear plant has been more or less a unique work. Operator controlled systems and such apparently have varied so much from plant to plant that people trained in one system often need to be completely retrained for another, 2) nuclear power has been heavily subsidized so that no reasonable comparison to a truly private system can be made, 3) nuclear fuel and such is also heavily regulated to the point that one cannot even say how much certain types of nuclear fuel would cost, there just isn't a market present, ie, the economics of nuclear power is very messed up, 4) there is a vast amount of public hysteria surrounding nuclear power which has been aggrevated by the lousy incompetence of political systems exploiting nuclear energy subsidies, and 5) new reactor designs have little to do with the old. For example, pebble bed reactors are gas cooled and stable, contain less material in the reactor, and are stable in the absence of cooling unlike the more traditional liquid cooled (water, heavy water, liquid sodium, etc) reactors that contain up to two years of fuel and can be extremely dangerous in the advent that the cooling system fails.

When someone says something like "nuclear reactors are expensive" that is relative. Sure a nuclear reactor is going to cost more per installation than a windmill or natural gas turbine, and various significant problems like waste disposal that aren't quite solved yet. They produce more energy than most other types of sources. So we should be considering the total cost of producing power (including disposal costs and environmental damage).

It makes little sense to me to say that an infrastructure of nuclear plants producing all power for the world is expensive. It would be expensive no matter what the power source was. A global infrastructure of solar plants complete with energy storage capable of sustaining background load at night probably would be even more pricy.

But the reactors of the past were built under circumstances that actively discouraged cheap reactors. To insinuate that reactors today will be "expensive" because companies back then were paid enormous sums to chew up government funds doesn't mean that nuclear power is inherently costly. The technology hasn't been given a fair chance.


Stating the obvious since 1969.
[ Parent ]

Mostly correct.. (none / 0) (#74)
by ajduk on Fri Apr 08, 2005 at 06:21:02 AM EST

Although it has to be said that Nuclear power is not expensive in terms of running costs, it's the cheapest by a fair margin, even including 20% added on to the end price for decomissioning. Capital costs are quite variable, and these are the biggest single item by far. However, governments can actually do something about this.

The other issue is one of load following; it is probably best to indroduce loads that can be turned on and off, using extremely cheap off-peak electricity. Many industrial processes could be adapted for this, for example the procesing of organic waste (paper, cardboard, wood, etc) into fuels. Which, of course, reduces carbon emissions even more.

[ Parent ]

Turning paper into fuel... (none / 0) (#180)
by DavidTC on Sat Apr 09, 2005 at 01:01:49 PM EST

...increases CO2 emissions, not the other way around. Trees pull CO2 out of the air, using them as fuel puts it back.

If we want to get rid of CO2, we need to plant vast forests (Or, as some people have pointed out, vast fields of hemp, which grows a lot faster.), let them suck a bunch of CO2 out of the air, and then cut them down and bury them somewhere or make stuff out of them.

Or just get goofballs to stop recycling paper. Every single tree that you put in the ground reduces CO2.

-David T. C.
Yes, my email address is real.
[ Parent ]

CO2 Embedment (none / 1) (#192)
by Kadin2048 on Sun Apr 10, 2005 at 03:16:28 AM EST

Actually you don't really want to bury it either, because then as it decomposes the methane either pockets in the ground until released, or seeps up into the atmosphere. Back into the carbon cycle it goes. The best idea I've seen about pulling CO2 out of the cycle involves deep-ocean embedment. Basically you have a plant which isolates atmospheric carbon (and this can be done biologically or I believe chemically, although catalytic chemistry isn't my area) and then pump it way down into the ocean. Tests have shown that CO2 released below the ocean thermocline takes literally thousands of years to climb up to the surface. (I assume these tests have been done using carbon dating.)

Relative to the cost of some of the more wild-eyed ideas, which this article IMO represents, the cost of several of these plants on each coast is basically negligible. The way you'd get them built is by waiting for the cost of pollution credits to go up far enough, and then saying that anyone operating one of these plants could sell/have "negative pollution" vouchers (because they're removing carbon, duh). Then over time the government or environmental groups could buyback the pollution certificates to reduce the level of overall carbon production.

The only role I see in all this for space-based lasers or other neat sci-fi stuff is in enforcement and monitoring. If they could come up with a satellite that allowed you to monitor CO2 levels regionally, in real time, you could see who was keeping up their end of the bargain and who was letting things slide, versus how many pollution certificates they have. (And maybe you could laze the rule-breakers or something, too.)

[ Parent ]

burial isn't that bad (none / 0) (#208)
by khallow on Sun Apr 10, 2005 at 04:19:48 PM EST

Actually you don't really want to bury it either, because then as it decomposes the methane either pockets in the ground until released, or seeps up into the atmosphere. Back into the carbon cycle it goes. The best idea I've seen about pulling CO2 out of the cycle involves deep-ocean embedment. Basically you have a plant which isolates atmospheric carbon (and this can be done biologically or I believe chemically, although catalytic chemistry isn't my area) and then pump it way down into the ocean. Tests have shown that CO2 released below the ocean thermocline takes literally thousands of years to climb up to the surface. (I assume these tests have been done using carbon dating.)

Remember that most of the fossil fuels came out of the ground in liquid or gaseous form, so there are ways to keep it in the ground for extended periods of time (eg, the thousands of years time frame we're thinking about). And I frankly think there's a lot less ecological risk with underground storage.

The only role I see in all this for space-based lasers or other neat sci-fi stuff is in enforcement and monitoring. If they could come up with a satellite that allowed you to monitor CO2 levels regionally, in real time, you could see who was keeping up their end of the bargain and who was letting things slide, versus how many pollution certificates they have. (And maybe you could laze the rule-breakers or something, too.)

Accounting is the big problem with global warming. I think this may be the best idea of the bunch I've seen. To actually be able to measure compliance in real time? That's excellent!

Stating the obvious since 1969.
[ Parent ]

Whoa, tiger. (none / 0) (#149)
by gr3y on Fri Apr 08, 2005 at 11:05:35 PM EST

I'm happy you were able to convince me to respond, but you argue from the educated layman's perspective, and that isn't reasonable when nuclear reactors are involved.

The two major types of nuclear reactors (fission, because I know next to nothing about fusion) are: pressurized steam and boiling water reactors. Nuclear reactors in the United States are generally pressurized steam reactors. I am aware of no boiling water reactors in the United States. That design seems to be more common overseas - the reactors at Chernobyl were boiling water reactors. Why is this significant? Because the design of the reactor significantly impacts its safe operation. Someone aware of the difference should also be aware that the same actions applied to one type to control the reaction will not produce the same result in the other. Also, each design confers advantages which should be considered by anyone wanting to produce power by harnessing a nuclear reaction.

Chernobyl is the reason no one wants a nuclear reactor in their neighborhood (also Three Mile Island). Nuclear reactors tend to be located in sparsely populated areas because the consequences of an "incident" are extraordinarily long lasting. In a civilian installation, nuclear reactors are surrounded by three-foot thick, pre-stressed, reinforced concrete shells which are designed to survive a direct impact from a 747. Warning sirens are maintained in the surrounding communities in the event of a catastrophic event, and they are tested regularly. The federal government distributes iodine tablets to people living in the surrounding communities to prevent the uptake of radioactive iodine in the event of a catastrophe.

That said... there's no reason that the risk presented by nuclear power (fission) cannot be managed like most other risks. The nuclear plants constructed in the 70s and 80s have been much more profitable than expected, because they were built to exceed specifications, and they have been maintained. The NRC routinely extends the licenses of aging nuclear power plants. So nuclear power is cheaper by the amount of the initial capital investment in a well-designed plant whose lifetime is longer than originally expected.

I am a disruptive technology.
[ Parent ]

Err, those are two types of LW reactors (none / 0) (#171)
by badtux on Sat Apr 09, 2005 at 01:51:38 AM EST

Light water reactors are the majority of reactors world-wide, true, but are NOT the only types of reactors generating electricity in the world. Canada, South Korea, India, and Pakistan generate significant amounts of electricity using heavy water reactors, which, aside from being perfect nuclear weapons production reactors (after all CANDU was originally designed by the Brits as a backup to the Manhattan Project in case the Manhattan Project failed), also have the advantage of operating using natural uranium rather than enriched uranium. And the nations of the former Soviet Union still produce electricity with a significant number of Chernobyl-style graphite-moderated reactors, though thankfully that number is declining rapidly (those reactors are a disaster waiting to happen), not to mention North Korea, which is working on its own Chernobyl-style graphite-moderated reactors.

And these are just the uranium-cycle reactors. The French and Japanese have experimented with breeder reactors (i.e. plutonium-cycle reactors), which could provide a singificant amount of energy in the future due to their ability to bombard relatively inert U238 to create highly energetic Pu239 for use as fuel (i.e., "breed" their own fuel). We know breeder reactors work, the basic problems facing them are that a) reprocessing fuel rods to extract Pu239 and U238 is environmentally hazardous, and b) refined Pu239 is also a prized bomb-making material, thus the U.S. has traditionally been VERY leery of allowing it outside of military hands, whereas the lightly-enriched uranium in regular nuclear reactors is useless as such for making bombs. I.e., politics are what keeps breeder reactors from being useful, not science.

- Badtux the Nuclear Penguin
In a time of chimpanzees, I was a penguin
[ Parent ]

To be fair... (none / 0) (#175)
by gr3y on Sat Apr 09, 2005 at 10:59:21 AM EST

I said: "...two major types of nuclear reactors", not "two types of reactors", and you apparently agree with me that the two major types I mentioned constitute the majority of nuclear reactors world-wide.

I also said the major problem with uptake of nuclear power generation is not technological, but social (and therefore political). It seems we are in agreement there also.

I am a disruptive technology.
[ Parent ]

a point here (none / 0) (#207)
by khallow on Sun Apr 10, 2005 at 04:13:55 PM EST

I don't know the field of new reactor designs are out there, but there seems to be several key factors. First, a number of the "recent" (I understand that pebble bed, for example, has been around for at least two decades in a prototype form) designs appear safer and have less fuel in use at one time. So it's not clear to me that any of the current common designs will still be in operation in a few decades.

This is part of my original point way back when. The nuclear plants of the past fifty years are old technology and were subsidized by substantial government investments globally. We really haven't tested this technology to see if it can stand on its own without subsidies and the like. My impression is that some of the new technologies may indeed thrive in the current economic environment.

And if a small number of nuclear plants turn out to be economically competitive to fossil fuel burning designs, then we have much of the impetus needed to replace most fossil fuel plants over a couple of decades.

Stating the obvious since 1969.
[ Parent ]

Three, not two (none / 0) (#170)
by badtux on Sat Apr 09, 2005 at 01:41:24 AM EST

Okay, this is off the top of my head, I have NOT touched google in this post, so if something below is wrong, blame my memory. but anyhow:

There are THREE, not two, types of nuclear power plants used in the world today to generate electricity: American style light water reactors, Canadian style heavy water reactors, and Soviet style graphite-moderated reactors. The Soviet-style reactors are on the way out because they are very unsafe (think Chernobyl), North Korea is as far as I know the only nation still building them. The CANDU-style heavy water reactors are very safe (loss of coolant means automatic shutdown since the coolant is also the moderator) and are very popular amongst nations that want to build nuclear weapons (both India and Pakistan jump-started their weapons programs with CANDU-style reactors) but are somewhat expensive to run due to the large amounts of heavy water needed (however, supposedly the Canucks have a new generation of CANDU on the way that uses light water for cooling and heavy water as the moderator, and thus require far less heavy water for normal operation compared with the current CANDU generation that uses the heavy water for both purposes). And American-style light water reactors are very popular (even the Russians are doing light-water reactors nowdays rather than the old Soviet stuff, actually the Soviets transitioned to light-water reactors in the 1970's by stealing U.S. designs but have never managed to retire all the old graphite ones), but have the downside that they require enriched uranium (natural uranium is maybe 2% U235 and the rest is U238, light water reactors need 5-8% U235 to operate), and having the ability to enrich uranium also means you have the ability to build a nuclear bomb, which is why Brazil and Iran scare the bejeezus out of nuclear proliferation experts (Brazil already has an enrichment plant in operation, Iran will have one shortly).

Finally, regarding nuclear fuel and shortages thereof, the uranium cycle is only one of the possible cycles for powering a nuclear reactor. The plutonium cycle is another, indeed, fissioning Pu-239 (said Pu-239 created by bombarding U238 with neutrons from fissioning U235 during normal operations of the reactor) is a major contributor to energy production even in uranium-cycle reactors. What eventually causes fuel rods to cease fissioning is the buildup of "neutron sink" elements within them, but most of a fuel rod is still fissionable fuel by the time it becomes unusable, and can be reprocessed and the resulting Pu239 and U238 (and small amount of remaining U235 -- around 80% of it fissioned, typically) can be put to use in a plutonium-cycle reactor (typically called a "breeder reactor" because the neutrons bombarding the U238 during normal operation breeds more Pu239 fuel). And that's just one of the tricks, there's other fissionable elements too that can be used to fuel nuclear reactors.

The Department of Energy has a Next Generation Reactor project that has already pre-approved designs for several inherently-safe and much-cheaper next generation nuclear power plants. The French also have a next generation nuclear power plant on the boards that similarly is less expensive to build and has the same inherently-safe characteristics, but they have a problem -- almost 100% of French electricity is generated by nuclear power, so they can't build it to see if it's as good as they think it is, because they have nowhere to sell the electricity thus generated unless they retire one of their older nuclear power plants.

In any event, the biggest problems facing nuclear power today are political, not technological. The "Greens" in many nations won't allow new nuclear power plants in their countries, and the U.S. hates it when a nation like Brazil or Iran builds nuclear power plants because a nuclear power plant inherently means you have the ability to build an atomic bomb (at least, once you build a fuel reprocessing plant to seperate Pu239 from fuel rods, which is a simple chemical process that is FAR easier than seperating U235 from U238 which is a mechnical process due to the fact that U235 and U238 are chemically identical... plutonium bombs are a lot harder to build than uranium bombs, but it's also a lot easier to get plutonium than to get highly-enriched uranium). As long as having a nuclear power plant means having the ability to make big bombs that go boom, it's unlikely that the Western nations will allow anybody not already in the nuclear club to join the club unless they're REALLY willing to pay some heavy dues. Expect bombs to be falling on Iran shortly.

- Badtux the Nuclear Penguin
In a time of chimpanzees, I was a penguin
[ Parent ]

Ah yes, common mistake! (none / 0) (#72)
by tetsuwan on Fri Apr 08, 2005 at 05:03:32 AM EST

Your source says "17 percent of the electricy". I don't have the exact figure, but electricity is only about 20-40 % of the total energy consumption. SUVs, for example, are not driven by electricity (doh!).

Njal's Saga: Just like Romeo & Juliet without the romance
[ Parent ]

oops (none / 0) (#130)
by khallow on Fri Apr 08, 2005 at 05:46:08 PM EST

Your source says "17 percent of the electricy". I don't have the exact figure, but electricity is only about 20-40 % of the total energy consumption. SUVs, for example, are not driven by electricity (doh!).

I really did blow it. Some site I dimly recall, was saying that electricity was roughly 30%, transportation 40%, and heating 30%.

Stating the obvious since 1969.
[ Parent ]

Yes, you did make a common mistake. (none / 0) (#136)
by FieryTaco on Fri Apr 08, 2005 at 07:06:39 PM EST

Since the argument was to reduce the emissions of fossil fuel power plants by replacing them with nuclear. It has nothing to do with total energy consumption.

[ Parent ]
Did you even remember the overall topic? (none / 0) (#221)
by tetsuwan on Mon Apr 11, 2005 at 07:29:19 AM EST

nt

Njal's Saga: Just like Romeo & Juliet without the romance
[ Parent ]

nt (none / 0) (#241)
by FieryTaco on Mon Apr 11, 2005 at 07:14:47 PM EST

Yes. I do. It's about moderating global warming by reducing the amount of solar energy that hits the earth. It's compared to replacing a coal burning powerplant with nuclear reactors on a daily basis. But at no point was the overall topic about where different sources of energy go or what different contributors of CO2 are.

[ Parent ]
re: Ah yes, common mistake! (none / 0) (#315)
by interstel on Mon Apr 18, 2005 at 02:11:27 AM EST

If you shut down every coal and oil burning plant on the planet. Then you would significant change the pollution budget.

Interstel

[ Parent ]
re: on this paragraph (none / 0) (#146)
by interstel on Fri Apr 08, 2005 at 10:08:44 PM EST

What is most interesting is that no one ever mentions reviving the old NASA proposal from back in 1975 for the Solar Power Satellite Program.

The 30 year $3 trillion dollar project (probably more like $5 trillion now) would put 60 power satellites in orbit that were designed to deliver 3 times the global electricity needs of the year 2005. You would need to recalculate the number of satellites for say 2040 instead but once complete you could end all coal, oil and nuclear power plant operations on the planets surface.

Total project for 2040 probably 200 satellites allowing for inflation and additional satellites the cost might sit somewhere around $30 trillion over 30 years. Or about a $1 trillion a year. Completely doable globally. And of course as each satellite goes online it begins making money.


Interstel

[ Parent ]
OK Clever Cloggs (none / 0) (#236)
by I Hate Yanks on Mon Apr 11, 2005 at 04:49:11 PM EST

How do do yuou get the power generated by the satelites to the Earth?


Reasons to hate Americans (No. 812): Circletimessquare lives there.
[ Parent ]

I suspect you know already, but... (none / 0) (#242)
by Russell Dovey on Mon Apr 11, 2005 at 07:57:56 PM EST

...i'll humour your juvenile attempts at trolling:

Two options:

  • Microwave beaming. Old idea, look it up.
  • Space elevator, self-explanatory.
Enough, heathen?

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

So (none / 0) (#259)
by I Hate Yanks on Tue Apr 12, 2005 at 06:23:57 AM EST

What happens when a bird or a plane or a cloud passes through the microwave beam?

What happens if the satelite gets knocked and the microwave beam ends up where it wasn't intended to be? Ooops, we just microwaved Chicago?


Reasons to hate Americans (No. 812): Circletimessquare lives there.
[ Parent ]

I said LOOK IT UP! (none / 0) (#267)
by Russell Dovey on Wed Apr 13, 2005 at 01:50:44 AM EST

You didn't, or you would have known that the danger of a plane or bird being fried by a powersat's microwave downlink is akin to being fried by a mobile phone tower.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

re: I said LOOK IT UP! (none / 0) (#314)
by interstel on Mon Apr 18, 2005 at 02:09:19 AM EST

Ah, its soon nice to see others who know about such things. Thank you for restoring some of my faith in intelligent humans.

Interstel

[ Parent ]
re: So (none / 0) (#313)
by interstel on Mon Apr 18, 2005 at 02:08:08 AM EST

AH, it would take a very large impact to roll one of the SPS satellites since they 1 mile long and a 1/2 mile wide.

Secondly, since the satellites would have absolute positional information the beam would shut down automatically once it began to deviate by even an inch.

Finally, I suggest as the other poster did, look up microwave transmission systems. They DO NOT work like your microwave oven.

Interstel

[ Parent ]
re: OK Clever Cloggs (none / 0) (#312)
by interstel on Mon Apr 18, 2005 at 02:03:41 AM EST

The original SPS Project called for microwave rectennas. Basically you build a microwave transmission receiving farm typically X number of miles in diameter. The power is beamed from the orbiting satellites to these receivers and they in turn translate power into the local power grid. I would have to dig up the documents (I ordered them back in the 70's and saved them) to give you the energy level but if memory serves me it was low enough not to cook you if you stood in the field.

Mind you there has been a whole bunch of new discoveries since then. I've seen numbers that you can build space needles for $15-20 billion and they could act as bulk power delivery systems.

Interstel

[ Parent ]
interesting point (none / 0) (#282)
by khallow on Thu Apr 14, 2005 at 04:30:33 PM EST

With that kind of infrastructure in space, you probably could move a lot of industry into space as well.

Stating the obvious since 1969.
[ Parent ]

re: interesting point (none / 1) (#311)
by interstel on Mon Apr 18, 2005 at 01:59:48 AM EST

And you have just made the standard L5 Society response. Once you start working in orbit and building facilities from lunar materials manufacturing capabilities for lots of other areas can be moved there to.

In turn reduction global polution by magnitudes.

Interstel

[ Parent ]
Not a coincidence... (none / 0) (#318)
by khallow on Mon Apr 18, 2005 at 12:24:55 PM EST

since I'm a member of an unofficial chapter of the L5 Society (which merged in 1987 with the National Space Institute). Some people are still carrying the flame. :-)

Stating the obvious since 1969.
[ Parent ]

re: Not a coincidence... (none / 0) (#322)
by interstel on Tue Apr 19, 2005 at 08:37:20 PM EST

<grin>

And thanks to Burt Rhutan. Things are beginning to look like we might have a shot again for ourselves!

Interstel

[ Parent ]
and predictions of "failure" (none / 1) (#13)
by khallow on Thu Apr 07, 2005 at 12:31:04 PM EST

[...], while the continuing progress of the 1-kilometre high, no-emission, oxygen-producing, 200-megawatt Australian solar tower which will be built by 2009 at Buronga, 25 ks east of Mildura in New South Wales, can be found here. The project has just recently purchased the land they plan to build upon, and has so far defied the usual predictions of failure that accompany any new way of doing things. Here's hoping that the Solar Tower is successful, just so some madman decides to build a 2-kilometre high one to show up those damn Aussies.

That's not that impressive an accomplishment since nothing has been built yet. Also, last I checked the tower isn't using plants in the design (plants absorb sunlight readily but they also cool the local atmosphere), so it isn't "oxygen-producing".

Stating the obvious since 1969.

Didn't look at it too closely then. (none / 0) (#17)
by Russell Dovey on Thu Apr 07, 2005 at 01:14:50 PM EST

True, it's not successful yet. That's why I hope it will be.

And one of the great things about the design is that you have a square kilometre of plastic a couple of meters above the ground around the tower. In other words, a big feckoff greenhouse, in which crops can be grown to offset overhead. As long as they're low crops, the airflow won't be affected.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

on growing crops here (none / 1) (#51)
by khallow on Thu Apr 07, 2005 at 08:18:50 PM EST

In other words, a big feckoff greenhouse, in which crops can be grown to offset overhead. As long as they're low crops, the airflow won't be affected.

Maybe I was mistaken about the degree of the problem, but plants would steal energy from the solar plant. There are two ways. First, the plants would use the light to generate sugars, etc. The energy consumed then isn't available to generate power. Second, plants transpire. Ie, they cool off through water evaporation from the leaf's surface. Again it takes energy to evaporate this water. Having said this, there might be some regime where the economics make sense. Maybe in very cold climates during the summer months?

Stating the obvious since 1969.
[ Parent ]

I like the plan of (2.80 / 5) (#15)
by army of phred on Thu Apr 07, 2005 at 12:59:26 PM EST

taxing energy use to an exhorbitant amount. For instance, I could easily afford $10 a gallon for gas yet that would obviously put the burden upon folks who have wasteful lifestyles like commuting long distances to work instead of sharing apartments with 20 of your closest friends inside the city.

Really, make polution the expense it really is, instead of shifting the expense to future generations.

"Republicans are evil." lildebbie
"I have no fucking clue what I'm talking about." motormachinemercenary
"my wife is getting a blowjob" ghostoft1ber

Totally agree (none / 0) (#237)
by I Hate Yanks on Mon Apr 11, 2005 at 04:52:29 PM EST

If the cost of pollution was bourne by the polluters then no-one could afford to pollute.

Now you just need some formulae that will calculate the total cost of pollution for each electricity-production method.


Reasons to hate Americans (No. 812): Circletimessquare lives there.
[ Parent ]

An idea worthy of an evil genius. (2.40 / 5) (#16)
by Kasreyn on Thu Apr 07, 2005 at 01:01:29 PM EST

Though of course, you're going to have the damnedest time getting that 10 billion from anywhere. Billons for war! Not a cent for the future! That's our race's motto.


"Extenuating circumstance to be mentioned on Judgement Day:
We never asked to be born in the first place."

R.I.P. Kurt. You will be missed.
'Tis nothing for Dr Evil (none / 0) (#235)
by X3nocide on Mon Apr 11, 2005 at 04:41:00 PM EST

Think of it as an investment in evil. Put up ten billion, and now you can sell survival to interested   countries. Muwahaha.

pwnguin.net
[ Parent ]
Its easier (3.00 / 3) (#20)
by minerboy on Thu Apr 07, 2005 at 01:19:12 PM EST

To take a lesson from the Amish - Use horses, buy only Local products (no energy for shipping), Don't spend so much on health care so you can die at an earlier age, Don't own technology that will prop up 3rd world overpopulation, Use Biomass fuels (wood, and methane generated from decaing manure), Use low yield, low impact farming so you can only feed people locally, and accept the population the land will support. Don't travel much so that you won't spread disease, and allow epidemics to cull the population. Back to nature, no more global warming yay !!



Look, it's not because you're annoying. (3.00 / 2) (#26)
by Russell Dovey on Thu Apr 07, 2005 at 02:36:22 PM EST

Well, it is. But it's me too.

We just can't go on like this, minerboy. Your strange ways are incompatible with my free and easy existence. I like to drive SUVS through the forest crushing rare orchids, you like bicycling on marked footpaths, crushing pedestrians. I like buying food that has come from the other side of the globe, redolent with mystery. You like eating potatoes grown in the yard.

So I want the key to the donkey.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

want the key to the donkey ? (none / 1) (#33)
by minerboy on Thu Apr 07, 2005 at 03:02:10 PM EST

Is that some odd gay kiwi saying or something ?



[ Parent ]
if we are going to take a lesson (none / 0) (#75)
by m a r c on Fri Apr 08, 2005 at 07:40:49 AM EST

then lesson one would be, have multiple wives ;)
I got a dog and named him "Stay". Now, I go "Come here, Stay!". After a while, the dog went insane and wouldn't move at all.
[ Parent ]
There is no.... (none / 0) (#116)
by gte910h on Fri Apr 08, 2005 at 02:27:06 PM EST

Overpopulation
or
Energy Crisis

There is simply an overabundance of CO2 and CH4 and H20 in the atmosphere


[ Parent ]

Roman Empire (none / 0) (#169)
by badtux on Sat Apr 09, 2005 at 01:16:41 AM EST

The Romans lived like this. Once the population of the Empire grew to the point where the soils of the Empire were exhausted and the supplies of wood were exhausted, the Empire collapsed, as did the population of the former Empire. Rome had close to 2 million people in 300AD. By 500AD, there were only a few thousand huddled survivors living in misery in the ruins of a city built for far more. The rest had either died, or fled to the countryside to become farmers (and most of THEM died too, the Western Empire at its peak had around 100 million people, it is estimated that by 500AD there were less than 20 million survivors left in Western Europe).

This cycle of empire and collapse has been the norm for most of human civilization. While topsoil and wood are renewable resources, they take hundreds of years to renew. And humans tend to reproduce to the point where they exhaust all available renewable resources, thus causing another population collapse as disease, starvation, and exposure (due to lack of wood for heating) take their toll. And that collapse often takes civilization as a whole out with it, at least in the area of resource exhaustion.

So yes, we can go back to 300AD. But remember, by 400AD the Roman system was in full collapse due to resource exhaustion, and by 500AD, there was nothing left of it in the West but legend handed down from parent to child over the decades. Going back to 300AD is a recipe for a new Dark Ages, one from which we might never recover.

- Badtux the Historian Penguin
In a time of chimpanzees, I was a penguin
[ Parent ]

Fuck all that. (none / 0) (#188)
by Fon2d2 on Sun Apr 10, 2005 at 12:05:39 AM EST

If ever I've seen the romanticism blown out of the Amish lifestyle, this was it.

[ Parent ]
Solar Windmill (3.00 / 2) (#29)
by pauldamer on Thu Apr 07, 2005 at 02:47:32 PM EST

Hmm, if you oriented the microlenses so they radiated outwards instead of being in concentric circles you could use the light being diffused to help it rotate. Sort of like a solar sail but instead just a solar windmill.

Um, no (none / 0) (#39)
by codejack on Thu Apr 07, 2005 at 05:20:46 PM EST

Sorry, solar winds don't work that way: You can't "tack" against it.


Please read before posting.

[ Parent ]
What if you shape it like a windsock instead? (none / 0) (#57)
by Scrymarch on Thu Apr 07, 2005 at 10:22:16 PM EST

Mind you, windsocks have anchors.

[ Parent ]
That has nothing to do with it (none / 0) (#61)
by codejack on Thu Apr 07, 2005 at 11:52:16 PM EST

A windsock still works on the same principles as "tacking" a sailboat: You have to have a medium to push against, whether it be water, an anchor, whatever. There is no such medium in space. For that matter, the same principles allow propellers to work, and put that way, it's obvious, right?


Please read before posting.

[ Parent ]
Nearly (none / 0) (#62)
by Scrymarch on Fri Apr 08, 2005 at 12:00:38 AM EST

I understand why a solar sailboat can't tack, the keel and rudder won't work because as you say there's no medium to push against.  Without the anchor I presume the sail would be moved away from the sun, radially, at a rate determined by its profile.

But I think you could put an anchor on your solar sail, and then you've got a solar windsock.  Perhaps a small heavy spacecraft which attempted to move very slowly towards the sun.  The small profile and weight would mean it wasn't pushed as fast as the sail behind it, which would be pulled around to stay facing the sun.

[ Parent ]

Actually, you have something to push against (none / 0) (#64)
by Nameless on Fri Apr 08, 2005 at 01:12:30 AM EST

Actually, you have something to push against. And that is gravity. If you refract the light (or reflect it) in any direction that is not directly away (or towards) the sun, then you get a sideways component to the push. Gravity pulls you directly towards the sun, so the resulting force will allow you to "tack".

[ Parent ]
No! (none / 0) (#88)
by codejack on Fri Apr 08, 2005 at 10:37:27 AM EST

First, go read up on solar wind: It has nothing to do with light, and you cannot reflect or refract it. Second, if you are balancing the force of the wind against the force of gravity, nothing happens, as there is no "siedways component" as you cannot reflect and/or refract solar wind.


Please read before posting.

[ Parent ]
Why not? (none / 0) (#98)
by inkieminstrel on Fri Apr 08, 2005 at 11:27:48 AM EST

What stops you from deflecting the solar wind? No, it's not light, it's mostly high energy protons, but protons can also be deflected by e.g. a magnetic field.

[ Parent ]
Because (none / 0) (#99)
by codejack on Fri Apr 08, 2005 at 11:33:28 AM EST

The protons that compose the solar wind stick to whatever they hit. Even a magnetic field doesn't "deflect" solar wind, it traps it. For examples, look up solar wind, aurora borealis, etc.


Please read before posting.

[ Parent ]
Solar Wind can be deflected (none / 0) (#112)
by radtea on Fri Apr 08, 2005 at 01:41:22 PM EST

Magnetic fields do deflect moving charged particles, which is what the solar wind is composed of: F = q v X B. They get trapped when the force is sufficiently strong that the curve is closed. So you can deflect the solar wind, and therefore tack against it much as you can light with a lightsail tilted with or against the orbital velocity. In practical terms, I am very doubtful it would be worth wasting the back of an envelope to prove how hard it would be. On the other hand, Vannevar Bush--the head of the U.S. Army rocketry program at the end of WWII--once said we'd never go to the Moon because you'd have to take a rocket the size of a battleship, stand it up on end, and launch it into space, and no one would ever have the balls to do that... --Tom

[ Parent ]
Are you sure you can tack? (none / 0) (#143)
by Scrymarch on Fri Apr 08, 2005 at 09:09:51 PM EST

You may already know this ...

A sailboat works two ways - when the wind is behind it, the wind fills the sail and the boat is pushed along straightforwardly.  You could tilt the direction at which the wind is deflected (metaphor shear here) and therefore steer (pending codejack's next outraged exclamation) with the wind behind you.  This was the only way triremes and many medieval sailboats worked, they were square sails.

The second way is when you face into the wind, or rather 30 degrees to either side of the wind direction.  The sail - which is set in a different shape - acts as an aerofoil and generates lift, which is then transmitted into a useful direction by the keel and rudder.

Even if you got something that fancy to work with the magnetic field you haven't got a medium for a keel to push against and transmit it into forward motion.  With the combination of lift and gravity the most you could achieve is a very slow spiral into the sun, which would be slower than the action of gravity alone.

[ Parent ]

No outraged comment (none / 0) (#147)
by codejack on Fri Apr 08, 2005 at 10:12:34 PM EST

You've got it pretty well down now.


Please read before posting.

[ Parent ]
You're in an orbit. (none / 0) (#210)
by FieryTaco on Sun Apr 10, 2005 at 07:49:32 PM EST

Given a large mass to be in orbit around (the sun) and a means of propulsion (interaction with the solar wind or light) you can slow your orbital motion which would cause you to be drawn into a closer orbit. So even though your means of propulsion is directly against the direction you want to travel, you can still go in that direction.

[ Parent ]
Yes, you can tack... (none / 0) (#288)
by masher on Fri Apr 15, 2005 at 01:26:08 PM EST

You don't need a keel to push against. You need the end result a sailboat keel gives you-- which is a vector force in any direction that doesn't align with your deflective force. Given those two forces (and the ability to vary the magnitude of at least one of them) you can then "tack". Increase or decrease one force, and you change both the magnitude AND direction of the resultant vector sum.

[ Parent ]
Tacking (none / 0) (#109)
by Maurkov on Fri Apr 08, 2005 at 12:52:06 PM EST

Forgive me if I'm saying the same thing.

An object stays in orbit because it has a velocity perpendicular to the pull of gravity.  If the object speeds up, it moves into a higher orbit.  When a solar sail reflects or refracts light in the direction of travel, it produces thrust in the opposite direction.  The sail slows down and falls into a lower orbit, tacking towards the sun.


[ Parent ]

Grrrr! (none / 0) (#87)
by codejack on Fri Apr 08, 2005 at 10:35:29 AM EST

NO! Again, it doesn't work this way; This has nothing to do with "keel" or "rudder", and certainly nothing to do with an "anchor". These things do not function in space.

And if you have a ship moving towards the sun as an "anchor", then you'e just defeated the entire purpose of the exercise, which is to use solar wind rather than other fuel.


Please read before posting.

[ Parent ]
Secondary mirrors. (none / 0) (#135)
by FieryTaco on Fri Apr 08, 2005 at 07:01:20 PM EST

If you didn't want to use rocket fuel, you put up some secondary mirrors in a larger orbit around the sun and let them shine on the back of your primary mirror and use that to counter the pressure. To stabilize those? Put them at L4 & L5.

[ Parent ]
I can't stand it... (none / 0) (#151)
by codejack on Fri Apr 08, 2005 at 11:22:24 PM EST

Do you people even bother reading about stuff before you post like you know all about the sub-

Never mind, stupid question; Of course you do.

I don't even know where to begin here. First, a solar sail doesn't use light, it uses the solar wind, which cannot be reflected, so mirrors are useless. Second, this whole discussion has been an exercise in efficiency and elegance, which everyone seems to be ignoring in their search for cruder and more complicated solutions.


Please read before posting.

[ Parent ]
Yer just stupid. Learn to deal. (none / 0) (#184)
by FieryTaco on Sat Apr 09, 2005 at 09:08:09 PM EST

Yes, I do have an understanding of what a solar sail is and yes it does use light, you fucking moron. For some reason you think because it is called a "sail" it must involve something called a "wind" and so you made the completely wrong connection that a solar sail had something to do with the solar wind. How about you go and get a clue then come back and rejoin the discussion. You might want to start at the Planetary Society where they are taking part in an actual solar sail mission launching in roughly three weeks.

Have a nice day you completely ignorant penis wrinkle.

[ Parent ]

Dude (none / 0) (#142)
by Scrymarch on Fri Apr 08, 2005 at 08:43:30 PM EST

I said I understood why keels and rudders didn't work in space.

I've mulled over this solar windsock though, and it bloody well does work (well assuming the numbers work out which I'm too lazy to contemplate).  It will work even if the engines on the spaceship are turned off.

The solar wind will exert less force on the small profile of the spaceship than the wide area of the sail.  The spaceship, considered alone, will be falling towards the sun because of gravity, but the sail will (net) be moving away from the sun as the solar wind will overcome gravity.  Combine the two in the one system and you could match the weight of the ship against the force of the sail.  The sun moves relative to the system but the spaceship is always pulled towards it, turning the system.  You'd have to be careful the sail didn't crumple is all.

It's a solar parachute.

[ Parent ]

/cry (none / 0) (#152)
by codejack on Fri Apr 08, 2005 at 11:33:14 PM EST

I'm really trying, here, you know? I don't want to start insulting people, or turn it into a flame war, but posts like this make it really tough. I'll try to explain why this won't work.

You have two forces at work here: Gravity and solar wind. These forces are diametrically opposed. While, in theory, your "windsock" would work, it would do so only under the condition that the ship you are using remains at an angle to the line connecting the solar sail and the sun. Unfortunately, unless you actively move the ship, the sail will "tack" sideways until the ship is between it and the sun, at which point, the forces are diametrically opposed, at which point it stops "tacking" and, moreover, the sail is in the shadow of the ship and ceases to work altogether. Ships can execute these maneuvers because of the difference in motion of wind and water currents, which are very rarely diametrically opposed. Gravity and solar wind are different not only in degree, but in kind, as well. Please, PLEASE, look up some information on this before posting again.


Please read before posting.

[ Parent ]
I agree (none / 0) (#186)
by Scrymarch on Sat Apr 09, 2005 at 10:45:57 PM EST

Unfortunately, unless you actively move the ship, the sail will "tack" sideways until the ship is between it and the sun, at which point, the forces are diametrically opposed, at which point it stops "tacking" and,

I agree that this is what will happen.  This is the behaviour we want.  That's a description of a windsock.  (As your quotes imply it's not a tack, it's a steer.)  At the start of this we wanted to keep the lens between the sun and the earth.  And this system moves to follow the sun, while not being pushed away from or falling into the sun.

moreover, the sail is in the shadow of the ship and ceases to work altogether.

I was thinking the ship would be much heavier and smaller than the sail, so the sail would still be affected by wind even when the ship is in between.

A windsock doesn't tack, it fills with wind, and that's why this system is possible.

[ Parent ]

wtf? (none / 0) (#206)
by codejack on Sun Apr 10, 2005 at 01:19:09 PM EST

So now you are limiting it's movement to orbital motion? It's a kite. It won't do anything.


Please read before posting.

[ Parent ]
It will ... (none / 0) (#260)
by Scrymarch on Tue Apr 12, 2005 at 07:20:47 AM EST

It will cut the amount of the sun reaching the earth, as per the global warming application above ...

[ Parent ]
I'm not sure you're right. (none / 0) (#82)
by pauldamer on Fri Apr 08, 2005 at 09:03:26 AM EST

the light refracting outwards from a solar windmill configuration would generate two components of force. One would be directly outwards from the sun, the other would be perpendicular to it and to the radius of the windmill. The first would push the windmill away from the sun, the second would apply torque to the windmill. It's been a while since I've taken physics.

[ Parent ]
For the last time, no! (none / 0) (#89)
by codejack on Fri Apr 08, 2005 at 10:40:00 AM EST

Could you at least go read about solar wind before making these comments? Last time, for the cheap seats, SOLAR WIND IS NOT LIGHT!!!


Please read before posting.

[ Parent ]
I'm not talking about wind. (none / 0) (#115)
by pauldamer on Fri Apr 08, 2005 at 02:09:17 PM EST

Since wind is not refracted by prisms it would only push outward from the sun. I'm talking about light.

[ Parent ]
Of course! (none / 0) (#148)
by codejack on Fri Apr 08, 2005 at 10:19:33 PM EST

Brilliant, simply brilliant! Except of course for the facts that:
  1. We are talking about solar wind, not light, because:
  2. The light from the sun will not begin to produce enough force to move much of anything.



Please read before posting.

[ Parent ]
Again, I'm not sure you're right. (none / 0) (#182)
by pauldamer on Sat Apr 09, 2005 at 05:58:59 PM EST

This seems to say that light pressure is greated than pressure from solar wind.

http://www.planetary.org/solarsail/chaptertwo/2cover.html

[ Parent ]
Not wind. Light. (none / 0) (#105)
by Maurkov on Fri Apr 08, 2005 at 12:33:27 PM EST

Dispite the name, solar sails are powered by light, not solar wind, and they can tack.

His idea would work, though with no air resistance to counteract, it wouldn't be helpful.

[ Parent ]

J.O.O.C. (none / 0) (#134)
by FieryTaco on Fri Apr 08, 2005 at 06:58:21 PM EST

Just out of curiousity, why are you arguing with people about the "solar wind"? The only person who talked that way is you. Everybody else is talking solar sail or "solar windmill" and the main theme of the OP is a lens. All operate on light. And you can tack against it.

Additionally, as someone above posted, you could have two counter rotating mirrors with a generator between them and then use the power generated to power an ion thruster to keep you positioned. Or possibly not, I'm not a rocket scientist. But I do know that your ongoing argument that the "solar wind" can't be sailed/tacked/influenced/etc. is beside the point since everybody else is talking light. But even so, if the solar wind has a charge or mass (it has both), you can interact with it.

[ Parent ]

I think you'd need two "windmills" (none / 0) (#65)
by jsnow on Fri Apr 08, 2005 at 01:32:30 AM EST

rotating in opposite directions along the same axis, and exerting equal torque. Between and connecting the two could be a generator, which would introduce drag to slow them both down. This is very important, since in space, if a small torque is applied to an object over a long time with nothing to slow them down, it will eventually spin fast enough to fly apart.

[ Parent ]
Regarding the solar tower (2.50 / 2) (#34)
by LilDebbie on Thu Apr 07, 2005 at 03:18:11 PM EST

While the idea is pretty cool from the standpoint of its elegant simplicity, I wouldn't call it an exactly efficient use of resources. Something that big is going to require a helluva lot of concrete and glass (or whatever they're using for the greenhouse).

My other concern is, how in the hell do you turn such a power station "off" in the event you need to repair a turbine? Do you just cap the top and work in baking heat?

My name is LilDebbie and I have a garden.
- hugin -

Turbine? (1.00 / 3) (#238)
by I Hate Yanks on Mon Apr 11, 2005 at 04:58:16 PM EST

What backward country did you go to school in?

Your punishment for being so dumb is to write a 3,000 word essay on "Why solar power plants do not need turbines to generate electricty.


Reasons to hate Americans (No. 812): Circletimessquare lives there.
[ Parent ]

The Solar Tower (3.00 / 2) (#240)
by proletariat on Mon Apr 11, 2005 at 07:04:37 PM EST

has 32 turbines. You don't have to be such a jerk when you correct people - especially when you're wrong.

[ Parent ]
Man, you're an upchucked piece of snot. (2.50 / 2) (#244)
by Russell Dovey on Mon Apr 11, 2005 at 09:37:09 PM EST

As much as I love it when people reveal their ignorance in so startling a fashion, with you... it just isn't that startling.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

I see wars coming (none / 1) (#37)
by Psychopath on Thu Apr 07, 2005 at 04:50:05 PM EST

..wars about who can control this thing. ;)
--
The only antidote to mental suffering is physical pain. -- Karl Marx
Yeah... (none / 0) (#153)
by skyknight on Fri Apr 08, 2005 at 11:53:18 PM EST

we'll focus it on China like a magnifying glass to fry ants.

It's not much fun at the top. I envy the common people, their hearty meals and Bruce Springsteen and voting. --SIGNOR SPAGHETTI
[ Parent ]
Didn't C. Montgomery Burns ... (3.00 / 2) (#38)
by Mr.Surly on Thu Apr 07, 2005 at 05:20:16 PM EST

... do this to Springfield?  

So that's why winter was so mild here. (none / 0) (#50)
by mcgrew on Thu Apr 07, 2005 at 07:32:40 PM EST


"The entire neocon movement is dedicated to revoking mcgrew's posting priviliges. This is why we went to war with Iraq." -LilDebbie
[ Parent ]

Some problems (3.00 / 9) (#41)
by Polverone on Thu Apr 07, 2005 at 05:42:49 PM EST

As much as I love an excuse for turning science fiction into fact, there are some problems here. Apart from the huge bulk of plastic needed, the plastic also needs to be transparent in most frequencies (not just visible light, unless you really want to gamble) and not degraded by high vacuum and strong UV radiation. Even more interesting, I've skimmed the recent Millenium Ecosystem Assessment report and it looks like global warming is not the most urgent problem facing humans and the earth they depend on. Direct habitat destruction, lack of clean water, and disease outbreaks are higher up on the list, for example.

I'd heard "rich Westerners consume all the resources and therefore rape the planet at the expense of the poor" often enough to believe it to be true, but the report indicates that large populations are more destructive than rich populations. In matters of water quality, public health, habitat elimination, and ecosystem destruction, poor developing regions are doing far worse than the West. Forest cover is increasing and becoming a larger CO2 sink in developed nations, while it's being cut down and burned to provide fuel and habitable space in developing countries. Endangered species are protected in industrialized nations and actively eliminated in poor, overcrowded ones.

Until 100 years ago or so, the entire world experienced flat or moderate population growth. Then the West managed to apply science to health matters, making great strides against disease. The industrialized world learned how to keep children and mothers from dying, but growth rates didn't shoot up dramatically because big families aren't as advantageous in industrialized societies. The growth rate in the West peaked around 50 years ago in the "Baby Boom" and has been falling ever since. Especially after WW II, developing nations were given public health programs that also kept their mothers and children from dying -- hurray! And they were given food and agricultural techniques to keep starvation at bay -- hurray! But they weren't industrialized and kept on giving birth to lots of children. For some nations, every generation for decades has been a Baby Boom generation. Their sheer numbers are depleting natural capital at a furious rate, mostly because well-meaning powerful people from the West initiated grand programs to make things better.

There are no grand, simple solutions that will let humans live on earth in comfort, indefinitely, without changing. Lots of little changes all over really are necessary, even though it would be much more inspiring and fun if all we needed was The Apollo Project II: Earthshield. Much of the world isn't making the difficult decision about whether to rely on nuclear power or a giant space sun blocker, but about whether to have 3 or 4 children and where to get more firewood and meat once the local landscape is stripped bare. The real problems are down here on earth, and even harder to solve than you've imagined.
--
It's not a just, good idea; it's the law.

I've always wondered... (none / 0) (#187)
by Fon2d2 on Sat Apr 09, 2005 at 11:56:27 PM EST

why there is so much poverty in developing nations. I've come to some answers here and there. For example, reading up on Heart of Darkness has taught me that some of it is due to simple exploitation. But other sources would have me believe it's also due to exploitation of a less direct source, such as IMF loans and policies designed to weaken the sovereignity of poor nations.

All of this didn't quite add up though, for a couple of reasons:

First, all the first world nations seem to be doing fine. No cartel or conspiracy is so perfect they can maintain status quo indefinitely. We should see some highly developed nations coming out of Africa and South America if the above were the only reasons. So it may be just a matter of a late start. That makes sense, and is best observable with China and India. So maybe the other developing nations just got started last.

Second, there's still the issue of the poverty. When I think back to pre-colonialism, granted I don't know what it was like, but I don't imagine untold multitudes living in shanties drinking sewage-infested water. I know populations didn't spiral out of control like they do now. Is there any example of a pre-industrial society that did? So why all these poor countries now?

That leads into a different and tangentially related question, which is also answered by your post however. It's common for modern first-world countries to have very low birth rates. I know it used to be very common to have much larger families and lots of children. If the trend is decreasing, why hasn't the world population soared until just recently.

But I think you've answered all of this fairly well. Better than I've heard it so far at any rate. Not all intentions need to have been bad to lead to present day circumstances. And disease is something I've only recently started taking into consideration. Of course disease would have played a lot heavier role in population control in the past. It's all a matter of imperfect transfer of lifestyle and technology, which for the most part is rather intuitive. It's just a matter of how.

[ Parent ]

I remember a few examples (none / 0) (#212)
by Mr Plow on Sun Apr 10, 2005 at 09:54:53 PM EST

I know of two examples of pre industrial societies using up all their resources and wiping themselves out.

One of them was Easter Island where they destroyed all their forests to make giant statues. When the forests were gone they no longer hand enough natural resources to survive and they all died out. You could probably google or wiki for more info.

The other one I heard about was in a documentary whi about a region in early Europe where they chopped down cleared the forests to the point where their civilisation was no longer sustainable. I can't remember the name of the doco or any more details though if I can dig up any more info on it I'll post it here.



[ Parent ]
Heard about both of those... (none / 0) (#231)
by Fon2d2 on Mon Apr 11, 2005 at 12:22:31 PM EST

but I would say that's a slightly different issue: that or resource depletion. So if we were going to relate that to modern day, we'd be talking about oil reserves.

But my question was about the contrast between two different conceptions I have. Note that my conceptions are probably heavily influenced by the media and that may be part of the problem.

1st: The pre-industrial, pre-colonial tribe lifestyle as sustainable and low-impact. Certainly they didn't have all the modern standard of living improvements that make such a big difference to us westerners (health care, plumbing, electricity, sewage treatment) but neither were they living in overcrowded shanties drinking sewage, and by their own standards, they probably were not considered poor.

2nd: The post-industrial, post-colonial poor nation lifestyle as desperately poor and in need of serious aid, with millions starving, living in shanties, and drinking sewage with somehow no real options available to them to acquire their own food or safe drinking water because somehow they're a small player on a global stage and there's lots of internal conflicts and it gets all complicated and I don't really understand it anymore and yet despite their poverty they still seem to have babies like mad and somehow always seem to have millions starving although it makes you wonder how the population is being supported enough that there can always be these millions in the first place yet not supported enough that they are always hungry.

[ Parent ]

Bad Science, Bad Article (1.60 / 10) (#43)
by pHatidic on Thu Apr 07, 2005 at 06:20:57 PM EST

First, you make the claim that 2030 will be the "tipping point" where global warming will start to increase very quickly because more natural CO2 will be released. However, you never cite where this CO2 will come from or link to anything which supports this will happen.

Second, you never say why there are different estimates for how fast temperatures will rise. The reason is that we do not understand very will the number one greenhouse gas--drumroll please--water vapor. We know that as the earth heats up more water will be in vapor form, but we don't know where in the atmosphere it will go. Because of this it is impossible to determine how much the climate will rise.

Thirdly, I have heard it is possible that the oceans are acting as a carbon sink, absorbing some of the CO2 and slowing down global warming, and when the oceans hit capacity global warming will increase very rapidly. This seems to be what you are refering to, however as far as I know this theory is completely unproven and has never even been properly studied.

Even if the carbon sink theory is true, we have no idea what the ocean's capacity for CO2 is so it would be impossible to tell what the timeframe is. For all we know, we may already be past the tipping point.

I know the global warming is the number one problem the earth faces, but this article really doesn't do justice to this problem. As far as I know it is based on unsound or nonexistant science. You say NASA came up with some numbers, but you never cite anything to prove this. In fact most of your claims are completely uncited.

-1, use edit queue

What's on your screen? (none / 1) (#46)
by stigmata on Thu Apr 07, 2005 at 06:56:53 PM EST

I don't know whats on your screen, but on mine it says "Op-ed" near the top. That means this isn't a science term paper or professional article for a science journal, so it doesn't need to have every fact laid out and cited perfectly. Its an opinion on a possible solution to global warming with more focus on the particular solution than on the causes of global warming itself.



"But like all puppets you think you're actually human. It's the puppets dream, being normal. "
[ Parent ]
Heh (none / 1) (#47)
by pHatidic on Thu Apr 07, 2005 at 07:08:45 PM EST

Op-Ed means that you are allowed to have an opinion which may or may not be supported by facts, but it does not mean that you get to make up facts to support your opinion. Consider the follow paragraph:

Stopping global warming by 2030 is vital because it is a tipping-point where the rising temperatures begin to trigger the release of carbon dioxide and methane from natural sources, which raise temperatures, which release more carbon etc; in other words, after the expected temperature rise by 2030, we will experience a runaway greenhouse effect resulting in huge increases of eight degrees Celsius or more by 2100.

No support or references at all. For all I know this is a completely made up fact. My college major is "Natural Resources" and so half of what we do is studying global warming, but I have never heard this and I don't believe it to be true.

[ Parent ]

I don't have a major in anything scientific (none / 0) (#55)
by D Jade on Thu Apr 07, 2005 at 08:40:09 PM EST

But I have heard this supposition many times on science documentaries and news shows. As a scientist, you should know that just because you haven't heard it, doesn't mean it's not a factual supposition.

One thing that is true is that it is getting much warmer. We have seen temperatures rise during the day to temperatures that are really negligible. On average, I recall, it's something liek 0.6 degrees celcius in the last 100 years and this is not much different to temperature changes throughout history. However, the problem is that we've seen massive increases in minimum temperatures. So 40,000 years ago, or whatever, it would be 31 during the day and then 12 (or whatever) during the night. Now it's more like 31 at day and 26 at night... That's going to cause a big problem in the next 100 years if the trend in temperature increases continues...

You're a shitty troll, so stop pretending you have more of a life than a cool dude -- HollyHopDrive
[ Parent ]

Huh (3.00 / 3) (#56)
by pHatidic on Thu Apr 07, 2005 at 09:10:23 PM EST

As a scientist, you should know that just because you haven't heard it, doesn't mean it's not a factual supposition.

That's why I voted the article down, because there was no support for the claims.

[ Parent ]

unsubstantiated assertions considered harmful (none / 0) (#58)
by jsnow on Thu Apr 07, 2005 at 11:03:18 PM EST

As a scientist, you should know that just because you haven't heard it, doesn't mean it's not a factual supposition.

No, a scientist should know that if someone makes a large number of unsubstantiated assertions, they're probably a) talking about something they don't know anything about, b) trying to deliberately mislead people, or c) too lazy to check if the "facts" they heard or read somewhere are credible or not.

[ Parent ]

You've never heard of methane hydrates? (none / 0) (#79)
by Russell Dovey on Fri Apr 08, 2005 at 07:56:55 AM EST

Is your school one of those ones in Kentucky where science is part of "Satan's plan for us all" 101?

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

I was (none / 0) (#97)
by Sgt York on Fri Apr 08, 2005 at 11:26:03 AM EST

Wondering about that, too. I'm not in environmental science, but I know a bit about how life works. When I read that statement, my first thought was "Hm. I've never heard that before", which was quickly followed by "What the hell is the mechanism behind that?"

I was thinking perhaps the C4 thing...I can't recall the exact name, but where plants lose some of the fixed carbon during the dark reactions. C4 plants like corn have structural changes that keep it in check....I'm not a botanist, though.

Does anyone know what this is about? References?

There is a reason for everything. Sometimes, that reason just sucks.
[ Parent ]

I like it (2.90 / 10) (#44)
by BobTheMighty on Thu Apr 07, 2005 at 06:23:12 PM EST

Solutions to any problem that involve a gigantic orbital something should be advanced just on general principle.
-
I'll try not to confuse you more than absolutely necessary
Yawn. (1.11 / 9) (#45)
by pestilence on Thu Apr 07, 2005 at 06:48:23 PM EST

More bogus hack "science". -1


A documented gay hook-up
Yeah.. (none / 0) (#93)
by ajduk on Fri Apr 08, 2005 at 11:03:29 AM EST

'Imagination', 'Speculation', 'Inventiveness'; what has it ever done for us?

[ Parent ]

Numerous genocides. (none / 1) (#183)
by pestilence on Sat Apr 09, 2005 at 08:44:58 PM EST




A documented gay hook-up
[ Parent ]
Easier solution (1.68 / 16) (#48)
by balsamic vinigga on Thu Apr 07, 2005 at 07:08:58 PM EST

We need to cool things down right?  Well, I'm a pretty cool son of a bitch.  Cooler than Freddy Jackson sippin a milkshake in a snowstorm, if you will.  So, what we need to do is round up all the cool bitches on the planet and have me impregnate them with my seed, to insure that more cool ass sons a bitches like myself are born to chill things out a lil.

If my cool ass can impregnate one cool chick a day for the next 25 years, we will have enough cool-as-all-hell babies to counteract the effects of global warming.

Currently I bust a rather large load 3 or 4 times a day, so I'd say those numbers are quite obtainable.  And in just 15 years or so my cool ass offspring can continue to chill things down by making me some cool ass grand children.

---
Please help fund a Filipino Horror Movie. It's been in limbo since 2007 due to lack of funding. Please donate today!

You're cool as ice. (2.50 / 6) (#66)
by pwhysall on Fri Apr 08, 2005 at 03:02:50 AM EST

Vanilla Ice.
--
Peter
K5 Editors
I'm going to wager that the story keeps getting dumped because it is a steaming pile of badly formatted fool-meme.
CheeseBurgerBrown
[ Parent ]
Calm down - or you might go blind. (n/t) (none / 0) (#128)
by werebear on Fri Apr 08, 2005 at 04:57:20 PM EST



[ Parent ]
This interview says $200 B; Science says 2000 km. (3.00 / 4) (#59)
by Another Scott on Thu Apr 07, 2005 at 11:24:48 PM EST

SciFi.com:

gb:For example. I serve on a Dept Energy review panel, and we looked at a proposal to solve the whole global warming problem by refracting away sunlight, using a thin lens a million miles out, at the L1 spot--and to do so would cost $2 b00 billion--peanuts.

gb:oops-- 200 billion bucks

It's not clear whether that's a total budget including operating costs or not. But what's a factor of 10 among friends?

This paper in Science (with Benford as a coauthor) talks about various strategies for controlling the rate of global warming. It says:

Space-based geoengineering. The Lagrange interior point L1 provides an opportunity for radiative forcing to oppose global warming. A 2000-km-diameter parasol near L1 could deflect 2% of incident sunlight, as could aerosols with engineered optical properties injected in the stratosphere.

What's a factor of 2 among friends?

The point? You should cite the sources for your numbers as Benford seems to have changed his values over time (if your summary is correct).

Cheers,
Scott.

Thanks, I was looking for confirming numbers, (none / 0) (#69)
by Russell Dovey on Fri Apr 08, 2005 at 04:21:14 AM EST

I did wonder if he'd changed his mind. Thanks.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

And made from lunar glass! Awesome. (none / 0) (#70)
by Russell Dovey on Fri Apr 08, 2005 at 04:37:43 AM EST

Okay, so he's refined the idea to a mirror, not a lens, made from glass not plastic, made it 2000 kilometres across not 1000, and sourced from the moon, not an asteroid.

How much cooler is a giant glass mirror? Supervillains everywhere thank Benford for his sacrifice. (There's always sacrifice.)

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

Political Problems (none / 1) (#67)
by se71 on Fri Apr 08, 2005 at 03:58:14 AM EST

This sounds like a nice project, but the administration and politics would kill it if it was ever attempted.

How can one country or group of countries block out light from the sun to every single person on the planet?

I also pessimistically see it working too well, and turning on an ice-age.

This is defintely a last resort option for when things are already intolerable.

Prior art... (none / 0) (#71)
by JohnLamar on Fri Apr 08, 2005 at 04:47:32 AM EST

...this idea was totally ripped off of the Simpsons.
The worst thing you've ever seen
[ Parent ]
and when it breaks.... (none / 1) (#76)
by m a r c on Fri Apr 08, 2005 at 07:43:40 AM EST

ok so if we do have this space lens set up, what is going to happen if some asteroid hits it or something? How bout we make the survival of our entire planet contingent on some fragile piece of technology millions of miles away, yeah, great idea. And on the more stupid side, when space aliens come all they will need to do is smash the lens and watch us cook.
I got a dog and named him "Stay". Now, I go "Come here, Stay!". After a while, the dog went insane and wouldn't move at all.
If we see an asteroid coming for it... (none / 0) (#80)
by Russell Dovey on Fri Apr 08, 2005 at 07:59:27 AM EST

...which has a lower probability even than one hitting us, then we'll have to move it out of the way with the station-keeping thrusters, or simply let it go through, make a kilometer-sized hole or whatever, and unroll more plastic over the top.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

Errm.. (none / 0) (#92)
by ajduk on Fri Apr 08, 2005 at 11:01:43 AM EST

The earth is lucky to have an atmosphere to stop the vast majority of space rocks. This structure does not. It would get hit a LOT, and it's about a fragile a structure as possible.

[ Parent ]

Would *NOT* get hit a lot (none / 0) (#166)
by badtux on Sat Apr 09, 2005 at 12:55:21 AM EST

Any debris in that orbit is not moving very fast in relation to point L1. Any debris *NOT* in that orbit (i.e., in an elliptical orbit that intersects that orbit at high speed more than once every few centuries) has been swept up by the Earth billions of years before because its orbit would intersect Earth orbit. Most of the "meteor showers" that you see from time to time on Earth are actually chunks of rocks that were swept up by the Earth millions of years ago, that are just taking this long an amount of time to de-orbit and burn up in the atmosphere.

Now, granted, there is debris on elliptical orbits intersecting L1 that has NOT been swept up by the Earth over the millenia, but there's not much of it. A far bigger problem will be dust particles pushed out of lower orbit via photonic pressure and energetic particles from the sun causing surface erosion, thus gradually turning it into a solar sail rather than a light redirector. But there isn't that much dust at L1 either, which is why we have a solar observatory sitting there -- it's a nice clean place to watch the sun from (or block the sun, if we so desire).

In other words, there's practical problems here, such as the number of rocket launchers that would be needed, the materials science and aerospace engineering needed to build a flexible fresnel lense of this nature such that it could be deployed in an automated fashion outside of Earth orbit (because we can't get people up there to do it), etc. but they are unrelated to space junk. Most of the space junk in the neighborhood is sitting in Earth orbit and we put it there.

Badtux the Orbital Penguin
In a time of chimpanzees, I was a penguin
[ Parent ]

Uh, the lens is silly but that's not the reason (none / 0) (#94)
by Anonymous Hiro on Fri Apr 08, 2005 at 11:09:33 AM EST

If an asteroid hits it once, it's no big deal. We won't fry (unless some freak incident causes the lens to magically focus and not diffuse).

After all, we'd just be exposed to the sun directly as normal.

That said, I think like another poster suggested: we should just put something smaller but opaque in front of the sun. That would block off x% of the Sun, and still leave the full spectrum through past the unblocked parts.

Don't see why it has to be transparent and thin. Just some reflective mylar or other reflective opaque fabric will do. No need to focus.

I suggest a spinning triangle: put mass on the points of the triangle, tether the points to each other, attach the mylar to the tethers and spin it from there. Even if the mylar isn't stretched out it doesn't matter.

To control the amount of sunlight blocked you just tilt the triangle.

You could put transparent cutouts in the mylar for advertising ;). That might help pay for it.

[ Parent ]

Haha... (none / 0) (#120)
by JahToasted on Fri Apr 08, 2005 at 03:35:38 PM EST

You could put transparent cutouts in the mylar for advertising ;). That might help pay for it.

I can see it now... "This permanent eye damage has been brought to you by Coca cola".
______
"I wanna have my kicks before the whole shithouse goes up in flames" -- Jim Morrison
[ Parent ]

Photonic pressure (none / 0) (#164)
by badtux on Sat Apr 09, 2005 at 12:46:23 AM EST

If it reflects light, rather than simply redirecting it, then photonic pressure will turn it into a very large sail and it'll soar right out of the solar system. If it absorbs light rather than reflecting it, it will swiftly heat up to the point where it either melts or starts glowing and thus radiating the heat as infrared or visible light, at which point the emitted photons again end up pushing it off to the nether regions of the solar system. Thus if it is not to be a giant light sail, it has to be transparent and merely redirect the light, not stop it. Or else it has to have enormous mass, so much mass that photonic pressure won't move it, but we don't have the ability to put that much mass at the L1 point.

- Badtux the Space Penguin
In a time of chimpanzees, I was a penguin
[ Parent ]

smoke and mirrors (none / 1) (#179)
by proletariat on Sat Apr 09, 2005 at 11:47:02 AM EST

How about putting a cloud of smoke between us and the sun? It could spread very quickly in the vacuum of space to the point where it's not visible but provides some protection. It could be replenished from time to time and could dissipate by the time we solve our CO2 emmission problems. I guess a little too much could tip the earth into an ice age though. Maybe if the price of oil goes high enough that will solve the problem for us.

[ Parent ]
Enviro-wackos.. (1.25 / 4) (#78)
by The Amazing Idiot on Fri Apr 08, 2005 at 07:56:31 AM EST

They say the darndest things, yet we cant get an accurate 5 day forecast on weather.

What makes it that they know what happens 50-100 years?

I say BLEH to them all.

You are calling people whackos (none / 0) (#83)
by brain in a jar on Fri Apr 08, 2005 at 09:08:10 AM EST

yet you are trying to take part in a climate debate, without an understanding of the difference between weather and climate...


Life is too important, to be taken entirely seriously.
[ Parent ]

Better keep your mouth shut... (none / 0) (#86)
by coopex on Fri Apr 08, 2005 at 10:27:12 AM EST

and be thought a fool than to open it and remove all doubt. weath·er ( P ) Pronunciation Key (wthr) n. The state of the atmosphere at a given time and place, with respect to variables such as temperature, moisture, wind velocity, and barometric pressure. cli·mate ( P ) Pronunciation Key (klmt) n. The meteorological conditions, including temperature, precipitation, and wind, that characteristically prevail in a particular region. me·te·or·ol·o·gy ( P ) Pronunciation Key (mt--rl-j) n. The science that deals with the phenomena of the atmosphere, especially weather and weather conditions. So, from these definitions, it seems pretty clear that weather and climate refer to the same thing, and you're the one who doesn't have a clue what you're talking about.

[ Parent ]
Oh dear.. (3.00 / 2) (#91)
by ajduk on Fri Apr 08, 2005 at 10:55:35 AM EST

Let's go through this slowly and simply..

Starting with definition 1):

Weather: The state of the atmosphere at a given time and place, with respect to variables such as temperature, moisture, wind velocity, and barometric pressure.

Now, what this is essentially saying - and the phrase 'given time and place' is a bit of a giveaway; the 'weather' refers to a snapshot of current conditions.

Climate: The meteorological conditions, including temperature, precipitation, and wind, that characteristically prevail in a particular region.

Now here you may notice the phrase 'characteristically prevail'. What this means in scientific terms is that the climate for a given reason is a stastical average of the weather, and this is not the same thing.

To try an illustrate this in simple terms, try rolling a die many times. You will get random numbers between 1 and 6 - and you cannot predict what you'll get in advance. Call this 'Weather'. However, if you add up the numbers you get and divide by the number of throws, you'll get 3.5 - and you CAN predict this. This is 'Climate'.

So, even if you can't predict a specific event, you can predict the average of such events. Amazing stuff, this maths thingie, isn't it? So, weather and climate are not the same thing, and we can predict climate without being able to predict weather.

[ Parent ]

My bad (none / 0) (#104)
by coopex on Fri Apr 08, 2005 at 12:24:26 PM EST

Good point about climate being the average of weather. Getting back to the orginal poster's post, the only way we know how to predict the climate is by averaging all the weather data, so if we can't accurately predict 5 days into the future it is, as The Amazing Idiot said, whacko to think we can predict the climate 50 years from now.

[ Parent ]
Not that crazy (none / 0) (#119)
by Polverone on Fri Apr 08, 2005 at 03:00:09 PM EST

I can't predict the exact sort of weather we'll see in my town on February 1, 2006, or on July 1, 2006, but I can make general predictions about the differences we'll see between those days. I can't predict specifically if you'll get in a car accident 5 years from now, but I can make reasonable predictions about car accidents in general 5 years from now. Even in abstract chaotic mathematical systems, I can find boundaries and average behaviors in different regions. It's not necessary to predict specifics to produce a good prediction of generalities. This is not a guarantee that current global warming predictions are correct, but the objection "we can't even predict the weather a year from now!" is not really relevant to whether or not the predictions are reasonable.
--
It's not a just, good idea; it's the law.
[ Parent ]
But that misses the whole point! (none / 0) (#124)
by coopex on Fri Apr 08, 2005 at 04:10:10 PM EST

Yes, I agree that winter in chicago in January will usually be around 10 degrees, and in July it'll be around 80 degrees, and that we can give general estimates of many things like weather and car crashes.  However, this does nothing to support or discredit global warming because it is far too vague to be a useful scientific measure.


[ Parent ]
Try this (none / 0) (#123)
by 5inay on Fri Apr 08, 2005 at 04:08:04 PM EST

If rand() returns either +1 or -1 with equal probablity, you can't predict what the nth value is going to be, but you know pretty well that the average is going to be 0 with high probability.

[ Parent ]
Your comment has no relevance (none / 0) (#150)
by coopex on Fri Apr 08, 2005 at 11:22:01 PM EST

Sure, if we know the probability distribution, as in the case of dice or your rand() function, we can find the average. The part you're missing is that we don't know the probability distribution of the weather, so most all claims about predictions of the climate are 99% political BS and 1% science, with a margin of error of +/- 1%.

[ Parent ]
Climate, weather, averages.. Gah. (none / 1) (#168)
by The Amazing Idiot on Sat Apr 09, 2005 at 01:09:25 AM EST

Well, even since Lorentz's equasions have been somewhat expanded (from his original 3 days to about a week), and the advent of ensemble prediction (make a tree of top X possible events, and average em together), gives a somewhat decent forecast.

Still, unless you monitor every cubic centimeter of space all around the earth, the equasions WILL break down rapidly due to chaotic fluctuations in the earth, weather patterns, Sun radiation patterns, and everything possible that's not currently measured.

And like I said, forecasters cant even give a 100% success rate for the next day, let alone a week. Why in the hell should we believe some nut who says THEY can predict years and years and years?

Sounds like utter bullshit to me.

[ Parent ]

You still don't get it.. (none / 0) (#219)
by ajduk on Mon Apr 11, 2005 at 04:51:06 AM EST

You are still confusing the issues. To extend the analogy further, you seem to be thinking that the only way to model a die roll is to roll it lots of times and average out the results. This is the wrong way around - you can construct a model without a single roll, and then test it by rolling the die.

As far as climate goes, people were constructing 1D models even before computers were commonly used, and these are surprisingly accurate at PREDICTING global average temperature. This being prior to the phrase 'Global Warming' even existing. Apparently you think this couldn't be done; you are wrong.

[ Parent ]

I'm interested (none / 0) (#222)
by coopex on Mon Apr 11, 2005 at 07:57:46 AM EST

Do you have links or references to back that statement up?

[ Parent ]
Yes. (none / 0) (#229)
by ajduk on Mon Apr 11, 2005 at 09:59:45 AM EST

You might not believe it, but sometimes scientists take time off from making up end-of-the-world scenarios just to get more government grants and occasionally do unbiased, honest work.

This gives a basic intro.

[ Parent ]

Thanks for the chuckle.... (1.75 / 4) (#81)
by carpsioUK on Fri Apr 08, 2005 at 08:35:22 AM EST

This is one of the silliest things I have read for a good while. It smacks completely of those 1950's "by the year 2000 man will have mated with moles enabling him to live underground to shelter from the effects of the impending nuclear winter..." pieces of futurism.

No-one has ever, or will ever, build this lens, for all its gee-whizz appeal. It is typical of what happens when a theorist really goes to town. "It will only cost 6p, will save the world, and yet governments are too blinkered/tight/evil to fund it..."

Poppycock. It won't happen because the engineering challenges are too vast, the results too improbable, the chance of failure too great. A single piece of unremarkable rock tumbling through the void at the right trajectory could end the whole enterprise in a couple of microseconds.

Let alone the sad fact that "climate change" is neither exclusively down to human activity, or ultimately preventable anyway. The climate is, pretty much by definition, always in a state of change. Examine any two points on a graph of the world's temperature, and it is is always either getting warmer or cooler.

We have no idea how the carbon exchange between the oceans and the atmosphere works... no real knowledge of whether carbon dioxide is as big an agent in climate as water vapour... what the effect of the changing albedo of the Earth is... no real idea what has caused abrupt warmings and coolings in the past. We don't even have a reliable figure for the average land temperature of the Earth 70 years ago.

Not that I expect this to fall on anything except deaf ears. We seem to be too far into this millenial panic to seperate facts from politics...


--------------------- CARPS
Nope, the rock won't hurt anything (none / 0) (#162)
by badtux on Sat Apr 09, 2005 at 12:40:31 AM EST

Fresnel lenses continue working with holes in them. Try it yourself sometimes. Get one of those plastic "magnifier" sheets (like what used to be sold to put over computer monitors, back in the day when computer monitors were 12 inches wide). Cut a hole in it with a hot knife. The remainder of it is still magnifying!

In other words, your hypothetical rock (which is hypothetical because anything in that orbit is moving very slowly in relation to L1, and anything fast-moving in an eliptical orbit that crosses that orbit regularly would have been swept up by the Earth or Moon a billion years ago) will put a small hole in the thing, but will only degrade it slightly, not destroy it.

- Badtux the Orbit-computing Penguin
In a time of chimpanzees, I was a penguin
[ Parent ]

Err... (none / 0) (#353)
by beergut on Wed Apr 27, 2005 at 03:28:57 PM EST

What if the rock hit the "lens" edge-on?

Presumably, this lens is a more or less coherent structure (otherwise, its spinning to maintain shape in the face of photon pressure would cause it to fly rather spectacularly apart).

What happens if a rock hits it then? My guess is that it would carry the lens with it on a slightly altered trajectory, and that would be the end of that.

i don't see any nanorobots or jet engines or laser holography or orbiting death satellites.
i just see some orangutan throwing code-feces at a computer screen.

-- indubitable
[ Parent ]

nice thought... (none / 0) (#360)
by masher on Fri Apr 29, 2005 at 02:35:10 AM EST

...but the end result would be no different.  For an object 1000km across and a a few micrometers in thickness, it essentially has no "edge" to hit.  

Assume a 10 meter diameter rock strikes the lens at a right angle...the best case scenario.  It punches a 10m hole obviously.  Now, imagine it striking at VERY near edge on (89.99 degrees, or within 0.01 degrees of exactly on edge).  That would punch a hole of size 10m + thickness*tan(89.999).  Assuming the lens was 100um thick, that'd add an extra 5.7m to the size of the hole...not a big difference.  

[ Parent ]

And if... (none / 0) (#362)
by beergut on Mon May 02, 2005 at 03:57:49 PM EST

A large-ish rock hit the edge of the lens at 90.0000 degrees?

i don't see any nanorobots or jet engines or laser holography or orbiting death satellites.
i just see some orangutan throwing code-feces at a computer screen.

-- indubitable
[ Parent ]

The point? (none / 0) (#363)
by masher on Mon May 02, 2005 at 04:42:10 PM EST

A large-ish rock hit the edge of the lens at 90.0000 degrees?

Worst case scenario is a travel path long enough to destroy structural integrity...in which case the centripedal acceleration of the lens would cause it to tear itself apart. I think quite obviously, the outer rim would be designed in such a way as to deflect upon impact. But a significantly large mass wouldn't be affected.

Now, ask yourself what are the odds of a very massive rock not only striking this lens in the next few centuries....but doing so at exactly a 90.0000 degree angle? You might as well bet on a comet striking the earth and destroying all life on the planet. Space is mostly empty. The earth gets hit with a lot of junk. But the earth is far larger; it has gravity to increase the chances of a strike...and nearly all that junk is small enough to be harmless to such a lens assembly anyway.

[ Parent ]
The question... (none / 0) (#364)
by beergut on Tue May 03, 2005 at 11:08:07 AM EST

... was not one of probability, but "what if".

If they build the lens with enough structural integrity to withstand fairly rapid rotation, then it might withstand a collision with a rock, at least to the point of being carried away or at least torn asunder.

i don't see any nanorobots or jet engines or laser holography or orbiting death satellites.
i just see some orangutan throwing code-feces at a computer screen.

-- indubitable
[ Parent ]

Can't do it (none / 0) (#365)
by masher on Tue May 03, 2005 at 12:59:28 PM EST

If they build the lens with enough structural integrity to withstand fairly rapid rotation, then it might withstand a collision with a rock...

No, the force from centripedal acceleration is only to stabilize the structure...it actually lets you build a thinner, weaker structure by putting a low spin on it.

Even if we wanted to build it tough enough to stop a large asteroid, we couldn't. You've got to assume a velocity of 30-50 km per SECOND. For a rock from the outer solar system on a highly elliptic orbit, it could be twice that or more. Even if we made it a hundred times thicker and used titanium instead of plastic, it's a lost cause. You don't design it to withstand the impact....you design it to fail gracefully.

[ Parent ]
Solution for two problems (none / 0) (#84)
by michaelp on Fri Apr 08, 2005 at 09:44:14 AM EST

  1. reduce global warming
  2. gather some of the sunlight and beam it to Earth.
With space based solar power, we'd have all the energy we'd ever need from a clean source, very little pollution (just from manufacturing rectennas), very little waste, and virtually no limit.

And no more need to conquer small countries with large oil reserves---wait that's 3! woo hoo!

"Every gun that is made, every warship launched, every rocket fired, signifies in the final sense a theft from those who hunger and are not fed, those who are cold and are not clothed."

The $400 billion dollar question... (none / 0) (#144)
by smithmc on Fri Apr 08, 2005 at 09:11:35 PM EST


And no more need to conquer small countries with large oil reserves---wait that's 3! woo hoo!

But... but what will we do with that $400 billion we spend on "defense" every year? Think of all the soldiers and contractors that will be out of work! Think of how the scrap steel market will be depressed when we tear up all those carriers and subs! Think of all the young men and women who won't get to travel to far and exotic lands, meet new and interesting people, and kill them! Oh, duh howwuh! Duh howwwwuh!

[ Parent ]

that's easy (none / 0) (#155)
by QuantumG on Sat Apr 09, 2005 at 12:15:44 AM EST

Militarize space. Two birds, one stone.

Gun fire is the sound of freedom.
[ Parent ]
Well (none / 0) (#159)
by michaelp on Sat Apr 09, 2005 at 12:32:37 AM EST

if the US had control of the global warming sheild/solar power satellite, it would help with point to point regime change...

"Aiieee! A beam of concentrated sunlight just burned the Great Leader's armored car to a crisp!!!?? Hoo well, maybe we better try that democracy thing..."

"Every gun that is made, every warship launched, every rocket fired, signifies in the final sense a theft from those who hunger and are not fed, those who are cold and are not clothed."

[ Parent ]

Or ... (none / 0) (#190)
by mrt on Sun Apr 10, 2005 at 01:48:08 AM EST

Aiieee! A beam of concentrated sunlight just burned the democratically elected socialist government to a crisp!!! Better smoke some more Malborough's and eat some burgers we can't afford.
-

I'd give my right arm to be ambidextrous
[ Parent ]
In a world where power is plentiful and cheap (none / 0) (#201)
by michaelp on Sun Apr 10, 2005 at 12:01:34 PM EST

things like 'socialists' and 'free marketeers' would be pretty much obsolete.

All the current political/economic systems are based on a scarcity of resources, what if there were no more scarcities?

"Every gun that is made, every warship launched, every rocket fired, signifies in the final sense a theft from those who hunger and are not fed, those who are cold and are not clothed."

[ Parent ]

always are scarcities (none / 0) (#218)
by khallow on Mon Apr 11, 2005 at 04:46:32 AM EST

In a land of plenty, you'll still have sexual dominance/competition games. Someone will create artificial scarcities for this purpose. It already occurs with such things as branded makeup or designer clothes.

Stating the obvious since 1969.
[ Parent ]

The tipping point. (none / 0) (#220)
by mrt on Mon Apr 11, 2005 at 07:12:53 AM EST

The agricultural, industrial and technological revolutions were all accompanied by an increase in the population.

Soooo ... the demand increased to fill the supply.

This human behaviour (of ever increasing population) only has three practical limits.

1. Supply of trace minerals.
2. Availability of land.
3. Maximum birth rate.

Since the MOST limited of those three limits is 3.Maximum birth rate, we would first need more energy than births, for the population increase to be a constant.

That is, if the fastest a human female can practically reproduce is every year for 10 years, and the average age at which this begins is age 16, then we know that every 26 years, then population of the world will increase approximately four-fold.

Extrapolating that into the future, we arrive at the following numbers for future global population.

2031 - 28 billion
2057 - 102 billion
2083 - 408 billion
2109 - 1.2 trillion people

I think before 2109 we would reach limit number 1. Availability of trace minerals. We could always mine minerals from the moon.

So following your utopian dream of abundant, cheap energy, we can suppose that there would be a massive global war (over access to trace minerals) sometime between 2083 and 2109, killing roughly 40-120 billion people (decimating the population) . Then we would settle back into another steady state of war-reproduce-war.



-

I'd give my right arm to be ambidextrous
[ Parent ]
Whoa (none / 0) (#227)
by tetsuwan on Mon Apr 11, 2005 at 09:10:17 AM EST

In your calculations, where do you compensate for the fact that reduced scarcity of food brings about a reduced birth rate? Check your stats - all developed countries except the US have birth rates that don't really match up with the death rates - especially Italy and Japan.

Njal's Saga: Just like Romeo & Juliet without the romance
[ Parent ]

Hmmm ..... (none / 0) (#258)
by mrt on Tue Apr 12, 2005 at 06:08:47 AM EST

In your calculations, where do you compensate for the fact that reduced scarcity of food brings about a reduced birth rate?

Actually, I was talking about energy, not food. Availability of food is only one factor in the birth rate.
My calculations were based on an ever increasing supply (at an ever decreasing cost) of energy.

Check your stats - all developed countries except the US have birth rates that don't really match up with the death rates - especially Italy and Japan.

Yes. But those countries are paying more for energy now (in real terms) than they were ~90 years ago. In fact, for the first ~70 or so years of the current energy revolution, energy became cheaper each year in real terms, and there was a corresponding increase in the birth rate.

However, in the last ~30 years, energy has increased in price each year in real terms, and there has been a corresponding decrease in the birth rate.

If, through some miracle of science or serendipity, we were to discover an energy source that decreased in price and increased in availability on a continuous basis, then we would see an increase in the birth rate all over the world, including the West.


-

I'd give my right arm to be ambidextrous
[ Parent ]
That's an oversimplification, to say the least (none / 0) (#261)
by tetsuwan on Tue Apr 12, 2005 at 10:37:31 AM EST

What about the nonexistent population boom in Norway (oil + hydropower) or Iceland (geopower)?

Go read some social sciences. You clearly have no idea why people in the rich world have few children.

Njal's Saga: Just like Romeo & Juliet without the romance
[ Parent ]

You win ... (none / 0) (#270)
by mrt on Wed Apr 13, 2005 at 05:29:40 AM EST

Go read some social sciences. You clearly have no idea why people in the rich world have few children. I clearly don't. I assume it has nothing to do with lack of time or energy to fornicate.
-

I'd give my right arm to be ambidextrous
[ Parent ]
Ever heard of birth control? (none / 0) (#274)
by tetsuwan on Wed Apr 13, 2005 at 12:33:15 PM EST

*sigh*

Njal's Saga: Just like Romeo & Juliet without the romance
[ Parent ]

Post hoc fallacy (none / 0) (#268)
by michaelp on Wed Apr 13, 2005 at 02:05:02 AM EST

The reduction in birth rate is not connected to energy cots rather the birth rate reduction in modern societies appears to be due to women being able to have careers and control their reproduction.

Strangely, when given a choice, many women choose not to have a child every year from the time they are 16 to the time they hit menopause.

Many women choose not to have a child at all in societies where they are given a choice.

This leads to a general reduction in birth rate, and there is no indication that lower energy bills would cause many women to change their minds--childbirth is a long, painful, and somewhat dangerous process even with lots of applicances running all the time.


"Every gun that is made, every warship launched, every rocket fired, signifies in the final sense a theft from those who hunger and are not fed, those who are cold and are not clothed."

[ Parent ]

What percentage. (none / 0) (#271)
by mrt on Wed Apr 13, 2005 at 05:36:29 AM EST

Strangely, when given a choice, many women choose not to have a child every year from the time they are 16 to the time they hit menopause.

Women hit menopause at 26? I here I was thinking that it was later than that .... hmmm ... I better catch up with the latest research.

The reduction in birth rate is not connected to energy cots rather the birth rate reduction in modern societies appears to be due to women being able to have careers and control their reproduction.

If the energy cost was near zero, why would they need a career?
If the cost of raising children was near zero, would that still be the case?

Many women choose not to have a child at all in societies where they are given a choice.

Give me a percentage of the female population that this applies to.
Do these women pass this behaviour on to their non-existent children?

childbirth is a long, painful, and somewhat dangerous process

Does it have to be?

-

I'd give my right arm to be ambidextrous
[ Parent ]
Where are you getting your data? (none / 0) (#277)
by michaelp on Wed Apr 13, 2005 at 10:20:53 PM EST

regarding the relationship between energy cost and birthrate?

In fact a feature in most societies where birth rate has dropped is a reduciton in real cost of energy, e.g. pumping oil vs. cutting and hauling wood.

Women hit menopause at 26?

What petty point are you making here and was it worth making? Women stop having children after the tenth? Of course in societies where energy costs are high, there tend to be more miscarriages...

Give me a percentage of the female population that this applies to.

In the US it's ~20%.

Do these women pass this behaviour on to their non-existent children?

What is your point?

Does it have to be?

Yes, with current technology (and anything likely to be implemented on a wide scale by the date of your dystopia). Even if we invent some way to raise children are raised in creches and signigicant numbers of people start using it, your 'point' regardin using up 'trace minerals' is even more non-existent, obviously (but can you grasp why all on your own, that is the interesting question...)  

"Every gun that is made, every warship launched, every rocket fired, signifies in the final sense a theft from those who hunger and are not fed, those who are cold and are not clothed."

[ Parent ]

Where are you getting yours? (none / 0) (#284)
by mrt on Fri Apr 15, 2005 at 05:36:11 AM EST

In fact a feature in most societies where birth rate has dropped is a reduciton in real cost of energy, e.g. pumping oil vs. cutting and hauling wood.

My data is based on the price of oil from 1904 to 1974, and the birthrate in the USA (and Australia) in that period, versus the price of oil (in real terms) and the birth rate from 1974 to the present.
The most accessable source of the price of oil is Paul Hawken's 'The Next Economy'. As for the birth rate, it is freely available from government statistics.

Now tell me where you are getting YOUR data which invalidates my conclusion.

Women stop having children after the tenth?

Yes, I believe that there is probably a biological limitation that averages out at ten. You call my point petty, but fail to acknowledge your underhanded attempt to put words into my mouth.

In the US it's ~20%.
20% of women in the US die without giving birth? Really? Can you point me to the source of that figure so I can research it myself?
Does your source also say how many of those women are unable to concieve (i.e. infertile)?

What is your point?
My point is that this behaviour may have been 'learned' from their mothers, but it certainly won't be 'taught' to their daughters.


Yes, with current technology (and anything likely to be implemented on a wide scale by the date of your dystopia)

I disagree, but the point is almost certainly moot. The status quo is ipso facto, and the future is merely speculation.

your 'point' regardin using up 'trace minerals' is even more non-existent, obviously (but can you grasp why all on your own, that is the interesting question...)

Perhaps my stupidity is only exceeded by your laziness? Can you prove me wrong and offer up your reposte?


-

I'd give my right arm to be ambidextrous
[ Parent ]
As we established in the other thread (none / 0) (#332)
by michaelp on Wed Apr 20, 2005 at 03:38:22 PM EST

you didn't even know the definition of "trace minerals" before you started rambling on about their effect on maximum human population.

The "price of oil" is not the "price of energy". You need to look at the total price of all energy, and also look at the price of energy in terms of per capita income to start making sense. Hint, if the "real price" of oil rises but the "real income" also rises then the amount buying oil takes away from a person's income falls.

As has been pointed out elsewhere, there are countries where the price of energy has fallen or remained constant, and birthrate has been falling, falsifying your point even if you lack a basic understandng of logic. Conversly, there are plenty of countries where the cost (%per capita income) is very high and rising, and yet the birth rate is also rising.

"Every gun that is made, every warship launched, every rocket fired, signifies in the final sense a theft from those who hunger and are not fed, those who are cold and are not clothed."

[ Parent ]

Only if... (none / 0) (#352)
by beergut on Wed Apr 27, 2005 at 03:17:23 PM EST

They don't have the machine that goes "Ping!"

i don't see any nanorobots or jet engines or laser holography or orbiting death satellites.
i just see some orangutan throwing code-feces at a computer screen.

-- indubitable
[ Parent ]

You stopped making sense (none / 0) (#266)
by michaelp on Wed Apr 13, 2005 at 01:50:03 AM EST

when you failed to follow your own thread:

We could always mine minerals from the moon.

The solar system is full of trace minerals. With unlimited energy there is no reason we can't get support 10s or even hundreds of trillions of human beings...in spaaaace.

The main limit you've demonstrated is one of imagination:-).

"Every gun that is made, every warship launched, every rocket fired, signifies in the final sense a theft from those who hunger and are not fed, those who are cold and are not clothed."

[ Parent ]

I had two threads to follow, so .... (none / 0) (#273)
by mrt on Wed Apr 13, 2005 at 05:57:26 AM EST

The solar system is full of trace minerals. With unlimited energy there is no reason we can't get support 10s or even hundreds of trillions of human beings...in spaaaace.

Assuming that we are able to travel beyond the solar system to other planet bearing systems and back in less time than it takes to consume all of the trace minerals in our own solar system.

My recollection is that Alpha Centuri has no planets, and the closet planet bearing system is approx 200 light years distant. (If you have information to the contrary, please share.)

At near light travel, it would still take more than 400 years to return with each load of trace minerals. (let's call it 500 years)

If 500 years is adequate, then you are correct, the population can probably expand indefinitely. If not, we probably just delayed the Trace Mineral War for another 250-500 years.

Of course, there is the possibility that we discover a planetary system capable of sustaining human life in some distant star system. There might be a problem moving 1.2 trillion people there before the population quadruples again.


-

I'd give my right arm to be ambidextrous
[ Parent ]
What evidence do you have that (none / 0) (#278)
by michaelp on Wed Apr 13, 2005 at 11:16:54 PM EST

a: there are not enough of these 'trace minerals' in the solar system for trillions of people for thousands of years?

Remember that Earth is one of the smaller planets:-).

b: don't you think it's kind of silly to think that we will need to go to other solar systems to get trace minerals when simpler technology would allow us to make them?

After all, all we need is a little fusion and some atoms to make all the 'trace minerals' we could ever  need. You don't think we are going to run out of protons, electrons, and neutrons anytime soon, do you?

By the way, you do realize they are called 'trace minerals' because we need very little of them, not because they are rare?

Remember, Sid Meier is a game author and Civ is a game, not a simulation of the real world...

"Every gun that is made, every warship launched, every rocket fired, signifies in the final sense a theft from those who hunger and are not fed, those who are cold and are not clothed."

[ Parent ]

In reply ... (none / 0) (#285)
by mrt on Fri Apr 15, 2005 at 05:56:35 AM EST

a: there are not enough of these 'trace minerals' in the solar system for trillions of people for thousands of years?

None. But I don't have any evidence for the other posibility either, that there are plenty of trace minerals on the other planets.
Presumably, Voyager and the Mars rover have been doing some kind of spectroscopy(sp?) to determine the mineral composition of Mars and Jupiter's rings, but I don't know what they found.

I curious to know how you know that the other planets contain large amounts of trace minerals.

After all, all we need is a little fusion and some atoms to make all the 'trace minerals' we could ever need. You don't think we are going to run out of protons, electrons, and neutrons anytime soon, do you?

I wasn't thinking of introducing large amounts of caesium-137 or strontium-90 in my diet, but if that's what it takes .....

By the way, you do realize they are called 'trace minerals' because we need very little of them, not because they are rare?

Do you mean that there is exactly the same amount of each element in the universe? I wonder why there are more sand mines than uranium mines then. Hmmm...

Remember, Sid Meier is a game author

Who?
-

I'd give my right arm to be ambidextrous
[ Parent ]
No (none / 0) (#294)
by michaelp on Fri Apr 15, 2005 at 08:15:52 PM EST

Do you mean that there is exactly the same amount of each element in the universe?

I mean "trace minerals" are common, even on Earth. They are 'trace' in our bodies not in the environment. Which makes your concern over running out of them as some sort of limit on life comical.

You'd be more logical worrying that we'll run out of carbon and/or nitrogen, since we need alot more of them 'non-trace' minerals than we need selenium, silicon, etc.

"Every gun that is made, every warship launched, every rocket fired, signifies in the final sense a theft from those who hunger and are not fed, those who are cold and are not clothed."

[ Parent ]

Or .... (none / 0) (#306)
by mrt on Sun Apr 17, 2005 at 04:14:38 AM EST

You'd be more logical worrying that we'll run out of carbon and/or nitrogen, since we need alot more of them 'non-trace' minerals than we need selenium, silicon, etc.

Actually I think that H2O would be the more logical choice given that ~70% of our body weight is made up of the stuff, but I thought I'd let you come up with that one.

And although we need trace amounts of selenium in our bodies, in greater quantities it is actually poisonous. So let's hope it's not too common in the environment.


-

I'd give my right arm to be ambidextrous
[ Parent ]
Good job! (none / 0) (#333)
by michaelp on Thu Apr 21, 2005 at 12:16:52 AM EST

now you are starting to think.

Regarding se, it is only slighly less common in the universe (30ppb) than in the human body (50ppb) and extremly common (13000ppb) in the asteroids, so it is not very likely we will run out of it any time soon.

"Every gun that is made, every warship launched, every rocket fired, signifies in the final sense a theft from those who hunger and are not fed, those who are cold and are not clothed."

[ Parent ]

Trace Mineral War? (none / 0) (#296)
by masher on Fri Apr 15, 2005 at 10:46:29 PM EST

"My recollection is that Alpha Centuri has no planets..."

We don't know this for a fact. While we can (usually) detect a Jovian or Super-Jovian class planet from a great distance, we certainly cannot do the same with an Earth-size or smaller planet.

"Assuming that we are able to travel beyond ...and back in less time than it takes to consume all of the trace minerals in our own solar system..."

While another poster has pointed out how nonsensical this statement is, given that "trace" minerals are quite common, and we need only small traces of them in our bodies, I do wonder at your theory that we will one day use them all up. Do you think that copper, zinc, or selenium change to some other element once we consume them? After all, mankind has been eating carbon for millions of years...and we still have (barring a tiny amount lost to decay) the exact same amount we've always had.

[ Parent ]
RMG ROX TEH HAUS (none / 0) (#307)
by the ghost of rmg on Sun Apr 17, 2005 at 09:19:41 PM EST




rmg: comments better than yours.
[ Parent ]
A question and an answer. (none / 0) (#325)
by mrt on Wed Apr 20, 2005 at 05:19:23 AM EST

We don't know this for a fact. While we can (usually) detect a Jovian or Super-Jovian class planet from a great distance, we certainly cannot do the same with an Earth-size or smaller planet.

How close do we need to be to a star system before we can detect an earth size planet?

given that "trace" minerals are quite common, and we need only small traces of them in our bodies, I do wonder at your theory that we will one day use them all up. Do you think that copper, zinc, or selenium change to some other element once we consume them

Er, no .... my theory is that if there is X trace minerals, and at any one time a single adult needs T minerals in their body, and the population is P, then the time we will run out of trace minerals is roughly when P is such that X = PT.

Is that so difficult to understand?


-

I'd give my right arm to be ambidextrous
[ Parent ]
re: . (none / 0) (#327)
by masher on Wed Apr 20, 2005 at 12:41:59 PM EST

How close do we need to be to a star system before we can detect an earth size planet?

The simple answer is when that planet subtends an angle equal (or greater) to the angular resolution of our best telescopes. Resolving power is related to aperature size...bigger scopes resolve smaller objects. But as you probably know, one can "cheat" and construct a virtual telescope out of an array of many smaller ones. One day a scope array from earth to Saturn may be able to directly image terran-class planets in the nearby star systems.

The reality is a bit more complex, as it also depends on the planet's albedo, distance from its parent star, etc, etc....and astronomers are finding new tricks all the time which changes the equation.

"my theory is...[snip]...Is that so difficult to understand?"

No, you've explained it clearly. However, if you do work out the 'carrying capacity' for each element in such a manner, by dividing its estimated mass in the solar system by the amount required per human I think you'll be surprised at the result.

[ Parent ]
With unlimited energy comes unlimited recycling. (none / 0) (#328)
by Russell Dovey on Wed Apr 20, 2005 at 03:11:24 PM EST

No Trash.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

Frensel lens? (none / 0) (#85)
by Eight Star on Fri Apr 08, 2005 at 09:55:34 AM EST

It will never fly with that name. Ask anyone what happens when you put a big lens between something and the the sun, and they will say it gets fried. I can see the action movies now.
Call it a 'diffuser' This should also make it simpler to construct since you just have to make it's surface irregular.

And to we have plastics that are transparent to everything that any form of life on earth needs?

But it seems to me that if you want to reduce the amount of sunlight the earth is getting with a big thing at L1, a rock would be simpler. Pick out an asteroid that's the size you want, and strap some thrusters on it. Park it in front of the sun. If I'm doing my math right you would only need something like 10km across to block 1% of the sun.
It's big, but we don't have to lift it from the surface, so this might use less fuel. It's certainly simpler to engineer.

Want something more adjustable? Build a big flat (opaque) space station. Basically a solar sail, but too heavy to go anywhere. If you want to let more sunlight through, tilt it so it's edge-on, or somewhere in between.
Mylar would work for the sun-blocker, plus you could put any instrumentation you want on it (SOHO).

Tried moving a 10km asteroid lately? (none / 0) (#160)
by badtux on Sat Apr 09, 2005 at 12:35:48 AM EST

Hell, we can't even get to the Moon anymore, much less to the asteroid belt, which is the nearest place you can get a 10km asteroid! And once you get to the asteroid, how are you going to move it? Remember your Physics 101, where a=f/m? Well, the m in this equation is *HUGE*. To get even the feeblest acceleration needed to get an asteroid to near Earth orbit within a decade or so would take enormous rockets and millions of tons of fuel.

The thing about a fresnel lens is that you don't have to go to the asteroid belt to get it, and you don't have to haul millions of tons of fuel to the asteroid belt to get it into place. It's just plain more practical.

- Badtux the Practical Penguin
In a time of chimpanzees, I was a penguin
[ Parent ]

re: Tried moving a 10km asteroid lately? (none / 0) (#310)
by interstel on Mon Apr 18, 2005 at 01:54:07 AM EST

No new technology has to be invented to move a 10km asteroid. Existing technology can be used.

Both of the following methods use NIRVA nuclear engines to get to the asteroid belt. And before you say they dont exist. Please refer to the test prototype built and operated for 9 straight months at end of the 60's thru I believe it was 72 to prove a round trip Mars run could be done with the engine.

Method 1:
bring along mass driver and solar power equipment to put into place on the asteroid and use it on mass for propulsion. Slow but steady will work every time.

Method 2:
bring along a large supply of small nuclear warheads and simply use them as propulsion. This means choosing an asteroid capable of handling the explosions but by dropping them in the resulting crater at regular intervals you get thrust.

Just because it sounds like Science Fiction doesn't mean it is.

Interstel

[ Parent ]
Oh, I'm sure (none / 1) (#90)
by losten on Fri Apr 08, 2005 at 10:50:37 AM EST

the solar astronomers would be thrilled to have a light-scattering object between us and the Sun.

Dark Side of the Moon (none / 0) (#126)
by werebear on Fri Apr 08, 2005 at 04:47:19 PM EST

Which is perhaps instead yet another reason why we need more telescopes - or better still one day actual observatories - in space.

http://en.wikipedia.org/wiki/Solar_and_Heliospheric_Observatory

Not having to deal with the Earth's atmosphere pays massive dividends for any observation. Better still, the dark side of the moon could be a great potential location - blocked off from a lot of the EM radiation from Earth.

http://en.wikipedia.org/wiki/Far_side_(Moon)

IMHO it is a shame that they are de-orbiting Hubble before a replacement for it is ready.

There are some interesting projects currently ongoing involving distributed arrays of orbital telescopes

[ Parent ]

I have a better idea. (none / 1) (#96)
by tonyenkiducx on Fri Apr 08, 2005 at 11:25:53 AM EST

Smaller Humans. Now stick with me, this is a scientific leap of faith(fate?). If we genetically engineer all our future generations to be, say, 1 metre tall, we can take up less space, lower our food consumption and significantly reduce heating bills with our new tiny houses. The possibilities are endless!

Tony.
I see a planet where love is foremost, where war is none existant. A planet of peace, and a planet of understanding. I see a planet called
good in theory (2.75 / 4) (#108)
by Cloud Cuckoo on Fri Apr 08, 2005 at 12:49:52 PM EST

but they will just buy bigger SUVs to compensate for  the even tinier penises.

[ Parent ]
ok then (none / 1) (#154)
by QuantumG on Sat Apr 09, 2005 at 12:14:44 AM EST

Just give all our children bigger penises.

Gun fire is the sound of freedom.
[ Parent ]
the penis is metaphorical (none / 0) (#157)
by Cloud Cuckoo on Sat Apr 09, 2005 at 12:22:37 AM EST

representing innate human insecurity / desire to dominate.

[ Parent ]
Engineer more balanced psyches. (none / 1) (#167)
by guidoreichstadter on Sat Apr 09, 2005 at 12:59:34 AM EST

and have copious amounts of sex.


you are human:
no masters,
no slaves.
[ Parent ]
killing 50%? (none / 1) (#197)
by DrWhat on Sun Apr 10, 2005 at 11:11:09 AM EST

How about killing 50% of the planets population?

No , really...

It sounds cruel but is not actually that bad idea.

Small countries/nations with less than 5 million people can participate with 15%
Lets start with China, India, Africa and N & S America

[ Parent ]

You first. (none / 0) (#214)
by Ward57 on Mon Apr 11, 2005 at 02:44:50 AM EST

No Text.

[ Parent ]
why? (none / 0) (#217)
by khallow on Mon Apr 11, 2005 at 04:40:40 AM EST

Before we shrink the human race, kill off half of it, or put gigantic lens in space, we should first demonstrate that a problem exists that can't be solved through more mundane and/or ethical means.

Here, population growth doesn't seem that big an issue. In every country where living standards and wages rose, population growth has declined or even gone negative.So raise the standard of living and population decline follows, right? Where's the problem?

Stating the obvious since 1969.
[ Parent ]

50%? Ha! (none / 0) (#275)
by cdguru on Wed Apr 13, 2005 at 12:50:36 PM EST

The last time the Earth was in a "sustainable" environment was around 1850. This is when two things were occurring:
  1. Energy use byproducts (heat, ash, CO2, etc.) were naturally reabsorbed and reprocessed.
  2. Fuel was being replenshed at a rate near its consumption.
After that time, we have been unable to get energy use byproducts out of the environment by natual means. Sure, we're just burying them somewhere today, but that doesn't make them go away. Think about coal ash (cinders), for example. Also, think about where the excess heat is going - it sure isn't just being radiated into space.

We would need to get the population and energy use levels down to 1850 levels to have a truely sustainable, closed-cycle system. That would be maybe 200 million people. Not 3 billion. I think more like 100 million would be reasonable for this sort of thinking. We would need to eliminate 5.9 billion people to reach that level or about 98% of the people on the planet. We would need to do this pretty soon, so we better start right now - if we want to treat the Earth as a closed-cycle system. Think about a million people a day being killed for 20 years - that is about what it would take. War isn't going to do the job - even a US-Russia nuclear exchange in the 1960's would have killed only hundreds of millions, not billions.

I think we better seriously consider exploiting outside resources - those that are not on Earth. Unless you really think someone can sell the idea of killing off 98% of the human race to "save the planet".

[ Parent ]

Obviously (none / 0) (#100)
by Sgt York on Fri Apr 08, 2005 at 11:36:58 AM EST

Someone just needs to get some big-ass ice cubes and drop them in the ocean. Or get all the robots to stand on an island and burp/fart up to push us into a more distant orbit.

Perhaps an easier solution is to not rely on one thing. New nuke plants, combined with solar and wind, conservation, and add in a few things like CWT's trash-to-oil thing. (Pretty cool stuff, they even already have a functional plant online, turning turkey processing leftovers into crude oil, suitable for making fuel oil, gasoline, and heating oil).

There is a reason for everything. Sometimes, that reason just sucks.

CWT is neat, but... (none / 0) (#351)
by beergut on Wed Apr 27, 2005 at 03:08:06 PM EST

Not to sound like a conspiracy-monger, which I am to a degree, but hey... if the shoe fits...

I was at the CWT plant in Carthage, MO the other day. Pretty impressive, even though I didn't get to buy gas cheap (heh...).

However, the state and federal governments are trying to shut the plant down, from what I've heard, due to the noxious smell from the plant.

I was there, as I said, and didn't smell a thing (well, nothing except the omnipresent smell of poultry innards.)

Keep in mind that this plant is plopped right in the middle of a poultry-processing facility. In Missouri. In the summer, 100+-degree heat and 99% humidity will make the whole region positively reek with all the nastiness coming into and out of that facility. Even if there was a smell from that plant, my thought is that it would be gobbled up (pun intended) by the ambient stench of normal operations.

Why, then, would the state and federal governments be trying to shut it down?

Money, perhaps? The big-oil guys say, "Hey, that's working, and it'd be cheaper to roll out a bunch of these things than to fight wars in a sandbox, but we've already got our infrastructure in the sandbox, so we want the kaibosh put on this technology."

Nah. Couldn't be.

Too much like conspiracy.

i don't see any nanorobots or jet engines or laser holography or orbiting death satellites.
i just see some orangutan throwing code-feces at a computer screen.

-- indubitable
[ Parent ]

Too funny (1.16 / 6) (#101)
by cosmicv on Fri Apr 08, 2005 at 11:44:46 AM EST

I always get the biggest giggle out of people talking about the earth flooding if the polar ice caps melt...

as if they forgot their basic 1st grade physics where ice "expands" in volume - taking up more space.

To convert all the polar ice to water would take up LESS space, thereby dropping ocean levels at worst, but most probably just leave them as they are once the mass/displacement is worked out.


HHHAHAHAH no* ur wrong (2.50 / 4) (#102)
by MrLaminar on Fri Apr 08, 2005 at 11:54:05 AM EST

Actually, you're right about the volume speculation. However, the polar ice caps are not submerged in water. That means that while your little jedi mind trick is valid for icebergs, it is invalid for the polar ice caps and other regions with permafrost.

"Travel & Education. They will make you less happy. They will make you more tolerable to good people and less tolerable to bad people." - bobzibub
[ Parent ]
Not even icebergs (2.33 / 3) (#103)
by flo on Fri Apr 08, 2005 at 12:11:36 PM EST

Yes, they take up more space than the same mass of liquid water. Which is why part of it sticks up above the water surface when it floats. It still displaces the exact same volume of water corresponding to its mass. This is why the water level in your glass doesn't change as your ice-cubes melt.

And another reason for rising sea-levels is not just more water in the oceans, but also thermal expansion of the water itself.
---------
"Look upon my works, ye mighty, and despair!"
[ Parent ]
Yeah, I know (none / 0) (#117)
by MrLaminar on Fri Apr 08, 2005 at 02:42:53 PM EST

nt

"Travel & Education. They will make you less happy. They will make you more tolerable to good people and less tolerable to bad people." - bobzibub
[ Parent ]
You know that Antarctica is a continent, yes? (3.00 / 3) (#132)
by cburke on Fri Apr 08, 2005 at 06:04:15 PM EST

As in a land mass.  As in land covered in ice that isn't in the oceans, so should the ice cap melt it will flow into the oceans and raise the water level.  Same with Greenland, etc.

In other words your knowledge of 1st grade physics couldn't save you from your ignorance of 1st grade geography.

[ Parent ]

that might go for you as well... (1.00 / 2) (#213)
by cosmicv on Sun Apr 10, 2005 at 10:09:43 PM EST

I was hoping I wouldnt have to point out there is no land under the north pole...

While there may be some net increase from the south poles ice, you cant say the entire effect of all the ice melting would go directly into raising ocean levels... as your leaving out the drop in ocean levels from the ice at the north pole unfreezing - so once again, your prediction for global innundation is speculative if not complete unproven fluff.

[ Parent ]

No, just you. (none / 0) (#228)
by cburke on Mon Apr 11, 2005 at 09:47:17 AM EST

I was hoping I wouldnt have to point out there is no land under the north pole...

You don't have to; that's why I said Antarctica and Greenland, not the Arctic.

as your leaving out the drop in ocean levels from the ice at the north pole unfreezing

Perform this experiment:  Put water in a glass, then float some ice on top of the water.  Mark the water line, then allow the ice to melt.  Observe how the water line stays at exactly the same place.  If you wish to discover why this is, some key words to search on would be "water displacement" and "buoyancy".

It seems I was premature in crediting you with knowledge of 1st grade physics.

so once again, your prediction for global innundation is speculative if not complete unproven fluff.

The only thing speculative and unproven is the idea that you have any idea what you are talking about at all.

Melting the ice on the land masses will cause the ocean level to rise.  There is no compensating effect from the floating ice in the water already.

[ Parent ]

You're right, but temp is more important than ice (none / 0) (#233)
by rpresser on Mon Apr 11, 2005 at 02:01:05 PM EST

Melting the ice on the land masses will cause the ocean level to rise.  There is no compensating effect from the floating ice in the water already.

This is true. However, as others have implied, the effect will be dwarfed by the ocean level rise due to ordinary thermal expansion of the water already in the oceans.
------------
"In terms of both hyperbolic overreaching and eventual wrongness, the Permanent [Republican] Majority has set a new, and truly difficult to beat, standard." --rusty
[ Parent ]
Makes sense. (nt) (none / 0) (#243)
by cburke on Mon Apr 11, 2005 at 08:35:14 PM EST



[ Parent ]
re: Too funny (2.00 / 2) (#145)
by interstel on Fri Apr 08, 2005 at 09:57:00 PM EST

Of course ice has more volume than water and thats why the Arctic and Antarctic iceshelfs are sometimes 2 MILES high!

Melt the ice caps of the planet Terra (and I use Terra because thats its astronomical name not its common name) and the ocean levels world wide would go up about 40 feet.

And just for your information. During the last Ice Age global sea levels were 400 feet lower than today for all the water locked up in ice.

Interstel

[ Parent ]
And you failed first-grade geography. (none / 1) (#329)
by Russell Dovey on Wed Apr 20, 2005 at 03:16:09 PM EST

Antarctica is a continent twice the size of Australia, with an icecap, miles thick, covering the whole fucking thing. So if the south polar icecap melts, we are in some deep blue shit.

Of course, you're right about the north polar ice cap. If you don't count Greenland.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

climate disruption now the preferred term (none / 0) (#106)
by Rhodes on Fri Apr 08, 2005 at 12:44:51 PM EST

so much more descriptive than "global warming"- warming where there are winners and losers. climate disruption captures the essence so much more than the gross world measurement which leads to the climate disruption.

not really (none / 0) (#216)
by khallow on Mon Apr 11, 2005 at 04:12:44 AM EST

"Climate disruption" indicates to me that the climate has been disrupted. It doesn't say how it's disrupted. "Global warming" indicates that the world is warming. That seems more accurate especially since we haven't shown that global warming is going to have any significant impact, ie, will become disruptive.

Stating the obvious since 1969.
[ Parent ]

"a few millimetres thick" (none / 1) (#107)
by ultimai on Fri Apr 08, 2005 at 12:47:20 PM EST

Isn't there fragillity problems here?  If you put into orbit space junk orbiting the earth can get it really bad (they're like bullets!) Or if you leave it in the atmosphere winds/atmosphere/temperature extremes/clouds could do some pretty nasty things to it too.  If it's low enough then even flying objects, rain and other such things can pound the thing.

Pretty far out (none / 0) (#113)
by hardburn on Fri Apr 08, 2005 at 01:42:49 PM EST

The L1 point is pretty far out. A lot further than the moon, in fact. Not much human-produced space junk there to worry about.

OTOH, there is always a problem of natural cosmic junk.


----
while($story = K5::Story->new()) { $story->vote(-1) if($story->section() == $POLITICS); }


[ Parent ]
Not unless it's brittle (none / 0) (#158)
by badtux on Sat Apr 09, 2005 at 12:29:33 AM EST

The thing about a fresnel lens is that if you tear a hole in it, the rest of it still keeps refracting light. So it's not particularly fragile.

In addition, the L1 point is outside of Earth orbit and thus outside the band of junk in orbit around the Earth. There's not much out there other than a single solar observatory that's keeping an eye on the Sun. There's certainly nothing large left in the neighborhood out there that is moving fast enough to be dangerous (relative to the L1 point), everything's in orbit around the sun by the time you get out there so if it was going any faster it went shooting out to a higher orbit where it's no danger. Physics, my friend. And anything big on a highly elliptical orbit in the neighborhood that crossed the Earth's orbit would have been swept up by the Earth long ago, unless it was on a WAY big elliptical orbit, like a comet, that doesn't cross the Earth's orbit very often. Frankly, there's so few objects of that type in the solar system that it's not worth worrying about, especially since a fresnel lens will keep working if it gets a hole in it.

The biggest problem will be gradual erosion and pitting of the surface due to dust and energetic particles causing it to slowly lose its ability to refract light, thus gradually turning it into a light sail that would end up sailing right out of the solar system once the retrorockets were no longer capable of holding it in orbit. However, there isn't much dust in the Earth's neighborhood so this would take quite some time to happen.

- Badtux the Scientific Penguin
In a time of chimpanzees, I was a penguin
[ Parent ]

Whatever... (2.00 / 3) (#110)
by naitha on Fri Apr 08, 2005 at 01:16:30 PM EST

There's no such thing as global warming. It's a natural climate change which was set in motion by God and happens every few thousand years. </RushLimbaugh></FundamentalistChristians>


"To listen is an effort, and just to hear is no merit. A duck hears also."
-Igor Stravinsky,
Solar Power, the wave of the future. (none / 0) (#114)
by Republicrat on Fri Apr 08, 2005 at 02:03:35 PM EST

It seems we are well on our way to building giant space-lasers that harness the power of the sun to destroy incoming alien fleets.

Global warming is a myth (none / 1) (#118)
by splitpeasoup on Fri Apr 08, 2005 at 02:47:01 PM EST

The good folks on FreeRepublic told me so.

"Be the change you wish to see in the world." - Gandhi

Why a lens? (none / 0) (#121)
by jeti on Fri Apr 08, 2005 at 03:42:23 PM EST

Why would one need a lens?

I guess a dark material would heat up too much and burn. But a highly reflective foil will likely be lighter and more easy to produce. I guess the light and solar wind would put more pressure on a parasol than on a lens.

But what if you offset the structure from L1 so that pressure and gravity even out each other?


L1 isn't stable. (2.50 / 2) (#122)
by FieryTaco on Fri Apr 08, 2005 at 03:51:29 PM EST

If something falls away from L1, then it doesn't come back. Which is different from L4 & L5 which are stable and collect junk.

[ Parent ]
Exactly what I was going to say ... (none / 0) (#203)
by dougmc on Sun Apr 10, 2005 at 12:47:11 PM EST

but you beat me to it. :)

[ Parent ]
Right, but not the point. (none / 0) (#209)
by rpresser on Sun Apr 10, 2005 at 07:25:39 PM EST

Of course it isn't stable, but no other L point is between us and the sun.  L1 was considered a good place for SOHO, after all. It's not stable but the requirements for stationkeeping are not significantly worse than any other orbit.
------------
"In terms of both hyperbolic overreaching and eventual wrongness, the Permanent [Republican] Majority has set a new, and truly difficult to beat, standard." --rusty
[ Parent ]
True (none / 0) (#256)
by Cat Huggles on Tue Apr 12, 2005 at 04:10:08 AM EST

But applying a constant light pressure may just move the effective L1 point to another place. I'm not quite certain about the exact nature of the instability, so this might be wrong.

For an object with an mass-area density much higher than 1.5 g/m^2, the light pressure can be regarded as a perturbation.

[ Parent ]

Light pressure (none / 0) (#156)
by badtux on Sat Apr 09, 2005 at 12:18:40 AM EST

Do the math. A reflective surface a couple of kilometers in size is a light sail, and will go soaring out of the solar system pushed by the photons coming from the sun. A lens, on the other hand, merely redirects the sunlight, thus has no light pressure on it other than any small lossage that might be there, and thus will just sit where we place it. One thing that would happen with the fresnel lens solution is that as it gets pitted by cosmic dust and gets holes torn into it by the occasional piece of space debris, it will slowly lose its transparency and turn into a sail. But that will happen slowly, and there's plenty of time to prepare a new one before the old one becomes too much of a sail to hold in place with the small retrorockets that are occasionally adding spin and direction to it.

- Badtux the Astrophysicist Penguin
In a time of chimpanzees, I was a penguin
[ Parent ]

Ahh, but you forget the mass of the sail (none / 0) (#165)
by guidoreichstadter on Sat Apr 09, 2005 at 12:54:32 AM EST

There is an equilibrium- the attractive gravitational force and the repulsive force from light pressure balance for a sail with the proper surface area to mass ratio. Above that, the sail leaves the solar system, below it, the sail plummets into the sun. The sail simply cannot be located precisely at the L point if is to be stable; taking light pressure into account places the equilibrium position closer to the sun.


you are human:
no masters,
no slaves.
[ Parent ]
L1 point (none / 0) (#173)
by badtux on Sat Apr 09, 2005 at 04:01:40 AM EST

If an object is at the L1 point it is already in orbit around the sun with the gravitic attraction between the object and the sun being counterbalanced by the gravitic attraction between the object and the Earth and by the outward portion of the object's energy vector. Apply force to the object from sunward, and you move it out of the L1 point, causing it to ascend in orbit until the outward portion of the object's energy vector PLUS the solar force equals the (now weaker) pull of the Sun. The net result is that, as long as the sail faces the sun, it will spiral outwards into higher and higher orbits until it finally hits escape velocity and exits the solar system.

By banking the sail you can reduce the photonic pressure upon the sail, or even reduce its forward velocity and thus cause it to fall into a lower orbit (or even spiral into the sun if you so desire). But then you also reduce its shadow, which is sort of the whole point of the exercise. It might be possible, by banking a slightly-reflective lens, to keep it at L1 without any kind of rockets, just (solar-powered) electric motors adjusting the attitude of "steering vanes". On the other hand, that requires engineering far beyond what is currently feasible for something like the proposed lens.

Note that *NONE* of this has anything to do with the mass of the object. The mass of the object cancels out when you work the actual orbital physics, except insofar as it affects the a=f/m acceleration vector applied by photonic pressure to the sail (ie. a heavy sail would not accelerate rapidly to a higher orbit... indeed, very heavy objects such as, say, the Earth, have neglible photonic acceleration because the mass m of the Earth is so enormous that the feeble f applied by photons results in an 'a' so tiny as to be basically non-existent). Remember, while the gravitic attraction between the object and the sun is higher for a heavy object, so is the energy E=mv and its corresponding outward force vector, the m's cancel. Anyhow, it's bedtime, 'nuff orbital physics for tonite :-).

- Badtux the Orbital Penguin
In a time of chimpanzees, I was a penguin
[ Parent ]

It is much simpler than that. (none / 1) (#181)
by guidoreichstadter on Sat Apr 09, 2005 at 03:00:23 PM EST

The original calculation of the L1 point assumes that the only forces acting on the third body are the gravitational pull of the sun and the earth. Including the light pressure simply shifts the effective L1 point farther from the sun [my error]. It is the same as if the sun's gravitational force of attraction were decreased by the strength of the force from light pressure. The force from light pressure decreases as the inverse square of the distance of the object from the sun, just like the attractive force from the sun's gravity. Including the light pressure is the same as just modifying force of the sun's gravity by a scalar factor less than unity.


you are human:
no masters,
no slaves.
[ Parent ]
It shifts much further than you think. (none / 0) (#287)
by masher on Fri Apr 15, 2005 at 01:07:36 PM EST

What you fail to realize is that for a large, very low density object, solar radiation pressure is a predominating factor. It effectively shifts the L1 point from between the earth and sun to a point on the far side of the Earth-Sun line, where the gravity from both can counteract it. Not a very convienient place to block sunlight. Of course, we could simply make the lens far more massive...which drastically increases the cost of the project. It also means the object has to be nearer the earth, which means a large reflector is required for the same shadow area, and it also increases stresses from tidal forces and other factors.

[ Parent ]
For those wondering about the number here (none / 0) (#257)
by Cat Huggles on Tue Apr 12, 2005 at 04:36:42 AM EST

A surface will receive a light pressure varying approximately as inverse square, so it can balance gravity. If we get too close to the sun, it's weaker than inverse square because we no longer see half the sun, and photons are incident at larger angles.

If our surface is perfectly reflecting, then some basic physics and geometry gives the critical area density as 2*P/(4Pi*c*G*M), where P is the total solar power of the sun (3.86e26 J/s), c is the speed of light (3e8 m/s), G is the gravitational constant (6.67e-11 J m/kg^2), and M is the mass of the sun (2e30 kg). The 2 in front is because the photons are reflected (not simply absorbed), transferring double their momentum to the sail.

For our sun, this density is 1.5 g/m^2.

This is the maximum area density that can accelerate straight away from the sun.

For a regular material, this is something like 1 um thick.

[ Parent ]

Too complex (none / 1) (#127)
by Br4nM4n on Fri Apr 08, 2005 at 04:51:12 PM EST

<sigh>  I've known the correct solution for a long time now, and while this is close, it's too complex.

Very simply, the best way to cool something in the sun is to put it in the shade.  While a 1000 km across freznel lense is an interesting concept, why not just try some simple shade?

With technology we have today - with rockets we have today - we could launch a large round or square shade (maybe 1km square, or 1 mile if you are ambitious) into geosyncronous orbit.  It would be small enough that it wouldn't actually be seen from the ground (sunlight would flow around it enough for that) but would block that light from warming the Earth

Repeat as needed, until the problem is gone.  Can be done gradually - one at a time - to study the effects while doing it.

Too much cooling?  Move some to a slightly different orbit and let more sunlight reach the Earth.  Not enough cooling? Add some more.

Simple.  Doable.  Incremental.  We could start Today.  Why do people have to complicate things?

or put the same thing at L1 (none / 0) (#225)
by boxed on Mon Apr 11, 2005 at 08:08:53 AM EST

It would be much less visable from earth at L1, and wouldn't take up valuable space that can be used for satelites. Furthermore, a big framework of shades at L1 could be a good platform for scientific instruments too.

[ Parent ]
Too hard (none / 0) (#234)
by Br4nM4n on Mon Apr 11, 2005 at 04:04:09 PM EST

While a shade at L1 would probably be more effective than geosyncronous (block more light with the same size shade), L1 is a lot harder to get at. I was thinking of something we could start immediately and at relatively low cost.

[ Parent ]
Just watch out (2.00 / 3) (#131)
by Roman on Fri Apr 08, 2005 at 05:58:21 PM EST

if the lens is put in place backwards instead of 'cooling things off' you may end up heating things up :)

go back to school [nt] (none / 0) (#224)
by boxed on Mon Apr 11, 2005 at 08:06:56 AM EST



[ Parent ]
Swoosh (none / 1) (#251)
by Roman on Tue Apr 12, 2005 at 12:21:40 AM EST

sound a joke makes when it flies over your head.

[ Parent ]
No. Inside-out, you mean? (none / 0) (#245)
by Russell Dovey on Mon Apr 11, 2005 at 09:46:47 PM EST


"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

China and the Kyoto Protocol (none / 1) (#133)
by guidoreichstadter on Fri Apr 08, 2005 at 06:51:07 PM EST

One of the widely cited reasons gibven by the Bush administration for withdrawing from the Kyoto Protocol, an international agreement to limit carbon dioxide pollution which went into force on February 16, 2005, was that the pact did not provide pollution limits for rapidly industrializing countries, notably China.

In the absence of stringent, internationally enforced pollution standards, however, China seems to be taking the initiative towards atmospheric pollution management with the rapid implementation of energy efficiency measures and recently, with the planned construction of 40 new nuclear power plants over the next decade and a half.


you are human:
no masters,
no slaves.

That's great (none / 0) (#137)
by Armada on Fri Apr 08, 2005 at 07:20:15 PM EST

Good story, for those that believe global warming is more than a religion.

I, however, don't.

That link confirms that global warming is real (3.00 / 2) (#138)
by Big Sexxy Joe on Fri Apr 08, 2005 at 07:55:39 PM EST

That first table confirms that man makes 0.28% of greenhouse gases.  Environmental scientists can demonstrate that this is will have a dramatic effect on the climate and cause significant globabl warming.

The paper goes on to state that changes in climate change has happened in the past.  However, climate change has always been a disaster for living things.  The fact that climate change can happen spontenously does not mean that it is not man made this time.

The scientific community is solidly behind global warming.  The scientists who deny it are literally outnumbered by more than a thousand to one.  Denial of global warming is a denial of empirical truth.

I'm like Jesus, only better.
Democracy Now! - your daily, uncensored, corporate-free grassroots news hour
[ Parent ]

also global warming way predates (none / 0) (#176)
by proletariat on Sat Apr 09, 2005 at 11:18:51 AM EST

Stephen Schneider in the 1970s. John Von Neumann, one of the all time greatest minds of the world, believed in it. He died in 1957. I don't know the history of it but the theory has been around for a long time.

[ Parent ]
ok. (none / 1) (#265)
by Armada on Wed Apr 13, 2005 at 12:29:21 AM EST

Just as Christianity is believed by millions, including a MAJORITY in this country (remember that a mere 10% would vote for an atheist as president), I would have to argue that majorities can even be wholly WRONG in their assumptions.

Please direct me to someone who can account for both an increase in global temperature due to carbon dioxide AND (this is the key point here) the decrease from 1945 to 1970 in global temperature.

Even with the latest theories, I've yet to come across anything that definitively and better yet, undeniably, can model such.

[ Parent ]

I'm surprised. (none / 1) (#269)
by ajduk on Wed Apr 13, 2005 at 04:29:52 AM EST

You come out with the above as if you were familiar with climate research.. yet this could be seen in the 2001 IPCC report: The black line is temperature observations, Red, orange and Blue different models, and Green ignores GHG and Aerosol effects. You will note both the good agreement - despite the models being 6 years or more out of date, which is a LOT in a rapidly evolving field such as this, which is also dependant on computing power. And, of course, the slight 1930-1970 temperature decrease.

More recent research (See page 36 for summary graph) gets even closer; given year to year variability in climate, it's hard to see how a model could be more accurate. So I do find it really hard to see how you have problems with this.

There are a considerable number of people who propose solutions which appear ideologically motivated - wind, hydrogen and bio-ethanol would be examples of solutions which don't make engineering and/or ecological sense. But this is nothing to do with the validity of the science behind global warming.

[ Parent ]

Ok. (none / 1) (#279)
by Armada on Wed Apr 13, 2005 at 11:52:31 PM EST

I have a familiarity with climate research. Actually, I even have a friend who is in it and a very hardcore global warming activist. We disagree on a number of issues. I have seen the IPCC report and I'm familiar with the arguments made.

What I haven't seen is a formula that appropriately models the temperature of the last hundred years. Here again, I looked specifically at the link you provided and still do not see a simple graph stating the obvious; here's the actual temperatures over X number of years, and here's what our model predicts those temperatures should be, using carbon-dioxide levels specifically as the determining factor.

Part of my frustration on the issue is that I'm a layman, and in order to understand the issue, it has to be presented to me in a no-bullshit kind of way. BOTH sides are guilty of skewing data and reports and even worse, politicizing their views.

I just wish someone would say, here's why there's an issue, without being cryptic about it, being straightforward, and publishing real numbers. I'm not expecting a model to be dead-on accurate, but no where have I see anything that says: here's what the temperature was, and here's the model that closely matches it. Instead, you get 15 different models and combined they are supposed to show that global warming can be directly attributed to levels of GHG. I'm sorry, but I don't buy it. I want a no-bullshit approach.

Perhaps I'm asking for too much, but what I've seen has yet to convince me. Not even in the slightest. I realize that all we really have to work with is maybe 60 some years of reasonably accurate temperature data, but damn, you'd think there'd be SOMETHING that could definitely say it with as much press as this issue gets.

I have another friend who says global warming exists, gets in my face about the issue and can't even explain what Urban Heat Island Effect is, nor could he name three greenhouse gases on request. It frustrates me, because I'm of the opinion that several climatologists aren't actually out to educate the public, they are simply using scare tactics and FUD to freak people out. And sadly, it appears to be working quite well!

[ Parent ]

Errm.. (none / 1) (#280)
by ajduk on Thu Apr 14, 2005 at 04:24:48 AM EST

You see, this is where I get confused. First you are saying:

I have a familiarity with climate research.

And then in the next paragraph:

..and here's what our model predicts those temperatures should be, using carbon-dioxide levels specifically as the determining factor.

If you actually read the references I gave - and the references behind then, et. al, you would understand that this is not the case. The warming from c. 1900 to 1930 is generally NOT attributed to GHGs - Solar influences (Which can be modelled/measured) are thought most likely to be responsable. A definate GHG signature - where there is no other way of accounting for the observations - is only seen from around 1980 onwards. People familiar with the research are generally aware of this.

As far as FUD goes, I find the 'skeptic' side to be far worse - they are quite happy to claim things like 'Global cooling was universally predicted in the 1970s', 'Cosmic rays are responsable for everything', 'We are just coming out of an ice age', 'Water is responsable for 98% of the greenhouse effect', or any of several other arguments which are long debunked and for which the debunking can be easily found. Yet they are repeated as a mantra. And economist's projections of the costs of stopping global warming are accepted without question by 'skeptics' despite the appalling record that economics has in projection. Apparently replacing coal and gas burning - which is only going to become more expensive as more marginal resources are exploited - with Nuclear plants, which become cheaper as technology improves over time (fuel costs being insignificant) would damage the economy. Go figure.

[ Parent ]

I disagree. (none / 1) (#334)
by Armada on Thu Apr 21, 2005 at 09:42:46 PM EST

As far as FUD goes, I find the 'skeptic' side to be far worse - they are quite happy to claim things like 'Global cooling was universally predicted in the 1970s', 'Cosmic rays are responsable for everything', 'We are just coming out of an ice age', 'Water is responsable for 98% of the greenhouse effect', or any of several other arguments which are long debunked and for which the debunking can be easily found.

First off, look up the definition of FUD. Skeptics are NOT the ones crying chicken little.

Second, I encourage you to refute the first and fourth of the "mantras" you say that the skeptics continue repeating. There is a reason, its because they've never been refuted.

If you actually read the references I gave - and the references behind then, et. al, you would understand that this is not the case. The warming from c. 1900 to 1930 is generally NOT attributed to GHGs - Solar influences (Which can be modelled/measured) are thought most likely to be responsable.

Yes, but you're missing the point. In order for a model to be accurate, it has to encompass all known factors for the time period in question. Solar activity might account for the 1900s to 1930s, but where is the GHG model for that era? Arguably, the bulk of the growth since the industrial revolution has been from the 1910s till present day. Where is the greenhouse gas model that accounts for all three: the increase from 1900 to 1940, the decrease from 1940 to 1970, and the increase from 1970 to present?

My biggest problem with GW activists is they seem to negate the fact that we were growing industrially from 1940 to 1970 just as fast as from 1900 to 1930 (probably moreso because of WWII and the economic boom that followed).

These issues HAVE NOT been debunked. They've been IGNORED. I wouldn't be so frustrated if someone attempted and failed to model the last century with regards to carbon-dioxide having more of an impact than water vapor, but no one has even tried, which leads me to believe that GW activists are fear mongers.

As far as the economic argument that nuclear power is to be avoided, I'm 100% behind you on that one, there's no reason we can't have nuclear power replace coal. We CANNOT have solar and wind energy replace it though. I think there is a great deal of FUD on the part of the anti-nuclear plant crowd.

[ Parent ]

WTF? (none / 1) (#335)
by ajduk on Fri Apr 22, 2005 at 11:09:27 AM EST

First off, look up the definition of FUD.

Fear, uncertanty and doubt. Are you (with a straight face) telling me that the 'skeptics' are not spreading Fear ('Reducing carbon emissions will destroy the economy'), Uncertanty ('No one really knows what will happen') and doubt?

Second, I encourage you to refute the first and fourth of the "mantras" you say that the skeptics continue repeating. There is a reason, its because they've never been refuted.

Point 1: I am right, you are wrong.

Point 4: I am right, you are wrong

Yes, but you're missing the point. In order for a model to be accurate, it has to encompass all known factors for the time period in question. Solar activity might account for the 1900s to 1930s, but where is the GHG model for that era?

You see, this is why I added the qualifier 'If you actually read the references'. You didn't; you are asking questions that are answered, and have already been answered.

[ Parent ]

Accurate modeling? A few gems. (none / 0) (#336)
by masher on Fri Apr 22, 2005 at 04:19:07 PM EST

Physical Review Letters, July 8, 2002.  Global Warming Climate models fail to reproduce real temperature records.

Geophyiscal Research Letters, Aug 28, 2002.  Paper detailing a ~40 degree error in climate models in predicting polar temperatures.

Jan 10 2003, Geophysical Review Letters.  Greenhouse effect may be weakening due to cloud cover changes not predicted by global models.

Mar 2003, Annual Meeting of American Meteorological Society, NCAR researcher finds atmospheric models grossly underpredict atmospheric humidity, overpredict warming.

Oct 2003, Energy and Environment.  Statistical modeling in IPCC Third Assessment Report is inaccurate; the "hockey stick" graph of rising global temperatures is inherently flawed.

July, 2003.  Geophysical Review Letters.  Past sea-level rise significantly mispredicted by IPCC model.

Mar, 2004, Climate Change.  Greenland temp data shows long-term cooling trend; only period of warming was in 1920s; Model fails to predict.

Aug 2004. UAH Earth Science Department.  3-month trend continues.  Global temperatures cooler than 20-year average.  

Dec 2004, Annals of Glaciology.  Team of Researchers find link betwen solar activity and polar warming, not GHGs.

[ Parent ]

Good post, for those who believe... (none / 0) (#246)
by Russell Dovey on Mon Apr 11, 2005 at 09:50:17 PM EST

...that you are more than an ignorant slop-fed redneck with delusions of self-worth, and that I actually care to listen to your ravings.

I, however, don't.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

I highly doubt this will work (none / 0) (#140)
by Big Sexxy Joe on Fri Apr 08, 2005 at 08:07:23 PM EST

There's plenty of metorites and smaller pieces of junk flying through space.  So when one of those passes through this 785398 square kilometer surface faster than a bullet, it will probably crack the whole thing.

By the way, where are they going to build this thing?  How are they going to put it into space.

By the way, did Russell Dovey make this whole thing up?  None of his many links actually explain this solar lens scheme.

I'm like Jesus, only better.
Democracy Now! - your daily, uncensored, corporate-free grassroots news hour

Holes? So What? (none / 0) (#198)
by kenmce on Sun Apr 10, 2005 at 11:46:35 AM EST

If this is ever built they will design it to survive impacts.  The simplest way is to make it mechanically weak enough that passing objects knock a small hole in it and keep right on going like a beebee through a plate glass window.

If the hole and the damaged area around it equal, say, one-millionth of the capacity of the shield you either send a repair crew up there or simply replace it after every hundred thousand impacts or so.

The problem I see with the scheme is that this thing would make a dandy weapon - just concentrate a few square kilometers of sunlight onto anything that annoys you and it will go away.

Since the weather is basically a heat engine this device will also allow you to monkey with other peoples weather.

[ Parent ]

eh, no it won't make a weapon (none / 0) (#223)
by boxed on Mon Apr 11, 2005 at 08:05:12 AM EST

The lense is made to DIFFRACT light, not concentrate it, meaning you can't ever use it as a weapon. Sorry.

[ Parent ]
Depends How They Do It (none / 0) (#239)
by kenmce on Mon Apr 11, 2005 at 05:51:23 PM EST

If the entire affair is made out of fixed or semi-fixed pieces, then you would be right.  However if it is made of fully adjustable pieces you could configure it however you wanted.  It would have a number of potential civilian uses.  You could provide a significant amount of light and heat anywhere you choose.

[ Parent ]
eh, are you serious? (none / 0) (#283)
by boxed on Fri Apr 15, 2005 at 05:02:22 AM EST

Adjustable pieces would push the price at least to an order of magnitude higher, probably even more, maybe even making it impossible to build.

[ Parent ]
Why not? (none / 0) (#297)
by masher on Fri Apr 15, 2005 at 11:25:53 PM EST

"Adjustable pieces would push the price at least to an order of magnitude higher, probably even more..."

False, given that the majority of the project price is launch cost. A little thought should convince you the absolute worst case would be double the price, since you could simply build one of each type lens, and edgeline the one not in use.

In reality, it would be far simpler than this. The geometric difference between a planoconcave (diverging) fresnel and a planoconvex (converging) one is quite small-- a matter of canting the angle edges of each ring. I'm quite sure a design based on tensioning cables or pressure-adjustable inflatable spoke ribs would add very little to the cost.

[ Parent ]
do you have an adjustable fresnel lens handy? (none / 0) (#320)
by boxed on Tue Apr 19, 2005 at 07:25:25 AM EST

Making a fixed fresnel lens is very very cheap, a matter of just making a mold and pouring plastic on it. Making some kind of adjustable thing would be terribly hard, given that each ring of such a large ring would be just a millimeter thick plastic.

[ Parent ]
Ah contraire... (none / 0) (#321)
by masher on Tue Apr 19, 2005 at 12:43:17 PM EST

> "Making a fixed fresnel lens is very very cheap,
> a matter of just making a mold and pouring plastic on it..."

Ah, but we can't make this lens in such a manner, now can we?  There aren't many molds 1000 km in diameter.  So we already have to cast this in many millions of smaller pieces, then assemble it.  

A fresnel lens doesn't have to be solid...the individual pieces don't even need to touch. Cabling them together with a small degree of open space between each would probably be one of the cheapest methods, plus it would give the structure a high degree of flexibility and redundandancy against the breakage or failure or any single part.  Fringe effects around each piece would destroy the optical quality of an image-grade lens...but simply for focusing or diffusing light, it wouldn't be a problem.

Now, given all the above, how much extra would it add to replace those fixed cables with an adjustable tensioning system, that would be able to cant individual sections at varying angles?  Not much at all.

Q.E.D.

[ Parent ]

Eh, you're still full of it (none / 0) (#324)
by boxed on Wed Apr 20, 2005 at 04:43:21 AM EST

The individual parts are triangular in cross-section, that's what makes the fresnel lens work at all. The only way to make a gigantic fresnel lens adjustable like this would be to make each section _rotateable_.

[ Parent ]
Get a grip... (none / 0) (#326)
by masher on Wed Apr 20, 2005 at 11:42:44 AM EST

<i> "The only way to make a gigantic fresnel lens adjustable like this would be to make each section _rotateable_..."</i><br><br>

Good god, are you really so dense?  Cable two sections together at top and bottom.  Now, winch in the top cable slightly, while leaving the lower cable alone.  What happens?  The sections ROTATE slightly towards each other.<br><br>

Now scale that up to a huge fresnel lens.  Loosely cable the prism sections concentrically at each end to its nearest neighbor, leaving it free to rotate.  Cable it axially across the top and bottom face, with "spokes" radiating out from lens center.  Now, tighten only the top (or the bottom) cables, and you suddenly have an adjustable fresnel lens.<br><br>

To adjust it accurately, you'd either need a cable with nonlinear characteristics, or you'd need additional actuators along the spokes every few kilometer...you don't want every section to rotate through the same angle, after all.<br><br>

This is just ONE of the MANY ways an adjustable fresnel lens could easily be constructed.  

[ Parent ]

The numbers don't work. (3.00 / 4) (#141)
by cyberman11 on Fri Apr 08, 2005 at 08:20:54 PM EST

A circle 1000 kilometres (one million meters) across has a radius of 500,000 meters and therefore a surface area of (Pi x R^2) 785 billion square meters. The article says the lens will be "a few millimetres thick". If the lens is slightly more than one millimeter thick, that would be a billion cubic meters of plastic. There is no way we can launch a billion cubic meters of plastic into L1 solar orbit for 10 billion dollars! I think this story is a late April Fools Day joke.

what is the plastic's density? (none / 0) (#254)
by Cat Huggles on Tue Apr 12, 2005 at 03:20:59 AM EST

That's the main thing. If it's made out of something extremely low-density like aerogel, maybe it's not so impractical.

[ Parent ]
Calling all Luddites (3.00 / 3) (#161)
by codejack on Sat Apr 09, 2005 at 12:36:03 AM EST

Quick question for the "Global warming is crap, Rush Limbaugh told me so!" crowd: What, exactly, is it that the scientists are supposed to be gaining from advancing a false theory such as this? I mean, it's pretty clear what the ulterior motive behind Exxon's- I mean, Bush's pullout from the Kyoto Accord, etc, is; Money. What is not clear is what 99% of scientists would gain by lying to the world, other than making fools of themselves if it does prove false.


Please read before posting.

Ever read "State of Fear"? (1.50 / 2) (#189)
by Fon2d2 on Sun Apr 10, 2005 at 12:17:31 AM EST

I think this is the one dissenting voice I hear coming from what I consider a "qualified" scientific mind. By "qualified" I mean I trust that Crichton does his research. And I think it is certainly quite  possible, actually quite probable, that are temperature data is not all it's cracked up to be. I've certainly seen enough counter-arguments to global warming, sometimes with interesting data and lucid arguments. It's hard to go against Discover and Sci-Am, what I consider to be the peer-reviewed opinions of the scientific community, but the ideas are too tenuous and there's too much debate for me to set a solid foot on the "global warming is real" side of the fence.

Now maybe it's like evolution (which I do firmly believe in) where there's plenty of debate and controversy despite there being no question as to its veracity from the scientific community. And maybe I'm just caught up in that debate and either don't have the motivation or the resources to sort it out.

Or maybe it's like Crichton put in his author's message at the end of "State of Fear". You asked the question what would the scientists have to gain? Maybe that's the wrong question. As Crichton put it, before the second world war, eugenics was a widely believed in and widely discussed science. Debated yes, but it had approval from much of the scientific community as well as many prominent people such as actors and politicians. It was just a sort of global conscienceness. Then WWII happened and the rest of the world was kind of shocked out of their affinity for eugenics. It just sort of wasn't discussed anymore. Could not global warming be in the same state now as eugenics was before WWII?

[ Parent ]

Whoa (3.00 / 2) (#204)
by codejack on Sun Apr 10, 2005 at 01:10:19 PM EST

I'm not sure where to start; First, of course, has to be a short rant against Discover and Scientific-American. These are popular review magazines, with horribly mangled interpretations for "lay" readers. I could say more, but what's the point?

Second, the temperature data is not really in dispute. What is constantly disputed is the question of whether we are causing it, and by how much? This misses the point: Who cares what the cause is if the result is the same?

Third, eugenics was one of those proposals that, in and of itself, was entirely correct. The assumptions that people, such as Hitler, took from it, however, were entirely wrong. You can breed for superiority, but defining superiority and what traits to breed for it is the 50 million dead question.


Please read before posting.

[ Parent ]
Great points, thank you. (none / 0) (#230)
by Fon2d2 on Mon Apr 11, 2005 at 12:07:14 PM EST

One point though. In your original post you seemed to be addressing right-wing conservatives in particular and I'd like to say that like evolution, global warming is not a clear cut issue for a lot of people, whether they lean left or right.

And other questions still exist, like why should the US be bound by the Kyoto Accord when China and India are not and it's clear they're going to be the major players (due to population) in terms of CO2 output in the coming years.

[ Parent ]

Crichton's a hack. (3.00 / 3) (#247)
by Russell Dovey on Mon Apr 11, 2005 at 09:52:06 PM EST

He sensationalises things to make money and gratify his ego. That's the extent of his qualifications.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

Easy: Money and Peer Pressure (none / 0) (#196)
by madgeo on Sun Apr 10, 2005 at 10:01:08 AM EST

It's the same answer for the scientists. I personally know geologists that have altered their grant applications to include a global warming spin so that they could increase their chance of getting a grant! Global warming is such an all encompassing "theory" that it allows for a lot fo disciplines to get on the money bandwagon.

In addition, peer pressure can cause a lot of scientists to get on board. It took 50 years (50!) before Alfred Wagner's Continental Drift a.k.a. Plate Tectonics was widely accepted in the scientific community because 99% of the community didn't believe it. Now of course, 99% would laugh at you if you didn't. Scientists are as human as the next upright ape.

[ Parent ]

So what? (none / 0) (#205)
by codejack on Sun Apr 10, 2005 at 01:17:00 PM EST

So they alter their grant proposals, what's the problem? We're getting more data on the subject to make an objective decision about it. On the flip side, the few scientists who do oppose the concept get much more attention for it, neatly muddling the whole issue of ulterior motive.

And frankly, plate tectonics is maybe not the best scientific theory to use in comparison to support your argument. If you don't want to copy the other poster and use eugenics, try phrenology or Newtonian physics.


Please read before posting.

[ Parent ]
Same reason that politicans rail about immigration (none / 0) (#226)
by Anonymous Howards End on Mon Apr 11, 2005 at 08:39:09 AM EST

Peddling trite solutions to imaginary problems is a whole lot easier than dealing with real ones.
--
CodeWright, you are one cowardly hypocritical motherfucker.
[ Parent ]
Global warming is a myth (1.16 / 12) (#163)
by sellison on Sat Apr 09, 2005 at 12:45:40 AM EST

After exploring the question of global warming, I've found the science behind it to be questionable at best and the economic impact unnecessarily severe, particularly for minority families and businesses. This may raise a question in some people's minds as to why this is being pushed so uncritically by other world governments and by the media.

Well, the first clue comes from a quick perusal down the list of nations from the Kyoto Protocol itself. Some countries like the Russian Federation are simply asked to hold their emissions at 1990 levels with no reduction. Countries from Latin America, Asia, Africa, and Polynesia, including China and India aren't even on the list (except Japan)! The reason is that these countries are still developing their economies and will need unrestricted energy use. However, as these populous nations grow economically, they may well exceed the emissions output of western nations altogether.

Implicitly, this affirms the necessity of fossil fuel energy for healthy economies. This treaty is  just a tax on western nations, not a policy for climate change. The late Aaron Wildavsky, professor of political science at UC Berkeley, wrote, "Warming (and warming alone), through its primary antidote of withdrawing carbon from production and consumption, is capable of realizing the environmentalist's dream of an egalitarian society based on the rejection of economic growth in favor of smaller population's eating lower on the food chain, consuming a lot less, and sharing a much lower level of resources much more equally."

You see, it's all about a way for the discredited policies of socialism to sneak back in, under the guise of "environmentalism". It's just another mask for the deciever, and we Christians know what his goal is...

Christians know our command is to 'go forth and multiply' not stay home and try to conserve. God will provide faithful men and faithful nations with providence, as He has always done, and we can be secure knowing that if He is raising the temperature, it is for good reason (to provide more food for more people)!

Further you see from this article how the unscrupulous socialists are trying to increase the power of the state with this scare tactic, they'd love to tax us to death to build this new Babel!

"No, I don't know that atheists should be considered as citizens, nor should they be considered as patriots. This is one nation under God."- George H.W. Bush

What research papers did you read? (3.00 / 3) (#174)
by badtux on Sat Apr 09, 2005 at 04:10:05 AM EST

Just curious. Did you read the actual research, or did you rely upon the pre-digested conclusions of pundits (or, worse yet, of scientists)? Curious penguins want to know!

The research I've seen shows a fairly significant rise in CO2 concentration in the atmosphere over the past 10,000 years of civilization, with the rise starting to go up rapidly about 2,000 years ago and then spiking almost vertically about 100 years ago. The effects of CO2 upon heat retention by the atmosphere are measurable and have been measured, and it is a significant effect. These are facts, and are not subject to dispute unless you wish to discard science in favor of religion.

Now, the question of whether that additional CO2 will cause massive global weather changes is a seperate question, and necessarily speculative in nature since these changes have not happened yet. However, so is the speculation that if an object is thrown into the air, it will eventually fall to the ground. It is speculation on our part, because if the object were thrown hard enough (by, say, The Bionic Man), it could achieve orbital velocity and never fall. But that is not very likely. As is the notion that global warming is not going to result from the CO2 buildup. Unless the climate has an equivalent of a Bionic Man hiding under the covers, we can pretty well predict that things are going to start getting toasty shortly.

- Badtux the "No bionic man here!" Penguin
In a time of chimpanzees, I was a penguin
[ Parent ]

Well then (none / 1) (#177)
by jolly st nick on Sat Apr 09, 2005 at 11:25:22 AM EST

Christians know our command is to 'go forth and multiply' not stay home and try to conserve.

Well then, you must be against market economics, because market economics are about conserving scarce resoruces by using them efficiently. The issue is one that even the classical economists understood -- the most important things in life, like air, have no market value because they have no market. The difference is that economies now exist on scales that can exhaust formerly inexhaustible resources like the oceans and the air.

For this reason, I like pollution credit trading, depending on how the system is set up, because it maximizes the efficiency with which the scarce environment is used, with well established mechanisms.

WRT to the rest of your post, you seem to be conflating the Kyoto accord with the science of global warming. Also, I found this a bit mystifying:

However, as these populous nations grow economically, they may well exceed the emissions output of western nations altogether.

Why shouldn't it? THere are more people in the poor countries, are you saying that God has given people in western countries a greater right to the atmosphere than people in poor countries? So, we get the benefit of liquidating environmental resources, and escape the consequenes because our assets -- capital, are mobile, and the poor subsitence farmers in the third world are tied to their drought striken land? Dude, the eye of that needle is looking awfully small.

I think Kyoto is flawed becasue its a quota system, and people will simply cheat. Furthermore, everyone will tend to look the other way rather than rock the boat, because the cost of the cheating is externalized. I think a system in which credits can be traded is better, because it provides countries with flexibility.

In the end, the myth isn't global warming, the myth is climate stability. Over the course of thousands of years, the climate shifts around chaotically, periodically establishing new equillibrium points. However, I think very few people are prepared to face the political and economic ramifications of that.

[ Parent ]

False (none / 1) (#199)
by sellison on Sun Apr 10, 2005 at 11:52:05 AM EST

market economics are about conserving scarce resoruces by using them efficiently.

If you stay home and conserve, there is no market. Second market forces are more importantly about finding new sources for resources than about conserving them. It is generally much more profitable to find a new source than tinker about trying to increase a few %points of efficiency.

God put all the oil we'll ever need here on Earth, currently we find it in the Middle East because He does not want us to forget our mission there, but once that is complete, new sources will be found all  over the place.

"No, I don't know that atheists should be considered as citizens, nor should they be considered as patriots. This is one nation under God."- George H.W. Bush
[ Parent ]

(Why am I bothering...) (none / 0) (#178)
by Another Scott on Sat Apr 09, 2005 at 11:30:09 AM EST

Hello again,

After exploring the question of global warming, I've found the science behind it to be questionable at best [...]

Really? What do you question about the science exactly? For instance, what is wrong with the science in this article by McKitrick?

Scientists try to discern local climate histories over past centuries using various techniques, including temperature proxies and ground borehole temperature data. "Proxies" include a wide range of measures that are, potentially, sensitive to local temperature trends, such as tree ring widths. Boreholes drilled into the ground have a vertical temperature profile that can be inverted to yield an estimate of the historical surface temperature sequence at the surface.

Please address the science and not the politics.

Cheers,
Scott.

[ Parent ]

Nothing (none / 1) (#191)
by sellison on Sun Apr 10, 2005 at 01:53:22 AM EST

"Figure 8 shows two versions of the hockey stick chart. The dashed line is the MBH98 version. The solid line applies the corrections to methodology and data discussed in this paper. (More detailed step-by-step diagrams are provided in our 2005 Energy and Environment paper). The Mann multiproxy data, when correctly handled, shows the 20th century climate to be unexceptional compared to earlier centuries. This result is fully in line with the borehole evidence. (As an aside, it also turns out to be in line with other studies that are sometimes trotted out in support of the hockey stick, but which, on close inspection, actually imply a MWP as well.)"

McKitrick thouroughly debunks the myth of global warming, I don't have a problem with that.

"No, I don't know that atheists should be considered as citizens, nor should they be considered as patriots. This is one nation under God."- George H.W. Bush
[ Parent ]

I thought so... (none / 0) (#195)
by Another Scott on Sun Apr 10, 2005 at 09:19:41 AM EST

You don't understand McIntyre and McKitrick's work and their criticism of Mann.

Their criticism is with 1) the politicization of the IPCC report; 2) Mann's use of bristlecone pine tree ring data as a temperature surrogate (when it's more likely to be a CO2 surrogate); and 3) Mann's Principal Component data analysis techniques of the data.

They don't dispute the science at all - in fact they each use the scientific method to make their claims.

You don't seem to understand that science is a process. It's not a particular result. MM and Mann are continuing to make the case for their interpretations of the data. They're continuing to refine their arguments and apply new data to the problem. That's the way science works.

Finally, MM discuss their views on global warming in a FAQ on their Climate Audit web site:

Does your work disprove global warming?

We have not made such a claim. There is considerable evidence that in many locations the late 20th century was generally warmer than the mid-19th century. However, there is also considerable evidence that in parts of the Northern Hemisphere, the mid-19th century was exceptionally cold. We think that a more interesting issue is whether the late 20th century was warmer than periods of similar length in the 11th century. We ourselves do not opine on this matter, other than to say that the MBH results relied upon so heavily by the Intergovernmental Panel on Climate Change in its 2001 report are invalid.

Mann's web site is Real Climate.

Taking MM's results as a debunking of global warming shows that you really don't understand the science and that you're more interested in spinning things to match your politics and religious dogma. But I think we already knew that.

Cheers,
Scott.

[ Parent ]

Why do you pretend to be interested in Debate? (1.33 / 3) (#200)
by sellison on Sun Apr 10, 2005 at 11:58:04 AM EST

Then try to censor my post you claim to want to debate? Another Scott      1

Typical liberal, you claim to be a reasonable 'scientific minded' not afraid to debate someone who disagrees with you, but really you just want to hear your own side talk.

So you take every chance you get to suppress any opposing views.

This is the same reason the 'global warming' 'debate' is such a fraud, scientists in the currently dominant pro-warming clique use every nasty little trick they can find to suppress their opponents, all the while claiming to be engaged in a high minded 'search for the truth'!

But your science is really just about politics, about tenure, prominence in conferences, prestige. You are no more rational and fair minded than a bunch of apes pounding their chests over the best bananna tree.

"No, I don't know that atheists should be considered as citizens, nor should they be considered as patriots. This is one nation under God."- George H.W. Bush
[ Parent ]

My understanding is... (none / 0) (#202)
by Another Scott on Sun Apr 10, 2005 at 12:34:15 PM EST

1 = Discourage. Your comments seem to quite often be a combination of short initial comments on a topic, then long tangents into politics and religion. My 1 was to discourage comments like that because I think they're off-topic.

Our earlier converstation in the Terri comments disappeared for a while because of all the zeros. I didn't want that to happen this time so I gave your comment a 1. My understanding is that comments are hidden when 0 dominates. I didn't want that to happen this time around, but I did want to discourage comments like the one rated.

You're free to post (and throw in ad hominem when you feel like it), and I'm free to comment and rate. That's the way it works.

YMMV.

HTH.

Cheers,
Scott.

[ Parent ]

Liberals always have some fancy (2.00 / 2) (#211)
by sellison on Sun Apr 10, 2005 at 09:27:23 PM EST

explanation for why they want to censor others (but funny they never want to see themselves censored).

So you want to 'discourage' (take away my courage) me because I speak from a Christian perspective. No doubt you'd be all up in arms if someone discouraged one of your liberal protected groups.

And I don't doubt you have a fancy explanation for why you don't see this as a contradiction.

No problem, though, I take my courage from my faith in God, and the fact that atheist seek to discourage me is just more proof that I am on the Right side of things.

"No, I don't know that atheists should be considered as citizens, nor should they be considered as patriots. This is one nation under God."- George H.W. Bush
[ Parent ]

No, gay anti-global warming activists... (none / 0) (#249)
by Russell Dovey on Mon Apr 11, 2005 at 09:56:33 PM EST

...are just as fucking stupid as you, sellison. I have no political biases when it comes to scientific enquiry.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

sexual orientation? (none / 0) (#347)
by jcarnelian on Tue Apr 26, 2005 at 03:53:08 AM EST

What the hell does sexual orientation have to do with this, and why would you assume that "sellison", a flaming Christian if there ever was one, would be gay???

[ Parent ]
Read it again. (none / 0) (#348)
by Russell Dovey on Tue Apr 26, 2005 at 10:09:03 AM EST

"gay anti-global warming activists are just as stupid as you, sellison". Thus I imply that sellison is not a gay anti-global warming activist. (Incidentally, my grammar there is terrible, and it means I described someone who is gay, against the world, and in favour of warming in general.)

Sexual orientation has nothing to do with this. I'm mocking his right-wingness by tarring him with the same brush as other right-wing loonies have tarred themselves with.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

bad use of language (none / 0) (#349)
by jcarnelian on Tue Apr 26, 2005 at 03:05:36 PM EST

Sorry, I still don't get it.  I think it's best to avoid the term "gay" as part of any attempt to mock or insult anybody, just like you would avoid terms like "nigger" or "wop".

[ Parent ]
I wasn't insulting him with gay. (none / 0) (#350)
by Russell Dovey on Wed Apr 27, 2005 at 12:15:27 AM EST

The sexual orientation of the people I was contrasting with Sellison is irrelevant to the degree of insultitude he recie... you're trolling me, aren't you. Damn you for a brigand!

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

no, I'm not trolling you (none / 0) (#354)
by jcarnelian on Thu Apr 28, 2005 at 01:03:39 AM EST

I really still don't get what you were trying to say, and others probably don't either.  It's safer to avoid minority references if you don't want to risk offending people unintentionally.

[ Parent ]
Risk offending people unintentionally? (none / 0) (#355)
by Russell Dovey on Thu Apr 28, 2005 at 04:19:08 AM EST

If Gandhi had worried about offending people, he wouldn't have tried to overthrow the Raj.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

haha (none / 0) (#317)
by efexis on Mon Apr 18, 2005 at 12:21:13 PM EST

Are you serious???

So you want to 'discourage' (take away my courage) me

No, courage and encourage mean different things. 'Discourage' is the opposite of 'encourage', not 'courage'. Not to mention the fact that the discouragement is targetted at readers of the post, not the person who's already written the post.

On top of the fact that anything religion ("faith") based has no place in a scientific discussion, if you can't even get the language you're using right, what place do you have in a scientific discussion?

You may be willing to bet the lives of everyone on this planet on there being a "god that will protect us", but thankfully there are many of us not so blind ignorant to. We will save this world, even at the cost of saving people who actually believe what you claim to.

-2A

[ Parent ]
sorry, but the TRUTH is in (none / 0) (#346)
by jcarnelian on Tue Apr 26, 2005 at 03:30:53 AM EST

This is the same reason the 'global warming' 'debate' is such a fraud, scientists in the currently dominant pro-warming clique use every nasty little trick they can find to suppress their opponents,

There are no two viable sides to the debate anymore, the facts are in: global warming is a serious threat.

You yourself take a lot of absolutist positions, so you should understand the concept of "truth" and "no debate".  Unlike your absolutist positions, which are either wrong or based on faith, the global warming issue has been settled scientifically.

[ Parent ]

That's disappointing, sellison. (none / 1) (#248)
by Russell Dovey on Mon Apr 11, 2005 at 09:54:28 PM EST

Without your endorsement, Benford's Space Lens will never be built.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

why trust others and have less info? (1.00 / 3) (#185)
by chanio on Sat Apr 09, 2005 at 10:40:07 PM EST

You know, what's evil?
  • The power has always chosen to put the money on Nuclear power investigation instead of doing so with electromagnetism research. But the amount of time invested might have been the same.
  • There was a plan of using microwaves to transport electricity from several umbrella-satelites to provide the required electric power for all the world. What happened with that idea?

Isn't that last idea similar to puting a satelite to reduce the sun's heat? But the electric power would not be distributed to all the world, would it?

So, keep on voting Bush and his perhistoric friends. Go on. For the Earth, this is no more than a momentary cold.
________________
Farenheit Binman:
This worlds culture is throwing away-burning thousands of useful concepts because they don't fit in their commercial frame.
My chance of becoming intelligent!

Wrong (none / 0) (#253)
by Cat Huggles on Tue Apr 12, 2005 at 03:17:12 AM EST

The umbrella satellites you mention are simply another energy source and would give us sunlight that would not normally hit surface.

[ Parent ]
so? (2.50 / 2) (#193)
by CAIMLAS on Sun Apr 10, 2005 at 03:38:49 AM EST

This seems like a philosphical conflict amongst the "Captian Planet" group, as they also seem to be the same people behind things like, "Stop the Breeding" and limiting the world's population. These two issues seem to be diametrically opposed: if the earth gets warm, people will die, and the problem is solved. </sarcasm> That said, I'm not willing to believe that correlation is causation. I don't think it has anything to do with human-made output, and if it did, there's little (that is, nothing) we can do about it before its too late. The whole "the earth will cook" concept is based too entirely upon postulation and data models which have absolutely no way to verify. It's about as un-scientific as tarot cards. Just educate your children and make sure they're prepared to fight for food, protect their crops and family, and are not spineless wimps. If we shield the sun, it will result in many crops failing. We will effectively be reducing the land mass of the earth which can successfully grow crops, which would be the same as the initial problem.
--

Socialism and communism better explained by a psychologist than a political theorist.

not quite L1? (none / 0) (#215)
by dimaq on Mon Apr 11, 2005 at 03:04:34 AM EST

I wonder how the professor accounts for solar wind in his calculations - I guess the lense could be moved a bit closer to the sun to compensate...

Next question - when will the lens (presuming it's a solid flat object) accumulate enough dust to affect it's transparency, heating or position?

And finally - presumably the lens will build up electric charge, which can throw it away with the help of magnetic field of sun or earth - rather far fetched but still.

P.S. personally I'm in favour of hiring 3rd world nations to grow vegetable oil cheap enough to compete with mineral oil.

Good comments, thanks. (none / 0) (#250)
by Russell Dovey on Mon Apr 11, 2005 at 10:00:40 PM EST

And regarding vegetable oil: Yes, I think we should certainly help third-world countries get a head-start in what will become one of the twentieth-century's biggest industries, so they have some money for a change.

However, once rich nations figure that out, you'll see the same old protectionist bullshit coming out: we must protect our farmers by buying their grain at inflated prices, etc... Poverty-perpetuating lobbyist-inducing syphilitic buboes, the lot of them.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

20th century has ended (none / 1) (#301)
by skelter on Sat Apr 16, 2005 at 12:05:14 PM EST



[ Parent ]
clap fucking clap (none / 1) (#232)
by redrum on Mon Apr 11, 2005 at 12:32:33 PM EST

what age are you, twelve or something?

IAWTP (none / 0) (#263)
by undermyne on Tue Apr 12, 2005 at 12:15:40 PM EST




"I think you've confused a GMail invite with money and a huge cock." Th
[
Parent ]
look at his website. (none / 1) (#319)
by LUFT WAFFLE on Tue Apr 19, 2005 at 07:01:28 AM EST

comment spammer, that's all.
ANONYMISED
[ Parent ]
Er, not that simple? (none / 0) (#252)
by bjlhct on Tue Apr 12, 2005 at 01:28:45 AM EST

On the plus side, this might actually get cheap launch to space going.

However - why the hell are you using fresnel lenses - incredibly hard to make at that sort of scale - made out of plastic - inevitably degrading from solar radiation - instead of aluminum reflectors? What manufacturing processes are being used? What assumptions are he making about launch costs, anyway?

*
[kur0(or)5hin http://www.kuro5hin.org/intelligence] - drowning your sorrows in intellectualism

Global Warming & Climate Models (none / 0) (#255)
by mveloso on Tue Apr 12, 2005 at 03:42:48 AM EST

How is it that the global warming models can go out a few years or decades, when local, regional, and continental weather models can't look more than a week or two ahead?

Easy (none / 0) (#262)
by spiralx on Tue Apr 12, 2005 at 11:12:52 AM EST

Long-term models are actually easier to do as all of the messy chaotic stuff that plagues local, short-term models tends to cancel out over the long-term.

You're doomed, I'm doomed, we're all doomed for ice cream. - Bob Aboey
[ Parent ]

While this is true... (none / 0) (#291)
by masher on Fri Apr 15, 2005 at 01:44:10 PM EST

It fails to address the point that our long-term global models fail miserably at explaining the many warming and cooling trends in the earth's past.

[ Parent ]
Long-term vs Short-term prophecy (none / 0) (#272)
by Frank Anderson on Wed Apr 13, 2005 at 05:36:56 AM EST

Your question is answered by these lines from A Connecticut Yankee in King Arthur's Court:
Hank says:
"Yes, a genuine expert can always foretell a thing that is five hundred years away easier than he can a thing that`s only five hundred seconds off."
And the King replies:
"And yet in reason it should clearly be the other way; it should be five hundred times as easy to foretell the last as the first, for, indeed, it is so close by that one uninspired might almost see it. In truth, the law of prophecy doth contradict the likelihoods, most strangely making the difficult easy, and the easy difficult."
Incidentally, if anyone's interested I can predict the weather 5000 years from now to within a hundredth of a degree.

[ Parent ]
global warming predictions (none / 0) (#345)
by jcarnelian on Tue Apr 26, 2005 at 03:23:16 AM EST

Long-term global warming predictions aren't forecasts, they are showing possible developments, and there are many different models.

By itself, adding CO2 to the atmosphere will cause a increase in average global temperatures (that's simple physics).  While that would eventually become a problem, this basic effect is pretty modest. More complex climate models take into account various known or hypothesized feedback loops; those are the sources of predictions that there is the potential for much more rapid, catastrophic global warming. So, those models aren't saying "this will happen", they are basically saying "this is a plausible/possible/likely scenario".

Overall, there are enough plausible scenarios of catastrophic climate change to be seriously concerned and to be doing something about it.  Furthermore, because of the long half-life of CO2 in the atmosphere (1-2 centuries), by the time you can verify those models based on real measurements, you're already in deep trouble and it would keep getting worse for decades even if you stopped burning fossil fuels completely.

[ Parent ]

Weather vs Climate (none / 0) (#356)
by Mitheral on Thu Apr 28, 2005 at 12:10:08 PM EST

Because weather and climate are different things. I can say it's going to be hot and humid in Texas in August 2007 with winds out of the south and practically no one would call me out. That's climate. If I say it's going to be 37.7 degrees at 11:15AM on August 3rd, 2007 with 83.5% RH everyone would laugh becasue no one can predict that kind of thing. That's weather.

[ Parent ]
Nuclear is the way (none / 1) (#276)
by slashcart on Wed Apr 13, 2005 at 09:19:30 PM EST

for nuclear power to make enough of a difference to stop global warming by 2030, the world would have to replace the electrical output of one large coal-fired power station with an equivalent nuclear power station, EVERY DAY for the next 25 years. Every damn day. 365 per year.
I'm not sure about the above statistic. At present, 16% of the world's energy comes from 440 nuclear plants worldwide (world-nuclear.org). To replace the 60% of the world's energy that comes from fossil fuels would require an additional ~1700 nuclear plants, which would require building one plant every day for 4.5 years.

Of course, world energy needs will increase dramatically over the next few decades, requiring far more power plants. But if we already plan to build far more power plants, we may just as well build nuclear plants rather than coal plants. Granted, the initial costs of a nuclear plant are much higher than a coal plant, but the operating expenses are drastically lower.

Quite apart from the expense of building a new nuclear power station every day for 25 years [sic], there is not enough nuclear fuel on the planet to cope with the demand.
This is true for conventional nuclear reactors, which can only use Uranium-235 as fuel. But breeder reactors can use U238 as fuel which is 100x as plentiful, and which would last thousands of years even if 100% of the world's energy were generated from it. Various countries have already constructed large-scale breeder reactors, and have operated them commercially for years, generating electricity for millions of homes.

I've become a fervent believer that breeder reactors are the solution to essentially all current problems of electricity generation. They emit no air pollution or greenhouse gases whatsoever; they do not pollute the environment; they produce only a small fraction of the nuclear waste of conventional reactors; the nuclear waste they do produce has a half life of <100 years, not thousands of years; the fuel they use (Uranium-238) won't run out for thousands of years; they can easily avoid meltdowns using their superior liquid sodium coolant and newer (passive) safety technologies; and finally, the technology to build and operate them exists today.

Breeder reactors were cancelled because a few engineering glitches occured, over years of operation, that caused fires in one plant (not nuclear fires, just regular fires). This posed no danger of nuclear meltdown, since melting down a properly designed breeder reactor would be virtually impossible.

Breeder reactors were also cancelled because they're marginally more expensive to operate than other types of power plants. But they are much cheaper if you count the costs of environmental degredation and fuel depletion that plague the other methods of power generation in widespread use.

Of course, solar power and wind power would be excellent adjuncts. But they can be only adjuncts, since the power they generate is intermittent and modest.

16% is incorrect (none / 0) (#323)
by arthurpsmith on Tue Apr 19, 2005 at 10:44:46 PM EST

Actually nuclear provides only about 6% of world primary energy - the (typical) mistake you made was assuming nuclear's 16% of electricity represents everything. So multiply your 1700 by a factor of about 3, then another factor of 2 for expected growth in demand in coming decades, and you get about 10,000 reactors - well the quoted number in the article was slightly on the conservative side.

Actually, by 2050, some estimates see demand rising a factor of 4 (a level that likely could, barring global warming constraints, be supplied by coal) so we're talking 20,000 nuclear plants, or more than 1 added every day for the next 50 years.

Energy - our most critical problem; the solution may be in space.


[ Parent ]
-1 SciFi Masturbation (none / 0) (#281)
by Milo Minderbinder on Thu Apr 14, 2005 at 11:34:00 AM EST

Benford is on crack.
--
M & M ENTERPRISES, FINE FRUITS AND PRODUCE.
A little math (none / 0) (#295)
by Arkaein on Fri Apr 15, 2005 at 10:44:49 PM EST

Surface area of lens:
d = 1,000,000 meters ==> r = 500,000 meters
A = pi * r * r = 8x10^11 meters^2

Volume of lens:
w = 0.001 meters
V = A * r = 8x10^8 meters^3

Mass of lens:
p (density of plastic) = 1 gram / cm^3 = 1000 kg / m^3
M = V * p = 8x10^11 kg

Material lauch cost
c (cost per kg) = 10 USD
C = M * c = 8x10^12 USD

That's 8 trillion dollars US for the scientific notation impaired. These numbers are also quite optimistic, as they assume only 1 mm thickness lens, great reductions in cost of launching fixed mass, and a compact launch configuration for what will eventually be a very large, very thin object. The density of plastic may be a bit high, but not by a lot.

I must conclude that $10 billion, or even a $200 billion number I saw above in a comment, is a crock of shit.

----
The ultimate plays for Madden 2005

Truly amazing... (none / 0) (#298)
by masher on Sat Apr 16, 2005 at 01:25:48 AM EST

The ability people have to delude themselves is quite amazing at times.  You, for instance, have managed to convince yourself that a reasonable grasp of junior-high math and geometry allows you to discount a paper written by a Ph.D'd astrophysicist....without even having to read the paper itself!  Sir, I salute you.

Your mistake is simple. A plastic disk 1mm thick does *not* imply a 1mm disk of solid plastic.  Still don't understand?  Read his paper, and see.

Or just keep embarrassing yourself...your choice.

[ Parent ]

Don't like my numbers? Show me better ones. (none / 0) (#299)
by Arkaein on Sat Apr 16, 2005 at 01:53:52 AM EST

The only paper I could find (there was none linked in the article) was this one, which only discusses the subject for a few paragraphs. If you want me to read a more detailed article I suggest you provide a link so I can partake in this brilliant physicist's wisdom.

And by the way, that section (it's right near the end) said a 2000 km diameter lens, not a 1000 km diameter one like I used in my calculations, so you can multiply my estimated cost by a factor of 4.

And you say the lens is not solid, well exactly how much do you think you can hollow out a plastic fresnel lens that's only 1 mm think to start with? Because you'd need to remove approximately 99.9% of the material to get the launch weight costs down the around the $10 billion mark.

----
The ultimate plays for Madden 2005
[ Parent ]

Note that the lens is 10 µm thick, not 1 mm. (none / 0) (#300)
by Another Scott on Sat Apr 16, 2005 at 10:45:29 AM EST

As cited in Fig. 3(C) in the .PDF you linked:

10 µm thick Fresnel lens near L1

It changes the mass calculations a little bit ;-), but it seems to be an impractical solution either way. For example, this paper from Lawrence Livermore says:

Geoengineering schemes impose a variety of technical, environmental and economic challenges (Early, 1989; Seifritz, 1989; National Academy of Sciences, 1992; Watson et al., 1995; Flannery et al., 1997; Teller et al., 1997). For instance, in the case of placing reflectors in space, since a quadrupling of CO2 requires the interception of about 3.6% of the sunlight incident on the Earth, an interception area of ~4.6x10^6 km^2 or a disk of roughly 1200 km in radius has to be built. To counteract a transient warming, the solar input has to diminish over time as CO2 increases. If CO2 increases at the current rate of ~0.4% year^-1 (Houghton et al., 1995), to counteract this warming, we would need to build ~1.2x10^4 km^2 of interception area each year. Other options also involve great difficulties. Placing small particles or aerosols in the stratosphere may not result in uniform diminution of radiation. Mirrors in low Earth orbit will lead to flickering of the Sun ~4% of the time, and involves tracking problems so that mirrors do not collide with each other. Reflectors or scatterers at the Lagrange point between the Sun and Earth involve large costs. Ecosystems would be impacted by changes in atmospheric CO2 content and photosynthetically active radiation, even without climate change.

The failure of a geoengineering system could subject the Earth to extremely rapid warming. Ethical and political concerns differ depending on whether global-scale climate modification is intentional (e.g. geoengineering) or merely a predictable consequence (e.g. fossil fuel burning) of our actions. Many of the geoengineering schemes are cooperative solutions that require continuous world management for multiple centuries. Given the history of noncooperation at a global scale just in the 20th century, there is very high probability of the nonfeasibility of geoengineering of cooperative solutions (Schneider, 2001).

The original paper that everyone cites that discusses the Fresnel lens at L1 is:

J. T. Early, J. Br. Interplanet. Soc. 42, 567 (1989).

I haven't found a free link to it.

Hey Russell there's a lesson here: Including numbers from and cites to the original claims helps to minimize confusion like this. ;-)

Cheers,
Scott.

[ Parent ]

So it does (none / 0) (#302)
by masher on Sat Apr 16, 2005 at 09:35:20 PM EST

It changes the mass calculations a little bit ;-), Aye, so it does..by a factor of 1/100. Also, the estimation of the plastic's density at 1g/mm^3 is quite high, given that's as dense as water. While some plastics are even denser than water, an advanced lightweight polymer would be expected to be considerably less.

Finally, I note that this paper raises the possiblity of manufacture from lunar materials which is-- once you've amortized the cost of a mass driver launch system-- nearly free.

[ Parent ]
My bad (none / 0) (#304)
by Arkaein on Sat Apr 16, 2005 at 10:44:08 PM EST

Not sure how I missed that 10 micron number, I must have been tired. That would knock my $8 trillion estimate down to $80 billion.

As far as the plastic density, I just threw a rough estimate in there based on some common plastics. Certainly lighter onces could be made, to keep things simple we could say 0.25 grams / cc to balance out the factor of 4 error in area calculation. That still leaves about a factor of 8 difference between my estimate and the $10 billion in the K5 writeup.

A mass driver system would be sensible, and lunar manufacture would certainly reduce launch costs, but the writeup specifically said the costs could be achieved using today's technology. Obviously we don't have either mass drive launchers or lunar manufacturing facilities, so I don't think we can discount the relevant bootstrapping costs in the budget for such a project.

----
The ultimate plays for Madden 2005
[ Parent ]

Getting closer... (none / 0) (#305)
by masher on Sat Apr 16, 2005 at 11:23:07 PM EST

"...but the writeup specifically said the costs could be achieved using today's technology. Obviously we don't have either mass drive launchers or lunar manufacturing facilities..."

We don't have VW Microbuses in Antarctica either...but with today's technology, we could have them if we wanted.

We've built mass drivers for decades. They're not yet practical for terrestrial launch systems, as they've all been limited to around a 5km/s exit velocity (faster than that and the rails fuse/vaporize/spontaneously combust). But the lunar escape velcity is considerably lower than this, so we can safely say we've already built lunar mass drivers...we just failed to install them in the proper place. :)

Similarly, there's nothing miraculous required for lunar manufacturing. Cost-effective manufacturing of goods or materials designed to be shipped to earth would require some technological advances, but simple regolith refining is 1970s-era tech.

In closing, I want to point out that Benford may not be postulating lunar materials at all. I know Teller's approach was strictly limited to terrestrial manufacturing.

[ Parent ]
I wish I'd found that when I looked. (none / 0) (#330)
by Russell Dovey on Wed Apr 20, 2005 at 03:28:37 PM EST

Thanks a billion, mate. Yes, the paper should be free online. It's a shame that the thriving bookz community isn't as interested in ripping off Science as they are in ripping off J.K. Rowling.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

All the links you could want (none / 0) (#303)
by masher on Sat Apr 16, 2005 at 10:40:19 PM EST

Benford didn't originate this idea; it's been researched in depth by a large number of scientists, with some proposals dating back as much as 15-20 years.  

Here's a paper by Ed Teller (father of the hydrogen bomb, if you didn't know) of a scattering system at L1.  He estimates the total mass required as 3x10^3 metric tons.

http://www.llnl.gov/global-warm/231636.pdf

Another paper by Dr. James Early of Lawrence Livermore, titled "Space-based solar shield to offset greenhouse effect".  Early's mass estimate is considerably higher than Benford's...but he's proposing a lens comprised of glass formed from lunar rockmelt, not plastic.  

http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1989JBIS...42..567E&db_key=AST

Finally, here's a paper (presented at the 53rd International Astronautical Congress) contrasting some of the approaches, along with the total mass in orbit required for each.

http://www.star-tech-inc.com/papers/earth_rings/earth_rings.pdf

[ Parent ]

nucleus of an idea there (none / 0) (#308)
by jcarnelian on Sun Apr 17, 2005 at 11:41:02 PM EST

There is no reason for this thing to be a lens, which makes me wonder how serious the whole thing is at all.  The comments about "financial self interest" also make me wonder, because that's the bullshit we usually hear from global warming deniers.

However, there is a nucleus of an idea there: by placing something at the L1 point, one might be able to reduce solar radiation.   A thin, partially reflective gold foil might be a feasible choice.  Or something that is more fully reflective but only 1% of the total size (casting a shadow, obviously).  Great quantities of dust might be another (if only we could just pump the output from our power plants right to the L1 point).

Some basic physics. (none / 0) (#309)
by masher on Mon Apr 18, 2005 at 01:00:00 AM EST

> "There is no reason for this thing to be a lens..."

A topic already covered in painstaking detail here.  A reflective object is subject to light pressure from the solar radiation impinging upon it.  A thin gold film as you propose would require a massive amount of energy-- constantly applied-- simply to hold it in position.  A nonreflective object less so, but still totally infeasible.  A diffractive object which doesn't absorb or reflect photons, but merely imparts a small angular deflection, incurs only a tiny fraction of this force.

> "Great quantities of dust might be another..."

Keyword: great.  This is another idea that has been analyzed in depth.  Unfortunately, unless you already have the dust nearby ('near' in terms of dV, not distance), the diffractive approach is far cheaper.  

> "if only we could just pump the output from our power plants right to the L1 point..."

We can easily do this-- just build those plants in space to start with.  Too bad environmentalists are against the very technologies which would enable us to do this.


[ Parent ]

Damn right; more Orion pusherplates for everyone! (none / 0) (#331)
by Russell Dovey on Wed Apr 20, 2005 at 03:32:48 PM EST

It's certainly the best way I can think of to get rid of America's aging nuclear stockpile; throw it under a fleet of giant spaceships as propulsion.

Of course, there might be a TAD too much fallout for some people. But the nuke tests already performed didn't put that much into the atmosphere, if you think about it.

"Blessed are the cracked, for they let in the light." - Spike Milligan
[ Parent ]

basic physics indeed (none / 0) (#337)
by jcarnelian on Sun Apr 24, 2005 at 11:26:26 AM EST

A reflective object is subject to light pressure from the solar radiation impinging upon it. A thin gold film as you propose would require a massive amount of energy-- constantly applied-- simply to hold it in position.

False.  Mirrors can be kept in a wide range of orbits without boosters by balancing radiation pressure against gravity.  You can keep them permantly in a position between the sun and earth (even at positions other than L1).

That alone makes them a far better choice in this application, compared to a Fresnel lens, which doesn't give you that level of control.

We can easily do this-- just build those plants in space to start with.  Too bad environmentalists are against the very technologies which would enable us to do this.

Building power plants in space won't help us with the CO2 already in our atmosphere.  And given the cost of lifting stuff into space, it is also completely infeasible.

[ Parent ]

basic physics indeed (none / 0) (#338)
by jcarnelian on Sun Apr 24, 2005 at 11:55:50 AM EST

A reflective object is subject to light pressure from the solar radiation impinging upon it. A thin gold film as you propose would require a massive amount of energy-- constantly applied-- simply to hold it in position.

Quite the opposite: a collection of mirrors like that would be essentially a fleet of solar sails.  They can easily stay in position between the sun and the earth, even at positions far away from the L1 point, without any boosters.  

A back-of-the-envelope calculation suggests you need around 10000 m^3 of Aluminum to build the sails, or about 27000 tons (for comparison, annual production in 1999 was 24 million tons).  That's 1000 launches with today's technology, a massive undertaking, but certainly quite feasible if we wanted to do it.

We can easily do this-- just build those plants in space to start with.  Too bad environmentalists are against the very technologies which would enable us to do this.

Building power plants in space won't help us with the CO2 already in our atmosphere.  And given the cost of lifting stuff into space, it is also completely infeasible.

[ Parent ]

Oops, time for a new envelope... (none / 0) (#339)
by masher on Sun Apr 24, 2005 at 02:31:34 PM EST

"Mirrors can be kept in a wide range of orbits without boosters by balancing radiation pressure against gravity...A back-of-the-envelope calculation suggests ..."

Without getting into the details of Lagrangian mechanics, I think I can explain this so you understand your mistake. At L1, the sun's gravity is *already* being balanced by terran gravity. Light pressure adds an additional term, an outward-pointing radial vector. For a large, low-mass object, that vector predominates. The new stasis point? On the FAR side of the earth, where terran and solar gravity both combine to counteract it. A very inconvenient place to block sunlight reaching the earth's surface.

Your notion that there exist a huge number of stasis points between the earth and sun is totally incorrect. Even if you assume an object massive enough to keep light pressure from predominating, you then wind up with a stable solar orbit that doesn't synch with the earth's orbit. Result? An object that doesn't move further away from the sun...but it doesn't lie between the earth and the sun either, except for a brief "eclipse" once per orbit.

"Building power plants in space won't help us with the CO2 already in our atmosphere..."

Why of course it will. Do you not realize that a variety of CO2 sinks are in constant operation around the globe? Its not the absolute level thats a problem, its the source rate exceeding the sink rate. Remove CO2 sources, and the level declines on its own.

[ Parent ]
my envelope is just fine, thank you very much (none / 0) (#340)
by jcarnelian on Sun Apr 24, 2005 at 10:05:28 PM EST

Light pressure adds an additional term, an outward-pointing radial vector

It need not be radial (or even constant in time)--it depends on the orientation of the solar sail.  There are all sorts of nifty things you can do with solar sails.  A stationary solar sail is called a "statite". Here is a simple explanation.

Do you not realize that a variety of CO2 sinks are in constant operation around the globe? Its not the absolute level thats a problem, its the source rate exceeding the sink rate. Remove CO2 sources, and the level declines on its own.

Unfortunately, the half life of CO2 in the atmosphere is of the order of 1-2 centuries.  Furthermore, even if we stopped all man-made CO2 production completely, temperatures would likely continue going up for decades anyway.  That's why carbon emissions are so dangerous--there is nothing we can do to remove them once they are in the atmosphere.

[ Parent ]

Are you really so dense? (none / 0) (#341)
by masher on Mon Apr 25, 2005 at 01:15:07 PM EST

There are all sorts of nifty things you can do with solar sails. A stationary solar sail is called a "statite"....

Look, its pretty simple. Any object in orbit is already balancing gravity by centripedal acceleration. A solar sail balancing gravity by light pressure isn't in orbit. It's stationary...a fact you yourself point out but fail to grasp the significance of.

Now, pray tell us how a stationary object can continually block the sun's light from an orbiting earth? See your mistake yet?

"Furthermore, even if we stopped all man-made CO2 production completely, temperatures would likely continue going up for decades anyway...."

Not if we reduce solar forcing by the method described in this article. Shading the earth cools it...a concept simple enough I hope even you can grasp.

[ Parent ]
your previous comments speak for themselves (none / 0) (#342)
by jcarnelian on Mon Apr 25, 2005 at 03:18:02 PM EST

A solar sail balancing gravity by light pressure isn't in orbit

Quite right: a solar sail wouldn't be in orbit--it would be a spacecraft with an inexhaustible propulsion system.  That's why it can follow many trajectories that aren't orbits; for example, it can permanently stay between the earth and the sun at points other than L1.  That's what makes it useful in this application.  If you follow the links, it explains how it works.

I don't have anything else to say; your parent posts speak for themselves.  I suggest you follow the links and read up on this stuff.

[ Parent ]

Apparently they don't (none / 0) (#343)
by masher on Mon Apr 25, 2005 at 05:12:56 PM EST

I realize my coursework in undergraduate and graduate-level classical mechanics mean nothing to a chap smart enough to read an article on "answers.com". Similarly, the opinions of Benford and a dozen-odd other Ph.Ds who have proposed similar L1-based shields are likewise to be ignored...but I'm going to take a final stab at trying to explain this to you. The information is there even in the link you posted-- you just have to be able to understand what you read. From your link, an object with a mass-to-surface area ratio of 0.8g m-2 receives radiation pressure equal to solar gravity. Not said but what should be obvious is such pressure is received only if the object is normal to the radiation vector...directly facing the sun. If it cants, it receives a correspondingly smaller force. Our solar shield is considerably below this figure, and thus would generate more light pressure than gravity. Such an object can indeed travel to any point in the solar system, or beyond in theory...with the appropriate set of maneuvers. Once it arrives at one of those points, though, if it wishes to REMAIN there, it needs to seek stasis. And it can only do that by canting to lower the area it presents to the sun. And, of course, if it does that, it blocks a correspondingly smaller amount of solar radiation from whatever is behind it. The situation is actually far worse. Imagine trying to balance an object on the earth-sun line at any point closer to the earth than L1. If you're trying to stay on that line, you have the same angular velocity as L1 (or the earth), but since you're further away than L1, your linear velocity is higher and so is your centripedal force. You're closer to the earth, so terran gravity is stronger...and solar gravity is weaker. You've therefore increased two vectors that point outward, and decreased one vector that points inward. All three of those effects need a corresponding vector to balance them...a vector that in all three cases points inward. Solar pressure, however, has the wrong sign. Conclusion-- you cannot in any possible manner use it to reach an equilibrium state. Its slightly more optimistic for points nearer the sun. But move significantly closer than L1, and terran gravity quickly becomes insignificant. Without getting into the lagrangian mechanics of the manuevers required for station-keeping here, it means you spend essentially zero time where you actually want to be...you follow a lissajous pattern around the actual stasis point. Furthermore-- you can only do this for objects whose mass is **greater** than the before-mentioned ratio. Which our shield is not...not unless we want to spend 25X as much money to make it purposefully more massive than needed. There's several other problems that are difficult to describe on a non-mathematical basis...but if you cannot understand the simple objections, there is surely no point in describing any of the others.

[ Parent ]
getting better... (none / 1) (#344)
by jcarnelian on Tue Apr 26, 2005 at 02:59:12 AM EST

Once it arrives at one of those points, though, if it wishes to REMAIN there, it needs to seek stasis. And it can only do that by canting to lower the area it presents to the sun. And, of course, if it does that, it blocks a correspondingly smaller amount of solar radiation from whatever is behind it

Yes, that was clear to me; it's good that you see it, too.  What is not obvious is what "correspondingly" actually means.  You do seem to realize that the actual angle of the solar sail may depend on the distance from the sun, but perhaps  not enough to make a useful difference.  But the amount of radiation that is blocked when the solar sail remains fixed at a location is also dependent on its distance from the sun, both because of geometry and because of the way the solar sail works.  Ultimately, one just has to work out all the different factors; hand-waving qualitative arguments about "centripedal forces" are not going to do the trick.  

Furthermore, there are other possible engineering approaches once you have navigable structures.  For example, a fleet of solar sails lets you pick up mass along the way and tether it--finding non-manufactured mass in the solar system is not hard.

I realize my coursework in undergraduate and graduate-level classical mechanics mean nothing to a chap smart enough to read an article on "answers.com".

I just picked an article that illustrated the point well and in its simplest form--that solar sails can stay in position between the earth and the sun, a point you had apparently previously disputed.  I see nothing wrong with picking a factually correct, easy to read web page that illustrates the point I wanted to make.

Let me state clearly again: I'm not saying that solar sails will work, I'm saying that if anything is going to work, it's likely going to be solar sails.  It's clear we have the technology to manufacture enough area and launch them, and they are powerful and navigable, none of which can be said for a Fresnel lens.  That doesn't mean you just fly a bunch of solar sails into position and you are done.  That's why I said "there is a nucleus of an idea there".

And a piece of advice, more important than any Lagrangian mechanics you may have learned: a better response to what you perceive to be a technical problem is not "that won't work, you're stupid, and I'm so smart", it's "that sounds interesting, but have you thought about the following problem".  It makes discussions far more productive, and you might even learn something.

[ Parent ]

Returning the favor. (none / 0) (#357)
by masher on Fri Apr 29, 2005 at 01:14:47 AM EST

a piece of advice...a better response to what you perceive to be a technical problem is not "that won't work, you're stupid, and I'm so smart"...

Quite right; my patience level in explaining a concept multiple times certainly leaves something to be desired.

A bit of advice for you in return...when you realize you're wrong, its best to just admit it, instead of trying to defend an increasingly ridiculous position. I suspect that you actually realized your error several posts ago, and simply didn't wish to admit it.

"What is not obvious is what "correspondingly" actually means...the actual angle of the solar sail may depend on the distance from the sun, but perhaps not enough to make a useful difference..."


Actually, it is obvious. Canting a solar sail reduces incident radiation pressure by a cos(theta) term. However, it also reduces the amount of sunlight blocked by the exact same factor, meaning a corresponding reduction in the efficiency of the shield.

Do you realize the implication? Canting is NOT a feasible strategy for a solar shield in a stasis. Canting at a 60 degree angle would cut light pressure in half, and simultaneously block only half the light. Effectively, you now have a shield half the size but twice as dense....and costs are linear with density.

Canting is useful for manuevering, or when you're not concerned with intercepting light. But for a solar shield, you're trying to maximize incident surface area per unit mass...the exact factors that maximize thrust. I'll work out the actual math for you, but I am honestly hoping you can grasp this conceptually without it.

"Ultimately, one just has to work out all the different factors; hand-waving qualitative arguments about "centripedal forces" are not going to do the trick...."


One thing physics students are well-taught is the vast number of times in which one does not "have to work out all the factors". Many times a qualititative approach will answer whether something is possible, without quantitative figures. In this case, it allows to quickly realize that a solar sail cannot be stable at any point closer to the earth than L1. Such a move increases the sum of outward-directed forces and decreases the only inward-directed one. Two positive numbers cannot be added to equal zero...you don't need to calculate the exact figures to disprove it. For points closer to the sun than L1 a more quantitative approach is needed. I'll put the math in the next post.

"I just picked an article that illustrated the point well and in its simplest form--that solar sails can stay in position between the earth and the sun...


But your article said no such thing; you simply misunderstood the meaning of "stasis" in this context.

"For example, a fleet of solar sails lets you pick up mass along the way and tether it..."


Quite true...however using a fleet of solar sails to push a massive object(s) to L1 isn't the same thing as a solar sail itself acting as a shield. The first is feasible; the second is not. And even still, a fresnel lens is a far simpler approach than sailing off to find a large meteor, attaching to it in some manner, then maneuvering to L1. For one thing, the thrust imparted to a massive object would be so low the project would take decades. And you'd need a separate manned mission to perform the coupling...autonomous manuevers are fine in theory, but we're a ways from being able to pull off one that complex.

[ Parent ]
massive objects (none / 0) (#367)
by jcarnelian on Thu May 05, 2005 at 11:42:20 AM EST

Quite true...however using a fleet of solar sails to push a massive object(s) to L1 isn't the same thing as a solar sail itself acting as a shield

No, you use the sails as the shield and the massive object as an anchor, to bring the total to around 1.6g/m^2.  And it shouldn't end up anywhere near L1 (that would defeat the purpose of using it as an anchor).  Furthermore, you don't have to do this with one big mass, you can do it with lots of little masses.

[ Parent ]

The math... (none / 0) (#358)
by masher on Fri Apr 29, 2005 at 01:48:10 AM EST

For an object in orbit (or any central-forces problem), centripetal force must equal gravitational force. Assuming one body is substantially more massive than the other, the equation is:

GMm
----- = mrw2
  r2

Where w (omega) is the orbiting object's _angular_ velocity (2pi/period). For our solar sail, we have to add a term to the cetripetal side that equals the light pressure on the object. For now, lets call it CA/r^2, where C is the solar constant of light, A is the area incident to the radiation, and r the orbital radius:

GMm
----- = mrw2 + CAr2
  r2

Now the fun starts. For an object to remain on the earth-sun line, it has to have the same angular velocity of the earth. That means we can solve the above equation for the angular velocity squared, and equate it to the similar expression for that of the earth's:

GMmsail - AC     GM
-------------- = --------
   rsail3msail      rearth3

We can do standard algebraic simplication...we can also do a few substitutitions to save a lot of work (a smart physicist is a lazy physicist). First of all, lets express the radius of the earth's orbit- r(earth)- in A.U. That lets us put a 1 there...and lets us express the sail's orbital radius as a fraction of an A.U....a lot easier to work with than km. Also, lets remember that Area*Thickness = volume...and volume/density = mass. That means we can substitute d/T (area density) for A/m. Finally we can remove the need to actually calculate C, the solar constant by remembering that an object of 1.6g/m^2 (or 0.8 for absorptive sails) balances light pressure against solar gravity. So we can express C in terms of areal density, G, and M (solar mass), and eliminate it from the equation totally. Rearranging and simplifying, we now get a very nice result:

rsail= 1 - 1.6/(dareal)


[ Parent ]
The math (part 2) (none / 0) (#359)
by masher on Fri Apr 29, 2005 at 02:18:12 AM EST

So we now have the orbital radius of any solar sail matching the earth's period of rotation, expressed in terms of its areal density, as a fraction of the 1.6 g/m^2 "magic value" needed to balance it in a static, nonorbital configuration.

Lets look at some of the interesting results of this equation. An infinite (or any very large) density gives us a radius of 1...in other words, any object so dense that you can ignore light pressure orbits at the speed the earth does only with a radius of 1 AU...duh. Still, nice to know we did the math correctly.

For a density of 1.6, the right side of the equation vanishes, giving us a radius of zero. In other words, a "stator" sail can lie on the earth-sun line only at the direct center of the sun. An obvious result (since a stator cannot be orbiting or the centripetal acceleration would cause forces to not balance). But again, nice to know the math is right.

Also, for any density LESS than 1.6, the right side becomes negative. The only solutions are therefore negative radii...non real-world solutions, proving that an object less dense than this cannot remain in orbit anywhere.

Now, lets look at some quantitative figures. Assume a shield twice as dense as the minimum, that gives us a radius of .79 AU. That's 21 times further away than L1. So for it to subtend the same angle, it has to be 21X as large, or have 441 TIMES the area. Ooops...not feasible. An object less dense would be even further away...so lets try something denser. How about something ten times as dense? That gets us to 0.965 AU. Thats only 3.5X as far away as L1, or meaning a shield thats 12 times the area...as well as 10 times denser than our 1.6g threshold value.

You can work out more figures yourself if you wish, but even you should be able to see the asymptotic behavior. Required density quickly becomes unreachable for points close to L1...and further away, the size of the object required is prohibitive. Worse, for points anywhere near L1, you can't ignore the earth's gravity from the analysis. I can't show you an easy derivation with it without using something like a Hamiltonian, but trust me-- it makes the situation much, much worse. The outward force acts to increase the required density, a density that becomes infinite as you come within 1M kilometers of the earth...something you should be able to intuitively realize based on the fact L1 is stable without light pressure.

I took a few shortcuts in this analysis. I assumed circular orbits for one, but elliptic orbits doesn't change the nature of the equations. If you don't believe me, you're welcome to work it out yourself. Its a good exercise in basic central-force problems...and doing it will teach you far more than reading a post will do.

[ Parent ]
take your own words to heart (none / 0) (#366)
by jcarnelian on Thu May 05, 2005 at 11:30:07 AM EST

I suspect that you actually realized your error several posts ago, and simply didn't wish to admit it.

Actually, in my original posting, I merely pointed out that a Fresnel lens is not a feasible solution because there is no material we could make it from. But we can manufacture, launch, and navigate thin metal film structures into place with an area that is of the right order of magnitude.  How to keep them there is another question.

You keep repeating the same argument over and over again, that a shiny mirror pointed straight back into the sun will have to weight at least 1.6g/m^2 (or proportionally more if it's canted); that's obvious and beyond dispute.  Your blind spot is that you seem to think that that's the only case to consider.

There are lots of other possibilities once we realize that we can manufacture mirrors this large.  The Fresnel lens idea is to deflect light slightly, instead of reflecting it straight back.  That's a good idea in principle (it reduces radiation pressure relative to reflecting straight back), but a Fresnel lens just isn't a feasible choice.  However, we can manufacture optically similar arrangements of linked mirrors (think telescope) that experiences only a fraction of the radiation pressure and deflect all the light falling on them around the earth.  Or we can tether the sails to an asteroid.  And there are probably lots of other possibilities I haven't thought of.

One thing physics students are well-taught is the vast number of times in which one does not "have to work out all the factors".

Well, I think you just provided us with another demonstration of why we don't give engineering licenses to physicists.

[ Parent ]

Failed the math quiz eh? (none / 0) (#368)
by masher on Thu May 05, 2005 at 01:27:00 PM EST

You keep repeating the same argument over and over again, that a shiny mirror pointed straight back into the sun will have to weight at least 1.6g/m^2

Did you even read the proof? You don't even state the argument properly, much less rebut it.

No, you use the sails as the shield and the massive object as an anchor, to bring the total to around 1.6g/m^2.

A reflective object of this mass is capable of remaining on the earth-sun line at only one point-- the center of the sun itself. As I already proved. Below this critical mass, it's stable nowhere. And above this mass, its stable at many points...but all of them so far from the earth as to require a prohibitively large surface area to have any effect as a solar shield.

The proof is all there n in black and white. Use a little skull sweat and read the figures...I purposefully didn't use any math above the high school level. It's not difficult to comprehend.

we can manufacture optically similar arrangements of linked mirrors...that experiences only a fraction of the radiation pressure and deflect all the light falling on them

Ever hear of conservation of momentum? Your statement reflects a basic misunderstanding of it. A mirror will receive a ΔP equivalent to the change in momentum of a reflected photon. A small delta means requires a small deflection. A fresnel lens can do this and remain normal (perpendicular) to the earth-sun line...a mirror can only do this by increasing the angle of incidence. That reduces the applied momentum by a cos(θ) term, but it also increases the required mirror area by a tan(θ) term. It just doesn't work, sorry.

I think you just provided us with another demonstration of why we don't give engineering licenses to physicists...

Actually, I have a PE license in two states and one foreign nation. As a physicist, I'm a failure, however, having never completed my postgraduate degree. That's why when working physicists like Ed Teller and Greg Benford say its possible, I tend to listen.

Who do you listen to? The guy down at the local car wash?

[ Parent ]
what a one-track mind (none / 0) (#369)
by jcarnelian on Thu May 05, 2005 at 05:12:46 PM EST

.a mirror can only do this by increasing the angle of incidence.

That's not the only way.  You can also use two mechanically linked, curved, approximately parallel mirrors in an arrangement similar to a mirror telescope.  The total deflection of light is small, and hence the transfer of momentum.

A mirror will receive a ΔP equivalent to the change in momentum of a reflected photon.

If we return to single mirror arrangements, if that mirror is tethered to a rock of the right size, then that will be enough to balance solar gravity where we want it to be.  That's another design possibility.

Did you even read the proof? You don't even state the argument properly, much less rebut it.

There is nothing to rebut: your analysis is correct for a single mirror with uniform mass per area.  You simply fail to consider that there are lots of other possible designs.  (Your statements about Fresnel lenses are incorrect, and your analysis doesn't work near the sun, but who's counting.)

Actually, I have a PE license in two states and one foreign nation.

Scary if true.

[ Parent ]

Lol, nice try Einstein. (none / 0) (#370)
by masher on Thu May 05, 2005 at 10:38:55 PM EST

Well this suggestion isn't quite as bad as your last, which was on the order of perpetual motion, it still fails utterly, for a dozen different reasons, each sufficient in itself.  

I assume you're speaking a some sort of Newtonian reflector configuration, with the secondary canted slightly for deflection.  I'll explain why we could never build such a thing today...and even if we could, a thin sheet of corrugated plastic (aka a fresnel lens) would be a thousand, thousand times cheaper, simpler, and more foolproof.

First: radiation pressure isn't wholly cancelled.  No mirror is a perfect reflector...a thin film-based mirror is going to absorb or pass several percent of incident light.  And gain momentum from all of it.   Also, the secondary reflector will reflect on its face...but its nonreflective rear is facing the sun, and will absorb 100% of the radiation on it..  The secondary can be smaller, but not by a huge margin, as this would increase the light intensity to the point of catastrophic mirror failure.  (As an exercise for the reader, I'll let you work out why you can't make the secondary backside reflective, and daisy-chain a tertiary mirror above it to cancel that force)  Probably 1/5 the size is as small as you can safely get...meaning you'll generate at least 23-28% of the total light pressure, depending on how perfect your mirror is.  

Furthermore, you either need a hole in your primary close to the size of your secondary (making it 20% larger as well) or you need your secondary's focal point to be dangerously close to the primary itself...a nightmare if alignment ever slips slightly.  

Second: optics.  A diffusive fresnel lens requires less precision than any optical device we can make.  It doesn't need a specific overall shape (flat is nice, but not required) and no section needs a specific fixed position with respect to others.  Its essentially just a large collection of independent, very thin prisms.  But a parabolic mirror has very rigid requirements.  Even if you don't require a focused image, the mirror needs to be perfectly symmetric in two axes, or unbalanced light pressure will generate a rotational torque.  It needs to be curved sharply (we'll see why a gentle curve doesn't work later on), and held rididly in that shape by its own structural integrity.   Finally, unlike the fresnel, it has to be pointed directly at the sun at all times...again, we'll see why later.

Our fresnel lens doesn't even need enough stiffness to support its own mass...we can put a very gentle spin on it to keep it flat.  But these mirrors need to be strong enough to hold a very specific shape...without flexing, and against incredibly massive forces.  How massive?  That leads us to the next section.

Three: coupling forces.  Even though force on the primary and secondary mirrors (nearly) cancels out, the linkage between the two has to be able to withstand the entire force.  The struts connecting the two mirrors are what actually allow force A to counteract force B.  For a point anywhere near L1, the total force is going to be roughly 1.25 million metric *tons*.   Closer to the sun, it'll be even greater.

Wait, the force issue gets much worse.  How long do these struts need to be?  A standard parabolic mirror has a focal ratio of f/4 to f/12.  The shorter the f/ratio the harder the mirror is to make, focus, and align accurately...thats why non-cadiotropic telescopes are so long and skinny.  I'll be an optimist and suggest we could manufacture a mirror this size with an f/3 ratio.  Given the aperature of 1000 km, we need struts (1K*3*4/5)= 2400 km long.

Now if you know anything about statics, you know the force a beam/strut/pillar needs to support is only half the equation.  The other half is its length...the longer the strut, the stronger it needs to be for a given force.  Still worse is the fact the secondary mirror is smaller, so the struts will be canted inward, and experience enormous lateral forces.  

Furthermore, even if we could build such struts with modern day technology, they don't "cancel" force; they merely transfer it. Which means the two mirrors each need to be stiff enough to absorb that force without breaking...or even without the slightest flexing which would throw off alignment and generate even more force.

I suppose one day we could build such a structure, if we used solid carbon-fiber struts, honeycombed heavily with side and internal bracing all the way up.  But this century?  That's science fiction.

Four. Structural Integrity.  Unlike the fresnel lens which is under nearly no internal stress, this object is highly loaded.  Since a structural failure would cause it to tear itself apart, it has to be massively overbuilt as a precautionary measure.  And still, you have the worry of a stray meteor.  A rock that would simply tear a 100 meter hole in a fresnel lens could easily destroy enough structural integrity to cause flexing or movement of one of the mirrors.  That causes further unbalanced forces, and catastrophic failure.

Five. Station Keeping.  If the shield moves ever-so-slightly away from an exact perpendicular angle to the sun, some of the incident light on the primary will no longer be intercept the secondary.  That generates a torque causing further rotation and pulling it even further out of alignment...and also pushing it into a higher orbit from radiation pressure.

I could go on quite a while, but I doubt the facts are going to persuade you at this point.  Even if you're myopic enough to believe we could even build such a thing, you should realize it would be so massive as to not be any sort of "solar sail" at all, no more than the space shuttle is, simply because it has shiny skin.  

[ Parent ]

you're thinking, that's good (none / 0) (#371)
by jcarnelian on Fri May 06, 2005 at 03:56:35 AM EST

Well this suggestion isn't quite as bad as your last, which was on the order of perpetual motion, it still fails utterly, for a dozen different reasons, each sufficient in itself.

The only suggestion I made was that mirrors are a better choice than Fresnel lenses.  After that, I was countering a series of ridiculous non-existence claims from you, like that mirrors can't stay on the earth-sun axis, that they can't stay inside the orbit of the earth, etc.

So, whatever mass, absorption, and other requirements may exist are far easier to satisfy using that technology, and it's the only surface that we can manufacture with sufficient area with technology available in the near future.

Your analysis of the problems with arrangements of mirrors is partly right: they aren't perfectly reflective, there is backside reflection, etc.  All of that is obvious.  There may or may not be ways of engineering around that (I can think of some).  Keeping solar sails light yet in the correct shape is a standard engineering problem.  It's tricky, and not just for the reasons you mention, but probably solvable; it does not, however, require stiff or rigid mirrors.

What you keep missing is that Fresnel lenses have analogous problem: they are also subject to intrinsic radiation pressure (variable over their surface) and they are not completely transparent.  You have not named a single material that such a Fresnel lens could be plausibly made from.

Your analysis is also partly wrong because you keep conceptualizing the problem in a single way: a huge monolithic system.  That's why you come up with 2400km-sized arrangements and ridiculous forces, when a large number of 2.4m-sized objects would do.  In fact, anything one would use for that purpose, Fresnel lens or mirrors, would consist of a large number of small, individually navigable units; there is no reason to build a single monolithic system.

And you keep missing the fact that there are lots of other engineering possibilities for keeping the mirrors in place.


[ Parent ]

At least one of us is (none / 0) (#372)
by masher on Fri May 06, 2005 at 12:14:57 PM EST

The only suggestion I made was that mirrors are a better choice than Fresnel lenses...

A suggestion thoroughly disproven by both myself and the academic community.

Seriously, show some backbone and admit your mistake. If mirrors are such a wonderful idea, why has no one proposed them before? Benford wasn't the first one to propose a fresnel lens, and I know of two dozen plus papers suggesting everything from dust, metallic meshes, and occultive masses. But not mirrors.

Do you seriously believe you're so much wiser than the rest of the world? If so, please prove it to us...by making a suggestion that *works*. Everything so far has been scientifically unsound on a dozen different levels.

[a mirror] is the only surface that we can manufacture with sufficient area with technology available in the near future...

Here is your basic misunderstanding. A Fresnel lens is a sheet of corrugated plastic. A diffusive fresnel doesn't even need the global characteristics of a focusing lens.

you keep conceptualizing the problem [as] a huge monolithic system...when a large number of 2.4m-sized objects would do...

Haha, yes you're correct. Instead of one such Newtonian telescope, we could build 785.4 BILLION of them. That's how many you would need, scaled down to that size. Each of those with their own sophisticated system of thrusters and sensors to remain pointed exactly at the sun, and to avoid them colliding with each other or even coming close enough to occult each other.

Building smaller isn't always better. We can build one Sears Tower far easier than we can build one trillion fully-functional scale models of it, each with functioning doors, elevators, plumbing, etc.

Worse is the fact that the mass-to-effective area ratio explodes as scale goes down. So the total mass of this cloud of telescopes is far higher, raising the cost by a few orders of magnitude.

You have not named a single material that such a Fresnel lens could be plausibly made from....

A modified polyamide variant? Styrene-acrylonitrile? PMMA? Even simple cellulose acetate? I'm not a materials scientist...but there are a vast number of transparent polymers with high UV resistance and enough tensile strength.

You keep missing the fact that there are lots of other engineering possibilities for keeping the mirrors in place...

You keep failing to suggest any that work.

[ Parent ]
prior proposals (none / 0) (#373)
by jcarnelian on Sat Jun 04, 2005 at 04:36:44 AM EST

Seriously, show some backbone and admit your mistake. If mirrors are such a wonderful idea, why has no one proposed them before? Dyson, Freeman, (1989) "Terraforming Venus", Correspondence in JBIS, 42, 593. You keep failing to suggest any that work. No, you just keep failing to comprehend them.

[ Parent ]
The math (correction) (none / 0) (#361)
by masher on Fri Apr 29, 2005 at 01:56:44 PM EST

Just noticed a typo in the final result. The actual equation should be:

(rsail)3 = 1 - 1.6/(dareal)

[ Parent ]
Supervillainy: Astroengineering Global Warming | 371 comments (347 topical, 24 editorial, 0 hidden)
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