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High-resolution mapping of the universe: WMAP First results - implications for cosmology

By olethros in Science
Wed Feb 12, 2003 at 02:13:21 PM EST
Tags: Science (all tags)
Science

The WMAP (Wilkinson Microwave Anisotropy Probe) project has made the headlines. Now we have a more detailed view of the background radiation than ever before. So what, the casual reader may ask. In fact, the new WMAP data can be useful for determining the correctness of current cosmological theories.

Articles for general public consumption have been published in New Scientist, the BBC and the the Washington Post. A similar article has been published in Science.

This article attempts to go slightly beyond what is mentioned in the short news announcements, however for a complete view of the group's work one should look at the articles they submitted for peer review.


The Big Bang theory assumes that the current state of the universe must have arisen from an earlier state of extremely high temperature and of an extremely small volume which rapidly expanded and cooled down in an explosion-like manner, which is why it is called the Big Bang theory. This explosion would have left a characteristic background radiation (CMB), that should be present in all of the universe, since all of the universe was part of the process. This was first verified by the COBE project in 1992, which did a similar map of the universe, but in a much lower resolution

WMAP did a high-resolution scan at the same frequency range, in five frequency bands from 23 to 94 Ghz. The new data is more precise, but remains consistent with the COBE data. The group has submitted a peer-reviewed paper analysing the basic results. This paper outlines all the basic methods followed.

An important point of the paper is that the calculated power spectrum is a complete representation of the data only if the Cosmic Microwave Background radiation (CMB) anisotropy is Gaussian1. Anisotropy here means that the CMB does not have a constant value over the whole sky , but it varies. The fact is that there is no guaranteed test that would assure us that the distribution of values is Gaussian. However the authors report results that indicate with high certainty that the distribution is indeed Gaussian.. One critical assumption is that all the observed fluctuations are because of (Gaussian) fluctuations in the gravitational potential.

One interesting thing to note is that the results indicate both a polarization and a large variability in the cosmic map. This comes at odds with the generally held assumption by Hubble that the universe is isotropic and homogeneous. This assumption has to be true in order for his law (that states that a star's distance from any other star is proportional to its relative speed) to hold in all cases. However if the universe is completely homogeneous then where did all the clumps of matter come from in the first place. The WMAP data (as well as the COBE data before) shows that the universe was not completely homogeneous even at the first moment of its existence. In general physicists regard the anisotropy as large enough to allow matter to form clusters in a very long time, but not so large as to be of significant effect with Hubble's law.

In fact Hubble's law did not seem to hold, as some very distant objects seem to be moving much slower than they should have. It seemed that only a repelling force that operated over long distances could explain this data, so dark energy was introduced. This repelling force actually accellerates the universe's expansion rather. Previously it was assumed that at large distances only gravity would be doing any work and thus, even though the universe would be expanding gravity would reduce its expansion rate or even stop expansion completely, possibly even causing the collapse of the universe into a Big Crunch. If the group's interpretation of the data is correct and assuming that of all the known forces only gravity would have an effect at large distances, the universe is expanding at an ever increasing rate, fuelled by the force provided by dark energy.2

Dark matter was another thing, introduced for a different but similar reason. It seemed that some galactic formations did not have enough mass to be held together. They would have needed to have a great amount of extra mass in order for their component galaxies to remain locked into a cluster. This matter's nature was deemed unknown and was called dark matter. This matter is also necessary in order to make the universe 'flat', so that parallel light beams will never intersect. The group also managed to use its data to characterise the type of this matter, if it exists, limiting it to low-temperature ranges (only Cold Dark Matter is possible)

The group claims that their data has a cosmological interpretation that supports the existence of both dark energy and dark matter in extremely high quantities, according to their calculations. The model that best fits the data assumes a flat universe with a baryon function of 0.044, a matter fraction of 0.27 and a 0.73 fraction of dark energy.

Another important outcome of this research was the determenation of a more exact number of the age of the universe, estimated to 13.7 +/- 0.2 billion years. The previous estimate was between 12 and 15 billion years.

Finally, the group has published a companion paper describing the data's implications to inflation theory. Inflation theory aims to explain the apparently faster expansion of the universe at its earliest stages of development. This is also related to the fact that their data shows the existence of stars at an extremely early age of the universe. It seems that stars started to form much earlier than cosmologists had previously thought.

The above results are mostly verifications and refinements of currently more or less accepted cosmological theories and observation. These results are expected to be much more refined in the future as the group will be able to calibrate the instrument with larger precision and also be ableo filter out more noise, simply because of increased observation time.

One of the most surprising results however, concerns what the data shows hapenned shortly after the big bang. At the initial stages of atom formation the universe was still quite hot and there were no atoms yet, just nuclei and electrons, otherwise viewed as hydrogen in an ionized state. After the universe cooled down and the electrons and protons combined into atoms this ionization should have disappeared. However the group has ascertained that ionization reappeared after the cooling down event, possibly because of massive photonic emissions.

Conclusion

The study is extremely interesting and its implications profound. You are urged to read the introductory paper and the cosmological parameter paper. The latter is quite long but it explains things clearly enough. The group does make a number of assumptions, which could be of critical importance, but their work is clearly defined and when viewed within the scope of the assumptions it seems infallible. Compared to studies where conclusions are drawn only from observations of a few stars whose age and distance can only be approximately known, such a study is much more rigorous and has to be taken seriously.

Notes

1: A Gaussian is a smooth function with a single peak. In this context we are using a gaussian to describe a random process. A gaussian random process is described by a gaussian distribution (another name for the curve). The process in this case is the observed intensity of background radiation. A gaussian has interesting properties as a distribution, such as the fact that adding together events that are described by infinitely many non-gaussian distributions results in an overall gaussian distribution. This page talks in a lot more detail about what the guassian is and why it so special. It also discusses the tests made to see if your data obeys a gaussian distribution or not and thus would be useful towards an understanding of the gaussian conformity paper published by the group.

2: I am also unsure whether the dark energy referred to in this work relates to quintessence or the the energy spoken of in Parker, L. & Raval, A. A new look at the accelerating universe. Physical Review Letters 86, 749 - 752 (2001)., which is an alternative model for an accelerating universe.

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Poll
Dark Matter/Energy.
o There is insufficient evidence. 29%
o Under the assumptions used, the evidence is sufficient 33%
o It is meaningless in standard models of the universe. 3%
o Dark energy and dark matter are different manifestations of the same thing. 22%
o There is something else that explains the data better. (Please comment) 11%

Votes: 27
Results | Other Polls

Related Links
o WMAP
o New Scientist
o BBC
o the Washington Post
o Science
o basic results.
o distributi on is indeed Gaussian.
o cosmologic al interpretation
o calculatio ns
o implications to inflation theory
o cosmologic al
o This page
o Also by olethros


Display: Sort:
High-resolution mapping of the universe: WMAP First results - implications for cosmology | 78 comments (51 topical, 27 editorial, 0 hidden)
Dark Matter RPG (2.50 / 4) (#24)
by guyjin on Wed Feb 12, 2003 at 12:38:13 PM EST

Anyone remember the 'Dark matter' setting for the Alternity game? that thing roxored!
-- 散弾銃でおうがいして ください
I am going to plot your donkey (1.73 / 15) (#27)
by medham on Wed Feb 12, 2003 at 01:05:44 PM EST

Several items of note:

  1. These findings confirm deconstruction's critique of teleological Western metaphysics.
  2. These findings came from NASA, controlled entirely by the capitalist military-industrial complex, and thus I must wait until we have socialist confirmation before I can accept the results.
  3. "Dark energy" is the same thing as the dialectic. So is "dark matter." You'd have to refute Marx to claim otherwise (remember his dissertation!)
  4. Caribune queen--now we're living the same dream, and our hearts can beat as one (no more love on the run).
  5. Caro Giorgio--Ti abbracio.
  6. How can we stop the expansion?

The real 'medham' has userid 6831.

sad (5.00 / 2) (#46)
by demi on Wed Feb 12, 2003 at 08:13:38 PM EST

Already hating yourself at such a young age.

[ Parent ]
Socialist research? (none / 0) (#47)
by exceed on Wed Feb 12, 2003 at 08:46:30 PM EST

These findings came from NASA, controlled entirely by the capitalist military-industrial complex, and thus I must wait until we have socialist confirmation before I can accept the results.

I bet you there were some European scientists working on this one with NASA, too...

void women (float money, time_t time);
[ Parent ]
0'ed by boxed (2.50 / 2) (#56)
by veldmon on Thu Feb 13, 2003 at 07:32:51 AM EST

Rainbow UKian strikes again.

[ Parent ]
Flat? Bummer. (none / 0) (#29)
by pla on Wed Feb 12, 2003 at 04:23:24 PM EST

I had *so* hoped for hyperbolic, perhaps even high-order toroidal. But nope, just plain ol' boring nothing-special flat. Though at least we didn't get parabolic or low-n-spherical, that would kinda suck.

Yay. Looks like Euclid *did* get it right.


Of course, OTOH, a flat universe means an "out there" exists for the universe to expand into (as opposed to wrapping back into itself). I suppose that has some potential, except for the whole speed-of-light thing.


So, dark matter and dark energy.

Perhaps one of K5's physics geeks can explain something to me... Aside from the "obvious" inferential evidence (ie, the expansion rate of the universe), how do we distinguish between dark matter and dark energy? Or even between baryonic matter really far away and too dim to see, and dark matter?


Don't be too bored (5.00 / 1) (#35)
by manobes on Wed Feb 12, 2003 at 05:56:45 PM EST

The 4D geometry of the universe is not flat, only 3D slices.

Perhaps one of K5's physics geeks can explain something to me... Aside from the "obvious" inferential evidence (ie, the expansion rate of the universe), how do we distinguish between dark matter and dark energy?

I'm not an expert on this, but the general idea is simple to understand. Dark matter has *local* effects. That is, it has effects on things like galatic dynamics. So if you go out and try to measure the rotation profiles of galaxies you'd find evidence for dark matter, but not for dark energy.

By adding up all the dark matter we can "see" in galaxies you can get a total, which is then added to the total amount of baryon matter. The rest is dark energy, which must operate on a larger scale.

Or even between baryonic matter really far away and too dim to see, and dark matter?

This is probably a matter of averageing. You assume that a "typical" galaxy very far away is similar to one closer to us. Then you subtract the typical amount of baryonic matter for that type of galaxy to get the amount of dark matter.


No one can defend creationism against the overwhelming scientific evidence of creationism. -- Big Sexxy Joe


[ Parent ]
Age of universe (3.00 / 2) (#30)
by nusuth on Wed Feb 12, 2003 at 04:58:14 PM EST

The claim seems to be much more accurate compared to the earlier ones. Can anyone fill me how they arrived at such a certain figure?

It is all explained (none / 0) (#42)
by olethros on Wed Feb 12, 2003 at 07:41:06 PM EST

in the introductory paper and the cosmological constants paper. I have provided links. They actually have quite a clear introduction and conclusion and you can skip the middle, which has all the math.

Of course if you want to know HOW they measured it you have to look at the math. You also have to look at the instrument calibration papers and the papers on how to remove foregrand radiation noise. Anyway, go back and read the introductory paper. It does not have a lot of math, but unfortunately contains a lot of physics buzzwords. From the introductory paper you can get pointers to companion papers of interest to you.
-- Homepage| Music
I miss my rubber keyboard.
[ Parent ]

Dark Matter / Dark Energy (none / 0) (#31)
by PullNoPunches on Wed Feb 12, 2003 at 05:03:47 PM EST

So, we have hypothesized something we call "Dark Energy" to account for an otherwise unexplained repulsive force, and "Dark Matter" to account for an otherwise unexplained attractive force.

I'm a little suspicious of the existence two purely hypothetical entities, with no direct evidence for them, and with exactly opposite properties. (and if the universe is indeed flat, then also found in precisely balanced proportion?). Seems like it's time to whip out the old Razor of Occam and try a little slice and dice on that multiplicity of entities.

------------------------

Although generally safe, turmeric in large doses may cause gastrointestinal problems or even ulcers. -- Reader's Digest (UK)

Hmm (4.00 / 1) (#33)
by manobes on Wed Feb 12, 2003 at 05:49:23 PM EST

I'm a little suspicious of the existence two purely hypothetical entities, with no direct evidence for them,

Umm, there is direct evidence for them. At least as direct as we're likely to get. Namely the data that this experiment (and others) are reporting. What more do you want?

That is, dark energy theories (i.e. general relativity with a cosmological constant) predict that the galaxies will be accelerating away from each other, we go out and measure that they are, ergo, we likely have some form of dark energy...

As for dark matter, there's plenty of evidence for that from things like rotation curves of galaxies.


No one can defend creationism against the overwhelming scientific evidence of creationism. -- Big Sexxy Joe


[ Parent ]
Re: Hmmm (none / 0) (#36)
by PullNoPunches on Wed Feb 12, 2003 at 06:13:19 PM EST

Unless I'm missing something, the evidence isn't direct, it is that there must be something causing the observed effects. Fair enough, I'm not disputing that there is something there. My point is that the hypothesis says there are two somethings. I'm just wondering if there is a chance that there is a simpler explanation that doesn't multiply somethings so readily.

------------------------

Although generally safe, turmeric in large doses may cause gastrointestinal problems or even ulcers. -- Reader's Digest (UK)
[ Parent ]

See my other post (none / 0) (#37)
by manobes on Wed Feb 12, 2003 at 06:33:53 PM EST

Fair enough, I'm not disputing that there is something there. My point is that the hypothesis says there are two somethings. I'm just wondering if there is a chance that there is a simpler explanation that doesn't multiply somethings so readily.

My other comment (further down) talks about why we think it's two different things. The short answer is that the dark matter has a *local* effect, on things like galatic dynamics, whereas the dark energy only has a large scale effect.


No one can defend creationism against the overwhelming scientific evidence of creationism. -- Big Sexxy Joe


[ Parent ]
A small view on dark energy (none / 0) (#40)
by olethros on Wed Feb 12, 2003 at 07:32:38 PM EST

I did not want to put this in the main article as it would represent my views purely and reflect on my poor understanding of the subject. :)

Anyway, they just used two things because dark matter seems to have an effect on smaller scales (galactic scale), while dark energy describes an effect on larger scales (inter-galactic).

My little pet theory about this is that dark energy may very well exist, but dark matter need not be there. Why? Well, if there is a weak, but non-vanishing force that permeats space and which has a repelling effect between masses, it could be this force that actually holds the problematic galactic clusters together. This could be similar to how bubbles are possible in fluids. Although the gas should escape and be dissolved homogenously, the water pressure itself holds the bubble in place. So what happens is that the repelling force from the far-away galaxies that surround the cluster is more or less isortropic, i.e. it is the same in every direction and actually pushes the elements of the cluster together.

Just an idea, anyway.
-- Homepage| Music
I miss my rubber keyboard.
[ Parent ]

At least you got my point (none / 0) (#58)
by PullNoPunches on Thu Feb 13, 2003 at 01:57:31 PM EST

I can't say whether your idea has any holes in it (I can think of a few possible, but I won't get into them here), but at least you caught on to what I was getting at.

------------------------

Although generally safe, turmeric in large doses may cause gastrointestinal problems or even ulcers. -- Reader's Digest (UK)
[ Parent ]

heh (none / 0) (#49)
by Work on Thu Feb 13, 2003 at 01:17:01 AM EST

dark energy and dark matter are two totally different concepts, with little in common. Dark Matter is not 'the opposite' of dark energy. Dark Matter is a catch-all term for gravity generating 'something' that we havent detected yet.

[ Parent ]
Hm (5.00 / 1) (#53)
by olethros on Thu Feb 13, 2003 at 04:06:27 AM EST

I think you meant to say
"Dark Matter is matter that we have not seen but which we assume that it is there because of an apparent gravitational effect."

And
"Dark Energy is an energy of unknown source which we assume must exist because an apparent accelerating effect on the universe's expansion"
-- Homepage| Music
I miss my rubber keyboard.
[ Parent ]

right (none / 0) (#57)
by Work on Thu Feb 13, 2003 at 11:33:13 AM EST

but as the other guy said, the gravitational effect caused by the dark matter is more localized than the dark energy.

[ Parent ]
Important note (5.00 / 1) (#32)
by Joh3n on Wed Feb 12, 2003 at 05:04:13 PM EST

While WMAP does show fluctuations away from homogeneity, the assumption that the universe was homogeneuos and isotropic (A FLRW metric) still works fantastically well for earlier times.  Case in point, nucleosynthesis (at times around a few minutes after the bang, verses a few hundred thousand years when last scattering occured).  

During nucleosynthesis, inhomegeneities would leave a rather noticeable imprint on things like the light element abundances which we do not observe.  Granted, some fluctuations existed at these times too (presumably set down even before inflation), but they are certainly sub-dominant.

Fortunately for me (I'm one of the people who finds the baryon density by other means than the CMB), WMAP's determination of the baryon density and ours are happily concordant.

WMAP's success as a relatively cheap mission is certainly admirable (although, I think they're pushing it with z-1089 +/- 1 ).
---------------------------------
You can learn a lot about someone by popping in their un-rewound pr0n tape and seeing where exactly they came.
-terpy

I don't see how the initial (none / 0) (#34)
by Skywise on Wed Feb 12, 2003 at 05:50:40 PM EST

start point could NOT be isotropic.  (or at least nearly isotropic.)  Unless there was more than just hydrogren at start time.

(Unless maybe the Dark Matter that was the shell casing around the source material got turned into shrapnel?  :) )

[ Parent ]

Well (none / 0) (#45)
by Joh3n on Wed Feb 12, 2003 at 08:10:00 PM EST

At 'initial' times, there was no hydrogen, it was far too hot.  Only at the beginning of nucleosynthesis did things cool down enough for protons and neutrons to be able to bind.

The CMB itself comes from the time when the universe cooled to the point where electrons could be bound to atoms.
---------------------------------
You can learn a lot about someone by popping in their un-rewound pr0n tape and seeing where exactly they came.
-terpy
[ Parent ]

Anti-matter (5.00 / 1) (#38)
by Verteiron on Wed Feb 12, 2003 at 07:09:25 PM EST

Can someone who's more knowledgable about cosmology explain to me why we are made of matter, instead of antimatter? Was there just a teensy bit more "regular" matter at the BB than there was antimatter? If so.. why?
--
Prisoners! Seize each other!
Somewhat complicated (5.00 / 1) (#39)
by manobes on Wed Feb 12, 2003 at 07:13:15 PM EST

Can someone who's more knowledgable about cosmology explain to me why we are made of matter, instead of antimatter? Was there just a teensy bit more "regular" matter at the BB than there was antimatter?

The accepted answer seems to be that at the BB there was matter anti-matter symmetry. However the standard model of particle physics has a phenomena known as CP violation. Basically the laws of nature are *not* symmetric when you flip all you're coordinates (x -> -x) and charges. This means that there is a distinction between matter and anti-matter and, through a process first thought up by Shakarkov a matter-antimatter asymmetry can be built up starting from perfect equality. This is our best idea as to how the universe came to be matter dominated AFAIK.


No one can defend creationism against the overwhelming scientific evidence of creationism. -- Big Sexxy Joe


[ Parent ]
A more heretical idea (none / 0) (#41)
by olethros on Wed Feb 12, 2003 at 07:36:17 PM EST

concerns the interpretation of Feynman's QED formulas the describe anti-matter as matter that moves backwards in time literally. This means that at the big bang anti-matter moved one path down time and matter in the opposite direction so there only was as much matter anti-matter at the beginning of time and not at any time afterwards.

This idea is not to be taken seriously unless you take the formulas quite literally. I have certainly not seen anyone pushing it as a reasonable explanation.

-- Homepage| Music
I miss my rubber keyboard.
[ Parent ]

If we were made of antimatter... (4.00 / 1) (#44)
by fluffy grue on Wed Feb 12, 2003 at 07:56:16 PM EST

then it'd be called matter and what we're currently made of would be called antimatter.

Similarly, if the sundial were invented in the southern hemisphere, what we call "clockwise" would be counter-clockwise. And then screws would be screwed in a direction might be more suited for right-handed peoples' wrists.
--
"Is not orange" is not orange.
"Is not a quine" is not a quine.

Cats: Nature's entropy generators

[ Hug Your Trikuare
[
Parent ]

screws (none / 0) (#60)
by labradore on Fri Feb 14, 2003 at 12:31:27 AM EST

I think that you are saying that clockwise-in screws are less optimal than counter-clockwise-in screws. Why would you say this? My best guess is that most people can develop greater power when using their right hand to turn a screwdriver clockwise verses counter-clockwise. Also, when a person holds and twists a screw-driver in the typical thumb-down, fingers-curled-clockwise manner with his right hand, he can develop a stronger grip on a round-ish screwdriver than when turning it counter-clockwise, since the finger muscles that squeeze are assisted by the forearm muscles that twist in clockwise motion.

[ Parent ]
Yeah, probably (none / 0) (#62)
by fluffy grue on Fri Feb 14, 2003 at 01:21:09 AM EST

I didn't really think about the mechanics of it, but you're right, the current standard screw direction probably evolved separately from the notion of clockwise.
--
"Is not orange" is not orange.
"Is not a quine" is not a quine.

Cats: Nature's entropy generators

[ Hug Your Trikuare
[
Parent ]

Because anti-matter is wussy. :) (none / 0) (#65)
by Verax on Fri Feb 14, 2003 at 06:55:59 AM EST

Can someone who's more knowledgable about cosmology explain to me why we are made of matter, instead of antimatter? Was there just a teensy bit more "regular" matter at the BB than there was antimatter? If so.. why?

I'm not all that knowledgeable, but I talk to some people at SLAC who are. What it boils down to is that matter and anti-matter particles come into existence in equal pairs, always. At SLAC, they have a huge detector called BaBar, and have been gathering a massive amount of data (world's biggest database) on particle events. The bottom line is that antimatter decays more quickly than matter does. Here's a link . I'm sorry it's not as informative as what I had been hearing. I recall that after having analyzed all the data, they say there's only about a 6 parts in 100,000 chance that their conclusion (faster anti-matter decay) is wrong.



----------------------------------------------
"It is a poverty to decide that a child must die so that you may live as you wish." -- Mother Teresa of Calcutta
[ Parent ]
Newtons third law (1.50 / 2) (#48)
by dollyknot on Wed Feb 12, 2003 at 08:52:27 PM EST

Newtons third law : Every action has an equal and opposite reaction, this assumes that the universe is cartesion. Reason being, if the line is opposite and straight it will continue for infinity. If the universe is not cartesion, then the equal and opposite reaction is in fact a curve, meaning it will eventualy curve back on itself and no longer be opposite.

Einstein proved Newton wrong on time, how do we know Newton was right in terms of space re gravity and his third law. The voyager probe did not behave as expected.

I suspect it is in the area of Fermat's last theorem. Pythagorus = 3^2+4^2=5^2. This deals with two dimensions. If you can make the same ratio balance with cube roots, you are dealing with the three dimensions, no wonder it has been driving mathematicians nuts, for a long time. Yeah okay, they reckon they solved it, but in no way would it fit in a margin.
They call it an elephant's trunk, whereas it is in fact an elephant's nose - a nose by any other name would smell as sweetly.

what? (4.00 / 1) (#50)
by Work on Thu Feb 13, 2003 at 01:24:21 AM EST

fermat's theorem was proven correct - that is, there is *no* non-trivial solution to x^n+y^n=z^n, where n > 2. There isn't a 'balance' like the pythagorean theorem has.

Just because the proof is long and complicated doesn't mean its invalid because it wont 'fit in a margin'. How ridiculous.

You seem to misinterpret newton's third law as well. The expanding universe has no opposite reaction, because there isn't anything outside of it to press back at it. The laws of the universe do not operate outside of the universe. Perhaps you would be confused too by the inflationary period of the early universe, where it expanded faster than the speed of light, because it was space itself expanding, which doesn't have to follow the laws of physics.

[ Parent ]

Everything Work said, and also . . . (none / 0) (#52)
by ZorbaTHut on Thu Feb 13, 2003 at 01:54:35 AM EST

. . . the three-dimensional equivalent to the Pythagorean theorem isn't x^3 + y^3 = n^3, it's x^2 + y^2 + z^2 = n^2.

Not only *that*, but there's no reason to restrict science to integers - there are plenty of solutions to x^3 + y^3 = n^3 that aren't integral :P

[ Parent ]

You nerds discust me. (1.33 / 6) (#51)
by veldmon on Thu Feb 13, 2003 at 01:30:13 AM EST

But I do enjoy Star Trek.

0'ed by boxed (2.75 / 4) (#54)
by veldmon on Thu Feb 13, 2003 at 05:45:33 AM EST

Rainbow UKian strikes again.

[ Parent ]
1'ed by twistedfirestarter (3.33 / 3) (#55)
by veldmon on Thu Feb 13, 2003 at 07:20:39 AM EST

Thank you for the opportunity to express my outrage at having a reasonable comment 0'ed by the user boxed.

[ Parent ]
Reasonable? (none / 0) (#59)
by carbon on Thu Feb 13, 2003 at 10:28:16 PM EST

Reasonable comments usually say something at least halfway relevant about the topic. Aie, IHBT.


Wasn't Dr. Claus the bad guy on Inspector Gadget? - dirvish
[ Parent ]
0'ed by ragabr (5.00 / 1) (#70)
by veldmon on Sat Feb 15, 2003 at 11:23:47 AM EST

Rainbow GNUian strikes again.

[ Parent ]
0'ed by ragabr (5.00 / 1) (#71)
by veldmon on Sat Feb 15, 2003 at 11:24:38 AM EST

Rainbow GNUian strikes again.

[ Parent ]
Help me! (3.00 / 1) (#61)
by vbpdjoe on Fri Feb 14, 2003 at 12:51:58 AM EST

I admit I'm not well informed on this topic, but...

When I hear things like:
The study is extremely interesting and its implications profound--we just found out that after the big bang 13.7 billion years ago there were no atoms yet, just nuclei and electrons.

My gut reaction is: Bull Shit.

Can someone really think, with some level of confidence, that they know something about microscopic stuff that was around 13.7 billion years ago?

I admit I could be wrong...but, without jumping immediately into this study, where should I go to learn and be convinced?

Someone save me from my ignorance, please?

Well... (none / 0) (#63)
by manobes on Fri Feb 14, 2003 at 02:20:18 AM EST

Can someone really think, with some level of confidence, that they know something about microscopic stuff that was around 13.7 billion years ago?

Yes. So long as you accept the seemingly resonable assumption that the laws of physics were the same then as they are now. Given that, the current theories we have are adequate to describe things back until a few nanoseconds before the big bang. This data confirms this assumption by agreeing with predictions of various models which use these physical theories.

Furthermore, this study is just one of several which all point to the same conclusions, via very different observational techniques. The fact that many lines of observation tend to all point to the same model gives one great confidence.

I admit I could be wrong...but, without jumping immediately into this study, where should I go to learn and be convinced?

Modern cosmology is a huge field. It would be difficult to truely understand these results without, at the least, a strong undergraduate physics education. A very good book to read at a more popular level is The Big Bang, by Joeseph Silk. It's a bit dated, but it lays out a lot of the "classical" evidence in a very nice way.


No one can defend creationism against the overwhelming scientific evidence of creationism. -- Big Sexxy Joe


[ Parent ]
Thanks... (none / 0) (#67)
by vbpdjoe on Fri Feb 14, 2003 at 08:09:07 PM EST

For Nothing! :)

I found this, though, for those who want an intro without buying a book:
http://map.gsfc.nasa.gov/m_uni.html

[ Parent ]
Nothing? (none / 0) (#68)
by manobes on Sat Feb 15, 2003 at 02:04:14 AM EST

I answered your question didn't I?

And while that's a nice website you'd learn more from Silk's book.


No one can defend creationism against the overwhelming scientific evidence of creationism. -- Big Sexxy Joe


[ Parent ]
Congratulations (5.00 / 1) (#64)
by carbon on Fri Feb 14, 2003 at 05:44:46 AM EST

My gut reaction is: Bull Shit.

Congratulations; you are now a scientist.


Wasn't Dr. Claus the bad guy on Inspector Gadget? - dirvish
[ Parent ]
Another go (2.00 / 1) (#66)
by dollyknot on Fri Feb 14, 2003 at 12:12:40 PM EST

My comment about Fermat's last theorem, was an intuitive thing, not a statement of logical causality.

The main plank of my objections to the conclusions reached from the latest observations from WMAP are the same objections I have had for many years, regarding current cosmological theory.

Dark matter is purely a conjecture used to make empirical observation fit known (sic) cosmological theory.

'Till his dying day Einstein maintained he never understood gravity. I take this to mean he was able to unify strong nuclear, weak nuclear and electromagnetic forces in one theorem, problem was, he was unable to conceive of an equation that fitted gravity in as well. Since Newtons day, gravity has been seen to be, purely an attractive force between two atoms. Newton saw the universe as cartesian and clockwork. Einstein showed this view of the universe was erroneous, by being able to predict the orbit of Mercury whereas Newton's equations, could not predict the orbit of Mercury.

As I sit here typing this, my body hurtles in a circular direction eastwards, at thousands of miles an hour, whilst this circle happens, another circle occurs in a different direction, as what I am sitting on, spins around the sun. To further complicate matters, the sun itself appears to be orbiting something.

What do all these compounded motions mean in terms of gravity - nothing according to current cosmological theory, apart from the idea that atoms are attracted to each other, by a virtually invisible quantum force.

By some definitions the mobius strip has only one side, as to wether it only has one side, well in some ways, yes it only has one side. What if the mobius strip has only one side kinetically? Has anyone checked this out? Probably not, because anyone with half an education, already knows that gravity is only a function of atom attraction, so why bother?

How do we know the universe is not a four dimensional klein bottle with time as the forth dimension?

I state again, voyagers behaviour did not conform to theory predictions.

The paragraphs in this comment are copyleft

Happy hunting

Peter.
They call it an elephant's trunk, whereas it is in fact an elephant's nose - a nose by any other name would smell as sweetly.

Why gravitational (none / 0) (#69)
by olethros on Sat Feb 15, 2003 at 09:05:45 AM EST

Interestingly, the formation of stars and galaxies is usually attributed to gravity:

Most cosmologists believe that the galaxies that we observe today grew gravitationally out of small fluctuations in the density of the universe..

Such fluctuations can be measured from background radiation, but I still do not understand why only gravity would have an effect. Especially since the universe was much smaller when it was young, electromagnetic forces could have had a very significant effect.

In fact, I remember seeing a mention, 10-15 years ago perhaps, of an electromagnetic theory of galaxy formation that supported galactic structures that were otherwise not explained by models that only relied on gravity. I have no reference for it, however.
-- Homepage| Music
I miss my rubber keyboard.

Can I ask a silly question? (none / 0) (#72)
by f0rTyLeGz on Sat Feb 15, 2003 at 10:12:05 PM EST

Assuming that the Big Bang then Big Crunch theory is true, can we assume that after the Big Crunch comes another Big Bang?

If that's the case have their been an infinite number of these Bangs and Crunches?



Not silly (none / 0) (#73)
by MyrddinE on Sun Feb 16, 2003 at 04:59:50 PM EST

But not answerable either. The big bang/crunch essentially destroy all information (as far as we can guess), so no information remains about previous bangs and crunches. This could be the first, it could be the billionth... we cannot tell. Only by moving to a reference point outside our universe (ha!) will we be able to discover that.

[ Parent ]
I agree (none / 0) (#74)
by dollyknot on Sun Feb 16, 2003 at 06:05:18 PM EST

Reason being - the paradox of the uncaused causality. I hold to the doctrine that everything has a cause, I cannot concieve that the big bang just popped into existence, I have no evidence that it did not just *pop* into existence, I just believe that everything has a cause, therefore the big bang must have had a cause.

I made my views clear about gravity earlier on, just because the expansion rate of galaxies appears to be accelerating, does not to mean it actually is, or if it actually is, wether it will continue to do so. As Wittgenstein once famously put it 'What would it look like if the sun was going around the earth?'

Accepting the possibilty that the big bang was caused by a big crunch throws up some very interesting posibilities, Nietzsche wrote about this with his theory of eternal recursion. I seem to have a vauge idea that some of the ancient Greek thinkers thought this way too.

Given exactly the same seed and exactly the same environment, would you not end up with exactly the same organism? Something like, you always get the same stream of numbers from pi.

It gets better <grin> death, forget it, you have eternity. Like when your body is old tired and worn out and your consciousness finally gives up the ghost. You sleep for a trillion zillion billion years and you are born anew in your mum's womb, to go through the whole darn rigmarole again. Or have I written this before? heh will I have to write this for eternity? Another nice spin off from this theory is, you never have to worry about where the universe came from - it was always here. It also has a zen essence.
They call it an elephant's trunk, whereas it is in fact an elephant's nose - a nose by any other name would smell as sweetly.
[ Parent ]

Right! (none / 0) (#76)
by f0rTyLeGz on Mon Feb 17, 2003 at 01:27:19 AM EST

And another way, in an infinite number of B@C's, you will live this life and infinite number of times.

[ Parent ]
Well.. (none / 0) (#75)
by manobes on Sun Feb 16, 2003 at 06:16:59 PM EST

Assuming that the Big Bang then Big Crunch theory is true

The evidence reported in this article, along with a large amount of other evidence pretty much rules out the big crunch theory.

If that's the case have their been an infinite number of these Bangs and Crunches?

Well, that depends. If the crunch/bang cycle preserved entropy then the answer to that would be no. After a few crunchs, any non-randomness in the universe would get smoothed out to nothing, making an interesting universe (i.e. one with galaxies) impossible. But, like I said, the crunch theory as it stands right now, is ruled out.


No one can defend creationism against the overwhelming scientific evidence of creationism. -- Big Sexxy Joe


[ Parent ]
Flat Universe is Heavy (none / 0) (#77)
by rustyk on Sat Apr 05, 2003 at 05:49:50 PM EST

When Matter gets near the speed of light it flattens out and nears infinate mass. Could "dark matter" just be traveling faster than light? Our Universe is "3-D" because it is made of slower than light - non flattened - matter? Would this then create a seemingly flat looking universe at giantic scales?

Inertia (none / 0) (#78)
by olethros on Mon Apr 14, 2003 at 04:18:55 AM EST

High-speed travel only increases inertial mass, not the gravitational pull of a body. Read the standard example of two masses travelling towards each other at a speed close to light-speed, it explains stuff.
-- Homepage| Music
I miss my rubber keyboard.
[ Parent ]
High-resolution mapping of the universe: WMAP First results - implications for cosmology | 78 comments (51 topical, 27 editorial, 0 hidden)
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