My physics is at the half forgotten undergraduate level. Nevertheless I can usually spot the flaw in a 2nd law breaker fairly quickly. Look at this suggestion from two years ago, and my rebuttal
Fu's device looks similar at first glance. Instead of a light-mumble-diode shining onto a light-mumble-diode to generate electricty, he has a thermionic emitter spraying electrons onto a thermionic reciever. So what? All he has done is to open a path so that the hotter can share its energy with the cooler.
Then he introduces the magnet. This matters because he is using charged particles instead of photons. Now if I want to run things backwards I have to reverse the polarity of the magnet. I cannot repeat my previous rebuttal. Naturally I want this to go to the front page. Then someone will post an explanation of why Fu's device will not actually work.
Is this kind of thing all that interesting? Yes! I read about the pawl and ratchet perpetual motion machine about 20 years ago. Later I was reading about DNA. You can think of the enzyme that copies DNA as a kind of machine that works its way along a single strand making the complimentary strand. But it is a very strange kind of machine, working at the atomic level. How does it know which way to go without some-one turning its handle?
Apparently it doesn't know which way to go. It chugs back and forth, making a bit of complimentary strand, and then unravelling it. If there is a strong concentration of Nucleic acids it the intra-cellular fluid average progress is forwards. If there is a weak concentration of nucleic acid, average progress is backwards.
When I read this I was very glad that I had already read about the pawl and ratchet machine. The notion that molecular level machines run both ways and need their direction set by a temperature gradient or a concentration gradient was already familiar, and I was able to understand the new stuff I was reading.
You'll notice the authors have no discussion of any potential systematic errors, there are no
error bars, despite the fact that the measured currents are close to the minimum sensitivity of
Fu's paper is half theory, half experiment. However he is not claiming any new physics. He is claiming a theoretical result, that he can use a magnet as a Maxwell's Demon. That is an extra-ordinary claim. It is natural to expect him to try it out.
There is much to worry about in his experiment set up. For example, with the magnets turned off, he zeros his electrometer. He simply assumes that no current is flowing. But if a current was flowing, then there would be a Hall effect when he turned on his magnet. Perhaps that is what he is seeing?
However, Fu is not claiming to have discovered new physics. He is proposing a novel arrangement of existing, well understood, elements. So the experimental part of his paper is a bit of a red-herring, the meat is in the theory. If the theory is sound researchers will soon get the experiment to work. If the theory is unsound Fu will discard his results as an artifact of a difficult to perform experiment; he is only trying to demonstrate the implications of his theory.
Ofcourse the theory is not sound. I would greatly apprecipate somebody telling me what is actually wrong with it. This is a theoretical issue and would still arise even if Fu had not reported any experimental results
[ Parent ]