exchemist

The point is that any heat pump requires an external energy input. It can be mechanical work, as provided by the motor in a domestic fridge, or it can be something else, say, electricity in the case of a Peltier device or something. But heat will not spontaneously flow against a temperature gradient. Energy input is required to make it do that. So if your device - regardless of what it is and how it is constructed - gets heat to flow against a temperature gradient to produce a hotter side and a colder side where there was none before, there has been an energy input somewhere. By the way, the reason you get attacked, by me and others, is blatantly obvious to anyone with a smidgeon of intelligence. You are obsessed with trying to overturn one of the best-established and best-validated principles in science and - in particular - dodging all the patient explanations that have been made as to why you can't do that. So stop playing the victim, when it is you that has chosen to wander about with a huge "KICK ME' sign strapped to your arse.

Ah yes, I can see the telecoms information would be harder to get by other means. It will be interesting to see what the authorities disclose about their findings from the debris.

Is there a source for that hypothesis , or is it a personal speculation? I suppose it is possible it was indeed a stunt, or test, to sow confusion and watch reactions, but that does not seem to account for China having a whole fleet of them, sent to all corners of the world.

@toucanamentioned that. We know it seems important to them. We don’t know why, though. What does it do that satellites don’t, for instance?

You understand me well! Indeed, as a chemist what interests me is what happens at the level of molecules, or the electron orbitals in a giant structure such as glass. Also the link with spectroscopic properties, which I found so eye-opening. From the discussion so far I would hazard a guess that what we have may be a bit similar to what happens in bonding, when the spherical potential of an isolated atom is replaced by, say, the tetrahedral potential of something like methane. You can then get mixing of the atomic orbitals of the spherical case to form new combinations, appropriate to the new symmetry - the so-called orbital hybridisation: s + 3x p -> 4 x sp₃ in the methane case. With light passing through a medium, the electric field is antisymmetric, so the temporary induced polarisation could maybe be expressed as a transitory mixing of (spherical) states of different symmetry. This looks very much like the "transition dipole moment" involved in an absorption event.

No we accept the c.19th laws of thermodynamics based on 150 years of subsequent theoretical support for them and 150 years of subsequent experience. But if you want to claim Newton's Laws of Motion should be thrown out, just because they date from the c.17th and are thus a bit old, be my guest.😁

Indeed, I am not saying that. As I said in earlier posts, Lincoln's portrayal of it is that there are two component waves, that due to the light itself and that due to the secondary forced oscillation of the medium's electrons, and what actually takes place is the resultant, from the superposition of the two components. This is unavoidable as the two components will willy-nilly interfere to produce a single combined waveform.

Making clear that Xi may not have been aware of the flight also lays the ground for a later rapprochement, by offering him a ladder to climb down. He can fire a few military people and get back to the agenda. (I too was struck by the similarity to the Gary Powers affair.)

How remarkably uninformative. Are you a 'bot?

No, I'm sure Lincoln is not referring to an electron wave function. He is speaking in terms of a semi-classical model, in which the collective forced oscillation of the electrons in the medium sets up a secondary electric field wave, moving with the electric vector of the light but more slowly, and the superposition of the two leads to a reduction in phase velocity. The important part of the video comes in the final 3 minutes. The rest is background explanation of what refractive index is, why some of the popular explanations are wrong, and so forth. By the way, I'd like very much to hear your simpler explanation, if you care to summarise it. I find this an interesting topic and I feel I'm on slightly shaky ground relying just on what I recall from Peter Atkins at Oxford in 1974! But maybe I can get the gist of it from your posts up to this point. I'll read them carefully. I like this a lot. It contains the idea that energy is borrowed from the light by the lattice electrons, which quantum mechanically can - I think - be thought of as mixing in a bit of, mainly, the nearest excited state (in transition frequency). This is the exciting piece, to me, as it explains the link between the magnitude of refractive index and the proximity in frequency of absorption bands in the spectrum of the medium.

I think Lincoln is saying the motion of the electrons creates a secondary oscillating electric field (a forced oscillation, actually), moving slower than that of the incoming light and that the resultant speed of light in the medium arises from the superposition of the two electric field waves. I am unable to say for sure whether this classical-sounding explanation is the equivalent of the QM explanation that I think I recall. But it sounds as if it may be. This is actually quite an interesting and tricky subject.

Yes, London forces result from mutual polarisability of the molecules involved.

Yes, the permittivity being the classical electromagnetic term, equivalent to the polarisability at the molecular level, that is to say the degree to which its electron orbitals distort in response to the oscillating electric field of the radiation.

Yeah but my understanding is absorption is merely the limiting case of refractive index, not a totally separate phenomenon. That's why the refractive index goes up as you approach the absorption line. We may not actually be disagreeing, in that your new externally induced potential can lead to a new ground state that is the equivalent of a mixture of the ground and excited states in the undistorted (spherical potential) case.

It's years since I studied this, but my recollection is that the distortion (polarisation) of the electron distribution mixes in some proportion of a higher energy state. Recall that there is a "transition dipole moment" involved in the absorption process that occurs when the frequency is exactly right, involving both states, that is made possible by the perturbation due to the electric vector of the radiation.

The question in the post to which you were responding, of course. This was (just to remind you): "What about the picture that show the experiment at a later state? " The diagrams and stuff you posted instead of answering it were irrelevant, because they were trying (as usual) to change the subject, instead of answering the question that had been asked. Every time we get close to evidence that does not fit your preconceptions, you duck the issue and hastily veer off, with a smokescreen of more fiddly details of your experimental setup. I do not believe you are responding in good faith.

Ah thanks, now I understand. I was not familiar with the abbreviations.

The electrons of the material can oscillate at certain resonant frequencies that cause them to move between different energy states. This is how absorption and emission of light take place. If the frequency of the radiation is close to one of these frequencies but does not match, it can only cause the electrons to move temporarily to the higher state and then return. (If the frequency matches exactly, the electron can absorb a photon and move permanently to the higher energy state.) N.B. The light is not absorbed and re-emitted, as it is something said to be in bad explanations. It is just that the electron "borrows" energy from the wave it and gives it back. The effect is a bit like if you try to run on a trampoline: it absorbs and then releases energy from the wave. This slows down the phase velocity of the light. The closer to the absorption frequency the light is, the more it gets slowed down. In the limiting case, when the frequency matches exactly, it is absorbed, i.e. it is stopped! This is why glass is a dispersive medium, i.e. the refractive index depends on the frequency. The absorption frequency is in the UV, so as light frequency goes from red to blue, it is getting closer to the absorption frequency and thus the refractive index for blue light is greater than for red light. But refractive index is quite a complex phenomenon and really needs QM to explain it properly. It is related to polarisability - the ease with which a material can be polarised by an electric field. P.S. I actually watched most of your linked YouTube video, something I rarely do. I thought his explanation was good, avoiding the usual pitfalls of non-mathematical analogies.

Sorry, I'm still not with this. Who is "he"?

Again, not answering the question but instead introducing another irrelevant distraction. -1.

What cartel is that?

Common sense is a useless guide, in the world of subatomic entities.

Your videos are a waste of time. This has been explained to you before.

Not so far as I am aware. And, from the sound of things, I don't think they would have been very inspiring boobs if they had been.

This is a muddle. Stating what a physical law says is - obviously - not a piece of "enquiry". It's a statement of the conclusions of enquiries. The Second Law of Thermodynamics is a conclusion put forward as a result of scientific enquiry. As previously stated, it has been found, in the course of some 150 years of science and engineering, to be something that is always obeyed, and there has been a very detailed statistical model of how it arises for over a century. You claim to have studied it for years, yet it is plain you do not even understand the relevant concepts, such as entropy, still less its origin in the statistical behaviour of molecules. You seem to think you can override a century and half of experience and theory by futzing around with toy machines and doing your experiments sufficiently badly as to obscure what is happening. That is tilting at windmills.