Strange

I wish I had thought of that!

I assume the"nail" is made of some sort of frozen mixture of water and the stone is warm.

Do you mean optical aberration (the inability of a lens to focus) or astronomical aberration (the fact that the apparent position of stars changes with the speed of the observer)?

That's fine. I am just trying to clarify exactly what the setup and results are. Some of your comments about what you see are slightly ambiguous so it is hard to comment without being absolutely clear about what results you are getting. But I realise drawing a diagram and posting it is a lot of work so ... When you say you couldn't see it from above except when reflected by the mirror, is that because you couldn't get to a position where you were looking down? The mirror shouldn't make any difference. It is, I assume, only there so the light scattered sideways and the light scattered vertically can both be seen from the same place. (Is that correct?) So I am slightly puzzled by the fact you can see the light scattered vertically in the mirror but not when viewed directly. I would be very surprised if most of the beam did not pass through the water like this. Unless the water is very murky, only a small proportion will be scattered. This might be changed slightly for polarised vs unpolarised light, but should be the same for vertically or horizontally polarised light. That is very ambiguous. It is not immediately clear what it means and I can imagine at least two interpretations - and that might change depending on where the mirror is. I am not making any accusations. Just trying to clarify what you see and what you are still questioning (if anything). If you get the same result as Bragg and you are happy with the explanation of why polarised light is scattered differently depending on the angle of polarisation, then we are done. If you are still puzzled by the results, then we can explore that as long as you can be clear about what your setup is and exactly what results you get.

That has nothing to do with gravitational lensing.

I think only if there were significant accretion disks. I'm not sure if/why that is considered unlikely for merging binaries.

So I assumed everything was clear. But ... Does this mean that you could always see the (scattered) light from all sides and the top, but you couldn't see it in the mirror even though the mirror is angled so it is the same as you looking down? In other words, when you look down past the mirror you can see the light, but when you look in the mirror you can't? That doesn't make much sense. Maybe the mirror just isn't aligned to see the path of the light? Perhaps you could provide a drawing & description of your setup?

Well, his idea of a dark star was based on the idea that light could not escape because the escape velocity of the star exceeded the speed of light. This does give the same radius as the event horizon of a black hole (+1 for Mitchell) but does mean that light could escape temporarily - in the same way you can throw a ball in the air at less than the Earth's escape velocity. This would cause observable effects. In the case of a black hole, the event horizon is completely inescapable. Also, it isn't clear that light would actually be affected in the way described by Newtonian gravity (Mitchell assumed that light was made of particles that would be affected by gravity). But it is only of historical interest as we now have a more accurate theory of how gravity works and how it affects light. Light never stops. It just gets fainter, so there is no limit to the distance it can travel. Light gets increasing red-shifted. But we can still detect it. And other frequencies get shifted into the visible range. Just found this: https://en.wikipedia.org/wiki/Dark_star_(Newtonian_mechanics) Apparently, Mitchell and Newton got gravitational redshift the wrong way round as well. And the amount of gravitational lensing.

Allegedly? "subjectively"

It is called "perspective". Perspective is very conventional.

Nothing much. It was remarkably good, considering it was based on a flawed theory! One possibility for dark matter is micro-black holes. The problem is that if there were enough black holes to provide the extra mass then we would probably see them (because they would travel in front of other stars and block our view of them). They would also cause gravitational lensing, which should be detectable as well. We have a model based on the physics of stellar fusion that explains supernovas. Colliding black holes don't produce the same effects. Colliding neutron stars produce much larger explosions. In principle, never. But in practice it depends on the brightness of the star and the size of the telescope. We can see stars (well, galaxies) that are nearly 13 billion light years away.

Nice. (But I guess when people say "the laws of physics" they mean our models. Usually.)

Energy is energy. And fermions are not necessarily stationary - they are just constrained to speeds less than c. The same is true for bosons with mass, of course. A photon cannot be stationary. And it can't become a fermion. That would violate several conservation laws. You can't. But it would still be a photon. And therefore travelling at c relative to you. (Which is why the thought experiment makes no sense.) I don't think that is the purpose of the Speculations forum.

They are not electromagnetic waves. Apart from that, I'm not sure what you are asking. Why would translational velocity be relevant? Also, could your provide a reference for your quoted text.

Every example of refraction on Earth, in space, on the Moon, on Mars and probably elsewhere. There is nothing magic about prisms. They just exploit refraction and dispersion. "Oh yes, they may all give the same results, but what about doing the same experiment on a wet Saturday while wearing Dangermouse underpants?"

It is not an assumption, it is a conclusion from the evidence. It could, of course, turn out that the conclusion is wrong but that would require evidence. It is a theory, in that it is supported by lots of evidence. (Phrases like "just a theory" always ring alarm bells, BTW.) It could be that it is wrong. And, of course, many people have tried to use the evidence from galactic rotation curves, for example, to support alternative theories gravity. So far, none of the alternatives work as well as the accepted theories. While you are right to say that our theories should be continually tested (as they are) there are probably more significant concerns than whether refractive dispersion depends on which planet you are on. After all, if you could be shown that one of the spectrometers on Mars used a prism (and it behaved as expected) then you could just say "but what about Mercury? Or Venus? Jupiter? Saturn? All of the exoplanets? The planets we haven't found yet? Other galaxies?" At some point, you have to accept that we have a lot of evidence and a theory to explain the evidence. Yes, science is always provisional, but you seem to be taking that doubt to extreme degrees. You might ask what Newton had for breakfast when he did his experiment. Would that make a difference? Unless we test it, we won't know. And what day of the week was it? Which socks was he wearing? Was it before or after he invented the cat flap?

But they tell you the same thing about the elements on Mars as they do on Earth. Therefore they behave the same way. But I don't understand what you expect to be different (or why) so I have no idea if the fact that a prism behaves the same way on Earth and Mars actually answers your question as to whether a prism would behave the same way on Earth and Mars ....

Some spectrometers use prisms. Others use diffraction gratings. They all use optical dispersion. There is no reason to think that electromagnetic waves behave differently on different planets.

And you expect a prism to behave differently but a spectrometer not to? What is the theoretical justification for that?

https://mars.nasa.gov/mer/mission/spacecraft_surface_instru.html

I don't think I have attacked anyone. But feel free to report the relevant posts to the moderators. You asked if a prism (which is basically the same as a spectrometer) would work the same way on Mars. The answer is yes. Because they are in use there. Why does that not satisfy you.

Not as far as I know. But we don't know what happens in a black hole, especially near the centre. We probably need a theory of quantum gravity to answer these questions. Mass and energy are interchangeable, as far as gravitation is concerned. So if it is massive particles or photons with the equivalent energy makes no difference to the mass of the black hole. Again, not according to current theory (GR) but that may change with a theory of quantum gravity. Gold and other heavy elements were observed in the recent neutron star collision. So, yes, it appears so. Again, not according to current theory (GR) but that may change with a theory of quantum gravity. No one knows.

Burden of proof. You claim the theory is wrong. It is up to you to actually demonstrate this is the case. Drawing made up diagrams won't do it. I could draw a diagram of a free falling lift with someone juggling kittens in it, and claim it disproves the equivalence principle behind GR. But obviously it doesn't.

Spectrometers have been used on Mars. Why deny it? Asking random questions based on misunderstandings and lack of knowledge is probably not the most productive route. A structured course would be far more effective. You can find lots of free courses on line. Or go old school and buy a book.

Yep. Please show your working.