Recent content by robwilson

The OP considers that this thread has outlived its usefulness. I thank those people who provided useful responses. Those from physicists and engineers trying to teach a group theorist how to do group theory were not useful, and were frankly insulting. Those from people unwilling to distinguish...

More or less. I wouldn't say I'm necessarily claiming that, but I am asking the question, and I'm asking for the experimental evidence for whatever answer is provided. So far, I don't find the experimental evidence for the Lorentz group particularly convincing, when compared to the other groups...

Yes. In a way, that is my point.

That is a good summary of my thinking. But we are in danger of violating the forum rules if we continue this discussion here.

I am not doubting its validity within its domain of applicability. I am doubting its universal validity because there are experimental anomalies which cast doubt on it. The various answers on this thread confirm that my impression of the status of the Lorentz group in physics is accurate. I...

Yes, you keep telling me things I know perfectly well, that are not relevant to the question I asked.

On the contrary, I am not missing that point - I have been making that point repeatedly! Interesting that your point of view is that reality is an approximation to the model. My view is that the model is an approximation to reality! Anyway, we're going round in circles. It's probably time to...

I do know that. I also know that there are other groups that can also be built from one-parameter subgroups of Lorentz transformations. The local structure of a group does not determine the global structure.

Exactly. A whole load of simplifying assumptions. I am not interested in a simplified approximate local answer. I am interested in a mathematically consistent globally correct answer. SR and GR taken together do not provide that.

As usual, you are assuming the Lorentz group is the correct group in which to calculate. I don't find this group well-motivated, and I am not convinced that its conclusions are necessarily exactly correct (although clearly they are very nearly correct in a very wide range of experimental...

A distinction without a difference, I'm afraid. If observers 2 and 3 are traveling at constant velocities with respect to observer 1, in different directions and at different speeds, then observers 2 and 3 are rotating around each other according to observer 1. So yes, you can transform to a...

I have no problem with Galilean transformations. The question is, what group do you need if you want the speed of light to be finite and the same for all observers. The Lorentz group is a good approximation, but is it good enough?

Thanks for this elucidation, and especially for the very helpful reference to the wikipedia article on Thomas-Wigner rotation. I note in particular the prominent sentence near the beginning: "There are still ongoing discussions about the correct form of the equations for the Thomas rotation in...

Thank you for this detailed and helpful explanation. I've selected a few places where you use words like "obvious" or "assumption" for analysis. I feel there are gaps in the argument in one or two of these places, such as the one pointed out by PeterDonis. In particular, the conclusion that the...

Yes, many questions. I just want a group that describes the symmetries that experiment reveals. I'm not happy with the groups that are in the current theories, and I've tried many alternatives, which I am not happy with either. Questioning the Lorentz group and the structure of spacetime is more...