But the Wang patent says that there is a preferred reference frame (traditionally called Aether).

Whatever terminology he used in a patent, the effect is consistent with relativity.

”it is impossible to detect motion by measuring differences in the speed of light” (Mantra of the Relativists)

Who says that? I think you've oversimplified this.

Scientific progress comes from critical thinking, not from believing in human creatures.

 "progress". How have geocentrists progressed science in the last 200 years?

What critical thinking have you applied to your "trivial" analysis of Sagnac and Wang devices?
Lots of people have explanations for why the analysis you call "trivial" is a wrong analysis.

Quote from: Struthio

”it is impossible to detect motion by measuring differences in the speed of light” (Mantra of the Relativists)

Who says that? I think you've oversimplified this.

I put it in quotes since it's what relativists say:

https://www.bluffton.edu/homepages/facstaff/bergerd/NSC_111/relativity.html


Don't be hard on them. I could have used another one of these mantras:

"there is no preferred reference frame"

I put it in quotes since it's what relativists say:
https://www.bluffton.edu/homepages/facstaff/bergerd/NSC_111/relativity.html

So, we have a line from a page from a 100-level class at a small college. Is it just possible the line is a little bit simplified?

In particular, as stated it's missing something relevant to the point we're supposedly currently discussing - the SR analysis of a Sagnac or Wang device in the moving frame.

But since you provided the link, I would like you to look near the end of that page at the two points of view for lightning striking a train. This example is similar to the Wang device, which is just a variation on a Sagnac device. And I think the author of the page is trying to present SR.

From S's view (likely named for the Stationary frame), light from the lightning strikes arrives at the same time, and from the same distance away.  Presumably you would agree this means light travels the same speed in both directions from S's frame of reference.

From M's view (the Moving frame), the light from one lightning strike arrives earlier than the other, but they are still both the same distance away, so M interprets that one lightning strike happened before the other.

SR would say light travels the same speed in both directions from M's frame of reference, too. The example suggests, however, that from M's perspective, light went one direction in a shorter time than the other direction, both over the same distance.

1) So does that mean in M's frame light travels faster in one direction than the other?

2) If not, why not? If so, why, and is this a contradiction with SR?

3) What do you think someone following SR would say about this?

In particular, as stated it's missing something relevant to the point we're supposedly currently discussing - the SR analysis of a Sagnac or Wang device in the moving frame.
[...]
This example is similar to the Wang device, which is just a variation on a Sagnac device.

Einstein's train example is about the relativity of simultaneity of events at different locations in space. How is that similar to the Wang device?

It looks like linear motion to me. We can discuss how it applies to Wang's device after you've answered the numbered questions.

No need to discuss Einstein's thought experiment. It's not a matter in dispute. The well known analysis of the situation is in full accord with Special Relativity, not contradicting the postulates.

How could a thought experiment based on the postulates of Special Relativity disprove an experiment which refutes the postulates? You tell me!

Well, humor me then, and apply your critical thinking skills. I said why in the Moving frame, light appears to go faster in one direction than the other. Can you explain why that is wrong?
This is relevant to the point we're supposedly discussing.

I don't agree that light appears to go faster in one direction than the other. There is no measurement of the speed of light involved, neither Susan nor Mary measures the speed of light, so how could light appear to go at any certain speed at all?

Mary sees one bolt earlier than the other based on the assumptions of Special Relativity, which include the premise that light travels at speed c.

The speed of Light is always isotropic and does not depend on the direction in Special Relativity. And this is with respect to any and all measurements of light. Given Special Relativity, light cannot appear to go faster in one direction than in the other, when measured.


Let me remind you of the fact that, within this debate, I am the critic of Special Relativity, while you defend it. Not the other way around. 

Let me remind you of the fact that, within this debate, I am the critic of Special Relativity, while you defend it. Not the other way around.

I am a little surprised by your answer.

M and S appear to be able to say something about the speed of light. To S, the lightning strikes happen the same distance away and light arrives at the same time. So light travels the same speed over the same distance both directions. To M, the lightning strikes happen the same distance away but arrive at different times. This could appear to suggest light did not travel the same speed each way.

But you seem to recognize that within SR, in M's frame, light travels the same speed in either direction. In other words, the train example doesn't exclude SR.

OK, so why not take the train and wrap it around a disk so the lightning strikes are next to each other? The lightning strikes are emitters in a Sagnac device. M is the interferometer. In M's frame, the light from different directions arrives at different times. That would appear to make a fringe shift and the Sagnac effect in M's frame.

So if you accept that it's possible to understand M's frame for the train via SR, why couldn't it also be possible to understand M's frame for the Sagnac loop a similar way?

Do you have any response to my question about Msun squared in Popov's paper?

Also, there are certain effects that relativity explained, so if you did reject relativity, you would need some other way to explain these effects. Two well-known relativity effects are light bending around stars, and the discrepancy in the precession of the orbit of the planet Mercury. The latter is almost entirely explained by general relativity (or one of the alternative theories that include the same predictions). I'm not saying SR/GR don't have some issues, but they explain several things. Any subsequent theory will likely need to include SR/GR as limiting cases, like Newtonian physics was a limiting case for SR.