Light clock treating horizontal and vertical motion differently?

[Ibix]

I think it's also worth noting the existence of the so-called "one postulate" derivations of the Lorentz transforms, which only assume the principle of relativity. They do not use the light speed postulate, so cannot be said to assume anything special about any speed. They show that there are only two systems of physics that are consistent with the principle of relativity - the Galilean transforms and the Lorentz transforms but with an unknown finite invariant speed in the place of the $c$ that you get if you do use the second postulate. You would then use an experiment like Bertozzi's to show that we don't live in a Newtonian universe and that the unknown finite invariant speed is actually $c$, or observe that the invariant speed has to be $c$ for Maxwell's equations to be covariant.

Bertozzi's experiment:

 

[Dale]

Or zero-postulate derivations (not what they call themselves) that don’t assume either postulate and simply use experimental evidence instead.

 

[Ibix]

Or zero-postulate derivations (not what they call themselves) that don’t assume either postulate and simply use experimental evidence instead.

You're thinking of stuff like Poincaré's 1904 paper, which has the complete maths of SR collected from empirical study of electromagnetism without him quite realising what he'd got?

 

[Dale]

You're thinking of stuff like Poincaré's 1904 paper, which has the complete maths of SR collected from empirical study of electromagnetism without him quite realising what he'd got?

I didn’t know about that one. I was actually specifically thinking of Robertson’s paper “Postulate versus observation in the special theory of relativity”. He shows that, without assuming either of the postulates, we can infer the Lorentz transform to about 1% accuracy from just the Michelson Morley experiment, the Kennedy Thorndike experiment, and the Ives Stillwell experiment

 

[sophiecentaur]

The question I had is based on whether artificial distinctions are being made between different types of motion because people are looking for a certain answer.

Physics has the luxury of the availability of very reliable and repeatable experiments. Whatever outcome people are "looking for" the answer from a well designed experiment gives what it gives and we rely on the result until someone comes up with a well supported alternative theory. That's unlike what politicians do: Quote from a UK education minister "We are gong to do a survey to show that . . . . ."

Scientists do experiments to find out if . . . . .

Motion can be classified, either as inertial or non-inertial. This thread is about inertial motion and there's only one of those.

 

[Herman Trivilino]

That's unlike what politicians do: Quote from a UK education minister "We are gong to do a survey to show that . . . . ."

Scientists do experiments to find out if . .

One time at a department meeting the chair declared that some educational data we'd collected was "bad" because it didn't show the desired result!

 

[FactChecker]

The question I had is based on whether artificial distinctions are being made between different types of motion because people are looking for a certain answer.

"artificial distinction"? What??!! Riding fast in a car, can't you tell tell the difference between smoothly going straight and going around a curve?
IMHO, there is something strangely wrong about this entire thread.

 

[Herman Trivilino]

In every example I have seen using the light clock, the moving observer is considered to be moving relative to the entire light clock,

In this scenario is the clock at rest?

There are an infinite number of reference frames for which your example is true, and those reference frames could be in motion relative to each other. Observers at rest in each of these frames could measure the clock moving at different speeds.

So, there is nothing absolute about the speed of the clock. It's value is not a property of the clock. It's a property of the relative motion of the observer.

whereas the light beam is considered to be moving from one part of the apparatus to the other.

The light beam is in motion regardless of this consideration. So how is it relevant?

But if the light clock was picked up and thrown, the entire clock would move, regardless of whether it was thrown horizontally or vertically.

Whether the clock moves or not, or in what direction, is a property of the relative motion of the observer.

So why is the motion of the light beam being treated differently?

The motion of anything moving at light speed is treated differently. Nature seems to behave in such a way that to make accurate predictions of that behavior we have to treat that particular speed that way. In others words, currently accepted theory treats light speed that way because that's the theory that's most successful.

You could create a different theory, but if you wanted to discuss it here you'd have to follow the forum rules, which would probably require that you first get your theory published in an accepted peer-reviewed journal.

 

[FactChecker]

In every example I have seen using the light clock, the moving observer is considered to be moving relative to the entire light clock

I disagree. IMO, most of the explanations compare a "stationary" light clock to a "moving" light clock. The experimental result that the light in the two clocks travel the same speed, measured in each clocks IRF, leads to the results of time dilation and distance shrinking.
The confusion possibly comes from the fact that the explanation concentrates on how the "stationary" observer interprets what is going on with the measurements of the "moving" light clock in the "moving" IRF measurement system.