jamesfairclear

Can I then consider the angular momentum of the electron to be an invariant quantity (like c) such that it will be the same value regardless of whether the body is relatively stationary on Earth or moving away from Earth at 0.99c?

Would you expect the quantity (the speed) of angular momentum to vary?

Considering an atom within a rigid body, does the angular momentum of an electron within the atom vary when the body is put in motion?

By relatively stationary I mean that the detector is for example on Earth at a location on the equator and the emitter is receding at a velocity v along the equator. It is of course a principal of SR that the speed of light is invariant but my interest is in finding experimental evidence of this invariance measured with a receding light source.

GPS supports the invariance of light speed in a given IFOR but not for a receding light source. I wouldn't agree that performing experiments in a single IFOR necessarily confirms the behaviour in multiple IFORs especially when we can already confirm that one property of light (the wavelength) behaves differently with a receding light source.

I don't doubt the mathematics. My interest is in finding experimental evidence to substantiate that light from a receding light source travels at c to a relatively stationary destination. Have you come across such an experiment?

It should work ok. The light source is set in motion at a constant speed S and then illuminated at a distance D from a relatively stationary detector. The illumination of the light source could either be triggered by coinciding with a relatively stationary device at distance D or via an onboard clock that calculates distance D. Thus we know exactly when the light source has travelled a distance D from the detector (t1) and the clock at the detector begins measuring time from that moment. Theoretically the one way speed of light is the same as the 2 way speed. However there has been a lot of debate about this over many years. I am specifically interested in measuring the speed of light from a receding light source. We know that the motion of the receding light source affects the wavelength of light received at a relatively stationary destination but I am looking for any experiments that have conclusively proven that it does not affect the speed of propagation. That is a interesting point. However I would have thought that the only potential issue would be extremely minimal doppler shift which probably wouldn't be sufficient for there to be any audible artefacts. Any variation from c of the speed of the radio waves reaching the car aerial would be insignificantly small to make any audible difference.

Thank you for your response. Your assumptions are correct. One could envisage an experiment whereby a light source is set in motion at a constant speed S and then illuminated at a distance D from a relatively stationary detector. A clock at the detector measures the time it takes the Doppler redshifted light to arrive from distance D in order to establish its speed. Are you aware of an experiment of this type that has explicitly measured the speed of Doppler redshifted light emitted from a receding light source?

My understanding is that Doppler redshifted light received at a relatively stationary destination from a receding light source is still deemed to be travelling at the same speed of c as light arriving from a relatively stationary source. Has this been experimentally verified and if so how?

There is a sequence of events counted by each clock. The clock itself cannot detect anything between each event because there is nothing to detect. Equally a human observer cannot detect anything between each event but can elect to assume notionally that there is an imaginary interval between events and characterise it as a flow of time even though there is nothing that can actually be observed. The alternate interpretation does not preclude making reference to Time for the sake of convenience. Thus we can refer to a measurement of 10 seconds or N events for a given observation. The alternate interpretation differs in that it proposes a different model substituting Time with a quantity of events. As previously stated the alternate interpretation is evidenced by any of the copious experiments that have substantiated Time Dilation. For example taking an atomic clock up in an aircraft , flying around the globe, returning to its starting point comparing its reading to that of a stationary clock located at the starting point. The difference in the readings substantiates that motion reduces the quantity of events.

This alternative interpretation is evidenced by the same evidence that substantiates Time Dilation in SR.

The notion of Time is a measurement of a quantity of events and an event cannot be undone. Thus the notional arrow of time can only be in one direction.

The sequence of events in the experiment is:

No. SR predicts that time dilates in a moving inertial frame of reference. This experiment can be interpreted as either substantiating Time Dilation or substantiating a reduction in the frequency of events. All calculations relating to Time dilation remain the same except that time is substituted with a relative Frequency of Quantum Events. Atomic clocks are highly predictable in that the decay events they count are highly predictable but significantly decay events are not totally predictable. Thus 2 atomic clocks side by side in the same stationary location will count very slightly differing numbers of events.

The experiment is done without making any assumptions about time. The numbers displayed on each clock are the numbers of decay events registered in the experiment. The numbers are tied to quantities of events not time and do not change arbitrarily.