Explore Alternative Interpretations of Special Relativity

[Charlie K Trout]

TL;DR Summary

Could there be issues with our current understanding of special relativity? With a constant speed of light, does that allow for both time dilation and length contraction at high speeds, or could only one of these be occurring? What alternative interpretations of special relativity have you come across?

A few years ago, a nuclear engineering professor explained to the class that the widely accepted theory between the relationship between space, time, and velocity may be wrong. At the time, I didn't think much about it since he had a lot of out-there beliefs and he seemed to be a bit of a contrarian. However, I still feel the need to explore some possible "alternative interpretations" to what might be going on in reality.

Lately, I've been wondering how we can concretely say that both time dilates and length contracts as velocity increases. Assuming the traditional definition of velocity (v=dx/dt), if length contracts as velocity increases, that would explain how an object can move through space as though time has slowed relative to the observer. On the other hand, if time slows as velocity increases, it could appear to an observer as though space has contracted around the object. For one to be true, the other doesn't necessarily have to be true as well. A constant speed of light, c, can be explained by dx approaching 0 or dt approaching infinity. So, could it be possible that either time or space is constant?

What other "alternative interpretations" to special relativity have you folks come across in the world of physics? How can you determine the validity of those interpretations?

Side note: I know there is the famous atomic clock on a satellite experiment, but I'm trying to look at this from a more conceptual/theoretical perspective. Plus, my contrarian professor suggested that the subtle differences in measured time may be due to various kinds of interference involved in the experimental setup, and I don't know enough about the experiment to validate or invalidate this claim.

 

[PeterDonis]

Could there be issues with our current understanding of special relativity?

I'm not sure what you mean by "issues". SR has been confirmed, within its domain of applicability, by a massive amount of experimental evidence.

With a constant speed of light, does that allow for both time dilation and length contraction at high speeds, or could only one of these be occurring?

No. Time dilation, length contraction, and relativity of simultaneity all go together in SR; you can't have anyone of them without having all three.

What alternative interpretations of special relativity have you come across?

The only known alternative interpretation in the literature is Lorentz Ether Theory (LET). If you review the PF rules, you will see that there is a specific rule prohibiting discussion of LET: we have found that discussions of it here on PF simply aren't productive.

I know there is the famous atomic clock on a satellite experiment

I'm not sure which experiment you are referring to, but clocks on satellites require both special and general relativity to correctly predict their readings. In any case, such experiments are by no means the only ones confirming the predictions of special relativity.

my contrarian professor suggested that the subtle differences in measured time may be due to various kinds of interference involved in the experimental setup, and I don't know enough about the experiment to validate or invalidate this claim.

If your professor has published a peer-reviewed paper about his claim, we can discuss that here. Or if you have specific questions about a published peer-reviewed paper describing the experiment in question, you can post them here. But we can't discuss vague claims from someone who isn't even posting here and can't back them up with a published paper.

 

[robphy]

I think one may have distinguish an “interpretation” from a “violation”
of special relativity.

To me it seems, Interpretation means you accept the results but you may have a different explanation or point of emphasis.
Is the Lorentz group more fundamental than the causal structure? Should measurements be with clocks and rulers? Or radar measurements?
Should one think of quantities that transform (like space and time components)? Or think of geometrical objects (like 4-vectors)?
Etc...

To me it seems, a violation means that some fundamental equation does not correctly describe or predict the experimental result.

possibly interesting:
https://en.m.wikipedia.org/wiki/Modern_searches_for_Lorentz_violation

 

[PeroK]

A few years ago, a nuclear engineering professor explained to the class that the widely accepted theory between the relationship between space, time, and velocity may be wrong.

If your "contrarian" professor had suggested that the Earth might be flat, what would you have thought?

 

[A.T.]

I think one may have distinguish an “interpretation” from a “violation” of special relativity.

Exactly. What the OPs-professor suggests sounds more like a violation. What the OP talks about could just be a different interpretation of the same math.

 

[Ibix]

Experimental evidence for SR is linked from this thread, pinned at the top of this forum.

As others have noted, there's a difference between interpretations and violations of a theory. Lorentz Ether Theory is an alternative interpretation, providing a different explanation for all the same measurable phenomena. You can use it perfectly well, but it's more complicated, isn't really taught anywhere (as far as I'm aware), and doesn't change anything.

On the other hand, a violation of a theory would be experimental evidence that could not be reconciled with that theory. Within the limits of SR (no significant effects due to gravity) we've never seen such a thing. "Interference involved in the experimental setup" is a cop-out. He needs to specify ways that all (or at least a significant minority) of the experiments in the link above can be subtly wrong so that they give answers consistent with the same wrong theory.

 

[Dale]

Summary:: Could there be issues with our current understanding of special relativity? With a constant speed of light, does that allow for both time dilation and length contraction at high speeds, or could only one of these be occurring? What alternative interpretations of special relativity have you come across?

I've been wondering how we can concretely say that both time dilates and length contracts as velocity increases. Assuming the traditional definition of velocity (v=dx/dt), if length contracts as velocity increases, that would explain how an object can move through space as though time has slowed relative to the observer. On the other hand, if time slows as velocity increases, it could appear to an observer as though space has contracted around the object. For one to be true, the other doesn't necessarily have to be true as well

In order to have the speed of light be invariant it is necessary to have both time dilation and length contraction. The issue is that a length can be oriented parallel to the direction of travel or perpendicular to the direction of travel whereas time cannot. In order for the speed of light to be invariant in all directions you need both.

There is another transform called the Voigt transform which also preserves the invariance of c. It has time dilation, but it also has transverse length expansion rather than longitudinal length contraction. However, it violates the first postulate and is ruled out by experiment. But I mention it here because even this transform still requires both a modification of time and also a modification of length. Both are necessary.

Regarding the rest of your post, we need something concrete to discuss. Vague references to a contrarian professor are not feasible. So with that we will close this.