Is Proper Time=0 Equivalent to Saying Proper Time Doesn't Apply?

[Nick666]

From what I know, the laws of physics being the same in all referential frames is usually interpreted with specific examples where if in one frame a rope breaks that means that it must break in all other reference frames, so I'm trying to understand how does a non-existing referential frame agree with the fact that in our reference frame the photon has certain laws.

 

[jbriggs444]

From what I know, the laws of physics being the same in all referential frames is usually interpreted with specific examples where if in one frame a rope breaks that means that it must break in all other reference frames, so I'm trying to understand how does a non-existing referential frame agree with the fact that in our reference frame the photon has certain laws.

The claim that "the laws of physics are the same in all inertial reference frames" entails no prediction whatsoever about what the laws of physics are like in non-existent reference frames.

 

[Nick666]

entails no prediction whatsoever about what the laws of physics are like in non-existent reference frames.

So then how come we from our frame of reference know or are so convinced that our laws of the photon are true ? (I sense maybe its a stupid question but I had to do it)

 

[Ibix]

The principle of relativity itself implies an invariant speed. If that speed is infinite you get Newtonian physics. If it is finite you get relativistic physics.

See http://arxiv.org/abs/physics/0302045.

 

[jbriggs444]

So then how come we from our frame of reference know or are so convinced that our laws of the photon are true ? (I sense maybe its a stupid question but I had to do it)

Our laws are our laws. They apply to all objects, including photons. How a hypothetical photon would make up a hypothetical law of physics to hypothetically describe how things look from its hypothetical point of view is irrelevant. The photon is not telling us what it sees.

 

[Nugatory]

Just so I don't open another thread.

If the photon doesn't have a referential frame, and relativity says the laws of physics are the same in all referential frames, can't one say that the laws of physics are ...not...the same for the photon ?

No, because when someone says "the laws of physics are the same in all reference frames", they are being a bit sloppy with the English language. It would be more accurate (but sounds clumsier, which is why we don't often say it this way) to say "The law of physics produce the same results no matter what reference frame you use to assign times and positions to events". Phrased this way, it is clear that the aws of physics apply to everything, whether we can find a reference frame in which it is at rest or not.