So on several websites, including phys.org and physics.stackexchange, I have read that photons do not experience time. And that if you travel at the speed of light, time and distance shrink to 0.
Is this really the case? Or is this simply one of those analogies gone wrong type thingy?
If this is the case, I have a couple of questions:
- If light emitted from a star x lightyears away reaches earth, has it truly not experienced time, or any change?
- Does this mean that from its point of view, as soon as it left x, the earth was already there? This seems very counterintuitive, since then for light the future is already set in stone, leading to a deterministic universe?
- What happens if at the time it leaves x, I put something in its path to earth? Yet before it reaches it, I put it away again. Will that object never have existed? How does it deal with the time it took me to put the obejct there and remove it?
- Given 3, is there simply no space and time between begin and endpoint? Does it simply not exist between these points?
- Since speeds are relative, one could just as easily take a perspective that the photon is fixed in space and everything else is moving relative to it.. So where does from its perspective the earth get its energy from to attain this speed?
- What is a good book to read on relativity, or about the maths needed to understand this? Because I get a feeling it's always the case that the explanations are faulty when there was no math involved.
- Can we even take the reference frame of a photon? Because since it appears if we can it would lead to all these problems above, so I'm guessing for some reason we can't? If so, why not?
Feel free to answer one, multiple or all questions. I'm not afraid of math although my understanding is lacking, so explanations in that regard would be much appreciated. :)
Bonus question (really out there and more philosophical what-if than semi-serious pondering): 8. If all reference frames are equally valid (perhaps not the photon), and assuming spacetime is grainy at the planck scale, could this not lead to an apparent continuous spacetime since all dilations and contractions would be equally valid? In a sort of integer to rational numbers type difference?
