3 ms·

I think it's like this: Time stands still for the photon and is super slow for the particle. Super slow is still infinitely away from 0. In the article example

by dlwdlw 9y ago

I think it's like this: Time stands still for the photon and is super slow for the particle. Super slow is still infinitely away from 0. In the article example from the particles view, 0.000..1 seconds pass for the photon to be 1cm ahead being the photon is so fast. From our view however that same small time is dilated to the 200k years.

ptrincr 9y ago
This is all true.... However it should be said that time is not super slow for the particle, from the particles point of view (frame of reference) time passes as per normal for itself. This is what allows the photon to appear to continue to travel at the speed of light from the particles frame of reference. If the particle was carrying a clock, and we could watch it tick as it flew away from us, it would appear to be ticking super slowly, the second hand would take forever to move. Conversely if we had a giant clock and the particle could watch it as it flew away from us, it would appear to be ticking super fast, it would look as though we were travelling far into the future. The same is also true if an object is close to a very large gravity well. If someone could stand next to the event horizon of a black hole and hold a giant clock, from our point of view, their clock would appear to tick very slowly. From their point of view, it would tick normally, but our clock would rapidly tick far into the future. The universe around them would quickly travel into the future. Time and space are elastic to allow the speed of light to remain constant.
Nition 9y ago
There's something I don't understand about that type of explanation. Say a particle and I are moving along like so: -----[photon @ speed of light]--> -----[me @ 50% speed of light]--> Or more simplified, say two cars are moving like so: -----[other car]--> -----[my car]--> When I'm stationary, I see him go past at 100km/h. When I move at 50km/h, in the real world he would now appear to only be going 50km/h. But if I slow down my time to half speed, now he'll look like he's going 100km/h again. Because he looks to me like he's at 50km/h at double time speed = 100km/h. That seems to make sense - time slows down and the apparent speed stays at C (100km/h in this case). That's how I've understood the explanation for relativity. But it must be a very wrong understanding - because that whole idea breaks down when the other car is going along a different vector to me! In this situation: <----[other car @ 100km/h]-- -----[my car @ 50km/h]--> His speed relative to me would come out as 150km/h in the real world, and no amount of making him look like he's going faster would reduce his speed to 100km/h.
- deleted 9y ago
  [deleted]
- ptrincr 9y ago
  The reason is Lorentz transformation: https://en.wikipedia.org/wiki/Lorentz_transformation https://en.wikipedia.org/wiki/Lorentz_transformation Your measurement of time and space will always adjust to ensure light travels at a constant speed. Time dilates, length contracts. So perhaps it would "look" like the car travelled a smaller distance over a longer period of time that what you expected, from your frame of reference, versus a third observer who can see you both.
  - Nition 9y ago
    Thanks, that looks like what I'm talking about and I'll have a read through. It looks like pretty dense reading but the equations mostly don't look too horrible.
  - posterboy 9y ago
    > Your measurement of time and space will always adjust to ensure light travels at a constant speed. Enough with the metaphors already, the measurements don't do anything, you, or rather phyisicists and the like do measurements, and they adjust numbers normalized to c=1 because how else would you do it. There is no way to synchronize clocks because of the CAP theorem, nevermind relativity.

by dlwdlw 9y ago

ptrincr 9y ago

This is all true.... However it should be said that time is not super slow for the particle, from the particles point of view (frame of reference) time passes as per normal for itself. This is what allows the photon to appear to continue to travel at the speed of light from the particles frame of reference. If the particle was carrying a clock, and we could watch it tick as it flew away from us, it would appear to be ticking super slowly, the second hand would take forever to move. Conversely if we had a giant clock and the particle could watch it as it flew away from us, it would appear to be ticking super fast, it would look as though we were travelling far into the future. The same is also true if an object is close to a very large gravity well. If someone could stand next to the event horizon of a black hole and hold a giant clock, from our point of view, their clock would appear to tick very slowly. From their point of view, it would tick normally, but our clock would rapidly tick far into the future. The universe around them would quickly travel into the future. Time and space are elastic to allow the speed of light to remain constant.

Nition 9y ago

There's something I don't understand about that type of explanation. Say a particle and I are moving along like so: -----[photon @ speed of light]--> -----[me @ 50% speed of light]--> Or more simplified, say two cars are moving like so: -----[other car]--> -----[my car]--> When I'm stationary, I see him go past at 100km/h. When I move at 50km/h, in the real world he would now appear to only be going 50km/h. But if I slow down my time to half speed, now he'll look like he's going 100km/h again. Because he looks to me like he's at 50km/h at double time speed = 100km/h. That seems to make sense - time slows down and the apparent speed stays at C (100km/h in this case). That's how I've understood the explanation for relativity. But it must be a very wrong understanding - because that whole idea breaks down when the other car is going along a different vector to me! In this situation: <----[other car @ 100km/h]-- -----[my car @ 50km/h]--> His speed relative to me would come out as 150km/h in the real world, and no amount of making him look like he's going faster would reduce his speed to 100km/h.

deleted 9y ago
[deleted]
ptrincr 9y ago
The reason is Lorentz transformation: https://en.wikipedia.org/wiki/Lorentz_transformation https://en.wikipedia.org/wiki/Lorentz_transformation Your measurement of time and space will always adjust to ensure light travels at a constant speed. Time dilates, length contracts. So perhaps it would "look" like the car travelled a smaller distance over a longer period of time that what you expected, from your frame of reference, versus a third observer who can see you both.
- Nition 9y ago
  Thanks, that looks like what I'm talking about and I'll have a read through. It looks like pretty dense reading but the equations mostly don't look too horrible.
- posterboy 9y ago
  > Your measurement of time and space will always adjust to ensure light travels at a constant speed. Enough with the metaphors already, the measurements don't do anything, you, or rather phyisicists and the like do measurements, and they adjust numbers normalized to c=1 because how else would you do it. There is no way to synchronize clocks because of the CAP theorem, nevermind relativity.