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komor555 t1_j1je8zi wrote

Reply to comment by mayonnace in Are people in the international space station experiencing time faster than us? by [deleted]

If you'd travel at the speed of light, time would stop for you relative to the universe completely. Accelerating faster you'd be going back in time, in theory. I don't know the relationship between time and light, but I suspect that light has to follow the same rules as everything else that has a mass and travels.

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mayonnace t1_j1jmdjt wrote

That's weird. If I was a photon, trying to travel from a lamp on Earth to some very far away planet, you say, time would stop for me. But if time stops, there can't be motion, and I would never leave from that lamp on Earth in the first place. I would just glimpse into existence, and stop forever, or something like that.

Or I guess you mean like, everything stops, but me. In that case, my birth into existence and arrival on my final destination would be instantaneous. I'd get born, travel, and die at the same time.

Ooooor, that would be how everything else would see me as, happening instantaneous, while I'm actually having lots of fun during my travel, seeing how nothing is moving, perhaps except other photons. Is that it? But this couldn't be true either, because we don't see light's movement instantaneous, we see it with a delay depending on its distance, like we keep seeing old stars that aren't there anymore...

It doesn't make sense. Sorry. Perhaps I shouldn't have put myself in place of a photon. I don't know.

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I__Know__Stuff t1_j1jo0or wrote

> my birth into existence and arrival on my final destination would be instantaneous. I'd get born, travel, and die at the same time.

This is correct. To an outside observer (us), it takes a photon about 8 minutes to travel from the sun to the earth. To the photon itself, it is instantaneous.

One of the ways that it was determined that certain neutrinos have mass is that there is a nonzero probability of them mutating while they travel between the sun and the earth. If they had zero mass, they would travel at the speed of light, and there would be no passage of time during which they could mutate.

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mayonnace t1_j1jr7ki wrote

I see, but that's weird.

In this sense, if this time-speed relation is continuous, the faster a thing will move, the less time flow it will experience. And as someone else suggested, if one could accelerate further, then it would have to see things going back, but that confuses me and it's another story, because me accelerating further would require me being observed as going backward too, but I'd be going the same direction... Then perhaps it's an automatic thing that, after this speed limit, the direction of the vector just rotates itself backwards? But that doesn't sound nice either.

I guess we will have to assume, speed of photon is the maximum, and zero is the minimum, and there can happen no bending beyond these extremes due to some dimensional restrictions or something.

Then, in a similar sense, something with zero speed, should experience the whole time being as fast as a moment, like the cosmos gets born and dies at the same time, yet it might have to stay still at the center of the universe for that, because its coordinates should never change to never have any speed, and at the beginning it was a point, I guess.

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feral_engineer t1_j1kddjk wrote

When time stops it stops in a reference frame. There is no motion in that reference frame but the frame can still move through spacetime relative to other reference frames. Think of light as a permanently frozen object. It pops into existence and does not change. It can still move through spacetime. The concept of instantaneousness does not apply to frozen objects. They don't experience time ever.

Similar to motion, a reference frame where time stopped can spin. That's how the singularity in a black hole behaves. Time is stopped in it but it still spins. When matter falls into the black hole angular moment adds up so it can spin up or spin down while still experiencing no time (remaining frozen).

Note that light frequency is not a movement in addition to the movement of light along geodesic lines. A frozen object can have internal frequency, spin, and momentum.

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whatissevenbysix t1_j1jp06b wrote

You actually got it. From a photon's perspective time doesn't exist. It instantly comes into existence and dies at the same exact moment.

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