If you were on a train that was travelling at 60 mph and you threw a ball (inside the train) and the ball was travelling at 10 mph (inside the train), then the ball would objectively be travelling at 70 mph. Any observer (outside the train) would be able to understand why it looks like 10 mph inside the train and 70 mph outside the train.
Are you with me?
Okay, so the same thing does not happen with light! If you turn on a flashlight (inside the train), the light would be travelling at 670,616,629 mph regardless of whether the train was stationary or moving. So an observer outside the train would see the light travelling at the same speed as an observer inside the train. Even if the train was some supersonic invention from the future, the light inside the train would still be travelling at 670,616,629 mph - not 670,616,629 mph plus the speed of the train. And both inside and outside the train, observers would see the light as travelling at that speed. That’s the big thing to get hold of!
How can this possibly be the case?
The answer is that time itself actually slows down when we are in motion. At low speeds, the effect is negligible, but the closer we get to the speed of light, the more the effect becomes observeable, until, when we are travelling at the speed of light, time stands still. If we were able to go faster than the speed of light, we would be travelling backwards through time.
The same thing does happen with light, in that your simple first example does need to consider relativity if you want to be exceptionally precise. It’s not correct to suggest these two scenarios are fundamentally different, where only one needs lorenz corrections. In truth, both scenarios do, its just that the correction is so insignificantly small for the first example that it can be left out without any significant change in the answer.
One observer can see two events happen simultaneously while another sees them happen at different times.
And EVEN WORSE than that, thanks to length contraction at relativistic speeds, you could have one observer think that a train is contained entirely within a tunnel, but another observer sees the train sticking out both ends of the tunnel at the same time without ever fitting entirely within it.
and/or: One observer objectively masures that object A is longer than object B, while another observer objectively measures that object B is longer than object A.
The two observers are not just hanging out together, of course. They are moving ridiculously fast relative to one another.
Yup moving through space faster means moving through time slower. Kinda like if you were traveling at a constant speed through a 2d grid, if you make your vertical speed faster, your horizontal speed would be slower, except replace the grid with spacetime where we’re pretty much always traveling through time at ~1c and space at ~0
I remember learning that if a quasar is spinning fast enough, then the radio waves inside are theoretically traveling faster than light. Which means that some of the star’s mass is actually experiencing time in reverse, until they breach the corona.
If you were on a train that was travelling at 60 mph and you threw a ball (inside the train) and the ball was travelling at 10 mph (inside the train), then the ball would objectively be travelling at 70 mph. Any observer (outside the train) would be able to understand why it looks like 10 mph inside the train and 70 mph outside the train.
Are you with me?
Okay, so the same thing does not happen with light! If you turn on a flashlight (inside the train), the light would be travelling at 670,616,629 mph regardless of whether the train was stationary or moving. So an observer outside the train would see the light travelling at the same speed as an observer inside the train. Even if the train was some supersonic invention from the future, the light inside the train would still be travelling at 670,616,629 mph - not 670,616,629 mph plus the speed of the train. And both inside and outside the train, observers would see the light as travelling at that speed. That’s the big thing to get hold of!
How can this possibly be the case?
The answer is that time itself actually slows down when we are in motion. At low speeds, the effect is negligible, but the closer we get to the speed of light, the more the effect becomes observeable, until, when we are travelling at the speed of light, time stands still. If we were able to go faster than the speed of light, we would be travelling backwards through time.
The same thing does happen with light, in that your simple first example does need to consider relativity if you want to be exceptionally precise. It’s not correct to suggest these two scenarios are fundamentally different, where only one needs lorenz corrections. In truth, both scenarios do, its just that the correction is so insignificantly small for the first example that it can be left out without any significant change in the answer.
Thanks for fucking up my mind so I can’t get anything done at work for the rest of the day lol
Oh it gets even weirder than that.
One observer can see two events happen simultaneously while another sees them happen at different times.
And EVEN WORSE than that, thanks to length contraction at relativistic speeds, you could have one observer think that a train is contained entirely within a tunnel, but another observer sees the train sticking out both ends of the tunnel at the same time without ever fitting entirely within it.
and/or: One observer objectively masures that object A is longer than object B, while another observer objectively measures that object B is longer than object A.
The two observers are not just hanging out together, of course. They are moving ridiculously fast relative to one another.
The speed of causality is a hell of a drug.
I finally feel (kinda) confident with time dilation, and now everyone’s talking about length dilation 😭
Wonder if that applies to my dih
Honey, I’m gonna run real fast, look at how long my digling gets
Wait till you hear about the mind enlargement
So it’s woven with space?
Yup moving through space faster means moving through time slower. Kinda like if you were traveling at a constant speed through a 2d grid, if you make your vertical speed faster, your horizontal speed would be slower, except replace the grid with spacetime where we’re pretty much always traveling through time at ~1c and space at ~0
They are one and the same.
I remember learning that if a quasar is spinning fast enough, then the radio waves inside are theoretically traveling faster than light. Which means that some of the star’s mass is actually experiencing time in reverse, until they breach the corona.
That’s a super interesting idea, but I don’t think it’s actually true. I think it’s in appearance only