this post was submitted on 03 Sep 2024
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Today I Learned

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[–] INeedMana@lemmy.world 2 points 2 months ago (1 children)

It’s popular to think of those things as like crazy high G turns but they’re not. You’re just flying in a straight line through space time.

Soooo... Interstellar was wrong with all the shaking of the camera?

Are you on earth or is the ship in space accelerating at a constant rate? Again, there’s no way to tell. They are, physically, the same.

In case of accelerating ship, I wonder what would happen in local frame once you hit/get really close to c. You'd get decelerated out of nowhere? Just as if you hit something?

[–] VoterFrog@lemmy.world 3 points 2 months ago (1 children)

Soooo… Interstellar was wrong with all the shaking of the camera?

All for the cinematography :) I will say that there's a small caveat in really extreme situations like close to a black hole. Spacetime gets so warped there that your head and your feet take very divergent paths through spacetime, enough to stretch you out and even break you apart at the atomic level. You'd definitely notice that...

In case of accelerating ship, I wonder what would happen in local frame once you hit/get really close to c. You’d get decelerated out of nowhere? Just as if you hit something?

Oh boy, special relativity is another fun one. So here's the thing: there's no "universal speed" that you're moving so you're never any closer to c no longer how long you accelerate for. To accelerate is to change your reference frame and there are no special reference frames.

Which is to say that any physical test you could run inside your ship will give you the same result, always. Accelerate for 13 billion years at any rate and check the the how fast light moves within your ship, the answer is always c.

This is where the name relativity comes in. You have to think in terms of relative speed. Your speed relative to earth will indeed advance closer and closer to c but never reach it. There's a bunch of really wild and crazy implications behind this.

Like that acceleration doesn't change the relative speeds of things uniformly. Keep accelerating at 1 meter per second per second and every second Earth's relative speed changes by less than 1m/s. And look up relativity of simultaneity, another consequence of special relativity. It's fascinating stuff.

[–] INeedMana@lemmy.world 1 points 2 months ago

This is where the name relativity comes in. You have to think in terms of relative speed. Your speed relative to earth will indeed advance closer and closer to c but never reach it. There’s a bunch of really wild and crazy implications behind this.

ah, right. In a ship travelling with c, for someone outside the ship, I turn on the lights and observe the light to travel with c. For that external observer the light from my lamp travels at the same speed as my ship

My mind was already bent! ;)