this post was submitted on 11 Feb 2025
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It can look dumb, but I always had this question as a kid, what physical principles would prevent this?

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[โ€“] 4z01235@lemmy.world 2 points 3 days ago* (last edited 3 days ago) (1 children)

https://www.quora.com/What-if-you-walk-forward-on-a-ship-moving-at-light-speed#%3A%7E%3Atext=You+would+experience+nothing.%2Cof+travel+wouldn%27t+exist.

Because of relativistic effects, from your point of view on the train you would just walk forward. But you would notice a strange effect while the trains were accelerating: ~~your atomically synchronized wristwatch~~ the clock you can see out the window has slowed down and stopped counting time. So it seems that your journey to the front of the train takes no time at all.

From someone standing on the side of the tracks catching a glimpse of you and the train as you whizz by, the front of the train is moving at light speed. You're at the back of the train completely frozen still, unable to move forward because the front of the train is moving away at light speed.

Weird things happen when you're talking about the limits of physical reality.

[โ€“] tetris11@lemmy.ml 4 points 3 days ago* (last edited 3 days ago) (1 children)

your atomically synchronized wristwatch has slowed down and stopped counting time.

Wait, surely time would move at a normal speed within your own reference frame. The act of you walking to the front of the inner-most train you are in would be a normal occurence to you, but if you looked out of the window you would see a completely frozen scene.

Only once you measure time afterwards with an observer would you notice the gaping time difference.

[โ€“] 4z01235@lemmy.world 3 points 3 days ago

You are correct, I should have said there was an atomic clock out the window that the walker looked out at.