this post was submitted on 29 Jun 2024
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what really fucks me up is combining this with relativistic effects
like what if you had a rod 100,000 km long and you started rotating it around one end. does the other end exceed the speed of light? I know the answer has to be no, which means you're going to get all sorts of weird relativistic effects along the rod
I have heard this thought experiment before. I think the answer is that there is no perfectly rigid rod. The nudge at one end travels down the rod as a pressure wave at the speed of sound of the material, which will be much slower than the speed of light. And in reality, centripetal force would tear apart a rod well before its tips rotate at light speed.
If you put clocks on different parts of the rod, they'd get out of sync. It's weird.
The force required to accelerate the outer part above light speed exceeds infinity
give me a lever big enough and i will turn the world