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Alis451 t1_j0ghvj9 wrote

Reply to comment by alukyane in Does rotation break relativity? by starfyredragon

>how free fall could be distinguished from 0 gravity.

The Space station is at 0g, but they aren't far enough outside of the Earth's Gravity well to be at Zero Gravity, because if it were it would start sticking itself, Earth's Gravity supersedes your own in relation to other nearby objects. So YES, there is a VAST difference between 0g and Zero Gravity. The space station is in a constant freefall and needs to continuously adjust.

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Aescorvo t1_j0gs39z wrote

Actually, let me amend what I said. Without looking out the window (metaphorically) you couldn’t tell. However, if you had a clock on board, and and an identical clock far enough away that it was effectively in zero gravity, AND you could view it through a telescope each revolution, you would (eventually) see that the clock runs faster than yours. That would at least tell you that it was experiencing lower gravity than you were.

This is akin to one of the effects that we have to account for with GPS satellites. Putting a clock in orbit (with a big enough display) would let us see the discrepancy compared to an identical clock on the surface, deeper in the gravity well.

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alukyane t1_j0h92dr wrote

We then seem to agree that the top-level claim above about acceleration is wrong: you can't actually tell whether you're in an inertial or accelerating frame, if the acceleration is the same for all observable objects. Right?

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