[Physics] How you feel in outer space vs. orbit

centrifugal forcecentripetal-forceequivalence-principlenewtonian-gravitynewtonian-mechanics

I understand that when someone is in low earth orbit, the "pull" of their inertia is equal to the pull of gravity. However, the force of gravity is still acting on them. However, if they are in outer space there the pull in any direction is miniscule, they should feel different that the way they feel in orbit, because you feel forces on your body and in outer space there is no net force while in orbit there is. Am I correct?

Best Answer

They should feel the same. You only feel forces in orbit if there is something causing sensations, and nothing does in either case. Even on earth, you don't feel the "force" of gravity; you feel the force of the floor pushing you up so that you don't start falling under gravity's influence. In orbit, there is no floor, so you don't feel gravity.

You might imagine a force pushing on your spacesuit which then pushes against you. But in orbit, the force on your spacesuit causes an acceleration of the spacesuit that's exactly the acceleration that your body experiences, so there will be no relative difference in the motion of your body and your spacesuit, so you won't feel anything.

Or you might imagine your left arm feeling a different force than your right, and so feeling pulled apart. But the accelerations they experience in orbit will be the same, so their relative positions won't change, and you won't feel any difference.

(Technically, there might be minuscule differences referred to as tidal forces. These should be measurable by extremely sensitive instruments, but not by humans orbiting anything humans are likely to orbit any time soon.)

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