"Zero gravity" has nothing to do with how high you go - gravity drops off by the inverse square of the distance from the center of the Earth, so being at an altitude of 350 km, roughly the same as the International Space Station, means that gravity is still at about 90% of the force we feel here on the surface. It's what keeps the ISS and satellites in orbit, after all, rather than flying off into deep space.
Zero g has to do with acceleration _ for example, if an elevator's cable is cut and it accelerates towards the ground, all objects inside the lift are accelerating at the same rate as the lift itself and thus are not pressed down against the lift floor, and are free to float around. Briefly, before the sickening thud. Objects in orbit are in "free fall" - that is, they are falling towards the ground, but their sideways motion means they always miss, and are thus permanently falling, thus the contents don't feel accelerated and are all floaty. If you were standing on a 350km tall tower, and thus stationary relative to the ground rather than free falling in orbit around it, you would feel that 90% of regular gravity I mentioned.
If you want to experience zero g in the near term, and at significantly lower cost than going into space, you can buy tickets to ride the Vomit Comet - the aircraft used to train astronauts. It moves in parabolic arcs, so that on the downwards dive passengers get up to 30 seconds of weightlessness before the plane has to pull up to avoid yet another sickening thud.
Some people find free fall rather disconcerting, as the primitive monkey brain keeps telling them they've fallen out of the tree.
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Zero g has to do with acceleration _ for example, if an elevator's cable is cut and it accelerates towards the ground, all objects inside the lift are accelerating at the same rate as the lift itself and thus are not pressed down against the lift floor, and are free to float around. Briefly, before the sickening thud. Objects in orbit are in "free fall" - that is, they are falling towards the ground, but their sideways motion means they always miss, and are thus permanently falling, thus the contents don't feel accelerated and are all floaty. If you were standing on a 350km tall tower, and thus stationary relative to the ground rather than free falling in orbit around it, you would feel that 90% of regular gravity I mentioned.
If you want to experience zero g in the near term, and at significantly lower cost than going into space, you can buy tickets to ride the Vomit Comet - the aircraft used to train astronauts. It moves in parabolic arcs, so that on the downwards dive passengers get up to 30 seconds of weightlessness before the plane has to pull up to avoid yet another sickening thud.
Some people find free fall rather disconcerting, as the primitive monkey brain keeps telling them they've fallen out of the tree.
Sorry about the geekspasm.