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Here's the setup: You have a space station orbiting Earth. On this space station is an anti-gravity device powerful enough to lift a small ship on Earth up through the atmosphere and into the space station (or next to it, anyway). Disregard for the moment how such a device works or came to be.

The problem with this highly convenient technology is that it essentially creates a column of reverse gravity (gravity going against Earth's natural gravity - that is, up) from itself to the surface of the Earth, wherever it happens to be pointing. This means that anything in that column of reverse gravity is going to be sucked off of Earth and into the space station, including the ship it's targeting, any unfortunate individuals out for a scenic flight, and all the intervening air.

It's the air I'm concerned with. What would happen if a column of air was abruptly sucked into outer space? Since the space station is close enough to be orbiting Earth, I would assume the gases making up the air would eventually return to the atmosphere, but what would the effects be in the meantime?

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  • $\begingroup$ Are you mainly concerned with what happens to the column of air on its way away from Earth, or are you concerned with what happens on the ground as a result of that column of air being removed? Or both? $\endgroup$ – a CVn Nov 9 '15 at 19:05
  • $\begingroup$ Both. All effects, everywhere. $\endgroup$ – Thomas Myron Nov 9 '15 at 19:13
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Almost all of the air would escape the column on the way up.

As your gravity beam lifts denser/higher pressure air up, it will expand to match the pressure outside the column, so the rising air molecules move out of the column, where they will disperse their upward speed.

The molecules in the very top layer of the atmosphere might experience enough upward acceleration in the beam to escape the earth entirely, but since the density is so low, there just won't be a significant number of them in your ship-sized column, compared to the usual number that escape over the entire atmosphere's upper edge.

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Not much would happen. Space stations orbit Earth at an altitude between 200 and 250 miles. At that altitude, Earth's gravity is about 90% of what it is on the planet's surface. If you lifted a ship and a column of air, the effects would most likely be negligible. Once the reverse gravity was turned off, the air would expand massively in the vacuum of space and simply fall back into Earth's atmosphere. I don't believe you could lift air with a large enough volume and speed to cause a measurable weather change.

You have an interesting idea, but there is I think there is flaw in the logic. The International Space Station is traveling at a speed of 16920 MPH. The Earth only spins at 1000 MPH. A ship on Earth would have to be traveling at the same speed of the ISS to stay within the column of reverse gravity. A rocket needs to attain a speed of 17,600 miles per hour to break Earth's gravity. If the ship can move that fast to stay in the column, there is no need for the reverse gravity of your space station, as the ship can break Earth's gravity and travel to the station on its own in under a minute.

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  • $\begingroup$ The space station could be GEO, meaning much higher up than today's stations but in synch with earths rotation. The question does not specify the orbit actually. $\endgroup$ – Ghanima Nov 7 '15 at 10:03
  • $\begingroup$ That had actually occurred to me. Could a space station still have a fairly close orbit and travel at the rotational speed of the Earth? $\endgroup$ – Thomas Myron Nov 7 '15 at 20:12
  • $\begingroup$ It could, but only under constant thrust, for example if it "reversed polarity" and pushed itself away from the planet whenever there was no ship ascending. This device could be on the planet surface too then, just pushing ships up. $\endgroup$ – Cyrus Nov 8 '15 at 8:11
  • $\begingroup$ @Cyrus How high would the station need to be to maintain its altitude without additional thrust? $\endgroup$ – Thomas Myron Nov 9 '15 at 19:15
  • $\begingroup$ Directly from wikipedia: A geostationary orbit is a circular orbit 35,786 kilometres (22,236 mi) above the Earth's equator and following the direction of the Earth's rotation. $\endgroup$ – Cyrus Nov 9 '15 at 19:47

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