Space is vacuum right? Why can’t we just put a chimney through the atmosphere and suck stuff like greenhouse gasses into space?
In: Physics
Gravity pulls gases down, including the gas atoms in the chimney. Even If you built a chimney 50 miles tall, it would exhibit the same altitude dependent pressure as outside.
Because gravity is stronger then the pressure that makes things go into a vaccum. Making a chimney would be useless, because those green house gasses are in the atmoshpere- the sky.
While they are technically heavier then air (at least CO2 is) if air doesnt go away at all it doesnt matter.
Although, the reason GHGs are bad is that they block heat radiating to space. So in essence, we could trap a lot of heat and make it radiate somehow into space, making a sort of heat-chimney.
You realize the entire atmosphere is exposed to space. If the chimney would have air flow through it than the atmosphere would already have exploded away from the earth. The gravity of the earth pulls the air against the surface.
There’s a vsauce video that explains what you’re looking for pretty well called Space Straw.
Gravity, and it’s worse than other comments describe. Let’s say you build your super-strong chimney, and pump greenhouse gasses into it to shoot them into space. They will shoot out into the vacuum of space, and then drift right back down into the top of the atmosphere, just like Jeff Bezos’ rocket – what goes up must come down†.
† Yes, it’s more complicated than that, but this is ELI5.
There is no central concentrated pool of greenhouse gases. There is just the atmosphere, a wild jumble of all kinds of different gases, impossible to separate on any but the smallest of scales. Even if it weren’t, any one of those gases has better applications than to irretrievably get rid of them.
There is no way contemporary engineering could facilitate the construction of some kind of pump/acceleration/tower/space elevator system to do such a thing. And if it could, the infinite applications of this kind of magical future technology would be otherwise employed.
Space is a vast vacuum. Gas moves freely and does not stay bound to 0 pressure. Its kinda like water in space. It moves freely until theres an object, then it sticks on. So we would basically be filling a sun sized bottle with only drops of water at a time and expecting it to fill.
The atmosphere is open at the top now. If greenhouse gasses were going to flow out into space, they would already be doing that.
Also, building a tube that goes to space would require incredibly strong materials to keep it from being torn apart by its own weight. You’re effectively asking for a space elevator. It’s been suggested before but we don’t have anything strong enough to build it. Carbon nanotubes might be strong enough eventually, but that’s still something that we’re working on.
https://en.m.wikipedia.org/wiki/Space_elevator
A vacuum doesn’t “suck” things. Only the pressure differential *pushes* things into the vaccum when you generate one on the ground (e.g. with a pump).
In your scenario, that push is exactly counteracted by gravity.
Maybe an equivalent question is “why doesn’t the vacuum of space suck away our atmosphere?” The answer is that vacuums don’t “suck”, really, there’s just a pressure difference. Straws work because you lower the pressure in the straw, and the weight of the atmosphere pushes the water up into the straw. So why doesn’t the atmosphere vanish? Because gravity holds it down to Earth’s surface, and there’s no corresponding outside “pressure” to lift it into space.
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