OK.
Say you build I closed, giant cylinder (ten foot radius) stretching from sea level into space?
It’s built from unobtanium so it won’t break or crush itself under it’s own weight etc
Then you simultaneously create opeings at each end on the cylinder.
Would the atmosphere at the bottom get sucked out into space?
Assuming the cylinder is initially empty, wouldn’t air be sucked in to the bottom of the cylinder and fill it up to the depth of the atmosphere, and then stop?
No. There is no barrier between the atmosphere and space that prevents it from being sucked away. The atmosphere sticks around because the earth’s gravity is strong enough to hold on to it. The funnel would make no difference.
No. Nothing has changed compared to the atmosphere without a giant straw in it. The column of air still weighs the same and has no reason to go anywhere. If God starts sucking on it, though, who knows what would happen…
No it won’t (I believe) for the same reason the atmosphere doesn’t all get sucked out into space without the cylinder - gravity. At every foot along the way, there is equilibrium between the pressure differential and gravity.
Near earth, the gravitational pull will be strongest and the air will be densest, and the pressure will be highest, and towards the top the opposite is true. Gravity offsets the pressure differential.
On preview… what everyone else said.
A good anology, with basically the same assumptions.
Go down to the seashore on a nice calm day. Stick a soda straw down into the water. Does the lower pressure at the top of the straw suck water up the straw?
Actually, it does, ever so slightly. Also visible in a water glass. It’s more prominent with a narrower straw. I forget what this principle is called. It has something to do with surface tension and the inside wall of the straw, I think.
Capillary action. But I couldn’t tell you OTTOMH whether gases exhibit any such tendency; I’d guess not, and even if they did the effect would likely be minuscule.
To say the same thing yet another way, there is already a giant vacuum sucking at the top of Earth’s atmosphere, and there doesn’t get to be yet more of one at the top of this giant funnel just because the funnel is there.
You’re thinking of capillary action, I believe. Which AFAIK applies mostly to liquids in a narrow tube, so you probably wouldn’t see much (or any) in a 10-ft diameter atmospheric straw.
Everyone is giving the steady-state answer. Which, admittedly, is probably what the OP had in mind. But in the case described, the air will initially shoot farther up the cylinder, and some may be lost to space. I just tried putting my finger over the end of a straw, and submerging it about 4-5 inches in a glass of water. The water in the straw shot up about an inch or so above the surface of the water before falling back down.
Exactly.
In all serious, nothing. The top of the straw is already at a vacuum (zero pressure). Even God can’t suck less than nothing.
(This is similar to the Superman example in physics textbooks–i.e. how high can Superman suck a column of water up a straw? Answer: a maximum of 33.7 feet (at one standard atmosphere), because even Superman can only suck down to a vacuum.)
The initial momentum may allow the air to raise farther than the height just outside the cylinder. The air will then all go back down inside if the walls were high enough to contain the air or if it’s to short for that it would spill over falling into the atmosphere around the cylinder. I would be a brief disturbance and equalize.
The top of the atmosphere already leaks atoms of atmospheric gas. With the added momentum, I’d expect more than the steady-state amount of loss of gas.
Does it ever seem that Dopers are all Jewish Rabbis? The word “pilpul” comes to mind.
LOL! You flatter me.
I’ll be signing off soon. See you all tomorrow night! 
The book “Perpetual Motion - The History of an Obsession”, by W.J.G. Ord-Hume, has descriptions of several devices based on the OP’s theory. Unfortunately, none of them ever worked.
I dunno, anything that would basically be equivalent to hanging a sign saying “Hey Galactus - free juice box!” on the planet seems like a bad idea to me.