While I'm at it I might as well ask your help on another question that has been bugging me for a while. Let's hypothesize a huge "straw" a hundred metres or more in diameter. One end of this straw is at sea level. The other end is at 10,000 metres in altitude. It's obvious that the air pressure inside the straw would equalize, but if (again hypothetically) it could be "started" somehow, would there be a siphon effect which would push the sea level atmosphere up the straw to the stratosphere and would this effect be self sustaining? Thanks again in advance for any assistance.