On Jun 25, 2:36*pm, (Richard Tobin) wrote:
In article ,

Max Demian wrote:
I've just invented a new kind of vacuum cleaner that uses no energy. Just
attach one end of a very long tube to a satellite in geostationary orbit,
with the other end dangling down to Earth. There's a stopper in the bottom
end which you remove to suck up all the dust into space.

A tube to space won't suck air up. *Gravity would hold the air in the
tube down, just like it does the rest of the air.

Yes but only at the bottom. If you remove the stuff below that it
could, feasibly, work in reverse.