Re: [Phys-l] Space Balloon

[Brian Whatcott <betwys1@sbcglobal.net>]

At 10:42 PM 2/19/2007, Herb, you wrote:
> ...
> > On Earth a helium filled balloon rises because of bouyancy.  How
> > would the same helium filled ballon move in a spacecraft (eg space
> shuttle
> > cabin) if it was
> >    a) in orbit around Earth
> >    b) in "deep" space
> ...
> *** a) If the spacecraft is in orbit around the earth, there must be a
> downward force on the spacecraft to keep it in orbit. Remember that the
> space shuttle cabin is usually filled with air at atmospheric pressure to
> keep the astronauts happy. Since the helium filled balloon is lighter
> than the air in the cabin, the air buoyancy force would lift it toward
> the ceiling of the spacecraft.
>
> ...
> Herb Gottlieb from New York City
> (Where helium filled balloons rise toward the ceilings of our subways)

I found it interesting to view some scenes of astronauts "playing"
 in orbit.   Specifically, if they released a bubble of negative buoyancy
 from a drinker,the water blob hung in space.


Brian Whatcott    Altus OK    Eureka!