Re: Fish tank in orbit?

[Leigh Palmer <palmer@SFU.CA>]

At 10:35 AM -0700 10/11/00, I wrote:

> The tank itself is more interesting. If air space (or ullage)
> exists in the tank, and if the walls of the tank are wet by the
> water, then the system would be in its lowest free energy state
> with a minimum air-water interface area. In equilibrium the air
> would form a spherical bubble within the tank, geometry
> permitting. The fish, swimming frantically, should occasionally
> swim through the bubble

On further reflection I realize that a fish swimming into a
sufficiently large bubble would, indeed, make it through the
bubble. If the fish were to *coast* into the bubble, however, it
would (by conservation of momentum) come to rest just as it
reached a position fully inside the air space! The problem is
even more interesting in this case.

Leigh