Re: Fish tank in orbit?

[Leigh Palmer <palmer@SFU.CA>]

At 8:36 AM -0700 10/11/00, John Mallinckrodt wrote:
> On Wed, 11 Oct 2000, Bob Sciamanda wrote:
>
> > Without gravity, there is no buoyancy (nor is any needed).
>
> I guess it depends on what you mean by "needed."  If I were
> enclosed in a big blob of water in zero g, I'd sorely miss the
> gravity that would, in turn, give me net buoyancy (if my lungs
> were sufficiently full) and that would, again in turn, send me
> in the direction of air, if there were any to be found.

Clearly the center of buoyancy in a fish is dorsal to its center
of mass. Gravity certainly matters to a fish. Resourcefulness and
rapid adaptability are not notable piscine attributes, so I guess
I would expect a dumb fish to be discombobulated in zero gee.

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, an interesting sight to contemplate, and
one unlikely to be antidiscombobulating (or, simply, combobulating)?

> ;-)  <-- (for Leigh)

Thanks, John, for an excellent example of a gratuitous emoticon.

Leigh