~ jan wrote:

On Fri, 23 Nov 2007 12:35:32 CST, Derek Broughton
wrote:


....stirring make it freeze immediately....

That goes against the principal that moving water doesn't freeze as fast
as still water, doesn't it? ~ jan

Still water will likely locally reach freezing point sooner than moving
water, but I was talking about supercooling, which is what "hyperchilling"
sounds like. If you have pure water (the purer the better) in a glass in
the freezer, you can probably get it to a few degrees below freezing - as
soon as you disturb it, or drop in a single grain of salt it will freeze
solid. Another simple example is to put a bottle of beer in a freezer.
You can take it out, see that it's still liquid, but the moment you pop the
cap it will freeze - it starts to crystallize around the released bubbles
of CO2.

Also, note that the common trick of preventing water from freezing in pipes
by leaving a faucet dripping has nothing to do with moving water not
freezing as fast as still water. That just involves bringing water from a
supply system at 10C fast enough that it never has time to freeze.

I just don't buy the idea that a goldfish can be "hyperchilled". Either
that means the water was sub-freezing - which shouldn't be possible in a
pond - or it means that some point above freezing is too cold for them, and
I have ample evidence that they survive well down to 0C (though I have,
from time to time, found little frozen bodies embedded in the ice - they
don't take that well!).
--
derek