From: utzoo!decvax!harpo!floyd!rjs
Newsgroups: net.physics
Title: A different ice question
Article-I.D.: floyd.1434
Posted: Wed Apr 13 10:20:40 1983
Received: Fri Apr 15 02:08:27 1983

At various times in my life, I have been told by people, in a matter of
fact way, that warm water will freeze in an ice cube tray (in the freezer)
faster than cold water.  They always claim that experiments have been
done which show this (but of course never supply references).  Normally
I just toss this off as being an old wive's tale, however, recently a
person with a Chemistry degree also made this claim, making vague references
to convection currents in the water.

If you ignore convection currents, the warm water would take some time x
to cool to the temperature of cold water, and then time y to freeze, but
cold to start with water would just take time y to freeze.  It also seems
to me that with convection currents doing their thing, the time to go from
warm to cold will still be much larger than the time it takes friction to
drag those currents to a halt once cold water temp. has been reached.

What gives?  Is there really evidence for such a counterintuitive
phenomenon, or am I the victim of a massive practical joke?

	Robert Snyder
	floyd!rjs