Originally posted by: Darkcirc
If you remember from chemistry H2O has the rather odd property of 'fluffing' (technical word, I swear) up when hotter or colder than 'normal' (as in become less dense). The fact that is takes more extreme temperatures in one direction than to other to equal the change in density would allow for the 'heavy' ice water. This is an example, don't try it please. if you fill a glass container with room temperature water and place it in the freezer either the top will burst or the glass will shatter when it freezes. If you fill that same container with boiling water (right on the edge of the phase change[to a gas]) and place it in the freezer, with oven mitts of course) you stand a considerably better chance that the glass and/or top will NOT break when reaching the other end of the phase change (to a solid). The reason? The hot water is less dense than the cold, so as it approches the temp of the room temp water it contracts, and then expands, presumeably to the volume it had when it was hot, plus or minus a little when it freezes. And that my friends is shy water sounds different.

dc