> Well, I forgot emphasize that water is a very anomalous substance -- it has discontinuous volume changes during its cooling, causing its solid form to be lighter than its liquid form. The reason it does this is due to its high affinity for aligning hydrogen and oxygen atoms into very regular hydrogen-bonding pairs. These regular 'H-bonded' molecules take on an ice-crystal lattice structure that's similar to diamond, and the entire structure spreads out over a greater space (volume) for a given amount of mass. In other words, ice is bigger but less dense. If ice does not have room for expansion when it is created, it may rupture its container.

I just thought of something: If you put a container of water in a freezer, it will crystallize from the outside and inwards, causing the core to freeze last. But since water expands when it freezes, this must seriously mess up the crystalline structure, since the expanding liquid core will be "shut in" by the surrounding ice. How would it look if you were able to freeze it from the center and outwards? Would it be much different?

Trav"inquisitive mind"holt.