I love ice, when I was in Antarctica many decades ago, I got to see a lot of ice. And the one thing that impressed me -because I love to talk about ice - is that it has a color.

Form follows finances instead of function.

Amorphous forms [of ice], for example, are found naturally on comets, on asteroids, and the crystalline forms are found on Earth or at least could be made on Earth with enough pressure. Nothing else does this.

The principal reason it transforms is that water is a collection of molecules, H2O, every child learns that.And that bond has the property that as the bonds get stronger when you cool water, the ice expands.

H2O it's a complicated, three-dimensional, charged object. And one can pack these things in many different ways, a little like playing the child's game of jacks, where those complicated little objects can be thrown together in all different ways.

I think the most remarkable thing about ice, in my opinion at least, is that it occurs in many, many, many different forms. Most solids occur in typically one or maybe two or three different forms, and ice has approximately 15 different crystal forms, as well as two forms that are called amorphous, which means without any shape at all.

There's something very magical about water and what happens to it when it freezes. I don't think there's anything else in the world, perhaps in our universe, that is quite like ice.