ICR does talk about that (or has in the past at any rate), but frankly it's only one of numerous factors that make Earth uniquely suited to life as we know it (carbon-chain-based blah blah blah). Earth's atmosphere is rare, for instance, in being adequate to support photosynthesis and respiration but transparent enough to allow enough light to penetrate to support photosynthesis, and to allow the stars to be seen (which is not so important for life but crucial for civilization). Our atmosphere also is rare in having enough diatomic oxygen (a powerful oxidizer) to support respiration but not quite enough to be really dangerous chemically (a few percentage points more would be quite hazardous). Once you start down that line of reasoning, the list becomes endless. The sun is just right. The moon is just right. Earth's gravity is just right. The ratios of the various elements is just right, which astronomers believe is not so true in most of the galaxy (though objectively we don't really know that for sure). The distance from the Sun to the Earth is absolutely perfect. The *amount* of liquid water is enough to create large oceans but not so much as to cover the whole surface. Et cetera, ad infinitum, ad nauseam.

Of course you can interpret those data in various ways. You can say, "Well, duh, it was designed that way", or you can say, "It's perfect for us because we evolved and adapted under those conditions". Your conclusions depend not so much on the data as on the implicit assumptions you make going in. In other words, people believe what they want to believe.

http://www.lsbu.ac.uk/water/anmlies.html

...which played a big role in the development of life on this planet. But we can't, of course, say for sure that the planet would be lifeless if water didn't behave in the way that it does. Perhaps land-based life would have developed by itself, perhaps water-based life would have developed when and where liquid water could still be found - deep oceans (climate permitting), underground water pockets, et cetera.

I think it's fair to say, however, that if the only life on a planet exists in water pockets deep underground, that life's probably not going to evolve sentience.

The basic idea is that, since water has its highest density (at ST) around 277 K, as you cool a large body of water the cold stuff will sink. As soon as the whole thing (baring thermal layers, of course) reaches 277K, the colder water will no longer sink. That means that it will freeze at the top first, and provide a not-insignificant insulation to the layers of liquid water beneath it. Thus, rather than the whole body of water freezing solid by the coldest stuffs continually sinking, you end up with just a crust freezing, and the rest staying a toasty 277K!

Hope that explains it somewhat...

That's interesting. Can you elaborate on that, or point me towards further reading?

http://en.wikipedia.org/wiki/Hydronium
http://en.wikipedia.org/wiki/Hydroxyl