I’m going to go out on a limb and make what you may think is an outrageous statement: Water is the most interesting substance in the world. Some of you may immediately respond, “Oh, yeah! What about beer?” (Or wine, or Sidecars, Negronis, or Sazeracs — or whatever your drink of choice is.) Without water, we wouldn’t have those drinks.
But what else makes water so interesting? Well, let me name a few things. The water molecule is polar, which makes for lots of interesting properties.
When liquid water becomes a solid, it does the opposite of most other materials making that phase change: It becomes larger! And did you know that liquid water reaches its highest density at 4°C (39°F), not 0°C (32°F)? That’s right. It starts expanding even before it freezes.
That fascinating property ensures that fish don’t freeze into a block of ice in winter — because as the air above chills the water in a lake or pond, the water becomes more dense and sinks, until it reaches 4°C. As the temperature goes below 4°C, the water becomes less dense and sits on top of the more dense water. And that’s why lakes freeze from the top down instead of the bottom up, sparing all the fish in the process.
But you’re here to find out…