PFE018: Water

I'm pretty fond of water. I drink quite a bit [of water] every day. Why this affinity? Perhaps it's because I am, in most senses, water.

Or perhaps it's because water is not only super common on earth, but also has some really unique properties.

This post is a little long, but it's been awhile and seriously guys, I love water.

Water, as we all know, freezes at 32^oF and evaporates at 212^oF (Fahrenheit because I only understand Celsius abstractly anyways). This means that water is found in solid, liquid, and gas forms on earth all the time which is super convenient (because each is helpful in different ways).

Also, because of its shape (the fact that two hydrogen atoms are attached to an oxygen atom, but aren't directly opposite from each other

as you might expect. While the effects of this are not immediately obvious, it turns out that it means that water is great at storing heat. This is both a blessing and a curse in the sense that heat can be transferred really easily by water which is great because there's so much of it and so it is great for cooling. On the other hand, when we try to heat up water for our pools/showers, it is very difficult to do so.

Those were some of the technical or precise things that make water so interesting. But let's look at some practical things that are a little bit more difficult to model by conventional means.

We all know that water evaporates at 212^oF, but if we think for a second we can realize that this isn't actually true. Of course, when we boil water, the water at the bottom of the pot hits 212^oF. But this isn't the only way water evaporates, because water "dries up" all the time even though it never hits 212^oF outside. So where's the mix-up? Any official explanation in a physics or chemistry text book will start talking about relative vapor pressures which always seemed unnecessarily confusing to me. The interesting phenomenon that is occurring here has to do with the aggregate behavior of water. When we say that water is at 73^oF, that is to say that the water has an average temperature of 73^oF, but some water molecules may have a lower temperature and others a higher. And sometimes, when a molecule has a really high temperature and is near the surface, it will fly off into the air and evaporate. The rates at which these happen depend on a bunch of things including the temperatures of the water and the air, the humidity of the air, what kind of gunk is mixed in with the water, and probably the day of the week. But what we do know is that it happens.

Perhaps more interesting that water evaporating below it's supposed to, is looking at the freezing point. Although president Leebron seems to think that water turns to ice at 32^oF people from the north (such as, you know, me) know that this isn't really the case. That is, in practice, it requires a colder temperature than 32^oF. See, when water freezes into ice it forms these wacky crystals.

This stuff is crazy.

All on its own! But when it comes to freezing water, this doesn't happen easily. So any movement in the water and it basically loses all progress and has to start over. This structure is what gives rise to snowflakes and I don't even need to tell you beautiful they are.

Ok, maybe I do if you didn't grow up in the North.

If you're interested in some do-it-yourself science involving explosions, you can easily separate water into hydrogen gas and oxygen gas. While this experiment is very easy to do, it is also very easy to get carried away so I won't sort out the details here, but you can find them easily on the World Wide Web but please don't blow yourself up.

That's water.