 Hi, I'm Ethan Allen here on Think Tech Hawaii. I'm the host of likeable science, and today we're going to do a little bit different kind of activity. We're going to actually show some real science. You may have seen this activity before. It's a very simple one, which is part of its appeal, but it tells us something very profound about the world we live in. So here's a balloon filled with just air. I've just blown this up. And here's a source of flame. Now when I bring the balloon down onto the flame, almost as soon as it touches the flame, even in a few seconds the balloon pops, right? Now I take a balloon, just same kind of balloon, but this has water in it. It's about half filled with water. I bring it down onto the flame, and notice it just sits here. The flame burns against the skin of the balloon, but nothing happens. The balloon does not pop, it just sits here. I can sit here, and I can do this for quite a long while, and you can see the bottom of the balloon actually blackens up a bit, but the balloon does not pop. So why is this? Why does this happen? What's going on here? Well, the balloon pops because its skin melts when it's heated up by the flame. When there's water in the balloon, the water actually moves the heat away from the skin of the balloon quickly, very quickly, very efficiently. The skin of the balloon never heats up to its melting point, and therefore the balloon never pops. This speaks to the large so-called heat capacity of water, its ability to absorb a lot of heat, move it around very quickly and efficiently. This phenomenon, this heat capacity of water, is really important on a global scale because it is water that moves heat around on Earth. If it weren't for water, our Earth would be a very, very different place than it is. The sun, if you think of this flame as the sun and the water in the balloon as the ocean, the sun heats the equatorial waters very well, just pounding energy into them, and this water heats up and gradually moves northward and southward towards the poles, gradually dissipating heat as it goes, warming the air above it, warming the land around it. That's why so much of the Earth is actually quite temperate. The tropics, particularly out in the ocean regions, are not overly hot, and meanwhile, well up into the polar regions, at least for part of the year, the area stays quite temperate and is quite livable. If it weren't for this, if it weren't for the property of water to absorb heat and move it around, the Earth would have just a very narrow band of intensely hot area and a large portion of the Earth would be covered by ice caps and be completely frozen. There would be a very small temperate zone where life could exist, but because of this marvelous property of water, this great heat capacity, our Earth is this wonderful, sustaining temperate zone basically over virtually the whole Earth that supports life and makes life possible. That's it. Simple but profound. Thank you so much.