 Hi, I'm Ethan Allen. I'm a host on likeable science on Think Tech Hawaii. And I'm here to share a little interesting science with you today. Some of you may have seen this demonstration before, but you probably haven't thought about what it really means. The demonstration is very simple. You take a balloon, you blow it up. Standard party balloon, standard source of flame. You could use a candle for this, too. You lower the balloon onto the thing and pop. The balloon pops. Nothing surprising about that. You take the same kind of balloon and you put some water in it. This is about half filled with water. Lower it onto the flame and notice what happens. The flame just sits there burning away onto the balloon, onto the skin of the balloon, onto the skin of the balloon, as long as you want to leave it there. And the balloon does not pop. So why is this? Why is this balloon not popping? What's going on here? You would think, I mean, this has been on that balloon now a lot longer than the other one was. And the balloon is not popped. You can see from the bottom of the balloon, it's got a lot of black soot on it from the flame. It hasn't popped because the skin of the balloon has never heated up enough to melt and cause the balloon to burst. The skin of the balloon has never heated up because it is backed by water. Water has tremendous heat capacity. It picks up heat and moves it away very effectively, very efficiently. Water has this huge heat capacity, more so than almost any other substance on Earth. And it's this property that sort of highlights the implications of this demonstration for our planet. If you think about the flame here as the sun and the water in the balloon as the oceans, you get some sense about this. That is, every day, particularly here in the tropics, the sun beats down on our oceans, warming them slightly. Warming them slightly a bit, but they keep just moving heat away, moving heat away from where the sun is shining most intensely on them, moving heat away, moving heat up towards the poles and then gradually releasing that heat into the air, onto the land around it. And it is that process that spreads heat very effectively over much of the surface of the Earth. So the sun's heat is not just concentrated in the tropics where it really falls, but is instead spread over much of the surface of the Earth. If it weren't for this amazing heat capacity of water, there would be a very narrow band of intense tropical heat, a very narrow band of temperate zone, and a large part of the Earth covered permanently in ice. But because of water's inordinate heat capacity, much, much, much more of the Earth is actually habitable and not frozen. That's all there is. It's a cute little demonstration, but it tells us something very profound about the way our whole planet works. Hope you enjoyed it. Bye-bye.