Now, why is that? Because at warmer temperatures, the molecules have more energy, and therefore, they move faster and move more rapidly.
Now, let’s just carry on, on to my favorite topic, which is fire. This flame here represents — This flame here represents one of the greatest traditions of the human race, and that is, of course, our ability to make fire.
We know that in East Africa, where the first ancient civilizations were 100,000 years ago, people were able to make a fire and sustain a flame. I’m now going to just show you how 10,000 years ago, for thousands of years, flames burned like this.
This is a piece of cotton wool, and you will notice, it’s a dreadfully boring flame. It just burns like – Why is that? Well, because the cotton wool is surrounded by air. Air only contains 20 percent oxygen. It was only realized that air is a mixture of gases about 300 years ago, and we’ve been on this planet for a hundred thousand.
And once chemists had discovered that oxygen is the vital component of air that makes things burn better, they started either combining fuels with oxygen, or mixing them with oxygen. And here I’ve got a piece of cotton which has been chemically combined with oxygen.
Please watch how differently this burns. And we put it into here. And you notice – it’s blown the flame out. I knew it would blow the flame out. That’s adding an extra three seconds on to my talk. Never mind, we shall quickly – I was ready; I had my matches.
Now, what I wanted to show you, I’ve just shown you the world’s first high explosive, nitrocellulose, or guncotton. I’d love to do an explosion with it, but I can’t; we don’t have the time. I’m going to show you a propulsion.
This here is a mortar. It’s a type of device which is used for propelling fireworks high into the sky. I’m not going to prepare fireworks, I’m going to propel ping pong balls. Sorry, I’ve got four ping pong balls in my pocket here. I have a guncotton cage here – dropping it to the bottom – sorry, has it gone to the bottom? I don’t know. Too bad.
I’m going to force it to the bottom. I’m sorry. I’m struggling a bit against the odds and against time. Let me just – there we are. I think it’s gone to the bottom. If it hasn’t, too bad. We’re going to shove a fuse in there, and that will hopefully, when this goes off, we’ll see it going up to the – we’ll watch the ping pong balls fly out, if they managed to reach the bottom. If they didn’t, that’s too bad; then, we won’t see anything.
But there goes our fuse, hopefully – come on, catch fire; time’s running short. Theory, theory. This is a very bad piece of fuse. Sorry. I’m going to have to put my fingers on and lift. There we go.
Now, on to the final things here. Here we have – there we are. I don’t know whether – did anything happen? Yes, they went up. Now, here we have – sorry – very quickly, we have here a balloon filled with hydrogen – caused a complete sensation among scientists, the lightest gas in the universe – going off. That’s pure hydrogen. This is thunder air, aria tonante, a mixture of hydrogen and oxygen. That makes that much louder.
Now, for my very fine work, I have here a mixture of hydrogen and oxygen. I have a fuse which I’m going to make here, and this will be my final experiment. We’re going to have a thunder and lightning effect here. We’re going to have thunder – sorry, everything is going mad. Let’s get rid of this balloon; it’s getting in my way. Now, here we are.
I’m going to make up some flash powder, fuse powder. This is going to be – so, to summarize, what have I been talking about? Chemistry.
What have I been selling to you? Chemistry, in simple and direct language, chemistry for all.
So here we go. Fingers crossed. (Bang) And there it is! So thank you very much. Thank you very much indeed. I wish you all the very best. Thank you for your kind attention. Thank you very much indeed. Thank you so much. I did 15 minutes on the dot. We’re still in one piece. I wish you the very, very best. Very, very many thanks indeed.