Article for children written for Exley Publications in 1981:

When I was eleven years old I was taught chemistry for the first time. I learned about substances called chemicals with names like ‘nitrogen’ and ‘sulphur’ and ‘chlorine’, and what happened when you mixed one substance with another.

But I couldn’t see what was interesting or important about them. Nobody told me what these substances were. I decided that they must be things that people dug up out of the ground, and that the reason people dug them up out of the ground was to find out what happened when they were mixed together.

For many years I thought that chemistry was something uninteresting and unimportant. But now I know that everything in the world is made of chemicals – houses, cars, trees and even people; and that chemical reactions are going on all around us all the time. When you breathe, there is a chemical reaction between substances in the air and substances in your lungs. When you burn a piece of paper, it is a chemical reaction that turns it into smoke and ash. But these are complicated reactions, and before you can understand them you have to understand the simpler ones, like those I was taught at school.

If this had been explained to me when I was eleven I am sure that I would have found chemistry a lot more interesting than I did.

I remember a boy once asking a teacher what logarithms were. The reply he received was ‘Never you mind about that.’ I hope that he wasn’t discouraged by this reply, and that he continued to ask questions, because finding out something that you have been wondering about for a long time is one of the plesasures of life.

For the benefit of anyone who doesn’t know, the logarithm of a number is the number of times you have to multiply ten by itself to get to that number. So the logarithm of 10 is 1, the logarithm of 100 is 2, the logarithm of 1000 is 3, and so on. So what’s the logarithm of 50? You might think that it’s 1½, but it’s actually a bit more than 1½ because 50 is not midway bewteen 10 and 100. It’s midway between 0 and 100.

This is an article for people who want to know, but its main purpose is not so much to tell you things you don’t know, but to give you some idea of how nuch there is that you don’t know.

If ever you get a little time to spare, make a list of all the kinds of animal you know. Include anything that moves – birds, fishes, even tiny things like spiders and ants. Have you ever thought that you would like to know the names of all the different kinds of animal there are? There are over a million of them!

Now get a telephone directory and open it anywhere you like. You’ll see a lot of names arranged in columns. Divide one of the columns roughly in half, and then in half again, and count the number of names in a quarter of a column. Multiply this by four and you’ll get the number of names in a column. Multiply this by the number of columns in a page and you’ll get the number of names on a page.

All the pages are numbered, and if you go to the end of the directory and see what the highest number is, you’ll find out how many pages there are. Multiply this by the number of names on a page and you’ll get the number of names in the directory. Don’t bother to work it out exactly. Just say there are about a hundred thousand, or about a quarter of a million. Now divide a million by this number. Supposing the answer is four. This would mean that in four telephone directories there were about a million names.

Now go through the pages of your telephone directory and pretend that all the names there are the names of different kinds of animal. Do you still want to learn them all?   Do you think that you ever will? The fact is that there are so many different kinds of animal, there is no single person in the world who knows the names of all of them!

Lets go back to those chemicals we were talking about earlier on. There is carbon dioxide and ammonia and some others with long names that you’ve never heard of.   How many do you think there are altogether? There are over a million of those too!   It seems to me that if you know the names of ten chemical substances, and know how many there are altogether, you have a better knowledge of chemistry than a person who knows the names of a hundred substances and thinks that that’s all there are.

Have you ever wondered how big the Universe is? In all directions, the Universe is doted with stars, so if I can tell you roughly how far it is from one star to the next, and how many stars there are, you will get some idea of the size of the Universe.

Once I drove taxis in Southampton for about two years, and I worked out that in that time I drove about a hundered thousand miles. If I had started off in Southampton and driven that distance in a straight line I would have got about half-way to the Moon.   So the Moon is a long way away. If you look at the Moon, the light takes 1½ seconds to get to you, which means that light travels very very fast. Yet to get to the earth from the nearest star, light takes about four years. So the nearest star is a very very long way away. The distance between stars varies a bit, but to get from one star to the next the light takes several years.

Now I’ll tell you how many stars there are. There are a thousand or so that you can see without using a telescope, but how many are there that are too faint to see? There are millions of millions of millions of them! It’s no good using a telephone directory to imagine a number as big as this. You would need millions of millions of telephone directories.

The next time you’re on a sandy beach, try counting the number of grains of sand in a bucket-full, or even a teaspoon-full. You’ll find that there are too many to count. Imagine how many grains of sand there must be on all the sea shores of the world. That is roughly how many stars there are in the sky!

The distance of the Moon was worked out by a Greek scientist thousands of years ago, but until 1838 nobody had any idea that the stars were so much farther away than the moon, and it was not until 1924 that people knew how many stars there are or how big the universe is.

In the past few years scientists have worked out how it all began. Before the Universe was created about fifteen thousand million years ago, there was nothing. There wasn’t even any space or time. At first there were only ‘exotic particles’, very tiny things that don’t exist now. About a millionth of a second after creation these particles turned into protons, neutrons and electrons. About a million years later, these protons, neutrons and electrons combined to make up the atoms that everything is made of today.

About five thousand million years after creation the first stars were formed. Five thousand million years after that, the earth and the other planets were formed round the Sun. (The Sun is really one of the stars. It only looks bigger and brighter because it is so much nearer.)

It is always interesting when you find out something that you didn’t know before.   Imagine what it must be like to find out something that nobody knew before!

More new discoveries have been made in the past 150 years or so than in all the rest of history put together, and the same is true about inventions. Things like trains and television sets are so familiar we take them for granted, but before 1825 there were no trains. Cameras were invented in about 1839, and telephones in 1876. The first car was made in 1888, and the first aeroplane in 1903. Radio was invented in 1920 and television in 1936. There are people alive today who can remember when there was no radio or television. You can probably remember yourself when there were no pocket calculators.

If you are at school now, you will probably live for another sixty years. Think how many new things are going to be invented in that time, and how many new discoveries are going to be made.