I was thrown in at the deep end of popularization by having to give the Royal Institution Christmas Lectures [5] in 1978. The Christmas Lectures were founded by Michael Faraday over 150 years ago in order to give schoolchildren an opportunity to see some science. They have been given every Christmas since then (except during the war). They are usually devoted to physics, chemistry, biology or medicine, and mine were the only time they have ever been given on mathematics. There are six one-hour lectures to an audience of Young Persons at the Royal Institution between the ages of 10 and 17, and nowadays they are also broadcast on TV each day between Christmas and New Year, or thereabouts. So it was a daunting task: they had to be accessible not only to schoolchildren but also to the general TV public, and subject to the direct scrutiny of one's colleagues and other professionals.

What kind of mathematics could one possible give on TV to such an audience? It took me a year to select the topics, and about six months to write the lectures, with a month of panic at the end preparing all the demonstrations and illustrations. Fortunately I had the time because I happened to be in the middle of a 5-year SERC Senior Research Fellowship.