Casting around for a book to read at the weekend I came across a book I must have picked up at a fete but I do not remember buying it. It is called ‘Science, Numbers and I’ and it is written by Isaac Asimov. It is not one of his science fiction books but a collection of, to use Mr. Asimov’s own phrase, ‘speculative essays on the known and the unknown.’
I reached Chapter 5, ‘A Matter of Scale’ where he starts by referring to representations of the Solar system designed to give a feel for the relative distances involved. You know the sort of thing, imagine the sun is a football then the earth will be a pea thirty yards away. Well, he does just that but he starts with the sun as a one foot diameter ball in the middle of Central Park, New York. Then he lists all the planets giving their diameter and distance from the sun so that Earth turns out to be 0.110 inches in diameter and positioned 107 feet away from the sun. All very interesting but I have read all this before. The bit I didn’t know, though, was where the closest star, Proxima Centauri, would be on this scale. Before you read on hazard a guess to how far away this representation of the start will be from our one foot diameter sun. It transpires that it will be 5,500 miles away or, with Central Park as the starting point, in Jerusalem. Isn’t that just amazing?