## Continental drift

The theory of continental drift is now a well-established part of orthodox explanations of how the Earth got to look how it does. Not so when I was growing up in the early 1960s. From a very early age I was fascinated by my father’s globe, and the amazing amount of information contained on a piece of paper of area $4\pi r^2$, with r somewhere in the region of 15 cm. My best birthday present ever was an atlas my grandmother gave me when I was 5, and I loved doing jigsaw puzzles, especially when the picture was a map. With this background, it is impossible not to notice that the East Coast of South America fits into to the West Coast of Africa like a hand in a glove. When I was told, it’s just a coincidence, it doesn’t mean anything, I realised for the first time that grown-ups don’t know everything. I knew deep inside me that it could not be a coincidence.

Fast forward half a century. I approach particle physics as a 55-year-old child, wanting to learn everything. But I am still a child, I want to know the truth, I am not interested in answers that say it’s too hard for you to understand, because it is *not* too hard for me to understand. Continental drift is easy for a child to understand. Things that grown-ups say are fixed and have always been that way, children can understand might not always have been that way. I looked at the masses of the elementary particles the way I looked at the coast of South America, and I looked at the Solar System the way I looked at the coast of Africa, and I saw that they fitted together. Everyone says “coincidence”, but the five-year-old child that still lives within me says no, this cannot be. This is not a coincidence. This is the explanation for why the world is as it is.