The Strangest Man: The hidden life of Paul Dirac, quantum genius
Graham Farmello, Faber & Faber, 2009, ISBN 978-0-571-22286-5, 539pp
Quantum physics is one of the great mysteries of the universe. Of course, the quantum physicists will tell you that it’s all a matter of mathematics and experimental observation but that doesn’t mean they understand it; they don’t. I took a short course on quantum theory in 1969 and I can remember nothing probably because I understood nothing. One of its pioneers was Werner Heisenberg who rather blotted his copy book by cooperating with the Nazis in their attempt to develop an atomic bomb before the Allies. He has a famous principle that applies to subatomic particles. I paraphrase and I take poetic license but, he says, that you can know how fast it is going or where it is but you cannot know both at the same time. Heisenberg thought this applied to subatomic particles but in my experience, it also applies to most teenagers.
The other day I read on the ABC news website that Chinese scientists have smashed the quantum entanglement distance record. Quantum physics identifies a process called entanglement, where the properties of two particles affect each other, even when those particles are separated by large distances. That means that when one particle does something its friend does the same thing … even though, as these Chinese people have demonstrated, the particles are 1200 kilometres away. Figure that out.
The physics we learned at school many years ago was largely based on Newton’s so-called classical principles which work quite well for us in our daily life. But Einstein’s famous E = mc2 equation and his associated theory of relativity showed that Newton may not always be right. Einstein was dealing in large distances and high speeds. At the other end of the scale late 19th and early 20th century physicists were trying to understand the atom and its structure. Rutherford thought an atom looked like a little solar system with a large nucleus and electrons rotating around it. You must be a bit peculiar to step into subatomic physics. After all you cannot see anything that’s subatomic, there’s an awful lot of incomprehensible mathematics and the people are weird.
Paul Dirac (1902 – 1984) was one of these theoretical physicists who was probably autistic but in those days was just regarded as eccentric. The cover of this biography claims that the book is a “must-read page-turner”. It’s not quite that exciting but I was surprised to find myself reading it avidly and enjoying it hugely. Perhaps that is due in part to the writing skills of its author who is well-known for his work on science communication. Dirac is famous for an equation that describes the behaviour of electrons but there is not a single equation in this book; there is no mathematics to get in the way. Instead you read about a man who just happened to be a brilliant mathematician. Dirac was the Lucasian Professor of Mathematics a post held previously by Isaac Newton and subsequently by Stephen Hawking. Dirac’s contributions to our understanding of particle physics are significant. Quantum computing is coming and will depend to an extent of Dirac’s equations.
As I read this book I was amused by the emotional detachment that Dirac displayed. He didn’t do emotion; he didn’t like talking to people and he found it hard to recognise faces. In February 1930, when he was 28, he sent a postcard to his mother with ten words describing the weather in Cambridge. He clearly didn’t think that his recent election as a Fellow of the Royal Society, probably the highest honour in British science, was important enough. Surprisingly enough he married and adopted his Hungarian wife’s two children and had two of his own. Being married to an emotionally detached autistic man would be frustrating. According to one story his wife once shouted at him “what would you do if I left you?” Dirac thought for a moment and said, “I’d say ‘Goodbye, dear’.” I need to remember that one.
He was a member of the Papal Academy, which is a group of distinguished scientists that gives objective scientific advice to the Pope. He was probably an atheist and that gave his supporters a problem after his death. They were keen that he should have a memorial in Westminster Abbey. But for that to happen he needed to be a Christian or at least not be inimical to religion. The Abbey authorities eventually agreed to his commemoration in the Abbey on the basis that he had been christened and was, therefore, theoretically a Christian. At the service of commemoration, the address was given by Stephen Hawking who described him as “probably the greatest British theoretical physicist since Newton”. If you have any interest in physics and in reading about its characters then this is a book for you. Dirac takes centre stage but you will read about Pauli, Jordan, Kapitza, Heisenberg, Bohr, Rutherford and Cockburn and see how early 20th century physicist succeeded in spite of itself.
One last thing I found in this book is an amusing puzzle. The challenge is to express any whole number using the number two (2) exactly four times. The first few numbers are:
1 = (2 + 2) / (2 + 2)
2 = (2 / 2) + (2 / 2)
3 = (2 x 2) - (2 / 2)
4 = 2 + 2 + 2 - 2
but it gets hard pretty quickly. I had never seen this before. It was played extensively at Göttingen (before the Nazis crushed that wonderful university). Try it.