Archive for Freeman Dyson

R.I.P. Freeman Dyson (1923-2020)

Posted in The Universe and Stuff with tags , on February 29, 2020 by telescoper

I was just about to leave work last night when I heard via social media the sad news of the death at the age of 96 of the theoretical physicist Freeman Dyson.

Overnight the regular media have been running tributes to him, and various friends and colleagues have been posting their own personal recollections of a remarkable scientist who also seems to have been a kind and generous human being.

I never had the opportunity to meet, or even correspond with, Freeman Dyson myself but I do recall from Nottingham times being told that both Dyson and Julian Schwinger visited and gave lectures for the bicentennial celebrations of the birth of George Green. People there remembered him with fondness.

Please feel free to share any personal reminiscences through the Comments Box below.

Freeman Dyson was an original and creative thinker who was by no means always right but I’ve always felt that scientists should be judged by their best work rather that their worst, and Dyson was a wonderful generator of ideas and made important and influential contributions across a wide range of fields from Quantum Electrodynamics and Solid State Physics to Astronomy and Cosmology.

Rest in peace, Freeman Dyson (1923-2020).

Dyson on Eddington

Posted in Books, Talks and Reviews, The Universe and Stuff with tags , , , , , , on April 10, 2012 by telescoper

I’m grateful to George Ellis for sending me a link to a book review written by Freeman Dyson that appeared in a recent  edition of the New York Review of Books. I was particularly interested to read the following excerpt about Arthur Stanley Eddington. I have been intrigued by Eddington since I wrote a book about his famous expeditions (to Principe and Sobral) in 1919 to measure the bending of light by the Sun as a test of Einstein’s general theory of relativity; I blogged about this on its ninetieth anniversary, by the way, in case anyone wants to read any more about it.

Although I read quite a lot about Eddington, not only during the course of researching the book but also afterwards, as there are many things about his character that fascinate me. He died long before I was born, of course, but whenever I meet someone who knew him I ask what they make of him. Not altogether surprisingly, opinions differ rather widely from one person to another as his character seems to have been extremely contradictory. He doesn’t seem to have been very good at small talk, but was nevertheless a much sought-after dining companion. He was a man of great moral integrity, but at times treated his colleagues (notably Chandrasekhar) rather shamefully. He was a brilliant astrophysicist, but got himself hooked on his peculiar Fundamental Theory which was a dead end. He remains an enigma.

Anyway, this is what Dyson has to say about him:

Eddington was a great astronomer, one of the last of the giants who were equally gifted as observers and as theorists. His great moment as an observer came in 1919 when he led the British expedition to the island of Principe off the coast of West Africa to measure the deflection of starlight passing close to the sun during a total eclipse. The purpose of the measurement was to test Einstein’s theory of General Relativity. The measurement showed clearly that Einstein was right and Newton wrong. Einstein and Eddington both became immediately famous. One year later, Eddington published a book, Space, Time and Gravitation, that explained Einstein’s ideas to English-speaking readers. It begins with a quote from Milton’s Paradise Lost:

Perhaps to move
His laughter at their quaint opinions wide
Hereafter, when they come to model heaven
And calculate the stars: how they will wield
The mighty frame: how build, unbuild, contrive
To save appearances.

Milton had visited Galileo at his home in Florence when Galileo was under house arrest. Milton wrote poetry in Italian as well as English. He spoke Galileo’s language, and used Galileo as an example in his campaign for freedom of the press in England. Milton had witnessed with Galileo the birth struggle of classical physics, as Eddington witnessed with Einstein the birth struggle of relativity three hundred years later. Eddington’s book puts relativity into its proper setting as an episode in the history of Western thought. The book is marvelously clear and readable, and is probably responsible for the fact that Einstein was better understood and more admired in Britain and America than in Germany.

As a student at Cambridge University I listened to Eddington’s lectures on General Relativity. They were as brilliant as his books. He divided his exposition into two parts, and warned the students scrupulously when he switched from one part to the other. The first part was the orthodox mathematical theory invented by Einstein and verified by Eddington’s observations. The second part was a strange concoction that he called “Fundamental Theory,” attempting to explain all the mysteries of particle physics and cosmology with a new set of ideas. “Fundamental Theory” was a mixture of mathematical and verbal arguments. The consequences of the theory were guessed rather than calculated. The theory had no firm basis either in physics or mathematics.

Eddington said plainly, whenever he burst into his fundamental theory with a wild rampage of speculations, “This is not generally accepted and you don’t have to believe it.” I was unable to decide who were more to be pitied, the bewildered students who were worried about passing the next exam or the elderly speaker who knew that he was a voice crying in the wilderness. Two facts were clear. First, Eddington was talking nonsense. Second, in spite of the nonsense, he was still a great man. For the small class of students, it was a privilege to come faithfully to his lectures and to share his pain. Two years later he was dead.