Time’s arrow: Albert Einstein’s letters to Michele Besso

Cataloguing the letters from Albert Einstein to his closest friend, Michele Besso, was a roller-coaster ride: intellectually exhilarating, funny, endearing — and with an unexpected conclusion.

Michele Besso and Einstein first met as students in Zurich in the late 1890s, and their friendship was cemented during their time working together in the early 1900s in the Swiss federal patent office in Bern. In the evenings after work, the two friends would stroll home together, and many years later Einstein would remember how thoughts of everyday life would fall away as they discussed scientific subjects. When Einstein changed the world of physics for ever in 1905 with four groundbreaking papers, Michele Besso was his only acknowledged collaborator. 

It was because of their close intellectual understanding that Einstein felt able to talk freely and in detail to Besso about the key scientific concepts of his career: special and general relativity, the ‘cosmological constant’, the red shift of spectral lines, ‘time’s arrow’, unified field theory, quantum mechanics and much else. For a non-scientist it was hard — sometimes impossible — to keep up, but the sensation of observing this great mind working at full speed was extraordinary. 

The letters also reveal the human side of Einstein: walking in the mountains with his young son, making fun of crusty old colleagues in Berlin, grumbling about being shown off ‘like a prize bullock’ on an early tour of the United States, dying of boredom in a League of Nations meeting. You feel his anguish and remorse as his first marriage breaks down and he becomes estranged from his children. There are plenty of jokes, too, about himself, his fame, being Jewish, getting old — even about quantum physics.

Above all, there is his delight in his work, his relish for a new theory, his sense of elevation when grasping at fundamental truths — which he expresses in one letter as ‘getting closer to God’.

Working through these 56 letters was almost like getting to know Einstein himself. What’s more, this was a particularly attractive side of him, the side that his closest friend saw over 50 years. The most striking parts of his personality? His humility, his absolute love of what he did — at one point, he says, ‘I would not want to go on living if I didn’t have my work’  — and his ability, through that extraordinary mind, to see the universe in a perspective that is beyond the rest of us. 

Michele Besso died in March 1955, and the very last letter in the correspondence is written to members of Besso’s family a few days later, and just weeks before Einstein’s own death at the age of 76. The letter ends with a famous sentence, which reflects their deep friendship and the scientific understanding they shared, as well as the distance they had travelled since those happy days as patent clerks in Bern: ‘Now he has again preceded me a little in parting from this strange world. This has no importance. For people like us who believe in physics, the separation between past, present and future has only the importance of an admittedly tenacious illusion.’

After I had finished cataloguing this letter, I sat staring at my computer for a moment, and then I did something I’ve never done before in nearly 20 years of cataloguing autograph letters. I burst into tears.