Besso was born in Riesbach of Jewish Italian (Sephardi) descent. He was a close friend of Albert Einstein during his years at the Federal Polytechnic Institute in Zurich, today the ETH Zurich, and then at the patent office in Bern. Besso is credited with introducing Einstein to the works of Ernst Mach, the sceptical critic of physics who influenced Einstein's approach to the discipline. Einstein called Besso "the best sounding board in Europe" for scientific ideas.
Besso died in Geneva, aged 81. In a letter of condolence to the Besso family, Albert Einstein included his now famous quote "Now he has departed from this strange world a little ahead of me. That means nothing. People like us, who believe in physics, know that the distinction between past, present and future is only a stubbornly persistent illusion." Einstein died one month and 3 days after his friend, on 18 April 1955.
- Einstein and Besso:From Zürich to Milano by Christian BRACCO
- Einstein as a Student
- Einstein the Early years
- Calaprice, Alice; Lipscombe, Trevor (2005). Albert Einstein: A Biography. Greenwood Publishing Group. p. 24.