1873 – Born on the 25th of May in Riesbach, Switzerland.
Close friend of Albert Einstein at the Federal Polytechnic Institute in Zurich.
Credited with introducing Einstein to the works of Ernst Mach, the skeptical critic of physics.
1955 – Michele Angelo Besso died on 15th of March in Genova, Italy.
Einstein called Besso "the best sounding board in Europe" for scientific ideas.