The (Theodor) Svedberg
Born: 30 August 1884, Fleräng, Sweden
Died: 25 February 1971, Örebro, Sweden
Affiliation at the time of the award: Uppsala University, Uppsala, Sweden
Prize motivation: "for his work on disperse systems."
Prize share: 1/1
Albert Einstein's theory of Brownian motion - the random movements of small particles in a liquid - explained that the movements are due to collisions between particles and molecules. Theodor Svedberg's studies helped confirm the theory and thus provided evidence of the physical existence of molecules. In 1925 he also developed the ultracentrifuge, which spins mixtures of different substances at very high speeds. The heavier elements are pulled to the outer edge, and various measurements then allow the calculation of the weight of different molecules