Theodor Svedberg (1884-1971) was awarded the 1926 Nobel Prize for Chemistry for his work on disperse systems. His initial work with colloids supported the theories of Brownian motion put forward by Albert Einstein and Polish geophysicist Marian Smoluchowski. Svedberg studied the physical properties of colloids, such as their diffusion, light absorption, and sedimentation, which led to physical laws describing disperse systems. He also developed the technique of analytical ultracentrifugation and demonstrated its utility in distinguishing among proteins. Svedberg found that the size and weight of particles, determined the rate at which they settle out, also called sedimentation, and he used this information to measure their size. He also determined the molecular weights of complex proteins such as hemoglobin and properties of carbohydrates and other high polymers. The Svedberg Unit (symbol S, sometimes Sv), which is used in ultracentrifugation, was named after Svedberg.