Chilling with Einstein

Before becoming a professor of physics, Albert Einstein worked as a patent clerk. Familiar with the process, he submitted a number of his own patents including a camera that self-adjusts to the ambient light level and an electromagnetic sound reproduction device. A number of his patents were related to refrigeration, a project on which he collaborated with nuclear physicist Leo Szilard. In the 1920s, Szilard was a frequent visitor to Einstein’s home. One day, after he had read a report of a family who had been killed by the toxic gases leaking from their refrigerator, Einstein commented to Szilard that, “There must be a better way.” The two physicists devised and patented multiple designs for new refrigerators based on principles including absorption, diffusion and electromagnetism. The Swedish company AB Electrolux bought the patent for the absorption refrigerator for $750 and subsequently the diffusion design, though never developed either appliance. Einstein and Szilard also collaborated on the design of an electromagnetic pump, which they assumed would be silent. Instead, due to cavitation (the formation of bubbles) in the fluid, contemporaries reported the pump “howled like a jackal”.