Nils Gustaf Dalén
DOI: 10.1063/PT.5.031363
Today is the birthday of Nils Gustaf Dalén, who was born in Stenstorp, Sweden, in 1869. He set out to become a dairy farmer but then changed course and studied engineering at the Chalmers Institute in Gothenburg, Sweden. In 1907 Dalén invented the sun valve, which enabled a beacon to light automatically at dusk and extinguish itself at dawn. The invention enabled lighthouses to function without an attendant on hand for months at a time. He also developed a substance that made handling acetylene, a highly explosive gas used for fuel, far more safe. Dalén received the 1912 Nobel Prize in Physics for his invention of the sun valve.
Date in History: 30 November 1869
