Photo from the Nobel Foundation archive.
Nils Gustaf Dalén
The Nobel Prize in Physics 1912
Born: 30 November 1869, Stenstorp, Sweden
Died: 9 December 1937, Stockholm, Sweden
Affiliation at the time of the award: Swedish Gas-Accumulator Co., Lidingö-Stockholm, Sweden
Prize motivation: "for his invention of automatic regulators for use in conjunction with gas accumulators for illuminating lighthouses and buoys."
Prize share: 1/1
Gustaf Dalen was born in Stenstorp in the Västergötland province of Sweden. Rather than take over the family farm, he studied at Chalmers University of Technology in Gothenburg and ETH in Zurich. He subsequently worked in private industry, including at the Da Laval's Steam Turbine Company and, primarily, at AGA, which under his leadership evolved into a global enterprise. He lost his sight in 1912 in an accidental explosion in connection with an experiment but remained active as an industrial leader. He was married and had four children.
For centuries, lighthouses have made navigation safer. In the 19th century, acetylene gas began to be used to light their beacons. Gustaf Dalén developed a method for emitting short flashes of light, thereby reducing gas consumption. In 1907 he invented a regulating valve based on the difference in expansion between black and white metal rods. This "solar valve" could extinguish beacons during daytime, saving more money.