Leif Tronstad

Born on 27 March 1903, Leif Tronstad was a Norwegian chemist who during World War II helped thwart the Germans’ efforts to build an atomic weapon. Educated at the Norwegian Institute of Technology, Tronstad (left in the photo above) stayed on as a research fellow and lecturer before becoming a full professor in 1936. Specializing in surface chemistry, Tronstad became interested in heavy water, which had been discovered in the fruitful year of 1932 . As a consultant for Norsk Hydro, he was instrumental in the building of the Vemork heavy water reactor near Rjukan. When Germany invaded Norway in 1940, Tronstad, who was also an officer in Norway’s military, joined the Norwegian resistance. After being forced to flee to the UK in 1941, he continued his resistance efforts and masterminded an attack on the Vemork reactor, called Operation Gunnerside, to try to prevent Germany from using it to build a nuclear bomb. In 1944 Tronstad parachuted back into Norway as part of Operation Sunshine to secure key infrastructure before the Germans could destroy it. However, on 11 March 1945, he was ambushed and killed while interrogating a Nazi sympathizer. (Photo credit: Henrik Aamodt, CC BY-SA 4.0 )

Date in History: 27 March 1903