Notes on the history of nuclear physics

Reader and Clark reply: We did not write that Allied bombing forced the Germans to abandon the Norsk Hydro heavy water plant in 1942. We wrote that “the Allies undertook to disable the Norsk Hydro plant. Because it was nestled among steep mountains, aerial bombardment was difficult. But eventually Allied bombing forced the Germans to abandon the plant.” The two commando raids that Tom Segalstad mentions were a gripping part of the story of the Norsk plant. Indeed, that was part of our originally submitted article that did not make it to the final draft.

After the successful attack by the Norwegian commandos on 27–28 February 1943, the plant was rebuilt and soon returned to operation. As documented in reference 5 of our article, the plant was bombed by the Americans on 16 November 1943. Knut Haukelid, one of the Norwegian commandos, relates in his book, “But the bombing was successful as far as the production of heavy water was concerned. The management of Norsk Hydro succeeded in convincing the Germans that further manufacture was useless, even after rebuilding; so production at Vermork was stopped.” ¹

Like many films, The Heroes of Telemark occasionally prefers dramatic effect to historical accuracy, but it is a good overall portrayal of the story, can be easily obtained for viewing, and is accessible to a general audience.

Alfred Goldhaber’s remarks are a welcome addition to the story of the heroic era of research treated in our essay. The report of Patrick Blackett and Giuseppe Occhialini is indeed a masterpiece of experimental virtuosity and analysis.