Saturday, September 05, 2009

Tell Cockroft and Maud Ray Kent

I have recently been reading up on the early history of atomic research; it's rather fascinating, and it's an area where you keep coming up against unexpected things. For instance, uranium fission kept being rediscovered, but nobody recognized it as uranium fission: they thought they were creating new transuranic elements, and were thoroughly perplexed at the results they were getting, because it took an immense amount of work for them to find a way to make sense of the idea that you could start with uranium, element 92, and get thorium, element 90, by adding to it. Likewise, you'd have thought that pressure to build atomic weapons would have come from governments; but in fact what you find are scientists repeatedly trying to get governments interested in an atomic weapons program and repeatedly failing.

One of the interesting stories begins as Nazi Germany was reaching out to take hold of Denmark. Worried, Niels Bohr sent his children's governess, who was English, back to England and tried to get his affairs in order. The Nazis crossed the border, took the ports; Bohr fired off an urgent telegram to his colleague, Otto Frisch, who was currently in Birmingham. It ended: "Tell Cockroft and Maud Ray Kent." Frisch gave it to John Cockroft, one of Britain's leading atomic researchers, and Cockroft read Bohr's telegram to the Committee for the Scientific Survey of Air Warfare. What did Bohr mean with the bit about 'Maud Ray Kent'? Nobody knew anyone of that name. Someone pointed out that the letters could be a slightly modified anagram for 'Radium Taken'; the Germans perhaps were making a concerted effort at advancing in atomic research? That fit with other evidence. But what could the Germans be interested in when it came to atomic research? Radium itself had long ceased to be the central element in the study; but radium is closely associated with uranium, whose potential power when made to disintegrate was just beginning to be guessed at. Someone suggested that the 'Maud' might actually stand for "Military Application: Uranium Disintegration". And by that point everyone knew that there was one obvious military application for uranium disintegration: an atomic bomb. And so the MAUD Committee was born, to push for Britain's own atomic weapons program to counterbalance the one that Bohr had warned the Nazis were creating.

It was after the war that someone discovered that Bohr's English governess was named Maud Ray, and that she lived in Kent.