Operation Mosaic Captain Hugh Martell would be in charge as commander Task Force 308, with the temporary rank of commodore. Charles Adams from Aldermaston, who had been the deputy technical director to Leonard Tyte for Operation Hurricane and to William Penney on Operation Totem, was appointed the scientific director for Operation Mosaic, with Ieuan Maddock as the scientific superintendent. Group Captain S. W. B. (Paddy) Menaul would command the Air Task Group. Menaul was also a nuclear test veteran, having been an observer on board Vickers Valiant WZ366 when it had made the first operational drop of a British atomic bomb during
Atomic clock of using atomic transitions to measure time was suggested by Lord Kelvin in 1879. Magnetic resonance, developed in the 1930s by Isidor Rabi, became the practical method for doing this. In 1945, Rabi first publicly suggested that atomic beam magnetic resonance might be used as the basis of a clock. The first atomic clock was an ammonia absorption line device at 23870.1 MHz built in 1949 at the U.S. National Bureau of Standards (NBS, now NIST). It was less accurate than existing quartz clocks, but served to demonstrate the concept. The first accurate atomic clock, a caesium standard based on