Operation Totem km north west of Woomera, South Australia. A natural claypan known as the Dingo Claypan provided a ready-made airstrip. In August 1952, Sir William Penney, the Chief Superintendent Armament Research (CSAR) at the British Ministry of Supply, and the head of the British atomic weapon development effort, notified W. A. S. Butement, the Chief Scientist at the Australian Department of Supply, of his intention to visit the site before the Hurricane test. Butement warned Penney that it was very remote, and that Beadell and his companions might well have been the first non-Aboriginal people to see the area. Sir John
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