decade from 1937 on he was the world's only radio astronomer, a field that only expanded after World War Two when scientists, who had gained a great deal of knowledge during the wartime expansion of RADAR, entered the field, starting with Project Diana. During this time he uncovered a mystery that was not explained until the 1950s. The standard theory of radio emissions from space was that they were due to black-body radiation, light (of which radio is a non-visible form) that is given off by all hot bodies. Using this theory one would expect that there would be considerably more high-energy light than low-energy, due to the presence of stars and other hot bodies. However Reber demonstrated that the reverse was true, and that there was a considerable amount of low-energy radio signal. It was not until the 1950s that synchrotron radiation was offered as an explanation for these measurements. Reber sold his telescope to the National Bureau of Standards, and it was erected on a turntable at their field station in Sterling, Virginia. Eventually the telescope made its way to the National Radio Astronomy Observatory in Green Bank, West Virginia, and Reber supervised its reconstruction at that site. Reber also helped with a reconstruction of Jansky's original telescope. Medium frequency research Starting in 1951, he received generous support from the Research Corporation in New York, and moved to Hawaii. In the 1950s, he wanted to return to active studies but much of the field was already filled with very large and expensive instruments. Instead he turned to a field that was being largely ignored, that of medium frequency (hectometre) radio signals in the 0.5–3 MHz range, around the AM broadcast bands. However, signals with frequencies below 30 MHz are reflected by an ionized layer in the Earth's atmosphere called the ionosphere. In 1954, Reber moved to Tasmania, the southernmost state of Australia, where he worked with Bill Ellis at the University of Tasmania. There, on very cold, long, winter nights the ionosphere would, after many hours shielded from the sun's radiation by the bulk of the Earth, 'quieten' and de-ionize, allowing the longer radio waves into his antenna array. Reber described this as being a "fortuitous situation". Tasmania also offered low levels of man-made radio noise, which permitted reception of the faint signals from outer space. In the 1960s, he had an array of dipoles set up on