Abstract
AS the technique of radio-frequency measurement and application has progressed to successively higher frequencies, various investigators have from time to time turned their attention towards a demonstration of the interchangeability of thermal and radio methods of detecting electromagnetic waves. The use of normal radio receiving technique to detect thermal radiation from a hot body has always been an attractive line of experiment; and for this purpose, the sun, in spite of its great distance away from the earth, would appear to offer considerable advantages as a source of radiation of the desired type. The practicability of the reception and measurement of so-called 'cosmic noise' on an ordinary radio receiver has been demonstrated in various investigations, notably those described during 1932–39 by K. G. Jansky, who worked on frequencies of the order of 10–20 megacycles per second, and later (1940–44) by G. Reber, who described corresponding measurements made at frequencies of 160 Mc./s. In these cases, the investigators concluded that the radiation which they measured originated in interstellar space, and, from observations made of the direction of arrival, it was considered that the source of this cosmic noise was closely associated with the Milky Way. Both Jansky and Reber made attempts to observe any 'noise' radiation received from the sun, but although recently (Astrophys. J., Nov. 1944) the latter investigator claims to have obtained definite evidence of this, the amount of such radiation received at the above frequencies is very small.
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Radio Waves from the Sun. Nature 156, 273–274 (1945). https://doi.org/10.1038/156273a0
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DOI: https://doi.org/10.1038/156273a0