Karl G. Jansky

Sixty years ago this month, the PROCEEDINGS OF THE INSTITUTE OF RADIO ENGINEERS (IRE) included Karl Jansky’s classic paper reporting reception of “electromagnetic waves of an unknown origin” but believed to be from “some source outside the solar system.” Jansky, a research engineer with the Bell Telephone Laboratories, stated that he initially had detected the mysterious waves in 1931 and had continued with a “comprehensive study of them ” during 1932. He had used a slowly rotating directional antenna, a receiver tuned to 14.6 m, and a chart recorder to obtain data on the direction and intensity of the waves as a function of time. Analysis of the data led Jansky to conclude that “the waves come, not from the sun, but from a direction which remains constant throughout the year.” He noted that the waves seemed to come approximately from the direction of Sagittarius in the Milky Way although his system was not accurate enough to identify a specific source. Continue reading