Other Free Encyclopedias » Online Encyclopedia » Encyclopedia - Featured Articles » Contributed Topics from F-J

Jansky, Karl Guthe

radio astronomy time war

[yan skee] (1905–50) US radio engineer: discovered first astronomical radio source.

Jansky studied physics at Wisconsin and joined the Bell Telephone Co in 1928. While working for them in 1931 Jansky was given the task of investigating sources of interference to shortwave radio communications. (Causes of static include thunderstorms and nearby electrical equipment.) Using a rotatable directional antenna he detected a weak static emission at a wavelength of about 15 m that appeared at approximately the same time every day. He soon demonstrated that it was coming from the direction of the centre of the Galaxy and suggested in 1932 that it was caused by interstellar ionized gas rather than from the stars. His discovery did not receive much attention at the time, despite its potential value (eg radio waves penetrate dust clouds, which obscure the centre of the Galaxy for optical astronomy), but it was to lead to the development of radio astronomy after the Second World War. The unit of radio emission strength is named after him (1 jansky = 1 W m –2 Hz –1 ). Jansky did not continue in radio astronomy, which was kept alive by until its post-radar expansion after the Second World War.

Jantzen, Inc. [next] [back] Jane Eyre

User Comments

Your email address will be altered so spam harvesting bots can't read it easily.
Hide my email completely instead?

Cancel or