It was Einstein who made the real trouble. He announced in
1905 that there was no such thing as absolute rest. After that there
The field of radio astronomy was first stumbled upon by Karl G Jansky.
He was working at Bell Telephone laboratories in 1932 attempting
to find a way to reduce static in telephone lines generated by thunderstorms
and lightning. He did find what he was looking for but he
also found that there was still static even after the storms were
compensated for. This second interference source seemed to
be present 24 hours a day, and was not associated with anything
man-made. So, this eventually led him to the assumption that
the signal was not originating on earth at all, instead, the signal
seemed to be coming from someplace other than our own solar system.
In fact, the radiation he was detecting was coming from the direction
of the center of the galaxy. This was the first recognized
detection of radio emission from sources other than earth.
Microwave radiation due to transitions between the
hyperfine components of atomic hydrogen in interstellar space was
first detected by Ewen and Purcell and independently by Muller and
Oort(Townes and Schawlow, 146). The region is at 1420.405
MHz and corresponds to a wavelength of 21.11 cm.