by mk

  At Harvard University in 1951
  Harold Ewen pointed his antenna past the sun.
  He used a waveguide horn, ten feet long and half that wide,
  That drove a mixer with a 1N21 inside.

  Ewen and Purcell caught the radiation line
  Of interstellar hydrogen, a most important find.

  A klystron signal generator as a switched LO,
  At thirteen-ninety-three into the diode it would go.
  At twenty-seven megs, they amplified a million fold.
  Upon the Angus chart recorder, what did they behold?

  Ewen and Purcell caught the radiation line
  Of interstellar hydrogen, a most important find.

  Ewen could detect the twenty centimeter line!
  He showed his data to Purcell, who thought that it was fine.
  He wrote a dissertation, and it wasn't very long.
  It had as many pages as the lines within my song.

http://www.setileague.org/songbook/hydrogen.htm