Abstract :
Astronomers have likened the visible region of the electromagnetic spectrum which stretches from short-wave gamma rays at one end and the long radio waves at the other to an infinitesimally small window looking out on the universe. Until the last decade, nearly everything we knew about the planets, stars, and galaxies came to us borne on light waves in this narrow, visible portion of the spectrum, but our small window is continually opening wider. At the Harvard College Observatory, astronomers, who have studied the stars through the telescope, the spectroscope, and the photograph, have recently been developing a whole new battery of electronic instruments for searching the heavens telescopes, cameras, radiometers, spectrometers, and spectrographs. The laboratories of Harvard College Observatory, associated with the Smithsonian Astrophysical Observatory, have become modern electronic workshops. Three of the new electronic instruments each peer through a different window in the electromagnetic spectrum: the infrared, the far ultraviolet, and the radio.
