Radio Waves and Radio Telescopes – UPSC Prelims

Radio Waves and Radio Telescopes:
  • Radio waves have the longest wavelengths in the electromagnetic spectrum. They range from the length of a football to larger than our planet. Heinrich Hertz proved the existence of radio waves in the late 1880s.
  • Radio telescopes collect weak radio light waves, bring it to a focus, amplify it and make it available for analysis.
  • They help study naturally occurring radio light from stars, galaxies, black holes, and other astronomical objects.
  • These specially-designed telescopes observe the longest wavelengths of light, ranging from 1 millimetre to over 10 metres long. For comparison, visible light waves are only a few hundred nanometres long, and a nanometre is only 1/10,000th the thickness of a piece of paper. In fact, we don’t usually refer to radio light by its wavelength, but by its frequency.