Cosmic Microwave Background

The Cosmic Microwave Background (CMB) is a form of electromagnetic radiation dating from an early stage of the universe. It is the oldest known form of radiation.

About the Cosmic Microwave Background
  • With a traditional optical telescope, the space between stars and galaxies is completely dark but a sufficiently sensitive radio telescope reveals the CMB as a faint glow not associated with any star, galaxy, or other object.
  • The glow of the cosmic microwave background is strongest in the microwave region of the electromagnetic spectrum.
  • The CMB was initially composed of gamma wave radiation of an infinitely small wavelength, but the expansion of the Universe over time means it arrives today as microwave radiation.
  • The CMB is detected as an emission of uniform thermal energy, a faint glow coming from all parts of the sky.
  • The CMB is considered to be evidence for the Big Bang theory.