Red Shift

• There is an observed increase in the wavelength of light from most distant galaxies
• The further away the galaxies, the faster they are moving and the bigger the observed increase in wavelength ; this effect is called red-shift
• The observed red-shift provides evidence that space itself (the universe) is expanding and supports the Big Bang theory
• The Big Bang theory suggests that the universe began from a very small region that was extremely hot and dense
• Since 1998 onwards, observations of supernovae suggest that distant galaxies are receding ever faster
• There is still much about the universe that is not understood, for example dark mass and dark energy
• Evidence for the Big Bang includes cosmic microwave background radiation