RED SHIFT AND BLUE SHIFT

RED SHIFT AND BLUE SHIFT

1. The universe is always expanding red shift gives good evidence

   • Further away a galaxy = greater red shift so more distant galaxies are moving faster
     • measurements of red-shift show galaxies to be moving away from us very quickly in all directions.

2. As galaxies move away from us the frequency of light waves decreases and waves become longer this causes us to see the light closer to the red end of the light spectrum so its red-shifted this is similar to a car travelling away from us as it sounds lower pitched as it moves away due to again lower frequency of waves and longer wavelength.

   • BLUE SHIFT
     • Exactly the same theory as red shift but objects moving towards us have higher frequency light waves and shorter wavelength so the light is blue shifted.

3. provides evidence that the whole universe is expanding