1 The universe is always expanding
red shift gives good evidence
1.1 Further away a galaxy = greater
red shift so more distant
galaxies are moving faster
1.1.1 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.
2.1 BLUE SHIFT
2.1.1 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