8.14 describe evidence that supports the Big Bang theory (red-shift and cosmic microwave background (CMB) radiation)
If we examine the light spectra for distant galaxies we can see that the wavelengths of the light have become longer. We call this stretching of the waves ‘red-shift’. It tells us that the galaxies producing the light are moving away from us .The further away a galaxy is, the greater its red-shift, so it is moving even faster. This is evidence that the Universe is expanding and so it supports the Big Bang Theory.
Microwave radiation can be detected EVERYWHERE in the Universe. These are the stretched remains of high energy gamma radiation that would have been produced in the explosion that created the Universe. They have stretched because the Universe is expanding.