4.8.2 - Red-shift

what is red-shift?

to the observed increase in the wavelength of light from most distance galaxies.

The further away the galaxies, the faster their moving and the bigger the observed increase in wavelength

it suggests that light is moving away from us.

More distant galaxies have greater red shifts suggesting their moving away faster than nearer ones

what does red shift entail?

That space itself and the universe is expanding

what theory does this support?

the Big Bang theory

what is the Big Bang theory?

Theory that suggests the universe began from a very small region that was extremely hot and dense

then this space exploded - and that since 1998 observations of supernovae suggest that distant galaxies are receding every faster

dark matter?

name given to the unknown substance which holds galaxies together - but dies not emit any em radiation

dark energy?

what is through to be responsible for the accelerated expansion of the universe