Astronomy Flashcards
where did the universe begin 14 billion years ago
very small region that was extremely hot and dense
Then there was a giant explosion, which is known as the Big Bang
what did the big bang cause
This caused the universe to expand from a single point, cooling as it does so, to form the universe today
Each point expands away from the others
what does it mean if the galaxies are further away
the further away they are the faster they move
what is the steady state theory
as galaxies move apart, new ones will be formed in the gaps in between them
This implies the density of galaxies remains the same as the universe expands
what does steady state believe
always existed more or less as it is seen now
what is the evidence for big bang
Red shift and CMB
what is red shift
to prove galaxies are moving away from each other we can say that:
- different elements absorb different frequencies of light
- each element produces specific patter of dark lines corresponding the frequency is absorbs on EM spectrum
- now looking at light from distant galaxies we can see the same patterns but at lower frequencies
- higher wave length therefore pattern shifted towards red end of spectrum - red shift
- this suggest that all distant galaxies are moving away
- distant galaxies have greater red shift - higher wave length
how does heavier matter move
travel at a slower speed, closer to the source of the explosion
what is CMB radiation
according to big bang theory universe was very hot and dense therefore must’ve emitted thermal energy.
this is microwave radiation = detected that low frequency electromagnetic radiation coming from all parts of universe mainly microwave part
why does CMB only back up big bang theory
as it shows that the universe had a beginning whereas steady state theory states there was no beginning or end
