how can you relate the density parameter to redshift if in a matter and or cosmological constant dominated universe
2006-11-14 09:13:07 · 2 answers · asked by Aquabug222 1 in Science & Mathematics ➔ Astronomy & Space
The density parameter will tell you how the expansion of the universe, as measured by redshift, evolves over time. You can't relate it to the redshift of objects at a particular distance, but if you measure redshift for MANY distances and see what the expansion rate was at different epochs of the universe's history (looking at larger distances means looking back in time) then you get a sense of how quickly the matter in the universe is slowing the expansion. The rate of slowing depends on the density.
2006-11-14 13:49:12 · answer #1 · answered by Mr. Quark 5 · 0⤊ 0⤋
If the universe is more dense than we currently think then it will stop expanding and collapse back on itself which would cause blue-shift.
If it truly is as dense as we currently measure it to be then it will continue expanding forever causing redshift.
The correlation of density vs. expansion are the properties of gravitational force at play.
More density equals more gravity, less density in turn equals less gravity.
More density= more gravity= collapsing universe= blueshift.
Less density= less gravity= Infinitely expanding universe= redshift.
An infinitely expanding universe is the assertion that modern physics and astronomical data provide us with at present.
2006-11-14 19:01:28 · answer #2 · answered by tx_buffalo_matador 1 · 0⤊ 1⤋