Cosmology: The Origin and Evolution of the Universe. The universe shows structure at many scales subatomic particles atoms stars and planets star clusters and galaxies galactic cluster and superclusters voids and sheets. Does this structure ever end? .
Explains the features of the universe
Present data favors this model of cosmology
Follows Einstein's General Theory of Relativity
The Universe is not expanding into empty space
This idea comes from watching explosions
Instead, space-time itself is expanding and carrying galaxies along with it
Another question: are we really at the center of the expansion?
We cannot see objects beyond this distance because light from these objects has not had enough time to reach us
3 Possibilities in Einstein's General Theory of Relativity:
If ρ0 is greater than ρc, the density parameter Ω0 has a value greater than 1, the universe is closed, and space is spherical (with positive curvature)
If ρ0 is less than ρc, the density parameter Ω0 has a value less than 1, the universe is open, and space is hyperbolic (with negative curvature)
Open, closed, or flat?
Observations of temperature variations in the cosmic microwave background indicate that the universe is flat or nearly so, with a combined average mass density equal to the critical density
combined average mass density
cosmic background radiation
cosmic microwave background
cosmic light horizon
dark energy density parameter
era of recombination
mass density of radiation
matter density parameter
zero curvatureKey Words