Option D.3 Flashcards
Olbers’ Paradox
The contradiction that in an infinite, homogenous and static universe populated with stars, the night sky should be glowing bright with star light from all directions
Cosmic scale factor definition and formula
A measure of the relative expansion of the universe
H(t) = Rate of change of R(t) divided by R(t)
How does the universe expand?
By taking space itself and expanding its scale in time
Hubble parameter
A measure of the rate at which space in the universe expands
What is an object seen at a certain red shift seen as?
The object is seen as how it was when the light was emitted
Standard candle
An astrophysical object with a known luminosity due to some physical characteristic
Gravitationally bound system
A system in which local gravity has to be considered in addition to the expansion of the universe to describe motions within that system
Isotropy
When something has the property of being the same in all directions
