The Universe Flashcards
1
Q
What is Hubble’s law?
A
v=H_0 d
Where v is the recession speed
2
Q
What is Hubble’s constant?
A
H_0=(72.1± 2.0) km s^-1 Mpc^-1
3
Q
How can we find the age of the universe?
A
t_0=d/v=(H_0)^-1=13.6 Gyr
For H_0 independent of time
4
Q
What is the equation for red shift?
A
1+z=λ/λ_0
z=H_0 d/c
5
Q
How does the red shift related to velocity?
A
v=cz
6
Q
What is CMBR?
A
The radiation left over from when the universe first became optically thin
Evidence of the big bang theory
7
Q
What is the big bang theory?
A
The idea that the universe was once in a hot and dense state before expansion
8
Q
What is the evidence for the big bang theory?
A
CMBR
Expansion of the universe detected by Hubble
9
Q
What is the density of the universe?
A
ρC =3(H_0)^2/(8πG)
