Ch20 cosmology Flashcards
(5 cards)
1
Q
What is an astronomical unit?
A
The average distance between the sun and the earth.
1Au = 1.496e+11m
2
Q
What is a light year?
A
is the distance traveled by moving at the speed of light for a year.
1Ly = 3.0x10^8 x (60x60x24x365)
=9.5x10^15m
3
Q
what is the cosmological principle
A
the universe is isotropic and homogeneous and the laws of physics are universal
4
Q
what does homogeneous and isotropic mean
A
homogeneous: uniform distrbution of matter is the universe.
isotropic: the universe looks the same in all directions
5
Q
Dobbler shift.
A
Dobblers equation
Red shift = v/c
Red shift can be gives as % or decimal.
