Week 9 Cosmology: The expanding Universe Flashcards
define Olber’s paradox
In an infinite Universe the sky would be infinitely bright due to stars being in every conceivable direction and as bright as the Sun
what are the two conclusions we can make from Olber’s paradox
the Universe is not infinte and has an age
what did Lemaitre discover in 1927
that almost all galaxies are moving away from us and their velocities increase linearly with distance from us
what is the hubble velocity equation
v = H0r
H0 is the hubble constant
what is hubble time and its equation
it is the time that has elapsed since the start of the expansion
t = 1 / H0
what does the Hubble-Lemaitre Law indicate
the universe has a finite age and therefore a finite size
what is the hubble radius and its equation
it is the radius of the universe at a set moment
r = ct(hubble)
what is the redshift equation for velocities that satisfy v
z = Δλ / λ0 = v / c
used for distances between galaxies
how does redshift differ with distance of a galaxy
the further away a galaxy is the greater it is redshifted
what is the large distance redshift equation when v > 0.1c
1+z = sqrt[ (1+v/c) / (1-v/c) ]
