Unit 5 - Astrophysics - Cosmology Flashcards
What is the Doppler effect?
The apparent change in frequency of electromagnetic radiation because of the motion of the source of the radiation or the observer.
How is the red shift, z, calculated?
Define Hubble’s Law.
Hubble’s law states that there is a direct correlation between the distance to the galaxy, d, and its recessional velocity, v, as measured by its red shift.
V=Hd
H is Hubble’s constant
How can the age of the universe be determined?
The reciprocal of Hubble’s constant - when it is consitent with SI units is equal to the age of the universe.
What are the three properties of quasars?
Most distant measurable objects
Very bright radio emitters
Very large optical red shift
State and explain two pieces of evidence for the Big Bang
The redshift of distant galaxies shows that the universe is expanding so if you were to go back in time the universe probably started from a single point as an ‘explosion’
Background microwave radiation suggests that the universe was initially very hot - this supports the model of an explosion
