red + blue shift

Question 1

redshift vs blueshift

Answer 1

redshift: spectrum shifted towards lower frequencies
blueshift: spectrum shifted towards higher frequencies

Question 2

cause of redshift

Answer 2

expansion of space
- light wave is expanded, therefore it is moving away

Question 3

cause of blueshift

Answer 3

stars moving towards earth
- light wave is compressed, therefore it is moving closer(doppler effect)
- gravity is pulling the star towards the earth faster than the space is expanding

Question 4

when does redshift increase

Answer 4

when the speed of the star increases
- the further away a galaxy is, the faster it is moving away from us

Question 5

relationship between the speed at which a galaxy moves and its distance from earth

Answer 5

v = H0d
- v = the speed of the galaxy
- d = distance from earth
- H0 = Hubble constant, approx. 70.4km/s per Mpc
- Mpc means a mega parsec, 1,000,000 parsecs

Question 6

what causes doppler lines

Answer 6

hydrogen absorption: hydrogen absorbs light, and the light on the spectrum which is absorbed by hydrogen creates the lines in which we can use to detect blueshift and redshift

Question 7

size of the doppler shift vs velocity of the star

Answer 7

linear relationship, shown by Hubble Diagram