redshift hubble’s law. redshift - absorption spectra
TRANSCRIPT
Redshift
Hubble’s Law
Redshift - absorption spectra
Plot of intensity
From doppler effect
From triangulation of movement of Earth
Increase in distance over time
AB
C
3 Galaxies A,B & C
AB
C
After time t
A
B
C
A
B
C
AB
C
Distance travelled
= H0d where Ho = 2·4 × 10−18 s−1
1Parsec = 3.262 light years
Edwin Hubble
Three astrophysicists are discussing the results of observations that show that all stars have their light
frequencies decreased by a small amount – ‘red shift’
• Professor Bubble “The red shift shows the stars are all moving away from our stationary Solar System”
• Doctor Toil “The red shift shows that we are moving away from the rest of the universe at high speed”
• Professor Trouble “The red shift shows the stars are moving away from each other”
• Which viewpoint do you agree with and why?• Why do you disagree with the other two or do
you think no one is correct?• What additional data from observations of
starlight would allow confirmation?
• Professor Bubble “The red shift shows the stars are all moving away from our stationary Solar System”
• Doctor Toil “The red shift shows that we are moving away from the rest of the universe at high speed”
• Professor Trouble “The red shift shows the stars are moving away from each other”