Red Shift Blue Shift

What best describes the doppler effect?

• An apparent change in frequency of a wave due to the relative motion between a wave source and an observer
• When sound changes pitch
• When light changes color
• An apparent change in the amplitude of a wave due to the relative motion between a wave source and an observer.

If a star is being observed from Earth and it's light has shifted towards the blue side of the electromagnetic spectrum it would be...

• Moving towards the Earth
• Moving away from the Earth
• This is a trick question that cannot be answered
• It isn't a star, it is a very large blueberry.

The vast majority of galaxies in our universe are moving away from us.  We know this because we observe __________ in the galaxies absorption spectra.

• Redshift
• Blueshift
• Turbulance
• Superposition

Use the image to identify the motion of the object relative to Earth.  Compare the absorption spectra of the star to what the star would look like if it were not moving at all relative to Earth.

• It is not moving
• It is moving away from Earth (Redshift)
• It is moving towards Earth (Blueshift)
• It is moving towards Earth (Redshift)

Are any of the galaxies moving towards Earth?  Explain.

• A.  It is redshifted
• B. It is redshifted.
• C. It is blue shifted.
• A. It is blueshifted.

Based on  Doppler effect, which of the galaxies is moving away from Earth?

• A
• B 
• C
• A and B

The picture below represents the line spectrum of hydrogen

Which of the following represents the spectrum of Hydrogen from a source moving away rapidly?

• 
• A

• B

• C

• D

What does the Red-shift tell us about the universe

• the universe is expanding
• the universe is contracting
• the big bang is false
• nothing