2. If the sequence above represents a range of stars that are close to us ( ) and at increasingly far distances, how do we interpret the changing positions of the emission lines? 1.The energy levels in the individual atoms are changing. 2. All these stars have different compositions 3. The lines started out at the same wavelengths, but something shifted them on their way to Earth. 4. Aliens are messing with our minds.

4. What causes light from a star to be Doppler- shifted? 1) the distance between us and the star 2) the gas and dust between us and the star 3) the speed of the star toward or away from us 4) temperature differences between us and the star

6. If the universe is expanding, won't the Solar System eventually expand apart? 1) The Solar System may actually be shrinking now, which makes the universe LOOK like it's expanding. 2) No, its gravity holds it together 3) No, because there is no planetary redshift. 4) Eventually, but only after a very long time.

8. The blueshift exhibited by some nearby external galaxies lends support to the: 1) Big Bang model, because those galaxies are expanding towards us. 2) Local Group concept, because nearby galaxies interact gravitationally 3) evolution theory, because galaxies change color as they evolve. 4) oscillating universe theory, because some galaxies are moving together already.

9. The Hubble Age of the universe, 1/H, represents how long ago the Big Bang happened, based on its current rate of expansion. The Hubble Age must 1) ignore the gravitational interaction of matter 2) be a maximum possible age. 3) be a minimum possible age

10. The Hubble Age of the universe, 1/H, represents how long ago the Big Bang happened, based on its current rate of expansion. The Hubble Age must 1) ignore the gravitational interaction of matter 2) be a maximum possible age. 3) be a minimum possible age

11. If the Big Bang cosmology is correct, then 1) the most distant galaxies we observe are seen now as they will be in the future. 2) nearby galaxies are seen at a more advanced stage of evolution than distant galaxies 3) matter is being continually created. 4) the universal expansion must be slowing down.