Due Wednesday July 17 by 10 pm

Submit your assignment through Canvas via the HW2 link.

Most of these questions will require doing research/reading outside of the course material. That's one of the essential points of homework. Also, there is relevant material available under the resources tab on the course web site.

1. How did Einstein's new theory help to resolve the dilemma posed by discovering that the orbit of Mercury did not conform to Newton's Laws.
   
   
   
2. Suppose that I take a spectrum of two galaxies.
   
   
   • Galaxy 1 I observe that the hydrogen line has a wavelength of 8204 angstroms.
   • In Galaxy 2 I observe the hydrogen line has a wavelength of 6549 angstroms.
   
   
   I know from laboratory measurements that the rest wavelength of this hydrogen line is 6563 angstroms. Given this data, compute the radial velocity of galaxies 1 and 2 using the method described in this tutorial
   
   
3. Google (and don't be lazy and rely on the usually erroneous and incomplete Wikipedia) on "Andrew Mckellar Microwave Background". McKellar actually detected the MWB in 1941 (!) but did not realize it at that time. Speculate why you think he was unable to put his data together to claim initial discovery and hence a future Nobel prize.
   
   
4. Explain why its not possible to make elements heavier than Helium during the period of Big Bang Nucleosynthesis.
   
   
5. Explain why, in a uniformly expanding Universe, every observer would think they are in the center of that expansion.
   
   
6. What conditions produced the observed photo to baryon ratio in the current universe and why are these conditions somewhat mysterious?