. The Universe is expanding. What is the evidence we have for this (make sure you state how this evidence implies that the Universe is expanding)? What exactly is it that is expanding (for instance, does matter take up more room)? How does this relate to other observations such as the fact that the sky is dark at night and the discovery of the Cosmic Microwave Background radiation? This question is worth 30 points.
Q2. Explain how our current understanding of the formation of the solar system can account for the following characteristics: This question is worth 30 points.
A. All planetary orbits lie in nearly the same plane.
B. All planetary orbits are nearly circular.
C. The planets orbit the Sun in the same direction that the Sun itself rotates.
Q3. Intermediate and high mass stars fuse hydrogen into helium using the CNO-cycle, while low mass stars use the proton-proton chain. What are the main characteristics of the two cycles, and given that the CNO-cycle is much more efficient at fusing hydrogen than the proton-proton cycle, why do low mass stars not utilize the CNO-cycle?