Homework 3, Astr305V, Fall 2018, Due date: September 25, 2018

1. Is our Solar System expanding as a result of the expansion of the Universe, or not? Explain your answer.

2. Why can we not use ¹⁴C to find the age of most of the rocks on Earth?

3. We learned from the Big Bang theory that the Universe is a little more than 3 times older than the Earth and the Sun. We also learned that the Sun has enough hydrogen in its core that it can shine for about 9 billion years before it runs out of energy. So we are about half way through. The Milky Way, like all galaxies started forming soon after the Big Bang.

Given this, consider the following statement: "It is pretty much certain that there are stars like the Sun but perhaps one or two billion years older than the Sun. If those stars have planets too, life would have had 1 to 2 billion years more time to evolve, so such planets likely would have far more advanced life than we do."

Describe if this statement makes sense to you or if you find a reason why we might not be so certain about the point that it makes.