General Astronomy -
Spring
2013
Homework #12 - due April 24
1. (3 pt) When the Universe was 0.1 seconds
old, there were no
protons.
Explain why.
2. (3 pt) How
were the photons in cosmic microwave background produced?
3. (4 pt) There
is a 500 pc long ruler located 1 Gpc from Earth. You measure
the
angular size of the ruler to be 0.15 arcseconds. What does
that
imply about the geometry of the Universe?
4. (3 pt)
How can dark energy be distinguished from normal matter and
energy?