Exam #3 is today, in the classroom.

  • How do we know the Universe is expanding?
  • What determines if the Universe is open or closed?
  • Give an example of a baryonic dark matter candidate and a non-baryonic candidate.
  • Give an example of how changing a physical constant would prevent the development of life.
  • What is the cosmic microwave background? Where did it come from? Why is it in the microwave?
  • What is the Planck time?
  • Describe the three possible geometries of the Universe. Draw a radius-time diagram to describe the fate of these three geometries. What are the two cosmological constants. How does one of them determine which geometry of the Universe we are in?
  • How do we know that dark matter exists? Describe two observations that demonstrate that dark matter exists.
  • Describe Olber's Paradox. What does it state about the Universe?
  • What is Hubble's law? Why does this mean the Universe is expanding? Why does this support a Hot Big Bang cosmology?
  • Describe a closed Universe in terms of geometry, expansion, density and its future.
  • What is a symmetry breaking? Describe the three symmetry breaks in the early Universe in terms of what broke and what that meant.
  • How is matter made? Why should there be no matter today? In that case, why is there matter?
  • We know from the abundance of light elements that $\Omega_{baryons}$ is around 0.01. Why? We know that $\Omega_{dark matter}$ is 0.3. How? We think $\Omega_{total}$ is 1. How will we get the extra 0.7 to `flatten' the Universe?
  • Explain what is meant by curvature of the Universe. Can you have an finite, negative curvature Universe? How do $\Omega_{M}$ and $\Omega_{\Lambda}$ combine to determine curvature.
  • How do we know the Universe is filled with dark matter? How do we know that dark matter cannot be old stars, like black holes or black dwarfs? How do we know the amount of baryons is about $\Omega_{baryons}=0.02$?
  • What is symmetry breaking in the early Universe? When we state that two forces are unified, what does that mean? Draw the unification diagram for the four fundamental forces.
  • How is energy converted into quark pairs? Where are all the matter-antimatter pairs today?
  • What is the origin of the fluctuations in the CMB? How do they relate to the large scale, bubble-like structure of galaxies today?
  • How do we know we live in an expanding Universe? How does resolve Olber's Paradox?
  • What do we mean when we say the geometry of the Universe? What are the three possible geometries? How could we measure which three we live in using triangles (or parallel lines or galaxy counts)?
  • What are the three possible dynamical futures of the Universe? How does gravity and the cosmological constant determine which one we live in?
  • How do we know dark matter exists? How much of the Universe is in the form of matter (i.e. what is $\Omega_m$)? How does the abundance of light elements tells us that dark matter is not baryonic?
  • How did Hubble demonstrate that we live in an expanding Universe? Why is recessional velocity an incorrect interpretation for redshift?
  • What are the three possible dynamical futures of the Universe? How does $\Omega_M$ and $\Omega_{\Lambda}$ determine our fate?
  • Sketch the unification diagram.
  • How does the abundance of light elements tells us that dark matter is not baryonic?
  • What is the Multiverse and why do we believe we are in a bubble universe?
  • How did Hubble demonstrate that we live in an expanding Universe? Why is Doppler velocity an incorrect interpretation for redshift?
  • What is $\Omega_M$? What is its current value? Without dark energy, how does $\Omega_M$ define the future of the Universe?
  • How do we know dark matter exists? Why can it not be baryonic?
  • What is inflation? How does it resolve the horizon problem?
  • Where do the elements lighter than helium come from? Where do the elements behind helium and iron come from? Where do the elements heavier than iron come from?
  • How do we know we live in an expanding Universe? How does resolve Olber's Paradox?
  • What are the three possible geometries of the Universe? How could we measure which three we live in using triangles (or parallel lines or galaxy counts)?
  • What are the three possible dynamical futures of the Universe? How does gravity and the cosmological constant determine which one we live in? What kind of Universe do we live in?
  • How do we know dark matter exists? How much of the Universe is in the form of dark matter?
  • How are baryons made in the early Universe? (i.e. what are involved and describe the process).