Version: 2 March 2012 @ 5:20 am. This page will be updated this weekend and after Tuesday's class.
Version: 2 March 2012 @ 11:47 am. Added old Test 2 and additional questions to last section
Version: 6 March 2012 @ 2:27 am. Added old Final

Test 3, March 8, 2012
Astronomy 123

Material: Topic 6, History of the Universe (Chapters 26 and 27), Topic7: Observations and the Fate of the Universe (Chapters 24-26); consider material covered in Homework 5, and other information covered in lecture (not covered in the web notes because of their topical nature) such as the current events and recent results sometimes looked at the beginning of class. There was an interesting article we found and brought up in class the last week or so.

I am still searching for an old exam to post. For now, let me repost Test 2 from last fall. There is relevant information on this exam.

Test 2

I placed the old final from last fall here. There is relevant information on this exam.

Final

The above exams are meant to show typical questions (which could appear on Test 3) and are not meant to be exhaustive in coverage. Also note that only selected questions are relevant, your notes will allow you to determine which cover questions cover the material covered during the last 2-3 weeks of class.

General Thoughts on "Problems"

Describe the Horizon Problem. Include the observations upon which the problem" is based, include why the observation leads to the "problem."
Describe the Flatness Problem. Include the observations upon which the problem" is based, include why the observation leads to the "problem."
Describe the Anti-Matter/Matter Asymmetry Problem. Include the observations upon which the problem" is based, include why the observation leads to the "problem."
Describe the Cosmological Constant Problem. Include the observations upon which the problem" is based, include why the observation leads to the "problem."

Dark Energy and Anti-Matter: What is anti-matter? How do the properties of the anti-matter electron, the position, differ from the matter electron? A recent suggestion is that anti-matter behaves like negative mass. Is this accepted by most physicists and astronomers? How would this suggestion (if shown to be true) for anti-matter help us to understand dark energy and how could it affect the solution for the anti-matter/matter asymmetry problem?
History of the Universe

Describe and outline the general history for the evolution of the Universe.

List the phases in the evolution of the Universe
Give the time at which the phases set in
Give the basic events which occur during the phases
What (events) mark the transitions between the phases

What are the four known forces of the current Universe? Have there always been only four distinct forces (four distinct ways in which things interact) in the Universe? If not, how has the situation evolved?
What forces play dominant roles in the evolution of the Universe? How does the changing number of forces as the Universe evolves lead to inflation?
What is meant by the terms GUT and Planck era?
Describe Inflation. Describe how inflation is related to GUTs. How can we understand inflation through analogy with ordinary phase transitions such as occur for water as it goes from liquid to solid (ice), liquid to gas (evaportation), solid to gas (sublimation) as the temperature is changed. Be sure to include the importance of supercooling.
Describe the mysteries of the Universe Inflation solves and explain how Inflation solves them.

How old is the Universe? How do we arrive at this age estimate? How old are the oldest stars in the Milky Way galaxy? Is there a problem with this age for the oldest stars?
Sketch the scale factor, R(t), for a universe with a constant expansion rate. Sketch R(t) for a closed universe, an open universe, and a flat universe. Explain why the age estimated for the universe under the assumption that the expansion rate is unchanging is an overestimate for the age of the universe if the actual expansion rate for the universe is getting smaller (that is, for a "slowing" universe).
What is the correct order for the radiation era, the matter era, and the dark energy era? When and why did the transitions from era to era occur? (What is meant by radiation era, matter era, and dark energy era?)
Describe how the Universe evolved starting from the Planck Era (what is meant by the Planck Era) to the GUTs to the Quark Era to Nuclear (Nucleosynthesis) Era and to the formation of the CMBR.
Big Bang Nucleosynthesis. When were the chemical elements present in the Universe formed? Why were they not formed earlier (what is the deuterium bottleneck?) What chemical elements were produced in the Big Bang? Why weren't elements like carbon, nitrogen, and oxygen produced in the Big Bang? What is the significance of the detection of deuterium?
What is meant by symmetry breaking? What were the various symmetry breakings which occurred in the evolution of the Universe?
What are quarks, gluons, leptons, and neutrinos? What are the fundamental particles? Whyd did the quark era end? What are the baryons? When did baryons come into existence? What is baryogenesis? When did pair production of baryons end? Why did pair production of baryons end?
What is Recombination? When did it occur? What are the consequences of recombination? What does it have to do with the CMBR?

Describe the connection between observations of the temperature fluctuations in the CMBR and the observed structures in the Universe, and then describe how these observations lead to constraints on dark matter.
What is meant by pair production? What is meant by annihilation? Physicaly, what is the meaning of E = mc²? How do these notions lead to conundrum of the the Matter/Anti-Matter Asymmetry?
What are virtual pairs? What is the Heisenberg Uncertainty Principle? How does the notion of the Heisenberg Uncertainty Principle lead to virtual pairs.
Cosmological Constant. How do virtual pairs lead to a possible explantion for the Cosmological Constant? How does a matter particle differ from its anti-matter twin? We say that the Cosmological Constant corresponds to negative pressure. Explain this comment. What is the cosmological constant problem?

The Ulimate Fate for the Universe: Methods Used to Determine the Fate

Describe how the following methods used to determine the ultimate fate of the Universe work:

Comparison of the mass of the Universe to the escape speed of the Universe. What is the result of these studies? How does it compare to the following two studies? What objects and observations allow us to determine the mass of the Univese? That is, what are the various ways in which we can estimate masses in the Universe? What observations are made to determine the expansion rate of the Universe? Based on observations, roughly how old is the Universe? Explain how this estimate depends on the particular model for the Universe (we assume to be correct). (Show how scale factor R(t) plots demonstrate these effects.)
Examination of the behavior of the Hubble Law at large z. How is the Hubble Law at large z determined? Which standard candle is used in this exercise? What is the fate of the Universe implied by these results? Sketch the Hubble relation and its behavior for large redshift z. How did we infer that dark energy dominates the evolution of the Universe at the present time based on these observations?
Comparison of the models of the Universe to the CMBR. How did WMAP use the small fluctuations in the CMBR to determine the dark matter content of the Universe? What is the dopole anisotropy? (by the way, what WMAP stand for?) What does the CMBR say about the efficacy of inflation as a model for the early expansion of the Universe? Describe the basic results of the analysis of the CMBR data obtained by WMAP.

What is current best model for the Universe? What is the Universe composed of for the best model? Cite the evidence that leads to our current best model for the Universe?
Carefully, distinguish between Dark Matter, Normal Dark Matter, Exotic Dark Matter, Dark Energy, Quintessence, Cosmological Constant
What is meant by the term critical density? How much mass (in terms of the critical density) is found in the mass studies of the Universe? How are these results reconsiled with the fact that there is strong evidence (from other methods [which mehthods]) which imply that the Universe is flat, that is, the Universe has the critical density?