20. The origin of the Universe
20.1. Cosmology
20.1.1 What is the Cosmological Principle?
20.1.2 Why is the sky dark? What does that tell us?
20.1.3 What is Hubble's Law?
20.1.3.1 How does it relate to the age of the Universe?
20.1.3.2 How does it explain why the sky is dark?
20.1.4 What is the cosmic microwave background? What does it tell us?
20.1.4 What is a closed Universe? An open one? What is critical density?
20.2. Stages in the development of the Universe
20.2.1 Big Bang
20.2.2 Planck Era, GUT Era - what happened?
20.2.1 Unification of forces
20.2.2 Horizon problem
20.2.3 Flatness problem
20.2.4 Inflation and how it solves the horizon and flatness problems
20.3 Electroweak, Particle Eras -- what happened in them?
20.4 Era of Nucleosynthesis
20.4.1 Formation of helium, lithium
20.4.2 What was left over, and how much of the total mass it accounts for
20.5 Era of Nuclei
20.5.1 "Recombination"
20.5.2 Source of the cosmic microwave "3 degree" background
20.5.3 What we learn from structures on the cosmic background
20.6 Eras of Atoms, Galaxies
20.6.1 How do galaxies grow?
20.6.2 How dark matter increases the rate of galaxy collisions
20.7 The Role of the James Webb Space Telecope
20.7.1 What is this telescope designed to do?
20.7.2 Role of JWST in finding the first galaxies
20.7.3 Role of JWST in studying the assembly of galaxies
20.7.4 Other Science Programs that will use JWST
21.1 Evidence for planets around stars other than the sun
21.2.1 How can we detect planets by measuring stellar Doppler shifts?
21.2.2 What other means do we have to detect, or at least infer the existence, of planets around other stars?
21.3. Overview of exoplanet properties
21.3.1 How do exoplanets compare with planets in the Solar System?
21.3.2. Exosolar systems and typical exoplanet orbits
21.3.3. Is our inventory of exoplanets biased by how we have search for them?
22. Conditions for life
22.1 Long term climate
22.1.1 Size of variations in output of the sun
22.1.2 Solar cycle and climate
22.1.3 How we measure temperature for millions of years ago
22.1.4 Greenhouse effects and climate changes
22.1.5 Causes and effects of changes orbital geometry and tilt affecting the severity of the seasons
22.1.6 Other effects on the climate
22.2 Habitable zones
22.2.1 What is a "habitable zone"
22.2.2 List the most important conditions required to make life as we know it possible (11 of them)
23. Is life "out there"?
23.1 How life formed on Earth
23.1.1 Earliest forms of life
23.1.1.1 When did life first appear (that we have evidence for)
23.1.1.2 What form was the earliest life we know about?
23.1.1.3 What are the four key steps in getting to early life as we know it?
23.1.1.4 What role do errors in making copies play in forming life?
23.2 Life on Mars
23.2.1 Have we found evidence for life on Mars?
23.2.2 Why will we continue to look for it?
23.3 Advanced life
23.3.1 How long did take to get to cells without nuclei to cells with nuclei?
23.3.2 What was the Cambrian Explosion? How long from cells with nuclei to it?
23.3.3 How does sex assist in the development of complex life forms?
23.4 Mass extinctions
23.4.1 What role does chaos play in asteroid bombardment of the earth?
23.4.2 How is destruction spread over the Earth after a large impact?
23.4.3 Have we seen anything similar to the events leading to mass extinction on other planets?
23.5 Emergence of intelligent life
23.5.1 What is convergent evolution?
23.5.2 What is the encephalization level?
23.5.3 How has the encephalization level of the most "brainy" animals changed over the history of life on earth
23.5.4 Can we expect a similar pattern wherever complex life exists?
23.6 Contacting other civilizations
23.6.1 Why it is difficult to visit others
23.6.2 The Drake Equation, what (if anything) it tells us
23.6.3 Why we look for signs of radio transmissions by other civilizations