Astro 3 - Key Themes in My Test Bank

This is a generic list. I made this by looking at all the ~ 250 questions in my test bank. Remember that I make my quizzes and finals fresh each semester, and you'll see roughly 120 questions drawn randomly from this master test bank. For more help in studying for your particular questions, refer to the study guide I handed out and which is on-line for the Monday/Wednesday, and for the Monday evening classes, which focuses in a different way on your particular exams. Looks like a lot to learn here, right? But before you get depressed, realize that your particular exams will only sample a small part of this, and all you need is a 80% for an "A". You can do it!

Chap 0: Scientific Thinking

• All of "Chap 0" is important! Read it thoroughly and ask for any clarifications
• The steps of the scientific method
• The nature and psychological issues of pseudo-science.
• Occam's Razor and Sagan's Corollary
• Modes of representing reality in our minds
• The fatal flaws with supernaturalism

Our Place in the Universe

• Most of this material we will cover in more detail later so I have not written questions on it. But, I do have a few introductory ideas for you to focus on
• Distances; definition of a light year, the general distance order of things out there; planets, stars, galaxies.
• There are 4 forces in Nature, which account for pretty much all we see so far.

Earth and Sky

• How the seasons and the sky look different at different latitudes.
• How the sun moves across our sky differently during different seasons.
• How to relate the phases of the moon and time of day to where the moon appears in the sky.
• The nature of lunar and solar eclipses; what phase they occur and the nature of the shadows involved.
• Understand the cause of retrograde motion.

Gravity, Motion, Relativity

• Know Kepler's 3 laws and their meaning
• Know Newton's 3 Laws of Motion and their meaning
• Gravity - stronger with increasing mass and with decreasing separation of the gravitating objects
• Feel the force of gravity and how it would change if you were inside a spherical distribution of mass
• Tides as more than water at the beach - the cause of tides via gravity and what aspects of a gravitating system will increase or decrease tidal force
• Spring tides and neap tides and how they relate to the position of sun, moon.
• The meaning of angular momentum and conservation of angular momentum
• (Astro 4 only) General relativity = modern gravity, paths follow curvature of space, determined by mass, energy density.

Light, Matter

• Photons as electromagnetic waves in a particle form
• The two ways to produce photons.
• The electromagnetic spectrum and the names of the different energy or wavelength bands in the spectrum. Which bands will pass through earth's atmosphere.
• The structure of the atom: nucleus and electrons in quantized orbits. Don't memorize the names of atoms and how many protons! I want concepts.
• Emission and absorption of photons via electrons changing orbits in atoms, and how these processes make the spectral "lines" in astronomical objects.
• Absorption lines: produced by cool gas in front of a hot object
• Emission lines: produced by gas lit up from the side against a black background.
• The Doppler effects; photons "redshifted" to longer wavelength if source / observer are moving apart; "blueshifted" if moving towards each other
• Know the shape of a thermal spectrum, and the two thermal radiation laws: Hotter objects are bluer. Hotter objects give off more total light.

Telescopes, Detectors

     * Large modern telescopes are all reflecting telescopes, using mirrors and not lenses

     * Imaging is done with CCD detectors - digital for astronomers

     * Only Visible and Radio bands make it through the earth's atmosphere and can be studied from ground-based telescopes

     * Light gathering is the most important property of a telescope. Size matters, big!!

Formation of the Solar System

• Know how we have detected solar systems around other stars
• The key features of our solar system any theory must explain: ~circular orbits, co-planar, revolve in same direction, same plane as sun's equator.
• Inner planets vs. outer planets general properties; rocky, thin atmosphere vs. hydrogen/helium rich giants with small rocky cores.
• The roll of tides in the formation of our solar system, and the general formation process, and age.
• The two regions of comets, Oort Cloud and Kuiper Belt and where they are
• How planets lose their initial atmosphere; the different processes that govern how a planet's atmosphere evolves.
• The age of the solar system; 4.6 billion years

The Terrestrial Worlds (Mercury, Venus, Earth, Mars, the Moon)

• The origin of planets' interior heat; kinetic energy of collisions.
• The factors which govern how rapidly a planet loses heat
• How the rate of impacts on planets has evolved since their formation
• The nature of the Greenhouse Effect
• Tectonic activity; nature and logic of why only Earth has it
• History of Martian water, magnetic field loss allowed solar wind to strip away atmosphere

Earth's Atmosphere

       * CO2 history of Earth - overall decline with geologic time. Carbonate rocks created by life pulling CO2 out of atmosphere
       * Milankovich orbital cycles and the Ice Ages
       * Modern global warming - firmly established to be caused by humans, mainly CO2 from fossil fuel burning
       * climate denialism, debunking myths

The Jovian Planets

• Why Jupiter and Saturn give off more heat than they receive
• Tidal stretching and friction and its effect on planetary moons
• Planetary rings; origin and composition

Asteroids, Comets, Meteoroids

• Relation between comets and meteor showers
• Comets; dirty snowballs and the two tails that develop
• The asteroid belt; why did it form? Where is it?
• The two regions of comets; Kuiper Belt and Oort Cloud; where they are

The Sun

• The structure of the sun; layers
• Sunspots and the sunspot cycle

• Stars - balancing gravity, energy production, pressure. How changing one will affect the structure of the star
• Aurorae; relation to the solar corona, magnetic fields

Life in the Universe

• The Miller-Urey experiment created amino acids out of the chemistry, conditions of the early Earth
• G, K main sequence stars most likely to have living planets
• Carbon - the only element permitted by the laws of physics which can be used to make complex molecules, why needed for life.
• The argument for searching for radio communications near the main spectral lines for water
• mixing dirt and organic chemicals can produce RNA, precursor to the first life?
• Know basic theory of evolution by natural selection