PH 104 – Study Guide for Exam1 (Saturday 4/28/12)

As you prepared for test1, insure you are able to answer the following questions or terminologies.

Definitions (for historical figures list their major accomplishments)

Scientific NotationLight YearConstellations

Winter/summer solsticeVernal/autumnal equinox Ecliptic

Circumpolar starsRetrograde motionEpicycle

PtolemyNicolaus CopernicusCopernican principle

Johannes KeplerSemi-major axisAstronomical unit

Galileo GalileiIsaac Newton Force

MomentumKinetic energyPotential energy

Angular momentumFrequencyWavelength

Electromagnetic radiationEmission lineAbsorption line

Blackbody RadiationWein’s LawKelvin Temperature

Kirchhoff’s lawsmassWeight

Energy levelPhotonDoppler effect

CCD PixelKeck Telescopes

VLAHubble Space TelescopeChandra Telescope

Spitzer Telescope

Comparative PlanetologyNebular HypothesisTerrestrial planets

Jovian planetsKuiper BeltGreenhouse effect

AsteroidCometMeteor

Astronomical UnitOrbital PeriodDensity

What is a scientific model, and what model do astronomers use to describe the overall properties of the universe?

  1. Describe the essential aspects of a scientific model and evaluate models in the context of scientific model making.
  2. Describe the overall properties of the universe and the three types of objects in it.
  3. Describe the scale of distances and sizes in the universe, and give several examples.

What is energy and how do astronomers use motion and gravity to understand the universe?

  1. How is mass different from weight
  2. Where do objects get their energy?
  3. What determines the strength of gravity?
  4. What is heliocentric and geocentric cosmology?
  5. What are orbits and how do energy and gravity define them?
  6. State Kepler’s laws and the implication to each.
  7. Explain how you would determine mass of the sun.
  8. What is escape speed?

What is light, how do atoms produce light, and what does light reveal about astronomical bodies?

  1. Describe the structure of a typical atom, and explain the rules which govern electron orbits.
  2. What is the difference between temperature and heat (energy)?
  3. Define what light is and what the measurable properties of a light wave are.
  4. Briefly describe the electromagnetic spectrum with examples from each major region.
  5. Describe the effect of the atmosphere on astronomical observations in the various spectral regions.
  6. Describe the differences in the appearance of continuous, absorption, and emission spectra as seen through a spectroscope.
  7. Explain how an understanding of spectra made it possible for astronomers to determine the chemical compositions of stars and the physical conditions inside their atmospheres.
  8. Use Kirchhoff's rules to relate the three basic spectral types to the physical conditions of their production.
  9. Use an energy-level diagram to explain in general how atoms absorb and emit light.
  10. Explain in simple physical terms how absorption lines occur in spectra.
  11. Identify the two most abundant elements in stars.
  12. Describe black body radiation and explain how it can be used to find the temperature of a glowing object.
  13. Explain the Doppler effect and show how it can be used to measure the velocity of an object.

How have telescopes and detectors changed the way astronomers study celestial bodies?

  1. Outline the main functions of a telescope (light-gathering, resolving, and magnifying power).
  2. Compare and contrast reflecting and refracting telescopes; include a sketch of the optical layout of each in our comparison.
  3. Compare a radio telescope to an optical telescope in terms of functions, design, and use.

24. Cite a key drawback of a radio telescope compared with an optical telescope and describe how radio astronomers cope with this problem.

25. Discuss at least two advantages a space telescope has over a ground-based telescope. What is their big disadvantage?

26. Explain how adaptive optics works, and how it has changed ground-based astronomy?

27. Explain how electronic detectors have revolutionized astronomy in the past decade.

Appearance & Motion of Sky

  1. Will the full moon be visible shortly after sunset on a clear night? Where will it be? Explain why?
  2. Explain why a first quarter moon sets approximately six hours after sunset.
  3. Describe a simple observation which demonstrates why shadows of Earth cannot cause the phases of the Moon. In general terms, what does cause the phases of the Moon?
  4. Explain why the position of the stars in the early evening sky changes with the seasons
  5. Describe the apparent motion of the stars in our sky during one night. Why do they appear to move?
  6. Explain why the position of the planets can not be easily predicted for the future. Why are their positions confined to a narrow band of the sky?
  7. Why does the Moon change shape in our sky during the course of a month?A few days after new moon, we see a thin crescent moon. When will it be visible?
  8. If a particular star is seen straight overhead in the evening tonight, where will it be in the evening sky in 6 months? In one year? Explain why.

Solar system questions (this part will not be on your exam this coming Saturday)

  1. What are the properties which distinguish the inner planets from the outer planets?
  2. What are the systematic properties of the solar system?
  3. How is the solar system organized? That is, what general properties does it have?
  4. Describe the exceptions to the pattern of systematic motion in the solar system.
  5. How is the term "solar system" defined? What sorts of objects exist in the solar system?
  6. Compare the properties of the terrestrial and giant planets.
  7. Define and explain the concepts of density and temperature.
  8. Define the term "solar system". How is it different from the universe?
  9. In general, how can we tell if a newly discovered object is a part of the solar system?

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