Astronomy 100, Unit 1 Homework

  1. What was Johanne Kepler's biggest contribution to astronomy?
    a. He combined the Copernican and Ptolemaic models, keeping the best parts of each.
    b. He improved the geocentric model of Ptolemy by adding additional cycles.
    c. He improved the heliocentric model of Copernicus by changing the circles to ellipses.
    d. He completed the model that Tycho Brahe had started to develop.
  2. What sort of instrument did Tycho Brahe use to measure the position of Mars?
    a. a telescope.
    b. a spectroscope.
    c. a quadrant.
    d. an orrery.
  3. Who used mirrors to invent the reflecting telescope?
    a. Galileo Galilee.
    b. Johanne Kepler
    c. Edmund Halley.
    d. Isaac Newton.
  4. Who is given credit for using lenses to invent the refracting telescope?
    a. Galileo Galilee.
    b. Nicholas Copernicus.
    c. Johanne Kepler.
    d. Hans Lippershey.
  5. How did the Ptolemy explain the apparent retrograde motion of the planets?
    a. He held that the planets moved along small circles that moved on larger circles around the Sun.
    b. He held that sometimes the planets moved backward along their circular orbits.
    c. He varied the motion of the celestial sphere so that it sometimes moved backward.
    d. He held that the planets moved along small circles that moved on larger circles around the Earth.
  6. Which of the following statements about electrons is true?
    a. Within an atom, an electron can have only certain specific amounts of energy
    b. Electrons have very high mass compared with protons or neutrons.
    c. An electron has a positive electrical charge.
    d. Electrons can jump to a higher energy level in an atom only if they emit the energy difference in the levels.
  7. Which of these allows an electron in an atom to go from a lower energy level to a higher energy level?
    a. It releases a photon with energy equal to the atom's energy drop.
    b. It absorbs a photon with energy equal to the atom's energy gain.
    c. It loses gravitational potential energy.
    d. It exchanges gravitational potential energy for kinetic energy.
  8. Why are the phases of Venus, first observed by Galileo, at odds with the geocentric model?
    a. Venus would not be expected to change size in the geocentric model.
    b. Venus does not exhibit phases, thus disproving the geocentric model.
    c. Venus would never appear in the morning sky in the geocentric model.
    d. Venus would never appear in the evening sky in the geocentric model.
  9. According to Kepler's Laws, what is the shape of an orbit?
    a. An ellipse.
    b. A circle.
    c. A hyperbolic paraboloid.
    d. A Fibonacci spiral.
  10. Which of the following is untrue?
    a. Tycho Brahe had a pet elk that died when it got drunk and fell down the stairs at a party.
    b. Tycho Brahe had a false nose because he lost his in a drunken knife fight at a party.
    c. Tycho Brahe died under mysterious circumstances while drunk at a party.
    d. Tycho Brahe didn't like to party.
  11. According to the inverse square law of light, if you double your distance to a source, the brightness will...
    a. decrease by a factor of 3.
    b. decrease by a factor of 4.
    c. decrease by a factor of 5.
    d. decrease by a factor of 6.
  12. Which is the best summarized implication of Galileo's research?
    a. It challenged the traditional cosmology of the power elite.
    b. It challenged the classical models of physics.
    c. It challenged the authoritarian acceptance of knowledge.
    d. All of the above.
  13. Gas that is millions of degrees has a peak output of ...
    a. equal amount of all frequencies of light.
    b. radio waves.
    c. visible colors.
    d. x-rays.
  14. What is Edmund Halley NOT famous for?
    a. Predicting the return of a comet.
    b. Measuring the speed of light.
    c. Charting the tradewinds.
    d. Inventing the diving bell.
  15. Which of these accurately describes Claudius Ptolemy?
    a. The writings of Ptolemy include names and outlines of all 88 constellations still in use today.
    b. Ptolemy was an influential astronomer, geographer, and mathematician living in ancient Babylon.
    c. He promoted the heliocentric idea that the Sun was the center of the Universe.
    d. His cosmic model prevailed in Europe for the next 1400 years.
  16. Which of the following statements about X-rays and radio waves is true?
    a. X-rays have lower frequency than radio waves.
    b. X-rays and radio waves are both forms of light, or electromagnetic radiation.
    c. X-rays have longer wavelengths than radio waves.
    d. Neither X-rays nor radio waves can penetrate the Earth’s atmosphere to reach the surface.
  17. If you heat a low-density gas so that collisions are continually bumping electrons to higher energy levels, when the electrons fall back to lower energy levels the gas produces
    a. thermal (black-body) radiation.
    b. infrared light only.
    c. an absorption line spectrum.
    d. an emission line spectrum.
  18. Suppose you see a blue star and a red star through binoculars. What can you conclude?
    a. The red star is more massive than the blue star.
    b. The red star has a higher surface temperature than the blue star.
    c. The blue star is more massive than the red star.
    d. The blue star has a higher surface temperature than the red star.
  19. What causes the aurora?
    a. Geomagnetism energizes atoms in the upper atmosphere near the poles of the earth..
    b. Particles from the sun energize atoms in the upper atmosphere near the poles of the earth.
    c. Thermal currents energize atoms in the upper atmosphere near the poles of the earth.
    d. Plate tectonics energize atoms in the upper atmosphere near the poles of the earth.
  20. What great astronomical discoveries did Galileo make with a telelscope?
    a. Jupiter has moons.
    b. Venus goes through phases.
    c. The hazy path of the Milky Way is made of stars.
    d. All of the above.