Fall 2000 ASTR 1120-001 Quiz 6

Choose the single best answer and enter it on your scantron form. Be sure to fill in your name and student number.

  1. Which of the following is the single most important evidence in favor of the Cosmological Principle:
    (a) the Hubble diagram, showing the expansion of the Universe; (b) the predictions of General Relativity; (c) the Planck spectrum of the Cosmic Microwave Background (CMB); (d) the uniform large scale distribution of galaxies in the Universe; (e) the uniformity of the CMB.

  2. The spatial center of the Universe is thought to be:
    (a) you; (b) the Sun; (c) in the direction of Sagittarius; (d) M87 at the center of the Virgo cluster; (e) nowhere.

  3. The Cosmic Scale Factor is:
    (a) about 15 gigalightyears; (b) the ratio of the actual density of the Universe to the critical density; (c) another name for the Hubble constant; (d) a measure of the size of the Universe, which expands with the Universe; (e) the distance to the horizon of the Universe.

  4. Which of the Universes in the diagram at right probably describes ours?
    (e) Cosmologists still have little clue which is true.

  5. In January 1998, the Hubble diagram of high redshift supernovae revealed the unexpected and revolutionary phenomenon that the Universe is:
    (a) expanding; (b) accelerating; (c) closed; (d) flat; (e) open.

  6. In April 2000, balloon observations of the CMB with Boomerang revealed with unprecedented precision that the Universe is:
    (a) expanding; (b) accelerating; (c) closed; (d) flat; (e) open. Boomerang image of CMB

  7. In the Boomerang image of the CMB at right, the size of the blobs is roughly the size of:
    (a) a star-forming region; (b) a galaxy; (c) a supercluster of galaxies; (d) the horizon at Recombination; (e) the current horizon distance.

  8. Which of the following statements about the epoch of Recombination is false:
    (a) the expansion of the Universe began at that time; (b) the temperature then was about 3,000 K; (c) protons and electrons combined into neutral atoms; (d) the Universe became transparent to electromagnetic radiation; (e) the CMB comes to us from that time.

  9. Which of the following statements about the CMB is false:
    (a) it was discovered by Arno Penzias and Robert Wilson working at Bell Labs in 1964; (b) it has a Planck spectrum to exquisite accuracy; (c) after correcting for our motion through it, the CMB is isotropic to a few × 10-5; (d) the CMB was emitted at our horizon; (e) it is one of the main evidences in favor of the hot Big Bang.

    COBE image of CMB

  10. In the COBE image of the CMB at right, the `dipole' pattern is caused by:
    (a) microwave radiation from Earth; (b) microwave radiation from the Milky Way; (c) temperature fluctuations in the CMB; (d) the Planck spectrum of the CMB; (e) motion of the Solar System through the CMB.