Van Gogh's Starry Night Fall 2005 ASTR 1120-001 Homepage

syllabus | timetable | projects | homework | clicker questions | weekly summaries | review | images | text


Here, temporarily, is a pdf version of this webpage (3.5MB).

 summary Fall 2005 ASTR 1120-001 General Astronomy: Stars & Galaxies: Weekly Summaries

Week 1 (Aug 23)

Week 2 (Aug 30)

Week 3 (Sep 6)

Week 4 (Sep 13)

Week 5 (Sep 20)

Week 6 (Sep 27)

Week 7 (Oct 4)

Week 8 (Oct 11)

Fall break. We needed that!

Week 9 (Oct 18)

Special Relativity

Black Holes in General Relativity

Week 10 (Oct 25)

Observational evidence for Black Holes

Week 11 (Nov 1)

History of understanding of our Galaxy, the Milky Way

  • On Tuesday there was a Fiske Planetarium show on the Milky Way. The show was mostly about the history of the discovery that the Milky Way is a galaxy of stars, and that there are many other galaxies in the Universe.

    Our Galaxy, the Milky Way

    Velocity map of carbon-monoxide in the Milky Way.

    Week 12 (Nov 8)

    Galaxies

    Dark Matter

  • At the January 1998 meeting of the American Astronomical Society, two independent groups announced that the Hubble diagram of thermonuclear supernovae at high redshift indicated that the Universe was accelerating. This implied that the Universe must be dominated by some gravitationally repulsive substance - Dark Energy. This revolution led to the "Standard Model of Cosmology", in which the mass-energy of the Universe consists of the following:

  • Dark Matter (as opposed to gravitationally repulsive Dark Energy) is unseen matter which is detected by its gravitational effects.

  • Dark Matter in spiral galaxies. The rotation of the galaxy reveals the total mass of gravitating matter in the galaxy. The mass of dark matter relative to luminous matter grows more and more at greater distances from the center of the galaxy.

  • Dark Matter in elliptical galaxies. The temperature of x-ray emitting hot gas reveals the depth of the gravitational potential well, hence the total mass of gravitating matter. Typically the total mass is ten times the luminous mass.

  • Dark Matter in the Local Group of galaxies.

  • Dark Matter in clusters of galaxies.

  • What is the nature of the Dark Matter? The observations mentioned above give little clue. It could be anything dark: aliens, planets, black holes, or some mysterious particle that has never been seen in the lab.

    Cosmic Microwave Background

  • The Cosmic Microwave Background (CMB) is the radiation remnant of the primeval hot Big Bang fireball.
  • Observationally, the Cosmic Microwave Background:
  • Theoretically, the Cosmic Microwave Background:

  • Schematic evolution of the Universe

  • The Isotropy Problem: How can tiny fluctuations in the CMB grow by gravity into the observed pattern of clustered galaxies in "only" the age of the Universe?

    Week 13 (Nov 22)

  • On Tuesday there was a Fiske Planetarium show on the Big Bang.

    Thanksgiving

    Week 14 (Nov 29)

    Cosmology

    Inflation


     Van Gogh's Starry Night Fall 2005 ASTR 1120-001 Homepage

    syllabus | timetable | projects | homework | clicker questions | weekly summaries | review | images | text

    Updated 2005 Dec 1