Lecture 20: Dark Matter (ASTR 160)
This lecture explores the cosmological scale factor, the empirical evidence for dark matter, and the discovery of dark energy's repulsive force. It concludes with a discussion of Einstein's initial conception and later rejection of the cosmological constant.
Frontiers/Controversies in Astrophysics (ASTR 160)
This lecture introduces an important concept related to the past and future of the universe: the Scale factor, which is a function of time. With reference to a graph whose coordinates are the Scale factor and time, the problem of dark matter is addressed again. Cosmological redshifts are measured to determine the scale of the universe. The discovery of the repulsive, anti-gravitational force of dark energy is explained. The lecture concludes with discussion of Einstein's biggest mistake: the invention of the cosmological constant to balance gravity.
Lecture 19: Omega and the End of the Universe (ASTR 160)
Next · Lecture 21Lecture 21: Dark Energy and the Accelerating Universe and the Big Rip (ASTR 160)