ASTRO 142 Lecture Notes - Lecture 9: Cosmic Distance Ladder, Cosmological Constant, Observable Universe
Document Summary
Astro 142: from the big bang to the milky way. Chapter 10 discussed a variety of related phenomena including the cosmological redshift, hubble"s law, a new metric for the universe, the cosmological constant, and more. In entirety, chapter 10 discussed the expansion of the universe and its implications. As with all other chapters chapter 10 discussed its focus (the expanding universe) in the manner through which it was discovered. It begins with the discovery of redshifts of distant galaxies and the di culties earlier as- tronomers had in determining distances to them (as well as to distant stars). Of great importantce was determining the size of the milky way galaxy. Phenomena such as cephids, nova, supernova, and other standard candles (or approximate standard candles) were used to determine approximate distances to cellestial objects which were too distant to use parallax (this includes all galaxies). Determining such objects even existed was a great debacle in itself.
