The discovery of accelerating expansion: Panek 2011, Kirshner 2002, Livio 2000, and Goldsmith 2000 provide colorful popular accounts of the discovery.

Type 1a supernovae are very rare: They are thought to result from white dwarfs that accrete mass up to the maximum mass allowed for a white dwarf (the Chandrasekhar mass). At that point, they ignite carbon at their centers. The entire white dwarf is destroyed in the explosion.

combining detailed observations of the fluctuations: The website of the Wilkinson Microwave Anisotrophy Probe (WMAP) provides updated information at www.map.gsfcnasa.gov.

were hung on concepts such as supersymmetry: Kane 2000 provides a beautiful popular description of the concepts involved in supersymmetry. Dine 2007 is an excellent technical text.

The properties of our universe: In the presentation here, I largely follow the discussion in Livio and Rees 2005. A classical book on anthropic reasoning is Barrow and Tipler 1986. Vilenkin 2006, Susskind 2006, and Greene 2011 give popular, comprehensive discussions of anthropics and the multiverse concept.