The Standard Model, Dark Matter, and Dark Energy: From the Sublime to   the Ridiculous
  The Standard Model of cosmology of the 1980's was based on a remarkable interplay of ideas from particle theory, experiment and astrophysical observations. That model is now dead, and has been replaced by something far more bizarre. Interestingly, the aspect that has survived involves perhaps the most exotic component: dark matter that dominates the gravitational dynamics of all galaxies, and appears to be composed of a sea of new weakly interacting elementary particles. But this sea of dark matter appears to play second fiddle to an unknown energy density that appears to permeate all of space, causing the expansion of the Universe to accelerate. We are left with many more questions than answers, and our vision of the future of the Universe has completely changed. (Lectures Given at the XIV Canary Islands Winter School in Astrophysics 2002: Dark Matter and Dark Energy in the Universe. Nov 2002 To Appear in the Proceedings) 
Lawrence M. Krauss (Case Western Reserve University)