Last night I heard a lecture by Dr Stacy McGaugh at the Cleveland Museum of Natural History. The talk was titled Light in the Darkness: The Role of Mass, Energy and Gravity in Modern Cosmology. I doubt I could describe it better than they:
"We live in a vast, expanding Universe full of luminous wonders like stars, galaxies and quasars. These beacons of light are thought to be but a small part of a cosmos dominated by dark matter and dark energy. Stacy McGaugh describes why we think these invisible components are necessary, and examines the possibility that they may instead point to the need to extend Einstein's theory of gravity."
It was enjoyable to hear that there is still contention and disagreement in cosmology. I also enjoyed all the Calvin and Hobbes cartoons.