Cosmologists have declared 96% of the universe missing. Two mysterious things, dark matter (http://en.wikipedia.org/wiki/Dark_matter)and dark energy (http://en.wikipedia.org/wiki/Dark_energy), make up most of what cosmologists believe to be the cosmos. Neither can be seen, leaving 4% consists of things we are familiar with, dirt, stones, water, and stars. On this show, Richard Panek, author of, The 4% Universe: Dark Matter, Dark Energy and the Race to Find the Rest of Reality (http://www.amazon.com/The-Percent-Universe-Discover-Reality/dp/B007K4QADA), joins Philip Mereton in a conversation about how the search for the missing pieces to the universe has become the number one quest in cosmology.