Edward W. Kolb, Arthur Holly Compton Distinguished Service Professor, University of Chicago. Ninety-five percent of the universe is missing! Astronomical observations suggest that most of the mass of
the universe is in a mysterious form called "dark matter" and most of the energy in the universe is in an even more mysterious form called "dark energy." Unlocking the secrets of dark matter and dark
energy will illuminate the nature of space and time and connect the quantum world with the cosmos. http://physics.oregonstate.edu/files/Yunker-2008.pdf