The Nobel Prize for physics was awarded on Tuesday to three scientists for their discovery that the universe in is being blown apart by a force known as “dark energy.” Saul Perlmutter of the Lawrence Berkeley National Laboratory, Brian P. Schmidt of the Australian National University, and Adam G. Riess of the Space Telescope Science Institute at Johns Hopkins University will share the honor. Adam G. Riess  discusses the honor and explains what dark energy is, and why it’s important to the universe.