WHAT'S DARK ENERGY?

                               WHAT'S DARK ENERGY? 

 Scientists have given the name dark energy to the expansion-generating force or substance of the universe. Dark energy is the reverse of gravity: It pushes things away rather than pulling the together. It is unknown whether the laws of physics or the general theory of relativity can account for dark energy. In 1998 astronomers studying supernovae found them dimmer than anticipated. This meant both they were farther away and the universe was expanding faster than expected.The U.S. government's Joint Dark Energy Mission (JDEM) examined Type la supernovae, dying white dwarfs, because of their high and consistent luminosity. Theprogramended in 2010, and will be replaced  by the Wide-Field Infrared Survey Telescope (WFIRST).