Dark energy
repulsive property with constant energy density theorized to make up most of the universe’s energy content to account for its observed expansion / From Wikipedia, the free encyclopedia
Dark energy is the name given to the force that is believed to accelerate the expansion of the universe. Distant galaxies appear to be moving away from us at high speed: the idea is that the universe is getting bigger and has been since the Big Bang. Measurements are now accurate enough to allow astronomers to tell that these galaxies seem to be accelerating away from us. The universe is expanding at an increasing rate.