https://www.vice.com/en_us/article/9kepy8/watch-this-ultra-hypnotic-supercomputer-simulation-of-galaxies-feasting > Galaxies are ravenous eaters. In addition to occasionally cannibalizing each other, galaxies are constantly feeding on gases strewn across the vast spaces that separate them. > These gases spill into the intergalactic medium when stars explode into supernovae, and are subsequently recycled when they are sucked back into galaxies to fuel the formation of new stars.