When wading into the murky realm of theoretical physics, one of the more difficult concepts for scientists to explain is that of dark matter. It’s the invisible form of matter constantly eluding scientific hard proof, whose existence is suggested only by the circumstantial evidence we can measure around it. It doesn't interact with light — it's literally "dark."
As mysterious as dark matter may seem, however, most scientific theories assume its ingredients are pretty basic — just one weird, lightweight particle found all over the universe, that hardly ever touches other kinds of matter. But all that may now be up for debate.
