Scientists have come up with a new theory about how ultra-light black holes could be formed, and it's an entirely new way of looking at the phenomenon. Some black holes might be formed from the outside in, not the inside out.
Traditional black holes are formed one basic way. An object in the universe, usually a large star, becomes so big and so dense that its own gravity causes it to collapse in on itself. It sucks itself into a single point in space. (Black holes look so large because the force of gravity near them is so strong that not even light can escape, leading to a large black section of the universe delineating the edges of the highest-gravity area.) Since it took a certain amount of mass to collapse matter so entirely, black holes were thought to be super-massive objects. The lightest of them would have to have a core twice the size of the earth's sun.
Some researchers have thought of a new way of making black holes; one that allows for very light objects to make them. Instead of an object being sucked into itself by its own gravity, it could be crushed down by outside forces. Scientists believe that a 'dwarf' black hole could form during a supernova, pushed into a singularity by the force of the blast. Such black holes could have the mass of a mere planet. These hidden pockets of high gravity could be responsible for the 'dark matter' that astronomers detect. They would exert a high gravitational pull, while being small enough to go undetected.
Image Credit: Nasa-JPL
Via New Scientist.