The universe is full of black holes. These cosmic objects form when a massive star, much bigger than our Sun, collapses in on itself and dies in a spectacular supernova. The remains of this star are concentrated into a small but dense area, known as a singularity, with a very strong gravitational pull. In fact, it’s so strong that everything around it, even light, gets sucked in and cannot escape, making black holes diffi cult to detect. What astronomers haven’t yet been able to detect though, are white holes. Currently just a theoretical mathematical concept, these space objects are essentially the opposite of black holes, expelling matter and light into the universe instead of sucking it in. One theory about the formation of white holes is that they begin as their darker counterparts. Once a black hole has engulfed as much matter as it can, it may go into reverse, expelling it all back out again to become a white hole. Alternatively, some believe that white holes may be the exit of another type of space hole, the wormhole, while others have suggested that the Big Bang began as a white hole, expelling all the of elements of the universe. The fact remains though that, as yet, we have no proof of their existence. Although white holes have the potential to exist according to the theory of general relativity, it’s thought that they would simply be too unstable to last for very long.