White Holes
White holes are the opposite of black holes. They are constantly spewing out material, but don't let anything in. White holes have properties which consist of mass, charge, and angular momentum. While we are not positive that white holes actually exist, the theory has a high chance of being correct. The possibility of the existence of white holes was presented by I. Novikov in 1964, and they were thought to be on the other side of black holes. Some think that the Big Bang was a white hole.