We all know that black holes can collide. It has happened since black holes began to form, early in cosmic time. The result is always a clash that gives off gravitational waves and a giant bang. Since black holes have such strong gravity, it's almost impossible to imagine a way that any force could break one apart. Yet, that's the task that a group of scientists in Europe set for themselves.

In a study of possible mechanisms for black hole fragmentation, Francesco Sannino of the University of Naples Federico II in Italy and the Quantum Field Theory Center at the University of Southern Denmark, along with Giacomo Cacciapaglia (Laboratoire de Physique Théorique et Hautes Énergies) and Manuel Del Piano and Vania Vellucci, both from the Quantum Field Theory Center, conducted a series of calculations showing that under the right conditions, a black hole could split up into two black holes.…