what is a black hole and why are they important?
<answer> A black hole is a region in space where the pulling force of gravity is so strong that light is not able to escape. As a pair of black holes spirals around one another, they can spin in the same direction or they can be completely different. <context> As a pair of black holes spirals around one another, they can spin in the same direction or they can be completely different. This is the first time that we have evidence that the black holes may not be aligned, giving us just a tiny hint that binary black holes may form in dense stellar clusters, said LIGO researcher Bangalore Sathyaprakash of Penn State and Cardiff University.