This questions could not be answered by current science. Could only make guesses. For first, most current answer, we just know, something exists in Universe, w

This questions could not be answered by current science. Could only make guesses. For first, most current answer, we just know, something exists in Universe, which we could not see directly, but have mass and so emit some gravitation, which influence moving of other objects, which we could see. For second, even worse. We only know, we cannot SEE anything in void, but this just mean, something could be there, but we cannot detect it with our current technology, nothing more. When we cannot se anything, and we have not before encountered such phenomenon, we could only speculate on fantastic theories.