OUR UNIVERSE may be inside a black hole which may even contain OTHER universes, scientists have claimed. While many accept the Big Bang theory as gospel, a group of physicists are challenging the norm and claim the maths of it does not quite add up. Black holes are a complete mystery to scientists, but some are arguing each black hole may be a portal to another universe. Nikodem Poplawski, a theoretical physicist from the University of New Haven, is one of the leading establishers of the theory and first came up with he idea when questioning the big bang theory. Mr Poplawski wrote for InsideScience.org: "What started the big bang? What caused inflation to end? What is the source of the mysterious dark energy that is apparently causing the universe to speed up its expansion?" Black holes could birth universes This is where his theory came from, claiming his black hole-universe theory removes the notion of "impossible" singularities. At the beginning of time, 13.8 billion years ago,