Astrophysicist Niayesh Afshordi says that our universe may be the byproduct of a dead star in another universe, an expanding 3D membrane of a black hole that floats through a 4D bulk universe. Like your brain after Saturday night.
His model explains many of the mysteries that science hasn't solved yet, like the uniform temperature of our universe. It also provide a reason for the Big Bang—but why did that 4D black hole result in our 3D universe? How did the 4D universe appear? And are there multiple 3D universes like ours, all membranes of different black holes in that 4D universe?