Supermassive Black Holes might Be Hiding Entire Universes Inside

Bubbles of space-time cropped up during the early stages of our cosmos, ultimately forming black holes that were connected to us by wormholes according to a new theory. Research displays that these bubbles ultimately lost energy, and collapsed into a black hole that was so big, it produced its own universe inside – linked to us by the secret door.

These wormholes would have been very short-lived – no more than fractions of a second. During that time, our universe would have been linked to a vast multiverse – loads of other universes. Andrei Linde told New Scientist: "This subject is actually, really deep. We are just starting to touch the surface and find new things about the multiverse."

Researchers believe that the universe grows through 'eternal inflation', which proposes space-time grows exponentially. With this, however, small bubbles of space-time arise randomly. As the universe continues to grow, the bubbles grow with it – getting bigger and bigger until the universe stops developing. At that point, the bubbles do one of two things based on how big it has become.

The smaller bubbles shrink into a normal black hole – of which it is estimated there are about 100 million in our galaxy alone. Though, the greater bubbles of space time generate equally bigger black holes. These voids are so big, they themselves have a whole new universe with eternal inflation. For a tiny amount of time after they form, our cosmos will be connected to that cosmos by a wormhole – similar to the film Interstellar.

"The opportunity has passed for us to send signals to these other universes," Jaume Garriga, co-author of the research, told New Scientist. He describes how the wormholes close almost instantaneously after they open, blocking anything from entering.

This new research probably opens the door to one of astrophysics' biggest mysteries. Researchers struggle to understand how supermassive black holes became so big, because theoretically they should not; they have not been around long enough to suck in sufficient material to grow that big. However, now there is a theory that black holes, which contain a isolated universe, could have started out much bigger than previously believed – as a bubble of space time that grew with the universe it's already in.