Scientists have calculated what would happen if, after the collision of two black holes, a bubble of absolute vacuum managed to escape its fate
Many recent research suggests that the extreme gravitational force created in the vicinity of a black hole could give rise to a kind of “foam” of quantum vacuum bubbles.
These bubbles, which carry a vacuum more absolute than the vacuum we experience on Earth, or in any context far removed from quantum physics, could in a flash engulf the entire universe.
Quantum vacuum bubbles
What we know is not an absolute vacuum: physicists call it “false vacuum”, because there is – at least hypothetically – a state of matter in which energy levels are at the absolute minimum possible.
The vacuum, as we know it, is never absolute: this is easily demonstrated by experiments that reproduce the vacuum thanks to the tunnel effect, which recreate states in which energy levels are lower than in the “false vacuum”.
The condition of false vacuum is called meta-stable, and is the one that ultimately allows the existence of the universe: if any part of the universe were to fall into a quantum vacuum bubble, the laws of physics as we know them would be canceled in less than a second.
The quantum vacuum bubble could expand at the speed of light and swallow the entire universe: is what supports a new study led by Rostislav Konoplich, Manhattan College in New York.
Konoplich and his team have calculated what could happen if one of these bubbles were to be created in the collision between two black holes.
They could destroy the entire universe
When two black holes collide, in the region between the colliding event horizons, the gravitational attraction of the two celestial bodies can balance each other, so, the research says, “for a short period of time there could exist a bubble trapped between the two black holes.”
Generally, the incredible gravitational attraction exerted by the individual black holes is enough for the bubbles to be immediately engulfed by one of the two. But what if that doesn’t happen? What if the equilibrium state allowed one or more quantum vacuum bubbles to escape its fate?
Researchers have calculated that if many bubbles were to collide with each other in the hypothetical “gravitational equilibrium” region between the two colliding black holes, the intersecting surface could become infinitely dense.
This means that from the encounter of two black holes a third one could be generated, a “micro black hole” that can last only 10 milliseconds, before being swallowed by one of the larger ones.
But we know that these bubbles, once they have formed, “expand quite rapidly and quickly reach the speed of light”: if they were outside the event horizon, therefore, they could expand instead of being absorbed into the black hole.
The fact that the universe still exists tells us that such an eventuality is extremely rare, but the results of the research of Konoplich and colleagues are quite clear: “if one of these quantum vacuum bubbles managed to escape, it would destroy the universe”.