Stellar black holes form from the collapse of massive stars at the end of their lives, typically weighing 3 to 50 times the mass of the sun. When a star runs out of fuel, it explodes in a supernova, leaving behind a region so dense that nothing can escape, not even light.
Primordial black holes, by contrast, are theoretical objects that could have formed less than a second after the Big Bang from extremely dense regions of the early universe. Unlike stellar black holes, they could be much lighter and are ancient relics from when the universe contained mostly hydrogen and helium.
While black holes are typically known for consuming everything around them, physicists have long theorised that they eventually explode at the end of their lives through a process called Hawking radiation. Previously, scientists believed such explosions occurred only once every 100,000 years. However, new research, published in the journal Physical Review Letters, suggests we might witness this extraordinary phenomenon much sooner than expected.
“We believe that there is up to a 90% chance of witnessing an exploding black hole in the next 10 years, the key is that our current fleet of space and ground based telescopes are already capable of detecting such an explosion,” said Aidan Symons, a graduate student from the University of Massachusetts.
The black holes most likely to explode aren’t the massive stellar remnants we typically think of, but rather the primordial black holes (PBHs.) As physicist Stephen Hawking showed in 1970, the lighter a black hole is, the hotter it becomes and the more particles it emits through Hawking radiation. As PBHs evaporate, they become ever lighter, and so hotter, emitting even more radiation in a runaway process until explosion.
The breakthrough came when the team of researchers started to question long held assumptions about black holes’ electrical properties. While standard black holes have no electrical charge, the team explored what might happen if primordial black holes formed with a tiny electric charge involving hypothetical heavy particles they call “dark electrons.”
A dark electron would be like a much heavier version of the regular electron, but interacting through dark electromagnetic forces instead of ordinary electromagnetism. In theoretical models called dark-QED, these particles would carry dark electric charge and interact via dark photons, potentially affecting how matter behaves around the black holes.
The research team made a different assumption about the electrical properties of primordial black holes. They postulate that their model shows if a primordial black hole forms with a small dark electric charge, it should be temporarily stabilized before finally exploding. This stabilization effect could dramatically increase the likelihood of observing such explosions, from once every 100,000 years to potentially once every decade.
An exploding black hole wouldn’t just be a spectacular light show, it would provide scientists with a catalog of every subatomic particle in existence. This includes not only particles we’ve already discovered, like electrons, quarks, and Higgs bosons, but also currently undetected particles, perhaps even dark matter.
The team insist that while they’re not guaranteeing an explosion will occur this decade, the high probability means we should be prepared. Fortunately, our current telescope technology is already capable of detecting the telltale signs of Hawking radiation from an exploding primordial black hole. If their calculations prove correct, we may be able to shed light on one of our oldest questions; where did everything come from?!
The original version of this article was published on Universe Today.
