Researcher Mathematically Proves that Black Holes Do Not Exist
A black hole has long served as a metaphor for nothingness, but is it possible that they literally don't exist? UNC-Chapel Hill physicist Laura Mersini-Houghton claims to have mathematically proven that black holes cannot exist in our universe.
Predicted as an extrapolation of Einstein's theory of relativity, black holes are thought to form when massive stars undergo gravitational collapse. Throughout the life of a star, gravity pushes the star towards collapse while pressure from nuclear reactions in the core prevents said collapse. When the star exhausts its nuclear fuel, the gravity overtakes the pressure and the star explodes into a supernova. The outer layers of the star are expelled into deep space, while the core collapses into itself until it becomes an infinitely dense pinpoint of matter, called a singularity. The singularity becomes the center of a black hole, from which nothing can escape once it passes the boundary (event horizon) unless it travels faster than light, so nothing in the known universe can escape. The existence of black holes has been all but taken for granted, even though they elude observation almost by definition.
In 1974, Stephen Hawking proposed a new feature of black holes that would be amenable to experimental confirmation: due to quantum effects near the event horizon, black holes emit small amounts of thermal radiation, known as Hawking radiation. When the presence of Hawking radiation in the cosmos was eventually confirmed, this was taken as proof of the existence of black holes. But now, Mersini-Houghton has theorized that Hawking radiation may not come from black holes at all, but rather from the collapsing star itself. Her theory aligns with Hawking's, and the majority of cosmologists, up to the point that the star collapses. The star itself emits the radiation, and by doing so also sheds mass, and consequently lacks the density to form a singularity.
From the paper: "Due to the negative energy Hawking radiation in the interior, the collapse of the star stops at a finite radius, before the singularity and the event horizon of a black hole have a chance to form. That is, the star bounces instead of collapsing to a black hole."
Mersini-Houghton's paper has not yet been peer-reviewed, but it does have the advantage of solving the black hole information loss paradox. According to the classical theory of black holes, physical information is destroyed within the event horizon. But one of the fundamental tenets of quantum mechanics, called unitarity, postulates that physical information is encoded into a system's wave function, and therefore is always conserved in the quantum sense. Any and all efforts to reconcile the two theories in the context of black holes have been incoherent.
"Physicists have been trying to merge these two theories – Einstein's theory of gravity and quantum mechanics – for decades, but this scenario brings these two theories together, into harmony," said Mersini-Houghton. "And that's a big deal."
If black holes truly do not exist, then Mersini-Houghton's research would have reverberating repercussions in physics and cosmology. Cosmologists would need to reevaluate countless theories of our universe that involve black holes, arguably the most significant being the Big Bang. The most common conception of the Big Bang involves all the matter in the universe exploding from a single point, or a singularity. If singularities are a physical impossibility, then the entire theory of the origin of our universe could be threatened.
"I'm still not over the shock," said Mersini-Houghton. "We've been studying this problem for a more than 50 years and this solution gives us a lot to think about."