A team of researchers has confirmed Stephen Hawking’s prediction of black hole evaporation via Hawking radiation, although they have provided an important modification. According to their research, the event horizon (the boundary where nothing can escape the black hole’s gravitational pull) is not as important as previously believed in producing Hawking radiation. Instead, gravity and the curvature of spacetime play significant roles in this process. This insight extends the scope of Hawking radiation to all massive matter in the universe, suggesting that over a long enough period of time, everything in the universe will evaporate.
Research shows that Stephen Hawking was mostly right about black holes being vaporized by Hawking radiation. However, the study highlights that this radiation does not necessarily have an event horizon, and that gravity and space-time curvature play significant roles. The findings suggest that all massive objects, not just black holes, may eventually evaporate due to a similar radiative process.
New theoretical research by Michael Vondrak, Walter van Suijlekom and Radboud University’s Heino Falke shows that Stephen Hawking was, if not completely, right about black holes. Due to Hawking radiation, black holes eventually evaporate, but the event horizon is not as important as believed. Gravity and the curvature of space-time also cause this radiation. This means that all massive matter in the universe, such as the remnants of stars, will eventually evaporate.
Using a clever combination of quantum physics and Einstein’s theory of gravity, Stephen Hawking argued that the spontaneous creation and destruction of pairs of particles must occur near the event horizon (beyond which they cannot escape gravity).[{” attribute=””>black hole). A particle and its anti-particle are created very briefly from the quantum field, after which they immediately annihilate. But sometimes a particle falls into the black hole, and then the other particle can escape: Hawking radiation. According to Hawking, this would eventually result in the evaporation of black holes.
Schematic of the presented gravitational particle production mechanism in a Schwarzschild spacetime. The particle production event rate is highest at small distances, whereas the escape probability [represented by the increasing escape cone (white)] At large distances is very high. Credit: Physical Review Letters
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In this new study, Radboud University researchers revisited this process and investigated whether or not the existence of an event horizon actually matters. They combined techniques from physics, astronomy and mathematics to investigate what happens when such pairs of particles are created in the neighborhoods of black holes. The study shows that new particles can also be created beyond this horizon. Michael Vondrak: “We demonstrate that in addition to the well-known Hawking radiation, there is also a new radiation.”
Everything evaporates
Van Suijlekom: “We show that the curvature of space-time beyond the black hole plays a large role in generating the radiation. Particles are already separated by the tidal forces of the gravitational field. While it was previously thought that radiation was not possible without an event horizon, this study shows that this horizon is not necessary.
Falke: “That is, objects without an event horizon, such as the remnants of dead stars and other large objects in the universe, also have this type of radiation. And, after a very long time, everything in the universe will eventually evaporate, like black holes. This changes not only our understanding of Hawking radiation, but also our view of the universe and its future.
The study was published on June 2 DOI: 10.1103/PhysRevLett.130.221502
Michael Wondrak is excellence fellow at Radboud University and an expert in quantum field theory. Walter van Suijlekom is a Professor of Mathematics at Radboud University and works on the mathematical formulation of physics problems. Heino Falcke is an award-winning Professor of Radio Astronomy and Astroparticle Physics at Radboud University and known for his work on predicting and making the first picture of a black hole.
