Earlier this year, Stephen Hawking revised his theory of black holes to state that the “event horizon” which is a point of no return for everything—including light—cannot exist because it goes against everything that is known about information preservation in quantum physics. However, there were still some unresolved issues with Hawking’s theory; issues which Chris Adami from Michigan State University claims to have resolved. The results of this study have been published in an open access format in the journal Classical and Quantum Gravity.
Nearly 40 years ago, Hawking proposed a radiation that is emitted from black holes, now known as Hawking radiation. The radiation was believed to slowly evaporate the black hole and then disappear, effectively eliminating it and everything that has ever entered the black hole.
Unfortunately, this creates an information paradox and does not agree with any known law of physics. If this were true, it would mean that the Universe itself was fundamentally unpredictable. If it doesn’t disappear, then where does the information go? Adami’s groundbreaking new study incorporates all of Hawking’s original calculations and combines them with what is now known about quantum systems.
The missing link, it seems, was the radiation’s stimulated emission. This process was first described by Albert Einstein in 1917: when a photon hits an electron, the electron can be forced from the excited state down to the ground state and that energy difference manifests as another photon. Essentially, it works like a copy machine: one photon in, two photons out. This is the same principle that allows us to have Light Amplification by Stimulated Emission of Radiation; more commonly known as laser. Before light is drawn into the black hole, Adami determined, a copy is made that does not get destroyed. Thus, the information is preserved.
Though it will take some time for other scientists to check over the math and verify Adami’s work, it has already received some support. Paul Davies, a theoretical physicist from Arizona State University agrees with the conclusion. “In my view Chris Adami has correctly identified the solution to the so-called black hole information paradox,” Davies said in a press release. “Ironically, it has been hiding in plain sight for years. Hawking's famous black hole radiation is an example of so-called spontaneous emission of radiation, but it is only part of the story. There must also be the possibility of stimulated emission – the process that puts the S in LASER.”
According to Adami: “Stephen Hawking’s wonderful theory is now complete in my opinion. The hole in the black hole theory is plugged, and I can now sleep at night.”
Author's note: An earlier version of this article read: "... when a photon hits an electron, the electron can be forced from the excited state down to the ground state and that energy difference manifests as another proton..." This is incorrect, as it should have said "manifests as another photon." It was a simple typo, but understandably seems to have caused some confusion. The body of the text has been corrected, and I apologize for any inconvenience or confusion it caused. -Lisa