However, one of the rules of relativity is that different observers will perceive different realities: observers in relative motion or in regions where the spacetime curvature is different, in particular, will disagree with one another. To any observer located anywhere in the Universe, that "energy of empty space," which we call the zero-point energy, will appear to have the same value no matter where they are. These diagrams may show particles and antiparticles popping in and out of existence, but that is only a calculational tool these particles are not real. this theory, due to Feynman, Schwinger, and Tomonaga, led to them being awarded the Nobel Prize in 1965. They are not actually produced, they do not interact with real particles, and they are not detectable by any means.Ī few terms contributing to the zero-point energy in quantum electrodynamics. But it's a calculational technique only the particles and antiparticles are not real but are virtual instead. There's a germ of truth in the "particle-antiparticle pair production" analogy, and it's this: in quantum field theory, you can model the energy of empty space by adding up diagrams that include the production of these particles. And that's too bad, because the actual scientific story is no more complex, but far more illuminating.Įmpty space really does have quantum fields all throughout it, and those fields really do have fluctuations in their energy values. He knew that this analogy was flawed and would lead to physicists thinking incorrectly about it, but he chose to present it to the general public as though people weren't capable of understanding the real mechanism actually at play. What's odd about this explanation is that it's not the one he used in the scientific papers he wrote concerning this topic. Andrew Hamilton / JILA / University of Colorado But outside the event horizon, owing to the curvature of space, radiation is generated, carrying energy away and causing the mass of the black hole to slowly shrink over time. moving walkway or a waterfall, depending on how you want to visualize it. And the individual quanta emitted have tiny energies over quite a large range.īoth inside and outside the event horizon of a Schwarzschild black hole, space flows like either a. It gets emitted from a large region outside the event horizon, not right at the surface. Hawking radiation is made almost exclusively of photons, not a mix of particles and antiparticles. Of course, all three of those points are not true. that every quantum of emitted radiation must have a tremendous amount of energy: enough to escape from almost, but not quite, being swallowed by the black hole.that all of the Hawking radiation, which causes black holes to decay, will be emitted from the event horizon itself, and.Hawking radiation was composed of a 50/50 mix of particles and antiparticles, since which member falls and which one escapes will be random,.If that explanation were true, then that would mean: That was the first explanation that I, myself a theoretical astrophysicist, ever heard for how black holes decay. This flawed analogy continues to confuse generations of physicists and laypersons alike. with particle-antiparticle pairs and that one member can escape (carrying positive energy) while the other falls in (with negative energy), leading to black hole decay. In Hawking's most famous book, A Brief History of Time, he makes the analogy that space is filled. And that, he proclaims, is why black holes lose mass, decay, and where Hawking radiation comes from. But right near the event horizon, one member can fall in while the other escapes, carrying real energy away. Far outside of the black hole, it's the same deal. Inside the black hole, both members stay there, annihilate, and nothing happens. All throughout space, he asserts, these particle-antiparticle pairs are popping in and out of existence. It's here that Hawking's famous picture - his grossly incorrect picture - comes into play. One visualization that's commonly used is to think about empty space as being truly empty, but populated by particle-antiparticle pairs (because of conservation laws) that briefly pop into existence, only to annihilate away back into the vacuum of nothingness after a short while. But excited states, or states that correspond to higher-energies, correspond to either particles or antiparticles. In the context of quantum field theory, the lowest-energy state of a quantum field corresponds to no particles existing.
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