In our common experience, you can't get something for nothing. In the quantum realm, something really can emerge from nothing.
Whoever said, “you can’t get something from nothing” must never have learned quantum physics. As long as you have empty space — the ultimate in physical nothingness — simply manipulating it in the right way will inevitably cause something to emerge. Collide two particles in the abyss of empty space, and sometimes additional particle-antiparticle pairs emerge. Take a meson and try to rip the quark away from the antiquark, and a new set of particle-antiparticle pairs will get pulled out of the empty space between them. And in theory, a strong enough electromagnetic field can rip particles and antiparticles out of the vacuum itself, even without any initial particles or antiparticles at all.
Previously, it was thought that the highest particle energies of all would be needed to produce these effects: the kind only obtainable at high-energy particle physics experiments or in extreme astrophysical environments. But in early 2022, strong enough electric fields were created in a simple laboratory setup leveraging the unique properties of graphene, enabling the spontaneous creation of particle-antiparticle pairs from nothing at all. The prediction that this should be possible is 70 years old: dating back to one of the founders of quantum field theory: Julian Schwinger. The Schwinger effect is now verified and teaches us how the Universe truly makes something from nothing.
In the Universe we inhabit, it’s truly impossible to create “nothing” in any sort of satisfactory way. Everything that exists, down at a fundamental level, can be decomposed into individual entities — quanta — that cannot be broken down further. These elementary particles include quarks, electrons, the electron’s heavier cousins (muons and taus), neutrinos, as well as all of their antimatter counterparts, plus photons, gluons, and the heavy bosons: the W+, W-, Z0, and the Higgs. If you take all of them away, however, the “empty space” that remains isn’t quite empty in many physical senses.
For one, even in the absence of particles, quantum fields remain. Just as we cannot take the laws of physics away from the Universe, we cannot take the quantum fields that permeate the Universe away from it.
For another, no matter how far away we move any sources of matter, there are two long-range forces whose effects will still remain: electromagnetism and gravitation. While we can make clever setups that ensure that the electromagnetic field strength in a region is zero, we cannot do that for gravitation; space cannot be “entirely emptied” in any real sense in this regard.
But even for the electromagnetic force — even if you completely zero out the electric and magnetic fields within a region of space — there’s an experiment you can perform to demonstrate that empty space isn’t truly empty. Even if you create a perfect vacuum, devoid of all particles and antiparticles of all types, where the electric and magnetic fields are zero, there’s clearly something that’s present in this region of what a physicist might call, from a physical perspective, “maximum nothingness.”
All you need to do is place a set of parallel conducting plates in this region of space. Whereas you might expect that the only force they’d experience between them would be gravity, set by their mutual gravitational attraction, what actually winds up happening is that the plates attract by a much greater amount than gravity predicts.
This physical phenomenon is known as the Casimir effect and was demonstrated to be true by Steve Lamoreaux in 1996: 48 years after it was calculated and proposed by Hendrik Casimir.
Similarly, in 1951, Julian Schwinger, already a co-founder of the quantum field theory that describes electrons and the electromagnetic force, gave a complete theoretical description of how matter could be created from nothing: simply by applying a strong electric field. Although others had proposed the idea back in the 1930s, including Fritz Sauter, Werner Heisenberg, and Hans Euler, Schwinger himself did the heavy lifting to quantify precisely under what conditions this effect should emerge, and henceforth it’s been primarily known as the Schwinger effect.
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