A team of physicists say they have proved a 70-year-old quantum theory that says something can be created out of nothing.
An experiment to study the flow of “low valence” electrons happened to succeed in creating an analogue of particle-antiparticle pairs where nothing had previously existed, using only an electric field and the almost magical properties of the 2-D material graphene were used. The experiment was conducted in January by a research team working at the University of Manchester.
Previous theories suggested that such a process could only take place in ultra-high-energy environments, such as near a black hole or the center of a neutron star. However, the most recent breakthrough has been made using standard laboratory equipment.
Schwinger effect theorized over 50 years ago
In physics there are situations in which individual particles can be manipulated in order to create additional particles seemingly out of nowhere. For example, if you take a quantum particle known as a meson and try to rip away its quark, a brand new set of particle-antiparticle pairs will appear between them out of the void of empty space. However, this situation involves starting with something – a meson – and creating more “somethings” from it.
But as early as 1951, Julian Schwinger, one of the founders of quantum electrodynamics and a physicist who won the Nobel Prize in 1964, suggested that it should be possible to create matter from empty space even when there is nothing there, as long as you disturb that empty space Room with a sufficiently strong electric field. Since then, this entirely theoretical concept has been known simply as the Schwinger effect. Now a team of researchers has shown that this effect is real by essentially creating something out of nothing.
Nothing of nothing means nothing. Unless you have a strong electric field
“In the universe we inhabit, it is really impossible to create “nothing” in a satisfactory way. Anything that exists at a fundamental level can be broken down into discrete units — quanta — that cannot be further broken down,” writes Ethan Siegel think big, which explains the fundamentals of the recent physics breakthrough. “These elementary particles include quarks, electrons, the electron’s heavier cousins (muons and taus), neutrinos and all their antimatter counterparts, as well as photons, gluons and the heavy bosons: W+, W-, Z0 and the Higgs. However, if you take them all away, the “empty space” that is left is in many ways not entirely empty.”
What remains is the quantum field, the general background energy that permeates the entire universe (cue war of stars “die Kraft” music!) According to Schwinger’s theory, if you apply a sufficiently strong electric field to a completely empty region of space, the quantum field of that space will capture some of that electric energy and create particle-antiparticle pairs out of thin air.
Already in January University of Manchester Scientists were working on the conduction of “valence electrons,” essentially trying to get all classes of electrons to join the flow, by tinkering with graphene, a material that is inherently practically two-dimensional. This unique structure helps this type of experiment by limiting the paths that elementary particles like electrons can take, hopefully resulting in a substantially smooth flow of electrons when the right amount of electrical energy is pumped into the system. However, when the team actually began their experiments, something unexpected happened.
“They filled their simulated vacuum with electrons and accelerated them to the maximum speed allowed by graphene’s vacuum, which is 1/300th the speed of light,” according to a recent researcher University of Manchester Release declared. “At this point, something seemingly impossible happened: electrons appeared to become superluminous, delivering an electric current higher than allowed by the general rules of quantum physics of condensed matter. The origin of this effect was explained as the spontaneous generation of additional charge carriers (holes).”
As already mentioned, this result was somewhat unexpected: the creation of an analogue of electron-positron pairs where previously only empty space had existed. In fact, at the laboratory level, this electric field was strong enough to create an actual something out of nothing.
“Key signatures of the out-of-equilibrium state are current-voltage characteristics resembling those of superconductors, sharp spikes in differential resistance, a sign reversal of the Hall effect, and a clear anomaly caused by the oscillator-like generation of hot electrons. Hole plasma,” the researchers write in their published article.
This anomalous electron-hole plasma turns out to be a perfect analogue of the particle-antiparticle pair predicted by Schwinger. So even using a weak electric field (at least compared to the center of a black hole or a neutron star), the team inadvertently proved the Schwinger effect and did something where essentially nothing had been before.
“When we first saw the spectacular properties of our superlattice devices, we thought, ‘Wow… that could be some kind of new superconductivity,'” explained Dr. Roshan Krishna Kumar, one of the co-authors of the publication. “Although the response is similar to those routinely observed in superconductors, we soon found that the puzzling behavior was not superconductivity, but rather something from the field of astrophysics and particle physics.”
That something, in this case, was a result of the Schwinger effect.
“It’s strange to see such parallels between distant disciplines,” added Kumar.
“People typically study electronic properties using tiny electric fields, which allow for easier analysis and theoretical description,” said the publication’s first author, Dr. Alexey Berduygin, a postdoc of The University of Manchester. “We decided to use various experimental tricks to increase the strength of electric fields as much as possible in order not to burn our devices.”
dr Na Xin, co-lead author of the study, said it was an unexpected but pleasant surprise given the risks of taking their equipment to such extremes.
“We were just wondering what might happen at that extreme,” Xin said. “To our surprise, it was the Schwinger effect rather than smoke that came out of our setup.”
Something is still better than nothing
The researchers note that their experiments were low in energy enough that the formation of true electron-positron pairing was still unattainable. But, they say, the analog plasma “hole” created is evidence that the Schwinger effect is real and that given enough energy, material particles can be created out of thin air.
So it may be a long time before laboratory devices large enough to create matter from nothing can make things like food replicators or matter-energy transporters a reality. But given the results of the Manchester team’s experiments, the idea of making something out of nothing is officially proven.
“With electrons and positrons (or ‘holes’) literally appearing out of nowhere, simply ripped out of the quantum vacuum by electric fields itself, this is another way the universe is demonstrating the seemingly impossible,” says Siegel.
“We really can make something out of nothing!”
Follow and connect with author Christopher Plain on Twitter @plain_fiction.