Mark Megahan
Swedish scientists at Chalmers University of Technology “have succeeded in creating light from vacuum.” Theory predicted it more than 40 years ago but this team came up with a nifty new experiment and “managed to capture some of the photons that are constantly appearing and disappearing in the vacuum.”
Photons flicker into light
There is really no such thing as “empty” space. Pumping it down to vacuum doesn’t mean that there’s nothing there in the nothingness. All sorts of ghostlike “virtual” particles lurk beyond the edge of perception. Photons are only one type of them.
As Christopher Wilson explains, “Vacuum is full of various particles that are continuously fluctuating in and out of existence. They appear, exist for a brief moment and then disappear again.”
Wilson and his colleagues “have succeeded in getting photons to leave their virtual state” and become the real kind. In other words, light which can be measured.
All the way back in 1970 physicist Greg Moore predicted it could happen. You simply allow virtual particles to “bounce off a mirror that is moving at a speed that is almost as high as the speed of light.” They call that the Casimir effect.
If you can actually figure out a way to get a mirror moving that fast, call DARPA. They’ll have a big fat check for you. Until then, the Swedish team found a workaround that does the trick to bounce photons around like ping-pong balls.
“Since it’s not possible to get a mirror to move fast enough, we’ve developed another method for achieving the same effect,” Per Delsing brags. He’s a Professor of Experimental Physics at Chalmers. “Instead of varying the physical distance to a mirror, we’ve varied the electrical distance to an electrical short circuit that acts as a mirror for microwaves.”
Quantum interference device
Everyone in the world of physics is slapping their forehead and asking “why didn’t I think of that?” They use what they call a “SQUID.” Their magic “mirror” consists of a quantum electronic component. A “superconducting quantum interference device.”
It happens to be “extremely sensitive to magnetic fields.” They get something to bounce photons off by “changing the direction of the magnetic field several billions of times a second.” That works out to a mirror vibrating at “up to 25 percent of the speed of light.” It worked.
“The result was that photons appeared in pairs from the vacuum, which we were able to measure in the form of microwave radiation,” Delsing reports.
“We were also able to establish that the radiation had precisely the same properties that quantum theory says it should have.” They might get some dynamite money for that in the form of a Nobel Prize.
There are a whole swarm of virtual particle types lurking in vacuum. Göran Johansson, Associate Professor of Theoretical Physics, reveals that the reason why “photons appear in the experiment is that they lack mass.” That means they take a whole lot less energy to tease into existence. Still, you don’t want to pay the lab’s light bill.
“Relatively little energy is therefore required in order to excite them out of their virtual state. In principle, one could also create other particles from vacuum, such as electrons or protons, but that would require a lot more energy.“
