The theory that was proposed 41 years ago quoting, “Empty space is not actually an empty space” has finally been proved by scientist.
As reported via newscientist,
Chris Wilson and his colleagues conducted an experiment, by pulling photons out of the void in a process called the dynamical Casimir effect. “It was a difficult technical experiment,” says Wilson. “We were very happy when it worked.”
The effect needs only a single metal mirror, but it must move at close to the speed of light through the sea of virtual photons in empty space. Because the mirror is a conductor, the photons – which are electromagnetic particles – will absorb some of its kinetic energy. They then radiate this extra energy by producing pairs of real photons.
Clearly, moving a mirror at close to light speed is impractical. So the researchers used a superconducting electrical circuit with an oscillator that rapidly alters the distance an electron must travel through the circuit.
The electron’s movement is determined by the location at which the circuit’s electric field falls to zero. To control the circuit’s characteristics, the team used a superconducting quantum interference device. With this SQUID they were able to change the distance from the electron to the zero-field location so quickly that the electron appeared to move at a quarter of the speed of light. This was fast enough for the circuit to emit real photons (Nature, DOI: 10.1038/nature10561). “Particles were produced in pairs, coming right out of the vacuum,” Wilson says.
“This is a significant breakthrough,” says Diego Dalvit, a physicist at the Los Alamos National Laboratory in New Mexico. The energy of virtual photons is cosmologists’ best guess of what lies behind the dark energy that is causing the universe’s expansion to accelerate. The experiment will “open possibilities for doing table-top experiments of cosmology”, Dalvit says.