Production of light from vacuum
Scientists at Chalmers have created Chalmers. This process was first predicted about 40 years ago. They have gotten success in capturing some of the light particles, i.e. photons, appearing and disappearing in the vacuum.
This research has been done by Chalmers scientist, Christopher Wilson, light from vacuum and co-workers and published online in the November 16 issue of the Journal Nature.
Scientists based their experiment on the most unexpected principle of Quantum Mechanics i.e. many particles in the vacuum continuously come in and go out of existence. Those particles appear for a brief moment and then disappear again and they are referred to as virtual particles. Scientists successfully take photons out of their virtual state and make them real photons i.e. observable light. The physicist Moore hypothesized in (round about) 1970 that virtual photons can change to real photons only if they are permitted to bounce off a mirror moving at a speed same as the speed of light. The same phenomenon known as the dynamical Casimir effect has been observed by the scientists of Chalmers.
Scientists brilliantly changed the electrical distance to an electrical short circuit, which acted as the mirror for microwaves. They did this, as it is not possible to make the mirror to move at a faster speed close to light. The mirror for microwaves, consists of quantum electronic component referred to as a SQUID (Superconducting quantum interference device) that is very much sensitive to magnetic fields. Scientists were able to make this mirror to vibrate at a speed of up to 25% of the speed of light by varying the direction of the magnetic field several billions of times a second.
Per Delsing, said,
The result was that photons appeared in pairs from the vacuum, which we were able to measure in the form of microwave radiation. We were also able to establish that the radiation had precisely the same properties that quantum theory says it should have when photons appear in pairs in this way.
In the experiment, mirror transferred some of its kinetic energy to virtual photons helping them to materialize. Göran Johansson, Associate Professor of Theoretical Physics told that photons appear in the experiment, as they have no mass.
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.
Reference:
C. M. Wilson, G. Johansson, A. Pourkabirian, M. Simoen, J. R. Johansson, T. Duty, F. Nori & P. Delsing, (2011). Observation of the dynamical Casimir effect in a superconducting circuit. Per Delsing, doi:10.1038/nature10561.
