“And there was light.” Just where did light come from? Quantum theory postulates that empty space isn’t quite a vacuum but is actually a writhing foam of particles (virtual photons) flitting in and out of existence. Per Delsing, a physicist at the Chalmers University of Technology, and his colleagues used a superconducting quantum interference device, or SQUID, to behave like a mirror moving back and forth at about 5 percent of the speed of light. Quantum theory states that if a mirror is traveling through the vacuum at nearly the speed of light, it can absorb energy from some of these virtual photons, and re-emit it as actual photons. In their experiment, they observed a shower of microwave photons shaken loose from the vacuum.
Read more about this landmark proof at: Nature.