Casimir effect
The Casimir effect is a pull between two uncharged surfaces set very close together, caused by the fluctuations of empty space. Shake that emptiness fast enough and it gives off real light.
In the late 1940s, at Philips Laboratories, Hendrik Casimir worked out that two parallel conducting plates placed very close together should attract. Nothing acts on them but empty space: quantum theory says a vacuum teems with virtual particles, and the plates alter those fluctuations in the narrow gap. The pull fades fast with distance, and it was 1997 before an experiment matched the prediction to within 5 percent. In 2011, a circuit shook that vacuum and pulled real photons out of it.
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