(Image: Matthew Richardson)
IT DEPENDS what you mean by nothing. Ask a physicist about a vacuum, the very definition of nothingness for most of us, and they will tell you it is pulsing with activity. According to quantum theory, in a vacuum wave-like fields are constantly fluctuating, producing particles and their antimatter equivalents that fizzle in and out of existence. So even in the depths of interstellar space, there is plenty going on in what we call zilch.
This idea leads to some outlandish predictions. In 1948, the physicist Hendrik Casimir proposed that if you place two parallel metal plates close to each other in a vacuum, there will be more quantum electromagnetic fluctuations either side of the plates than between them. Their proximity limits the wavelength of fluctuations in that space, creating a force pushing the plates together. The phenomenon became known as the Casimir effect.
It’s a weakling force but it has been detected. And more recently, physicists like Chris Wilson, now at the University of Waterloo in Canada, have tried to prove another eccentric prediction: that it is possible to use the effect to release latent energy. Instead of allowing the fluctuations to tug on the plates, you rapidly force the plates together to squeeze their wavelengths – and force out photons (see diagram).
Trouble is, you can’t accelerate even the tiniest mirror to the huge speeds required. So in 2011 Wilson and his colleagues tested the dynamical Casimir effect, as it’s known, by using rapidly changing electrical currents to simulate the effect of minuscule mirrors whooshing together at a quarter of the speed of…
