Though quantum theory suggests that a vacuum should be fizzing with particle activity, it turns out that this paradoxical picture of nothingness may not be needed.
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Quantum field theory tells us that short-lived pairs of particles and their antiparticles are constantly being created and destroyed in apparently empty space. A branch of the theory, called quantum chromodynamics (QCD) - which explains how gluons and quarks, the particles that make up protons and neutrons, behave - predicts that a vacuum should be awash with an interacting sea or "condensate" of quarks and gluons.
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Now Stanley Brodsky of the SLAC National Accelerator Laboratory in Menlo Park, California, and colleagues have found a way to get rid of the discrepancy. "People have just been taking it on faith that this quark condensate is present throughout the vacuum," says Brodsky.

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