A space-time continuum of calm (Image: Ralf Hiemisch/Getty)

EMPTY space may really be empty. 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. A calmer view of the vacuum would also help resolve a nagging inconsistency with dark energy, the elusive force thought to be speeding up the expansion of the universe.

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 …