The detection of gravitational waves in the afterglow of the Big Bang — if confirmed — opens a new chapter in astronomy, cosmology and physics. The signature, seen by the BICEP2 radio telescope at the South Pole, packs at least three discoveries into one: It provides the most direct evidence for the existence of the waves predicted by Einstein; it is the proof of ‘cosmic inflation’ that physicists had been eagerly awaiting; and it opens a window into the unification of the fundamental forces of nature and into quantum gravity. In this special collection, Nature News has the most comprehensive and up-to-date coverage of the breakthrough and its aftermath.
Discovering gravitational waves would not only validate Einstein's theory of gravitation but also reveal aspects of the Universe's earliest moments. The hunt for these elusive ripples is now well under way.
Cosmic gravitational waves could provide unprecedented information on the early Universe. The effects that are of interest are small, but experiments are gradually achieving a sensitivity that will test cosmological models.