Astronomers say they have found the first evidence of “gravitational waves” – ripples in the fabric of space-time – bolstering the Big Bang theory of the birth of the universe 13.8bn years ago.

The discovery, by a new telescope at the South Pole, supports a widely held belief about the origin of the universe, called cosmic inflation. Scientists can now be more confident the Big Bang triggered expansion at an unbelievable rate, with the newborn universe growing a trillion trillion trillion times in an infinitesimal fraction of a second.

“Detecting this signal is one of the most important goals in cosmology today,” said John Kovac of Harvard University, the project leader. Cosmologists not directly involved in the research, announced at the Harvard-Smithsonian Centre for Astrophysics, hailed the discovery as a landmark in understanding the universe.