Astronomers across the world announced on Thursday that they have found the first evidence of a long-theorised form of gravitational waves that create a “background hum” rumbling throughout the universe.
The breakthrough — made by hundreds of scientists using radio telescopes in North America, Europe, China, India and Australia after years of work — was hailed as a major milestone that opens a new window into the universe.
First predicted by Albert Einstein more than a century ago, gravitational waves are ripples in the fabric of the universe that travel through everything at the speed of light almost entirely unimpeded.
Their existence was not confirmed until 2015, when the US and Italian observatories detected the first gravitational waves created by two black holes colliding.
These “high-frequency” waves were the result of a single violent event that sends a strong, short burst rippling towards Earth.
But for decades scientists have been searching for low-frequency gravitational waves, thought to be constantly rolling through space like background noise.
Joining forces under the banner of the International Pulsar Timing Array consortium, scientists working at gravitational wave detectors on several continents revealed on Thursday they have finally found strong evidence of these background waves.
“We now know that the universe is awash with gravitational waves,” Michael Keith of the European Pulsar Timing Array told AFP.