Astronomers have ‘heard’ the subtle murmur made by gravitational waves echoing throughout the universe for the first time. According to research findings, scientists have discovered a "background hum" permeating the universe at low frequencies, pointing towards the existence of gravitational waves.
The historic feat was captured by scientists using radio telescopes in India, North America, Europe, China, and Australia after nearly a decade of work. The scientists were able to "hear" low-frequency gravitational waves, which are created when huge objects in the universe move around and collide in space. They stretch and compress space-time as they travel through space, a Reuters report explains. Currently, the dominant theory is that gravitational waves are formed by pairs of supermassive black holes at the centre of galaxies that are slowly merging.
"It's really the first time that we have evidence of just this large-scale motion of everything in the universe," Maura McLaughlin, co-director of NANOGrav, the research collaboration that published the results in The Astrophysical Journal Letters, told the Associated Press.
In 1916, theoretical physicist Albert Einstein predicted the existence of gravitational waves, linked to his theory of relativity, which presented gravity as the distortion of space and time by matter. In 2015, the existence of gravitational waves was confirmed when US and Italian observatories observed that they were created when two black holes collided.
In this latest research, scientists focused on investigating waves at much lower frequencies. To find the evidence for gravitational waves, astronomers looked at pulsars, which are the dead cores of stars that exploded in a supernova, according to an AFP report. Radio telescopes around the world focused on 115 pulsars throughout the Milky Way galaxy. Extremely small differences in the timing of the pulses were measured to find the evidence.
Interestingly, India's Giant Metrewave Radio Telescope (GMRT) was one of the world's six large telescopes that played an important role in finding the first-ever evidence of gravitational waves.
Talking to AFP, French astrophysicist Antoine Petiteau said they were able to "detect changes of less than one-millionth of a second across more than 20 years." Notably, the scientists have confirmed that the initial evidence is consistent with Einstein's theory of relativity and the current understanding of the universe.
"We now know that the universe is awash with gravitational waves," Michael Keith of the European Pulsar Timing Array told AFP.
(with inputs from agencies)