Scientists have found evidence to suggest that the universe is replete with low-frequency gravitational waves ripples in the fabric of space-time, predicted by Albert Einstein’s General Theory of Relativity more than 100 years ago.
- Gravitational Waves were first detected in 2015 using an experiment involving Laser Interferometer Gravitational Observatory (LIGO) detectors.
- But those waves were of high frequency and believed to have been produced by the merger of two relatively small black holes that took place about 1.3 billion years ago.
- Scientists have been looking for low-frequency gravitational waves for decades. They believed that such ripples are perpetually rolling through space like background noise.
- Pairs of supermassive black holes, sitting at the centre of galaxies, merge across the universe, generating gravitational waves.
- This breakthrough provides enough data to suggest that there is a gravitational wave background which exists in our universe.
- To discover low-frequency gravitational waves, scientists used entirely different technologies that were carried out by radio astronomers representing five different international teams, including Indian Pulsar Timing Array (InPTA).
- The researchers used six large radio telescopes around the world, including the one in Pune, to study objects called pulsars, distant rapidly-rotating neutron stars that emit pulses of radiation, observed from the Earth as bright flashes of light.
- These bursts take place at exact intervals, and therefore scientists use pulsars as ‘cosmic clocks.
- After examining 25 pulsars over 15 years, Scientists have proposed that the observed inconsistencies were due to deformities caused in space-time by gravitational waves.
- These irregularities showed consistent effects of the presence of gravitational waves.
- LIGO is an international network of laboratories that detect the ripples (gravitational waves) in space-time produced by the movement of large celestial objects like stars and planets.
- These ripples were first postulated in Albert Einstein’s general theory of relativity, which encapsulates our current understanding of how gravitation works.
- The LIGO detectors are sensitive to distance changes that are several orders of magnitude smaller than the length of a proton.