New Delhi: Providing base and evidence to Albert Einstein's Theory of General Relativity, waves of energy travelling for more than a billion years gently rattled space-time in the vicinity of Earth.
This disturbance, that was made by gravitational waves, was captured by the Laser Interferometer Gravitational-Wave Observatory (LIGO) facilities in Hanford, Washington, and Livingston, Louisiana, making it the first-ever detection of gravitational waves.
This discovery gave way to numerous scientific possibilities that could further pave the way for scientists to step into new horizons to understand the working of the universe.
However, not even a second after this news started pouring in, the Gamma-ray Burst Monitor (GBM) on NASA's Fermi Gamma-ray Space Telescope picked up a brief, weak burst of high-energy light consistent with the same part of the sky.
This seemed strange since black holes are expected to merge “cleanly,” without producing any sort of light and this is where the Fermi Gamma-ray Space Telescope comes in.
As per NASA, detecting light from a gravitational wave source will enable a much deeper understanding of the event. Fermi's GBM sees the entire sky not blocked by Earth and is sensitive to X-rays and gamma rays with energies between 8,000 and 40 million electron volts (eV). For comparison, the energy of visible light ranges between about 2 and 3 eV.
NASA also quoted Valerie Connaughton, a GBM team member at the National Space, Science and Technology Center in Huntsville, Alabama, and lead author of a paper on the burst now under review by The Astrophysical Journal, who said that, “This is a tantalizing discovery with a low chance of being a false alarm, but before we can start rewriting the textbooks we’ll need to see more bursts associated with gravitational waves from black hole mergers.”
The US space agency also released a video demonstrating the visualization of merging black holes and gravitational waves.
Explaining the visualization, NASA said, “The yellow structures near the black holes illustrate the strong curvature of space-time in the region. Orange ripples represent distortions of space-time caused by the rapidly orbiting masses. These distortions spread out and weaken, ultimately becoming gravitational waves (purple). The merger timescale depends on the masses of the black holes. For a system containing black holes with about 30 times the sun’s mass, similar to the one detected by LIGO in 2015, the orbital period at the start of the movie is just 65 milliseconds, with the black holes moving at about 15 percent the speed of light. Space-time distortions radiate away orbital energy and cause the binary to contract quickly. As the two black holes near each other, they merge into a single black hole that settles into its "ringdown" phase, where the final gravitational waves are emitted. For the 2015 LIGO detection, these events played out in little more than a quarter of a second. This simulation was performed on the Pleiades supercomputer at NASA's Ames Research Center.”
Watch the video below:
(Video courtesy: NASA/J. Bernard Kelly (Goddard), Chris Henze (Ames) and Tim Sandstrom (CSC Government Solutions LLC)