SCIENTIST DETECTS FOURTH GRAVITATIONAL WAVE
- Over the last three decades, Indian scientists have done foundational work in various aspects of gravitational-wave science, including theoretical calculation of expected signals from astronomical sources, developing sophisticated data analysis techniques for searching weak gravitational- wave signals, and, the current Indian team in the LIGO-Virgo collaboration has made direct contributions.
- The LIGO-Virgo collaboration includes more than a thousand scientists from many different countries, setting a great example in international scientific cooperation. The recent publication has 40 authors from 13 Indian institutions.
- Now the new discovery has taken place, Astronomers say they have detected another set of gravitational waves — ripples in the fabric of space and time traveling throughout the Universe. It’s the fourth time this phenomenon has been measured by the scientists at LIGO( Laser Interferometer Gravitational-Wave Observatory). The same group made history by detecting the first wave signals early last year. While such detections seem to be routine now, this latest discovery is unique since it was also picked up by a separate non-LIGO observatory.
WHAT ARE GRAVITATIONAL WAVES-
Gravitational waves are caused when objects with strong gravity accelerate. As they accelerate , ripples of space travel away from them at the speed of light
HIGHLIGHTS-
- For the first time, the detection was made jointly with the Virgo observatory from Europe.
- Gravitational waves are ripples in space and time, from the merger of two massive black holes.
- The first two detections were made in September and December 2015 in quick succession and the third one came on January 4, 2017.
What does the discovery mean?
- Being able to detect and measure gravitational waves opens up an entire new field of astronomy.
- Gravitational wave astronomy would allow us to look further back in time and deeper inside the most extreme objects in the sky — to the earliest instant after the Big Bang.
- All of our existing knowledge of the universe comes from telescopes, and all telescopes (optical, radio, X-ray etc) rely on light coming from distant objects.
- Telescopes tell us a lot, but the light they detect has been absorbed and scattered by lots of gas and dust between the source and the telescope. At best, we are getting blurry images.
- Like light waves, gravitational waves are imprinted with information about their source — but it is information that light could never provide.
- Gravitational wave astronomy will reveal the insides of distant objects because it will let us "see" their mass.
- And because gravitational waves only interact with gas and dust to a tiny extent, their signal is much cleaner than those from light. The Virgo team hints in their press release that more detections from the three units will be announced sometime soon and some are hoping to hear that they've snagged a measurement, and maybe even a visual, of another big celestial event -- two neutron stars merging.
