Gravitational Waves And Light Measured From Same Source! (And Why It’s Good News For India Especially)

The Hubble Space Telescope captured a spectacular image of the bright star-forming ring that surrounds the heart of the barred spiral galaxy NGC 1097. (NASA/ESA/Hubble)
  • Attention! Light and gravitational waves detected from the same cosmic event for the first time!

What a time to be alive and be doing science! For the first time ever, we measured spacetime ripples (aka gravitational waves) and light from the same source in the universe! Our understanding of light and gravity fundamentally changed a century ago thanks to Albert Einstein’s Theory of Relativity and the fact that today we see events in the universe where both these concepts are so elegantly intertwined would have brought a smile on Einstein’s face.

Along with the gravitational detectors LIGO (US) and Virgo (Europe), some 70 observatories and telescope around the world (and space) allowed us to measure the collision of two neutron stars. These stars are about the mass of our Sun, but have a radius of just about 15 km, making them the most extreme matter objects in the universe.

How they observed the same cosmic event through both gravitational waves and light (click to enlarge) How they observed the same cosmic event through both gravitational waves and light (click to enlarge)

This is One of the Biggest Scientific Discoveries of All Time!

This detection is significant in three remarkable ways - first, it allows us to independently test Einstein's General Theory of Relativity as we recorded two different forms of radiation - gravitational waves and light - originating from the same astrophysical source.

Second, we were able to constrain the expansion of our universe and subsequently measure the age of our Universe.

Third, the collision provides us clues on how heavy elements like gold and platinum are produced in our cosmos. Each element of gold that we love to show off in our jewellery, has reached our earth after traveling from such collision of neutron stars from millions of light years from galaxies far far away. Yes, all of us carrying the pride of wearing gold are carrying relics from such cosmic events!

Connection to India

This discovery opens up the long-awaited era of multimessenger astronomy. As a scientist, it is very reassuring to see that India is investing in a field that is only seeing its early days. In future, with LIGO-India, we will be able to more precisely constrain the sky-location of such events as well as the extreme matter physics of such neutron stars.


Building such mega-science projects allows Indian universities to participate in cutting-edge research, which ultimately trickles down all the way to impacting undergraduate education. Imagine first-year college students from local colleges and state universities analysing spacetime rhythms from events that occurred even before life started on this planet!

In combination of other grand science projects, including India's very own space observatory ASTROSAT as well funding one of the world's biggest telescope (Thirty Meter Telescope), I can proudly say there has never been a better time to do space-related science in India.

Dr Karan Jani is a part of the team of scientists that made this discovery. This article was published on Dr Jani’s Linkedin page and has been republished here with permission.

Image credit: NASA/ESA/Hubble

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