India To Set Up Gravitational-Wave Observatory

Prime Minister Narendra Modi has announced that India will soon set up a Laser Interferometer Gravitational-Wave Observatory (LIGO) to study gravitational waves.

In his monthly radio programme “Mann ki Baat” (To mind) on Sunday, Prime Minister Modi said that the Indian scientists have been studying gravitational waves for long, but the LIGO would make their job systematic.

It will be the third such laboratory in the world, as the US has Hanford in Washington and Livingston in Louisiana. The Indian premier stressed: “Recently, the Gravitational Waves have been discovered by the scientific community of the world, which is indeed a major achievement. We should be proud of the fact that Indian scientists were also part of it. Keeping this in mind, we have taken a decision to open a LIGO in India.”

Modi explained that LIGO would be a national facility for gravitational-wave research and it would create opportunities for the Indian scientific community to take part in detector development, observation and data analysis.

Meanwhile, the National Aeronautics and Space Administration (NASA) has invited India to explore Mars jointly with the US. In a letter to the Indian government, the agency of the US Federal government responsible for the civilian space programme as well as aeronautics and aerospace research has mentioned that it will also send astronauts to New Delhi to discuss their future plans with their Indian counterparts. The South Asian country has immediately accepted the proposal, as it is interested in exploring the Red Planet jointly with the US.

Earlier, the US praised India’s maiden mission to Mars – “Mangalyaan”, saying that the Indian Space Research Organisation (ISRO) opened the eyes of the global community on its capabilities at undertaking low cost, high-value inter-planetary mission.

Charles Elachi, the Director of Jet Propulsion Laboratory (JPL) – a part of NASA and an institution famous for piloting most of the American planetary exploration efforts with rovers (like Curiosity), has welcomed NASA’s move, saying that India and the US should jointly explore Mars and send astronauts to the Red Planet.


    By Rodney A. Brooks
    author of “Fields of Color: The Theory That Escaped Einstein”.

    The current detection of gravitational waves at LIGO (Laser Interferometer Gravitational-Wave Observatory) has grabbed the mind of the public. It will stand as one of the great feats of experimental physics, in addition to the famous Michelson-Morley study of 1887 which it resembles. In fact by comparing these two experiments, you will find that comprehending gravitational waves is not as challenging as you think.

    Contraction. Michaelson and Morley determined the speed of light at varying times as the earth moved around its orbit. To their – and everyone’s – surprise, the speed turned out to be continuous, independent of the earth’s motion. This detection caused great consternation until George FitzGerald and Hendrick Lorentz came up with the sole feasible explanation: objects in motion contract. Einstein then showed that this reduction is a result of his Principles of Relativity, but without saying why they contract (other than a desire to conform to his Principles). In fact Lorentz had previously provided a partial explanation by showing that motion affects the way the electromagnetic field interacts with charges, causing objects to contract. However it wasn’t until Quantum Field Theory came along that a full explanation was found. In QFT, at least in Julian Schwinger’s version, everything is made of fields, even space itself, and motion affects the manner all fields interact.

    Waves. Electromagnetic waves, e.g., radio waves, have long been understood and accepted as a natural phenomenon of fields. Now in QFT gravity is a field and, just as an oscillating electron in an antenna sends out radio waves, so a substantial mass moving back and forth will send out gravitational waves. But it didn’t take QFT to show this. Einstein also believed that gravity is a field that obeys his equations, just as the EM field obeys the equations of James Maxwell. In fact gravitational waves have been accepted by many physicists, from Einstein on down, who see gravity as a field.

    Curvature. But what about “curvature of space-time”, which many people nowadays say is what causes gravity? You may be shocked to learn that’s not how Einstein saw it. He believed that the gravitational field causes things, even space itself, to contract, comparable to the way motion causes contraction. In fact Einstein used this analogy to show the correlation between motion-induced and gravity-induced contraction: they both affect the way fields work together. It is this gravity-induced contraction that is sometimes called “curvature”.

    Evidence. The first uncovering of gravitational waves was done at LIGO, using an apparatus similar to Michelson’s and Morley’s. In both experiments the time for light to travel along two perpendicular paths was examined, but because the gravitational field is much weaker than the EM field, the distances in the LIGO apparatus are much more substantial (miles instead of inches). Another difference is that while Michelson, not knowing about motion-induced contraction, anticipated to see a shift (and found none), the LIGO staff used the known gravity-induced contraction to view an alteration when a gravitational wave passed through.

    Fields of Color: The theory that escaped Einstein explains Quantum Field Theory to a lay audience, without any mathematics. If you want to learn more about gravitational waves or about how Quantum Field Theory addresses the paradoxes of Relativity and Quantum Mechanics, read Chapters 1 and 2, which can be seen free at