Mega Science Project India Will Soon Be Joining a Global Network of Gravitational Wave Observatories
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Y. B ALA MURALI KRISHNA Article Gravitational Wave Feature Observatory Mega Science Project India will soon be joining a global network of Gravitational Wave Observatories. (GWO)” in collaboration with the United involved sanction of Rs.1260 crores to be States of America as part of a global spent over the next 15 years (2012-2027). VEN as top particle physicists the network. The prestigious project, mooted by world over recently celebrated the The proposal for the $290 million the Consortium of Indian Initiative in Ediscovery of the Higgs boson at dollar facility is pending approval of the Gravitational Wave Observations, Geneva’s CERN facility, India is geared to Government of India. The Indian scientists codenamed IndIGO, aims at construction add a new dimension to 21st century are confident that the Union Cabinet will and subsequent fifteen year operation of astrophysics by setting up a state-of-the- soon clear the ‘mega-science project’ that an advanced interferometric gravitational art “Gravitational Wave Observatory wave detector in India, called LIGO-India, in collaboration with USA’s LIGO What are Gravitational Waves? Laboratory. We often hear of X-rays, Radio waves, Alpha-rays, Gamma-rays, Micro-waves, “We are confident that India joins the Ultra-violet rays and Light-rays from different sources including the sky. All US-led global network of GWOs to further of them, in the language of science, are known as electro-magnetic waves, promote astronomy of the 21st century. emitted by electric charges in motion that have several applications in day- India could play a pivotal role as a partner to-day life, medicine, electronics and even telecommunications including of the global network as we are on the television and radio networks. threshold of a new era of gravitational wave Another type of waves, known as “gravitational waves” (GWs) akin to the astrophysics,” says Dr. Stan Whitcomb, chief electro-magnetic waves, have been detected from the Universe. The GWs are scientist of the LIGO Lab. emitted by gravitating bodies in motion, such as two ‘black holes’ spiralling He was interacting with the author after towards each other in a binary orbit in the cosmos. visiting India recently as part of a five- Gravitational Waves are extremely difficult to detect, and although they member high-level US delegation to find were predicted about one hundred years ago, till today they have not been out whether India is keen to take seen in experiments, physicists say. advantage of the global network. There is irrefutable indirect evidence that they do exist – this evidence Other members of the US’s LIGO group comes from the Nobel Prize winning discovery that the compact binary orbit delegation included Dr. Dave Reitze (LIGO of a pair of stars is shrinking due to the emission of gravitational waves, Director), Dr. Jay Marx (LIGO ex-Director), precisely as predicted by General Theory of Relativity. Dr. David Shoemaker (Advanced LIGO The experimental discovery of gravitational waves will open an Project Leader) and Dr. Fred Raab (Head, extraordinary new window in astronomy, what is often known as gravitational LIGO Hanford Observatory). wave astronomy. Just as astronomers have been studying the Universe for “We visited IPR (Ahmedabad), RRCAT centuries using electromagnetic waves, they will in the future be able to (Indore) and IUCAA (Pune). At each study it with gravity waves. location, we met with a number of IndIGO Great experiments are currently in progress worldwide, using colleagues for discussions about the LIGO ‘Gravitational Wave Detectors (GWD)’, to find gravitational waves. technical requirements, and visited a SCIENCE REPORTER, NOVEMBER 2012 44 Feature Article Dr. Bala Iyer, Chairman, IndIGO Council with US’s LIGO-Lab Chief Scientist Dr. Stan Whitcomb (right) number of laboratories to see the Indian ready by 2017, is under construction in an holes, tight constraints on physics at nuclear capabilities in the relevant areas,” he said. underground Kemijoki mine in Japan as densities, insight into the mechanism of Asked about the site selection for the part of the network. short gamma-ray bursts, highly accurate mega-science project in India, he said, measurements of the Hubble flow out to the delegation reviewed some general z ~ 0.2, tests of strong-field relativity, information concerning the Indian Significance of GWO measurements of the speed of geological formations, and discussed the Prof. Bernard F. Schutz from the Max Planck gravitational waves, constraints on extra steps that would be needed to assess and Institute for Gravitational Physics, Albert scalar gravitational fields, and tests of the validate any proposed site. Einstein Institute, Potsdam, Germany, who cosmic censorship hypothesis,” Prof. Schutz There are two detectors in the USA had earlier interacted with Indian claims. under LIGO Laboratory while the third one astrophysicists and cosmologists in Goa Further, sensitivity improvements, and GEO is in Hannover (Germany) now under avers that study of the Gravitational Waves then the construction of third-generation upgrade with pioneering advanced is the astronomy of the 21st century. detectors like the Einstein Telescope, offer optical technologies. An advanced LIGO “Advanced ground-based detectors much more than this. The opening of the version of the VIRGO with advanced will almost certainly make the first low-frequency window with a space- seismic isolation system is also operational detections of gravitational waves within the based detector like LISA or eLISA will bring near Pisa in France with US collaboration next few years. With a worldwide network all our galaxy’s compact binary systems since May 2007. of five sensitive detectors, we will be able under scrutiny and will reveal how the A $100-million Large Cryogenic to count on spectacular science returns: massive black hole population of the Gravitational Telescope (CGWT), to be mass functions for neutron stars and black universe got started and grew. The ultra-low frequency window explored by pulsar timing can give further Completing the Global Network information about the supermassive black ○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○ hole population. These are the scientific outcomes we can predict and what we can’t predict will be guaranteed to be GEO Virgo LIGO even more interesting! LCGT Planned detectors are very close to IndIGO on the Move co-planar-- Meanwhile, chairman of the IndIGO not optimal for all-sky coverage Consortium Council Dr. Bala Iyer says the consortium is going ahead with identifying suitable seismically free sites for the Large increase to science capability proposed GWO. from a southern node in the network “Various sites would be studied for various parameters before shortlisting them LIGO-India even as we are anxiously awaiting the clearance of the project by the LIGO-G110127201 ICGC, Goa Government of India,” he said. “The An artistic view of the global network of GWOs indications so far are positive.” 45 SCIENCE REPORTER, NOVEMBER 2012 Feature Article For the LIGO-India project, the US and its international partners (UK, Germany and Australia) will contribute complete design and hardware of the detector worth $140M (Rs 650 Crores). Consortium is going ahead with identifying suitable seismically free sites Inside view of LIGO for the proposed GWO. The project would go a long way in facilitating national and international is considered to be an essential element providing job opportunities for young Indian collaboration. in the global network of detectors. astrophysicists and cosmologists besides “The task of constructing this very paving way for high-end research with sophisticated detector at the limits of IndIGO: Status international collaborators. Some Indian present day technology is facilitated by Interestingly, the IndIGO Consortium has scientists have already been undergoing the amazing opportunity offered by the become a member of the Gravitational training at the US LIGO Laboratory. LIGO Laboratory and its international Wave International Committee (GWIC) and partners to provide the complete design of the LIGO Scientific Collaboration (LSC). Dimensions of LIGO-INDIA and all the key components required to LSC membership gives the IndIGO scientists The proposed Indian detector is a 4-km build the detector as part of the access to detector data of LIGO-USA and arm-length Michelson Interferometer with collaboration,” Dr. Tarun says. the opportunity to be part of the potential Fabry-Perot enhancement arms, and aims Indian scientists will build the detector first detection of GW. to detect fractional changes in the arm- as also the entire infrastructure including The US National Science Foundation length smaller than 10-23 Hz-1/2, says the ultra-high vacuum vessels and tubes (Advanced LIGO’s main sponsor) has IndIGO spokesman Dr. Tarun Souradeep. required to house the interferometer at a already given approval to study the The minimum size requirement for the suitable, gravitationally and seismically feasibility for LIGO-India. At the same time, detector is a L-shaped site of arms 4 km quiet site in India. IndIGO and the LIGO the foundation board is expected soon to and width 150 m. This is about 300 acres. Laboratory will work together in realizing give formal approval for the collaboration. The area should be seismically quiet and the Indian node (LIGO-India) of the The science case for LIGO-India is free of anthropogenic noise but close international gravitational wave detector compelling, observes the NSF. enough