BENGALURU:The Nobel prize for physics this year was announced on Tuesday for three US scientists who worked on a global project that discovered the phenomenon of gravitational waves, predicted by Einstein 100 years ago.In Bengaluru, scientists who have been working on gravitational waves for decades and have made major contributions to the discovery, rejoiced at the announcement.
Prof Bala Iyer, a theoretical physicist who was with the Raman Research Institute, Bengaluru became associated with research in gravitational waves starting in the 90’s. He says, “It’s a dream come true for people who are involved in the project. The Nobel prize comes as a recognition of the monumental work done. The scientists who got the Nobel prize were instrumental in training and mentoring people who ultimately became part of the project. It is a feeling of elation of being part of something so big.”
Prof Bala and his team of students contributed to developing theoretical models of the expected gravitational waves. “There are different aspects to the detection of gravitational waves.
One is the experiments which are very sensitive and another aspect is to develop theoretical models in order to detect weak signals and to understand the source of waves and the nature of waves.” Prof Bala and his team further worked on tests of gravity using gravitational waves observations.Prof Bala is currently visiting professor with the International Center for Theoretical Sciences (ICTS) and is principal Investigator of the IndIGO-LSC, a consortium of Indian institutes and scientists who are part of LIGO collaboration
Bala collaborated with researchers in France, to work on analytical modelling of gravitational waves from binary neutron stars and black holes. “In the early 90’s when the LIGO was funded, Kip Thorne (one of the three scientists who got the Nobel) called a meeting with all those involved in the field to consolidate global efforts for the project. This was the starting point of the Indian research on source modelling,” says Bala.
At the ICTS, a young research group led by P Ajith, a physicist at the institute and a member of the LIGO scientific collaboration since 2004, took the work of Bala Iyer’s group to another level. They married analytical mathematical calculations with large-scale supercomputer simulations and produced accurate models of the gravitational-wave signals expected from the merger of black holes. Such theoretical models are crucial for detecting weak gravitational-wave signals from the noisy data and to extract the properties of the astronomical source.Their work enabled the LIGO collaboration to estimate the properties of the “final black hole” that was produced by the merger of two black holes. They also developed one of the very first tests of Einstein’s theory using gravitational-wave observations.
“It is not a big surprise that this year’s Nobel went to three outstanding individuals who pioneered LIGO’s quest for the detection of gravitational waves. This is a landmark discovery in science, which also captured the public imagination worldwide,” he says.
‘Black Hole man’
Prof C V Vishveshwara, a black hole physicist from Bengaluru made major contributions to the study of black holes starting in the late 1960’s, long before the term “black holes” were even used. His third scientific paper was on the scattering of gravitational waves. One of the things detected by the LIGO was the quasinormal modes (that tells one about the properties of a black hole), something that Vishveshwara had written about in 1970. Sanjeev Dhurandhar, is another scientist who was in Bengaluru very briefly,and who made major contributions in data analysis techniques of gravitional waves along with Prof Bala Iyer.
A Nobel’s protege
P Ajith was a postdoctoral scholar at Kip Thorne’s research group at Caltech in USA from 2009 to 2013. “Kip Thorne’s research group at Caltech had a fantastic atmosphere. Apart from the great science, there were all kinds of discussions about “the movie” (what became Interstellar) that Kip was involved in making. The story was strictly secret; but according to rumors, the original story line started with LIGO detecting gravitational waves!”
The great Indian effort
In India as many as 70 scientists and 13 institutes such as the Inter-University Centre for Astronomy and Astrophysics, Pune, Chennai Mathematical Institute, Indian Institute of Technology, Chennai and Gandhinagar and others are part of the LIGO project.
The Fourth Wave
The LIGO detected its first direct gravitational wave two years ago. The two interferometers in USA was joined by the in third interferometer, the VIRGO in Italy. The first signal with all three interferometers was detected On August 14thkaming the possibility of pinpointing the locations of these sources much more accurate