Raman Research Institute - Achievements

Achievements

Despite its budgetary and infrastructural constraints, scientists working under Raman did some path-breaking work. For instance, S. Pancharatnam, who joined the institute in 1954, discovered a fundamental quantum optic effect, independent of Raman. This work, according to Jayaraman, was "the most outstanding original piece of research that came out of RRI at that time."

This discovery proved for the first time that geometric phase exists in optics. But this work was not known to the world till similar discovery was made by scientists elsewhere about two decades later. Subsequently, RRI could convincingly prove that Pancharatnam discovered this long ago and today "this phase is called Pancharatnam Phase world over," said Madhusudana. Pancharatnam unfortunately did not live long enough and his brilliant career was cut short when he died in 1969 while in Oxford.

The institute also houses Raman's prized collection of gems, crystals, minerals, and rock specimens from all over the world. Raman, who was fascinated by the colours of the biological kingdom, also had a veritable collection of stuffed birds, beetles, and butterflies in his museum. It is said that Raman used to take a lot of pride in showing off his precious collections to distinguished visitors to the institute. During Raman's time, many celebrated scientists from other countries paid a visit to the institute. Among them were: J. D. Bernal, E. C. Bullard, P. M. S. Blackett, C. G. Darwin, P. A. M. Dirac, G. Gamow, J. B. S. Haldane, Linus Pauling, C. F. Powell, L. Rosenfeld, G. Wentzel and Norbert Wiener.

One of the current research priority areas of the institute is liquid crystals. This has been an active area of research at the Raman Research Institute for nearly three decades. The research programme covers a broad spectrum of activities ranging from the synthesis of new liquid crystalline materials to display electronics. Discoveries of the columnar phase formed by disc-like molecules and pressure induced mesomorphism are two of the early significant contributions made by the liquid crystal group. "Out of 36 liquid crystal materials discovered world over three were from this institute," said Prof. Madhusudana. Among them are two new liquid crystalline phases, namely the undulating twist grain boundary C phase and the biaxial smectic A phase.

Techniques developed for driving passive matrix liquid crystal displays at the institute are now being widely used. In recent years the liquid crystal group has been working on electrochemical aspects of surface science and on other soft materials like surfactants, polymers, and on the physics of biological systems

Astronomy and astrophysics has been another strong area of research for RRI. According to Prof. Madhusudana, this division accounts for the maximum number of faculty and research students of the institute. Over the last 20 years, it has been carrying out observational programmes in radio astronomy, covering almost the entire radio spectrum. Besides having a millimetrewave telescope of 10.4 metre diameter on the campus, RRI has set up a decametrewave Radio telescope at Gauribidanur, about 80 kilometres away from Bangalore, jointly with the Indian Institute of Astrophysics (IIA), Bangalore. This is one of the few largest telescopes that operate at the wavelength of 10 metre and is being used by RRI scientists to study radio emission from various types of celestial objects such as the Sun, Jupiter and similar radio sources in Milky Way and other galaxies. Other radio telescopes that are being used by RRI scientists for observations are Ooty Radio Telescope, at Ooty, and Giant Metre wavelength Radio telescope (GMRT), near Pune, both set up by the Tata Institute of Fundamental Research (TIFR). RRI also played an active role in building a low-frequency radio telescope in Mauritius jointly with the University of Mauritius and IIA.

The major astronomical investigations pursued at the Institute can be broadly classified into the following categories: (i) Neutron Stars and Pulsars; (ii) cosmology; (iii) Diffuse matter in space; and (iv) Radio Sky Surveys.

The theoretical physics activity in the institute has centred around relativity and gravity, quantum theory, and optics. The current activity in gravitation centres around two themes, gravitational radiation and quantum gravity. Gravitation is known to be the weakest of all known forces of nature, but it dominates all structure and motion on the astronomical scale because of its attractive universality, its long range and the fact that matter on the large scale is essentially neutral. The correct theory of gravitation is now believed to be Einstein's General Theory of Relativity. One of the fundamental predictions of General Theory of Relativity is that of gravitational waves — waves of distortion of spacetime itself - propagating at a finite speed of light. This replaces the Newtonian gravitations forces which was instantaneous. Such waves are expected to be emitted when, for example, two massive inspiralling stars tend to coalesce under their mutual gravitations attraction. Accurate calculation of this gravitational radiation — its waveform — has been one of the major research programmes of the theoretical physics group at the institute. Their work is expected to be a crucial input towards its eventual detection.

Another major activity of the theoretical physics group has been in studying propagation of light waves in certain types of liquid crystals and minerals and their associated polarization phenomenon. RRI has been a pioneer in this field of study which was actually initiated by one of Raman's research students, Pancharatnam.