The Bhatnagar Prizes are given to scientists below 45 years of age, for their outstanding scientific contributions made primarily in India during the last 5 years preceding the year of the Prize. The SSB Prize comprises a citation, a plaque and a cash award of Rs.5,00,000/- (Rupees five lakh only), and are given to the recipients by the Prime Minister of India.
How complex concepts in Physics like Quantum field theory and giant concept of string theory can be milked in two hours of great oratory and generate persistent curiosity in the young, old research scientists is reflected from the presentation of Dr. Gopakumar deleivered at Tata Institute of Fundamental Research on 7th Sept. 2009. This year`s one of the winner of Shantiswaroop Bhatnagar award winner was there to present his passionate research as a part of commemorating birth centenary of Dr. Homi Bhabha.
At the outset he greatly focussed on principles of Physics embodying our ability to discern regularities amidst complex behaviour. This according to him, is remarkably capturable in precise mathematical language. Thus his belief in these principles seemingly able to continue to do so as we widen the scope of these laws though sometimes to do so requires conceptual and mathematical reorientation.
Jumping on the gravity, he tried to explain how gravity is the most ubiquitous force in nature. It is common knowledge that Newton’s law of gravitation the first “universal” law. However, he says, it has a certain range of validity and these laws break down under two different sets of extreme circumstances. What are these circumstances? “These are not applicable when objects move very fast (e.g. Pulsars) and also not relevant when the density becomes large (e.g. at the centre of galaxies).
Dr. Gopakumar further elaborated the evolution of the falsification of the Newton`s theories. Einstein succeeded in (partially) overcoming these limitations. His description of gravity applicable at high velocities (relativistic). It is also true for moderately high densities (e.g. neutron stars). This was accomplished this not just by tweaking Newton’s Law a bit. This as Dr. says radically overhauled the very framework for describing gravity. Einstein tied up the description of gravity with the geometry of space and time! Spacetime is no longer a passive stage for the drama of physical events. It becomes an active participant - responding to its contents.
He was teaching about ‘Gravity and Geometry’. Einstein’s theory is in a very different mathematical framework from Newton’s. In terms of a metric measurements of distance and curvature of spacetime; Einstein’s equations determine in terms of the matter/energy. This, remarkably enough, reduces to Newton’s law for low densities and velocities.
Then suddenly he introduced few doubts and questions like these: “Physical reality is QM’cal - classical measurables have statistical outcomes. Is spacetime a statistically averaged notion? How can we sensibly talk of quantum fluctuations of the metric? How do we reconcile Einstein’s picture with Quantum Mechanics? ” As he explains further, limitations of Einstein’s Law lead to the breakdown of Einstein’s description as you enlarge its scope again under two sets of limiting circumstances especially at very short (“planckian”) distances and at ultra-high densities. The equations themselves exhibit the breakdown - develop singularities.” Thus he manages to conclude that the need for a description that overcomes these limitations will be fulfilled by a Quantum theory of Gravity and scientists need Quantum. Gravity to investigate the birth of the universe or understand black holes.
Eventually Dr. Gopakumar names String Theory as ‘The Reluctant Radical’. Because String Theory originated as a “conservatively radical” modification of Quantum Field Theory(Q.F.T.) considering the Quantum dynamics of extended objects. This has to be understood in the context of delicately spun framework which is highly constrained - more so than Quantum Field Theory. String Theory showed early promise in addressing some of the difficulties QFT had with respect to gravity.
Recent interest in string theory is generated by variety of applications of theoretical insights scientists are getting. According to Suresh Kumar S., Scientist at NIIST , Trivendrum says1 that the same string-theory concepts used to describe black holes can help explain the behavior of electrons in a superconductor or metal. It has been used for explaining the strong nuclear forces involved in a quark–gluon plasma, and has become a competitor for the more favored QCD theories. Multi-dimensional space, with the extra dimensions being coiled in the ordinary three dimensioned case. Under high energy conditions these express themselves. Holographic principle applies in the reverse situation of extension to cooler or less energy intense situations :information contained in a higher dimension can be embedded in lower dimension. Possibility of certain material configurations and compositions under particular conditions causing holographic effects as above is being studies, so that a higher dimensioned phenomenon is morphed onto a lower dimensioned domain.
For decades researchers have tried to wrest testable predictions from string theory, the leading candidate for a more fundamental understanding of the universe.2 Now physicists say they have used one of the most sophisticated pieces of string theory to predict properties of the ultradense matter created in an atom smasher in Long Island, N.Y. If confirmed, however, the prediction would not offer evidence for string theory, which requires the existence of extra dimensions of space full of higher-dimensional stringlike objects and other widgets. Instead, it would establish that some of string theory's mathematics could be used to study the forces at work inside an atom's nucleus.
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1http://www.nature.com/news/2009/090719/full/news.2009.699.html
2http://www.scientificamerican.com/article.cfm?id=a-prediction-from-string-t
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