String theory: Understanding unified forces of nature
MUMBAI: The much talked subject currently in the corridors of the Tata Institute of Fundamental Research (TIFR) here is the "string" that unifies all natural forces as the scientists are looking forward to the international conference 'Strings 2001' in January next.
String theory aims at understanding the "theory of everything", i.e. forces of nature that work on different frequencies in harmony with each other, the scientists said.
Just like musical strings, this basic string can vibrate, and each vibrational mode can be viewed as a point-like elementary particle, just as each musical string is perceived as a distinct note.
One of co-ordinators of the forthcoming conference, Prof Sunil Mukhi said, "string theory is the most promising example of the unified theory. We are not yet sure that it correctly describes nature, but broadly describes a world similar to ours, and is endowed with beauty and consistency to an astonishing degree."
Scientists, making attempts for the last four decades to unravel the integrated working of various forces, succeeded in 1970s succeeded in understanding the unifying force of electromagnetism and the weak nuclear force of nature.
Experimentally, just four basic forces in nature are known -- electromagnetic force, gravitational force and two invisible "nuclear forces" --weak and strong.
Some of the implications of string theory are evident in blackhole physics, in cosmology and early universe and in scattering of elementary particles in accelerators, but many important details were yet to be worked out, Mukhi said.
Prof Spenta Wadia of TIFR said the string theory was mathematically well defined only in 10 dimensions. "On the other hand, we observe only four dimensions of the universe-- (three dimensions of space and one of time). However, depending on the magnification used by the observer, extra dimension could become visible", he said.
String theory has also a very precise notion of "duality" where very small distances, that can be much smaller than even the nucleus are equivalent to very large distances of the order of size of universe, according to another co-ordinator of the conference, Prof A Dabholkar. (PTI)