THE STRING THEORY

INTRODUCTION
String theory is a developing theory in particle physics which attempts to reconcile quantum mechanics and general relativity.

String Theory, sometimes called the Theory of Everything, is thought by some to be the unifying field theory Einstein sought before his death. String theory is the first mathematically sound theory that reconciles the world of the infinitesimally small, with the world we know at large. It unites Einstein’s Theory of Relativity with quantum physics and offers a potential explanation for the Big Bang.


What's string theory?

String theory posits that the electrons and quarks within an atom are not 0-dimensional objects, but rather 1-dimensional oscillating lines ("strings"), possessing only the dimension of length, but not height or width. The theory poses that these strings can vibrate, thus giving the observed particles their flavor, charge, mass and spin.

History of String Theory

Gabriele Veneziano, a research fellow at CERN (a European particle accelerator lab) in 1968, observed a strange coincidence - many properties of the strong nuclear force are perfectly described by the Euler beta-function, an obscure formula devised for purely mathematical reasons two hundred years earlier by Leonhard Euler. In the flurry of research that followed, Yoichiro Nambu of the University of Chicago, Holger Nielsen of the Niels Bohr Institute, and Leonard Susskind of Stanford University revealed that the nuclear interactions of elementary particles modeled as one-dimensional strings instead of zero-dimensional particles were described exactly by the Euler beta-function. This was, in effect, the birth of string theory. However, later experiments in the early '70s revealed that many of the theory's predictions were at odds with experimental data. As point-particle theory met success after success, string theory was left by the wayside by all but a few dedicated physicists.

String theorists explain that strings can be open or closed. Open-ended strings have one endpoint attached to the brane on which they reside, keeping matter contained within that brane. Our bodies are believed to be made from open-ended strings. This explains why we can’t reach into or interact with other dimensions. Close-ended strings, however, are like tiny rings, unattached to their brane, able to “leak” away from it; which brings us to gravity.

String theory and Einstein’s dream

Unification of the theory of gravitation, as given by Einstein’s general theory of relativity, and the theory of electromagnetism, as formulated by Maxwell, had been Einstein’s dream during the later part of his life. String theory, which is the subject of this article, is an attempt to realize this dream. However in many ways string theory attempts to go beyond Einstein’s dream. String theory attempts to bring all known forces of nature – not just gravity and electromagnetism – under one umbrella. It also tries to do so in a manner that is consistent with the principles of quantum mechanics – the theory that is necessary for describing the laws of nature at very small distance. Thus string theory is an attempt to provide an all-encompassing description of nature that works at large distances where gravity becomes important as well as small distances where quantum mechanics is important.