Prof. Ennakkal Chandy George Sudarshan is considered as one of the greatest physicists India ever gifted to the world. Prof. Sudarshan was born in 1931 at Kottayam, Kerala State, India. After his initial studies at C. M. S. College, Kottayam he joined at Madras Christian College, Chennai for B.Sc.(Hon’s). He received his M A in Physics from the University of Madras in 1952. He joined at Tata Institute of Fundamental Research, Mumbai to work with Prof. Homi J. Bhaba on Cosmic Ray Showers (1952-1955).
In 1958 he received a Ph.D. in Radio Activity from Rochester University , New York.
He has taught at TIFR, University of Rochester, Syracuse University, Harvard University, University of Berne and Indian Institute of Science. Currently, he is a professor of Physics at The University of Texas, Austin, USA.
Prof. Sudarshan's great contribution to Physics is the formulation of "Tachyons" (1962), particles that travel faster than light. Theory of tachyons is in a direct contradiction with Einstein's Theory of Relativity. Special Relativity says that nothing can travel faster than light. All the massless particles (like photons, gravitions) must travel at the speed of light. All the massive particles (protons, electrons etc) must travel with a speed less than that of light. If a massive particle travels faster than light, it must go backward in time. The minimum speed that a tachyon can have is the speed of light. When a tachyon loses energy it gains speed ! Consequently, when a tachyon gains energy, it slows down. Relativity can accept faster than light phenomenon in certain situations. For example, space can expand in faster than light speed (Inflationary Cosmology is based on this idea). Quantum field theory (a combined theory of quantum mechanics and relativity) allows particles to move faster than light. But information cannot travel faster than light as it violates causality. That means communication at faster than light is not allowed in any of the present consistent theories.
Tachyons were first proposed by a German physicist Arnold Sommerfeld (1961), and later Gerald Feinberg (Columbia University 1967) named them as tachyons. The word tachyon derives from the Greek word tachus, meaning "speedy."