Bell’s theorem: rejection of Einstein’s concept of local-realism

The experimental works on which Nobel Prizes have been awarded this year, involve a very important result discovered by John. S. Bell in 1964. This is famously known as Bell’s theorem and has been considered to be the ‘most profound discovery of Science’ by some physicists. Bell’s theorem shows that quantum world is not compatible with the twin concepts of local-realism propounded by Einstein. Experiments establish that nature is indeed incompatible with local-realism. In this talk we shall discuss the work of John Bell in a simplest possible way. In particular, no expertise in quantum mechanics is needed to understand the essence of Bell’s theorem.