Speaker Name(s): Alain Aspect, PhD, Laboratoire Charles Fabry de l’Institut d’Optique, Palaiseau, France
Description: Is light a wave or a particle? After many centuries of debate, involving giants such as Newton, Huyghens, Young, Fresnel, Maxwell, Einstein, the final answer of quantum mechanics is: Both. Wave-particle duality is at the root of the quantum revolution that started at the beginning of the 20th century, but explaining that weird concept is a difficult challenge. Most textbooks on quantum physics start with a description of an “experiment” to demonstrate it – an experiment that was not realized with photons before 1985. An even more fascinating version of that “thought experiment” – the “delayed-choice experiment” proposed by J.A. Wheeler --has been recently turned into a real experiment. We will present that experiment, which in the words of Richard Feynman, stresses one of the big "quantum mysteries.”