The Particle Illusion: A Closer Look at Feynman's Double-Slit Paradox

Abstract

In 1963, Richard Feynman gave a memorable lecture on quantum mechanics' strange and non-intuitive nature. Using the example of two-slit self-interference, he showed how quantum entities such as electrons appear to traverse two passages at once. While Feynman's analogy beautifully captures the strangeness of quantum behavior, it leaves open the definition of "particle." A few additions to his thought experiment provide another insight: Experimentally, the only definition of a particle possible is that it is a sequence of expanding quantum waves punctuated by minute exchanges of momentum and energy that relocalize and restart the wave. This article uses Dibyajyoti Das's beautifully done adaptation of Feynman’s thought experiments to precisely assess what it takes to make an electron act like a bullet.