Increase for the double gap
Experiments using a triple slit instead of the classic two-slit variant reveal subtle and mostly overlooked aspects of quantum mechanics.
The winner of the Nobel Prize in Physics, Richard Feynman, thought highly of the double-slit experiment: "The whole secret of quantum mechanics" resides in it. In the experiment first proposed by British polymath Thomas Young in 1801, light hits a wall with two slits. Behind it, it falls onto a screen and creates an interference pattern, i.e. alternating light and dark stripes. Such an image can only arise if vibrations amplify or cancel each other out. Young's experiment seemed to prove that light is a wave and not a particle.
But that's only half the story. A century later it became clear that electromagnetic radiation, despite its wave character, is transmitted in small portions. Photons are responsible for this, i.e. particles. Physicists finally succeeded in sending these individually to a double slit. But even in this case, a pattern gradually emerges, as if the photons had interfered with themselves. It gets even weirder once you use a detector to determine which path each one takes. Then the pattern disappears and you get two lines on the screen. Again, that would be expected of particles and not waves-as if the act of measurement had changed the nature of light.
Because the experiment is so simple in principle and reveals the basic paradoxes of quantum mechanics, it is probably one of the most fascinating approaches to the quantum world…
