In this section we describe in a reader-friendly fashion the 2-slit experiment. We derived the inspiration from the Nobel Laureate Richard Feynman's presentation, as contained in the first chapter of his “The Feynman Lectures on Physics Part III", the volume devoted to Quantum Mechanics. We are thus moving through the steps shown in the following scheme. We will analyze and compare the behaviour exhibited by different systems, i.e.
1) material particles (little balls)
2) waves (in particular waves produced in water)
in the two-slit experiment, devised by Thomas Young with the purpose of demonstrating the wavelike behaviour of light (an experiment which also appears in the list of the 10 most beautiful experiments according to the Physics World poll). Other descriptions of the experiment, also Feynman inspired, are to be found in:
Further descriptions can be found in the link section and in the references section.
The rest of the content entails a more in-depth educational treatment of the theme waves and interference. We advise to read this before approaching the part concerning waves, since it deals with concepts necessary for the comprehension of the different steps of the experiment.