I think the Double-slit electron diffraction is my favorite – “Robert P. Crease, a member of the philosophy department at the State University of New York at Stony Brook and the historian at Brookhaven National Laboratory, recently asked physicists to nominate the most beautiful experiment of all time. Based on the paper of George Johnson in The New York Times we list below 10 winners of this polling and accompany the short explanations of the physical experiments with computer animations.” Link.
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