Physics
Double Slit Experiment
Quick fact
The double-slit experiment was first performed with light by Thomas Young in 1801 and later extended to electrons, showing that even single particles can create interference patterns.
Why this is interesting
Imagine a single particle of light, or photon, passing through two narrow slits in a wall. What happens? Does it go through one slit, like a bullet, or both at once, like water waves?