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?
Read the full explanation
Understanding Double Slit Experiment
In the double-slit experiment, a beam of particles (like photons or electrons) passes through two slits and hits a screen. When no one is watching, it creates an interference pattern—stripes of light and dark—suggesting wave behavior. But when you try to observe which slit each particle goes through, the pattern changes to look like individual particles passing through one at a time.
A deeper explanation
The experiment reveals that quantum entities can behave both as particles and waves. When not observed, they act like waves, spreading out and interfering with themselves to form a pattern. However, when measured or observed, their wave-like behavior collapses into particle-like behavior. This phenomenon is called the 'observer effect' and highlights the fundamental role of measurement in quantum mechanics.