Strangest Experiment Ever (Double-Slit Experiment)

Transcript

When a laser emits beams of light particles called photons at a screen with two slits, you’d expect to see two strips to correspond with the two slits. Instead, we see a pattern of light and dark bands.

This suggests that light behaves like waves that pass through both slits simultaneously, interfering with each other to create the pattern on the second screen. However, when scientists used a measuring device to observe the slit that each photon passed through, the interference pattern disappeared,

and two strips appeared. The act of observing which slit it went through changed the behavior of the photons! No one knows why observing a particle causes its behavior to change.