Quantum

Double Slit Lab

Send particles through two slits and watch interference emerge.

Watch an interference pattern form

Waves and detections

Change the wavelength or slit spacing. Compare probability intensity with individual detections. Flight markers are schematic.

Live measurements

booting...

Detection record

particles detected: 0

Change the conditions

Shape the experiment

de Broglie wavelength = 18 model units slit separation d = 90 model units slit width a = 14 model units Screen distance LOpen slits

Coherence & model limits

Path coherence

Coherence 1 gives full interference; 0 adds independent slit probabilities. A perfect which-path detector sets coherence to zero. Field and counts use the same finite-aperture Fresnel model. This is paraxial propagation, not a full 2D Schrödinger solver. Distances are model units; the apparatus diagram compresses horizontal distance. Counts are conditioned on reaching the visible screen.

fire rate WHICH-WAY DETECTOR at the slits show expected counts

TRY THIS

Turn on particle mode and auto-fire. Let a pattern build before enabling the which-way detector.

What you are seeing

Watch an interference pattern form

Compare the distribution of detections with and without which-way information.

An educational interference model. Acquiring which-way information involves a physical interaction; conscious observation is not required.