TWOSLIT

Double Slits and Particles

This animation shows what happens when particles are sent one at a time through a double slit. The particles can be either photons or electrons.

beam The beam of particles does not pass through a double slit. Each time you press fire (or the space bar), a particle is sent down the beam and the position where it hits the screen is indicated by a white dot. If you hold down the space bar, the particles will come more frequently.
double slit The beam of particles passes through a pair of vertical slits. This causes the particles to be diffracted horizontally. As in the beam mode, each time you press fire (or the space bar), a particle is sent through the double slit and the position where it hits the screen is indicated by a white dot. If you hold down the space bar, the particles will come more frequently. As the position of many particles are accumulated on the screen, a double-slit interference pattern becomes apparent.