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.
The program recognizes the following commands:
| B | Beam mode. The beam of particles does not pass through a double slit. Each time you press 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. |
| 2 | Two-slit mode. 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 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. |
| Q | Quit program. |
| ? | Help. These commands are listed. |