Experimental Arrangement

An experiment very similar to one done by Young is illustrated in the diagram. A laser is located about two meters from a sheet of white paper taped to a wall. With the room as dark as possible, the laser is aimed so that its beam is perpendicular to the paper. If you do this experiment, never look directly into the beam coming from the laser. Then a slide with two very small, closely spaced slits is placed in the path of the laser beam, also perpendicular to the beam.