Classical Waves
Classical waves are emitted at the source and arrive at the detector only if they pass through the slits.
Key features:
- detector measures the energy carried by the waves. eg for water waves, the energy at the detector is proportional to the square of the height of the wave there. The energy is measured continuously.
- The energy of the wave at a particular point (x) with both slits open (I12) is NOT just the sum of the energy of the wave when only the top slit is opened (I1) and the energy of the wave when only the bottom slit is opened (I2). An interference pattern is seen, formed by the superposition of the piece of the wave which passes through the top slit with the piece of the wave which passes through the bottom slit.