Diffraction

Waves go behind the corners, the legendary ripple tank finally works. No way in real world...

Diffraction patterns are due to interference of different waves, in other words the superposition of the waves.

Try that. Pick up 4 points of minimum intensity and another 4 of maximum intensity. What are the path differences of the two waves in different cases?

• The constructive interference (max intensity) takes place when the path difference is a multiple of the wavelengths.
• How about destructive interference?

There are two loudspeakers in the opposite ends of the room sending 440 Hz. Consider you walk on the line joining the loudspeakers. Describe the sound you hear. What is the minimum distance between the points you do not hear anything at all?