What is the impact of a gap or obstacle on wave behavior?

When a wave encounters a gap or an obstacle, diffraction is the phenomenon that occurs. Diffraction refers to the bending and spreading of waves as they pass through an opening or around the edges of an obstacle.

This behavior is particularly noticeable with waves such as sound and light. For example, when sound waves travel through a narrow doorway, they spread out into the space beyond the doorway, which allows us to hear sounds even when we are not directly in line with the source. Similarly, light waves can spread out when they pass through a narrow slit, which can create patterns of light and dark fringes in experiments like the double-slit experiment.

Understanding diffraction is crucial because it demonstrates the wave nature of light and sound and illustrates that waves can propagate in ways that are not straightforwardly aligned with their direction of travel. This is in contrast to scenarios where waves could stop, reflect, or amplify, which do not accurately capture the characteristic behavior observed with gaps and obstacles.