Final answer:
Diffraction and wave interference explain why light passing through a round hole creates a specific pattern. Waves bend and overlap to form regions of constructive and destructive interference, resulting in a fringe pattern on a screen.
Step-by-step explanation:
When light passes through a round hole, it produces a pattern due to diffraction and wave interference. Diffraction occurs because waves bend around the edges of an aperture, as shown by Huygens's principle. The subsequent fringe pattern is a result of the superposition of diffracted waves, leading to regions of constructive and destructive interference. Constructive interference enhances wave amplitude where wave peaks coincide, whereas destructive interference reduces it where peaks and troughs coincide. This can be comparable to two stones dropped in water creating ripples that intersect; where crests meet, the waves build up (constructive), and where a crest meets a trough, they cancel out (destructive).
The pattern created by light passing through a round hole can be understood in relation to phenomena like double-slit interference, where similar principles apply, but with unique patterns due to the geometry of the aperture. These patterns are not explained by the particle nature of light or by refraction of light, as they are distinct from diffraction and interference effects. While light exhibits particle-like behaviors under certain conditions, the patterns observed in these experiments are indicative of its wave characteristics.