Defining Refraction and Diffraction
Wave refraction is the bending of waves as they pass from one medium into another, caused by a change in their speed. In contrast, wave diffraction is the bending and spreading of waves as they encounter an obstacle or pass through an opening, effectively bending around corners.
Underlying Principles
Refraction occurs because the wave's speed changes in the new medium, causing a shift in its direction, a principle governed by Snell's Law. Diffraction, however, is explained by Huygens' Principle, which states that every point on a wavefront acts as a source of tiny wavelets, allowing waves to spread out beyond geometric shadows.
Everyday Examples
A common example of refraction is a straw appearing bent when placed in a glass of water, due to light slowing down and bending as it enters the water. Diffraction can be observed when you hear sound from around a corner, or when light passing through a narrow slit creates a spread-out pattern rather than a sharp image.
Importance and Applications
Understanding refraction is crucial for designing optical lenses, fiber optics, and telescopes, enabling us to correct vision or transmit data. Diffraction is fundamental to technologies like holography, X-ray crystallography for determining molecular structures, and designing effective antennas for radio communication.