Reflection, refraction, and diffraction are fundamental phenomena that occur when waves interact with different materials or obstacles. Let's look at each of them:
Reflection: Reflection refers to the bouncing back of waves when they encounter a boundary between two different media. When a wave reaches a surface and encounters a change in the medium, such as from air to water or from air to a mirror, a portion of the wave energy is reflected back into the original medium. The angle at which the wave approaches the surface (the angle of incidence) is equal to the angle at which it is reflected (the angle of reflection), following the law of reflection. This phenomenon is commonly observed with light waves reflecting off surfaces, but it applies to other types of waves as well.
Refraction: Refraction occurs when a wave passes from one medium to another and changes its direction due to a change in its speed. When a wave travels from a medium with one optical density (refractive index) to another with a different optical density, it bends as it enters the second medium. This bending is caused by the change in the wave's speed, which occurs because different materials have different speeds of wave propagation. The change in direction is determined by Snell's law, which states that the ratio of the sines of the angles of incidence and refraction is equal to the ratio of the speeds or refractive indices of the two media.
Diffraction: Diffraction is the bending or spreading of waves around obstacles or through narrow openings. When a wave encounters an obstacle or an aperture of comparable size to its wavelength, it undergoes diffraction. The wave spreads out, and new wavefronts are formed, creating a pattern of constructive and destructive interference. Diffraction can occur with various types of waves, such as light waves, sound waves, or water waves. The extent of diffraction depends on the size of the obstacle or aperture relative to the wavelength of the wave.
These phenomena play a crucial role in how waves interact with their environment and are fundamental principles in the study of wave behavior in physics and other scientific disciplines.