Answer:
Step-by-step explanation:
**Refraction** is a phenomenon in physics that occurs when a wave, such as light, changes direction as it passes from one medium (e.g., air) into another medium (e.g., glass or water) with a different optical density. This change in direction is due to the change in the speed of the wave as it moves from one medium to another.
When light waves transition from a less dense medium (lower refractive index) to a denser medium (higher refractive index), they slow down and bend toward the normal line (an imaginary line perpendicular to the surface). Conversely, when light waves transition from a denser medium to a less dense medium, they speed up and bend away from the normal line.
An everyday example of refraction is the way a straw appears to "bend" or "break" when partially submerged in a glass of water. This occurs because light traveling from the submerged portion of the straw through the water and then into the air undergoes refraction. The change in the direction of light at the air-water interface makes the straw appear disjointed at the surface of the water.
Refraction is also responsible for various optical phenomena like the formation of rainbows, the bending of light through lenses in eyeglasses, and the mirage effect in deserts, where distant objects appear displaced due to the bending of light as it passes through layers of air with varying temperatures.
In summary, refraction is a fundamental principle in physics that explains the bending of waves, such as light, when they transition between media with different optical densities.