Fresnel's equations

Fresnel's equations describe how light behaves when it hits the boundary between two different materials, like air and water. They explain how much light is reflected and how much is transmitted (passes through) at that boundary, depending on the angle of incidence and the properties of the materials. These equations are important in optics and help us understand phenomena like glare on water surfaces or why we see reflections in windows. Essentially, they quantify the interplay between reflection and refraction (bending of light) in various situations.