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How does reflection change the path of light?

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A horizontal gradient bar displays the visible light spectrum from violet to red, labeled with corresponding frequency in terahertz, wavelength in nanometers, and photon energy in electron volts. — light When white light is spread apart by a prism or a diffraction grating, the colours of the visible spectrum appear. The colours vary according to their wavelengths. Violet has the highest frequencies and shortest wavelengths, and red has the lowest frequencies and the longest wavelengths.

Reflection is the abrupt change in the direction of a light wave when it strikes the boundary between different media. When light encounters a smooth surface, it follows the law of reflection, which dictates that the angle of the reflected ray is equal to the angle of incidence. Both of these angles are measured relative to a line perpendicular, or normal, to the reflecting surface.12

The reflected ray, the incident ray, and the normal all lie within the same plane of incidence. While regular reflection occurs at smooth, plane boundaries—such as those found in mirrors—reflection at rough or irregular boundaries results in diffuse scattering. It is important to distinguish this from refraction, which occurs when light transmits into a second medium and changes its path according to Snell’s law.32145

Would you like to learn more about how different types of mirrors, such as concave or convex surfaces, specifically alter the path of reflected light?