law of reflection

American  

noun

1. the principle that when a ray of light, radar pulse, or the like, is reflected from a smooth surface the angle of reflection is equal to the angle of incidence, and the incident ray, the reflected ray, and the normal to the surface at the point of incidence all lie in the same plane.

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Usage

What is the law of reflection? While it may sound like a form of meditation, the law of reflection is a principle about what light does when it hits a perfectly smooth surface, like a mirror. The law states that light will bounce off such a surface at the exact same angle it hit that surface at.

Example Sentences

These are the law of reflection, for situations in which light bounces off matter, and the law of refraction, for situations in which light passes through matter.

From Textbooks • Aug. 12, 2015

The law of reflection is illustrated in Figure 25.3, which also shows how the angles are measured relative to the perpendicular to the surface at the point where the light ray strikes.

From Textbooks • Aug. 12, 2015

Figure 25.3 The law of reflection states that the angle of reflection equals the angle of incidence— θr = θi .

From Textbooks • Aug. 12, 2015

Figure 27.6 shows how a mirror reflects an incoming wave at an angle equal to the incident angle, verifying the law of reflection.

From Textbooks • Aug. 12, 2015

We have illustrations of this law of reflection in the case of water waves striking against a breakwater, or a sound wave striking against the wall of a room.

From Aether and Gravitation by Hooper, William George