Reflection of Light

Front

Normal Noun

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[nor-muhl]

Back

Normal

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An imaginary line that is perpendicular to a surface at the location where light strikes the surface.

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Example: The normal is an imaginary line (dashed) drawn at a right angle (90°) to a surface, like a mirror, where a light ray hits.

Front

Incident Ray Noun

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[in-si-dent ray]

Back

Incident Ray

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A ray of light that travels toward a surface and strikes it at a specific point.

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Example: This image shows an incident ray as the beam of light that travels through the air and strikes the boundary of the water.

Front

Reflected Ray Noun

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[ri-flek-ted ray]

Back

Reflected Ray

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A ray of light that has bounced off a reflective surface after striking it.

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Example: This diagram shows parallel light rays bouncing off a smooth surface, with arrows indicating the direction of the reflected rays moving away from it.

Front

Specular Reflection Noun

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[spek-yuh-ler ri-flek-shun]

Back

Specular Reflection

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Reflection from a smooth surface where parallel incident light rays reflect in a single parallel direction.

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Example: This diagram shows a light ray hitting a smooth surface. It labels the incoming 'incident ray,' the outgoing 'reflected ray,' and shows they reflect at equal angles.

Front

Diffuse Reflection Noun

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[di-fyoos ri-flek-shun]

Back

Diffuse Reflection

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The scattering of light off a rough surface, where parallel incident rays are reflected in various different directions.

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Example: When parallel light rays hit a rough, uneven surface, they scatter and reflect in many different directions.

Front

Plane Mirror Noun

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[pleyn mir-er]

Back

Plane Mirror

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A flat, smooth surface from which light is reflected by specular reflection to form a clear image.

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Example: This diagram shows how a light ray (incident ray) bounces off a plane mirror, creating a reflected ray at an equal angle.

Front

Object Noun

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[ob-jekt]

Back

Object

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A luminous or illuminated source of light rays that can be viewed directly or via reflection or refraction.

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Example: An object is a physical thing that can block the path of light from a light source, causing a shadow to form behind it.

Front

Virtual Image Noun

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[vur-choo-uhl im-ij]

Back

Virtual Image

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An image formed by diverging light rays that appears to be located where the rays do not actually converge.

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Example: Light rays from an object reflect off a plane mirror; your brain sees these rays as coming from a virtual image behind the mirror.

Front

Image Position Noun

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[im-ij puh-zish-un]

Back

Image Position

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The apparent location of an image with respect to a mirror or lens, often denoted as xi.

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Example: This diagram shows light rays from an object reflecting off a flat mirror. The brain perceives a virtual image located behind the mirror.

Front

Front-to-Back Reversal Noun

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[fruhnt-too-bak ri-vur-suhl]

Back

Front-to-Back Reversal

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The effect from a plane mirror where an image is reversed along the axis perpendicular to the mirror's surface.

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Example: This diagram shows that an object in front of a plane mirror forms an image that appears to be behind the mirror, reversing its position from front-to-back.