Properties of Light

Front

Electromagnetic Radiation Noun

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[eh-lek-tro-mag-net-ik ray-dee-ay-shun]

Back

Electromagnetic Radiation

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A form of energy, such as light, that exhibits wave-like behavior as it travels through space.

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Example: This diagram shows the electromagnetic spectrum, a range of energy waves with different wavelengths, from gamma rays to radio waves, including visible light.

Front

Crest Noun

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[krest]

Back

Crest

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The highest point or peak of a transverse wave, representing the maximum upward displacement from the rest position.

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Example: This diagram of a transverse wave, the model for light, clearly labels the 'Crest' as the highest point the wave reaches from its equilibrium position.

Front

Trough Noun

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[trof]

Back

Trough

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The lowest point or valley of a transverse wave, representing the maximum downward displacement from the rest position.

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Example: This diagram shows a wave, like a light wave. The trough is the lowest point of the wave, the opposite of the highest point, called the crest.

Front

Rest Position Noun

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[rest puh-zish-un]

Back

Rest Position

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The equilibrium or undisturbed position of the particles in a medium when no wave is passing through it.

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Example: This diagram shows a wave, like a light wave, and points to the 'rest position,' which is the straight line representing the wave's equilibrium or zero-energy level.

Front

Transverse Wave Noun

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[trans-vurs wayv]

Back

Transverse Wave

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A wave in which the particles of the medium move in a direction perpendicular to the direction of wave travel.

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Example: This diagram shows a transverse wave, illustrating its key parts: the highest point (peak), lowest point (trough), height from the center (amplitude), and length of one wave cycle (wavelength).

Front

Longitudinal Wave Noun

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[lon-ji-too-din-ul wayv]

Back

Longitudinal Wave

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A wave in which the particles of the medium move in a direction parallel to the direction of wave travel.

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Example: This image shows a longitudinal wave using a spring; the wave's energy moves in the same direction as the spring's back-and-forth motion, creating compressions.

Front

Wavelength (λ) Noun

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[wayv-length]

Back

Wavelength (λ)

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The length of one complete wave cycle, measured as the distance between two consecutive identical points on a wave.

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Example: This diagram shows a wave and labels the wavelength as the distance between two identical points, in this case, from the bottom of one trough to the next.

Front

Amplitude Noun

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[am-pli-tood]

Back

Amplitude

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The maximum displacement or distance a wave vibrates from its rest position, which is related to the wave's energy.

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Example: This diagram shows a wave and uses a vertical arrow to indicate the amplitude, which is the maximum height of the wave from its center line.

Front

Period (T) Noun

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[peer-ee-ud]

Back

Period (T)

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The time required for one complete cycle or wavelength to pass a specific point in space.

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Example: This graph shows a wave's motion over time. The period (T) is the time it takes to complete one full cycle, like from one peak to the next.

Front

Frequency (f) Noun

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[free-kwen-see]

Back

Frequency (f)

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The number of complete wavelengths that pass a specific point in a given amount of time.

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Example: This graph shows a light wave with a low frequency, meaning few wave crests pass a point over a period of time (t).