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Wavelength is the distance between the crests of a wave, such as an electromagnetic wave or an ocean wave. It is given in units of length and is the reciprocal of frequency.

Wavelength is a key concept in wave physics, describing the distance between successive peaks (or troughs) of a wave. It is a crucial parameter in understanding various types of waves, including electromagnetic waves, sound waves, and water waves.

• Definition: Wavelength (\( \lambda \)) is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is usually measured from peak to peak or trough to trough.
• Units of Measurement: Wavelength is commonly expressed in meters (m), centimeters (cm), millimeters (mm), or nanometers (nm), depending on the type of wave. For example, visible light has wavelengths ranging from about 400 nm to 700 nm, while radio waves can have wavelengths ranging from millimeters to kilometers.

• Inverse Relationship: Wavelength and frequency (\( \nu \)) are inversely related through the equation \( \text{c} = \lambda \times \nu \), where \( \text{c} \) is the speed of light in a vacuum (approximately \( 3 \times 10^8 \) meters per second). As the frequency increases, the wavelength decreases, and vice versa.
• Practical Implications: This relationship means that waves with higher frequencies, such as X-rays or gamma rays, have shorter wavelengths, whereas waves with lower frequencies, like radio waves, have longer wavelengths.

• Electromagnetic Spectrum: Wavelength plays a crucial role in the electromagnetic spectrum. Different regions of the spectrum, such as ultraviolet, visible, and infrared, are characterized by their respective wavelength ranges. Each region has distinct properties and uses.
• Communication Technologies: In telecommunications, different wavelength ranges are used for various technologies. For instance, fiber optics use wavelengths in the near-infrared range (around 1300 nm and 1550 nm) to transmit data over long distances with minimal loss.

• Spectroscopy: Spectroscopy involves measuring the wavelengths of light emitted or absorbed by materials. Instruments like spectrometers and monochromators are used to analyze these wavelengths and gain information about the material's properties.
• Wavelength Meters: Wavelength meters are specialized devices used to measure the wavelength of light with high precision. They are essential in various scientific and industrial applications, including laser calibration and optical testing.

• https://en.wikipedia.org/wiki/Wavelength
• https://www.britannica.com/science/wavelength
• https://www.sciencedirect.com/topics/earth-and-planetary-sciences/wavelength

Snippet from Wikipedia: Wavelength

In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, troughs, or zero crossings. Wavelength is a characteristic of both traveling waves and standing waves, as well as other spatial wave patterns. The inverse of the wavelength is called the spatial frequency. Wavelength is commonly designated by the Greek letter lambda (λ). For a modulated wave, wavelength may refer to the carrier wavelength of the signal. The term wavelength may also apply to the repeating envelope of modulated waves or waves formed by interference of several sinusoids.

Assuming a sinusoidal wave moving at a fixed wave speed, wavelength is inversely proportional to the frequency of the wave: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.

Wavelength depends on the medium (for example, vacuum, air, or water) that a wave travels through. Examples of waves are sound waves, light, water waves and periodic electrical signals in a conductor. A sound wave is a variation in air pressure, while in light and other electromagnetic radiation the strength of the electric and the magnetic field vary. Water waves are variations in the height of a body of water. In a crystal lattice vibration, atomic positions vary.

The range of wavelengths or frequencies for wave phenomena is called a spectrum. The name originated with the visible light spectrum but now can be applied to the entire electromagnetic spectrum as well as to a sound spectrum or vibration spectrum.

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