Related topics: light

NASA's new greenhouse gas detector moves closer to launch

A state-of-the-art imaging spectrometer, which will measure the greenhouse gases methane and carbon dioxide from space, moved closer to launch this month after being delivered to a clean room at Planet Labs PBC (Planet) in ...

Searching for the universe's missing teenage pictures

Astrophysicists can use measurements of the cosmic microwave background, radiation formed 380,000 years after the Big Bang, to understand what the universe was like in its infancy. And by observing light emitted from galaxies ...

A new type of superresolution for exploring cell division

A new way to see details smaller than half the wavelength of light has revealed how nanoscale scaffolding inside cells bridges to the macroscale during cell division. Unlike earlier superresolution techniques, the one developed ...

'Evolving' and 3D printing new nanoscale optical devices

A new technology being pioneered at Caltech is allowing researchers to "evolve" optical devices and then print them out using a specialized type of 3D printer. These devices are made of so-called optical metamaterials that ...

The mutual benefit of agriculture and solar energy

Agricultural photovoltaics (AV) is a concept developed in the 1980s that combines agriculture and solar energy production on the same land. Practitioners grow crops under solar panels and can control the amount and wavelength ...

Identifying organic compounds with visible light

Researchers from the Universidad de Santiago de Chile and the University of Notre Dame, working with machine learning, have devised a method to identify organic compounds based on the refractive index at a single optical ...

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In physics, the wavelength of a sinusoidal wave is the spatial period of the wave – the distance over which the wave's shape repeats. It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a characteristic of both traveling waves and standing waves. Wavelength is commonly designated by the Greek letter lambda (λ). The concept can also be applied to periodic waves of non-sinusoidal shape. The term wavelength is also sometimes applied to modulated waves, and to the sinusoidal envelopes 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 frequency: waves with higher frequencies have shorter wavelengths, and lower frequencies have longer wavelengths.

Examples of wave-like phenomena are sound waves, light, and water waves. A sound wave is a periodic variation in air pressure, while in light and other electromagnetic radiation the strength of the electric and the magnetic field vary. Water waves are periodic variations in the height of a body of water. In a crystal lattice vibration, atomic positions vary periodically in both lattice position and time.

Wavelength is a measure of the distance between repetitions of a shape feature such as peaks, valleys, or zero-crossings, not a measure of how far any given particle moves. For example, in waves over deep water a particle in the water moves in a circle of the same diameter as the wave height, unrelated to wavelength.

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