Near-infrared light, whose wavelength is longer than visible light, is invisible and can pass through many substances. Organic materials that efficiently absorb near-infrared light are essential for technological innovations ...
Analytical Chemistry
39 minutes ago
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When matter falls into supermassive black holes in the centers of galaxies, it unleashes enormous amounts of energy and is called an active galactic nuclei (or AGN). A fraction of AGN release part of this energy as jets that ...
Astronomy
Mar 21, 2023
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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 ...
A large international team of space scientists has discovered that the detection of an exoplanet orbiting the star 40 Eridani was made in error. The group has published a paper on the arXiv pre-print server describing their ...
In places across the U.S., tree cover is shrinking—forests are burned by wildfires on the West Coast and drowned by rising sea levels along the East. From the ground, it's hard to assess the scale of the losses and the ...
Planetary Sciences
Mar 8, 2023
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A new purpose-built microscope has been developed that uses the complex properties of UV light to improve image resolution and contrast. Most cells are transparent at visible wavelengths, which means the imaginary component ...
Optics & Photonics
Mar 6, 2023
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A "jellyfish galaxy" with trailing tentacles of stars hangs in inky blackness in this image from the NASA/ESA Hubble Space Telescope. As jellyfish galaxies move through intergalactic space, gas is slowly stripped away forming ...
Astronomy
Mar 6, 2023
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Visible light is just one part of the electromagnetic spectrum that astronomers use to study the universe. The James Webb Space Telescope was built to see infrared light, other space telescopes capture X-ray images, and observatories ...
Astronomy
Mar 3, 2023
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When scientists develop new optical techniques and instruments for medical diagnosis, surgery, or light-based therapy, those techniques and instruments must be validated and calibrated through extensive testing. The test ...
Optics & Photonics
Feb 21, 2023
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For the first time, an international team of researchers, including those from the University of Tokyo's Institute for Solid State Physics, has demonstrated a switch, analogous to a transistor, made from a single molecule ...
Condensed Matter
Feb 21, 2023
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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.
This text uses material from Wikipedia, licensed under CC BY-SA
