Wave

Surface waves in water showing water ripples
Example of biological waves expanding over the brain cortex, an example of spreading depolarizations.
Wavelength λ, can be measured between any two corresponding points on a waveform
Animation of two waves, the green wave moves to the right while blue wave moves to the left, the net red wave amplitude at each point is the sum of the amplitudes of the individual waves. Note that f(x,t) + g(x,t) = u(x,t)
Sine, square, triangle and sawtooth waveforms.
Amplitude modulation can be achieved through f(x,t) = 1.00×sin(2π/0.10×(x−1.00×t)) and g(x,t) = 1.00×sin(2π/0.11×(x−1.00×t))only the resultant is visible to improve clarity of waveform.
Illustration of the envelope (the slowly varying red curve) of an amplitude-modulated wave. The fast varying blue curve is the carrier wave, which is being modulated.
The red square moves with the phase velocity, while the green circles propagate with the group velocity
A wave with the group and phase velocities going in different directions
Standing wave. The red dots represent the wave nodes
Light beam exhibiting reflection, refraction, transmission and dispersion when encountering a prism
Sinusoidal traveling plane wave entering a region of lower wave velocity at an angle, illustrating the decrease in wavelength and change of direction (refraction) that results.
Identical waves from two sources undergoing interference. Observed at the bottom one sees 5 positions where the waves add in phase, but in between which they are out of phase and cancel.
Schematic of light being dispersed by a prism. Click to see animation.
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Formation of a shock wave by a plane.
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A propagating wave packet; in general, the envelope of the wave packet moves at a different speed than the constituent waves.
Animation showing the effect of a cross-polarized gravitational wave on a ring of test particles
One-dimensional standing waves; the fundamental mode and the first 5 overtones.
A two-dimensional standing wave on a disk; this is the fundamental mode.
A standing wave on a disk with two nodal lines crossing at the center; this is an overtone.

Propagating dynamic disturbance of one or more quantities.

- Wave
Surface waves in water showing water ripples

46 related topics

Alpha

The propagation of SV-wave in a homogeneous half-space (The horizontal displacement field)

Wave propagation

The propagation of SV-wave in a homogeneous half-space (The horizontal displacement field)
The propagation of SV-wave in a homogeneous half-space (The vertical displacement field)
Seismic wave propagation in 2D modelled using FDTD method in the presence of a landmine

Wave propagation is any of the ways in which waves travel.

James Clerk Maxwell

James Clerk Maxwell

Scottish mathematician and scientist responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism and light as different manifestations of the same phenomenon.

Scottish mathematician and scientist responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism and light as different manifestations of the same phenomenon.

James Clerk Maxwell
Clerk Maxwell's birthplace at 14 India Street in Edinburgh is now the home of the James Clerk Maxwell Foundation.
Edinburgh Academy, where Maxwell was educated
Old College, University of Edinburgh
A young Maxwell at Trinity College, Cambridge, holding one of his colour wheels.
Maxwell proved that the Rings of Saturn were made of numerous small particles.
James Clark Maxwell and his wife by Jemima Blackburn.
Commemoration of Maxwell's equations at King's College. One of three identical IEEE Milestone Plaques, the others being at Maxwell's birthplace in Edinburgh and the family home at Glenlair.
Blue plaque, 16 Palace Gardens Terrace, Kensington, Maxwell's home, 1860–1865
The gravestone at Parton Kirk (Galloway) of James Clerk Maxwell, his parents and his wife
This memorial stone to James Clerk Maxwell stands on a green in front of the church, beside the war memorial at Parton (Galloway).
James Clark Maxwell by Jemima Blackburn.
A postcard from Maxwell to Peter Tait
First durable colour photographic image, demonstrated by Maxwell in an 1861 lecture
Maxwell's demon, a thought experiment where entropy decreases
The James Clerk Maxwell Monument in Edinburgh, by Alexander Stoddart. Commissioned by The Royal Society of Edinburgh; unveiled in 2008.

With the publication of "A Dynamical Theory of the Electromagnetic Field" in 1865, Maxwell demonstrated that electric and magnetic fields travel through space as waves moving at the speed of light.

Frequency dispersion in groups of gravity waves on the surface of deep water. The red square moves with the phase velocity, and the    green circles propagate with the group velocity. In this deep-water case, the phase velocity is twice the group velocity. The red square overtakes two green circles when moving from the left to the right of the figure.
New waves seem to emerge at the back of a wave group, grow in amplitude until they are at the center of the group, and vanish at the wave group front.
For surface gravity waves, the water particle velocities are much smaller than the phase velocity, in most cases.

Group velocity

Frequency dispersion in groups of gravity waves on the surface of deep water. The red square moves with the phase velocity, and the    green circles propagate with the group velocity. In this deep-water case, the phase velocity is twice the group velocity. The red square overtakes two green circles when moving from the left to the right of the figure.
New waves seem to emerge at the back of a wave group, grow in amplitude until they are at the center of the group, and vanish at the wave group front.
For surface gravity waves, the water particle velocities are much smaller than the phase velocity, in most cases.
Propagation of a wave packet demonstrating a phase velocity greater than the group velocity without dispersion.
This shows a wave with the group velocity and phase velocity going in different directions. The group velocity is positive (i.e., the envelope of the wave moves rightward), while the phase velocity is negative (i.e., the peaks and troughs move leftward).

The group velocity of a wave is the velocity with which the overall envelope shape of the wave's amplitudes—known as the modulation or envelope of the wave—propagates through space.

A pseudocolor image of two people taken in long-wavelength infrared (body-temperature thermal) radiation.

Infrared

Electromagnetic radiation (EMR) with wavelengths longer than those of visible light.

Electromagnetic radiation (EMR) with wavelengths longer than those of visible light.

A pseudocolor image of two people taken in long-wavelength infrared (body-temperature thermal) radiation.
This false-color infrared space telescope image has blue, green and red corresponding to 3.4, 4.6, and 12 μm wavelengths, respectively.
Plot of atmospheric transmittance in part of the infrared region
Materials with higher emissivity appear closer to their true temperature than materials that reflect more of their different-temperature surroundings. In this thermal image, the more reflective ceramic cylinder, reflecting the cooler surroundings, appears to be colder than its cubic container (made of more emissive silicon carbide), while in fact, they have the same temperature.
Active-infrared night vision: the camera illuminates the scene at infrared wavelengths invisible to the human eye. Despite a dark back-lit scene, active-infrared night vision delivers identifying details, as seen on the display monitor.
Thermography helped to determine the temperature profile of the Space Shuttle thermal protection system during re-entry.
Hyperspectral thermal infrared emission measurement, an outdoor scan in winter conditions, ambient temperature −15 °C, image produced with a Specim LWIR hyperspectral imager. Relative radiance spectra from various targets in the image are shown with arrows. The infrared spectra of the different objects such as the watch clasp have clearly distinctive characteristics. The contrast level indicates the temperature of the object.
Infrared light from the LED of a remote control as recorded by a digital camera
Reflected light photograph in various infrared spectra to illustrate the appearance as the wavelength of light changes.
Infrared hair dryer for hair salons, c. 2010s
IR satellite picture of cumulonimbus clouds over the Great Plains of the United States.
The greenhouse effect with molecules of methane, water, and carbon dioxide re-radiating solar heat
Beta Pictoris with its planet Beta Pictoris b, the light-blue dot off-center, as seen in infrared. It combines two images, the inner disc is at 3.6 μm.
An infrared reflectogram of Mona Lisa by Leonardo da Vinci
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Thermographic image of a snake eating a mouse
Infrared radiation was discovered in 1800 by William Herschel.

As a form of electromagnetic radiation, IR propagates energy and momentum, with properties corresponding to both those of a wave and of a particle, the photon.

Various examples of physical phenomena

Physics

Natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force.

Natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force.

Various examples of physical phenomena
Ancient Egyptian astronomy is evident in monuments like the ceiling of Senemut's tomb from the Eighteenth Dynasty of Egypt.
Ibn al-Haytham (c. 965–c. 1040), Book of Optics Book I, [6.85], [6.86]. Book II, [3.80] describes his camera obscura experiments.
The basic way a pinhole camera works
Galileo Galilei showed a modern appreciation for the proper relationship between mathematics, theoretical physics, and experimental physics.
Sir Isaac Newton (1643–1727), whose laws of motion and universal gravitation were major milestones in classical physics
Max Planck (1858–1947), the originator of the theory of quantum mechanics
Albert Einstein (1879–1955), whose work on the photoelectric effect and the theory of relativity led to a revolution in 20th century physics
The basic domains of physics
Solvay Conference of 1927, with prominent physicists such as Albert Einstein, Werner Heisenberg, Max Planck, Hendrik Lorentz, Niels Bohr, Marie Curie, Erwin Schrödinger and Paul Dirac
This parabola-shaped lava flow illustrates the application of mathematics in physics—in this case, Galileo's law of falling bodies.
Mathematics and ontology are used in physics. Physics is used in chemistry and cosmology.
The distinction between mathematics and physics is clear-cut, but not always obvious, especially in mathematical physics.
Classical physics implemented in an acoustic engineering model of sound reflecting from an acoustic diffuser
Archimedes' screw, a simple machine for lifting
Experiment using a laser
The astronaut and Earth are both in free fall.
Lightning is an electric current.
Physics involves modeling the natural world with theory, usually quantitative. Here, the path of a particle is modeled with the mathematics of calculus to explain its behavior: the purview of the branch of physics known as mechanics.
A simulated event in the CMS detector of the Large Hadron Collider, featuring a possible appearance of the Higgs boson.
Velocity-distribution data of a gas of rubidium atoms, confirming the discovery of a new phase of matter, the Bose–Einstein condensate
The deepest visible-light image of the universe, the Hubble Ultra-Deep Field
Feynman diagram signed by R. P. Feynman.
A typical phenomenon described by physics: a magnet levitating above a superconductor demonstrates the Meissner effect.

Wave

The 2004 Indian Ocean tsunami at Ao Nang, Krabi Province, Thailand

Tsunami

Series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake.

Series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake.

The 2004 Indian Ocean tsunami at Ao Nang, Krabi Province, Thailand
Tsunami aftermath in Aceh, Indonesia, December 2004.
Lisbon earthquake and tsunami in November 1755.
When the wave enters shallow water, it slows down and its amplitude (height) increases.
The wave further slows and amplifies as it hits land. Only the largest waves crest.
An illustration of the rhythmic "drawback" of surface water associated with a wave. It follows that a very large drawback may herald the arrival of a very large wave.
Diagram showing several measures to describe a tsunami size, including height, inundation and run-up.
Calculated travel time map for the 1964 Alaska tsunami (in hours)
One of the deep water buoys used in the DART tsunami warning system
A seawall at Tsu, Mie Prefecture in Japan
Drawing of tectonic plate boundary before earthquake
Over-riding plate bulges under strain, causing tectonic uplift.
Plate slips, causing subsidence and releasing energy into water.
The energy released produces tsunami waves.
Tsunami hazard sign at Bamfield, British Columbia
A tsunami warning sign in Kamakura, Japan
A Tsunami hazard sign (Spanish - English) in Iquique, Chile.
alt=Photo of evacuation sign|Tsunami Evacuation Route signage along U.S. Route 101, in Washington

All waves have a positive and negative peak; that is, a ridge and a trough.

Increase of amplitude as damping decreases and frequency approaches resonant frequency of a driven damped simple harmonic oscillator.

Resonance

Applied periodic force is equal or close to a natural frequency of the system on which it acts.

Applied periodic force is equal or close to a natural frequency of the system on which it acts.

Increase of amplitude as damping decreases and frequency approaches resonant frequency of a driven damped simple harmonic oscillator.
Pushing a person in a swing is a common example of resonance. The loaded swing, a pendulum, has a natural frequency of oscillation, its resonant frequency, and resists being pushed at a faster or slower rate.
An RLC series circuit
A mass on a spring has one natural frequency, as it has a single degree of freedom
A standing wave (in black), created when two waves moving from left and right meet and superimpose
Standing waves in a string – the fundamental mode and the first 5 harmonics.
School resonating mass experiment
Animation illustrating electrical resonance in a tuned circuit, consisting of a capacitor (C) and an inductor (L) connected together. Charge flows back and forth between the capacitor plates through the inductor. Energy oscillates back and forth between the capacitor's electric field (E) and the inductor's magnetic field (B).
NMR Magnet at HWB-NMR, Birmingham, UK. In its strong 21.2-tesla field, the proton resonance is at 900 MHz.
High and low Q factor
"Universal Resonance Curve", a symmetric approximation to the normalized response of a resonant circuit; abscissa values are deviation from center frequency, in units of center frequency divided by 2Q; ordinate is relative amplitude, and phase in cycles; dashed curves compare the range of responses of real two-pole circuits for a Q value of 5; for higher Q values, there is less deviation from the universal curve. Crosses mark the edges of the 3 dB bandwidth (gain 0.707, phase shift 45° or 0.125 cycle).

Resonance phenomena occur with all types of vibrations or waves: there is mechanical resonance, acoustic resonance, electromagnetic resonance, nuclear magnetic resonance (NMR), electron spin resonance (ESR) and resonance of quantum wave functions.

Illustration of a simple (plane) transverse wave propagating through an elastic medium in the horizontal direction, with particles being displaced in the vertical direction. Only one layer of the material is shown

Transverse wave

Illustration of a simple (plane) transverse wave propagating through an elastic medium in the horizontal direction, with particles being displaced in the vertical direction. Only one layer of the material is shown
Illustration of the electric (red) and magnetic (blue) fields along a ray in a simple light wave. For any plane perpendicular to the ray, each field has always the same value at all points of the plane.
Propagation of a transverse spherical wave in a 2d grid (empirical model)
Circular polarization mechanically generated on a rubber thread, converted to linear polarization by a mechanical polarizing filter.

In physics, a transverse wave is a wave whose oscillations are perpendicular to the direction of the wave's advance.

Crest and trough in a wave

Crest and trough

Crest and trough in a wave

A crest point on a wave is the maximum value of upward displacement within a cycle.

Wavelength of a sine wave, λ, can be measured between any two consecutive points with the same phase, such as between adjacent crests, or troughs, or adjacent zero crossings with the same direction of transit, as shown.

Wave vector

Wavelength of a sine wave, λ, can be measured between any two consecutive points with the same phase, such as between adjacent crests, or troughs, or adjacent zero crossings with the same direction of transit, as shown.

In physics, a wave vector (also spelled wavevector) is a vector which helps describe a wave.