Lasers used for visual effects during a musical performance.
Primary (42*) and secondary rainbows(51*) are visible, as well as a reflected primary and a faintly visible reflection primary. The secondary rainbow is higher than the primary and has inverted colors. (from hyperphysics.phyastr.gsu.edu).
Xrays can reveal the details of bones and teeth The electromagnetic wave equation is a secondorder partial differential equation that describes the propagation of electromagnetic waves through a medium or in a vacuum. The homogeneous form of the equation, written in terms of either the electric field E or the magnetic field H, takes the form: Image File history File links Download high resolution version (1600x1067, 348 KB) Classical Specatular featured state of the art laser and lighting designed by Durham Marenghi Photo taken at ISO 1600 with no tripod File links The following pages link to this file: Laser Lighting ...
Image File history File links Download high resolution version (1600x1067, 348 KB) Classical Specatular featured state of the art laser and lighting designed by Durham Marenghi Photo taken at ISO 1600 with no tripod File links The following pages link to this file: Laser Lighting ...
Download high resolution version (1784x1188, 1089 KB)Public domain. ...
Download high resolution version (1784x1188, 1089 KB)Public domain. ...
A combined microwave and fanassisted oven. ...
A combined microwave and fanassisted oven. ...
Photo by dene. From http://www. ...
Photo by dene. From http://www. ...
In the NATO phonetic alphabet, Xray represents the letter X. An Xray picture (radiograph) taken by Röntgen An Xray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz...
Download high resolution version (546x697, 80 KB)The only information given by the source about this image is Radar. We can deduce a few more things from this image: The dish rotates on a circular track The facility is in the tropics (because of palm trees) The dish is approximately...
Download high resolution version (546x697, 80 KB)The only information given by the source about this image is Radar. We can deduce a few more things from this image: The dish rotates on a circular track The facility is in the tropics (because of palm trees) The dish is approximately...
A yagi antenna Most simply, an antenna is an electronic component designed to send or receive radio waves. ...
An antiballistic missile (ABM) is a missile designed to counter ballistic missiles. ...
Kwajalein infrastructure and RTS headquarters, click to enlarge. ...
Kwajalein Atoll  NASA NLT Landsat 7 (Visible Color) Satellite Image Kwajalein Atoll (Marshallese: Kuwajleen) is part of the Republic of the Marshall Islands (RMI). ...
An atoll is a type of low, coral island found in tropical oceans and consisting of a coralalgal reef surrounding a central depression. ...
Image File history File linksMetadata Download high resolution version (1579x1335, 525 KB) Summary Fiber optic strands. ...
Image File history File linksMetadata Download high resolution version (1579x1335, 525 KB) Summary Fiber optic strands. ...
In mathematics, a partial differential equation (PDE) is a relation involving an unknown function of several independent variables and its partial derivatives with respect to those variables. ...
Free space is the most simple and elementary electromagnetic medium. ...
Look up Vacuum in Wiktionary, the free dictionary. ...
In mathematics, homogeneous may refer to: a homogeneous polynomial, in algebra a homogeneous function a homogeneous differential equation a homogeneous system of linear equations, in linear algebra homogeneous coordinates a homogeneous number a homogeneous space for a Lie group G, or more general transformation group a homogeneous ideal in a...
In physics, an electric field or Efield is an effect produced by an electric charge (or a timevarying magnetic field) that exerts a force on charged objects in the field. ...
To meet Wikipedias quality standards, this article may require cleanup. ...
where c is the speed of light in the medium. In a vacuum, c = 2.998 x 10^{8} meters per second, which is the speed of light in free space. The speed of light in a vacuum is an important physical constant denoted by the letter c for constant or the Latin word celeritas meaning swiftness. In metric units, c is exactly 299,792,458 metres per second (1,079,252,848. ...
In physics, free space is a concept of electromagnetic theory, corresponding roughly to the vacuum, the baseline state of the electromagnetic field, or the replacement for the electromagnetic aether. ...
The electromagnetic wave equation derives from Maxwell's equations. Maxwells equations (sometimes called the Maxwell equations) are the set of four equations, attributed to James Clerk Maxwell, that describe the behavior of both the electric and magnetic fields, as well as their interactions with matter. ...
In a linear, isotropic, nondispersive medium, the magnetic flux density B is related to the magnetic field H by Current flowing through a wire produces a magnetic field (B, labeled M here) around the wire. ...
where μ is the magnetic permeability of the medium. In electromagnetism, permeability is the degree of magnetisation of a material that responds linearly to an applied magnetic field. ...
It should also be noted that in most modern literature, B is called the "magnetic field," and H is called either the "auxiliary magnetic field," or "the H vector." In this article, it is most appropriate to use SI units through the motivation and derivation of the homogeneous wave equation. Once the marriage between electromagnetism and light has been made, and the relationship between the permitivity/permeability and the speed of light has been derived, it is often useful to use other units, such as cgs or LorentzHeaviside. At that point, we display results in all three sets of units. Cover of brochure The International System of Units. ...
This article or section is in need of attention from an expert on the subject. ...
LorentzHeaviside units for Maxwells equations are often used in relativistic calculations. ...
Speed of propagation
In vacuum If the wave propagation is in vacuum, then  meters per second
is the speed of light in free space. The magnetic permeability and the electric permittivity are important physical constants that play a key role in electromagnetic theory. The speed of light in a vacuum is an important physical constant denoted by the letter c for constant or the Latin word celeritas meaning swiftness. In metric units, c is exactly 299,792,458 metres per second (1,079,252,848. ...
In physics, free space is a concept of electromagnetic theory, corresponding roughly to the vacuum, the baseline state of the electromagnetic field, or the replacement for the electromagnetic aether. ...
In electromagnetism, permeability is the degree of magnetisation of a material that responds linearly to an applied magnetic field. ...
Permittivity is a physical quantity that describes how an electric field affects and is affected by a dielectric medium and is determined by the ability of a material to polarize in response to an applied electric field, and thereby to cancel, partially, the field inside the material. ...
In science, a physical constant is a physical quantity whose numerical value does not change. ...
Electromagnetism is the force observed as static electricity, and causes the flow of electric charge (electric current) in electrical conductors. ...
Symbol  Name  Numerical Value  SI Unit of Measure  Type   Speed of light   meters per second  defined   Permittivity   farads per meter  derived   Permeability   henries per meter  defined  The farad (symbol F) is the SI unit of capacitance (named after Michael Faraday). ...
An inductor. ...
In a material medium For the purposes of this article, we will assume that all materials are linear, isotropic, and nondispersive. In that case, the speed of light in a material medium is where is the refractive index of the medium, is the magnetic permeability of the medium, and is the electric permittivity of the medium. The refractive index (or index of refraction) of a material is the factor by which the phase velocity of electromagnetic radiation is slowed in that material, relative to its velocity in a vacuum. ...
The origin of the electromagnetic wave equation Conservation of charge Conservation of charge requires that the time rate of change of the total charge enclosed within a volume V must equal the net current flowing into the surface S enclosing the volume: Charge conservation is the principle that electric charge can neither be created nor destroyed. ...
where J is the current density (in amperes per square meter) flowing through the surface and ρ is the charge density (in coulombs per cubic meter) at each point in the volume. In physics, the ampere (symbol: A, often informally abbreviated to amp) is the SI base unit used to measure electrical currents. ...
The coulomb (symbol: C) is the SI unit of electric charge. ...
From the divergence theorem, we can convert this relationship from integral form to differential form: In vector calculus, the divergence theorem, also known as Gauss theorem, Ostrogradskys theorem, or Ostrogradskyâ€“Gauss theorem is a result that links the divergence of a vector field to the value of surface integrals of the flow defined by the field. ...
Ampere's Law prior to Maxwell's correction In its original form, Ampere's Law (SI units) relates the magnetic field H to its source, the current density J: Image File history File links Ampere1. ...
January 20 is the 20th day of the year in the Gregorian calendar. ...
1775 was a common year starting on Sunday (see link for calendar). ...
June 10 is the 161st day of the year in the Gregorian calendar (162nd in leap years), with 204 days remaining. ...
October 2, Charles Darwin returns from his voyage around the world. ...
City flag Coat of arms Motto: By her great deeds, Marseille shines in the world Coordinates Time Zone CET (GMT +1) Administration Country France RÃ©gion ProvenceAlpesCÃ´te dAzur DÃ©partement BouchesduRhÃ´ne (13) Subdivisions 16 arrondissements (in 8 secteurs) Intercommunality Urban Community of Marseille...
Physicists working in a government lab A physicist is a scientist who studies or practices physics. ...
In physics, Ampères law is the magnetic equivalent of Gausss law, discovered by AndréMarie Ampère. ...
Again, we can convert to differential form, this time using Stokes' theorem: Stokess theorem in differential geometry is a statement about the integration of differential forms which generalizes several theorems from vector calculus. ...
Inconsistency between Ampere's Law and Conservation of Charge James Clerk Maxwell, who unified the laws of electricity and magnetism, discovered an important inconsistency between Ampere's Law and the Conservation of Charge. James Clerk Maxwell (13 June 1831 â€“ 5 November 1879) was a Scottish mathematical physicist, born in Edinburgh. ...
If we take the divergence of both sides of Ampere's Law, we find The divergence of the curl of any vector field – in this case, the magnetic field H – is always equal to zero:
A multiband rotary directional antenna for Amateur Radio use Combining these two equations implies that Image File history File linksMetadata Antenna_d44ac. ...
Image File history File linksMetadata Antenna_d44ac. ...
From the conservation of charge, we know that This last result suggests that the net charge density at any point in space is a fixed constant that cannot ever change, which is of course absurd. Not only is this outcome contrary to all physical intuition, it also directly contradicts the empirical results of thousands of laboratory experiments. It requires not only that electrical charge is conserved, but that it cannot be redistributed from one place to another. But we know that electrical currents can and do redistribute electrical charge. As long as the total amount of charge remains constant, conservation of charge allows for the movement of charge from one place to another. So this last result is incorrect. Something was clearly missing from Ampere's Law, and Maxwell figured out what it was.
Maxwell's correction to Ampere's Law To understand Maxwell's correction to Ampere's Law, we need to look at another of Maxwell's Equations, namely, Gauss's Law (SI units) in integral form: In physics and mathematical analysis, Gausss law gives the relation between the electric or gravitational flux flowing out a closed surface and, respectively, the electric charge or mass enclosed in the surface. ...
Again, using the divergence theorem, we can convert this equation to differential form: Taking the derivative with respect to time of both sides, we find: Reversing the order of differentiation on the lefthand side, we obtain This last result, along with Ampere's Law and the conservation of charge equation, suggests that there are actually two sources of the magnetic field: the current density J, as Ampere had already established, and the socalled displacement current: Displacement current is a quantity related to a changing electric field. ...
So the corrected form of Ampere's Law, which Maxwell discovered, becomes: Maxwell  First to propose that light is an electromagnetic wave
Father of Electromagnetic Theory Maxwell's correction of Ampere's Law set the stage for an even more important and, at the time, startling discovery made by Heinrich Rudolph Hertz. Maxwell realized that the equations of electromagnetism suggest that electric and magnetic fields can propagate through free space – in other words, in the absence of matter – as electromagnetic waves, and further, that the speed of propagation of these waves is exactly the same as the speed of light. Reflecting on his discovery in 1865, Maxwell wrote: Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...
Postcard from James Clerk Maxwell to Peter Guthrie Tait. ...
Postcard from James Clerk Maxwell to Peter Guthrie Tait. ...
Peter Tait Peter Guthrie Tait (April 28, 1831  July 4, 1901) was a Scottish mathematical physicist. ...
Heinrich Hertz Heinrich Rudolf Hertz (February 22, 1857  January 1, 1894), was the German physicist for whom the hertz, the SI unit of frequency, is named. ...
The speed of light in a vacuum is an important physical constant denoted by the letter c for constant or the Latin word celeritas meaning swiftness. In metric units, c is exactly 299,792,458 metres per second (1,079,252,848. ...
1865 (MDCCCLXV) is a common year starting on Sunday. ...
 This velocity is so nearly that of light, that it seems we have strong reason to conclude that light itself . . . is an electromagnetic disturbance in the form of waves propagated through the electromagnetic field according to electromagnetic laws.
To obtain electromagnetic waves in a vacuum note that Maxwell's equations (SI units) in a vacuum are Electromagnetic radiation or EM radiation is a combination (cross product) of oscillating electric and magnetic fields perpendicular to each other, moving through space as a wave, effectively transporting energy and momentum. ...
If we take the curl of the curl equations we obtain If we note the vector identity where is any vector function of space, we recover the wave equations where  meters per second
is the speed of light in free space.
Covariant form of the homogeneous wave equation
Time dilation in transversal motion. The requirement that the speed of light is constant in every inertial reference frame leads to the theory of relativity These relativistic equations can be written in covariant form as Image File history File links This animated GIF is meant to be used as an illustration for the time dilation article. ...
The special theory of relativity was proposed in 1905 by Albert Einstein in his article On the Electrodynamics of Moving Bodies. Some three centuries earlier, Galileos principle of relativity had stated that all uniform motion was relative, and that there was no absolute and welldefined state of rest...
In special relativity, in order to more clearly express the fact that Maxwells equations (in vacuum) take the same form in any inertial coordinate system, the vacuum Maxwells equations are written in terms of fourvectors and tensors in the manifestly covariant form (cgs units): , and where is...
It has been suggested that this article or section be merged into Covariant transformation. ...
where the electromagnetic fourpotential is Electromagnetic potential is . ...


with the Lorenz gauge  .
Here  is the d'Alembertian operator. The square box is not a typographical error; it is the correct symbol for this operator.
In special relativity, electromagnetism and wave theory, the dAlembert operator, also called dAlembertian, is the Laplace operator of Minkowski space. ...
Homogeneous wave equation in curved spacetime 
The electromagnetic wave equation is modified in two ways, the derivative is replaced with the covariant derivative and a new term that depends on the curvature appears. To meet Wikipedias quality standards, this article or section may require cleanup. ...
In mathematics, the covariant derivative is a way of specifying a derivative along vector fields on a manifold. ...
where is the Ricci curvature tensor and the semicolon indicates covariant differentiation. In differential geometry, the Ricci curvature tensor is (0,2)valent tensor, obtained as a trace of the full curvature tensor. ...
We have assumed the generalization of the Lorenz gauge in curved spacetime The Lorenz gauge (or Lorenz gauge condition) was published by the Danish physicist Ludwig Lorenz. ...
 .
Inhomogeneous electromagnetic wave equation 
Localized timevarying charge and current densities can act as sources of electromagnetic waves in a vacuum. Maxwell's equations can be written in the form of a wave equation with sources. The addition of sources to the wave equations makes the partial differential equations inhomogeneous. Localized timevarying charge and current densities can act as sources of electromagnetic waves in a vacuum. ...
In mathematics, and in particular analysis, a partial differential equation (PDE) is an equation involving partial derivatives of an unknown function. ...
Solutions to the homogeneous electromagnetic wave equation 
The general solution to the electromagnetic wave equation is a linear superposition of waves of the form The wave equation is an important partial differential equation that describes a variety of waves, such as sound waves, light waves and water waves. ...
In linear algebra, the principle of superposition states that, for a linear system, a linear combination of solutions to the system is also a solution to the same linear system. ...
and for virtually any wellbehaved function g of dimensionless argument φ, where  is the angular frequency (in radians per second), and
 is the wave vector (in radians per meter).
Although the function g can be and often is a monochromatic sine wave, it does not have to be sinusoidal, or even periodic. In practice, g cannot have infinite periodicity because any real electromagnetic wave must always have a finite extent in time and space. As a result, and based on the theory of Fourier decomposition, a real wave must consist of the superposition of an infinite set of sinusoidal frequencies. It has been suggested that this article or section be merged into Angular velocity. ...
A wave vector is a vector that represents two properties of a wave: the magnitude of the vector represents wavenumber (inversely related to wavelength), and the vector points in the direction of wave propagation. ...
In trigonometry, an ideal sine wave is a waveform whose graph is identical to the generalized sine function y = Asin[ω(x − α)] + C, where A is the amplitude, ω is the angular frequency (2π/P where P is the wavelength), α is the phase shift, and C...
In mathematics, the Fourier transform is a certain linear operator that maps functions to other functions. ...
In addition, for a valid solution, the wave vector and the angular frequency are not independent; they must adhere to the dispersion relation: The relation between the energy of a system and its corresponding momentum is known as its dispersion relation. ...
where k is the wavenumber and λ is the wavelength. Wavenumber in most physical sciences is a wave property inversely related to wavelength, having units of inverse length. ...
The wavelength is the distance between repeating units of a wave pattern. ...
Monochromatic, sinusoidal steadystate The simplest set of solutions to the wave equation result from assuming sinusoidal waveforms of a single frequency in separable form: where In mathematics, the imaginary unit (sometimes also represented by the Latin or the Greek iota) allows the real number system to be extended to the complex number system . ...
It has been suggested that this article or section be merged into Angular velocity. ...
Angular frequency is a measure of how fast an object is rotating In physics (specifically mechanics and electrical engineering), angular frequency Ï‰ (also called angular speed) is a scalar measure of rotation rate. ...
Sine waves of various frequencies; the lower waves have higher frequencies than those above. ...
The hertz (symbol: Hz) is the SI unit of frequency. ...
Eulers formula, named after Leonhard Euler, is a mathematical formula in complex analysis that shows a deep relationship between the trigonometric functions and the complex exponential function. ...
Plane wave solutions 
Main article: Sinusoidal planewave solutions of the electromagnetic wave equation Consider a plane defined by a unit normal vector Perhaps the most useful solutions to the electromagnetic wave equation are sinusoidal planewave solutions. ...
 .
Then planar traveling wave solutions of the wave equations are and where  is the position vector (in meters).
These solutions represent planar waves traveling in the direction of the normal vector . If we define the z direction as the direction of and the x direction as the direction of , then by Faraday's Law the magnetic field lies in the y direction and is related to the electric field by the relation  .
Because the divergence of the electric and magnetic fields are zero, there are no fields in the direction of propagation. This solution is the linearly polarized solution of the wave equations. There are also circularly polarized solutions in which the fields rotate about the normal vector. In electrodynamics, polarization (also spelled polarisation) is the property of electromagnetic waves, such as light, that describes the direction of their transverse electric field. ...
Spectral decomposition Because of the linearity of Maxwell's equations in a vacuum, solutions can be decomposed into a superposition of sinusoids. This is the basis for the Fourier transform method for the solution of differential equations. The sinusoidal solution to the electromagnetic wave equation takes the form In mathematics, the trigonometric functions are functions of an angle, important when studying triangles and modeling periodic phenomena. ...
In mathematics, the Fourier transform is a certain linear operator that maps functions to other functions. ...
Electromagnetic spectrum illustration. and Image File history File links Spectre. ...
Image File history File links Spectre. ...
where  is time (in seconds),
 is the angular frequency (in radians per second),
 is the wave vector (in radians per meter), and
 is the phase angle (in radians).
The wave vector is related to the angular frequency by It has been suggested that this article or section be merged into Angular velocity. ...
A wave vector is a vector that represents two properties of a wave: the magnitude of the vector represents wavenumber (inversely related to wavelength), and the vector points in the direction of wave propagation. ...
The phase angle of a point on a periodic wave is the distance between the point and a specified reference point, expressed using an angular measure. ...
where k is the wavenumber and λ is the wavelength. Wavenumber in most physical sciences is a wave property inversely related to wavelength, having units of inverse length. ...
The wavelength is the distance between repeating units of a wave pattern. ...
The Electromagnetic spectrum is a plot of the field magnitudes (or energies) as a function of wavelength. Legend: Î³ = Gamma rays HX = Hard Xrays SX = Soft XRays EUV = Extreme ultraviolet NUV = Near ultraviolet Visible light NIR = Near infrared MIR = Moderate infrared FIR = Far infrared Radio waves: EHF = Extremely high frequency (Microwaves) SHF = Super high frequency (Microwaves) UHF = Ultra high frequency VHF = Very high frequency HF = High...
Other solutions Spherically symmetric and cylindrically symmetric analytic solutions to the electromagnetic wave equations are also possible.
References Electromagnetics Journal articles  James Clerk Maxwell, "A Dynamical Theory of the Electromagnetic Field", Philosophical Transactions of the Royal Society of London 155, 459512 (1865). (This article accompanied a December 8, 1864 presentation by Maxwell to the Royal Society.)
A Dynamical Theory of the Electromagnetic Field was the third of James Clerk Maxwells papers concerned with electromagnetism. ...
Undergraduatelevel textbooks  Griffiths, David J. (1998). Introduction to Electrodynamics (3rd ed.). Prentice Hall. ISBN 013805326X.
 Tipler, Paul (2004). Physics for Scientists and Engineers: Electricity, Magnetism, Light, and Elementary Modern Physics (5th ed.). W. H. Freeman. ISBN 0716708108.
 Edward M. Purcell, Electricity and Magnetism (McGrawHill, New York, 1985). ISBN 0070049084.
 Hermann A. Haus and James R. Melcher, Electromagnetic Fields and Energy (PrenticeHall, 1989) ISBN 013249020X.
 Banesh Hoffmann, Relativity and Its Roots (Freeman, New York, 1983). ISBN 0716714787.
 David H. Staelin, Ann W. Morgenthaler, and Jin Au Kong, Electromagnetic Waves (PrenticeHall, 1994) ISBN 0132258714.
 Charles F. Stevens, The Six Core Theories of Modern Physics, (MIT Press, 1995) ISBN 0262691884.
Graduatelevel textbooks  Jackson, John D. (1998). Classical Electrodynamics (3rd ed.). Wiley. ISBN 047130932X.
 Landau, L. D., The Classical Theory of Fields (Course of Theoretical Physics: Volume 2), (ButterworthHeinemann: Oxford, 1987). ISBN 0080181767.
 Maxwell, James C. (1954). A Treatise on Electricity and Magnetism. Dover. ISBN 0486606376.
 Charles W. Misner, Kip S. Thorne, John Archibald Wheeler, Gravitation, (1970) W.H. Freeman, New York; ISBN 0716703440. (Provides a treatment of Maxwell's equations in terms of differential forms.)
Lev Davidovich Landau (Ð›ÐµÌÐ² Ð”Ð°Ð²Ð¸ÌÐ´Ð¾Ð²Ð¸Ñ‡ Ð›Ð°Ð½Ð´Ð°ÌÑƒ) (January 22, 1908 â€“ April 1, 1968) was a prominent Soviet physicist and winner of the Nobel Prize for Physics whose broad field of work included the theory of superconductivity and superfluidity, quantum electrodynamics, nuclear physics and particle physics. ...
Kip S. Thorne Professor Kip Stephen Thorne, Ph. ...
John Archibald Wheeler (born July 9, 1911) is an eminent American theoretical physicist. ...
Vector calculus  H. M. Schey, Div Grad Curl and all that: An informal text on vector calculus, 4th edition (W. W. Norton & Company, 2005) ISBN 0393925161.
See also Theory and Experiment Maxwells equations (sometimes called the Maxwell equations) are the set of four equations, attributed to James Clerk Maxwell, that describe the behavior of both the electric and magnetic fields, as well as their interactions with matter. ...
The wave equation is an important partial differential equation that describes a variety of waves, such as sound waves, light waves and water waves. ...
Computational electromagnetics, computational electrodynamics or electromagnetic modeling refers to the process of modeling the interaction of electromagnetic fields with physical objects and the environment. ...
Electromagnetic radiation can be imagined as a selfpropagating transverse oscillating wave of electric and magnetic fields. ...
Charge conservation is the principle that electric charge can neither be created nor destroyed. ...
Prism splitting light Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific context, electromagnetic radiation of any wavelength [citation needed]. The elementary particle that defines light is the photon. ...
Legend: Î³ = Gamma rays HX = Hard Xrays SX = Soft XRays EUV = Extreme ultraviolet NUV = Near ultraviolet Visible light NIR = Near infrared MIR = Moderate infrared FIR = Far infrared Radio waves: EHF = Extremely high frequency (Microwaves) SHF = Super high frequency (Microwaves) UHF = Ultra high frequency VHF = Very high frequency HF = High...
Table of Opticks, 1728 Cyclopaedia Optics ( appearance or look in ancient Greek) is a branch of physics that describes the behavior and properties of light and the interaction of light with matter. ...
The special theory of relativity was proposed in 1905 by Albert Einstein in his article On the Electrodynamics of Moving Bodies. Some three centuries earlier, Galileos principle of relativity had stated that all uniform motion was relative, and that there was no absolute and welldefined state of rest...
General relativity (GR) is the geometrical theory of gravitation published by Albert Einstein in 1915. ...
The Dynamics of photons in the doubleslit experiment describes the relationship between classical electromagnetic waves and photons, the quantum counterpart of classical electromagnetic waves, in the context of the doubleslit experiment. ...
Photon polarization is the quantum mechanical description of the classical polarized sinusoidal plane electromagnetic wave. ...
The Larmor formula is used to calculate the power radiated by a nonrelativistic electron as it accelerates. ...
The theoretical and experimental justification for the SchrÃ¶dinger equation motivates the discovery of the SchrÃ¶dinger equation, the equation that describes the dynamics of nonrelativistic particles. ...
Applications Full featured rainbow in WrangellSt. ...
In cosmology, the cosmic microwave background radiation (most often abbreviated CMB but occasionally CMBR, CBR or MBR, also referred as relic radiation) is a form of electromagnetic radiation discovered in 1965 that fills the entire universe. ...
// Experiment using a (likely argon) laser. ...
In inertial confinement fusion (ICF), nuclear fusion reactions are initiated by heating and compressing a target â€“ a pellet that most often contains deuterium and tritium â€“ by the use of intense laser or ion beams. ...
Photography is the process of making pictures by means of the action of light. ...
In the NATO phonetic alphabet, Xray represents the letter X. An Xray picture (radiograph) taken by Röntgen An Xray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz...
Xray crystallography is a technique in crystallography in which the pattern produced by the diffraction of Xrays through the closely spaced lattice of atoms in a crystal is recorded and then analyzed to reveal the nature of that lattice. ...
This long range RADAR antenna, known as ALTAIR, is used to detect and track space objects in conjunction with ABM testing at the Ronald Reagan Test Site on the Kwajalein atoll[1]. RADAR is a system that uses radio waves to detect, determine the direction and distance and/or speed...
Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. ...
An Optical Computer is a computer that performs its computation with photons as opposed to the more traditional electronbased computation. ...
{{otheruses4the radiationthe appliancemicrowaves equency = 1 GHz) to 1 mm (300 GHz). ...
Holography (from the Greek, ÎŒÎ»Î¿Ï‚holos whole + Î³ÏÎ±Ï†Î®graphe writing) is the science of producing holograms; it is an advanced form of photography that allows an image to be recorded in three dimensions. ...
A microscope (Greek: (micron) = small + (skopein) = to look at) is an instrument for viewing objects that are too small to be seen by the naked or unaided eye. ...
50 cm refracting telescope at Nice Observatory. ...
This article is in need of attention from an expert on the subject. ...
As the temperature decreases, the peak of the black body radiation curve moves to lower intensities and longer wavelengths. ...
Biographies Einstein redirects here. ...
James Clerk Maxwell (13 June 1831 â€“ 5 November 1879) was a Scottish mathematical physicist, born in Edinburgh. ...
Michael Faraday, FRS (September 22, 1791 â€“ August 25, 1867) was an English chemist and physicist (or natural philosopher, in the terminology of that time) who contributed significantly to the fields of electromagnetism and electrochemistry. ...
Heinrich Hertz Heinrich Rudolf Hertz (February 22, 1857  January 1, 1894), was the German physicist for whom the hertz, the SI unit of frequency, is named. ...
 General subfields within physics  v • d • e   Classical mechanics  Electromagnetism  Thermodynamics  General relativity  Quantum mechanics Physics (from the Greek, (phÃºsis), nature and (phusikÃ©), knowledge of nature) is the science concerned with the discovery and understanding of the fundamental laws which govern matter, energy, space and time. ...
Classical mechanics is a branch of physics which studies the deterministic motion of objects. ...
Electromagnetism is the force observed as static electricity, and causes the flow of electric charge (electric current) in electrical conductors. ...
Thermodynamics (from the Greek thermos meaning heat and dynamics meaning power) is a branch of physics that studies the effects of changes in temperature, pressure, and volume on physical systems at the macroscopic scale by analyzing the collective motion of their particles using statistics. ...
General relativity (GR) is the geometrical theory of gravitation published by Albert Einstein in 1915. ...
Fig. ...
 Particle physics  Condensed matter physics  Atomic, molecular, and optical physics Particles explode from the collision point of two relativistic (100 GeV per nucleon) gold ions in the STAR detector of the Relativistic Heavy Ion Collider. ...
Condensed matter physics is the field of physics that deals with the macroscopic physical properties of matter. ...
Atomic, molecular, and optical physics is the study of mattermatter and lightmatter interactions on the scale of single atoms or structures containing a few atoms. ...
 