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• Electromagnetic_radiation abstract "Electromagnetic radiation (EM radiation or EMR) is a fundamental phenomenon of electromagnetism, behaving as waves propagating through space, and also as photon particles traveling through space, carrying radiant energy. In a vacuum, it propagates at a characteristic speed, the speed of light, normally in straight lines. EMR is emitted and absorbed by charged particles. As an electromagnetic wave, it has both electric and magnetic field components, which oscillate in a fixed relationship to one another, perpendicular to each other and perpendicular to the direction of energy and wave propagation.In classical physics, EMR is considered to be produced when charged particles are accelerated by forces acting on them. Electrons are responsible for emission of most EMR because they have low mass, and therefore are easily accelerated by a variety of mechanisms. Quantum processes can also produce EMR, such as when atomic nuclei undergo gamma decay, and processes such as neutral pion decay.EMR carries energy—sometimes called radiant energy—through space continuously away from the source (this is not true of the near-field part of the EM field). EMR also carries both momentum and angular momentum. These properties may all be imparted to matter with which it interacts. EMR is produced from other types of energy when created, and it is converted to other types of energy when it is destroyed. The electromagnetic spectrum, in order of increasing frequency and decreasing wavelength, can be divided, for practical engineering purposes, into radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays. The eyes of various organisms sense a relatively small range of frequencies of EMR called the visible spectrum or light; what is visible depends somewhat on which species of organism is under consideration. Higher frequencies (shorter wavelengths) correspond to proportionately more energy carried by each photon, according to the well-known law E=hν, where E is the energy per photon, ν is the frequency carried by the photon, and h is Planck's constant. For instance, a single gamma ray photon carries far more energy than a single photon of visible light.The photon is the quantum of the electromagnetic interaction, and is the basic "unit" or constituent of all forms of EMR. The quantum nature of light becomes more apparent at high frequencies (thus high photon energy). Such photons behave more like particles than lower-frequency photons do.Electromagnetic waves in free space must be solutions of Maxwell's electromagnetic wave equation. Two main classes of solutions are known, namely plane waves and spherical waves. The plane waves may be viewed as the limiting case of spherical waves at a very large (ideally infinite) distance from the source. Both types of waves can have a waveform which is an arbitrary time function (so long as it is sufficiently differentiable to conform to the wave equation). As with any time function, this can be decomposed by means of Fourier analysis into its frequency spectrum, or individual sinusoidal components, each of which contains a single frequency, amplitude, and phase. Such a component wave is said to be monochromatic. A monochromatic electromagnetic wave can be characterized by its frequency or wavelength, its peak amplitude, its phase relative to some reference phase, its direction of propagation, and its polarization.Electromagnetic radiation is associated with EM fields that are free to propagate themselves without the continuing influence of the moving charges that produced them, because they have achieved sufficient distance from those charges. Thus, EMR is sometimes referred to as the far field. In this language, the near field refers to EM fields near the charges and current that directly produced them, as for example with simple magnets and static electricity phenomena. In EMR, the magnetic and electric fields are each induced by changes in the other type of field, thus propagating itself as a wave. This close relationship assures that both types of fields in EMR stand in phase and in a fixed ratio of intensity to each other, with maxima and nodes in each found at the same places in space.The effects of EMR upon biological systems (and also to many other chemical systems, under standard conditions) depend both upon the radiation's power and frequency. For lower frequencies of EMR up to those of visible light (i.e., radio, microwave, infrared), the damage done to cells and also to many ordinary materials under such conditions is determined mainly by heating effects, and thus by the radiation power. By contrast, for higher frequency radiations at ultraviolet frequencies and above (i.e., X-rays and gamma rays) the damage to chemical materials and living cells by EMR is far larger than that done by simple heating, due to the ability of single photons in such high frequency EMR to damage individual molecules chemically.".
• Electromagnetic_radiation thumbnail Onde_electromagnetique.svg?width=300.
• Electromagnetic_radiation wikiPageExternalLink Wilhelm_Eduard_Weber),.
• Electromagnetic_radiation wikiPageExternalLink electromagnetic-waves.
• Electromagnetic_radiation wikiPageExternalLink index.php?title=An_Introduction_to_The_Wigner_Distribution_in_Geometric_Optics.
• Electromagnetic_radiation wikiPageExternalLink electromagneticSpectrum-en.html.
• Electromagnetic_radiation wikiPageExternalLink einleitung_hauptseite_uk.html.
• Electromagnetic_radiation wikiPageExternalLink EM_Radiation.html.
• Electromagnetic_radiation wikiPageExternalLink ch11.html.
• Electromagnetic_radiation wikiPageExternalLink www.physnet.org.
• Electromagnetic_radiation wikiPageExternalLink m210.pdf.
• Electromagnetic_radiation wikiPageExternalLink introduction-to-light.
• Electromagnetic_radiation wikiPageID "9426".
• Electromagnetic_radiation wikiPageRevisionID "606640902".
• Electromagnetic_radiation about "yes".
• Electromagnetic_radiation by "no".
• Electromagnetic_radiation hasPhotoCollection Electromagnetic_radiation.
• Electromagnetic_radiation label "Electromagnetic radiation".
• Electromagnetic_radiation onlinebooks "no".
• Electromagnetic_radiation others "no".
• Electromagnetic_radiation subject Category:Electromagnetic_radiation.
• Electromagnetic_radiation subject Category:Radiation.
• Electromagnetic_radiation comment "Electromagnetic radiation (EM radiation or EMR) is a fundamental phenomenon of electromagnetism, behaving as waves propagating through space, and also as photon particles traveling through space, carrying radiant energy. In a vacuum, it propagates at a characteristic speed, the speed of light, normally in straight lines. EMR is emitted and absorbed by charged particles.".
• Electromagnetic_radiation label "Electromagnetic radiation".
• Electromagnetic_radiation label "Elektromagnetische Welle".
• Electromagnetic_radiation label "Elektromagnetische straling".
• Electromagnetic_radiation label "Promieniowanie elektromagnetyczne".
• Electromagnetic_radiation label "Radiación electromagnética".
• Electromagnetic_radiation label "Radiazione elettromagnetica".
• Electromagnetic_radiation label "Radiação eletromagnética".
• Electromagnetic_radiation label "Rayonnement électromagnétique".
• Electromagnetic_radiation label "Электромагнитное излучение".
• Electromagnetic_radiation label "موجة كهرومغناطيسية".
• Electromagnetic_radiation label "电磁波".
• Electromagnetic_radiation label "電磁波".
• Electromagnetic_radiation sameAs Elektromagnetické_záření.
• Electromagnetic_radiation sameAs Elektromagnetische_Welle.
• Electromagnetic_radiation sameAs Ηλεκτρομαγνητική_ακτινοβολία.
• Electromagnetic_radiation sameAs Radiación_electromagnética.
• Electromagnetic_radiation sameAs Erradiazio_elektromagnetiko.
• Electromagnetic_radiation sameAs Rayonnement_électromagnétique.
• Electromagnetic_radiation sameAs Radiasi_elektromagnetik.
• Electromagnetic_radiation sameAs Radiazione_elettromagnetica.
• Electromagnetic_radiation sameAs 電磁波.
• Electromagnetic_radiation sameAs 전자기파.
• Electromagnetic_radiation sameAs Elektromagnetische_straling.
• Electromagnetic_radiation sameAs Promieniowanie_elektromagnetyczne.
• Electromagnetic_radiation sameAs Radiação_eletromagnética.
• Electromagnetic_radiation sameAs m.02kzh.
• Electromagnetic_radiation sameAs Q11386.
• Electromagnetic_radiation sameAs Q11386.
• Electromagnetic_radiation wasDerivedFrom Electromagnetic_radiation?oldid=606640902.
• Electromagnetic_radiation depiction Onde_electromagnetique.svg.
• Electromagnetic_radiation isPrimaryTopicOf Electromagnetic_radiation.