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  Encyclopedia of Keywords > Encyclopedia of Finance. > Technology > Energy > Photons   Michael Charnine

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  1. Photons, the uncharged particles of light, can also be emitted by radioactive nuclides, but can also be generated by x-ray devices.
  2. Photons are the closest thing to "pure energy" you can get -- they have zero mass and travel at the speed of light. (Web site)
  3. Photons are particles, or more properly quanta, of light and a light beam is made up of what can be thought of as a stream of photons. (Web site)
  4. Photons are also created when a charged particle, such as an electron or proton, is accelerated, as for example happens in a radio transmitter antenna.
  5. A: Photons are particles of light, and do not have mass (unlike, say, electrons), which is why they can travel at the speed of light in the first place.

Light Source

  1. Materials such as phosphors or phosphorogens are activated from a light source to emit the light in the form of photons of light.
  2. Hence the whole reason why we can only send out uncharged photons from a light source is that we are only sending them one way. (Web site)

Photon Mapping

  1. With photon mapping, light packets (photons) are sent out into the scene from the light source.


  1. The creation of a much more massive pair, like a proton and antiproton, requires photons with energy of more than 1.88 GeV (hard gamma ray photons). (Web site)
  2. The Pion or Pi meson is proposed to be three photons in the same general type orbits (repeat motion being wavelength) as the proton. (Web site)
  3. We define the baryon number of a proton to be 1 and that of electrons and photons to be zero.

Electron Moves

  1. This conservation is achieved by the emission of photons when an electron moves from a higher potential orbital energy to a lower potential orbital energy.

Electric Field

  1. In the dynamic case the electric field is accompanied by a magnetic field, by a flow of energy, and by real photons. (Web site)
  2. In the static case, an electric field is composed of virtual photons being exchanged by the charged particle(s) creating the field.
  3. The apparent paradox can be explained by the formation of virtual photons in the electric field generated by the electron. (Web site)

Opposite Directions

  1. So the two photons must speed off in opposite directions with opposite spin. (Web site)
  2. This is a demonstration of the action at a distance observed of two photons moving away from each other in opposite directions after creation.

Energetic Photons

  1. These are the most energetic photons, having no defined lower limit to their wavelength. (Web site)
  2. They can penetrate matter, ionize the material which they traverse and emit energetic photons (e.g. (Web site)


  1. The rays that go undeflected indicate no charge and are therefore energetic photons or γ (gamma) rays.
  2. LQG predicts that more energetic photons should travel ever so slightly faster than less energetic photons. (Web site)
  3. Real electron-positron pairs are created when energetic photons, represented by the electromagnetic field, interact with these fields. (Web site)

Electromagnetic Wave

  1. The photons have momentum as well as energy, and the momentum had to be where k is the wavenumber of the electromagnetic wave.
  2. The ability of an electromagnetic wave (photons) to ionize an atom or molecule depends on its frequency.

Wave-Particle Duality

  1. In 1923 de Broglie proposed that wave-particle duality applied not only to photons but to electrons and every other physical system. (Web site)
  2. Photons are used to describe the wave-particle duality of light.


  1. In contrast to the case of baryons or leptons, meson number is not conserved: like photons, mesons can be created or destroyed in arbitrary numbers.
  2. Because momentum is conserved, in the plane perpendicular to the beam, these photons should come out in opposite directions.
  3. Bosons are not conserved - for example, billions of photons are created every time you turn on a light, and disappear when they are absorbed by atoms. (Web site)

Invariant Mass

  1. This mass is called the invariant mass of the pair of photons together. (Web site)
  2. So the invariant mass of the photons is equal to the pion's rest energy. (Web site)


  1. This means that protons, electrons, neutrons and possibly their antimatter counterparts can be converted to photons and then converted to another particle. (Web site)
  2. Some of the photons became quarks, and then the quarks formed neutrons and protons. (Web site)
  3. Scientists tried to create a similar theory of nuclear forces based on the interaction of protons and neutrons with some particle analogous to photons. (Web site)

Wave-Like Properties

  1. De Broglie proposed that electrons, as photons (particles of light) manifested both particle-like and wave-like properties. (Web site)

Matter Waves

  1. It is tempting to treat a phonon with wave vector k as though it has a momentum ℏ k, by analogy to photons and matter waves.


  1. The particles may be atoms, photons or a flux of elementary particles. (Web site)
  2. For example, the amount of light (photons) striking a single square centimeter of a detector in one second is its flux.
  3. The same nucleus is subject both to a flux of nucleons and photons, so an equilibrium is reached where mass builds up at particular nuclear species. (Web site)

Unit Time

  1. Flux The flow of photons, particles, or energy per unit time through an imaginary sphere of unit cross-sectional area.
  2. An actinometer is a chemical system or physical device which determines the number of photons in a beam integrally or per unit time.

Black Hole

  1. At a distance it looks like the mass of the black hole is evaporating by emitting photons (Hawking radiation).
  2. The evaporation of a black hole is a process dominated by photons, which are their own antiparticles and are uncharged.
  3. But the black hole will eventually evaporate, leaving only photons, gravitons and other elementary particles as products of the decay. (Web site)

Gravitational Redshift

  1. The two previous effects, the gravitational redshift and the deflection of light, are derived from nul-geodesics, the paths of photons.
  2. The stronger the gravitational field, the more energy the photons lose because of this gravitational redshift.


  1. These photons (bits of sunlight) knock electrons loose from the atoms inside the semiconductor.
  2. Sunlight is composed of photons, or particles of solar energy. (Web site)
  3. NREL researchers now want to add a third semiconductor layer to the cell, with an even lower band gap responsive to lower energy photons in sunlight. (Web site)


  1. Leptons, photons and W and Z bosons do not have color charge and therefore do not participate in strong interactions. (Web site)
  2. Since photons have no charge, the term is zero for a photon.
  3. Charge implies the exchange of photons between charged particles. (Web site)

Colour Charge

  1. Whereas photons do not interact among themselves—because they are not electrically charged—gluons do carry colour charge. (Web site)


  1. As the universe expands, the CMB photons are redshifted, cooling the radiation inversely proportional to the Universe's scale length.
  2. As the universe expands, the CMB photons are redshifted, making the radiation's temperature inversely proportional to the Universe's scale length.
  3. The Big Bang theory predicted the existence of the cosmic microwave background radiation or CMB which is composed of photons emitted during baryogenesis.

Cosmic Microwave Background

  1. About 99% of the photons in the universe (the cosmic microwave background) are the result of Big Bang annihilations. (Web site)
  2. Most importantly, this means that the photons that compose the cosmic microwave background are a picture of the universe during this epoch.
  3. The effect is also observed when photons from the cosmic microwave background move through the hot gas surrounding a galaxy cluster. (Web site)


  1. Bosons are force carriers like photons of light and fermions are the matter we can touch.
  2. An example of an entity that is quantized is the energy transfer of elementary particles of matter (called fermions) and of photons and other bosons. (Web site)
  3. The force-carrying bosons, such as photons and gluons, should be paired with fermions, such as particles called photinos and gluinos. (Web site)


  1. These photons are still interacting frequently with charged protons, electrons and (eventually) nuclei, and continue to do so for the next 300,000 years.
  2. Before decoupling occurs most of the photons in the universe are interacting with electrons and protons in the photon-baryon fluid.
  3. Electrons can gain energy by interacting with photons. (Web site)


  1. As a result of this, when matter and antimatter come together, they annihilate, producing energy in the form of light (photons). (Web site)
  2. The reverse process, pair production, is the dominant mechanism by which high-energy photons such as gamma ray s lose energy while passing through matter. (Web site)
  3. Radiation Length, High-energy electrons predominantly lose energy in matter by bremsstrahlung, and high-energy photons by e + e - pair production. (Web site)

Integer Spin

  1. The modern view on this is that photons are, by virtue of their integer spin, bosons (as opposed to fermions with half-integer spin). (Web site)
  2. For particles with integer spin, including photons, the wave function does not change sign. (Web site)

Carrier Particles

  1. Its carrier particles are called photons, which are not really particles, but massless discrete units of energy. (Web site)

Quantum Theory

  1. The electromagnetic properties of superconductors are explained in quantum theory by assuming that force-carrying particles, known as photons, gain mass. (Web site)
  2. For instance, in quantum theory, the energy of light is quantized: a given quantity of light consists of a finite number of energy packets called photons. (Web site)
  3. In the midst of this revolution, Einstein contributed seminal papers on the statistics of quantum theory and the stimulated emission of photons from atoms. (Web site)

Quantum Optics

  1. A. Quantum optics is a field of quantum physics that deals specifically with the interaction of photons with matter.
  2. Quantum Optics: Quantum optics is a branch of quantum physics that focuses primarily on the behavior of light, or photons.
  3. Light is made up of particles called photons and hence inherently is "grainy" (quantized); quantum optics is the study of the nature and effects of this.


  1. Electrons, photons, and probably neutrinos (elementary particles all) are more stable than protons.
  2. Instead, they should glow slightly with "Hawking radiation", consisting of photons, neutrinos, and to a lesser extent all sorts of massive particles. (Web site)
  3. Neutrinos, on the other hand, have no electric charge, so they cannot absorb or produce photons. (Web site)


  1. Our particle content now includes electrons, muons, photons, and Z bosons.


  1. The photons emitted right after the recombination can now travel undisturbed and are those that we see in the cosmic microwave background (CMB) radiation.
  2. Because electromagnetic (EM) radiation can be considered to be a stream of photons, radiant energy can be viewed as the energy carried by these photons.
  3. Collimation The alignment of the direction of the photons, so the beam of radiation can be directed at a well-defined part of a target material. (Web site)

Gamma Radiation

  1. The heavy electrons absorb energy from the gamma radiation and re-radiate it as photons (38, 40) at a lower energy and frequency. (Web site)
  2. External beam therapy can be done with photons (gamma radiation), electrons, or protons.
  3. Gamma radiation is composed of high-energy photons.


  1. Note that these decay laws do not apply to the positronium (all charges are zero), so it is allowed to decay into photons, as it does. (Web site)


  1. At the the "moment" right after annihilation has two photons with the same mass and approximate position as the two particles that preceded them.
  2. A positronium `atom' decays to form two photons by annihilation. (Web site)
  3. Thus, matter can be created out of two photons (this is the process inverse to annihilation).

Zero Mass

  1. Photons have zero mass and zero electric charge, but they do carry energy, momentum and angular momentum. (Web site)

Pure Energy

  1. When matter and antimatter come in contact they are both instantaneously converted into pure energy, in the form of photons.
  2. These photons are pure energy given off by the nucleus in its process of achieving stability. (Web site)

Rayleigh Scattering

  1. When light is scattered from an atom or molecule, most photons are elastically scattered (Rayleigh scattering). (Web site)


  1. Electrons and photons then lose energy via scattering until they are absorbed by atoms. (Web site)
  2. A second demonstration of the particlelike behavior of photons is provided by the scattering of an x-ray photon from an electron bound in an atom.
  3. This is called the Compton wavelength (after Arthur Compton) because it appears in the theory of Compton scattering - the scattering of photons by electrons. (Web site)

Light Energy

  1. The input surface of an image intensifier that absorbs light energy (photons) and converts it to electrical energy (electrons).

Energy Level

  1. Electrons can be moved from one energy level to another by collisions among atoms or by absorption of photons.
  2. Photons can also be absorbed by nuclei, atoms or molecules, provoking transitions between their energy level s. (Web site)

Energy Levels

  1. The energy of these orbits is quantized and electrons must absorb or release energy (photons) at certain wavelengths to move between energy levels.
  2. The energy levels of the electron determine the photons that the atom will absorb or emit, allowing the powerful scientific tool of spectral analysis.
  3. A histogram representing the frequency distribution of the energy levels of detected X-ray photons is formed. (Web site)

Event Horizon

  1. Sometimes these photons will form in the region of the event horizon of a black hole. (Web site)
  2. Nothing -- neither particles nor photons (i.e., electromagnetic radiation) -- can escape from inside the event horizon.

Photon Sphere

  1. The photon sphere is a spherical boundary of zero thickness such that photons moving along tangents to the sphere will be trapped in a circular orbit. (Web site)


  1. Encyclopedia of Finance. > Technology > Energy
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Related Keywords

    * Atom * Atoms * Bosons * Charge Carriers * Compton Effect * Einstein * Electromagnetic Field * Electromagnetic Fields * Electromagnetic Force * Electromagnetic Interaction * Electromagnetic Interactions * Electromagnetic Radiation * Electron * Electron-Hole Pairs * Electrons * Emission * Energies * Energy * Frequencies * Frequency * Gamma Rays * Gluons * Gravitons * Higher Energies * Interaction * Interactions * Light * Light Particles * Light Photons * Mass * Massless Particles * Momentum * Particle * Particles * Phonons * Photoelectric Effect * Photon * Positron * Positrons * Protons * Qed * Quanta * Quantum Electrodynamics * Quarks * Rays * Scattered * Scattered Photons * Travel * Virtual Particles * Virtual Photons * Visible Light * Wavelength * Wavelengths * X-Rays * Zitterbewegung
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  Originally created: August 01, 2010.
  Links checked: June 24, 2013.
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