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  2. Radiant energy - Wikipedia

    en.wikipedia.org/wiki/Radiant_energy

    In physics, and in particular as measured by radiometry, radiant energy is the energy of electromagnetic [1] and gravitational radiation. As energy, its SI unit is the joule (J). The quantity of radiant energy may be calculated by integrating radiant flux (or power ) with respect to time .

  3. Electromagnetic radiation - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_radiation

    EMR of lower energy ultraviolet or lower frequencies (i.e., near ultraviolet, visible light, infrared, microwaves, and radio waves) is non-ionizing because its photons do not individually have enough energy to ionize atoms or molecules or to break chemical bonds. The effect of non-ionizing radiation on chemical systems and living tissue is ...

  4. Radiative transfer - Wikipedia

    en.wikipedia.org/wiki/Radiative_transfer

    Radiative transfer (also called radiation transport) is the physical phenomenon of energy transfer in the form of electromagnetic radiation.The propagation of radiation through a medium is affected by absorption, emission, and scattering processes.

  5. Radiative zone - Wikipedia

    en.wikipedia.org/wiki/Radiative_zone

    A radiative zone is a layer of a star's interior where energy is primarily transported toward the exterior by means of radiative diffusion and thermal conduction, rather than by convection. [1] Energy travels through the radiative zone in the form of electromagnetic radiation as photons .

  6. Radiation - Wikipedia

    en.wikipedia.org/wiki/Radiation

    (E is Energy; h is the Planck constant; c is the speed of light; λ is wavelength.) When an X-ray photon collides with an atom, the atom may absorb the energy of the photon and boost an electron to a higher orbital level, or if the photon is extremely energetic, it may knock an electron from the atom altogether, causing the atom to ionize.

  7. Electromagnetic spectrum - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_spectrum

    In frequency (and thus energy), UV rays sit between the violet end of the visible spectrum and the X-ray range. The UV wavelength spectrum ranges from 399 nm to 10 nm and is divided into 3 sections: UVA, UVB, and UVC. UV is the lowest energy range energetic enough to ionize atoms, separating electrons from them, and thus causing chemical reactions.

  8. Thermal radiation - Wikipedia

    en.wikipedia.org/wiki/Thermal_radiation

    Radiant heat panel for testing precisely quantified energy exposures at National Research Council, near Ottawa, Ontario, Canada. Thermal radiation plays a crucial role in human comfort, influencing perceived temperature sensation. Various technologies have been developed to enhance thermal comfort, including personal heating and cooling devices.

  9. Radiance - Wikipedia

    en.wikipedia.org/wiki/Radiance

    Energy of electromagnetic radiation. Radiant energy density: w e: joule per cubic metre J/m 3: M⋅L −1 ⋅T −2: Radiant energy per unit volume. Radiant flux: Φ e [nb 2] watt: W = J/s M⋅L 2 ⋅T −3: Radiant energy emitted, reflected, transmitted or received, per unit time. This is sometimes also called "radiant power", and called ...