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  2. Electromagnetic spectrum - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_spectrum

    The higher energy (shortest wavelength) ranges of UV (called "vacuum UV") are absorbed by nitrogen and, at longer wavelengths, by simple diatomic oxygen in the air. Most of the UV in the mid-range of energy is blocked by the ozone layer, which absorbs strongly in the important 200–315 nm range, the lower energy part of which is too long for ...

  3. Electromagnetic radiation - Wikipedia

    en.wikipedia.org/wiki/Electromagnetic_radiation

    The energy required for this is always larger than about 10 electron volt (eV) corresponding with wavelengths smaller than 124 nm (some sources suggest a more realistic cutoff of 33 eV, which is the energy required to ionize water). This high end of the ultraviolet spectrum with energies in the approximate ionization range, is sometimes called ...

  4. Absorption (electromagnetic radiation) - Wikipedia

    en.wikipedia.org/wiki/Absorption_(electromagnetic...

    By recording the attenuation of light for various wavelengths, an absorption spectrum can be obtained. In physics, absorption of electromagnetic radiation is how matter (typically electrons bound in atoms) takes up a photon's energy—and so transforms electromagnetic energy into internal energy of the absorber (for example, thermal energy). [1]

  5. Radiant energy - Wikipedia

    en.wikipedia.org/wiki/Radiant_energy

    In geophysics, most atmospheric gases, including the greenhouse gases, allow the Sun's short-wavelength radiant energy to pass through to the Earth's surface, heating the ground and oceans. The absorbed solar energy is partly re-emitted as longer wavelength radiation (chiefly infrared radiation), some of which is absorbed by the atmospheric ...

  6. Planck's law - Wikipedia

    en.wikipedia.org/wiki/Planck's_law

    The much smaller gap in ratio of wavelengths between 0.1% and 0.01% (1110 is 22% more than 910) than between 99.9% and 99.99% (113374 is 120% more than 51613) reflects the exponential decay of energy at short wavelengths (left end) and polynomial decay at long. Which peak to use depends on the application.

  7. Stokes shift - Wikipedia

    en.wikipedia.org/wiki/Stokes_shift

    Stokes fluorescence is the emission of a longer-wavelength photon (lower frequency or energy) by a molecule that has absorbed a photon of shorter wavelength (higher frequency or energy). [6] [7] [8] Both absorption and radiation (emission) of energy are distinctive for a particular molecular structure. If a material has a direct bandgap in the ...

  8. Ultraviolet catastrophe - Wikipedia

    en.wikipedia.org/wiki/Ultraviolet_catastrophe

    The ultraviolet catastrophe, also called the Rayleigh–Jeans catastrophe, was the prediction of late 19th century and early 20th century classical physics that an ideal black body at thermal equilibrium would emit an unbounded quantity of energy as wavelength decreased into the ultraviolet range.

  9. Matter wave - Wikipedia

    en.wikipedia.org/wiki/Matter_wave

    To find the wavelength equivalent to a moving body, de Broglie [2]: 214 set the total energy from special relativity for that body equal to hν: = = (Modern physics no longer uses this form of the total energy; the energy–momentum relation has proven more useful.)