enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Schumann resonances - Wikipedia

    en.wikipedia.org/wiki/Schumann_resonances

    The global electromagnetic resonance phenomenon is named after physicist Winfried Otto Schumann who predicted it mathematically in 1952. Schumann resonances are the principal background in the part of the electromagnetic spectrum [2] from 3 Hz through 60 Hz [3] and appear as distinct peaks at extremely low frequencies around 7.83 Hz (fundamental), 14.3, 20.8, 27.3, and 33.8 Hz.

  3. Extremely low frequency - Wikipedia

    en.wikipedia.org/wiki/Extremely_low_frequency

    The fundamental Schumann resonance is at approximately 7.83 Hz, the frequency at which the wavelength equals the circumference of the Earth, and higher harmonics occur at 14.1, 20.3, 26.4, and 32.4 Hz, etc. Lightning strikes excite these resonances, causing the Earth–ionosphere cavity to "ring" like a bell, resulting in a peak in the noise ...

  4. Normal mode - Wikipedia

    en.wikipedia.org/wiki/Normal_mode

    If the matrix on the left is invertible, the unique solution is the trivial solution (A 1, A 2) = (x 1, x 2) = (0, 0). The non trivial solutions are to be found for those values of ω whereby the matrix on the left is singular; i.e. is not invertible. It follows that the determinant of the matrix must be equal to 0, so:

  5. Winfried Otto Schumann - Wikipedia

    en.wikipedia.org/wiki/Winfried_Otto_Schumann

    Winfried Otto Schumann (May 20, 1888 – September 22, 1974) was a German physicist and electrical engineer who predicted the Schumann resonances, a series of low-frequency resonances caused by lightning discharges in the atmosphere.

  6. Absorption band - Wikipedia

    en.wikipedia.org/wiki/Absorption_band

    Absorptions bands in the Earth's atmosphere created by greenhouse gases and the resulting effects on transmitted radiation.. In spectroscopy, an absorption band is a range of wavelengths, frequencies or energies in the electromagnetic spectrum that are characteristic of a particular transition from initial to final state in a substance.

  7. Waveguide (radio frequency) - Wikipedia

    en.wikipedia.org/wiki/Waveguide_(radio_frequency)

    In radio-frequency engineering and communications engineering, a waveguide is a hollow metal pipe used to carry radio waves. [1] This type of waveguide is used as a transmission line mostly at microwave frequencies, for such purposes as connecting microwave transmitters and receivers to their antennas, in equipment such as microwave ovens, radar sets, satellite communications, and microwave ...

  8. Ferroresonance in electricity networks - Wikipedia

    en.wikipedia.org/wiki/Ferroresonance_in...

    Ferroresonance or nonlinear resonance is a rare [1] type of resonance in electric circuits which occurs when a circuit containing a nonlinear inductance is fed from a source that has series capacitance, and the circuit is subjected to a disturbance such as opening of a switch. [2]

  9. Resonance (particle physics) - Wikipedia

    en.wikipedia.org/wiki/Resonance_(particle_physics)

    Thus, the lifetime of a particle is the direct inverse of the particle's resonance width. For example, the charged pion has the second-longest lifetime of any meson, at 2.6033 × 10 −8 s. [2] Therefore, its resonance width is very small, about 2.528 × 10 −8 eV or about 6.11 MHz. Pions are generally not considered as "resonances".