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  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. Radio atmospheric signal - Wikipedia

    en.wikipedia.org/wiki/Radio_atmospheric_signal

    A frequency vs. time plot (spectrogram) showing several whistler signals amidst a background of sferics as received at Palmer Station, Antarctica on August 24, 2005.A radio atmospheric signal or sferic (sometimes also spelled "spheric") is a broadband electromagnetic impulse that occurs as a result of natural atmospheric lightning discharges.

  5. Resonator - Wikipedia

    en.wikipedia.org/wiki/Resonator

    A physical system can have as many resonant frequencies as it has degrees of freedom; each degree of freedom can vibrate as a harmonic oscillator.Systems with one degree of freedom, such as a mass on a spring, pendulums, balance wheels, and LC tuned circuits have one resonant frequency.

  6. 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.

  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. Ionospheric storm - Wikipedia

    en.wikipedia.org/wiki/Ionospheric_storm

    The F-region storms occur due to sudden increases of energised electrons instilled into Earth's ionosphere. The F-region is the highest region of the ionosphere. Consisting of the F1 and F2 layers, its distance above the Earth's surface is approximately 200–500 km. [ 7 ] The duration of these storms are around a day and reoccur every ...

  9. Cherenkov radiation - Wikipedia

    en.wikipedia.org/wiki/Cherenkov_radiation

    Cherenkov radiation glowing in the core of the Advanced Test Reactor at Idaho National Laboratory. Cherenkov radiation (/ tʃ ə ˈ r ɛ ŋ k ɒ f / [1]) is electromagnetic radiation emitted when a charged particle (such as an electron) passes through a dielectric medium (such as distilled water) at a speed greater than the phase velocity (speed of propagation of a wavefront in a medium) of ...