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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. Earth–ionosphere waveguide - Wikipedia

    en.wikipedia.org/wiki/Earth–ionosphere_waveguide

    The Earth–ionosphere waveguide [1] is the phenomenon in which certain radio waves can propagate in the space between the ground and the boundary of the ionosphere. Because the ionosphere contains charged particles, it can behave as a conductor. The earth operates as a ground plane, and the resulting cavity behaves as a large waveguide.

  5. Acculturation model - Wikipedia

    en.wikipedia.org/wiki/Acculturation_Model

    In second-language acquisition, the acculturation model is a theory proposed by John Schumann to describe the acquisition process of a second language (L2) by members of ethnic minorities [1] that typically include immigrants, migrant workers, or the children of such groups. [2]

  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. Theories of second-language acquisition - Wikipedia

    en.wikipedia.org/wiki/Theories_of_second...

    Connectionism attempts to model the cognitive language processing of the human brain, using computer architectures that make associations between elements of language, based on frequency of co-occurrence in the language input. [26] Frequency has been found to be a factor in various linguistic domains of language learning. [27]

  8. Learning standards - Wikipedia

    en.wikipedia.org/wiki/Learning_standards

    Learning standards can also take the form of learning objectives and content-specific standards and controlled vocabulary, [4] as well as metadata about content. [5] There are technical standards for encoding these standards that deal with K-12 learning environments, [6] which are separate from those in higher education [7] and private business ...

  9. 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.