Kennelly-Heaviside layer

Kennelly-Heaviside layer

The Kennelly-Heaviside layer, also known as the E region or simply the Heaviside layer, is a layer of ionised gas occurring at 90–150 km above the ground — one of several layers in the Earth's ionosphere. It reflects medium-frequency radio waves, and because of this reflection radio waves can be propagated beyond the horizon.

Propagation is affected by time of day. During the daytime the solar wind presses this layer closer to the Earth, thereby limiting how far it can reflect radio waves. On the night side of the Earth, the solar wind drags the ionosphere further away, thereby greatly increasing the range which radio waves can travel by reflection, called skywave. The extent of the effect is further influenced by the season (because of the differing distance between Earth and the Sun), and the amount of sunspot activity.

History

Its existence was predicted in 1902 independently and almost simultaneously by the American electrical engineer Arthur Edwin Kennelly (1861-1939) and the British physicist Oliver Heaviside (1850-1925). However, it was not until 1924 that its existence was detected by Edward V. Appleton.

In 1899, Nikola Tesla, in his Colorado Springs experiments, transmitted extremely low frequency electromagnetic waves between the earth and ionosphere, up to the Kennelly-Heaviside layer (Grotz, 1997). Tesla made mathematical calculations and computations based on his experiments. He predicted the resonance frequency of this area within 15% of modern accepted experimental value. (Corum, 1986) In the 1950s, researchers confirmed the resonance frequency was at the low range 6.8 Hz.

References

* Corum, J. F., and Corum, K. L., "A Physical Interpretation of the Colorado Springs Data". Proceedings of the Second International Tesla Symposium. Colorado Springs, Colorado, 1986.
* Grotz, Toby, "The True Meaning of Wireless Transmission of power". Tesla : A Journal of Modern Science, 1997.

Cultural impact

The "Heaviside layer" is used as a symbol for heaven (in the afterlife sense) in Andrew Lloyd Webber's musical "Cats". This reference is based on a quote found in a letter written by T. S. Eliot, whose book "Old Possum's Book of Practical Cats" forms the basis of the musical. In the musical, one cat is chosen each year by Old Deuteronomy to go to the Heaviside Layer and begin a new life. In the song "The Journey to the Heaviside Layer", it is stated that the Heaviside Layer is "past the Russell Hotel" and "past the Jellicle moon", indicating that it is very far away and difficult to access.

In the end of the musical, Grizabella is chosen to go the Heaviside Layer. She does so by ascending on a flying tyre until she reaches a structure resembling clouds, into which she disappears.

The "Heaviside Layer" is another name for the Ionosphere. There are two kinds of ions, anions and "cations". This reference may be a scientific pun by T. S. Eliot.


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  • Kennelly-Heaviside layer — [ken′əl ē hev′ē sīd΄] n. [after A. Kennelly (1861 1939), U.S. electrical engineer & O. Heaviside (1850 1925), Eng physicist] E LAYER …   English World dictionary

  • Kennelly-Heaviside layer — noun a region of the ionosphere (from 50 to 90 miles up) that reflects radio waves of medium length • Syn: ↑Heaviside layer, ↑E layer, ↑E region • Instance Hypernyms: ↑region, ↑part • Part Holonyms: ↑ …   Useful english dictionary

  • Kennelly-Heaviside layer — /ken l ee hev ee suyd /. Physics. See E layer. [1920 25; named after Arthur Edwin Kennelly (1861 1939), U.S. electrical engineer, and O. HEAVISIDE] * * * …   Universalium

  • Heaviside layer — A layer of ionized particles that surrounds the earth. The layer, also called the E layer, has ionization of around 106 free electrons. The layer is found at a height of around 60 to 90 miles (100 150 km), but its height varies according to the… …   Aviation dictionary

  • Heaviside layer — /ˈhɛvisaɪd leɪə/ (say heveesuyd layuh) noun the lower region, or regions, of the ionosphere chiefly responsible for the reflection of radio waves of certain frequencies, thus making long distance radio communication possible. Also, E layer,… …  

  • Kennelly-Heaviside-Schicht — Ionosphärenschichten (engl. Layer) in Abhängigkeit von der Tageszeit Die Kennelly Heaviside Schicht, auch E Schicht genannt, ist ein Teil der Ionosphäre der Erde. Sie ist eine der Schichten der Ionosphäre an denen kurzwellige Radiosignale… …   Deutsch Wikipedia

  • Capa Kennelly-Heaviside — Saltar a navegación, búsqueda Capas de la ionosfera terrestre. La capa E aparece tanto de día como de noche. La capa Kennelly Heaviside, también conocida como región E o simplemente capa Heaviside , es una capa de gas ioniza …   Wikipedia Español

  • Heaviside layer — (also Heaviside–Kennelly layer) noun another name for E layer. Origin early 20th cent.: named after the English physicist Oliver Heaviside and the American engineer Arthur E. Kennelly …   English new terms dictionary

  • Heaviside layer — n. (in full Heaviside Kennelly layer) = E LAYER. Etymology: O. Heaviside, Engl. physicist d. 1925, and A. E. Kennelly, US physicist d. 1939 …   Useful english dictionary

  • Kennelly — is a surname and may refer to:* Ardyth Kennelly, American novelist * Arthur Edwin Kennelly, American engineer * Barbara B. Kennelly, Connecticut Representative * Brendan Kennelly, Irish poet and novelist * Keala Kennelly, American surfer * Martin …   Wikipedia

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