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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.
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 ...
Images featured on the Astronomy Picture of the Day (APOD) web site may be copyrighted. [3] The National Space Science Data Center (NSSDC) site has been known to host copyrighted content .
Thus, Earth Day was eventually established and began on April 22, 1970. April 22 was chosen as the national date for Earth Day because it best fit in college schedules between spring break and ...
For Earth Day on April 22, interesting facts including who invented it, why it's on that date, and how it turned into a global movement.
The dispersion characteristics of the Earth-ionospheric waveguide can be used for locating thunderstorm activity by measurements of the difference of the group time delay of lightning signals at adjacent frequencies up to distances of 10000 km. [7] The Schumann resonances allow to determine the global lightning activity. [9]
The Earth Day Special is a television special revolving around Earth Day that aired on ABC on April 22, 1990. Sponsored by Time Warner , the two-hour special featured an ensemble cast addressing concerns about pollution , deforestation , and other environmental ills.
For the third annual Call to Earth Day, schools around the world took action to protect the environment.