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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 ...
Materials based on Hubble Space Telescope data may be copyrighted if they are not explicitly produced by the STScI. See also {{PD-Hubble}} and {{Cc-Hubble}} . The SOHO (ESA & NASA) joint project implies that all materials created by its probe are copyrighted and require permission for commercial non-educational use.
To cause resonance, the phase of a sinusoidal wave after a round trip must be equal to the initial phase so the waves self-reinforce. The condition for resonance in a resonator is that the round trip distance, 2 d {\displaystyle 2d\,} , is equal to an integer number of wavelengths λ {\displaystyle \lambda \,} of the wave:
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.
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. [1]: 26‑1 As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. [2]
Electrical resonance occurs in an electric circuit at a particular resonant frequency when the impedances or admittances of circuit elements cancel each other. In some circuits, this happens when the impedance between the input and output of the circuit is almost zero and the transfer function is close to one.
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 ...