|Copyright © Klaus Piontzik
|Now the previous considerations allow a first calculation of a wave that builds up, as the earth, around a sphere. Still, it must be considered that the wave propagation takes place linear and not along the curved surface of the ball.
|After the Huygens-Fresnel
principle the points A,
B, C serve so as source points of the standing wave (blue)
Electromagnetic waves propagate spherically from one point. (red)
If point B is the starting point so the distance BDC = h is the way of the wave.
|Illustration 2.4.1 wave propagation
|Because there is a stationary state, it is sufficient to look at the way of the wave from one source to the next source.
|The triangle of MCD in the picture 2.4.1 is rectangular in the point D and apply:
|Shift the equation to h:
|Since now all sizes are known, the wavelength can be determined:
|2.4.1 - Equation:
|In the equation is R
the radius of the Earth, n is the number
This results in the frequency equation for basic oscillations
|2.4.2 - Equation:
|n = 1,2,3,4,...
|The basic frequency is for n = 1:
|Illustration 2.4.2 basic oscillation
|This is also the oscillation of a bar with free ends, which length is equal to the diameter of the ball.
|200 sides, 23 of them in color
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