Something of wonder

A wave traveling between two parabolic antennas

This simulation was suggested by several viewers, following the simpler version. It shows the evolution of a circular wave, emitted from the focus of a parabolic antenna. The part of the wave reflected on the antenna is transformed into a planar wave, which travels to the facing parabola with almost no loss of energy. The second parabola transforms the wave back into part of a circular wave, which is then concentrated in its focal point. In this way, signals can be transmitted over much longer distances than shown in this simulation, with little loss of power. Note that non-planar waves are also concentrated near a point, which is however different from the parabolas' focal point.

The colors indicate the energy of the wave: blue means low energy, red means high energy. The boundary conditions in the simulation are absorbing, but do not work perfectly, which is why you see some reflections from the sides of the outer rectangle. Nils Berglund

Had to show another

How a parabolic antenna works

This new episode of #shorts shows the basic principle of a parabolic antenna. A circular wave is emitted from the parabola's focus, and becomes a planar wave upon reflection on the parabola. Therefore, this part of the wave does hardly disperse when traveling to the right, allowing it to cover long distances with very little loss of energy. By the same principle, a planar wave is reflected towards the focus, concentrating its energy in one point. This can be observed on the part of the wave reflected on the right boundary, due to imperfect absorbing boundary conditions used there. The colors indicate the energy of the wave: blue means low energy, red means high energy. 

Music:  Prelude No. 6 by Chris Zabriskie
is licensed under a Creative Commons Attribution 4.0 licence.
https://creativecommons.org/licenses/...

Source: http://chriszabriskie.com/preludes/

Artist: http://chriszabriskie.com/

Something of wonder indeed