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When sound is produced by the wind blowing past objects in its way, the usual mechanism is called vortex shedding and was studied by Von Karman in the late 1940s. In his model, sound waves are produced when the wind blowing past (for example) a wire toggles between blowing over the upper surface and the lower surface. This cyclic excitation gets coupled to ...


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Orbits are elliptical. An orbit that’s just a little bit elliptical, like the one perturbed by 1 m/s here, looks like bobbing up and down around the original circular orbit. And the period of that bobbing oscillation is equal to the orbital period: the motion goes down once and up once before returning to the same point and repeating.


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