windyy
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# How many windmills can we build without stopping the earth's rotation?

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Your question implies that there is friction with the earth's atmosphere and space. There is no friction between the atmosphere and space, so theoretically you could put a windmill on every square meter of the surface (or whatever size the windmill takes).

There is some friction with the atmosphere and the earth (ground surface or sea), but while the wind may be blowing east where you live on a given day, it would be blowing west in another area, north in another area, etc. etc., so the effects on the earth's rotation are random, therefore there is little effect.

Windmills, everywhere, would not effect the rotation of the earth.

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Of course there is no clear answer to this question. However, using wind power WILL indeed slow down the earth's rotation, even if only veeery slowly. By the way it does already do so spontaneously, about 73 microseconds per day.

Due to the Coriolis force, the wind blows from the West in most places on earth. If no work is extracted from the wind, it will transmit some of its kinetic energy to some mountainsides or trees and thereby give the earth a little push in the direction of its normal rotation. If we make the wind do work, less of its kinetic energy will be available for helping the earth's rotation.

Eleventy-three.

Is this like one of them there questions like, what's the sound of one hand clapping? Windmills dont stop the earths rotation, in fact they may be just as likely to speed it up.