The motion of a satellite about its planet is one of revolution or rotation. When the satellite moves in an ellipse of any given degree of eccentricity, there is a certain amount of rotation in the system, technically called rotational momentum, and it is always the same at every part of the orbit. (Moment of momentum or rotational momentum is measured by the momentum of the satellite multiplied by the perpendicular from the planet on to the direction of the path of the satellite at any instant.)英文原著 · 《Darwin and Modern Science》
The attraction of gravity alone tends to make a mass of liquid assume the shape of a sphere, and the effects of rotation, summarised under the name of centrifugal force, are such that the liquid seeks to spread itself outwards from the axis of rotation. It is a singular fact that it is unnecessary to take any account of the size of the mass of liquid under consideration, because the shape assumed is exactly the same whether the mass be small or large, and this renders the statement of results much easier than would otherwise be the case.英文原著 · 《Darwin and Modern Science》
Copernicus shows clearly how the observed phenomena could be accounted for just as completely by a rotation of the earth as by a rotation of the heavens. He alludes to the fact that, to those on board a vessel which is moving through smooth water, the vessel itself appears to be at rest, while the objects on shore seem to be moving past. If, therefore, the earth were rotating uniformly, we dwellers upon the earth, oblivious of our own movement, would wrongly attribute to the stars the displacement which was actually the consequence of our own motion.英文原著 · 《Great Astronomers》
I shall come later to the classification of all possible forms of ideal liquid stars, which have the same amount of rotational momentum, and the classification will then be made according to their densities, but the idea of orderly arrangement in a "family" is just the same.英文原著 · 《Darwin and Modern Science》
In each family there is one single member which is indistinguishable from a member of the other family; it is called by Poincare a form of bifurcation. It is this conception of a form of bifurcation which forms the important consideration in problems dealing with the forms of liquid or gaseous bodies in rotation.英文原著 · 《Darwin and Modern Science》
This new series of figures, generally named after the great mathematician Jacobi, is at first only just stable, but as the density increases the stability increases, reaches a maximum and then declines. As this goes on the equator of these Jacobian figures becomes more and more elliptic, so that the shape is considerably elongated in a direction at right angles to the axis of rotation.英文原著 · 《Darwin and Modern Science》
Well, I'd have to think about it - Crop rotation, livestock versus cereals,美剧 · 《Downton Abbey》
By the way, I've been looking into crop rotation and grain sales - And not every father hears that from his daughter.美剧 · 《Downton Abbey》
We pushed for immediate rotation, - but the Israelis have-- - No, of course.美剧 · 《House of Cards》
Isn't the coriolis effect something about the earth's rotation?美剧 · 《Lie to me》
Then, using vector analysis, you use rotational symmetry, and you get this next set. Then, using vector analysis, you use rotational symmetry, and you get this next set.演讲 · 《Beauty, truth and ... physics ~ Murray Gell-Mann》
So even with the slowing of the rotation of the earth and so on, So even with the slowing of the rotation of the earth and so on,演讲 · 《The Long Now ~ Stewart Brand》