Scientific Papers: Tidal friction and cosmogony. 1908University Press, 1908 - 516 Seiten |
Andere Ausgaben - Alle anzeigen
Häufige Begriffe und Wortgruppen
angular velocity approximation axis bodily tides coefficient consider cos² curve density differential diminishes disturbing function diurnal earth and moon eccentricity ecliptic effects elastic energy equal equations expression g₁ harmonic Hence homogeneous hypothesis inclination increase inequalities inertia integration invariable plane K₁ K₂ L₁ lunar orbit lunar precession m₁ m₂ mass maximum mean distance moment of inertia moon's nodes numbers nutation obliquity orbital momentum orbital motion paper on Precession period planet planetary potential present problem Q²)² revolve rigid satellite satellite's secular changes semi-diurnal sidereal sin 2g sin 4f sin² sinj small viscosity solar tidal friction solid harmonic solution sphere spheroid stress-difference stresses suppose surface theory tidal reaction tide-generating tide-raiser values viscosity W₁ zero αξ κι
Beliebte Passagen
Seite 127 - The tides must have been very much more frequent and larger, and accordingly the rate of oceanic denudation much accelerated. The more rapid...
Seite 514 - It is difficult to avoid the conclusion that the whole of the solid portion of the earth is in a sensible state of stress. I would not however lay very much emphasis on this point, because we are in such complete ignorance as to the manner in which the equilibrium of the solid part of the earth is maintained. From this discussion it appears that if the earth be solid throughout, then at a thousand miles from the surface the material must be as strong as granite. If it be fluid or gaseous inside,...
Seite 501 - Hence the interior of the earth must be in a state of stress, and as the land does not sink in, nor the sea-bed rise up, the materials of which the earth is made must be strong enough to bear this stress. We are thus led to inquire how the stresses are distributed in the earth's mass, and what are their magnitudes. These points cannot be discussed without an hypothesis as to the interior constitution of the earth. In this paper I have solved a problem of the kind indicated for the case of a homogeneous...
Seite 189 - In the case of the earth the wrinkles would run north and south at the equator, and would bear away to the eastward in northerly and southerly latitudes ; so that at the north pole the trend would be north-east, and at the south pole north-west. Also the intensity of the wrinkling force varies as the square of the cosine of the latitude, and is thus greatest at the equator and zero at the poles. Any wrinkle, when once formed, would have a tendency to turn slightly, so as to become more nearly east...
Seite 506 - Numerical calculation shows that if we take a series of mountains, whose crests are 4000 meters, or about 13,000 feet above the intermediate valley-bottoms, formed of rock of specific gravity 2'8, then the maximum stress-difference is 2'6 tons per square inch (about the tenacity of cast tin) ; also if the mountain chains are 314 miles apart, the maximum stress-difference is reached at 50 miles below the mean surface. It...
Seite 458 - These investigations afford no ground for the rejection of the nebular hypothesis; but while they present evidences in favor of the main outlines of that theory, they introduce modifications of considerable importance. Tidal friction- is a cause of change of which Laplace's theory took no account; and although the activity of that cause...
Seite 506 - It was formerly supposed that the ellipticity of the planet was even greater than ^j, and even if the latest telescopic evidence had not been adverse to such a conclusion, we should feel bound to regard such supposed ellipticity with the greatest suspicion, in the face of the result just stated. The state of internal stress of an elastic sphere under tide-generating forces is identical with that caused by ellipticity of figure.t Hence the investigation of § 5 gives the distribution of stress-difference...
Seite 506 - The stresses produced by harmonic inequalities of high orders are next considered. This is in effect the case of a series of parallel mountains and valleys, corrugating a mean level surface with an infinite series of parallel ridges and furrows. It is found that the stress-difference depends only on the depth below the mean surface, and is independent of the position of the point considered with regard to ridge and furrow. Numerical calculation shows that if we take a series of mountains, whose crests...
Seite 370 - Thus changes of the kind here discussed must be going on, and must have gone on in the past. And for this history of the earth and moon to be true throughout it is only necessary to postulate a sufficient lapse of time, and that there is not enough matter diffused through space materially to resist the motions of the moon and earth in perhaps several hundred million years.