On the precession of a viscous spheroid, and on the remote history of the earth.' Offprint from Philosophical Transactions, Part II, 1879. THE ORIGIN OF THE MOON

DARWIN, George H.

Verlag: Erscheinungsdatum: 1879

First edition, very rare offprint, of the first detailed account of Darwin s fission theory of the origin of the Moon, according to which the Moon was spun off the Earth in its early history due to centrifugal force. This theory was generally accepted until the latter part of the 20th century. Darwin calculated that the Earth would have had to have about a 2.5 hour day for the centrifugal force to have been sufficient for this to occur. "Before Kuiper revived the double planet thesis, George Darwin, son of the famous British naturalist, had in 1878 advanced an attractive alternative. Drawing on the pronounced tidal effects exerted between the earth and moon, Darwin speculated that the moon's mass had been ejected from a fluid and rapidly spinning protoearth when centrifugal force and solar tides, acting on matter in the earth's equatorial plane, exceeded the force of gravity. In time, the moon moved out to its present orbit and attained its coincident period of rotation and revolution as a result of tidal interactions between the two bodies. Darwin proposed that these tidal effects on the spherical shape of the earth have changed as the moon has moved farther away in its orbit. Darwin's proposed idea for the creation of the moon came to be known as the "fission theory" of lunar formation. This theory basically stated that the moon broke away from the earth due to its rapid rotation. From this he also calculated that it would have taken at least 56 million years for the moon to reach its current distance from the earth" (Giedd, Tidal Friction). Darwin argues "that tides raised by the Moon imply an Earth much closer to the Moon far in the past. Modeling Earth (and Moon) as a viscous liquid rather than a system dominated by oceans and basins, Darwin calculated that the two bodies merged about 50 million years ago, with the system rotating every five hours" (Crottis, The New Moon, 159). Darwin first suggested that the earth and moon once formed part of a single body in a two-page note in Nature (Vol. 18, 1878), but this is the first detailed account of the idea. Large 4to, pp. [ii], 447-538. Original printed wrappers (foxing to edges of wrappers, ends of spine slightly worn). Bestandsnummer des Verkäufers ABE-1475333110357

Bibliografische Details

Titel: On the precession of a viscous spheroid, and...
Erscheinungsdatum: 1879
Einband: Soft cover
Zustand: Very Good
Auflage: 1st Edition