Kant-Laplace theory
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Kant-Laplace theory names two related, but independently developed cosmological hypotheses about the development of the universe and the formation of our planetary system .
The two theories
A hypothesis similar to the Kant-Laplace theory can already be demonstrated with Emanuel Swedenborg .
Immanuel Kant developed his cosmogony in the text General Natural History and Theory of Heaven ( 1755 ). In his theory, Kant assumes a basic state in which matter in the universe was scattered in a primordial fog and then moved into today's equilibrium through attraction and repulsion . Kant stated:
"After I put the world into the simplest chaos, I have used no other forces than attraction and repulsion to develop the great order of nature, two forces which are both equally certain, equally simple and equally original and general."
However, this work by Kant received little attention and was only rediscovered 100 years later by François Arago . Around 40 years after Kant, the French mathematician and astronomer Pierre-Simon Laplace developed his nebular hypothesis independently of Kant , which appeared in the last volume of his five-volume work Exposition du systeme du monde (Representation of the world system) in 1796 . Laplace concentrated on the formation of the planets of the solar system and proceeded from the expansion of the heated atmosphere of an already existing heated sun . As a solar nebula, this assumed a lens-shaped shape for analogous reasons. In the course of the cooling and corresponding compression of the gas envelope, the centrifugal force over time predominated in its outermost area and several gas rings detached one after the other, which further condensed into the planets.
Arthur Schopenhauer and others later saw the common points of Kant's and Laplace's cosmogonies and spoke of them in a simplified way as of a unified theory.
meaning
The Kant-Laplace theory is assigned great importance in terms of philosophy and the history of science , as it tried to explain the formation of the planetary system without the aid of a supernatural force of order. Isaac Newton still thought such an explanation was impossible and thus accepted God as an indispensable part of every cosmogony . Kant and Laplace can therefore be regarded as important masterminds of today's theories of cosmogony.
Objections and Modifications
The Kant-Laplace theory was recognized for about 100 years. Thomas See modified it in detail in 1893 to explain the origin of the many double and multiple star systems discovered from a primordial nebula and rotating equilibrium figures.
In the late 19th century, however, some serious weaknesses in the Kant-Laplace theory were found. James Clerk Maxwell argued that if the matter of the known planets had once been distributed in the form of disks around the sun, the forces of differential rotation would have prevented the condensation of individual planets in the outer area. Another objection was that the sun has less angular momentum than it should have according to the theory.
For several decades now, most astronomers preferred the near-collision theory : The planets were formed when another star approached the sun. The mutual tidal forces tore large amounts of matter from the sun and the other star, which then condensed into planets.
During the 1940s, the Kant-Laplace theory was slightly modified again. The mass of the original protoplanets was estimated to be greater and the lack of angular momentum was explained by the effect of magnetic forces . In this modified form, the theory was generally accepted again around 1960 and is still accepted today.
literature
- Immanuel Kant: General Natural History and Theory of Heaven . German, Frankfurt / M. 2005, ISBN 3-8171-3415-0
- Pierre S. Laplace: Celestial Mechanics . Chelsea Publications, Bronx, NY 1976, ISBN 0-8284-0214-0 (5 vols.)
- "Representation of the world system Volume 1, books 1–3: On the apparent movement of the heavenly bodies / On the true movement of the heavenly bodies / On the laws of movement", translated by Manfred Jacobi, Franz Kerschbaum, Ostwalds Klassiker series, Vol. 301, Harri German, 2008, ISBN 978-3-8171-3301-7
- "Representation of the world system Volume 2, Books 4–5: From the theory of general gravity / Outline of the history of astronomy", translated by Manfred Jacobi, Franz Kerschbaum, Ostwalds Klassiker series, Vol. 302, Harri Deutsch, 2008, ISBN 978- 3-8171-3302-4
- Joachim Ritter (Hrsg.): Historical dictionary of philosophy . Schwabe Verlag, Basel 1998, ISBN 3-7965-0115-X (12 vols.)
Individual evidence
- ↑ Friedemann Stengel : Enlightenment to Heaven. Emanuel Swedenborg in the context of theology and philosophy of the 18th century , Tübingen 2011, p. 110.
- ↑ L.Weinek Atlas der Himmelskunde 1898, p.147