The Origin and Evolution of the Solar System begins by describing historical, i.e. pre-1950, theories and illustrating why they became unacceptable. The main part then critically examines five extant theories, including the current paradigm, the Solar Nebula Theory, to determine how well they fit with accepted scientific principles and observations.
A graduate-level tex outlining a succession of theories on the origin and evolution of the solar system, providing details gathered by modern astronomers that may be helpful in producing a plausible theory and giving new constraints that must be satisfied by a theory. Includes black and white and color illustrations.
This book describes the four major theories that have been under development during the last two or three decades: the Proto-planet Theory, the Capture Theory, the Modern Laplacian Theory and the Solar Nebula theory, and gives the main theoretical basis for each of them. Also discussed, but not so fully, is the Accretion Theory, an older model of solar-system formation with some positive features. These theories are examined in detail to determine the extent to which they provide a plausible mechanism for the origin of the solar system and their strengths and weaknesses are analysed. The only theory to essay a complete picture of the origin and evolution of the solar system is the Capture Theory developed by the author and colleagues since the early 1960s. This explains the basic structure of the solar system in terms of well-understood mechanisms that have a finite probability of having occurred. The way in which planets form, and the way that their orbits originate and evolve according to the Capture Theory, suggests the occurrence of a major catastrophic event in the early solar system. This event was a direct collision between two early planets, in terms of which virtually all other features of the solar system, many apparently disparate, can be explained. As new knowledge about the solar system has emerged so it has lent further support to this hypothesis.
There is a tendency in areas of science like cosmogony for a ‘democratic principle’ to operate whereby the theory that has the greatest effort devoted to it becomes accepted, without question and examination, by many people working in scientific areas peripheral to the subject. These individuals, highly respected in their own fields, swell the numbers of the apparently-expert adherents and, by a positive feedback mechanism, they enhance the credibility of the current paradigm—which is the Solar Nebula Theory in this case. Science writers and those producing radio and television programmes, accepting the verdict of the majority, produce verbal and visual descriptions of an evolving nebula that, if they were to illustrate any scientific principle at all, would be illustrating the invalid
principle of the conservation of angular velocity
. In scientific television programmes material is seen spiralling inwards to join a central condensation having jettisoned its angular momentum in some mysterious fashion on the way in. Computer graphics are not constrained by the petty requirements of science!
The ‘democratic principle’ is not necessarily a sound way to determine the plausibility of a scientific theory and there are many examples in the history of science that tell us so. The geocentric theory of the solar system, the phlogiston theory of burning and the concept of chemical alchemy were all ideas that persisted for long periods with the overwhelming support of the scientific community of the time.