- See also: Catastrophism and Neo-catastrophism
Coherent catastrophism is the hypothesis that the inner solar system, and consequently the Earth, has been subjected to catastrophes from passing comets. It is termed "coherent" because:
- "Cataclysms visit wide areas of the planet due to the coherent arrival of many impactors in a few days. It is entirely feasible that within those few days the earth could receive hundreds of blows like that of the Tunguska object."
Charles Frankel writes:
- "The periodic replenishment of the Earth-crossing population leads to the notion of coherent catastrophism. Coined by Australian astronomer Duncan Steel, the concept of coherent catastrophism arises from the fact that, episodically, a large comet might come rushing into the inner Solar System to get trapped there by the gravitational tug of the giant planets."
In his book, Perilous Planet Earth: Catastrophes and Catastrophism through the Ages, Prof. Trevor Palmer writes:
- "Nevertheless, whilst rejecting almost every aspect of Velikovsky's hypothesis, astronomers accept that a large cosmic body could pass close to the Earth and cause catastrophes. In particular, the Earth may be under threat from giant comets which, although small in comparison to planets, are very much bigger than the comets that are normally seen. That view has been developed mainly by British astronomers, including Victor Clube together with Bill Napier and Mark Bailey of the Armagh Observatory, Duncan Steel of Salford University (and formerly of Spaceguard Australia) and David Asher of Oxford University and the Communications Research Laboratory, Japan. On the basis of the likely range of diameters of cometery nuclei in the regions beyond Jupiter, and in particular in the Oort cloud, they have estimated that, several times every million years giant comets may become trapped in the inner Solar System. Even if there was on direct collision with the huge cometary nucleus, dust and boulders released from it could cause serious problems for life on Earth, especially if the nucleus started to break up under the gravitational influence of the Sun, which would be a distinct possibility. Such a scenario, involving devastation on Earth because of a cluster of small impacts over a short period of time, coupled with global cooling caused by the dusting of the upper atmosphere, all resulting from the break-up of a giant comet, has been termed coherent catastrophism. This distinguishes it from the concept of larger impacts occurring in isolation at longer intervals, which might be called stochastic catastrophism.
Bill McGuire notes:
- "Controversy has certainly not gone away, however, and argument continues amongst the scientific community, particularly about the frequency and regularity of impacts and - probably of most interest to the layman - about the effects of the next large impact on our civilization. The question of frequency is far from straightforward and serious disagreement exists between schools of thought that, on the one hand, support a constant flux of impactors and, on the other, advocate so-called impact clustering. Notwithstanding the very heavy bombardment of the Earth's early history, followers of impact uniformitarianism support a strike rate that is uniform and invariable. This is at variance with rival groups of scientists who are promoting an alternative theory of coherent catastrophism, within which the Earth, for one reason or another, periodically comes under attack from increased numbers of asteroids or comets."
Comparison with Velikovsky
Bruce Lerro writes:
- "Astronomers Clube and Napier distinguish their "neo-catastrophism" -- or "coherent catastrophism" -- from earlier catastrophist theories in several ways. Unlike Ignatius Donnelly and Immanuel Velikovsky, whose popular books in the later nineteenth and mid-twentieth centuries appeal to wide audiences, Clube and Napier do not suggest that comet or asteroid directly impacted the Earth during human history. Instead they argue that a huge comet (100 km) circulated through the solar system several thousand years ago, and the Earth periodically passed through its train of debris. Clube and Napier do not argue that the impact of this debris was always global in scope. Damage from impacts would have varied in magnitude depending on the size of the debris and where the objects hit (land or sea). Thus some of the resulting catastrophes would have been local, some regional, and some global."
Trevor Palmer describes Peter James and Nick Thorpe's view:
- "James and Thorpe describe Velikovsky as 'the great catastrophist' and explain how his writings produced impassioned responses, for as well as against his ideas. However, they then continue, 'During the 1980s, the Velikovskian bubble finally burst, or rather began to sag to the point of deflation'. In their view, the reason for that was the development of the theory of coherent catastrophism by Victor Clube and Bill Napier. This had no requirement for wandering planets as a means of explaining Bronze Age catastrophes and the myths derived from them, proposing instead the more plausible mechanism of the disintegration of a large comet in the vicinity of the Earth. James and Thorpe conclude, 'With the advent of this model, produced by professional astronomers, Velikovsky's extreme model became redundant'."
- ↑ "This might be termed the 'coherent catastrophism' school of thought, as opposed to the 'stochastic catastrophism' school." Steel, D. L (1991) 'Our asteroid-pelted planet', Nature 354, 265 - 267 (28 November 1991)
- ↑ Duncan Steel, details to follow
- ↑ Charles Frankel, The end of the dinosaurs: Chicxulub crater and mass extinctions, Published by Cambridge University Press, 1999, ISBN 0521474477, 223 pages (page 196)
- ↑ Trevor Palmer, Perilous planet earth: catastrophes and catastrophism through the ages, Published by Cambridge University Press, 2003, ISBN 0521819288, 522 pages. (page 206-207)
- ↑ Bill McGuire, "Global Catastrophes: A Very Short Introduction"(Paperback), Oxford University Press (January 2006), ISBN 0192804936 (page 98)
- ↑ Bruce Lerro, Power in Eden: The Emergence of Gender Hierarchies in the Ancient World, Published by Trafford Publishing, 2005, ISBN 1412021413, 418 pages (page 212)
- ↑ "Ancient Mysteries by Peter James & Nick Thorpe" (1999) reviewed by Trevor Palmer, SIS Chronology & Catastrophism Review 1999:2 (Feb 2000)
- Asher, D. J.; Clube, S. V. M.; Napier, W. M.; Steel, D. I., "Coherent catastrophism", Vistas in Astronomy, vol. 38, Issue 1, pp.1-27, 1994 (Abstract)
- Gerrit L. Verschuur, "Death Star or Coherent Catastrophism", Impact!: the threat of comets and asteroids, Published by Oxford University Press US, 1997, ISBN 0195119193, 256 pages. Page 128