Chapter 7: Chaotic Stars

Astrophysics has not escaped chaotic behavior: for example, stars like our sun or variable stars exhibit oscillatory behavior that may eventually turn out to be chaotic. Since the end of the 19th century, Assyriologists have come to the cuneiform texts of the Babylonians, dating from two or three thousand years ago, report the discovery of stars whose luminosity is variable. This hypothesis is supported by observations of a star in the constellation of Cetus the Whale in the eastern part of Aquarius. This star could become visible and very brilliant or go out like a torch; it could appear dark, yellow, or very red. This description applies accurately to the star Mira Ceti. However, there is no reference to stellar variability in the catalog of Hipparcus (-130) or the Almagest of Ptolemy (≃ 138). This absence extends through the star catalogue Zij-i Sultani of Ulugh Begh — his name means the great ruler — (1394–1449) dating from 1437. It seems that the main reason for the absence of these phenomena in the scientific tracts is that dogma blinded observers. One of the foundational principles of Aristotle’s physics was that change was not possible in the supralunary heavenly world, home of the celestial bodies and constituted of the quintessence, the divine, imperishable and inalterable matter. In the sublunary world, where nature consists of the four other elements (water, earth, air, and fire), that changes could occur. In fact, it seems that medieval scientists were unaware of a number of celestial events, for example the supernova in the Crab nebula, that occurred on 4 July 1054, was recorded by the Chinese but for which there is no European record. The Chinese called “guest stars” those appearing temporarily.