Egyptian Stars under Paris Skies
by Jed Z. Buchwald
One evening in early July of 1822 a group gathered for dinner at the home of the leading figure in French science, the Marquis de Laplace, outside Paris. The guests included five of the most distinguished physicists and chemists of the day: Jean-Baptiste Biot, famed for his experimental
work in optics and electricity; François Arago, rapidly becoming an influential administrator of science, the editor of an important journal, and
himself a reasonably accomplished experimenter in optics; Joseph Fourier, who had developed the series representation now termed Fourier analysis
and whose controversial theory of thermal diffusion had already been widely discussed; the influential chemist Claude Berthollet; and John
Dalton, the English protagonist of the atom. The previous several years had seen remarkable developments in French science, including fundamental discoveries in electricity, magnetism, heat, and optics. Most of the dinner guests had participated in these events, often on opposing sides. Biot and Arago were scarcely on speaking terms, Fourier’s mathematics and his heat theory were not well thought of by Biot and Laplace, and Berthollet had little sympathy for chemical atomism. Yet
the evening’s conversation had nothing to do with physics, chemistry, or mathematics. Instead, the guests discussed the arrival in Paris of a zodiac
from a ceiling in the Egyptian temple of Dendera, bought by King Louis XVIII for an immense sum. This was not the first time that Dendera had
ignited discussion. On his return from Napoleon’s colonial expedition to Egypt in 1799, the artist Vivant Denon had made available his sketch of
what certainly looked like a zodiac. In short order articles appeared concerning the age of what many took to be a relic of antique Egyptian skies. For if the zodiac were literally an image of the heavens,
then astronomy might be used to establish its date of production. Since hieroglyphs were to remain unreadable for another two decades, Dendera
offered the tantalizing possibility of establishing Egyptian chronology on the basis of something beyond the few Greek and Latin texts that had
been carefully studied by Renaissance humanists. Though some of these texts contained words that could be interpreted astronomically, a great deal
of speculation and argument was needed. Several French scientists of the day were convinced that the Dendera ceiling was much more reliable than
words. Words, filtered through the sieves of human culture and history, were thought by an early cadré of French savants known as Idéologues—
who were concerned with social systems—to be imperfect reflections of external reality. Images seemed to be different, more trustworthy, because
they were considered to connect directly to original sensations stimulated by the natural world. Here lay the seeds of a growing mismatch
between historical and scientific sensibilities, at least in 19th-century France, and likely elsewhere as well.
The French astronomer and head of the Paris Bureau of Longitude, Jérome de Lalande, heard about Denon’s as yet unpublished sketch in 1800.
Reports that he read seemed to indicate that the circular zodiac was at least 4,000 years old. Furthermore, a second star ceiling discovered at Esneh seemed to be older still, dating perhaps to 7,000 years before the present era. If Esneh were that old, Lalande concluded, then a claim made by one..
Continued with vital illustration at:
http://calteches.library.caltech.edu/40 ... yptian.pdf
