Over at the Graham Hancock website, Hancock played host to Walter Cruttenden, an “amateur theoretical archaeo-astronomer” responsible for a documentary about ancient knowledge of the Precession of the Equinoxes, the apparent backward drift of the stars over time. Cruttenden calls the 2004 film, named The Great Year, “a PBS broadcast documentary,” though I can find no evidence that the independent production was ever part of PBS’s official schedule. Instead, it appears to have aired only once, on KOCE-TV, the Los Angeles PBS affiliate, and was never a PBS program. (KOCE lists it as originating locally, not via PBS.) On Hancock's website, Cruttenden presented an article on his speculation that history has alternating cycles of “light” and “dark” correlated to the astrological changes in the stars over time.
Cruttenden relies on the work of Giorgio de Santillana and Hertha von Dechend, the authors of Hamlet’s Mill, which claimed that an unknown ancient culture was able to (a) assign 360 degrees to the circle, (b) correctly determine the exact rate of precession—moving one degree of arc per 71.6 years, and (c) encode that information in myth by rounding the number to 72. This key number then became the foundation for various derivatives and multiples—432, 216, 36, etc.—that show up in key myths, relating to fractional or multiple degrees of arc.
According to Cruttenden, “the human being has an average life span that comprises only one-360th of the roughly 24,000-year precessional cycle.” That would be 67 years, today’s world average. However, lifespan varies wildly by time and location, and was but 30 years in the Paleolithic, and in modern countries today can approach 80 years. The precessional cycle is not 24,000 years, however, but 25,772 years, making one-360th 71.6 years, which is exactly equal to neither the world average lifespan or historical lifespan.
There is no evidence that anyone correctly determined the exact rate of precession before the modern period. Among the Greeks, Hipparchus and Ptolemy each made guesses at the rate but were off by about 25%. The Chinese, in the fourth century CE, made an estimate that was off by nearly 50%. The Indians came close, estimating the entire precessional cycle to within 1% of true, but this wasn’t until the twelfth century CE.
De Santillana and von Dechend over-interpreted evidence in light of modern understandings of precession. The fact is that the numbers they identified in myth have a much simpler explanation: they are all multiples of 2 and 3, the smallest numbers capable of generating complex multiples. We tend to think in tens because we use Arabic numerals, but this isn’t how ancient people thought. Early peoples, who did not use a decimal system, tended to use multiples of 2 and 3 because these were the easiest numbers for generating large multiples. We do not need to make recourse to the stars—much less astrological constellations not finalized in size, shape, or form until the Greeks—to explain them.
Consider this: If we already believe the ancients had the 360 degree circle, why do we need precession to “explain” “precessional numbers” since they are all fractions of or multiples of the 360 degree circle?
I suppose we could argue that the 360 degree circle itself derives from observations of the precessional cycle, but that forces us to ask how the ancients would have measured precession without some kind of math or measurement system to do so… and, of course, if they had that, then the precession isn’t the important concept, but rather the origins of this high level math before even the invention of the zero, which vanished without a trace. (Note: Any assumption of a preexisting math system runs into trouble with the supposed megalithic yard, another alternative staple whose measurements don’t jive with any measurement system derived from precession.)
But that is a question of math. Cruttenden’s other claims are historical, and just as wrong, even if he successfully seeded (as of this writing) his speculations into Wikipedia’s page on axial precession. Tomorrow we’re going to look at his claims about the rise and fall of civilization and whether it is tied to the stars. Spoiler alert: It's not.
I am an author and researcher focusing on pop culture, science, and history. Bylines: New Republic, Slate, etc. There's more about me in the About Jason tab.
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