Hopping back from deceptively un-cerebral children's books about Star Wars rip-offs to Netflix's "Cerebral TV" stream (who names these things?) . . .

That led us last night to Michael Wood: In Search of Myths & Legends, which had an episode on the historical King Arthur and the cultural and political forces that caused his legends to elaborate and diversify, adapting themselves to every new environment they entered.  He started out as a Welsh rebel against the Saxons, but by the time of the Tudors, Henry the 8th (Welsh) was having his own face painted onto Arthur's body to legitimize his own rule.  The meaning of that portion of the legend had completely reversed itself, like a chromosomal inversion.  The tragic adulteries and such right next to it on that cultural information package were unaffected by that change.

My son ran off to play with the neighborhood gang instead of watching it, but it reminded me of James Blaylock's novel, The Paper Grail.  Not my favorite of his books, but has some clever ideas embedded here and there.  He's always funnier than a lot of SF, which I do appreciate.

That led to Discovery Atlas 4D (voiced by Campbell Scott), a series on how geography influences biology and human culture (upping the evolutionary ante on last year's favorite, Mutant Planet).  The first episode was about. . . The Great Rift Valley!  OK, you're right -- that's really more of a tearing and a bubbling than a folding, so it's a reach, origamically speaking.  But it was quite evolution-focused, describing once again the crazy diversity of cichlid fish in the huge lakes that fill parts of the Rift, and the evolution of humankind from Ardipithecus on down.  The new twist was that they also included lots of cultural tidbits.  Things about the salt miners of the Daka Depression, whose habit of drinking fluoride in large amounts (much higher levels than we do here) softens their teeth, making it easy to chisel them into points.  Or about the sardine fishing practices of the people around Lake Tanganyika.

Documentaries like this one can tell fairly complicated stories, like the cause-and-effect chain that leads from volcanoes to thin, rich soil to seas of grass to huge herds of cud-burping ruminants like wildebeests to herding cultures like the Masai, who are smart enough to use thorny acacia branches to keep their cattle safe from lions and hyenas, but who had no defense against Western diseases.  These stories are told straightforwardly, with no doubt, no ambiguity.  This is narrative, and it's compelling.  But it's misleading.  Science does not progress so smoothly, so surely.  It goes more like the British railroad described in this episode, one mistake after another, in a "Lunatic Line," or branching out like the Arthur myths into a tangled mess of disagreements.  It usually gets sorted out eventually, but for the outsider, who just has a snapshot of that process,  it must be frustrating.  Thus the market-driven impulse to simplify things.