Ancient Egyptians didn't know why one particular star seemed to blink. But they decided the phenomenon could bring luck.
The stars foretell?
The ancients knew there was something odd about the star Algol: it blinked, bright-dull-bright-dull, on a regular schedule.
Their astrophysics could not match today's high-tech scholarship - we know now that Algol is actually three stars, and that our view of the bright one is blocked by a dimmer one every 2.867 of our days. New research demonstrates, however, that human imagination back then was fully as vivid as today's.
Researchers at the University of Helsinki reported this week that a roll of papyrus from 1271BC, known as the Cairo Calendar, characterises each day as good, bad, or mixed - apparently on the basis that the days when Algol shone most brightly were considered the most promising.
In all the dubious constellation of arcane arts, fortunetelling is the one most aligned with the stars. There is no reason to think that the Cairo Calendar was history's first attempt to use the lights in the sky as a guide to terrestrial behaviour, and the disreputable but entertaining descendants of millennia of such efforts persist today, as horoscopes.
Astrological divination has not rewarded humankind, but science has. But while science keeps improving, we are still too often illogical in the way we use what we have learned about the world - and the heavens.