## Plus Advent Calendar Door #6: Say, lovely woman...

Submitted by Marianne on December 6, 2014*The square root of half the number of a swarm of bees is gone to a shrub of jasmine; and so are eight-ninth of the whole swarm: a female is buzzing to one remaining male that is humming within a lotus flower in which he is confined, having been allured to it by its fragrance at night. Say, lovely woman, the number of bees.*

If only all maths questions could be that poetic! We haven't made this one up, rather it comes from the twelfth-century book *Lilavati* ("The beautiful"), written by the Indian mathematician Bhaskara. According to legend, Bhaskara had a beautiful daughter whose horoscope predicted she was to remain unmarried and childless. Not wanting to do without grandchildren, Bhaskara decided to defy destiny and built a water clock to determine an "auspicious moment" at which his daughter was to get married. But the girl couldn't resist a peak at the clock — a pearl from her dress fell into it and clogged up the hole, so the auspicious moment could never come. To console her, Bhaskara wrote her a maths book (lucky girl!) and named it after her: Lilavati. It's a beautiful book which would make a great present for anyone who likes maths and history.

We came across *Lilavati* while writing our book *Numericon*, and it wasn't the only historical marvel we found. Other highlights were John Napier's 1614 book *The description of the wonderful canon of logarithms* and Claude Shannon's revolutionary 1948 paper *A mathematical theory of communication*, which laid the foundations for computers as we know them. Happy reading!

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