Today’s Google doodle (for those not in the know, the Google homepage alters its header based on the date, and on dates of special nerdy significance, they theme them around relevant birthdays/anniversaries) is about Maria Gaetana Agnesi, a female mathematician. Agnesi was born on 16th May 1718, making today her 296th birthday. This means you have four years to prepare for her 300th birthday bash, which I hear is going to go off big style.
According to Wikipedia, Agnesi is credited with writing the first book discussing both differential and integral calculus, and was an honorary member of the faculty at the University of Bologna. She wrote books on algebra and analysis, and was the second woman ever to be granted a professorship at a university.
The curve depicted in the Google doodle is called the Witch of Agnesi, and traces the height of a point on the edge of a circle as it rolls along a line. It occurs in modelling of certain physical phenomena, as well as being related to probability functions, and was described by Agnesi in her 1748 book on summation, Istituzioni analitiche ad uso della gioventù italiana. The name ‘witch’ is believed to be a mistranslation of the Italian word ‘versiera’, a word for the rope used to bring a ship’s sail round, which is similar to ‘avversiera’, meaning ‘she-devil’.
More information
Maria Gaetana Agnesi Google Doodle
Maria Gaetana Agnesi, on Wikipedia
The Witch of Agnesi, on Wikipedia