Happy Pi Day! Every year, March 14 reminds us to celebrate that brilliant mathematical symbol known as “pi” to the layman and 3.14159265358979323… (and trillions more!) to the mathematics buff. Pi (π)—the ratio of the circumference of a circle to its diameter—is a somewhat magical number because it is the same for all circles of any size. Both its universal applicability and its infinitesimal transcendence are intriguing. Pi continues infinitely without repetition or pattern and has captured the minds of many since Ancient Babylonia. While the accurate estimation of this never-ending number has been credited to a man (i.e. Archimedes of Syracuse, 287-212 B.C.E.), women mathematicians have been instrumental in the field as well. Here are a few women in the history of mathematics to celebrate.

## Hypatia of Alexandria (370?-415 C.E.)

One of the earliest known women mathematicians is Hypatia of Alexandria (370?-415 C.E.). Raised by her father, Theon, who was considered amongst the most educated in Egypt, she was a talented mathematician, philosopher, astronomer, and scientist. Although many disapproved of educated women during her time, Hypatia’s work was instrumental in developing the modern concepts of hyperbolas, parabolas, and ellipses. In fact, her research was later expanded upon by René Descartes, Isaac Newton, and Gottfried Wilhelm Leibniz. Hypatia’s extraordinary accomplishments demonstrate the clear importance of early women mathematicians.

## Sophie Germain (1776-1831)

Sophie Germain (April 1, 1776 - June 27, 1831) was a self-taught French mathematician. Although her parents tried to discourage her from learning (it was believed that mathematics was an inappropriate trade for women at the time), Germain would sneak into her father's library to read the works of great mathematicians going so far as to wrap herself in quilts and use candles she had hidden in order to study throughout the night. After learning what she could on her own, she decided to advance her knowledge by corresponding with prominent mathematicians Adrien-Marie Legendre and Carl Friedrich Gauss under the male pseudonym “M. LeBlanc.” Her decision to identify as a man to prove her worth in the male-dominated field of mathematics was fruitful. Her work in number theory, the theory of elasticity, and in developing innovative approaches to prove Fermat's Last Theorem are highly significant contributions to mathematics. Fighting against the social prejudices of the times, she rose to the top becoming an equal collaborator with male mathematicians toward the end of her career.

## Charlotte Angas Scott (1858-1931)

Charlotte Angas Scott (June 8, 1858 - November 10, 1931) was another women pioneer as the first woman in England to receive a doctorate in mathematics. Going against the social scripts of the time and with her family’s support, she sought education from a young age and this sparked an early interest in mathematics. In 1880, Scott ranked eighth in the highly prestigious Cambridge Mathematical Tripos Exam but because she was a woman, she could not attend the award ceremony. After earning degrees from the University of London, she traveled to the United States and became a founding faculty member of the Department of Mathematics at Bryn Mawr College where she mentored other women to pursue careers in mathematics. Scott’s work with algebraic curves and plane analytical geometry played a significant role in the modern development of abstract mathematical proofs. Her 1899 article “Proof of Noether's Fundamental Theorem” is widely recognized as highly influential in the field of mathematics.

## NASA’s Human Computers

The 1950s ushered in a new wave of women mathematicians, although many have been “hidden” from dominant discourse. Take, for example, a group of African American women mathematicians known as NASA’s “human computers” due to their highly skilled abilities to perform the complex calculations that helped humans into outer space. These women include Mary Jackson, Katherine Johnson, and Dorothy Vaughan who have all been celebrated in the Oscar-winning film, *Hidden Figures*, as well as Miriam Daniel Mann, Kathryn Peddrew, Christine Darden, and Annie Easley who are featured in the book *Hidden Human Computers: The Black Women of NASA*. Another woman who worked for NASA to help get man to the moon was space engineer Mary Golda Ross, who was a member of the Cherokee Nation and the first female Native American rocket scientist. Facing both gender and racial discrimination, the accomplishments of these women should not be understated. Without their mathematical brilliance, space travel would not have been possible. In fact, Katherine Johnson is being immortalized in LEGO format as part of a “Women in NASA” playset that will also feature the first American woman in space Sally Ride, the first female NASA executive (and “Mother of the Hubble” telescope) Nancy Grace Roman, the first African-American woman in space Mae Jemison, and Apollo 11 software engineer Margaret Hamilton.

Pi is perhaps the most recognized and most intriguing mathematical construct in the world. From Babylonia to Egypt to China to Baghdad, ancient mathematicians worked tirelessly to compute pi to determine the area of a circle. Women mathematicians, however, have often been overlooked. But gender does not define our search for knowledge. In fact, some scholars claim that humans search for patterns, prove theorems, and identify mathematical complexities in order to give meaning to the world and ourselves. Both men and women mathematicians contribute to this process and their contributions should be celebrated with equal enthusiasm. After all, the pursuit for mathematical knowledge is never-ending, much like the numbers in π.

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