by Frances Gilham
In the early 1800s, it was a common belief that women, having smaller brains than men, would endanger their health if they did too much thinking. Yet for most of that century, the textbook used for teaching higher astronomy at Cambridge University, where women were not allowed to enter, was written by a woman.
That woman was Mary Somerville, who, along with eighteenth century physicist Emilie Du Chatelet, is the subject of a book written by Robin Arianrhod that explores the extraordinary influence of these two women on the popularisation of Isaac Newton’s theory of gravity.
Entitled Seduced by Logic, the novel explores the lives of the two women and documents how their achievements changed humanity’s understanding of its place in the universe.
Speaking at the Sydney Writers Festival, Ms Arianrhod set the scene for the story of these women by explaining the cultural and philosophical significance of Newton’s publication of his theory of gravity in the late 1600s.
“It is astonishing to think that once this was contentious. But it was,” she said.
Because no-one knew what was behind this mysterious force of gravity, which could act invisibly on objects great distances apart, the great minds of that period found the concept impossible to comprehend. The prevailing belief at the time was based on the theories of the French philosopher Descartes.
“They thought there must be some sort of cosmic ether, swirling vortices that pushed the planets around the sun,” Ms Arianrhod said.
The idea of gravity as a phenomenon intrinsic to all types of matter was challenging religiously and philosophically as much as scientifically.
“The philosophers thought, is this mysterious force a substitute for God? Is everything materialist and if so, what do we need God for?” Ms Arianrhod said.
Emilie Du Chatelet was born into the aristocracy in 1706, almost 20 years after Newton’s book Principia Mathematica was published, in which he outlined his theory of gravity. Fascinated by mathematics and Newton, and undeterred by his critics, she set up an Academy of Free Thought where she and her peers replicated Newton’s experiments with light, and wrote philosophical essays.
Mary Somerville, in contrast, was born a poor Scottish peasant. Her only training was “a year in a posture device learning to copy the dictionary”, Ms Arianrhod said. “Her aunt had a telescope and used it to spy on her neighbours – that was as scientific as it got. But she said if women weren’t meant to think and read, then why did God give us brains?”
Ms Somerville went on to have an acclaimed career in mathematics and theoretical physics, and became an expert in Newton’s theories.
Ms Arianrhod, herself a mathematician based at the University of Sydney, said her career was strongly inspired by these great women. Her own experience shows that things are changing – but slowly.
“When I was studying at school, it was still not seen as the done thing for girls to do maths and science. I went to a guidance counsellor, who said your tests are good and you could probably apply to study at Cambridge but why would you bother? You’ll get married,” she said.
Ms Arianhod is fascinated by the language and the philosophy of mathematics, in much the same way as Emile Du Chatelet and Mary Somerville were 200 years ago.
“How can it be that mathematics, a concept of the human mind, can explain the whole natural world?” she said.