Science in history: understanding Isaac Newton

From the history of autism to ballooning in the Enlightenment, the University of Toronto's new series of free talks at the Toronto Public Library offers the public a chance to delve into the history of science.

And on Wednesday, October 16, Associate Professor Brian Baigrie, of U of T's Institute for the History & Philosophy of Science and Technology (ISPST)  heads to the Danforth/Coxwell branch of the Library to share the story of English mathematician and physicist Sir Isaac Newton.

The event is part of the University's science engagement program organized by Professor Ray Jayawardhana, Canada Research Chair in Observational Astrophysics and the U of T president’s senior advisor on science engagement, in partnership with the Toronto Public Library and Professor Craig Fraser of the IHPST.

U of T News spoke with Baigrie about the importance of science engagement, the history of science, and what Toronto Public Library audiences can expect from his talk.

Tell us a bit about your work.
My work is interdisciplinary in character. It looks at the natural sciences for insights into a cluster of questions concerning the nature of evidence and evidential reasoning. When I started out, my postdoctoral studies explored the evidential relationship between Kepler's laws of planetary motion and Isaac Newton's law of universal gravitation. I was never a Newton scholar in the sense that my work was focused on the intellectual and cultural factors that played a part in opening Newton's mind to the universality of gravitational attraction. My interest, rather, has always been in the various pieces of information that Newton puts together and the way that these are parlayed by Newton into a persuasive argument for the universality of gravitation. These days, my focus is on the life sciences, especially biomedicine, but my focus is still on issues related to evidence.

What drew you to this field – and to U of T?
My graduate training was in philosophy of science, specializing in methodology. When the opportunity presented itself to move to the University of Toronto and to IHPST, I jumped at the chance to work in an interdisciplinary environment and a world-class University.

Why should students today study this area?
Newton is one of the few scientists to have an historical period (The Age of Newton) named after him and, given his stature, one would suppose that there is little left to be done. Each generation, however, adds their own perspective to our historical narratives and the work and achievements of this and every other scientist is re-interpreted in light of new interests and sentiments. 

What can people expect to hear on Wednesday?
Newton was a great unifier: He laid the foundations for the differential and integral calculus. He produced simple analytical methods that unified many different techniques that had been developed to solve problems that were thought to be unrelated. In physics, he showed that the universality of gravitational attraction unified fields of terrestrial mechanics and celestial mechanics -- fields that were thought be be distinct.

Indeed, his treatment of such phenomena was the eccentric orbits of comets, the tides and their variations, the precession of the Earth's axis, and the motion of the Moon as perturbed by the Sun's gravity arguably created the science of physics and the form or characteristic style of explanation that we find in Newton's seminal treatise— The Principia (1687) -- still holds sway in physics today.

Finally, Newton made important contributions to optics and constructed the first telescope that used a curved mirror to prevent light from being broken up into unwanted colours.

Any one of these contributions would have secured Newton a prominent place in the annals of science. Taken together, it is clear why his achievements cast such an immense shadow across the physical sciences. It is also clear that we do Newton an injustice if we try to summarize his work in an hour or so. I think that a more rewarding approach is to focus on one of these achievements and see if we can shed some light on why Newton Principia has long been regarded as the most important work in the history of science. On Tuesday, the audience will be given a non-technical overview of Newton's argument. I will then consider some of the reasons why this argument is still seen as a great moment in science.

Why is science engagement important?
Science is one of our principal areas of human endeavour with applications that have shaped our world and our lives. So important is science in every aspect of our daily living that I think it is imprudent for us not to be as conversant with science as we possibly can be.