On September 19, Dr. Ron Perline, a professor of calculus and differential geometry at Drexel University, presented his topic, “Non-Euclidean Flashlights: A Tale of Two Blackboards”, for the Natural Science and Mathematics Colloquium.

Dr. Perline, who was the PH.D advisor of St. Mary’s professor of mathematics, Emek Köse, formatted his lecture to appeal to non-mathematics majors as well as aspiring mathematicians. Department Chair & Associate Professor of Mathematics, Dr. Susan Goldstine said that since “Dr. Perline gives excellent talks for a general audience…we agreed that he was a great candidate for the NS&M Colloquium series.” Dr. Perline insisted that one of the goals of his lecture was “to give a math speech that had no equations.” By the end of the lecture, Perline was glad to have met this goal. “This was the first time he gave a substantive mathematics talk with absolutely no equations in it, and he was quite pleased that he pulled it off.” added Dr. Goldstine.

Dr. Perline began his speech by explaining how he became interested in researching the parabola reflections of flashlights. He stated that his students had confronted him with a problem which made him ponder using calculus and geometry for the focus of parabola reflection. Dr. Perline carefully described how the path of light is reflected at “different speeds and distances” and how “you can predict the paths.” He further explained how his research correlated with building a flashlight. Using images of geometric shapes and graphs of light paths, Perline said “this is what you would do if you lived in a strange world and wanted to build a flashlight.”

Dr. Perline defined each mathematical term he used in order for the audience to follow him. The definitions were helpful in analyzing not only how light works in flashlights but also how cameras and mirrors can be attached to robots and used in reflecting light. In detailing such an advanced process and applying his mathematics to other fields, Dr. Perline still managed to avoid using technical terms and equations. “What’s important is the geometry that we had to guide us.” said Perline.

Students in attendance were enthusiastic about the lecture and what Perline had taught them. First Year student Alyson Thompson said “it was really cool. It was interesting to me because I want to be a math major.” Others expressed similar sentiments with two rounds of applause for the speaker. Dr. Perline was equally interested in the SMC community. “He specifically mentioned how impressed he was with St. Mary’s College of Maryland and all of the people he met here, students and faculty alike.” Said Dr. Goldstine.

Perline was pleased to find how eager students were to apply his lecture to other areas. “This shows that there’s so much to be invented.” declared Thompson. Goldstine stated, “Our goal with the NS&M Colloquia in math is always to have students see interesting math that they wouldn’t see in their classes…he also showed the audience ways in which he and his colleagues use math to build things in the real world.”