## 2013 Chesley Lecture: Wild Beauty: Postcards from Mathematical Worlds

The 2013 Chesley Lecture, entitled *Wild Beauty: Postcards from Mathematical Worlds*, was given by Professor James Propp, of the University of Massachusetts Lowell, on November 11, 2013. You can see the poster for the talk at the right, the abstract below, and a video of the talk at the bottom of the page.

**Abstract**

Mathematics is about the real properties of imaginary worlds. Applied mathematicians study idealized versions of the physical world; pure mathematicians have license to stray much farther from the realm of the actual. Faced with this freedom, pure mathematicians like myself ask: Out of all the possible worlds that can be conjured, which ones will I study?

Most often we study what strikes us as beautiful. Unfortunately, what's beautiful to a mathematician can be incomprehensible to a non-mathematician. Fortunately, there are exceptions to this: images like the Mandelbrot set that speak to a basic human urge to find a balance between order and wildness.

I'll share some images from the field of random spatial processes that I hope will offer pleasure. I'll also discuss some of the mathematical ideas (involving probability, geometry, physics, and computer science) that underlie them. Finally, I'll touch upon the role I have played in the lives of some of these ideas, and the role they have played in mine.

**Brief Biography of James Propp**

Professor James Propp is a researcher and teacher who did his doctoral work in mathematics at U.C. Berkeley, and has taught at Berkeley, Brandeis, Harvard, M.I.T., the University of Massachusetts Lowell, and the University of Wisconsin Madison. He is known for creating collaborative research groups that bring together undergraduates, graduate students, and faculty. His research is at the boundary between combinatorics, probability theory, and dynamical systems theory.

Propp's research is highly visual in nature, and computer-generated imagery often plays a significant role in his projects. He is both fascinated and repelled by randomness, and the tension between determinacy and randomness plays itself out in his work in numerous ways. In addition to discovering new mathematics and teaching "old" mathematics, Propp enjoys creating mathematical puzzles, one of which (his Self-Referential Aptitude Test) has been extensively circulated over the internet over the past two decades.