Math Encounters

Math Encounters is MoMath’s popular free public presentation series celebrating the spectacular world of mathematics, produced with support from the Simons Foundation. For further information, call the National Museum of Mathematics at 212-542-0566 or e-mail

Next presentation:

“Tales of Impossibility: The Problems of Antiquity”
with David Richeson — November 6 at 4:00 pm

“Tales of Impossibility: The Problems of Antiquity”
with David Richeson — November 6 at 7:00 pm

November 2019 Math Encounters poster

“Nothing is impossible!”  While it is comforting to believe this greeting card sentiment — it’s the American dream, after all — there are impossible things.  Ancient Greek geometers and future generations of mathematicians tried and failed to square circles, trisect angles, double cubes, and construct regular polygons using only a compass and straightedge.  Join David Richeson, Professor of Mathematics at Dickinson College and Editor of Math Horizons, to try your hand at some of these unusual geometric construction techniques.  But get ready to fail — after two thousand years, all four of these “problems of antiquity” have been proved to be mathematically impossible!

Light refreshments will be served after the 4:00 pm session and at 6:30 in advance of the second session.

Register for the 4:00 pm session
Register for the 7:00 pm session

Get priority seating for Math Encounters!

Become a premium member (Plus, Squared, Exponential, Infinity) at and get priority seating for Math Encounters.*

Photography notice

By registering for a Math Encounters presentation, you agree that you may be photographed or videotaped by Museum staff and associates.

Books by the speakers

We are happy to offer books edited or authored by Math Encounters speakers through our online shop.

Math Encounters available on YouTube and DVD

Math Encounters presentations are generally posted to our YouTube page within 1-2 months of filming. Due to copyright issues, some presentations may not be reproduced on the Internet. Presentations posted online are also available for purchase via our online shop. Click here to purchase yours today!

Previous Math Encounters Presentations


*For Math Encounters priority seating, premium members must arrive before 3:45 pm for the afternoon presentation and 6:30 pm for the evening presentation.