Circles and spheres are essential objects in geometry, but measuring them is impossible without the right tools: circle constants. Mathematicians tend to take these numbers for granted, but historically the quest for precision in computing these constants has been a big deal and is worth celebrating today.

That’s why on June 28 (also known as Tau day) AARMS partnered with the Discovery Centre in Halifax to organize a special math event that was attended by approximated 500 members of the public. Four hands-on workshops, where visitors could explore mathematics in a playful way, were held in this ever growing science museum parallel, :

  • Circle Origami, presented by Dr. Eva Knoll (MSVU) showed math tricks related to origami. Visitors built 3D shapes using circular (as opposed to rectangular) paper.
  • Measuring Tau, presented by Todd Mullen (Dal) and Emily Wright (MSVU), consisted in an empirical calculation of circle constants using hula hoops and other circle shapes, and comparing the error in the resulting measurements.
  • Designing wallpapers, presented by Annamieka Aerts (Dal) was a playful art attack where wallpaper symmetries were created by creating a pattern on a painted square block and repeating it on paper support. The math-artists could bring their creation home.
  • Polyhedral symmetries, presented by Rebecca Ryan (Dal) and Jesse Preston (MSVU), used giant triangular shapes created by Dr. Knoll to explore the possible polyhedra that could be constructed in three dimensional space. The shapes were hung from the ceiling of the museum and displayed as artwork for the rest of the weekend.
Dr. Eva Knoll preparing circular paper for origami
Annamieka Aerts presenting a truly hands-on workshop.

An introductory poster and an interactive presentation about circle constants was provided by Dr. Daniele Turchetti (AARMS and Dal), together with a poll inquiring the visitor preferences for using the constant Tau over Pi.

Everything you always wanted to know about Tau* (*but were afraid to ask)

Asmita Sodhi (Dal), who is also a volunteer for the Discovery Centre, prepared a scavenger hunt with the aim of highlighting the mathematics that is already in the museum. There is a lot of it to be discovered, in form of curves, surfaces, patterns, or hidden in the science presentations. Thanks to the collaboration of our little math detectives, we discovered even more math in this museum that what we thought possible!

On top of this the Discovery Centre staff, led by Ryan Jameson, provided us with material and logistic support, and organized their own special math activities: fractal constructions at their Lego boards, and polyhedral building with wooden sticks at the Innovation Lab.

Approximately 500 visitors participated to these math events. The highpoint of the day was reached when the mother of two young math lovers told us that they did a two hour drive from another town just to attend Tau Day. They made our day, and certainly deserved their two pies!

The results coming in: Pi collected 59% of the votes and Tau 41%. Both sides declared it ‘a victory’, the Tau side arguing that their votes counted twice as much.