Welcome to our 33rd annual π Day! Help us celebrate this never-ending number (3.14159 . . .) and Einstein's birthday as well. On Saturday, March 14, 2020, visit us for Pi (π) Day, participate in π-related activities, and enjoy a piece of pie. 

Founded at the Exploratorium by our own Prince of π, physicist Larry Shaw, π Day has become an international holiday, celebrated live and online all around the world.

Be sure to share your π Day spirit with #PiDaySF and @Exploratorium.

Schedule of Events

π Activities with the Explainers
10:00 a.m.–4:30 p.m.
Bechtel Gallery 3                            

Join the Explainers for a hands-on exploration of π and add to the ongoing π bead string!       

Sync on a Circle
With Cinema Arts
10:00 a.m.–5:00 p.m.  |  Bechtel Gallery 3

Sync by Max Hattler (2011, 9 min., looping)

Much like π, Sync "is based on the idea that there is an underlying, unchanging synchronization at the center of everything; a sync that was decided at the very beginning of time. Everything follows from it, everything is ruled by it: all time, all physics, all life. And all animation."

Nanojems:® Million Digits of π
10:00 a.m.–5:00 p.m.
Gallery 4 Corridor, Microscope Imaging Station

Look through the microscope to see the first million digits of π engraved on crystal and sapphire gems.

Pi Toss
With Explorables
11:00 a.m.–1:59 p.m.  |  Bechtel Gallery 3

Circles surround us in nature. To describe them, we use the number π, or the ratio of a circle’s circumference to its diameter: 3.14159…. Join the Explorables team to approximate this elusive number by tossing toothpicks onto a lined surface—and counting how many fall across the lines.

V-I-Pi Donor Lounge
11:00 a.m.–2:00 p.m.  |  Fisher Bay Observatory Gallery 6

Innovator-level donors and above are invited to bring their family and friends to the V-I-Pi donor lounge! The lounge will include complimentary beverages and snacks, a safe space to leave bags and coats, a relaxing place for the whole family to take a break, and a V-I-Pi pizza and pie bar at 12:30 p.m. RSVPs appreciated. Questions? Email amoreno@exploratorium.edu.

Why π?
With Ron Hipschman, Lori Lambertson, and Paul Dancstep
Noon  |  Bechtel Gallery 3, Wattis Webcast Studio

Find out what’s so special about the famous mathematical constant. Exploratorium educators and π enthusiasts Lori Lambertson, Ron Hipschman, and Paul Dancstep will share the history and demonstrate the unique properties of this irrational number.

Science of Pi(e)
With Julie Yu
1:00 p.m.  |  Bechtel Gallery 3, Wattis Webcast Studio

Whether your appetite is for pizza or pumpkin, there’s a full serving of science and a slice of math that goes into a pie before it enters the oven. How do you get from a ball of dough to a crusty disc of deliciousness? Get ready for some kitchen calculations and discover how π can help you to a better pie.

Pi Procession
With Mission Delirium
1:59 p.m.  |  Gallery 4
Celebrate circumference and circumambulate the π shrine in our annual parade. Find your (decimal) place in the neverending line of digits to secure your own slice of pie!

Pie Serving
2:15 p.m.  |  Gallery 5

Have a slice of pie on us—while quantities last. First come, first served. One slice per person, please.