Jo & Jo are celebrating their birthdays. But how many candles should there actually be on the twins' birthday cake? And what is the best way to share this cake among so many guests? And what does the cake have to do with the mysterious Pi? These simple questions are the beginning of a journey on the trail of mathematics.... This is a great leap in time from numerical signs on clay tablets, using pebbles to count, and Greek mathematicians drawing geometric figures in the sand, up to today's electronic calculators and computers. For centuries, people have used numbers and formulas to seek a potential understanding of the world, especially in research, when trying to solved the riddles of the universe, address problems in everyday life, come up with calculations that could result in useful applications, but also address the challenges of a game that full of questions, mistakes, discoveries, and surprises. Upper Austrian puppeteer Andreas Pfaffenberger conducts research on puppet theaters in Berlin, and theater-maker Martina Winkel recount the life and times of Johannes Kepler, our university's namesake, as part of an image-rich shadow play at the Circus of Knowledge. Their new theater production follows the trails of mathematics into a realm of numbers, figures, and inventors.

Suitable for ages 9+