An alternative definition of pi using football to prove that maths really is the language of the universe… Watch the full video from DuoCon here.

Research on the diving envelope of a goalkeeper:
Kerwin, D.G., Bray, K. (2006). Measuring and Modelling the Goalkeeper’s Diving Envelope in a Penalty Kick. In: Moritz, E.F., Haake, S. (eds) The Engineering of Sport 6. Springer, New York, NY. https://doi.org/10.1007/978-0-387-46050-5_57