Three prisoners of three different species, locked in one cell. One will be executed in the morning, but which one?
The scenario presented in the first video by Mathfigs is a well-known mathematical puzzle that deals with counter-intuitive thinking about probability. Called the Three Prisoners problem, it originated in popular science writer Martin Gardner’s Scientific American column back in 1959.
Mathfigs looks like a high-quality production that could easily have been commissioned by the Lego company. In fact, it's the summer project of a team of academics from the Faculty of Mathematics and Information Science at Warsaw University of Technology.
The inspiration came from mathematics lecturer Dr Tomasz Brengos, who had recently renewed his passion for Lego by playing with his little daughter at home. Dedicated to making maths accessible to young minds, he started wondering if Lego bricks could be his next medium after starring in a live-action pirate themed maths video series (link in Polish).
As it turns out, bringing your toy bricks to the workplace can indeed develop into an educational project. Together with graduate students and colleagues in the maths and IT departments, Brengos brought to life a script he wrote on the prisoners problem.
The team used about a thousand Lego blocks in the production, and recorded the film in a darkened lecture room at the university. To animate the motions of the figurines, they meticulously rehearsed and documented their own body movements, such as walking.
Their work on the first instalment of Mathfigs took place over July and August, and the video premiered at the university during a conference for young mathematicians. It has also attracted nearly 15 thousand views across both English and Polish language versions on YouTube.
Encouraged by the positive response, the academics are now hoping to release a second movie before Christmas. According to the scientists, this time it will be Batman labouring over some scientific concept.
If you’re not familiar with the Three Prisoners, you may have noticed that it’s mathematically equivalent to the more famous Monty Hall problem, based on a TV game show where participants have to guess which of the three doors conceals a prize. Once the participant has picked a door, the show host then opens one of the remaining doors to reveal the prize is not there.
Now that you have watched the Lego version, can you answer this: once you’re down to a choice of two doors, should you switch your choice, or stick with the original pick?