Mirror rooms


Mirror rooms
When completely ready, this file will contain the svg files for cutting of a series of mirror rooms and instructions on how to produce them. For the moment it only contains the SVG files for the last square room we made.


Submitted by


Alba Málaga, Samuel Lelièvre
Supported by: 
We are grateful to the following fablabs for sharing with us their laser cutters, advices and encouragements : •SciFabLab at ICTP, Trieste (Italy) •Fablab Digiscope at DIGITEO labs, INRIA-Saclay (France) •Carrefour Numérique de la Cité des Sciences, Paris (France)

Imagine two people who hate each other but unfortunately live in a room with walls covered by mirrors. How to place their guests in such a way that these will cannot see each other ? If you imagine that everybody stays on place and that people ar points, then we are talking about a mathematical billiard theory problem called a “blocking problem”.

“Blocking problems” and “illumination problems” became already classical in mathematical billiards study and the related translation surfaces theory. We will explain further very soon.

This exhibit is strongly inspired from the paper “Everything is illuminated” by Barak Weiss, Thierry Monteil and Samuel Lelièvre appeared in 2016. Moreover, it helps to explain the main theorem of the paper to the general public in a hopefully more accessible way.

The exhibit is composed of walls cutted in plastic mirrors, floor cut in wood or very strong cartonboard, a laser level to show billiard trajectories, a series of small figure toys  that help us to tell the story… and somebody passionated to explain the whole thing. The joint file only have for the moment the plans to cut the walls and the floor, but we will upload at some point a more detailed explanation on how we make everything work together.


more hands-on