You probably know that when a water bottle in a freezer reaches zero degrees, its volume changes, causing the bottle to explode. If you've studied thermodynamics, you may know that magnets gradually lose their magnetic charge when heated. These are both examples of phase transition, which athough seen in everyday life is very difficult to prove mathematically. Hugo Duminil-Copin won the prestigious Fields Medal in 2022 for his work on the topic. He joined us for Perspective.