![](https://images.newscientist.com/wp-content/uploads/2024/05/09194606/SEI_203361737.jpg?width=1200)
Light reflecting off the round rim creates a mathematically significant shape in this coffee cup
Sarah Hart
The following is an extract from our Lost in Space-Time newsletter. Each month, we hand over the keyboard to a physicist or mathematician to tell you about fascinating ideas from their corner of the universe. You can sign up for Lost in Space-Time for free here.
The artist Paul Klee famously described drawing as “taking a line for a walk” – but why stop there? Mathematicians have been wondering for five centuries what happens when…