"And then mum pulls her finger out — we extract the metal ions out — and you're left with just the knot at the end." the most complex molecular knot ever synthesized.

Leigh and his team did something similar, but used metal ions as the "fingers" to keep the knot tying organized. Then tiny molecular strands, just 192 atoms long, assembled themselves around the ions.

We should pay attention to examples from other fields: molecular biology is now drawing upon knot theory for the study of DNA dynamics, and subatomic physics makes use of abstract group theory.