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Mathematics

The Pigeonhole Principle and Its Surprising Applications

Quick fact

The pigeonhole principle was first formally stated by Peter Gustav Lejeune Dirichlet in 1834, and it's often called 'Dirichlet's drawer principle' or 'box principle'.

Why this is interesting

If you have more socks than drawers, you're forced to double up. So why does this simple idea help prove theorems about space, numbers, and networks?