Radia Perlman invented the Spanning Tree Protocol (STP) in 1985, the algorithm that made it possible to build large, reliable network bridges. Before STP, network loops would cause packets to circulate endlessly, bringing everything down. Her solution was elegant: organise the network into a tree structure where there’s exactly one path between any two nodes, eliminating loops entirely.
She wrote the algorithm’s specification in the form of a poem:
I think that I shall never see
A graph more lovely than a tree.
A tree whose crucial property
Is loop-free connectivity.
Whimsical!
She’s often called the “mother of the internet,” a title she’s publicly uncomfortable with. Her point: the internet is the work of thousands of people, and attributing it to one person, especially with a gendered title, is reductive. She’s said she’d rather be known for the work than the label.
She solved a fundamental infrastructure problem so well that most people have never heard of it. The story of its development is also a fun one, needs linkage.