The Full Story
Ada Lovelace was the daughter of Lord Byron. Her mother, fearing she would inherit her father's chaos, had her taught mathematics instead. It was the education that accidentally changed the world.
In 1833 she met Charles Babbage, an inventor building a machine that could calculate. Everyone who looked at it saw a calculator. Ada saw something a century ahead of its time, that a machine could process anything expressed as symbols. Not just numbers. Music. Language. Logic. Anything. In 1843 she translated a French article about Babbage's Analytical Engine into English and added her own notes. Three times the length of the original. Note G, the last of them, was a step-by-step set of instructions for a machine to follow. The world's first computer programme.
It was published signed only with her initials, A.A.L., because her name was not permitted on the page. Babbage's engine was not built in her lifetime. It was not built for another hundred years. When Alan Turing wrote his seminal 1950 paper on whether machines could think, he referenced her. The US Department of Defense later named a programming language Ada. Every computer programme ever written traces back to a note she wrote by candlelight.
Why This Matters
Babbage invented the engine. Lovelace invented what an engine could be. Her insight, that a computer is a symbol-processor, not a number-cruncher, is the single idea on which every piece of modern software depends. She died at thirty-six, before anyone knew what she had written would matter. She is the only child of Lord Byron to have changed the world, and she did it with mathematics.