Bought something you don’t need from an ad? Blame it on the algorithm. Disappointing singles on your dating app? Blame it on the algorithm. Come across a post that hits too close to home? Yep, it’s the algorithm. But what exactly is the algorithm, and when did it start shaping how we live digitally? We track the making of the algorithm — starting with ancient Babylonians and Greek mathematicians — to understand the forces filtering what we stream, shop, and see online today.