There is a sound coming from a mile beneath the surface of the Caribbean Sea. It has been there for millions of years. It travels through cold, dark water at four times the speed of sound. And for the entire history of human civilization — every war, every invention, every empire that rose and collapsed — we heard it and called it noise. We were wrong. In 2024, an MIT research team fed 9,000 recordings of that sound into an AI system originally built to crack military-grade encrypted codes. The algorithm ran. The team waited. And when the output appeared on screen, the room went completely silent. Not because of what they expected to find — but because of what they had no framework to explain.