In 1964, two Australian scientists named a smell that everyone had noticed and no one had properly explained. They called it petrichor, from the Greek petra for stone and ichor, the fluid said to run in the veins of the gods. It is the smell of rain on dry earth. Most people recognize it within half a second and cannot say why it feels like something important is about to happen. The science is genuinely strange. What is actually happening The main compound responsible is geo
