As raindrops land on soil, they aerosolize molecules trapped in tiny air bubbles on the ground, which the wind disperses. The three primary scents associated with petrichor are ozone, geosmin ...

[Yukio Shinoda] is probably master of the LED bubble display. She started out with an idea, back in 1994, of a column of water and an array of solenoids to inject air, making patterns in the bubbles.