Prompt Cast
The Science Behind the Earthy Smell After Rain
TLDR Petrichor, the earthy smell that occurs after it rains, is caused by a molecule called Geosmin produced by bacteria in the soil. Humans have evolved to smell Geosmin even better than sharks can smell blood, and it is being captured and sold in India as Mati Ka Atar and used as a perfume ingredient in the United States and Europe.
Timestamped Summary
00:00
Petrichor is the name for the earthy smell that occurs after it rains, and it is based on two Greek words meaning "stone" and "the fluid that flows in the veins of the gods."
02:17
Petrichor is the earthy smell that occurs after it rains, and it is caused by a molecule called Giozmin produced by bacteria in the soil.
04:34
Raindrops trap little air bubbles when they hit the ground, and these bubbles shoot up through the raindrop and pop into an aerosol, spreading the earthy smell of petrichor through the wind.
06:39
Humans have evolved to smell Geosman even better than sharks can smell blood, which is a significant evolutionary trait that has yet to be fully understood.
08:50
Geosman, the scent produced when rain falls on dry soil, is being captured and sold in India as Mati Ka Atar and is also becoming a perfume ingredient in the United States and Europe.
11:10
During a thunderstorm, the smell of petrichor is actually the smell of ozone produced by lightning.
13:08
Petrichor smells cleaner in the city because there is less geosmin and more ozone, and terpenes also contribute to the smell.
Categories:
Society & Culture
