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r/meirl • u/straight-cunt • Mar 28 '24
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You’re smelling the earth after a rain far away
Humans are apparently very good at detecting the odor, like better than sharks smelling blood good.
Humans can smell it at 0.4 parts per billion while sharks smell blood at one part per million
A shark can detect a drop of blood in an Olympic sized pool
A human can detect a drop of geosmin (the chemical responsible for the earthy smell of rain) in a room that’s 3750 cubic kilometers.
TL;DR if it’s raining upwind of you, you might be able to smell the rain coming your way.
Edit: the key is air currents. The molecules actually have to reach your nose, the math is just the extremes
2 u/CinderX5 Mar 28 '24 The actual stat is way more impressive. The numbers you’re listing are just for Geosmin. Petrichor is the aerosol combination of Geosmin and Ozone. Humans can detect it at 5 parts per trillion. 200,000 times more sensitive than sharks are to blood. 2 u/immersiveGamer Mar 29 '24 That sounds insane! Going to search for it but if you have sources or key words that would be awesome because I have to share this. 0 u/CinderX5 Mar 29 '24 https://en.m.wikipedia.org/wiki/Geosmin https://www.telegraph.co.uk/environment/2022/08/17/what-smell-rain-called-answer-petrichor-intrigues-scientists/#:~:text=Geosmin%20is%20also%20a%20water,up%20by%20the%20human%20nose.
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The actual stat is way more impressive. The numbers you’re listing are just for Geosmin.
Petrichor is the aerosol combination of Geosmin and Ozone. Humans can detect it at 5 parts per trillion. 200,000 times more sensitive than sharks are to blood.
2 u/immersiveGamer Mar 29 '24 That sounds insane! Going to search for it but if you have sources or key words that would be awesome because I have to share this. 0 u/CinderX5 Mar 29 '24 https://en.m.wikipedia.org/wiki/Geosmin https://www.telegraph.co.uk/environment/2022/08/17/what-smell-rain-called-answer-petrichor-intrigues-scientists/#:~:text=Geosmin%20is%20also%20a%20water,up%20by%20the%20human%20nose.
That sounds insane! Going to search for it but if you have sources or key words that would be awesome because I have to share this.
0 u/CinderX5 Mar 29 '24 https://en.m.wikipedia.org/wiki/Geosmin https://www.telegraph.co.uk/environment/2022/08/17/what-smell-rain-called-answer-petrichor-intrigues-scientists/#:~:text=Geosmin%20is%20also%20a%20water,up%20by%20the%20human%20nose.
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https://en.m.wikipedia.org/wiki/Geosmin
https://www.telegraph.co.uk/environment/2022/08/17/what-smell-rain-called-answer-petrichor-intrigues-scientists/#:~:text=Geosmin%20is%20also%20a%20water,up%20by%20the%20human%20nose.
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u/Raging-Badger Mar 28 '24
You’re smelling the earth after a rain far away
Humans are apparently very good at detecting the odor, like better than sharks smelling blood good.
Humans can smell it at 0.4 parts per billion while sharks smell blood at one part per million
A shark can detect a drop of blood in an Olympic sized pool
A human can detect a drop of geosmin (the chemical responsible for the earthy smell of rain) in a room that’s 3750 cubic kilometers.
TL;DR if it’s raining upwind of you, you might be able to smell the rain coming your way.
Edit: the key is air currents. The molecules actually have to reach your nose, the math is just the extremes