this post was submitted on 20 Nov 2024
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[–] [email protected] 149 points 3 days ago (2 children)

Wording is funky. To clarify:

The rain smell is due to a compound called geosmin. The bacteria that produces it is Streptomyces.

When I taught microbiology lab, I would grow a petri dish of Streptomyces during one particular class and have the students smell it

[–] [email protected] 79 points 3 days ago* (last edited 3 days ago) (7 children)

You mean.... You can ... Bottle up petrichore ??? How come is there no wide range of perfume/candle/lotion and whatnot?

Can I make it at home, if so, how would I go about it with everyday items? Can streptomyces cause health issues?

[–] WolfLink 57 points 3 days ago

There absolutely are petrichor scented things

[–] [email protected] 35 points 3 days ago* (last edited 2 days ago) (1 children)

There's like an indian family/company that's been making some hiqh quality petrichor perfume for idk at least 100 years, probably several hundreds, if not a thousand or more idk.

I forget what it's called you can probably look it up with perfume pertrichor india

edit it's called "Mitti Attar"

[–] [email protected] 11 points 3 days ago

They might've been making it for 10,000 years for all I know. I don't know shit.

[–] [email protected] 16 points 3 days ago
[–] [email protected] 3 points 2 days ago

I have some of this. It smells pretty good

[–] [email protected] 12 points 3 days ago (1 children)

I've never smelled the stuff but apparently the smell of rain is something people try to bottle.

https://www.atlasobscura.com/articles/smell-of-rain-kannauj-perfume-mitti-attar-india

[–] [email protected] 5 points 3 days ago (1 children)

That's the romanticized, traditional Indian cowshit mix trying to approximate it. (Not doing a disparaging stereotype here, that's just literally how the article says they make it.)

I'd be surprised if it actually contains the compound we're talking about.

[–] [email protected] 2 points 2 days ago

i Kind of doubt it. in a video i saw if the process they were using hardfired bricks. i don't believe any organic compounds would survive the heat.

(dung might be a better term for what you were referring to. i seem to remember that because of the way they feed their cattle the dung has a very high fibre content which makes it a good source for building material. it's nowhere as gross as the diarrhea like consistency we get from cows in Europe)

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[–] [email protected] 21 points 3 days ago

Well the smell of rain is actually petrichor, it just has a combination of geosmin and ozone and other chemicals that make that smell.

Geosmin on its own is just a part of it.

[–] [email protected] 20 points 2 days ago

I lost my smell to COVID in that first year, before the vaccine. Recently and for the first time since, I smelled petrichor and I could have cried.

[–] [email protected] 86 points 3 days ago (6 children)

Why would we need such a strong sensitivity to it?

[–] [email protected] 162 points 3 days ago (5 children)

We evolved in the Savannah.
Rain means the watering holes are filling up, which is obviously good cause we need water, but it also attracts prey animals.

[–] DaCrazyJamez 72 points 3 days ago (1 children)

This, of course, was summarized most eloquently at the zenith of human evoloution: the 1982 hit single by Toto clearly stating, "I bless the rains down in Africa."

[–] [email protected] 13 points 3 days ago (2 children)

Oh wow all this time I thought they missed the rains of Africa

[–] [email protected] 6 points 2 days ago

"I guess the rain is down in Africa" for me.

[–] [email protected] 12 points 3 days ago

Some of those rains went unblessed because someone missed them.

[–] [email protected] 38 points 3 days ago (2 children)

You think rain is your ally?

You merely adopted the damp. We Brits were born in it, molded by it. I didn't see dry sand until I was already a man...

[–] [email protected] 21 points 3 days ago (1 children)
[–] [email protected] 8 points 3 days ago

Their spelling was moulded by the US

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[–] [email protected] 7 points 3 days ago (1 children)

I'm still missing something here. For it to be useful, I'd imagine that it would need to inform decisions, and do so where existing senses would fail.

At least in my environment, if I can smell rain, I could also just as easily use my eyes to see the cumulonimbus clouds and say "rain, due east".

In the savanna are there scenarios where the only awareness of rain would be smelling it? Can you derive directionality at 5 parts per trillion? Does it matter?

[–] [email protected] 9 points 2 days ago

you can smell it coming before you see it imo. that gives you time to get to shelter and to move to where the water/food is

[–] [email protected] 10 points 3 days ago (2 children)

Was that area a desert 250,000 years ago?

[–] [email protected] 19 points 3 days ago (1 children)

The whole continent of Africa (as every other continent) went through several major climate changes, small and big. Pretty sure there were at least five major turnovers from wet to dry climate and back since then, and numerous before.

[–] [email protected] 15 points 3 days ago* (last edited 3 days ago) (7 children)

Fun fact, there are some theories that the Sahara desert was actually caused by over foraging from early goat herding.

So to a degree our ancestors may have already caused some climate change.

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[–] [email protected] 44 points 3 days ago (5 children)
[–] [email protected] 14 points 3 days ago* (last edited 3 days ago) (1 children)

Moisture is the essence of wetness and wetness is the essence of beauty

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[–] [email protected] 14 points 3 days ago (1 children)
[–] [email protected] 7 points 3 days ago (2 children)
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[–] ricecake 9 points 2 days ago

It's worth remembering that evolution doesn't select for the best as much as it selects against the worst.

The reason we have such sensitivity doesn't have to be particularly game changing as long as it doesn't make us less likely to reproduce.

You can plainly see our big niche adaptations being used everyday. We think good. We recognize patterns. We use tools. We walk a lot, efficiently and upright. We communicate with high precision. We have a surprisingly efficient digestive system.

We're not busting out the ability to smell rain super often, which hints that it might be more in the "doesn't hurt" category instead of being a big advantage.

My guess is that being able to smell disturbed soil is helpful for tracking, either where an animal has run or where something has been buried. Our ancestors were not above digging up a fresh-ish dead animal a canine had buried for later.
But it could just be that rain sense slightly more accurate than looking towards the horizon was as useful then as it is now: vaguely, I guess? It just doesn't hurt anything.

[–] [email protected] 24 points 3 days ago (1 children)

Maybe an evolutionary trait to locate water?

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[–] [email protected] 62 points 3 days ago* (last edited 3 days ago) (1 children)

Average human male dick length is 2.7cm erect.

Based on my study with a sample size of 1

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[–] [email protected] 11 points 2 days ago

Hmm. Seems strangely on point that Ichor is the blood of the (greek) gods. (Petro- means stone, as in Petro-Oleum.)

Fee-fi-fo-fod

I smell the blood of a god

[–] [email protected] 31 points 3 days ago (4 children)

It's also an off flavor that tasters train for in beer, from water inclusion. It's not good for beer but I don't mind the smell at all

Very beet-flavored to me

[–] [email protected] 34 points 3 days ago* (last edited 3 days ago) (3 children)

Funny you should call it beet-flavor. Geosmin is literally the reason why beets have that flavor :)

[–] [email protected] 17 points 3 days ago (1 children)

Yup! I know, I was an expert taster at a large brewery :)

It was fun! And a little bit ruined some beer for me.

[–] [email protected] 7 points 3 days ago (2 children)

I'm an enthusiastic amateur taster with a terrible palette and I bet it would ruin it for me, too.

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[–] [email protected] 15 points 3 days ago (3 children)
[–] [email protected] 15 points 3 days ago

It is also that.

Petrichor is the smell of rain and is a term like Channelle #5 where it's a combination of ozone and geosmin and other compounds.

[–] [email protected] 9 points 3 days ago (4 children)

Ozone is the smell of an electrical fire

[–] [email protected] 11 points 3 days ago (2 children)

Or poliester fleece or blanket when you hear little sparks.
Some will remember playing with a CRT TV screen 👀

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[–] [email protected] 7 points 3 days ago (3 children)

Diff smell.

I call this 'outside' smell and you can smell it on a clear day.

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[–] [email protected] 5 points 2 days ago (1 children)
[–] [email protected] 5 points 2 days ago* (last edited 2 days ago)

I'd like to see a shark write that more good.

[–] [email protected] 11 points 3 days ago (2 children)
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