Ahh the hot hot summer in San Francisco is finally here, time for some pumpkin spice.
I'm sure you just feel.
WRONG about that, right?
Hey sniffers, I'm Trace, this is DNews!
We got a question from Sydney Flowers asking, "how does temperature affect your senses of
taste and smell?"
And we were all immediately curious about the smell bit… so, we looked into it!
Firstly, we have to understand how the nose knows in the first place!
In today's society, our olfactory system is used mainly to entice and intrigue -- things
like tasty foods, perfumes and colognes they co-opt our sense of smell.
But the nose evolved to reveal information about our environment;specifically, stuff
we can't see, hear or touch!
Smell tells us what's happening with our tribes and clans, tells us if food is safe to eat,
and warns us of strangers (or possible sexual partners).
It can even influence emotional states and initiate recall of memories.
It's powerful, to say the least.
The nose is constantly sucking in air - you're probably noticing that right now.
What's your space smell like right now?
Think about it!
What's happening is: particles are physically entering your body and hitting
specialized olfactory receptors.
Yes, these particles are real.
Yes, when you smell trash you're literally inhaling tiny bits of trash.
Or when you smell a pig farm you're literally smelling particles of… well, you know what
you're smelling.
These particles or odorants are "volatile."
Which is science's name for something that gets into the air at regular Earth temperatures.
Lots of things are volatile substances: plants, animals they are definitely, but steel, ain't.
It has no smell.
Sidebar: seriously, metal has no smell.
Yep, I know you're thinking, I know what pennies smell like (unless you've gotten rid of them
like Canada -- find nickels) . Whatever.
But that smell is just chemical compounds on your skin reacting with the metal -- and
those ARE volatile.
Boom!
End sidebar!
Anyway, temperature can of course affect volatility.
According to a 2003 study in the journal Drying Technology, pine trees release more odorous
volatiles as they get hotter and dryer -- mmm, pine smell.
And another study in Food Analytical Methods rated how strong the smell of salami was at
various temperatures, finding 122* F was the yummiest -- giving off the best odorants and
particles.
But that's not enough, we also have to sense when those particles are being given off!
A 1998 study in Physiology found humans can detect volatiles and particles in air with
as little as 4 femtograms per liter.
That's a decimal point, then fifteen zeros, then a 4.
It's really, really small.
The nose is a sensitive piece of evolutionary equipment, and like any sensitive equipment,
it works better when it's in ideal conditions.
The more humid air is, to a point, the better it traps these particles and lets them hit
out olfactory receptors.
Overly dry air doesn’t trap and ferry those smells to your detectors as easily!
And if you can’t detect it, you can’t smell it.
This detection also decreases at high altitudes, because the air is drier and sometimes there's
just a bit less of it.
Now that we're on the same page with particulates, volatiles, odorants and olfaction; we've sort
of answered our question right?
Sort of.
Winter air is drier, and therefore ferries less odorants and volatiles to your olfactory
receptors.
AND colder temperatures mean fewer odorants and volatiles are coming off trees, and things
sitting around your environment.
So it's not that your olfactory system isn't working as well, the world just has less smell
in colder months.
Lemme paint you a picture.
If you were to sit outside in your front yard and drink hot apple cider, or a pumpkin spice
latte in a hot humid environment, there would literally be MORE smells in the air.
So the nutmeg, allspice, star anise, and so on would meld with the grass, and soil, and flower
pollen…
Weird to think about it that way?
But in the fall, we still get all the smells from the hot beverage; it's temperature is
the same, but the WORLD is colder, so we may only detect some of nature's smells -- not
all.
The final answer, does seem to be, your sense of smell is basically the same… but it works
best when the air is warm, and even better when it's a little wet.
When the air is cold, or dry, there's just not as much smell to smell.
Thanks for your question Sydney!
The thing is, every time you sick in air and particles and odorants, you're also sucking
in microorganisms… and some of those could be dangerously interesting.
I've been watching Monsters Inside Me, on Animal Planet Go, and I have to say the weird
computer animated microbes and crazy infections are so….
addicting!
Check it out as well as all the other Animal Planet shows on the ANIMAL PLANET GO APP!
Free on your App Store.
Knowing what you nose about the schnoz, what do you think space smells like?
Maybe you can guess, but you should probably just watch this video to be sure.
What's your favorite season for smells? Obviously
I love fall, as maybe you've already guessed.