You're listening to Part Time Genius, the production of Kaleidoscope and iHeartRadio. Guess what will?
What's that mango mug?
You smell that mug?
Mug like a mug of coffee or hot chocolate or something like that. No, just like pure mug. Can't you smell that? It's like such a strong mug. I'm not sure what's happening here. I can't smell just an empty ceramic mug, can you?
Of course, this place is fragrant with mug right now. I don't know that I've ever smelled mug. What's wrong with me? So nothing? Everyone smells different stuff. It turns out our sense of smell is so complex that there's about a thirty percent difference between what I smell, which is mug, and what you smell, which is nothing right now. But on top of that, new sensor being introduced into our environment all the time, and other sensor disappearing.
What do you mean, sensor disappearing like going extinct or something.
Yeah, sometimes there are flowers that don't exist anymore. Civilization evolves, but the case of the disappearing sense is a little more complicated. And that's something I thought we could tackle today.
I love it. I find that super interesting. So let's dig in. Hey, their podcast listeners, welcome to Part Time Genius. I'm Will Pearson and as always I'm joined by my good friend Mangesh Shot Ticketer and sitting behind that great big booth. Oh wow, I was wondering what he was going to do there.
So for all of our listeners, we have this gigantic whiteboard that rotates. You know, I can flip to the other side. And usually Dylan is pretty humble and sort of subtle about what he does, but I could tell he was very excited, and right as I went into this, he flipped the board and there is the most accurate, anatomically drawn picture of a note.
I mean, we were.
Talking brazen artist or medical student.
No, and that big of a show off.
He was really in this for the big reveal. But anyway, let's dive in mango. What can you tell me about disappearing smells? Let's get right into it. To understand why certain smells have disappeared, we need a little primer on the science of smell because it is super complex. So let's compare smell to the way we see light. Scientists figured out in the nineteenth century that all the varied hues from red to violet are produced by just three
types of receptors in human retinas. But the nose, or rather the clump of sensory neurons that are high inside your nostrils, boasts about four hundred receptors, which is obviously
way more complex. In two thousand and four, Richard Axel and Linda Buck were award the Nobel Prize in Physiology or Medicine for discovering that on these receptors there are genes that encode them, and these genes sit on top of specialized neurons which shoot information down leggy axons into the brain, eventually landing on one of two olfactory bulbs. And this is where the smells are processed. But here's the thing, we don't actually know which smells those receptors recognize.
All right, So I'm scribbling down some notes here. You know, I'm a pretty good note taker. So I've got hundreds of receptors responding to some smells, driven by genetic encoding that sends those smells down into the old factory bulbs in your brain. All so you can go, mmmm, saffron, Did I get that?
Right, Yeah, especially the saffron part.
But nailed it.
On top of how your brain receives this information, you know, the input of smells is much more complex than light. Light is electromagnetic radiation, and the same three colored receptors can combine to process a range of wavelengths covering the entire rainbow of visible light. But smells aren't wavelengths, and they aren't coasting along a smooth spectrum. They evolve a complex mix of chemical particles, all kind of bobbing around
in the air. So, in fact, there's this twenty fourteen paper, it was in the journal Science where researchers at Rockefeller University estimated that humans can distinguish, give or take at least a trillion distinct smells on planet Earth. Plus all those odor receptors have lots of variants, like some of them are less sensitive or fully non functional in large chunks of the population.
Which is wise you were talking about. I guess you and I have about thirty percent variation between what we can each smell, Like some of my receptors are more sensitive than yours and vice versa.
Right, So maybe you walk around smelling all sorts of stuff that I've never smelled. But you know, additionally, there seem to be about six hundred smell pseudogenes.
Wait, so what's a pseudogene? I mean, I fully know what a pseudo gene is, but I mean, for our listeners, what can you tell them what a pseudogene?
You're right, you had that pseudogen poster over youre at bed in college. But it's for our listeners. A pseudogene is a non functional segment of DNA that resembles functional genes, and scientists think that there are about six hundred smell pseudogenes that don't code for working receptors in anybody alive today.
Oh wow, so it means they just don't work or what.
Yeah. So some researchers take this chunk of dormant DNA as evidence of the noses terminal decline. But basically the theory is that we used to be able to smell stuff that we can't smell anymore.
That is so interesting, And is this nasal decline something we should be worried about as a species.
I don't think so. I mean, we aren't the only species that this has happened to. Bottlenosed dolphins and whales gave up a lot of their sense of smell long ago, possibly to free up headspace for echolocation.
Huh. I mean, but those are both underwater creature. So why do you think we're losing our precious sense of smell?
Well, I mean, there could be a couple of reasons. One is evolution, right, like, our sense of smell started roding when we changed the way we select our mates and prioritizing other factors above scent.
That's not tracking for me because that's actually how I chose my wife, But either way, go on, Okay.
Well, the second is pollution. So basically, pollution particles can pass through the olfactory bulb and directly into the brain, causing inflammation. In twenty sixteen, a team of British researchers found that tiny metal particles in human brain tissue have appeared to have passed through the ol factory bulb, which is you know, it's obviously scary.
Yeah, yeah, you know. One thing I was thinking about just the other day that it's the fact that we sort of all took the sense of smell for granted until COVID.
Yeah, it's true. I mean, obviously there are like chunks of the population who don't have a sense of smell, but COVID definitely made that concern more mean stream And you know this happened to me, like I used to have a much better sense of smell until I had COVID, and then I haven't fully gotten it back.
M M, yeah, I remember pre COVID used to be a much better three point shooter. I think something about COVID just really yeah, gotcha there. But it's so weird, like we experienced so much through smell, and until you lose that sense, you kind of take it for granted. And of course everyone knows smells play a much bigger role in triggering memories, sort of like PRUSD with his part. You know, I was going to say madelines, but but
sure is passing gas too. But when you were talking about sinse that have disappeared, I was thinking about how they're scientists actually trying to recreate smells from the past. But before we get into that, let's take a quick break.
Welcome back to Part Time Genius, where we're talking about disappearing sense. So will. Before the break, you were telling us about how scientists have begun to recreate scents from the past using biomolecular tech, which you know sounds fascinating.
It really is, all right, So most smells stem from biological materials. You've got plants, foods, human animal bodies, all sorts of biological materials like that, and they decay rapidly, evaporate into the air, and once the source of the smell is gone, the smell has disappeared. But if they are imperceptible biomolecular residues left on these items from the past, you think of things like incense burners or perfume bottles, cooking pots, food stores, jars, all sorts of things like this.
Scientists can use chromatography to basically decode the smells, and one German researcher has used some of these residues from archaeological artifacts to reconstruct the scent of a five thousand year old oasis. This was in Saudi Arabia. It's so interesting.
That's amazing. But I want to walk us through what chromatography is actually.
I feel like you should explain it, Manga, because I know what a huge chromatography head you are, so this is all you.
I mean. I did do a lot of chromatography and gel electrophoresis and stuff like that. When you know, I worked in a university lab in high school. But it's been it's been a while.
Yeah, it's been been a minute. But simply put, chromatography is a process for separating components in a mixture, combined with mass spectrometry, which can detect different compounds. By calculating the weight of different molecules, scientists can essentially reverse engineer the way a perfume smelled, and they do this by using the molecules left in the bottle.
So then you could like potentially buy a perfume and smell like an ancient Egyptian.
Not just any ancient Egyptian, you could actually smell like Cleopatra herself.
What that's insane?
Yeah, I know. Cleopatra wore a perfume called mendagean and sometimes referred to as the chanelle number five of ancient Egypt. Amazingly, the ancient Egyptian hieroglyphics and documents describe recipes for several perfumes, including this one, but the precise ingredients and preparation methods those aren't quite as well known. So this Egyptologist named Dora Goldsmith, and a historian of Greco Roman philosophy and science,
named Sean Coughlin. They started experimenting with the ingredients. They were looking at things like desert date oil, myrr cinnamon pine resin, and they eventually produced the scent that they suspect approximates what Cleopatrick wore. Is this very strong, but pleasant, long lasting blend of spiciness and sweetness. Apparently, it's pretty cool they were able to recreate.
This, which you know, is fascinating, but it sounds a little more like trial and error of using a recipe rather than just going back to the molecules.
Right, yeah, I mean there are two distinct methods. The EU funded project ODOROPA puts it like this, if you're working from a historical recipe, as the Cleopatrick perfume people did, quote recreating a scent. Now, if you're using chemical analysis techniques of actual ancient scent molecules, you are then quote reconstructing it. So researchers at ODOROPA have even created this heritage smell library that documents historically significant smells.
Oh wow.
They yeah, they've reproduced the smell of the library at Saint Paul's Cathedral in London of potpourri from the seventeen fifties and even Royal Car P five B.
Royal Car P five B what is that?
That would be the car used by Queen Elizabeth the second. So they were able to reconstruct the smellscape of the interior based on this analytical data.
That is so weird. I really hope that long after I'm dead, no one tries to reconstruct the scent of our prius because that would be all. But how exactly do they capture these, you know, historic scents.
Well, according to this one researcher, Cecilia Bimbibra, she uses a method called the headspace technic where she places an object inside a clean sealed bag, has this valve on it, and then they seal the volatile organic compounds. These are the things that actually make up the odor. Then she inserts an absorbent carbon fiber into the valve to soak up the ambient compounds that have been isolated inside, and once the carbon fiber is all loaded up with organic compounds,
she runs it through a gas chromatographer. In the end, it gives her this sort of electocardiogram, but really more for smells, I guess, which she can use to identify the various chemicals in a smell.
I feel like you just have like a word salad of scientific words. But it is it sounds pretty amazing.
One day you'll understand it's pretty complicated.
It is also wild to learn about, like the very precise and almost like clinical process of unpacking what is such a human experience, right like, because you know you said it before, smell is so emotional and whether it's pheromones or childhood memories or just the way home smells,
right like, these are very human experiences. And you know, one of the things I thought was fascinating was I found this study from twenty twelve where two researchers interviewed thirty residents of Krakow in Poland, and they were all old enough to remember the transition in nineteen eighty nine out of communism, and they tracked that transition with the smell of their neighbors cooking. Like the smell showed them the degree to which they lacked privacy in these socialist flats,
and that all changed in the transition to capitalism. This was kind of mind blowing to be in the nineteen forties Russians distanced themselves from capitalist America through smell. It was like one of the propaganda things, and communists felt that they were living in a fragrant world where everything smells, while Americans only experienced land sterile air.
Wow. So I guess capitalism literally smells different than socialism. Yeah, which actually.
Makes sense, right. So think about how different cities have a smell, like these potpourries of everything that contributes to that city's culture. Like there's a distinct smell when you land in Beijing. I know when I've been to Bangalore, like in the monsoons, there's a distinct smell there and it immediately evokes certain memories. America has this too. I was talking to a friend who was telling me how the Denver airport has this distinct smell to her, and
so does the Path train in New York. But what's interesting is that some cities and countries are actually making an effort to recognize the value of their odors. So in two thousand and one, Japan's environment minister classified the country's top one hundred best smelling spots, which ran the gamut from hedges to grill deal.
I'd actually love to see this list, and it definitely makes sense for a country that prides itself on stopping to smell the scent of nature and forest bathing.
Yeah, but Japan isn't the only one. In istanbul Coach University's Research Center for Anatolian'sviations has opened an exhibition called Sense in the City to explore four thousand years of civilization through its smells.
There is something just so cool about the fact that you can land in another country, take this deep sniff and go yep, that's Athens.
Yeah, it's a huge component of travel experience. There's this professor from Goldsmith's University, Alex Rhees Taylor, who specializes in multisensory experience of urban space, and he says, quote, you can learn a lot about a city's economy, a lot about its culture through the sense of smell. But he also says that a lot of those specific smells are starting to disappear and are being replaced by what he
calls a transnational aroma scape. And he goes on to say this it is pretty much the same in every global city now. Smells of pulled pork, flat whites, roasting coffee beans is an increasing one, and microbreweries. There's a global constellation of transnational aromas and flavors associated with transnational class people that move around from city to city.
I guess that's the smell of globalization.
Yeah, kind of like the macdonalization of culture. Yeah.
Well, there's this community hell belief that the modern era has been one of deodorization, that is, the belief that we've gotten less smelly the more that we advance. Sure, but what's interesting is that this isn't entirely true. So first of all, we've been dividing and judging people on the basis of smell for centuries. Socrates thought that slaves smelled differently and that the use of perfumes threatened to confuse the ability to tell them apart from free men.
That is so weird. I feel like the more you learn about so creates less cool. He seems to be.
Yeah, good callback to Bill and Ted there. And it can start to get pretty discriminatory, as you pointed out, with kind of racists and colonial ideas that actually aren't accurate. Historian Mark Jenner has written how when society has quote deodorized ourselves to an extent, we've swapped one set of smells for another, like fabriz plugins in every bathroom or hospitals smelling like bleach, those kinds of things.
Yeah, or like pine trees hanging in every uber. But right, you know, back to what you were saying before. Because smell is so emotional and really so cultural, it can actually have a lot to do with power. So in the early twentieth century along the California coast, there was an odor of squid and sardines that really polarized opinion. The tourism industry thought this fishy smell was intolerable, but
you know, the fishing industry just considered it. This minor note in the smellscape of modern ray and environmental historians look at examples like this to see how conflicting interpretations of the same smell tend to be adjudicated according to who has more power.
I always thinking about that. Speaking of power, remember at the beginning of the episode, you were actually talking about how there are organic materials that are disappearing so their sense will be extinct soon.
Yeah that was a long time ago, but yes, I remember that.
Yeah. Yeah. Well there's this one smell in particular that is extremely sought after by hot, rich people and it's called ood.
Oh I know oud, but not because I'm rich or hot, I just like colones.
Well then you probably also know that ood is in a lot of luxury fragrances from brands like tom Ford, Christian Dior, Joe Malone. But real ood comes from the resin of wild agerwood trees.
Oh, I had no idea where the sun came from.
Yeah, and apparently those trees are under serious threat from over harvesting. Kilo for kilo, ood is actually more costly than gold. And as wild harvesting has been banned in Thailand and other South Asian countries, this is where the agerwood trees grow. There's been a boom in plantations growing
cultivated agerwood. But cultivated ood just isn't that good because it tends to get harvested when the trees are between five and ten years old, and generally speaking, good ood you want to let the trees cook for really about one hundred years, so a lot lot longer.
Yeah, I let that ood cook. But that's right. But you know, Wil, there actually is precedent for recreating sense from extinct plants. Well, that is super interesting and I want to get into that. But before we do that, let's take a quick break. Welcome back to part time genius. We're talking about disappearing sense, all right, Mango, you were just about to tell us about scientists recreating scents and smells from extinct plants. I mean, the whole idea of
this is really cool to me. But actually, do you remember in college I had an extra science credit I needed to take, and I was looking through the options and I almost took organic chemistry because you know, one of the things that said in the pathleot was that you could learned to create the scent of pairs and a lab. And I really love that.
I love that that was like the reason you were going to take what was probably known as like the hardest weed out class in all of college. It would have been a.
Disaster, I know. And actually you're the one who convinced me not to do it, because I chemistry, but the curiosity about how to make sense and a level almost tricked me into hating my senior year. But I hear you,
let's talk about these extinct flowers. So in twenty sixteen, a team of biologists, researchers, and artists embarked on a project called Resurrecting the Sublime, and using tiny amounts of DNA extracted from specimen of three flowers, a team of scientists used synthetic biology to predict and resynthesize the gene sequences that could encode for fragrance producing enzymes and then using those findings, this smell researcher and artist named Cecil
Tolas used her expertise to reconstruc the flowers smells in the lab, and she used identical or comparative smell molecules.
Some guys, since she's like one of these super smellers that helped create perfumes. But what were the extinct flowers?
Yeah, she's a nose like that's what they're called. But yeah, I'm gonna murder the pronunciation of these flowers, but bear with me. The Hibiscadelphus wilderaneus or maui how kiwaii?
You murdered it?
It's the plant's habitat was decimated by colonial cattle ranching and the final tree was found dying in nineteen twelve. And then the second flower was the falls of the Ohio scurf pee, which was last seen in eighteen eighty
one on Rock Island on the Ohio River. And then there's Windberg cone bush, which sounds like a person, but it's actually a flower, and it was last described in London in a collector's garden in eighteen oh five, and its habitat in Cape Town, South Africa was already lost to colonial van so you know it had disappeared there and then was preserved in London for a bit.
Yeah, I mean, I do think it'd be so amazing to smell extinct flowers, But I guess you'd have to go to a lab where they recreated them. It's not like you can, you know, send off these smells or anything.
Yeah, I mean, there's something amazing about like the idea of smelling a new scent, right, Like it's like seeing a new color or something. It just feels unimaginable, But you know the idea of sending smells is pretty fascinating. In twenty fourteen, a Harvard professor named David Edwards and one of his students, Rachel Field, invented a prototype called the O Phone, which was designed to let people send smells like text messages.
WHOA, so, how does that even work?
Well? The phone had a lot of moving parts. There was the O snap app where you create an O note, which was a photograph and a smell created out of a palette of thirty two cents available in the app that could be combined into three hundred thousand possible combinations.
So like the sender would forward the OH note to an OPhone, the hardware portion of the enterprise which recreated the aroma from the O snap app, and the key component of the OPhone is the O chip, which you know created the actual smell.
Yes, I mean, I guess you're not really sending a smell. You're more like describing it to a computer, and the computer squirts out its best guess as to what you described. It kind of makes me feel like it's smell a vision, but for a phone.
Yeah, pretty much.
But it is approximating a mood through smell, And it's sort of like those fancy candle stores that now you know, make these really specific smells to evoke a certain mood, like pasta water or video store or things like that.
I love that video stores a smell.
Yeah. The company that makes it describes it as quote, aromas of buttery, popcorn, plastic vhis tapes, dusty carpet, and hints of candy to evoke the atmosphere of a classic video store. And you have to admit, when you hear those words, you can start to like smell it.
Yeah, bring me back to my days working at biz art. It's like, yeah, the closest thing we have to time travel. It's amazing and I guess until we get our OPhones working, we'll just have to rely on these candles. Anyway, I really am amazed that you can recreate all these ancient scents.
Yeah, it is pretty stunning. All right, Well, before we sign off, how about we make time for a little fact off.
Yeah, I'm into it.
Okay, Mango, here's a quick one. Did you know that Yale University found that Crayola crayons are one of the twenty most recognizable scents among American adults, and another survey eighty five percent of people remembered their childhood when they caught the scent of Crayola crayons.
Which I guess makes sense. But uh, what were some of the other scents on Yale's list?
Well, some of them aren't that surprisingly. There are things like coffee, lemons, bleach mothballs, which is such a strong and terrible smell, baby powder, but also other name brand things like Ivory, soap, Vix, vapor rub, but weirdly, the Krayola scent comes because it's a derivative beef tallow or beef fat, which gives the crayons their sort of waxy feel.
So, speaking of Crayola, here's one I didn't realize from mental fluss. Did you know that? In nineteen ninety four, Crayola released a line of food scented crayons called Magic Scent. Have you heard about these?
No? I had not.
Yeah, so it sounds like such a bad idea because the crayons basically came in flavors like coconut, cherry, and chocolate, which obviously makes kids want to stuff them in their faces.
I mean, how would they not see this coming? Between beef flavor and those dessert flavors. How could you not eat? I think I would try them.
Yeah, But by nineteen ninety five, the next year, apparently at least ten kids had eaten a lot of crayons. So Crayola changed the flavors to things that are a little less appetizing, to things like, uh dirt.
Apparently all right, Well, here's another one from a fragrance manufacturer called Aromaco, who says that in the not so distant future, sweat maybe used like a fingerprint. According to the site quote, Israeli Kimis say that the food we eat, drugs we take, gender, and even state of mind all combined to make each person sweat unique, which is super interesting. It makes sense. But I had not thought about that before.
And the manufacturer points to how Tel Aviv University's School of Chemistry has this lab where a team has been breaking down the components of human sweat. Is kind of a new id that's crazy.
Yeah, So here's a quick fact from Scientific American. I'm not sure if you've ever noticed this, but there's a sweet, slightly pungent smell that comes before the rain begins, and that smell is ozone. That's what ozone smells like. According to tropospheric chemists from the National Center for Atmospheric Research, the downdrafts that happen as a thunderstorm is brewing carry the ozone from the atmosphere down to nostril level where we can smell them.
Wow. I mean, there definitely is a distinct smell there. I had no idea that that's what that was though. All right, well, speaking of recreating sense, the Jorvik Viking Center in York, England, decided they wanted to give visitors a better sense of what it felt like to be in a Viking village. So, as Freddale, a scent consultant, put it, previously, museums were a series of glass cases which had their own musty smell, but not the one
that encouraged you to think about the past. So among smells that are pumped through the exhibits are things like wood, smoke, apples, fish, leatherwork, and goat pooh.
Well, speaking of goat pooh.
I think I accidentally set you up here. I'm not sure I like where this is going.
So this is a terrible fact and you did accidentally set me up. But have you ever heard of perosmia?
I don't think I have.
Apparently it is a scent disorder. So there's anosmia, where you can't smell anything, and then there's phantasmia, which or phantosmia, which is it's kind of like a phantom limb, you know, so you're smelling things that don't actually exist, the same way people with phantom limbs feel like they have a leg even though it's been amputated. And then there's parosmia, which is just awful apparently it affects a very very small part of the population. But everything smells like sewage
and mud. It's just miserable. I read this account from this person in the Guardian who talked about getting this awful cold and illness and it took away her sense of scent. And then she got phantasmia first, where she thought she was smelling a burning meat, so she kept having her husband check the oven and look around the house and it was just this made up scent in her head. But then the worst thing happened and she
got parosmia, and suddenly everything smelled terrible. She lost her appetite, everything felt disgusting, and she thought she was losing her mind. So actually, this is her quote from the article. To me, chocolate tastes like biting in raw sewage, chicken is muddy and rubbery, Peanut butter and marmite are like trying to eat. I'm not gonna say it, but let's just call it
loose motions. And she says there are a couple of exceptions. Raspberries, carrots and parsnips don't taste vile, nor does gin, which really helps. But you know, she didn't know what to do about this. She goes to a conference with people who suffered sort of these three similar traits, and she learned some hacks to deal with the situation.
I mean, this just sounds brutal, but like, what kind of hacks did she learn?
Yeah, basically masking the scent. So her friend, who was a perfumer, made a strong scent out of violets and lilies, and that was something she could actually smell. So she puts that on herself to sort of, you know, cover up everything around her, and she carries around what she calls a perosmia first aid kit. This includes things like cinnamon drops to make drinks palatable and hot sauce to mask the taste of food. And you know, all of it just sounds so miserable.
Yeah, it really does. I feel like we need a palate cleanser for that last fact. So here's one that I think is fascinating. Did you know that during the two thousand and eight World Series, the Tampa Bay Rays Stadium commissioned a scent called Citrus Burst, so that when fans entered the rotunda, instead of smelling hot dogs and stale beer, they would smell the pleasant scent of oranges.
I like that, but uh, don't they play at traffic out of field?
That's exactly right, so it has extra a meaning. But the experiment went over so well that stadium owners started playing and pumping other scents into the stadiums just to please fans, including cotton candy and tops bubblegum.
I love that. You know, you did a nice job of covering up my perosbia fact. So why don't I give this one to you?
I was going to say, even if I had not earned it, just that fact alone, I think by default I'm going to get it. But thank you so much. That is it for this week's Part Time Genius. Thanks so much for listening. If you like Part Time Genius, don't forget to raise the show, write his review, tell a friend, and if you really want to get to us, write our moms a note at PT Genius moms at gmail dot com. They always pass these notes along to us.
Yeah, they passed a few already, which are really really wonderful. And I actually have a giveaway I mentioned this last week, but we're gonna pick ten more random fans from everyone who writes in, and I'm going to send you a special gift to show you our appreciation. We're going to pony you express it to you. So let us know what you think about the show and what topics you want us to cover, especially that, and we'll put something in the mail for you from Will, Dylan, Marry and me.
Thank you so much for listening. Part Time Genius is a production of Kaleidoscope and iHeartRadio. This show is hosted by Will Pearson and Me Mongagetikler and research by our good path Mary Philip Sandy. Today's episode was engineered and produced by the wonderful Dylan Fagan with support from Tyler Klang. The show is executive produced for iHeart by Katrina Norvel and Ali Perry, with social media support from Sasha Gay,
trustee Dara Potts and Viney Shorey. For more podcasts from Kaleidoscope and iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows.