7 ms·
Poor human olfaction is a nineteenth century myth
- 082349872349872 4y agoIn one of his memoirs, Feynman empirically tested his own sense of smell and came to the same conclusion.
- dclowd9901 4y agoCould you recommend one of his books? I’d like to read some Feynman this year but I have no idea where to start.
- andyferris 4y ago"Surely you're joking, Mr Feynman" I think is the most famous and is quite enjoyable.
- JackFr 4y agoAlso I recommend “Genius” by James Gleick which is a fantastic biography of him.
- dorkwood 4y agoHere’s an excerpt from Surely You’re Joking, Mr Feynman! If anyone’s curious: “Then I looked at the bookshelf and said, ‘Those books you haven’t looked at for a while, right? This time, when I go out, take one book off the shelf, and just open it—that’s all—and close it again; then put it back.’ So I went out again, she took a book, opened it and closed it, and put it back. I came in—and nothing to it! It was easy. You just smell the books. It’s hard to explain, because we’re not used to saying things about it. You put each book up to your nose and sniff a few times, and you can tell. It’s very different. A book that’s been standing there a while has a dry, uninteresting kind of smell. But when a hand has touched it, there’s a dampness and a smell that’s very distinct. We did a few more experiments, and I discovered that while bloodhounds are indeed quite capable, humans are not as incapable as they think they are: it’s just that they carry their nose so high off the ground!”
- remarkEon 4y agoWhen I was a kid my doctor discovered that I had planned to join the military, and was devastated as he had imagined me to become a surgeon or physicist, so he gave me Surely You're Joking, Mr Feynman as a gift on my 18th birthday - as a way to convince me the military was a bad idea (somehow, I still don't understand why he thought this would work). Anyway, I read it in one weekend, and remember the part you're quoting. I learned things about attention to detail in that book that are very hard to teach. Isn't there another story about how he broke open some safes? I'm remembering as much, at least. I need to read it again. I'm double that age now, so it's about that time.
- salad-tycoon 4y agoWhat I remember is a story about a file cabinet that he wanted unauthorized access to, not exactly a safe but similar.
- pilotneko 4y agoYeah, during the Manhattan Project he broke into everyone’s locked filing cabinets to prove that the security measure was basically for show.
- ReflectedImage 4y agoA lot of smelling requires your nose to actually be next to the floor. We don't exactly do that anymore.
- hackernewds 4y agoSeems like an advantage to be able to smell prey and predator. Why didn't we evolve (ie naturally select) humans with stronger noses.
- maximus-decimus 4y agoWhy did dogs not evolve better eyes?
- hackernewds 4y agoBecause they did not start off on their hind legs, and lose vision benefits by getting closer to the ground
- unlikelymordant 4y agoDoesnt that answer your question? If humans vision benefits are so good, and being close to the ground is bad, then the need for a strong sense of smell is greatly reduced.
- mannyv 4y agoI've had dogs for a while, and at least for my dogs they use their eyes and ears more than their noses. I've tested this a few times with steak, and using their nose is a last resort tactic.
- illiarian 4y agoIt's likely an optimization: if you see your prey/steak, you don't need smell to follow it. Brains (not just dogs') are full of such optimizations.
- msla 4y agoOliver Sacks came to that conclusion: https://en.wikipedia.org/wiki/The_Man_Who_Mistook_His_Wife_for_a_Hat https://en.wikipedia.org/wiki/The_Man_Who_Mistook_His_Wife_f... > "The Dog Beneath the Skin", concerning a 22-year-old medical student, "Stephen D.", who, after a night under the influence of amphetamines, cocaine, and PCP, wakes to find he has a tremendously heightened sense of smell.[7] Sacks would reveal many years later that he, in fact, was Stephen D.[8]
- maximus-decimus 4y agoIs that reproducible? If I do meth, cocaine and PCP together, will I forever have superhuman sniffing powers?
- bee_rider 4y agoYou may perceive yourself to have superhuman sniffing powers, depending on how late into the morning your bender goes.
- steve_adams_86 4y agoWhen I take stimulant medication for ADHD it makes my sense of smell more acute (sometimes to a noxious degree, unfortunately; I already sense smells more than most people even without the meds). It seems to be a thing, though. I’ve heard similar remarks from other folks with ADHD.
- nerpderp82 4y agoJust cause yourself to have a migraine, or go on oxygen.
- lelanthran 4y agoProbably a hallucination.
- neilk 4y agoFor the last few hundred years, huge numbers of European-descended men took up tobacco. Moreover, cities were grossly polluted. I wonder if that affected the intuitions of scientists, who were mostly from such places. Maybe they really couldn’t smell very much.
- bobthepanda 4y agoAlso, horse powered transport overwhelmed the senses by producing a lot of horse poop and dead horses. A million kg of horse poop was shoveled out of New York City every day.
- netrus 4y agoMy brain-teaser back-of-the-napkin skills tell me that's also the order of magnitude of human poop produced in NYC every day (I'd think its closer to 2-3 million kg)!
- aflag 4y agoThough at least 50% of it doesn't happen on the streets.
- Viliam1234 4y agoNow let's do the estimate for San Francisco.
- kqr 4y agoAlso known as a Fermi estimation, in case you (or someone else) didn't know.
- geoduck14 4y agoIn school, I was preparing for a presentation about some electrical component we created. One of the questions was "how did you arrive at the proper input voltage". My buddy wrote down "guess and check?" - which I replaced with "Newton Iteration". That was one of my prouder moments
- Llamamoe 4y agoToo bad that nowadays our jaw development is so compromised and allergies so common that just about all of us have deviated septums and nasal cavities too narrow and misshapen for enough inhaled air to reach the right receptors. I'm, for one, barely capable of smelling anything, heh.
- steve_adams_86 4y agoInteresting. I have chronic allergies and narrow nasal cavities, but my sense of smell is very sharp. In fact I smell a lot of things I really don’t want to just about every day. I can smell my family members across rooms, smell dog poo that wasn’t picked up on the sidewalk long before I walk close to it, smell fumes from traffic very easily. Allergies dampen it but I can smell more than I need to all the time. There’s one weird part though. I can’t seem to smell pee very well. When my kids were smaller and would get pee on stuff I’d never notice. Clothing, bedding, etc. To this day I have no idea why I can smell someone’s dirty hands from several feet away but I can’t smell pee. Everyone can smell pee, I think. As a result I always assume I probably smell like pee but have no way of knowing.
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- Sunspark 4y agoIf you contemplate all the possible reasons why you might smell like pee, you will have your answer.
- steve_adams_86 4y agoI mean, when you have tiny kids and a hard time smelling pee, it’s tougher to tell. Kind of like you won’t always realize you’ve got baby puke trailing down your shoulder — they’ll get you by surprise.
- isoprophlex 4y agoUnless there's something wrong with you, urine is sterile. And unless you ate stuff that smells (sulphur compounds in asparagus for example) your piss doesn't really smell after exiting your bladder. It only becomes smelly after some time, when bacteria have had the chance to work on it. Or when you're super dehydrated and you're pissing an orange slurry. My smell is pretty acute, but little splashes of urine from the kids are often almost scent-less. Only when they walk around for a while after small accidents do things get noticeably pissy smelling. Do you also not smell aged, rancid piss in the frequently visited (and messily used) urinals at a bar or highway gas station?
- ericbarrett 4y agoWhen I was younger, I was walking through the NorCal redwoods with my family. It was a clear and crisp day, maybe 65F. I strolled ahead of the group by 30 or 40 feet, lost in thought, but enjoying the dim light and the smell of pine needles and duff. After a few minutes along the trail, I began to smell something else. It was...musky. Foreign to the place. A few minutes more and I realized I was smelling human. Sure enough, we caught up to a slower group. After we passed them, the smell was gone. I'll never forget it.
- Fatnino 4y agoYou never been on bart?
- BucketsMcG 4y agoI've heard many an anecdote of soldiers deployed for months in male-only settings who could smell that a woman had arrived on base. They weren't able to describe what they smelled, or how they knew it was a woman, but they just knew.
- inglor_cz 4y agoIn the books of the former Navy SEAL Richard Marcinko (he sadly died in Dec 2021), it is repeatedly stressed that soldiers shouldn't use any cologne or indeed any perfumed soap, because these smells carry a long way in the wild. The plainest soap possible and that's it.
- wrp 4y agoIn About Face: The Odyssey of an American Warrior (1989), David Hackworth mentions about being on patrol in the Korean war: None of us used repellent (Chinks could smell it as easily as after-shave, soap, tobacco, and toothpaste); we couldn’t slap at them (noises traveled loud and far at night). So we waited and reluctantly contributed our blood. and about poor discipline in Vietnam: Guys were using soap, toothpaste, and shaving cream before operations. They were smoking and wearing mosquito repellent on patrol.
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- null_object 4y agoA few years ago I had a medical procedure that entailed not eating for 2 or 3 days - just drinking water. By the end of that fasting period, my sense of smell was immeasurably heightened, and could definitely smell the differing fragrance of other humans walking along the streets.
- tudorw 4y agohttps://aip.scitation.org/doi/10.1063/1.5121155 https://aip.scitation.org/doi/10.1063/1.5121155 A vibrational theory of smell... Is olfaction a quantum thing?
- jerf 4y agoWell, yes. The details of biochemical interactions involved in olfaction involve a lot of quantum mechanics, which also affects the way molecules vibrate. But this is not some sort of "quantum woo" or mysterious thing... it's just quantum mechanics being quantum mechanics, which is, after all, the dominant and most correct theory of how small things perform in the real world, not some utterly mysterious incomprehensible magic. So... of course it's a quantum thing. Everything's a quantum thing, seeing as how relativity, the other dominant and most correct theory of how things perform, is not generally relevant to energy regimes you live in. Things are not specially distinguished by being "quantum things". The surprise would be to find something that isn't. (Which could conceivably include gravity at this point in time, though I think that even if we can't prove it's quantized at this juncture in time physicists would be stunned to discover it wasn't.) It should also be observed that "quantum" does not mean any sort of meaningful "entanglement" mystery is going on. Frankly we'd all have a more accurate view of the world if the word "quantum" was associated with "boring" and "engineering" rather than "mysterious". It isn't that there isn't a bit of mystery there, it's just it's mostly boring and engineering with a tinge of mystery, rather than a whole big box of mystery. It can't be that mysterious if you can pop numbers in one side, run a mathematical crank, and get very accurate predictions out the other.
- tudorw 4y agothanks, I'll take a tinge of mystery :)
- JackFr 4y ago“My dog has a tiny olfactory bulb.” “How does he smell?” “Awful.”