What is Smell: Definition and 55 Discussions

The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting hazards, and pheromones, and plays a role in taste.
It occurs when an odor binds to a receptor within the nasal cavity, transmitting a signal through the olfactory system. Glomeruli aggregate signals from these receptors and transmit them to the olfactory bulb, where the sensory input will start to interact with parts of the brain responsible for smell identification, memory, and emotion.There are many different causes for alteration, lack, or disturbance to a normal sense of smell, and can include damage to the nose or smell receptors, or central problems affecting the brain. Some causes include upper respiratory infections, traumatic brain injury, and neurodegenerative disease.

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  1. D

    Is there a safe way to eliminate sulfur smell in the floor cracks?

    I have a problem from 3 weeks… I broke a thermometer that contained mercury. The mercury balls hid in the cracks in the parquet in the floor. I found information in some chemical webiste, that the only thing what I can do, is to cover this mercury with ground sulfur to neutralize the mercury...
  2. DaveC426913

    Why does air smell different after using a CPAP machine?

    I've recently started using a CPAP machine, which filters air and pumps it through a water chamber to humidify it. After a night of sleeping with it, I take it off in the morning and, once I breathe normal air, it has a very strong and distinctive smell. To me, it smells like something metallic...
  3. kyphysics

    Can You Describe the Smell of Ammonia to Me?

    I am not sure what it smells like and am wondering if someone can describe it to me. The reason I ask is I am wondering if I have a mouse or rat in the home that is urinating on my clothes. I have read that the mouse/rat urine would smell like ammonia. So what does ammonia smell like? Thanks!
  4. A

    Mom's Bad Idea: Will Bleach Help Cat Pee Smell?

    So my cat peed on the towels(bu the smell not today) It stunk really bad, like ammonia. Then my mom said it will be fine and put them in the washing machine. As she added the bleach I said that would be a bad idea. How wrong is she?
  5. R

    How Far Can a Shark Smell Blood in the Ocean?

    I have read that a shark has great sensitivity to smelling blood from a large distance. In an open, calm sea, just how fast can blood molecules diffuse through sea water for a shark to detect??
  6. K

    What is the smell from the new plastic storage box

    It's a tool storage box, probably made of PP (According to the label) When its lid opened, quite an obvious (but not very strong) smell coming out ,what it could be? vaporized form of plastic?
  7. C

    B What is the Physics behind Smells?

    I was thinking about light and sound and then I thought "what about smells?". What I mean is, what's the physics behind a smell?? Is it a wave, is there particles that you smell?? It sounds weird but I'm really curious about this. I understand it might be in the biology sort-of area but then...
  8. Psinter

    Cat Owners: Do Cats Smell?

    A question for cat owners. One day I hope to get a pet. Until then, I gather information first. I'm primarily concerned about smells. A bunny is on the list yes or yes. I don't care if it smells because I will love:heart: it lots anyways. I was thinking that maybe a cat would be cool too. Just...
  9. S

    Why are Pokemon Exceptions considered code smell?

    "Gotta catch 'em all" e.g. try { // something that might fail for reasons I don't want to anticipate } catch (Exception ex) { // do something } I believe there are justifications for doing this: Inside the try block I'm using a class from a 3rd party library that doesn't have...
  10. N

    What are Some Strong-Smelling Chemicals Used in a Laboratory?

    Hi there Do you all have any chemicals that you can think of in a laboratory that give off a very strong smell and should be used under the chemhood I just used Glacial Acetic Acid today and I had no idea how strong the smell was . from now on I am using it under the chemhood I have created a...
  11. KarminValso1724

    Why do different colors of playdough smell and feel different?

    Shouldn't they all be the same?
  12. Salvador

    Weird smell in nose after inhaling fume

    Hi folks , now I wonder today I was working on a cooling system , I drilled a small hole in a thin metal plate that was painted black, now as the drill goes through the metal it heats up so for a tiny moment there was this smell which i sometimes get when drilling wood for example the only...
  13. Alpha123

    What are the esters formed from fumaric acid and propanol ?

    Homework Statement what are the esters formed by: -fumaricacid and propanol? - succinic acid and butanol -citric acid and methanol and how does each one smell Homework Equations none The Attempt at a Solution I have drawn out each of the structural diagrams but i couldn't draw the esters. My...
  14. bagofbones

    Smoke smell in a flat below mine.

    Good day, everyone, I have an uncommon question: Man smokes in a balcony. Will the people, who are below him will smell that? Or just people who live above the man? I guess warm air is going up, but how about a smell, diffusion says that molecules are moving disorderly, so I completely lost my...
  15. D

    The Smell of Garlic and Enzymatic Oxidation

    Hello, We are working on project at school about garlic breath.Here is the article I have read in Popular Science magazine which gave me and idea.The article was about how to cure garlic breath and it gave some solutions about it.And I find these two(I copied them below from the original...
  16. M

    Does the smell of alcohols increase as molar mass increases?

    Hello, I was just thinking about the pungent smell of alcohols and if they increase as the molar mass of the alcohol increases. For example, if I were to have samples of methanol, ethanol, propan-1-ol, butan-1-ol, and pentan-1-ol all at room temperature, would the alcohol's with the highest...
  17. N

    Gasoline smell does not inginte

    Say there is a chair soaked in gasoline. If someone is to walk in the room the smell is immediate if the chair was lit on fire the liquid gasoline would ignite the chair. However, what about the particles that constitute the smell of it? Why don't they ignite as well? What is the nature of the...
  18. P

    Storing and Transferring smell

    Has anyone ever heard of or know about any technology that could capture , store or transfer smell in any form electronically or mechanically. Are there any researches being conducted in universities or research facilities regarding this topic or have there been any achievements so far. I...
  19. jtbell

    New Car Smell & OnStar: Our Experience with a 2013 Chevrolet Sonic

    Now, if I can just get the thing to shut up... :uhh: Yesterday after work, my wife and I picked up our new car, a 2013 Chevrolet Sonic. Its predecessor was 13 years old, also bought new, so shopping for a replacement gave us a bit of "culture shock." Even though we chose the lowest-priced...
  20. P

    Can we Measure and Quantifying smell? (Dog Experiment)

    So right now I am shadowing a 8th grade science teacher at Drew Charter school and I was helping a student work on his idea come up with a science fair project. The student wants to study what kind of smells do dog's prefer over other's but using household (safe items), food, and dirty...
  21. O

    How to remove the chemical smell from plastic?

    My new plastic toy has a strong chemical smell, does anyone have any suggestions on how to remove this smell? Thanks in advance for any suggestions
  22. tiny-tim

    Flash, burning smell, computer dead: diagnosis?

    when i pressed the power button on my imac g3 desktop computer, there was a bright flash from inside the computer (it has a transparent blue top), and a burning smell such as when a fuse blows i tried using a different power lead a few hours later, the same thing happened again everything...
  23. W

    Solving Smell Problems with After Shave, Hair Gel, Moisturizer & Deodorant

    I'm wearing after shave, hair gel, moisturizer and deodorant. Each of these gives off its own odor. Although they smell nice individually, they smell odd when worn together. I wouldn't say they smell bad, but it smells funny. What do I do? I don't want to stop using one of these. Is there any...
  24. F

    Do your grandparents give off a smell ?

    Do your grandparents give off a "smell"? I don't know if it is just you, but my grandparents give a certain "smell" that distinguishes them from other old people. I've seen other old people and they give off their unique smell. What about your grandparents or any old folks you know?
  25. V

    So what is smell exactly? I'm sorry if this is really basic but I'm

    So what is smell exactly? I'm sorry if this is really basic but I'm quite confused by it. Does our brain produce the smell and it is a bi-product of chemicals? Or is it a wave like sound? Or is it something else? I'm just curious as I know what Photons and Sound is but I've never really heard...
  26. Ivan Seeking

    Medical Can minty mouthwash enhance sensitivity to other odors?

    I noticed something odd and wondered if what I think is happening, is happening. We bought a device that seems to stop cats from spraying, by releasing a pheromone that makes cats happy. https://www.physicsforums.com/showthread.php?t=389106 I thought it was odorless, but, oddly...
  27. D

    How does smell work on the atomic level?

    Do substances radiate particles? Is it the wind brushing up the surface particles of the substance? Do dense materials usually have less smell?
  28. W

    Why do astronauts describe the smell of space as strong, metallic, and unique?

    A recent news article quoted Astronauts as saying space has a distinct smell - "strong, metallic, and unique", also "gunpowder or ozone". Can anyone explain this? http://news.yahoo.com/s/space/20090905/sc_space/spacesightsandsmellssurpriserookieastronauts "WASHINGTON - For rookie...
  29. Ivan Seeking

    Medical FDA Warns of Zicam Nasal Gel Risk to Smell

  30. M

    Different people have different sweat smell ?

    Is it true that different people have different sweat smell ? If so why ? Thank you
  31. N

    The Smell of Space: Mystery & Explanation

    This is just weird, and probably has a good explanation.. But how can a space suit or space have a distinct smell? Could the smell be coming from particles off their space suits? If so, how/why? http://spaceflight.nasa.gov/station/crew/exp6/spacechronicles4.html
  32. B

    Fundamental question about 'smell'

    As I understand it, the sensation of smell is caused by small amounts of matter leaving the body before being incident on olfactory receivers in our nose. Now, since the 'smell' has mass and it is leaving the body, could there eventually arise a situation where some body loses all its mass as...
  33. P

    What adjective is used to describe the blood smell?

    Thanks What adjective is used to describe the blood smell ?
  34. Math Is Hard

    Japan battles the old man smell

    Japan battles "the old man smell" Something weird I heard about on the radio this morning. http://inventorspot.com/articles/japans_aging_population_deals_with_old_man_smell_16746 http://en.wikipedia.org/wiki/2-Nonenal :eek: Gee, I would have thought they were just talking about...
  35. Simfish

    Does the smell of a substance diminish wrt time?

    And if so, how long does it take for the smell of something (say, a perfume, food, or artificial source) to decrease? And is this length significant in the span of say, a human lifetime? I'd expect the smell of a substance to decrease like a function like 1/x. This hunch is based on the fact...
  36. moe darklight

    Why are we so sensitive to bodily odors?

    This is something I've always asked myself: why do we find our own natural scent as a species so repulsive? I mean, think of all the completely unnatural hygienic routines we have to undergo each and every day just to not offend other people with our various odors. It seems like there is a...
  37. I

    What Causes the Smell of Things?

    Smelly stuff? Well what is the cause that something smells. That is what does a substance emit before entering the nasal chamber of our nose that enables us to smell things?? Or does it really emit anything?
  38. Ivan Seeking

    Smell of Spiders: Exploring the Mystery

    The other day I was clearing out some stuff for a dump run when I noticed the smell of spiders. And sure enough they were there - a bunch of biggons. I remember this smell from my childhood when I would sometimes play with spiders. I liked to feed them flies and moths so that I could watch...
  39. P

    Water bottle explosion with acid smell

    At the school where I teach, we recently had a recycling bin door blow off due to an explosion in a water bottle. Lots of heat was generated as evidenced by the melted, hard plastic and there was a sweet acidic smell to the liquid coating the inside of the bottle. The liquid had a pH of about...
  40. C

    Cigarette Smoke Smell: Health Hazards & Time Factors

    Everyone's been in a house or motel room and smelled the residue of tar from cigarettes that stays in walls, carpet and ducts from previous smokers. The important question is does it pose a hazard to health? How much, if at all, does the threat diminish with time?
  41. M

    Investigating the Smell of Strontium Chloride

    I was preparing a solution of Strontium Chloride by reacting Strontium Carbonate powder with some dilute Hydrochloric acid. As expected, the acid reacted with the SrCO3 and began to fizzle (Carbon Dioxide forming in a similar reaction to vinegar and baking soda). I began to detect a slight...
  42. Mk

    The Axe Effect: Smell Good, Taste Better?

    What exactly is the "Axe effect?" Is it good? Should I use Axe? Which flavors (I like flavors, since... nothing else works for the olfactory sense) are better? I heard some are stinky... tasting. By tasting I mean smelling. What about the new stick kind? Thanks guys. :biggrin:
  43. Cyrus

    I Love the smell of burning tire in the morning, insane

    http://www.dumpalink.com/media/1132567542/Import_Drifting_Video Let it keep playing, this guys driving with one hand and one foot! Look how they are counter steering in the direction they want to turn!
  44. Ivan Seeking

    Medical Can dogs accurately detect cancer in humans through smell?

  45. C

    Medical Smell affects mating, aggression in mice

    http://news.monstersandcritics.com/health/article_1070706.php/Smell_affects_mating_aggression_in_mice Wonder if we are just attracted to certain people cause they smell good and we want to smack others cause they smell bad. :rofl:
  46. E

    Why flowers smell? what's the reason?

    why some of them smell? what's the reason?
  47. Pengwuino

    How to Remove Iodine Smell from Hands?

    Does anyone know how i can get this dang iodine solution smell off my hands. Stupid chemistry!
  48. N

    Medical Baby who is inside a womb can't smell anything

    A baby who is inside a womb can't smell anything outside of the womb right? But they can hear outside of the womb? Or can they smell things (From outside of the womb) inside the womb? Um, would it be possible to stimulate babies inside the womb with visual stimuli and other types of...
  49. JamesU

    Why Do My Feet Smell So Terrible?

    YYYEEECCCHH! My feet smell like crap :yuck:
  50. G

    Why do you need to be able to smell in order to taste?

    I always wondered, why you have to be able to smell in order taste anything. Right now my sinuses are so clogged up from allergies, I can not taste one single thing. Why is this?