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What are senses?

  1. Oct 16, 2007 #1
    All our eyes do is sense light and its variation in the form of color...then what is color?(there was a theory suggested that just like there are animals that see things in black and white manner....we might be limited to how we percieve matter too!)

    Our nose smells....if someone had to make an electronic nose...how would distinguish diff. types of smell? How does our nose work?(as eyes pick up light)

    Our toungue creates sound by vibration. What is sound? If it exist...then how do we not now that our body is limited to 5 senses and there might be thousands of senses we don't sense...what will we call that then?

    Our ear distinguish sound into disturbing and relaxing manner as other senses do. How do they interpret this? For example...why do our toungue like one taste and not like another?

    Skin: What is touch? It can determine the level of friction, temperatue, pain, pressure, what else? How can it? How does it work?(not biologically)

    6th sense: is there any scientific evidence on it at all? Even it is not proven, is there any shocking experiment conducted?(like there have been ghost photos) Would that be known as telekinetic power? How does that work?

    7th sense: third eye: ability to see where you are not. Is there any scientific date on this?

    Other senses: Did I miss any? Name anything man...doesn't have to scientifically proven...just has to be a theory in work.(like string theory...but not as validated ofcourse)
    Last edited by a moderator: Oct 16, 2007
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  3. Oct 16, 2007 #2
    What evidence convinced you that some animals cannot distinguish colours that we can, while also leaving you uncertain about the surpassability of our own sight? (Heard of sea animals that can see polarisation, hawkeye?)

    You don't realise that the nose and tongue basically detect chemicals, that "electronic noses" do exist (eg. are frequently used in airports), and that your voice is no more a sense than it is produced by your tongue?

    Why don't you google how the inner ears works? It's basically a spectral analyser..

    As for touch, you want it explained *without* reference to skin and biology? You mean you want a psuedo-scientific "explanation"?

    The rest of your post (imaginary senses with less validation than string theory) isn't really worth responding to at all.
  4. Oct 16, 2007 #3
    Whether an animal can sense colors is dependant on whether the retina of the animals eye is covered with both rods & cones. It is the cones which detect color. Whether animals have cones I don't know. Perhaps it depends on the species. I hear that dogs only have rods and are therefore color blind.

  5. Oct 16, 2007 #4

    Math Is Hard

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    Note: moved from General Physics to Biology. -MIH
  6. Oct 16, 2007 #5

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    Your eyes don't create color for you, that happens later, in the visual areas of your brain. You have cone receptors in the retina that are reponsive to different wavelengths of light and when they are stimulated, they pass that information along to areas that can interpret it and, ultimately, result in a sensation.
    Not all animals see in black and white, many have limited color ranges (compared to humans), but some can even sense light ranges outside of human perceptual limits. Some snakes detect infrared waves, for example, and some bees can detect ultraviolet wavelengths.
    As with your eyes, you have receptors in your nose that are stimulated by things in the enviroment. While the receptors in the eye are responsive to light (they "capture photons"), the receptors in your nose respond to chemical samples "captured" through the air.
    Sound is created when receptors in your ears respond to pressure waves travelling thorugh a medium, usually air, but I believe you can also hear a little bit when these waves travel through water.

    As far as other senses that exist for humans, we don't have 100% certainty that there aren't any others, but we have managed to write down the ones that we have observed over and over and over again, and we are reasonably certain that these are the basic ones that are possessed by the general, non-impaired population.
    Some of this is personal preference shaped by familiarity, some of these preferences came about as an evolutionary advantage. For instance, we recoil from bitter tastes because they are often poisonous.
    Like the other senses, you have receptors (and nerve endings, in the case of pain) that are specifically tuned for these different types of information. As far as "not biologically", I wouldn't have a clue how to answer that.
    Debatable at best, and if I knew how that worked, I'd be asking for a Nobel prize!
    See "Sixth sense" above.
    There is also proprioception, which is basically the perception of one's body orientation in space.
    Last edited: Oct 17, 2007
  7. Oct 17, 2007 #6


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    "The sixth sense" is a nickname given to various types of ExtraSensoryPerception, and as the name implies, it isn't real. But there certainly are more than 5 senses and what you would call the "sixth" or "seventh" is just a matter of which others you would think of to list first. Perhaps your sense of balance would be listed sixth and your sense of body position seventh. Doesn't matter, though.

    There are also many, many unconscious "senses" or feedback control mechanisms. Your conscious sense of body temperature (different from the touch sense of temperature) is linked to unconscious senses and controls of blood vessel dilation, hair folicle tensing, sweat output, etc. Your body has detection mechanisms for finding disease and cuts and bruises that have nothing to do with your sense of touch (pain). If you include these, you could probably say we have hundreds of "senses".
  8. Oct 17, 2007 #7

    Ivan Seeking

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    The question was properly posed as to whether or not we have any scientific evidence for any so called sixth sense.

    The correct answer is, no; though I personally think some forms of blindsight might qualify.
    Last edited: Oct 17, 2007
  9. Oct 17, 2007 #8


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    The way it was worded, with a sixth sense being one thing and a seventh being another, implied to me the OP thought the names referred to single, specific senses.
  10. Oct 17, 2007 #9
    This was recently covered in another post, but here goes again. Most neurologists/neurophysiologists/? are quite sure there are many more senses than 5. The obvious ones are linear acceleration and angular acceleration (both in the inner ear). There is also proprioception (orientation of your body parts), though a few will argue that is an internal sense and doesn't count.

    In vision, there are also edge detector cells that are specific for vertical lines, or horizontal lines, and so on.

    You can obviously sense temperature.

    Reductionists, of whom I am generally one, will say that we can decide whether something is a sense by asking whether we would require a specific sensor if we were building a machine version of ourselves. We will count somewhere near 20, though I'm seen one researcher claim 34! (I think he went overboard, but who knows).

    The American Academy of Neurology maintains an excellent website, open to the public, at
    You can search on senses and come up with a lot of information, some of it conflicting (it is an active science, after all).
    Do not use Wikipedia; it is sadly out of date.
  11. Oct 17, 2007 #10
    "Sound is created when receptors in your ears respond to pressure waves travelling thorugh a medium, usually air, but I believe you can also hear a little bit when these waves travel through water."

    So does a high pitch sound travels faster than lower pitch? What is the difference btw the sound created by a violin and a sound that is created by the guitar? Since they are both vibration...why do they sound different?

    How does our tongue distinguish btw diff. kinds of taste?

    Alright, you can tell me how touch works biologically.

    What I meant by more senses is that I was talking about a certain type of senses I guess.(only external ones) The ones by which we view reality. Eyes view radiation(limited to photons), Nose views chemical reactions.(to certain extent-wouldn't this also be in the category of radiation since the definition is: energy that is radiated or transmitted in the form of rays or waves or particles)

    Ear: view vibration, wouldn't this also be a form of radiation since it comes in a form of wave?

    Isnt everything radiation?(since everything is a wave-according to a theory)
  12. Oct 17, 2007 #11
    You asked a question. I answered it, giving you a well-respected set of sources. Is there a point here? The one to two dozen senses are well-known in the scientific world and are well-documented. Is there a direction I can point you in? What exactly do you want to know?
  13. Oct 17, 2007 #12


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    Pitch is pitch, Skhandelwal: Frequency. A higher pitched sound sounds higher pitched because it is higher pitched! Physically, it makes those little receptors vibrate back and forth faster.

    All sound travels at the speed of sound.

    And no, not everything is radiation (it is tough to even find meaning in that question). Sound waves and light are two entirely different animals. And other senses don't have anything to do with either.

    I agree that your line of questioning seems redunant....
    Last edited: Oct 17, 2007
  14. Oct 17, 2007 #13
    Sorry, I'll try to be more clear.

    What is radiation then?

    How does our ear tell the different btw a sound created by guitar and a sound created by violin?

    Why do all sounds travel at the same speed?

    I am sorry, this sounds really silly...I tried searching too...but what is frequency? I really used to know well.(not from the view points of receptors, but from viewpoint of the toungue...creating the frequency)
  15. Oct 18, 2007 #14


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    Because they travel in the same médium: air.

    A sixth sense is perhaps magnetic?

    2007 Jan 5;144(1):356-67. Epub 2006 Oct 25.
    Evidence of a nonlinear human magnetic sense.

    Carrubba S, Frilot C 2nd, Chesson AL Jr, Marino AA.

    Department of Orthopedic Surgery, Louisiana State University Health Sciences Center, P.O. Box 33932, 1501 Kings Highway, Shreveport, LA 71130-3932, USA.

    Human subjects respond to low-intensity electric and magnetic fields. If the ability to do so were a form of sensory transduction, one would expect that fields could trigger evoked potentials, as do other sensory stimuli. We tested this hypothesis by examining electroencephalograms from 17 subjects for the presence of evoked potentials caused by the onset and by the offset of 2 G, 60 Hz (a field strength comparable to that in the general environment). Both linear (time averaging) and nonlinear (recurrence analysis) methods of data analysis were employed to permit an assessment of the dynamical nature of the stimulus/response relationship. Using the method of recurrence analysis, magnetosensory evoked potentials (MEPs) in the signals from occipital derivations were found in 16 of the subjects (P<0.05 for each subject). The potentials occurred 109-454 ms after stimulus application, depending on the subject, and were triggered by onset of the field, offset of the field, or both. Using the method of time averaging, no MEPs were detected. MEPs in the signals from the central and parietal electrodes were found in most subjects using recurrence analysis, but no MEPs were detected using time averaging. The occurrence of MEPs in response to a weak magnetic field suggested the existence of a human magnetic sense. In distinction to the evoked potentials ordinarily studied, MEPs were nonlinearly related to the stimulus as evidenced by the need to employ a nonlinear method to detect the responses.

    PMID: 17069982 [PubMed - in process]
  16. Oct 18, 2007 #15
    I think this works on the same theology as dejavu. Something had occured in your lifetime similar to event but is not stored in your 'main memory' but rather in your
    sub-conscious memory until it is activated by a similar or reoccurance of the event.
  17. Oct 18, 2007 #16
    Thanks for the good reference; that was informative.
  18. Nov 7, 2007 #17
    I have no evidence at all, only the vague recollection of an article I read about humans having telepathic thoughts that can link our brains. I'm pretty sure the article was debunking this myth and actually saying that human brains can analyze each other subconsciously, i.e. we can pick up on small facial twitches and body language without realizing it. This 'people sense' can be learned, but some people have a natural affinity towards it, have you ever met someone who seemed to understand how you feel? Basically they're very good body-language readers, and can also identify your feelings through what you say. American Tv has shows like Law and Order where some good examples of interrogators reading people and causing them to react certain ways. We all have the ability to read one another, you can tell someone is dangerous if they come at you with a knife trying to kill you...
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