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Body response to EM

  1. Jul 3, 2003 #1
    why do our body dont feel the EM waves.
     
  2. jcsd
  3. Jul 3, 2003 #2
    you're asking a loaded question. our bodies do feel some waveleangths of EM waves. such as radiated heat (or infarred). and have you ever focused light through a magifying glass on to your skin? you're feeling light there too.
     
  4. Jul 4, 2003 #3
    ya when concentrated light falls on the skil we feel it.

    i have asked this question to some of my friends but all explained with u r answer "light ". my point is can we feel the microwave (ie not in the form of heat) but like antennas do. it may feel so odd but still i have dought that how do antenna (Al-alum)fell the microwave any my not our body. we call it so sensitive but y it dont fell the EM in the air.


    [?]
     
  5. Jul 4, 2003 #4
    Shankar - Learn how to properly convey your message in the language of this forum.
     
  6. Jul 4, 2003 #5

    language ??

    u can understand my problen right.
     
  7. Jul 4, 2003 #6
    We can feel curtain EM waves because its more of an evolutionary factor really. If we recieve to much EM waves in the form of radiated heat it will have a harmful effect on us such as burns and the destruction of your body. While other EM waves are not as potent to you, therefore, we don't necessarily need to feel them.
     
  8. Jul 16, 2003 #7
    'feel' means percievable by one out of our five senses.

    smelling EM waves is certainly out because the olfactory sensors usually respond to only things that have mass.

    tasting EM waves is also out for similar reasons

    hearing them is out because the pressure fluctuations they generate in the atmosphere by photonic collisions with the atoms is extremely low to be 'heard'

    seeing is in but due to evolutionary reasons our sight is sensitive to only certain spectra (yes,I am referring to wein's law and sun being 5000 K though some people DO have objections to the reason behind this selective sensitivity).

    now comes the most vast and touchy sense: the touch.

    we feel that someone is touching us only if there is some local deformation of our skin or some chemical reactions(say due to heat) are triggered.Only those photons are responsible for such chemical reactions whose energy matches the vibrational/rotational of the molecules of our skin and infrared does the best.Higher frequency EM like x-rays do not excite the atoms genrally, it ionizes it(still another chemical reaction though).
    Microwaves have smaller energy per quanta,but large exposure may be dangerous.Anyway,percieving it is not possible(though you may percieve its hazards :wink:) .
     
  9. Jul 16, 2003 #8
    http://www.physiol.ucl.ac.uk/research/turin_l/chemical_senses_complete.pdf

    A spectroscopic mechanism for primary olfactory reception

    Abstract

    A novel theory of primary olfactory reception is described. It proposes that olfactory receptors respond not to the shape of the molecules but to their vibrations. It differs from previous vibrational theories (Dyson, Wright) in providing a detailed and plausible mechanism for biological transduction of molecular vibrations: inelastic electron tunnelling. Elements of the tunnelling spectroscope are identified in putative olfactory receptor and their associated G-protein. Means of calculating electon tunnelling spectra of odorant molecules are described. Several examples are given of correlations between tunnelling spectrum and odour in structurally unrelated molecules. As predicted, molecules of very similar shape but differing in vibrations smell different. The most striking instance is that of pure acetophenone and its fully deuterated analogue acetophenone-d8, which smell different despite being identical in structure. This fact cannot, it seems, be explained by structure-based theories of odour. The evidence presented here suggests instead that olfaction, like colour vision and hearing, is a spectral sense.
     
  10. Jul 16, 2003 #9
    thanks for the inetresting article.
    But I am wondering whether this applies to excitation by EM waves.
    Consider this and dont shy from bullying me if i am wrong :wink: :

    The article says that the smell is a function of vibrational spectra and not structure but this vibration spectra pertains to the molecules of the object we are smelling and EM waves are not some sort of molecule.Yes,there is spectra of EM waves but the analogy ends there.When we say that microvaves and infrared have different frequencies we do not mean that they vibrate in different ways(whatever that means).

    But still one idea the article does suggests is this:

    Suppose the molecules of a object (say, wine) responds to different frequencies of EM in different vibrational modes.Then the wine will smell different in different kinds of EM waves that surrounds it at some particular instant.Sounds cool
     
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