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Question about vibrational quality of a molecule (like Deuterium Oxide) ?

  1. Oct 27, 2012 #1
    I cant seem to find an answer to this.

    The question is: If I obtained Deuterium oxide from lets say a plant that manufactured it in some part of the world, and then obtained Deuterium from another plant manufactured from some other place in the world, is it possible for them to have different vibrational qualities?

    If not, can you please explain to my in terms of physics why not?
     
  2. jcsd
  3. Oct 27, 2012 #2

    Bobbywhy

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    Will you please explain what you mean by "different vibrational qualities"?

    This will assist those who would attempt to respond to your question by making clear exactly what your meaning is. Thank you.
     
  4. Oct 27, 2012 #3
    I mean vibrational frequencies of the molecules.

    Some research students (non physics) wanted to see if its possible to have 2 samples of deuterium oxide, each with a different vibrational quality. The point is that the deuterium oxide molecules will vibrate differently, so when fed to something like a fly, because the vibration in the molecule is different, it will react with the receptor differently. (maybe the receptor accepts molecules based on its vibration)

    Does that make any sense what so ever?

    I thought it would be impossible to have different vibrational qualities of something like deuterium?
     
  5. Oct 27, 2012 #4

    russ_watters

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    I've never heard of a property of matter called "vibrational quality", so I'd say the answer to most of the questions is no.

    Also, what's "the receptor"?

    Sorry, but this all sounds like gibberish/technobabble to me.
     
  6. Oct 27, 2012 #5
    Hey I don't disagree with you! This is why I came here.

    They want to do a test regarding quantum biology. So, they thought if they had 2 samples of deuterium, and fed it to an insect or animal, that its membrane or cell receptors might be affected in terms of vibrational frequency of the deuterium molecules.

    Can you possible tell me how I can explain to them that you cant have 2 samples of the same composition, like Deuterium Oxide, and have their molecules vibrate at different frequencies?

    Example of receptor: If you drink water, and drink heavy water, its obvious that heavy water taste much different. So, the heavy water molecules react differently with the taste receptors.

     
    Last edited: Oct 27, 2012
  7. Oct 27, 2012 #6

    russ_watters

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    Why would you think that?
     
  8. Oct 27, 2012 #7
    They told me that Heavy water tastes different than normal water.

    So, since the taste is different, would it not mean that the taste receptors activated differently with heavy water compared to normal water?

    Can you explain how the vibration frequency of the molecules of Deuterium oxide HAVE to be the same as any other sample of Deuterium oxide?
     
  9. Oct 27, 2012 #8

    mfb

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    Similar to hydrogen, oxygen has several isotopes, too. D2O can differ in the isotopic composition of oxygen. You always have the same types of molecules in your water, but the relative numbers of molecules can change.
    As a molecule, D2O has well-defined vibration and rotation states and corresponding energies. The influence of the oxygen mass is small (as it is heavy compared to the hydrogen anyway).

    BUT: You won't see that in liquid (or solid) water. The interactions between the molecules are too strong to give sharp peaks. And a lot of water vapour is probably bad for animals, independent of the molecular spectrum.

    Source? And why do you think it is "obvious"?
    Concerning the taste of heavy water could not find any difference at humans (but it seems that rats can smell it).
    The viscosity is a bit different.
     
  10. Oct 27, 2012 #9
    I am sorry, I did not really mean to say its obvious. But, I thought (I am not that educated in biology) if something taste different, then it comes down to the taste receptors taking in the molecules of what is being tasted.

    So, are you saying that vibration and rotation states of D20 will be the same in all samples that are D20?

    So, would the vibration and rotation states of D20 differ from diluting it?

     
  11. Oct 27, 2012 #10

    Drakkith

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    If the isotopes of the hydrogen and oxygen making up the D2O are all the same, then they are identical and there will be no difference in any of their states. Since Deuterium is a specific isotope of hydrogen, the only difference could be the isotope of the oxygen atom. If this is the same as all others in your sample then they are all identical.
     
  12. Oct 27, 2012 #11

    mfb

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    The available states: Yes.

    Or smell receptors. They have a large influence on the taste. And things like viscosity, temperature, mechanical properties and so on are not related to specific taste receptors.

    No, you just add more lines to the spectrum*. Again, this is relevant for vapour only.

    *well, I would guess that you always have some H2O and HDO in the sample anyway, so those lines are not completely new.
     
  13. Oct 27, 2012 #12
    Ok great, all great info!

    To sum up, how can I explain to them that no matter where they get the D20 from (plants, countries, etc), it will have the same vibration and rotation states?

    Also, if I have 2 samples of the SAME D20, is there any way to change how it acts quantumly? I honestly think this is what they are trying to figure out, something to do with quantum biology. They want to feed some D20 to insects, and give them different samples of D20, and see if quantum changes in the D20 will have an affect at the receptor site.
     
  14. Oct 27, 2012 #13

    Drakkith

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    Simple. They are all identical. Identical molecules have identical states.

    I don't think there is such a thing as "quantum changes". This is really difficult to explain if you don't know much about quantum mechanics.
    But anyways, given the same circumstances, identical particles will act identically, down to a certain uncertainty that is inherent at the subatomic scale.
     
  15. Oct 27, 2012 #14
    Great, thanks!

    I know a little bit about quantum theory (more on a personal hobby level), as I have not got to that point in my degree yet.

    I would love to be able to explain to them briefly in terms of quantum mechanics why identical particles will act identically at the subatomic level and quantum level.

    Can you think of a way that you could do something like I explained (Feeding insects D20 or anything and recording their activity levels, as D20 affects their inner clock), and try to explain any changes on a quantum level?

    EDIT: Would it be possible to give a insect d2o in a normal environment, then give another insect D2O in a environment of higher electric field and notice a difference? Would the electric field matter at all? Could it possibly interfere with the insect brains electric field?

     
  16. Oct 27, 2012 #15

    russ_watters

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    Who are these biology students and who are you to them? I think they might be messing with your head, because it looks like they are feeding you gibberish.
    Don't. Just tell them they are talking gibberish.
    No. Heavy water is not electrically charged.
     
  17. Oct 27, 2012 #16

    Drakkith

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    The first part would be to understand what the differences are between D2O and H2O. For example D2O has stronger bonds and different bond lengths than H2O thanks to the difference in mass of the hydrogen isotopes. http://en.wikipedia.org/wiki/Deuterium#Physical_properties

    But I am slightly confused as to what you mean by explaining things as the "quantum level". Explaining energy bonds and lengths and such is a normal procedure in chemistry, is it not? That seems to me to be the "quantum level".

    I can't say for certain, but I would expect there to be negligible effect, at least until the electric field is so high that you have problem generating and sustaining it without arcing and shorting and such. (Which would be very dangerous to your insects)
     
  18. Oct 27, 2012 #17
    Thank you everyone for all the help!
     
  19. Oct 28, 2012 #18

    mfb

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    "Identical" is the point here. There is no way to label those molecules as "This is molecule 1, that is molecule 2". You cannot distinguish between them.
     
  20. Oct 28, 2012 #19
    Guys!... I found this research. I think this is what they were talking about.

    However, can someone confirm by quickly reading this here. http://warmingsystem.blogspot.ca/2011/03/fruit-flies-smell-deuterium.html

    All it suggests is that flies can detect the vibrational qualities of D20 compared to H20 correct?! and not vibrational differences between D20 (which we all have established is impossible because all D20 will have same vibrational differences because its THE SAME compound/molecule! )

    Thanks everyone for the great help and information!
     
  21. Oct 28, 2012 #20

    mfb

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    I cannot see any hint that some vibrations are relevant. Fruit flies can notice the difference between H2O and D2O in the air, and they need some genes which are relevant for smelling to do so. In addition, they can distinguish between H2O and nitriles in some undescribed way. That is all you can conclude based on the description in the blog post.
     
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