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Help in molecule theroy

  1. Feb 3, 2010 #1
    Hi all. I love the fact that you have this forum!
    I need help with a problem of mine that has been lingering in the back of my mind for years. I would like to put it to rest.
    I am a backyard hands on kind a guy with regards to Physics.
    My background is in Mechanical Engineering but I have several pet projects within the Physics realm of influence.

    My question is two part and hopefully simple:

    1. Can you through the use of Electro-magnetism compress molecules? Especially targeting gas molecules.
    2. Would the act of compressing or uncompressing a molecule produce radiation or x-rays?

    I would appreciate any help given.
  2. jcsd
  3. Feb 4, 2010 #2
    1. molecule's vibrational frequencies can be changed by using x-rays (using correct wavelength).
    2. yes...generally when you de-excite a molecule, it emits x-rays or produce phonons.
  4. Feb 4, 2010 #3
    So would it be possible to compress a gas molecule through a series of compression acts? Then later release that compression rapidly? Perhaps I do not know the fundamentals of how molecules work. But would they rapidly expand and produce a thrust effect?
  5. Feb 4, 2010 #4
    Being an aftermath generation of the Star wars/Star trek era, I have always wondered (since high school where I learned the principal operations of a turbine engine) If it was possible to compress the molecular structure of gas partials electro magnetically (possibly acting on charged particles?) and then pass the compressed particles through a plasma beam. (Heating them past the point of magnetic properties) and causing a thrust effect.
    I know these ideas are odd, but please help me put a long time troubled mind at ease.
  6. Feb 4, 2010 #5


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    Unfortunately, this doesn't work. Compressing the molecules is different from (and doesn't help towards) compressing the gas, and what you want to do is the latter.
  7. Feb 4, 2010 #6
    I dont know exactly about compression..but you can study vibrations of atoms/molecules with the help of X-rays. Each vibration has it own energy...i.e. different x-ray energies excite different vibration..But in both the case you dont compress or expand..
  8. Feb 4, 2010 #7


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    I would think that x-rays ionize/dissociate, rather than merely vibrate, a molecule. x-rays are (or at least were originally) defined as EM radiation that originates from electron capture in the inner shells of atoms - thus the electronic structure of the atom is altered. The energy of an x-ray photon is tremendous compared to the bonding energy of a molecule.

    I would assume that the types of photons associated with squeezing and vibrating molecules would be more like microwaves or maybe up to infrared.
  9. Feb 5, 2010 #8

    Claude Bile

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    You can use E-M fields to alter the spatial wavefunction of electronic orbitals (quite routinely in fact). You can extract useful work out of this (for example, through piezoelectricity), but not in gases (at least, not in the way you are alluding to) as the molecules have no fixed orientation.

    You can however, do this in a round-about way through ionising gases, which is stripping the outer electrons (thus "compressing" the atom in the sense of making it smaller).

    No, but ionising gases will generally produce high energy rays.

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