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Some questions

  1. Sep 27, 2008 #1
    is it possible to make something 0 kelvin?

    and if you did this would it make that particle or group of particles have no motion or kinetic energy?

    do particles naturally want to move or is that influenced by thermodynamics (heat)?

    if photons cause light and they are described as an elementary particle than how can they travel through matter, isnt that like a particle going through another particle?

    is sound just a movement of particles in a wave pattern and is therefore caused by kinetic energy?

    when we smell are we actually just inhaling particles or do particles release specific energy that causes odour?

    is it possible using massive heat to separate an atom into just elementary particles?

    is it possible to manipulate elementary particles sort of like how we can with atoms to build other structures or is that considered futuristic?

    I know its a lot of questions im just interested in physics and have some weird questions about it but thanks in advance to any helpful replies.
    Last edited: Sep 27, 2008
  2. jcsd
  3. Sep 27, 2008 #2


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    It would probably make sense to post these as separate questions, but lets have a go at answering some.

    No, it's a stastical thing, as you get to lower temperatures it get harder and harder to extract that last bit of energy. It's like getting allthe toothpaste out of a tube. The record is something like a few billionths of a degrre.

    Classically yes, althought some substances can behave very strangley as you get near 0K. Look up superlfuids.

    Particles (and everything else) naturally want to carry on moving as they were - either in a straight line or stopped unless you make them do something else. TO make particles bounce around you need to keep putting in energy.

    Photons are particles of light. They aren't matter - they are purely lumps of energy. They don't actually travel though a material like glass, they are absorbed by one atom and re-emitted in the same direction, they are then absorbed by the next atom and re-emitted again. It is possible for small particles to go straight through a lot of matter just because they are very small and atoms have a lot of space between them. Neutrinos go straight through a planet without many being absorbed.

    Sound is movement of particles passing on a little bit of energy to the next particle.

    It's a chemical process, little bits of the chemical get into the air and are absorbed onto special receptors in your nose. They make chemical changes which trigger nerve cells and send an electrical signal to your brain.
    Last edited: Sep 27, 2008
  4. Sep 27, 2008 #3
    sorry for the many questions next time ill separate them but if particles want to constantly move in a straight line why doesnt everything just keep moving or is it because of the four forces of our universe that help to constraint this movement so that we can actually have structures of things and we don't just float apart.

    And as a part of the photon question i read that it is a quantum particle and therefore exhibits the particle-wave duality so if it isnt matter than how can it be a particle? and what do u mean by a lump of energy is this a specific kind of energy or something. I mean I understand that light is like a wave and that waves properties like its wavelength define it on the spectrum allowing us to decide if its visible infrared or gamma and all that. So what I am asking is a wave physical like a particle or is it a weird kind of phenomena.
  5. Sep 27, 2008 #4


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    Yes, molecules are held together by the electrical attraction between positively charged nuclea and negatively charged electrons. But if you gave an particle (on it's onw in space) a push it would carry on in a straight line until it hit something, or was attracted by another charged object.

    Particle is a loose term. A photon isn't matter but is a particle in that it's a discrete lump of energy. The big breakthrough in QM is that everything is a wave, a golfball has a wavelength - it's just that the heavier the object the smaller the wavelength so it is only noticeable for light (with no mass) or very small subatomic particles.

    Light is electromagnetic radiation/energy. A photon is the name of a small lump of electromagnetic energy.

    The wavelength or frequency of a photon is related to it's energy.
    As I said everything is a wave, but it's probably easiest to picture a photon as a little packet of a wave - this isn't really true, but there's no obvious way to imagine it.
  6. Sep 27, 2008 #5
    This isn't my gig, but negative temperatures are mainsteam physics. I don't know if zero is included.


    [mentor's note: further discussion of negative temperatures has been moved to this thread so as not to derail this one.]
    Last edited by a moderator: Sep 28, 2008
  7. Sep 28, 2008 #6
    thanks for these answers, there really helpful. So when imagining a wave of something in our world which is 3d would it be like taking the traditional 2d wave and throwing 1 more through the middle of that wave that was turned on its side.
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