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Is the Atom proven?

  1. Jun 30, 2011 #1
    Seems like a simple questions just got into a little bit of a debate, and need some clarification.

    Is the Atom and its particles proven?
  2. jcsd
  3. Jun 30, 2011 #2


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    Define proven.
  4. Jun 30, 2011 #3


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    Put it this way, as far as scientific debate goes, there hasn't been any since around 1910, and the publication of Perrin's book http://www.archive.org/details/atomsjean00perrrich" [Broken] gives the beautiful summary: The same number (within error), determined in 13 different ways, many of which are totally independent of each other.

    Of course, today we've both got much more accurate values for the number, but also hundreds of new reasons. We can 'see' individual atoms on a metal surface using an STM microscope. We determine the locations of atoms within crystals all the time in crystallography.
    Last edited by a moderator: May 5, 2017
  5. Jun 30, 2011 #4
    I would say the conceptual idea of an atom and as a unit as per alxm has used it yes proven and atoms exist.

    What an atom actually looks like as in the old school interpretation of an electron particle spinning around the nucleus group of partciles which we used animate like a mini solar system ... well no that story is under definite cloud literally and figuratively by Quantum Mechanics (QM).

    I presume the later part is which you are referring to and no that is far from settled.

    Take for example the humble electron under classic atom theory it was described as having a size described as http://en.wikipedia.org/wiki/Classical_electron_radius.

    In QM the electron becomes a point partcile which is a sort of oxymoron if you think about it (http://en.wikipedia.org/wiki/Point_particle) but the only way to define it.

    So the answer I guess depends on why you are asking the question.
  6. Jul 1, 2011 #5
  7. Jul 1, 2011 #6
    I think it might mean anything that results in making life easier.
    Atoms are proven to exist because with our models of atoms we can make airplanes fly, computers and other stuff.
  8. Jul 1, 2011 #7


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    I suppose by 'literally' you mean the frequent references to the electronic density distribution around an atom as a 'cloud' (which is still a metaphor), but what do you mean by 'figuratively'? What property of electrons in atoms is not explained by quantum mechanics? There does not exist any experimental results at all there which haven't been predicted by quantum mechanics, within experimental and theoretical errors.

    You might want to read carefully the wiki page you linked to for point particles, which explains: "This should not be confused with the classical electron radius, which, despite the name, is unrelated to the actual size of an electron." and that the current theoretical and experimental consensus is indeed that electrons have no volume.

    There's no contradiction here. The classical electron radius is neither an actual radius of the electron, nor a classical (as opposed to quantum-mechanical) concept, as you seem to imply. Electrons were described as point charges even in classical physics. (e.g. the Bohr model) Nor is 'point particle' an oxymoron - the term 'particle' in physics does not imply volume. On the contrary, it usually refers to an object where the volume (should it have one) is either irrelevant or negligible.
  9. Jul 1, 2011 #8
    Like 'air' is proven. Yup.
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