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Subatomic particles: Comparative sizes

  1. Nov 19, 2009 #1

    Now that my book is finished, I’ve been toying with an idea for an animation I’m thinking of doing. One of the things I want to show is the real comparative sizes of subatomic particles (including strings) and how much empty space there is at the atomic and subatomic levels. People don’t have a good understanding of this – in fact, most representations have given people the wrong idea. I do not want numbers. Numbers are great but they do not give a layperson any kind of feel for size especially with atoms wrongly being represented as compact objects in textbooks and elsewhere. So, I’ve been researching this angle and what I’ve come up with so far is:

    • If an atom were the size of our solar system, a string would be the size of a tree (perhaps this depends on which theory? If so I want the smallest and the average).
    • If an atom were a mile in diameter it’s nucleus would be the size of a marble. Actually, I found several comparisons that all seem a little different. Like…
    • Imagine the atom as the size of a professional baseball stadium (in 3D). The size of the nucleus would be about the size of a baseball in proportion. Ants would be far too big to represent as the electrons.
    • That an atom is 99.9999% empty space.

    I’d like any consensus on the above that I can get.

    What I don’t yet have is how the size of a quark fits into all this. I understand that this one is not so easy but I need something. Anyone?

    I assume that in most string theories (if not all) that ALL particles are based on strings and that a string's vibration determines what type of quark or Leptons or other particle (gluons) you get (is this correct?). So it sounds like one string per quark or Lepton, therefore 3 strings per hadron.

    As always, any help is greatly appreciated!
  2. jcsd
  3. Nov 19, 2009 #2


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    Gold Member


    This will help:

    http://pdg.lbl.gov/2009/tables/contents_tables.html" [Broken]

    The official source.

    I also found this from 2005, HyperPhysics, Georgia State University:

    http://hyperphysics.phy-astr.gsu.edu/hbasees/hframe.html" [Broken]

    Using the index feature you can find masses, etc for all elementary particles, this may be simpler, easier to use than the Particle Data Group.

    Good luck.
    Last edited by a moderator: May 4, 2017
  4. Nov 21, 2009 #3

    Awesome links! Thanks!
    Last edited by a moderator: May 4, 2017
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