0 Replies Latest reply on May 22, 2014 8:30 AM by Mitsuru Yamada

    Infinitely small, small and small question.  Does an electron have spatial extension?

    Mitsuru Yamada

      I am asking you a question:  how large is the radius of an electron?  Though most of us cannot prove, we are compelled to believe that it has a spin.  Here I would like to quote from a book "Quantum man" written by Lawrence M. Krauss.


      "...electrons possess a property called spin because they carry with them intrinsic "angular momentum", the property extended objects possess if they are spinning.  Classically no such concept exists for a point particle, which cannot behave as if it is spinning because there is no "center" (that is, another point) to spin around.  In order to have angular momentum, like a spinning bicycle wheel, for example, classical; objects must have spatial extension." (page 100, lines 6-14)


      Does the radius of an electron have finite value still, or is it definitely zero?  Which is true?