The honest answer would be, nobody knows yet. The
current knowledge is that the electron seems to be
a 'point particle' and has refused to show any signs
of internal structure in all measurements. We have
an upper limit on the radius of the electron, set by
experiment, but that's about it. By our current
knowledge, it is an elementary particle with no
internal structure, and thus no 'size'.
Answered by: Yasar Safkan, Ph.D. M.I.T., Software Engineer, Istanbul, Turkey
'A hundred times every day I remind myself that my inner and outer life are based on the labors of other men, living and dead, and that I must exert myself in order to give in the same measure as I have received and am still receiving…'