Is it a fiction that electrons and quarks have no spatial extent?

It's always puzzled me how objects with properties like rest mass and charge (and color) could really be geometric points. Is this just a fiction needed for the math to work? Could quantum field theory work with spherical electrons and quarks?

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Possible duplicates: physics.stackexchange.com/q/41676/2451 and links therein. – Qmechanic Jan 18 '13 at 22:02

You are quite right about the standard model. Beyond the SM the experimental situation is that we know that if the electron has any internal structure then the energy it takes to excite this internal structure is greater than any of the labs have been able to manage. We can easily rule out structures at scales of $\sim 100\ \mathrm{GeV}$, which equates to a distance of roughly $10^{-18}\ \mathrm{m}$. For specific models you can probably get even better limits. The PDG has reviews on this pdglive.lbl.gov/… – Michael Brown Jan 18 '13 at 6:33