  We show that the electron in the Riemann-Cartan spacetime with extra
dimensions has a finite size that is much larger than the experimental upper
limit on its radius. Thus the Arkani-Hamed-Dimopoulos-Dvali and Randall-Sundrum
models of the weak/Planck hierarchy in particle physics are not viable if spin
produces torsion according to the Einstein-Cartan theory of gravity.
