
The Basic Idea of Superstring Theory
Elementary
particles are not mathematical points, as
in conventional quantum theory. Rather, they are onedimensional
loops.
The
characteristic length and mass can be constructed from the fundamental
constants observed in Nature: h, G and c.
Planck length L_{p} = (h G/c^{3})^{1/2}
= 1.6 x 10^{33} cm
Planck mass M_{p} = (h c/G)^{1/2}
= 2.2 x 10^{8} kg
At
energies << M_{p} c^{2}, strings are well approximated
by points, which is why quantum field theory is
so successful.

