Thermalization of starlight by elongated grains - Could the microwave background have been produced by stars

The possibility of the microwave background being produced by stars after the big bang is considered. The critical problem for this hypothesis is the source of the long-wavelength opacity for observed wavelengths greater than 10 cm. It is shown that free-free opacity cannot thermalize the background. Spherical dust grains also fail, but needle-shaped conducting grains can provide sufficient opacity to produce the observed spectrum with a metal abundance Z approximately equal to 10 to the -7th.