A very recent breakthroug in solving the problems of the missing viscosity in accretion discs and why the quasars are the most powerful sources of light in the universe has been achieved in the group of Prof. T. Mishonov and announced on the astrophysical section of the arXiv.org e-Print archive, astro-ph/0507696

T. Mishonov and diploma student Y. Maneva, in collaboration with T. Hristov from The Johns Hopkins University, Baltimore, have calculated the heating power and stress tensor for shear flow of turbulent magnetized plasma in the framework of Langevin-Burgers approach to the turbulency and derived an explicit formula for the effective viscosity. They show that the effective viscosity is formally divergent for evanescent bare plasma viscosity. This characteristic feature of the result solves the problem of the missing viscosity in accretion discs and reveals why the quasars are the most powerful sources of light in the universe. The formulae for the heating and stress tensor can be incorporated in global models for accretion discs and also in all other physical conditions where there is shear flow in magnetized turbulent plasma.