IS IT JUSTIFIED TO ASSUME THAT EVERYWHERE IN THE SUNS PHOTOSPHERE-CORONA DOMAIN THE ELECTRIC-CONDUCTIVITY IS HIGH - OR, WHAT DRIVES THE SOLAR UPPER-ATMOSPHERE

For many years, solar scientists have recognized the extreme complexity of the upper solar atmosphere. However, in order to construct a valid theoretical model they have formulated a set of simplified assumptions governing the makeup of the Sun's upper atmosphere. In previous papers (Feldman 1983; Feldman 1993) a number of assumptions used to construct the models were shown not to be valid. In this Paper I bring evidence to question the validity of the last and most important of the assumptions, the assertion that ''Everywhere in the photosphere-corona domain the electric conductivity is HIGH.'' The consequences of the finding are briefly discussed. A laboratory measurement of the electrical conductivity versus temperature in a gas with photospheric composition would resolve this important issue and seem to be feasible.