I appreciate the answers but find that they generate more questions in the same direction. As of 1998, cloud electrification was still generally termed a mystery. It's difficult to see how small charges over large distances still cooperate to create a lightning bolt as a focused phenomena , either between clouds or sometimes repeating to ground without dissipating the generating cloud. Swirls of air that create the huge charge should push things apart and prevent concentration of charge.and the discharge of huge narrow currents. It's hard to overcome the image of putting a charge into a small cloud chamber filled with smoke or other particles and seeing it all vanish instantly. As for space charges in a vacuum tube, patent 6465965 makes interesting claims about electron screening. If the Edison effect cuts off all current, then it's hard to see how. A traffic jam can slow traffic down but need not stop it altogether. Electrons continuing to boil off should build up to resolve the current flow standoff from filament to plate. I will study the old low plate voltage tubes to see how this fits. The patent asserts that space charge in a tube is a quantum effect of virtual particles setting up a semi-stable cloud of charge. I wonder if any physicists agree?
