connecting a large network of these vacuum tubes so that the switches control each other allow you to run mathematical calculation and even construct• Modern electronics have moved beyond power-hungry vacuum tubes, and now exploit domain of properties of semiconductor materials: thermionic valve rectifiers are replaced by solid state diodes, and the voltage controllable behavior of the triode is reproduced by the silicon transistor. The monolith to miniaturisation that is a smartphone in my pocket contains trillions of transistors each of them functionally identical to a warmly glowing tube fully-programmable electronic computers