Ciro Santilli @cirosantilli 37

Basically the same remarks as for university, just 10 times more useless, see also: Section "Motivation".

The bane of multicellularity.

Ideally can be thought of as a one-way ticket gate that only lets electrons go in one direction with zero resistance! Real devices do have imperfections however, so there is some resistance.

First they were made out of vacuum tubes, but later semiconductor diodes were invented and became much more widespread.