The magic of marginal electronics

Much of the excitement in both research and practical engineering lies in the exploration of the `margins´, or boundaries and limits, between what is just feasible and what is impossible. Electronics has a particular fascination because, unlike other branches of engineering, its workings are almost invisible, and its power to perform useful tasks is so great as to be almost magical. A good understanding of the fundamental limits of the laws of science and of the rules of thumb or design rules of current technology are needed for the margins of engineering achievement to be pushed forward safely and effectively. The paper contains a personal selection of laws and rules and their application in the fields of radio, control, digital electronics and speculative future communications