Safety cut rope axe man In the first nuclear reactor, constructed by Enrico Fermi in 1942 under the bleachers of the University of Chicago football stadium, the control rods were held up by a manila rope. A man with an axe was told to cut the rope if the reactor got out of hand. This "safety cut rope axe man" is supposedly the origin of the term SCRAM for an emergency shutdown procedure. Brian Hayes, Infrastructure: A Guide to the Industrial Landscape wordsacronymsenergy
Whereof one cannot speak My propositions are elucidatory in this way: he who understands me finally recognizes them as senseless, when he has climbed out through them, on them, over them. (He must, so to speak, throw away the ladder, after he has climbed up on it.) He must surmount these propositions; then he sees the world rightly. Whereof one cannot speak, thereof one must be silent. Ludwig Wittgenstein, Tractatus Logico-Philosophicus What can be put into words meaning