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
The observer effect In biology, when researchers want to observe animals in their natural habitat, it is paramount that they find a way to do so without disturbing those animals. Otherwise, the behavior they see is unlikely to be natural, because most animals (including humans) change their behavior when they are being observed. Farnam Street fs.blog The Spoken and the Unspoken uxethnography