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 Top Idea in Your Mind An Essay by Paul Graham paulgraham.com I think most people have one top idea in their mind at any given time. That's the idea their thoughts will drift toward when they're allowed to drift freely. And this idea will thus tend to get all the benefit of that type of thinking, while others are starved of it. Which means it's a disaster to let the wrong idea become the top one in your mind. ideas