RPG as Group Exercise

A roleplaying game (or RPG, for short) is part noémprovisational theater, part storytelling, and part game. A single person (the gamemaster) runs the game for a group of players that pretend to be characters in a fictitious world. The world could be a mystery game set in the 1920s that takes you adventuring around the globe, a fantasy realm inhabited by dragons and trolls and sword-wielding barbarians, or a science fiction setting with aliens and spaceships and world-crushing weaponry. The pl...

 Back-of-the-Envelope Calculation

It was from Kuiper that I first got a feeling for what is called a back-of-the-envelope calculation: a possible explanation to a problem occurs to you, you pull out an old envelope, appeal to your knowledge of fundamental physics, scribble a few approximate equations on the envelope, substitute in likely numerical values, and see if your answer comes anywhere near explaining your problem. If not, you look for a different explanation. It cut through nonsense like a knife through butter.