As one of our trade’s more accessible “experts,” I am happy to field questions from the general public, too. This week one of the more unusual calls was from a lecturer in a completely unrelated field who was concerned that his gear metaphors might not be technically accurate. It made me think of a favorite Star Trek-Next Generation episode where the Enterprise encountered a planet where the inhabitants only spoke in metaphors. The Federation adventurers had great difficulty understanding the aliens because their universal translators apparently had no “metaphor setting.” Talking about gears to an audience of “civilians” requires careful consideration of what is truly “general knowledge” and what is “confusing jargon.” I was very surprised to hear that my caller thought his audience not only understood his use of a geartrain to describe the system of relationship, but often phrased their follow-up questions in the gear terms. He was worried that he might be carrying the analogy too far so he called me to talk about his “model” and the claims he was making for it. I expressed my worries that his model might over-simplify some relationships, but suspect he went away happy that his lecture passed an “expert test” without needing major revision. I guess the “Spacely Sprockets” and “Cogswell Cogs” references in the old Jetson cartoons really stuck with people. Or perhaps this is a case like misheard song lyrics where people think they understand what is being said when further investigation would show just how far off they are. A case in point: Overdrive is an automotive term for a speed increasing device that allows the engine to run at less revolutions-per-minute than the drive axle in order to save fuel. When you have engaged “overdrive” you are actually reducing energy consumption and not working as hard. Yet in popular song the understanding of “overdrive” is exactly the opposite — i.e., that “overdrive” is a short-term boost in effort. Once the poets and songwriters put their erroneous spin on a word we are probably stuck with it. As the saying goes “given a choice between truth and legend, print the legend.” Here at Gear Technology we take the contrary path and stick to peer-reviewed truth. What mangled metaphors irritate your hearing?