Mind if I chip in? I've worked extensively in both the automotive industry and in the construction industry, arguably the two largest drivers of our economy. As far back as 1976 when I began working in automotive shops there was much confusion in units used. Some bolts were metric sizes and some were SAE, and still are. Every mechanic has to have two sets of wrenches of every type. In construction, only the Corps of Engineers tried (I believe unsuccessfully) to convert to metric. In the automotive industry the change wouldn't be as much an issue, inasmuch as many cars and parts are manufactured overseas using metric units anyway. And once you've tooled-up a plant for metric sizes it isn't a big deal. But in the construction industry the problem is enormous. Imagine the millions of products, specifications and drawing standards that must change. The inertia is staggering. The only progress that I have seen is that standard specifications and manufacturers' data now usually give dimensions, quantities, etc. in both metric and English units. I simply ignore the metric units - NO one I've ever met uses them. Kim -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Dave Gary Sent: Sunday, December 09, 2012 7:03 AM To: Utah Astronomy Subject: [Utah-astronomy] Weights and Measures My last comment on the subject. It has been enjoyable reading everyone's take on this topic. It reminds me of the quandary (at least for them) that Great Britain faced in not converting to the Gregorian calendar. Finally, convenience trumped tradition.hard to do with the Brits. Hey, maybe in another 100 years or so we Americans will see the light in terms of the benefits of the metric system. I'm not holding my breath, however. Dave