First, in my long and somewhat "lack luster" career, I have been engaged in quite a few different "activities", a few of which I thought of as merely a "hobby"; (even though I have never been particularly fond of that word); in one of these activities, you find yourself doing a lot of measuring.
I have always been very interested in geology, which of course, led to reading a lot of books on the subject. When you start reading about geology, you also start hearing a lot about rocks; the more you study rocks, the more you start learning about what rocks are made out of, and of course, many rocks are formed from crystals. Now, unless you're very careful, you will be reading about crystals, and next thing you know, you're "into" crystallography! If you so much as touch one book about crystallography, you're bound to start seeing photographs of gem stones, as almost (but not all) gem stones are "fashioned" from natural (and in some cases, man made) crystals.
A natural crystal, (say, an amethyst crystal), can be fashioned into a gem stone in one of two different ways; some are fashioned into rounded, dome-shaped stones. known as "cabochons", which comes from a French word, and I'm guessing that 90% of the people on A.net know more about French than I do, (which is "very little").
Probably even more gem stones are "faceted", which simply refers to the placement of numerous small, flat surfaces, or "facets", in a particular order, or "cut". When I started seeing pictures of faceted stones, I naturally became very curious as to how this was accomplished; so.......after a lot more reading......I found out; after I found out, naturally, I had to learn to do it; learning to facet entails a lot of different things, but one of them is measuring; you must do a LOT of measuring, and it MUST be extremely "precise" ! Now.........as far as I know, absolutely NO ONE uses the English System of measurement in faceting gem stones; why you ask ? Mainly because, it won't work ! You can do many things using inches and feet, but you won't get far in faceting gem stones with it !
Most gem stones end up in jewelry; say, you want to make a neckless, with a big amethyst as the main stone; unless you're also a goldsmith, (haven't gotten there yet), you're going to need a "mount"; guess what.....all gem stone mounts come in "mm" sizes ! As in 3 mm, 4mm, 9mm, and so on. So, right off the bat, as soon as you start faceting stones, you MUST become familiar with "millimeters", which of course, are part of the metric system ! That was just one of my activities that led me to learn about the metric system.
Another "activity" was astronomy; I got interested in astronomy, then had to learn about telescopes, (which have to do with optics), which led to microscopes, (which are needed to look at gem stones )............anyway, I became very interested in microscopes, and even became curous about electron microscopes. You can imagine my joy, when I ran across this 10 or 12 year old copy of Nat Geo, that had this fabulous article about electron microscopes ! It contained information that was SO useful, So important, some of which I hadn't heard about before, that I spent damn near a week making this chart, a 3ft X 4ft copy of which will hang on my library wall, (just as soon as I can get around to making it.)
I think anyone studying this chart for more than 6 seconds will realize that A. it would be impossible to do all of this with feet and inches, and B. people would laugh at you if you even tried to !
It all starts with the centimeter; ( hell, just study the damned chart ! )
|Some Facts About Electron Microscopes|