Thanks to all who commented on my previous writing. It seems I should have clarified the term "pure" SI. Before I do that, let me stress that SI a coherent system. That makes it distinct from all previous, metric or medieval or earlier systems. It is a dream come true to all who deal with measurements and numerical values in a broad range of disciplines..
The "pure" implies the use of numerals for numerical values (not words) symbols for prefixes (not words), symbols for units (not words), and the application of the rules for writing. SI is intended to be a universal language of symbols written the same way by everybody everywhere. As we know, most of the symbols look like letters to us but that is not the case with the majority of mankind. Let's be grateful for the European origin of the symbols and think of the other peoples before complaining of any difficulty. Think of the Chinese, who, I am told by people that go there on business, have mastered and use pure SI. Here is a simple demo of one of the many advantages of symbols. I just read a scientific paper full of spelled out units such as <megawatt-hours per year per kilometr-squared>. If written instead in symbols, such as MWh/yr/km2, the paper would be shorter by a page or two. Resorting to SI that unit is simply W/m2. Now THAT would shorten the paper. And improve readability. Both would contribute to more people likely reading the work. Writes often claim that API rules prohibit symbols. Well, not everywhere. Our Metric Today needn't be concerned. I hope that the future electronic version of MT will reflect "pure" SI. As to the inability of the general public accepting SI - the public will learn anything that is seen/heard often enough. All we need to do is use it, be consistent, and the practice will spread. I would like to think that children everywhere in the world are now taught the few ubiquitous, "common life" SI symbols and rules, and that teachers do not receive their certificate without showing fluency in this truly international language. Stan Jakuba
