Somebody asked questions about why America.. whoa here we go.. was too stupid to adapt the metric system like Europe. Well the obvious conventional wisdom is that we're stupid and have bad habits. But let's think about that for a moment.

Let's start with a yard. Not your yard, a yardstick. But your yard could be measured with a yardstick just as easily as it could be measured with a meter stick. Why? Because we know what a yard is and we know what a meter is and we know arithmetic.

Let's say your yard is rather large, like mine. It would then be 50 feet by 40 feet = 2000 square feet. Now there's something very nice about feet that we know, because feet divide into 12 inches. 12 is a special number because you can easily divide it in halves, thirds and quarters, and that is what you generally do with land. Yards are conveniently 3 feet. 36 can be divided very nicely too. But when you look at 360, then you get something that's rather strikingly brilliant.

360 can be divided by 2,3,4,5,6,8,9,10,12,15,18 and 20. That's rather clever don't you think? You can't do that with decimals so easily, and after all the point of any system is not that things can be measured. We could invent meters and re-invent them to be any arbitrary length and do the arithmetic. The strength of the metric system lies in its ability to scale by orders of magnitude. But scaling by orders of magnitude is not something that happens very often in the human scale. In engineering, sure, but not in home construction, food recipes, human body measurement or any other of a dozen activities (hmm dozen) that we are regularly involved in. Now we could go into all of the ways we measure all of the things we do from miles per hour to paper sizes, but that long long discussion actually gets to the heart of Metric vs Imperial. In short, however, this is all about **fractions**. Or if you like to be mathematical about it, it's about superior highly composite numbers.

Now a friend told me that there are two kinds of engineers in the world. The kind that have put a man on the moon, and the kind that use the metric system. (ooh burn!) The picture above is taken from his machine shop. It sounds like braggadocio until you listen for another minute. Then the man says 'SAE'. Now anybody who's turned a wrench in their lives knows something about SAE sockets vs Metric sockets. But if you look at what SAE actually was and is, things get very interesting.

Check out this dude Kettering. I don't know about you, but to me that's a career full of wowsers. 186 patents is no accident. He helped build GM into the world's largest company. But what's fascinating, as when I listen enough, is to learn how many parts in the world's market for parts are of SAE measure rather than of metric. I often think in terms of meters nowadays, but only for things that are linear. I will always think of pies when I have to divide, and I will think of fractions. But isn't it interesting, just looking at the picture, which is a better, simpler, faster way to measure?

Maybe the metric system is why we haven't put another man on the moon.

Now I'm going to show the other side here, because what we've done in America which is metric to the bone before just about every other nation is in our currency. More than just about anything, currency lies in the realm of Extremistan. Orders of magnitude are quite proper here. But at the small level of the ordinary consumer, we don't do much with pricing that accords to common 360 sense.

For example. In old money there were 12 pence to the shilling. That would be quite nice if you purchased many things by the dozen. If a dozen eggs cost a shilling, a half dozen eggs would be sixpence. A smart shopkeeper would try to price such things that way for the convenience of his customers. Then again, one might be a bit too clever (by half?) using the same system to obfuscate, as bakers may have throwing in for their extra sized dozen. We certainly don't price things logically at the farmer's market level, but clearly decimal pricing lets us see unit prices reflect economies of scale in bulk pricing. So for things that scale orders of magnitude, decimal is better.

By the way, what time is it?

No matter how you cut it, measurements are irregular and none can conform to a single rule...much like languages or certainly parts thereof. There are 365.25 days in a rotation of the sun by the earth. not a number easily divisible by 10 which is the decimal system in a nutshell. Good luck with arranging a calendar of 100 days, or weeks of 10 days.

I work in my engine building hobby hobby with both decimal systems and imperial. There is also decimal imperial as opposed to fractional. Both make sense. Imperial is more organic.. surely all the rage these days.

However you are forgetting one area that metric does quite nicely.

1 cubic meter of fresh water at sea level is 1000 KG or 1 metric ton (or more properly, a tonne). Volume to Mass.

Yeah, I know the old phrase "a pint's a pound the world around", but doing engineering, the type where three digits is enough (and four too many, and five is WAY out), the mass to volume above makes for easy rules of thumb. Yeah, you do the math afterwards, but the metric equivalence above is very useful. I deal... well used to... deal in sea ships, coal, cars, and containers. The "pint is a pound" really isn't helpful there. Mind you, everything is still in TEU, or Twenty-foot Equivalent Units, but they do have metric standards.

And don't get me started on baking. Metric and by weight, thank you very much.

So I must cordially disagree. I remain in favor, outside of time and navigation issues, the metric system.