Also skin (for tannery) is measured in square foots, or it was twenty years ago. Perhaps UK controls the commerce here too?

It’s like the Australian farm woman who complained that her hens were laying smaller eggs ever since the country adopted the metric system.

Michael Duff mentioned the case of a woman who was asked by a TV interviewer if she believes in Global Warming. She said: ”If you ask me, it’s all this changing from Fahrenheit to Centigrade that’s causing it”.

Then there is the triplets of tonne (metric tonne), short ton and the long ton.

Wonder whether the short ton (2,000 lbs) is an American invention that attempts to maintain a semblance of going Metric!

And then there is Shimano, who produces bicycle parts that don’t conform to anyone’s unit system and for which one needs a new tool each time there is a new line of parts!

Some here might be amused at space mission teleconferences during the mission’s instrument construction and integration phase, if those missions involve instruments and spacecraft built in different countries. There are detailed discussions of nuts, bolts, screws and their tools. Sometimes these screws and tools items are given to the other teams (with the appropriate paperwork and if it doesn’t involve ITAR).

One good example of task specificity came up in the IEEE magazine. Why are capacitors denominated in microfarads and picofarads, but never in nanofarads? Obviously, microfarad range electronics designers work in microfarads, while picofarad range designers work with picofarads. Need a nanofarad, use a 1,000 picofarad capacitor.

As a fish egg fancier, I always wondered why did the godless (and metric) Soviet Union sold caviar in 14 ounce pounds? Their system of pressure altitudes for high flying aircraft is metric, but different from the Chinese metric pressure altitudes. Of course, low flying planes, up to 18,000 feet measure altitude based on calibrating the altimeter at takeoff using barometric pressure and known elevation, so the aircraft altitude approximates actual altitude over mean sea level. Go over 18,000 feet and its all done with millibars, and calibration be damned. So if you are flying in a small plane and your pilot says you are at 4,000 feet, those feet are not the same as the feet a jet pilot would use when announcing that the plane is at 32,000 feet.

Also, when was the last time you bought produce or meat by the ounce? My supermarket, and just about every other supermarket in these United States, sells by the pound and the hundredth. In other words, the supermarket checkout station designers have imposed a decimal based system on us, and since it was done by a business, not the government, there has been nary a squawk. Try finding a 32 fluid ounce bottle of Coke or 4/5 gallon of Scotch. It’s like gasoline, sold by the gallon and the hundredth.

Designing parts is a lot of hassle. Translating inches to mm and back for every part, hoping that something doesn’t get messed up. Most people have no idea whether 9/64 is greater or lesser than 3/16. They might have some idea what 0.14 is compared to 0.18, though. To compound these problems, most americans are terrible with fractions. I mean, the 1/3 pound burger didn’t survive simply because most people thought it was smaller than quarter-pounder!!!

Ever tried to find the correct allen wrench for a screw? Slightly smaller… Nope, slightly bigger… Maybe it’s metric? Is this metric or is this english? Two sets of wrenches for everything… buying screws just to find they are the wrong size…
A lot of machine parts are made in germany and japan… guess what system they use? etc. etc. Absolute nightmare.

Mr. Machine Shop guy, here’s the drawing – this M5 screw should be 1/4″ from one edge and 78.3 mm from another edge. Use calculator if you want to double check the numbers.

When US Marine Corps started changing their mannuals to fit the metrical sistem, they simply expressed it “1.000 meters from the beach” (you know… a meter and a yard are so near, and a beach is never “straight lined”, so…)

But it’s not true that everything was measured into convenient “dozens or scores” of units. For instance, portable weapons were defined into inches/100 (.30 in rifles, and so on…)

The big problems I see are: 1 – changing all industrial standards (used for centuries, now) to metric system, when the main producers of it are used to Avoirdupois measures; 2 – People around the world are so accostumed to use Avoidupois units, followed by the metric expression (for instance: .30 caliber – 7,62mm; 1″ pipes – 2,56 cm) that it will not change an inch (2,56 cm) in anything…

So if it is left out inadvertently in any force calculation, one will underestimate by about 3.5 times less in the SI units. Some consolation! ”

Well, there is “lb” (pound, unit of mass) and “lbf” (pound-force, unit of force) and one can confuse the two. It is hard to confuse kilograms and Newtons.

elementary charge = e = 4.8E-10 statCoulomb
current = 1 statC/sec = (1/3)E-9 ampere

Potential is statC/cm, which doesn’t grok with me at all. To convert to something familiar: e(SI)/e(cgs)=3.335E-10C and multiply (3.335E-10/(4 pi eps_0) *10^2 (in meter) = 299.7, final units in Volts

bleh

unless you go the cheap option and give everyone bumper sticks which say “km = miles * 1.6″ then that’s a lot of road signs and car speedometers to phase out…

whereas, if it were put the money into say… hybrid research or perhaps new smaller size wheels on bicycles- that would be money well spent!

–
as an aside – for some reason in australia, the metric still hasn’t caught on for heights of people. “oh, he’s about 6ft, is so much easier than 180cm, or 1.8 m”
and I also almost failed a 9th Grade math(s) test when on exchange in the US, as a question on “Convert the following measurements” wasn’t that easy….

m

It will be a long road. Looking at trains, the first standards seem to be signal systems, which is rather more hard to do than conforming road signs. It is slooowwwly coming along.

“And you’re saying Europeans hate us because of our units? That seems pretty superficial to me…”

Dimitry didn’t say hate. But it’s unusual to almost always insist on bipartisan solutions instead of once or twice accept wider solutions. So I believe we think of americans as apart, and not always in a good sense.

“I just don’t think that it’s is feasible (at this point, at least) in practice.”

Eh? Others have done it. If your concern is investment, it will pay off eventually.

“any other application I learned only metric units, with a few exceptions.”

There are quite a few exceptions. Usually in sciences, there fundamental or anthropic values makes more sense, like Planck units or hours instead of kiloseconds. Live and let live, I say.

Well, there was that Mars probe that crashed. Of course, we could balem that on the commie Europeans for using the metric system….

-Rob

So if it is left out inadvertently in any force calculation, one will underestimate by about 3.5 times less in the SI units. Some consolation!

Temperature: To me, Fahrenheit temperatures make a lot of sense for some applications. In the northeastern US, the air temperatures range from 0 (or below) to 100 (or a little above) Fahrenheit. It makes it convenient for me; I judge temperature on a roughly 100-point scale (anything off that scale is either frigidly cold or extremely hot). Outside of that particular belt, of course, the temperature ranges start to look a little more odd. Similarly, body temperatures generally fluctuate about 100 (and the story about 98.6 is one I had heard before, as of course the exact conversion is obvious, but that makes it no less amusing). But for anything outside of these applications (oh, and cooking, but that’s just a function of the dial on my stove), I’d rather use Kelvin anyways. Incidentally, global temperature maps, with the US in Fahrenheit and the rest of the world Celsius, are deeply amusing.

Length: 6 in one hand, half a dozen in the other. In terms of determining height, feet and inches work better for me, but that’s mostly because I don’t have a reference for the same in centimeters. For travel distance, a mile a minute is useful but I’m pretty sure we could adjust to 100 kph. And again, for really big or really small distances my scientific training kicks in and I switch to Angstroms, nanometers, microns, mm, cm, km, AU and variations on parsec.

Weight/mass: I know body weights in pounds, because that’s how I grew up, but I’m surprised that more Americans haven’t subtly started to switch to kilograms (doesn’t sound as big in those units, after all). Similarly, I’m more used to pounds for lifting weights, although I don’t think a change in that would be difficult. In virtually any other application, I use metric units of mass instead of Imperial units of weight.

Area and Volume: Metric all the way. The only exception, perhaps, being gas by the gallon, because that’s how prices are expressed; I could certainly do things the other way with no difficulty. And on a side note, I hate cooking, partially because of the insane units of volume used (Teaspoon? Tablespoon? Can’t we please just switch to ml? But I suppose a lot of secret family recipes would have to be converted…)

And of course, any other application I learned only metric units, with a few exceptions. Pressure comes more naturally to me in psi or atmospheres than MPa and GPa; I’ve seen all of them, but I have less intuition for metric units. I’m also kind of used to barometric pressure in inHg. Oddly, though, I’d rather use large numbers of Pascal to express material strength; go figure. And my thermo class was odd; it was an engineering course, so we had to be able to use both sets of units, even down to having two sets of steam tables in the back of the book. I think they might have even used mixed units in some of the problems, which was just irritating.

I think in time we will switch over, as more people become fluent in both and the advantages of factors of ten become apparent to people who don’t necessarily use scientific notation frequently. This could maybe be enhanced by calling them Imperial units; what red-blooded American wants to be part of an evil empire? Besides Yankees fans, of course.

There will be resistance to a change from the customary system to the metric system, but I think it would take some pretty dedicated individuals to form an insurgency…

And you’re saying Europeans hate us because of our units? That seems pretty superficial to me…

fh—

Perhaps metric units are more convenient, but certainly not if all of your tools (like a mechanic) are built to accomodate another unit system. And they certainly aren’t more convenient if you’ve spent your whole life using somehting different.

I agree that we should probably have the metric system in principle, I just don’t think that it’s is feasible (at this point, at least) in practice.

And I’ve never actually torched anyone’s paper—pre-med students are easy to motivate!