GlennR

How many cubic inches are the engines in your cars?

Mine are 2.0l and 2.5l.

livedarklions

I'm trying to think of any recipe I've ever used that referred to ounces as a measure of weight other than maybe referring to a __ ounce package of __, or the size of the cut of meat or fish. Correct me if I'm wrong, but I think the vast majority of people in the U.S. don't use kitchen scales at all.

Phil_gretz

So, I just asked my wife and we nearly got into a screaming match because I couldn't get her to answer the question simply. She kept saying that I was an idiot, and should just use common sense. Sigh. She then pulled out a recipe that showed that ounces of liquid are always volume, and may be expressed by the next highest unit (1 cup). Solids, like feta cheese or frozen spinach, are measured in ounces, which are always weight. She uses a scale. 8 ounces of fluid = 1 cup, volume. 8 ounces of cheese = solid, weight it. 8 ounce steak? Weight it.

livedarklions

8 oz. steak? Get a bigger steak.

Thomas15

Yes, Consumer items are one thing. The US military and aerospace industries are still as you point out imperial SAE and there are no efforts being made to change that.


So for example, Boeing aircraft, commercial and military regardless of the customer and what country they are operating in, are buying hardware in imperial dimensions. Countries that buy military hardware from US suppliers or overseas suppliers manufacturing by license are using SAE as well and even joint projects such as the international space station where US parts are used they are in imperial.


I have 35 years in the component level manufacturing military/aerospace industry and have seen metric spec prints maybe 3 times in all that time. When the US Airforce puts an explosive device from an F-18 right smack dab in the middle of the 3rd window from the left on the southwest corner on the 42nd floor of a building 25 miles away, the missile is dimensioned in imperial, units, launch from an airframe dimensioned in imperial units and targeted by instruments built in imperial units however there may be a software conversion to metric to keep our allies happy. My gut tells me things will stay this way for as long as there is world wide market demand for this kind of stuff that the US makes.

SethAZ 

We're definitely schizophrenic about our units. I can't dispute what you said in the rest of your comment about components being dimensioned in imperial units, but on the ground, in use, the metric system is used. Distances for road marches, map coordinates, shooting distances, etc. are all done in metric. On the other hand, speedometers will still show speed in mph. It's quite the hodgepodge. A soldier might tell you the maximum effective range of his weapon system in meters, the weapon system itself will usually have its caliber indicated in metric (40mm, 60mm, 81mm, 120mm mortars, 155mm arty, 5.56mm or 7.62mm small arms, though we have the .50 cal (1/2") too because it's been around forever). He'll then pack his 35 lb. ruck and go on a 12km ruck march, etc. Then he'll form up for the ramp brief before a vehicle movement and be told the max speed is 50mph and catch-up speed is 60mph or whatever. It's all a huge mashup.

In temperatures I struggle with Celsius. I know -40 C and -40 F are the same, that water freezes at 0 C, boils at 100 C, and that "room temperature" is about 26 C. I know that in the 40s it's hot, but I still can't relate to 43 C the same as I can relate to 109 F. I haven't got the same "feel" for celsius temps that I have for fahrenheit.

Units are strange beasts, and it's my pet theory that units should always be something that a human being can relate to using small numbers, since we only have so many fingers and toes hehe.

When I hand-load ammunition my loading tables, component weights, etc. are measured in grains. There are 7000 grains to a pound. Sounds like a crazy unit to still be use, but it actually makes a lot of sense, since it results in small but whole numbers that are easily comprehended. A typical 5.56mm round might use a 69 grain bullet and be loaded with 23 to 25 grains of powder. Those are useful, relatable numbers. Our European friends will measure their reloading components in grams. Makes sense since it's metric, right? No. 25 grains of powder is 1.61997 grams. That's a really crappy unit to use, because very meaningful differences are expressed not in the whole part of that number, but in the decimal places. The difference between 24 grains of powder and 25 grains of powder is very significant, yet it's 1.55517 grams to 1.61997 grams, and that difference in ~.06 grams just isn't as relatable or comprehensible to a normal person doing normal things. Handloaders will try to measure powder and drop loads accurate to .1 grains, but that distinction is getting into the thousandth decimal place when measuring in grams. It's just a nonsensical unit to use for this. Same reason, but less exaggerated, why we don't measure terrestrial distances in parsecs. Who could relate to a speed limit sign that showed .000000000000000941693 parsecs/second?

I won't bore you (anymore than I probably already have) explaining how helpless I felt on a trip to Italy back in the 80s trying to figure out whether I was getting a good deal or not when the exchange rate from Lira to US Dollars was something like 3400: 1. Hmm, 97000 Lira. Um, is that a lot?

downtube42

​​​The very simplicity of the metric system is as you go up and down in units, the conversion factor is always a multiple of ten, so you do it easily. You wouldn't say 1.61 or 1.54 grams, you'd use milligrams, the numbers are 161 and 154, the difference is a very reasonable 6. In the imperial system, moving up and down between inches and fractions and feet and yards and miles is a royal pain. 172 inches is how many feet? Don't know, so you just stick with inches, and yes pretty soon you get stupid numbers like 749 inches or 1/32nd.

OTOH all the mental gymnastics required for the imperial system might fend off mental decline - I can do base 12 and base 3 in my head, and am decent at figuring out half or twice measurements with fractions. Figuring half of 15 7/8 is better practice than figuring half of 48. It's just seven and a half which is eight sixteenths plus seven more sixteenths for seven and, uh, fifteen sixteenths. Right? Rather than half of 48 is 24. I feel smarter already.

SethAZ 

Yeah, well except for temperatures, where I struggle, I can operate pretty well in both systems. I've got nearly as good a feel for distances in meters or km, or measurements of small items in mm or cm as I do in inches, and I concede the base 12 stuff is kind of ridiculous compared to base 10. Fortunately a meter is just a yard plus three inches, give or take, so it's close enough. And km are close enough to miles that figuring that fudge factor quickly isn't that hard.

We might think that measuring things in 1/8 or 1/16 is ridiculous, but that evolves from the ease of dividing things in half. Nobody will struggle to cut 7/8 of a cake, because you just cut it in half, cut those halves in half, cut those halves in half, then take 7 of them. There's no easy way for someone to reasonably accurately cut you 7/10ths of a cake. So some unit bases came about due to simple practicality. We lose sight of that growing up with computers doing the decimal math easily. It's no accident that we evolved mathematics around the base 10 system and just happen to have 10 fingers on our hands. Some coincidence eh?

There's a reason back in Ebenezer Scrooge's day that specialist mathematicians like Bob Crachitt were employed to count and calculate the finances, because there were 20 shillings to the pound, and 12 pence to the shilling, for 240 pence to the pound. That required decimal math for the pounds place, base 20 for the shillings, and base 12 for the pence. That wasn't the kind of thing just anyone on the street could do complex calculations on.

scott967

Fortunately on the seas where we don't have grids we fire our 5 inch guns at targets at 15k yards while steaming at 10 nautical miles / hour (kts). (1 nautical mile = 1 minute of arc on the earth) more or less 2020 yards (always use 2000 as the conversion factor), Now with GPS it isn't so much an issue. Standard maneuvering distance was 1000 or 500 yds depending.

scott s.
.

Kapusta

I am unclear from your post whether Europeans use grains or metric. But the reasons you are giving are not the way these things work.

Fist of all, they would likely be using milligrams, not grams. SO that .06 gram difference you mention is more likely going to be called 60 milligrams, which is actually quite relatable.

But second, and more important, you need to mind the significant digits, here. Those numbers you are throwing out there in grains are rounded to two significant digits. specifying 25 grains is different from specifying 25.0000 grains. When you say "23 to 25 grains", your euro counterparts are not saying "1.49037 to 1.61997 grams". They are not even saying "1490.37 to 1619.97 mg". They are either saying "1.5 - 1.6 g" or (more likely) "1,500 - 1,600 mg".

And that 0.1 grain accuracy? That's 65 mg. So realistically, someone using metric to measure to a similar accuracy as the guy measuring to the nearest 0.1 grains is going to measure to the closest 50mg. Easy enough.

Many medications are dosed in mg, and many are in the range you are talking about.

Kapusta

Yep! Math would work a lot better if we had either 4 or 6 fingers on each hand.

jbell_64

302...

SethAZ 

I've never spoken to a European handloader to ask him how he measures his powder, but the reloading data I find from European countries always lists their recommended powder charges in grams.

Here's an example of 9mm loading data from VihtaVuori Oy, a Finnish handloading components manufacturer. This one helpfully also lists their recommended charges in grains for us US folks (not all the data you find does). Notice that they aren't listed in milligrams but grams. That one loading with N320 powder is 4.8 grains or 0,31 grams. They're both two significant digits, so the difference isn't huge here, but I think human nature is to be more comfortable dealing with whole multiples of something, not finely divided fractions of something else. I think that human nature really requires that units result in small numbers for things, and whole number multiples of things, for best comprehension. The further you get from whole numbers into more and more decimal places, the harder it is for average humans to conceptualize it. That's why the "kilo" and "mili" and so forth prefixes are used, too: to transform a unit that's inconvenient to use for a particular thing into something that's more convenient to use.

I'm actually fairly comfortable with both metric and imperial for most things, other than my admitted shakiness around temperatures. To swing this back to the OP topic, there's a difference between the challenge inherent in a 100-mile ride as compared to a 100-km ride, so it's not surprising that some imperial unit users who feel proud of their century ride accomplishments might get irked to have someone else use the same word for a lesser accomplishment. Then the randonneurs show up and scoff at the century (100-mile) rider's distance accomplishments, and finally some Tour de France rider reminds us all that they did more than these distances every day for three weeks straight. Since it seems to be human nature for folks to compare themselves to others, I'd bet there are plenty of marathon runners who scoff at folks putting those 1/2 marathon stickers up on their cars, too.

The only times I've personally referred to a "metric century" in real use were when a friend of mine and I were going for a long ride and jokingly decided to make it a metric century so we could make it sound grand. I mean, there's no special name otherwise for a 62.something mile ride, and we like to feel as grand as anyone else, so why not?

GlennR

Ford calls it a 5.0

jbell_64

my f150 doesn't have that badge, and neither did my bronco LOL. Last truck was a 318 though.

GlennR

jbell_64

that is a boat load of badges! Glad my 2013 doesn't have all that stuck to it. I even had the stx decals removed.

desconhecido 

Trick question: what about butter?

Phil_gretz

As a sous chef, I know the answer to this. Always volume, even if its to be liquified. The typical measure is Tablespoons, unless you're Paula Deen. For her, butter is measured by the pound.

Bill in VA

In fact my 1997 Ford Ranger truck is all-metric for the drive-train (engine/trans), and many of the major body bolts while SAE are usually in an SAE size with a Class B fit metric equivalent. It has a 4.0L engine. Tell a mechanic what the CI is if they ask what size, and you get a blank stare. That was made 23 years ago.

livedarklions

Is that true for commercial bakers?