Yes, because dividing things in 12 parts (12 inches to the foot), or 16 (16 ounces to the pound), or 3 (3 feet to the yard), or complete nonsense (5280 feet in a mile) is really weird. And it is not as if it depends on what you are measuring… Length measurements are all over the place!
And, yes, metric keeps Babilonian craziness with the 60-seconds-to-the-minute and the 60-minutes-to-the-hour stuff – but what in metric is the exception, for American customary units is the rule.
Is it so hard to stick to (mostly) a single scale factor across the board?
It’s all a long-standing conspiracy to keep the plebs confused and consolidate real power where it belongs, with the ultimate goal of bringing about the end of the world through applied numerology.
BTW this has been covered above, but minutes and hours are no less “metric” than inches and such because they all trace back to reproducible standards. The international standard unit of time is the second.
OK, Flyer, since you claim to understand the American system: Suppose you have a fish tank, that’s 18 inches wide, 48 inches long, and 24 inches tall. How many gallons will it hold? Can you figure it out even with a calculator? Because given the equivalent metric problem, I can do it in my head.
I’ve got a recipe that calls for a tablespoon of something. But that recipe is for three servings, and I’m making it for 50. I don’t want to measure out sixteen tablespoons; that’s obviously a better job for a measuring cup. So, how many cups do I need?
If I tell you the torque of an engine in foot-pounds and its RPM, can you tell me its horsepower? Because if you tell me the torque in newton-meters and the rotation speed in radians per second, I can easily tell you the wattage.
Which weighs more, a pound of feathers or a pound of gold? Which masses more, a kilogram of feathers or a kilogram of gold?
I don’t think the 1970 date is correct. I remember as a kid that large size soda bottles were 64 oz (and glass). That’s a lot later than 1970. I suspect you’re about 10 years off on that.
My (vague) recollection is that at some point there was a big push to convert entirely to the metric system. A lot of talk about it, with attendant pushback. I would speculate that soda manufacturers simply got out in front of the curve and were left there when the anticipated shift never came off.
As stated above A pound of feathers and a pound of gold both have 0.45359237 kg of Mass, and both weight a pound. As a 1 pound-force is one 1 pound under Standard Gravity (SI unit).
Every measurement system has benefits and disadvantages and while SI is typically nicer in a modern world it does have issues.
But how you are self selecting special use cases that try to stack the deck for the SI units how about some alternatives.
If you want to fly from the Equator to the 45th parallel, how many kilometers is that? I know that it is 2700 NM. (1 min is 1 NM)
You have a recipe that Calls for 1 KG of flour and you want to cut it by 1/3, 1/8 and 1/16, without rounding write the recipe and find it on your measuring cup.
12, 16, and 5280 were choice for reasons that are far more practical with historical methods of math.
As an example 5280 can be evenly divided by every single digit except for 7 and 9. And 16 is evenly divisible by those digits more than 10 is.
While we may find base 10 nicer overall, the numbers they chose are not random.
A shout-out to base-12 and base-60 for anything commonly divided into parts.
“hmm, in this foot-long space I can fit 2 6-inch shelves, 3 4-inch shelves, 4 3-inch shelves.”
“How many miles-per-hour am I going? Let’s see, it’s easy if I can do a single mile in 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 10, 12, 15, 20, 30.”
And I know that it’s 5000 km (from the Equator to the pole is 10,000 km)
That’s easy, 1/3 kg, 1/8 kg, and 1/16 kg, and why am I looking on my measuring cup instead of on my scale?
And those reasons are only practical for the precise uses for which they were designed, which in many cases are now obsolete. Why do I care how far a mule can pull a plow before he gets tired? Because that’s the reason for the furlong, eight of which are defined as a mile.
OK, I realized that I grew up in a town that mined a material that is used in glass making (trona) and decided to call up someone who worked as a sales rep to the bottling companies.
While still anecdote the explanation makes more sense than anything I have seen so far.
Around ~1967 Both Pepsi and Coke release Aluminium versions of their 12 once can which had pull tabs and which were “high tech”
At the same time period the Metric movement was gaining steam around the world, including in the US and Canada, and the equipment to make plastic bottles was expensive.
Previous to that point the 12oz Pepsi and 10/12oz Coke (king size) bottles. Pepsi’s was larger to compete with Coke and Coke had two sizes that the bottlers could chose based on their local market needs.
Coke had a “family-size” bottles 26oz which was 4 * their older 6.5oz normal sized bottle.
When Pepsi-co created a new “Family Size” PET bottle around 1970 they simply made it the large enough to provide a similar quantity of soda as in a 6 pack of 12oz cans.
12oz ~= 355ml
355 ml * 6 = 2130ml = 2.13 liters which they rounded down to 2 liters.
As the popularity of the “two-liter” grew as a term in the US 1 liter bottles were introduced to leverage that popularity while also simplifying sales of the enclosures, or the same molds for the enclosures to our neighbors in the north if the opportunity was there.
TLDR; 2L is a good approximation of a six-pack of 12oz cans in a “bulk” container. And was sensitive to the world wide changes in standards of measure at the time.
Note: As I said, this is anecdote from a retired salesman from a competing industry, but it seems to fit.
Yeah, it’s a mess and we kind of like it that way. I think that in a little while, we Yanks will get more used to hearing international reports with elevations and distances given in meters. Eventually we’ll figure out that a 5k race is really 5 kilometers, and that the sky has not fallen down much for that being so.
100k is the distance that can decently driven in an hour at (moderate) highway speed.
Oh, the previous schtick about a pound of feathers versus a pound of gold is a trick question based on the sort of pedantic fact that gold was/is weighed by the troy ounce and feathers would ordinarily be weighed by the avoirdupois ounce. See Troy weight - Wikipedia for the many details. So 16 av. ounces (= 1 av. pound) of feathers in fact weighs more than 12 troy ounces (= 1 troy pound) of gold.
Using a calculator, it’s 89.8 US gallons. I suppose I could have done it in my head, but dividing by 231 would be a bit of a bother.
One cup plus two teaspoons. This one is very easy in the US customary system, because its volume measurements are mostly a binary system. There’s two tablespoons in a fluid ounce and 8 fluid ounces in a cup. Since you chose a problem with a 16 multiplier, it came out very easy. (The two teaspoons comes from the extra 2/3 tablespoon. There’s three teaspoons in a tablespoon.)
Troy weight, and the troy ounce is a special system of measurements that BTW is used by every country using International System of Units (SI) outside of East Asia.
(abbreviated “oz” or “ozt”) equals 31.1034768 grams exactly
The fact that it still exists is not the fault of either the US customary measurements or international avoirdupois pound which is legally defined as exactly 0.45359237 kilograms.
Apothecaries or Troy units of measure are industry specific and not even defined off of the US/Imperial or avoirdupois pound, but off of the SI system.
1 ozt = 31.1034768 grams exactly, and thus 1 International/US/Imperial pound = 1 International/US/Imperial pound of anything else
To date the only gold coinage minted in the SI system are China’s Gold Pandas so there is not claim of superiority for the rest of the world there.
But in very common fields like navigation, machining and other fields the avoirdupois and customary units are used due to practicality.
And BTW, how are you measuring those “masses” on a scale? Are you correcting for the offset from local vs standard gravity? To you have a watt balance? What about use cases where substances are hydrophilic, and the weight can very but the volume is more accurate for your needs? As a fan of physics how do you dismiss the existence of a rational biased measurement system that is directly defined off the same basis units as SI while you use amu, kWh, eV or Torr?
Can we cook our food in Celsius? which is a non-SI unit or do we bake your bred in K to be SI compliant? Do we use Newtons to weight our flower, or do we use the verboten kilopond, which is analogous to the pound-force? Are you suggesting that we just ignore that distinction and use “kilogram” in an improper way while debasing other?
While some industry (like gold) use units of measure which are purely historical, others like navigation use them due to the failings of the SI units.
Are you arguing that they just ignore finite number of numbers when written as a decimal, and accept that compounding errors are just the random result of us being born with 10 fingers?
The same accessibility that the metric system gives for non-experts in some areas induces serious impediments in other cases for the same non-experts.
It is a good system and I tend to prefer SI units, but I would never try to do precision machining or ocean navigation with it, as there are systems that are far more useful.
And if you have to have a scale to use the metric system do segment you can easily attach another scale to those same systems, they are all derived exactly off the same chunk of metal in a vault in France.
But really your argument really doesn’t invalidate my claims, it just demonstrates that people/industries that use odd units of measure like Troy need to avoid using the more common abbreviations. And in the case of your post it is more correct to use the suffix “lb t” or “lb troy”
Leaving aside the weight of gold or feathers, you must lead a very interesting and challenging life if those are the kind of calculations you need to do in your head every day. And what measurement units do you use for calculating how many seconds in a metric hour?
There’s a difference between shoppers and people who happen to be buying things… and shoppers are never confused by units of measure and are never unsure which is the best buy.
As far as supermarkets are concerned, every market I go to puts the unit price right on their labels - if you can read and care to actually look at the price tags, they tell you outright which is the best deal regardless of what’s written on the packaging. The 30 piece “economy” stack of Dixie plates is 9 cents per plate, the 10 piece stack of Brand X plates is 8 cents per plate - if you’re literate, you have no excuse for being confused about which is the best deal.
As for “pencil and paper” to calculate things, what a silly thing to say. Normal people use the calculator on their phone.
The only people who have problems are idiots who are sleepwalking though life anyway - to anyone with a couple of functioning brain cells, it’s all a non-issue.
Medical stuff is the US is usually metric, except when it is not…
meds are mostly in mg, liquids in ml (not cc!) height in cm, weight in kg.
Except that catheter sizes are in French and needle sizes in gauge, to name a few.
Craziness, I say!
Yes, most grocery stores list unit prices. But have you ever actually paid attention to them? Often, three competing products will have their unit prices listed as per ounce on one, per gram on another, and per package on the third.
rat avatar, are you seriously saying that the fact that you have to round numbers to a finite number of decimal places is a flaw of the metric system? That has nothing to do with the metric system; everything that humans ever have to do with numbers always involves rounding to a finite number of decimal places.
Musicat, I obviously don’t do all of those calculations every day. But I do some of them sometimes. Some days, I don’t have to do any unit calculations at all, and some days, I do calculations which would be equally easy in either system. But I have never once in my life encountered a calculation which would be easier in the American system than in metric.
First, Consumable goods (with few exemptions like beer )in the US have required BOTH to be listed on the packaging, Fair Packaging and Labeling Act requires this and it went into effect on February 14, 1994.
Second, humans haven’t always used the decimal system so I would ask for a cite on that. This is General questions, and I was not aware that Arabic numerals were even used in Europe for all time. But yes, there are lots use cases where the compounding loss in precision caused by strict requirements of a base 10 decimal based system would be a problem and where maintaining rational representations result in far lower error.
Rounding multiple times or representation errors accumulate, and it is impractical to use guard digits for all use cases. Guard digits also have a problem of implying a precision that doesn’t exist, so not only do you have to track long strings of zeros, you also have to more closely track the loss in precision.
Sometimes it is advantageous to have multiple methods particularly when they are all derived from the same basis units, which is exactly what all NIST units are, as they have exact SI definitions.
But lets be clear, in base 10, division and loss of precision is a 40% chance, with 1 irrational (7) and three repeating (3,6,9). Compare this to Dozenal that has a 25% chance (7,9,11). but that is a whole other ball of wax.
While there have always been limits on precision, we are talking about losses due to convention here. This loss is not due to the limitations of math, in fact they can be avoided with rational numbers by keeping them rational until the last operations.
But I am willing to change my mind so feel free to provide cites.
I know this part is from the ancient zombie section, but it’s so cute I just had to quote it!
Apparently humans are born with an “instinctive” understanding of how far a mile is, built in to our DNA. Say “mile” to a newborn baby, and it will stare at you in instinctive comprehension (if you say it in just the right way it will giggle). Whereas those confusing Europeans and everybody else has to scratch their heads and memorize math stuff to figure out things like how many meters there are in a kilometer.
