Imperial versus metric

[Kerbart]

On 1/7/2023 at 4:58 AM, kerbiloid said:

And these containers have different actual sizes, so '40 foot (feet) ' is just a callname based on their historically adopted normative length.

Technically yes, but that's more from a practical standpoint so a 40' fits in a 40' slot without getting stuck. But basically a 40' container is 40', a 20' is 20 foot and a 45' is 45 foot.

[Pthigrivi]

On 1/7/2023 at 3:51 AM, 18Watt said:

One problem I see impeding the conversion to metric is the fact that it (in some cases) is a system designed to be universal, but does not take into account that some measurements 'make more sense' in other units.  It is an arbitrary system of units (aren't they all?), which has been imposed on a variety of industries, regardless of wether it is actually convenient or not.

To be clear, I do think most people (including myself) see an enormous benefit to having a single standardized measurement system.  However, in some cases there is not a clear benefit to using SI units, aside from the standardization issue.  This point is probably going to enrage SI fans, but I ask that you bear with me.  If you truly want the world to convert to your way of thinking, it might be helpful to understand your opponent's point of view.  (And not just insult them..)

I use both Imperial and SI units, and don't really care which units are used, as long as the units are specified.  However, this thread has made me consider which units I have switched over to preferring SI for, and why.

I'll start with baking bread.  I used to use Imperial units, such as cups and tablespoons to measure both dry material and liquid.  However, for dry material (flour, salt, etc.) it makes much more sense to use weight (or mass) to accurately measure.  Grams or kilograms are convenient units to use, equally manageable to ounces or pounds.  I started weighing my dry ingredients in grams (SI).  At that point, it made sense to also measure liquids in SI as well, in mL or L.  For baking, I've been converted.  I use SI.

However, when it comes to cooking I do not find SI units convenient.  I'll use an example of preparing a batch of Hamburger Helper for a family of 4.  A typical meal would use 1 pound (lb.) of hamburger.  One pound is a meal.  How much is that in kg?  0.45 kg.  That's a subtle point, but I'm hoping the SI fans will see the difference.  I need one meal.  I get 1 pound of meat.

Let's take that a step further.  I have two teenagers in the house.  I add 50% to everything.  Now I need 1.5 pounds of meat.  If I was working with SI, I would have to take 150% of 0.45 kg.  Yes, I'm ok with math, I need to add 0.225 kg to my original 0.45 kg.  So now I need 0.675 kg of meat.  But using pounds the math was much easier.  So while I use SI for baking now, I still prefer Imperial for cooking.  And that does indeed bother me somewhat.

Why can't I use SI for all my food preparation?  Well, the answer is, I can!  But it does not necessarily make sense to do so, at least not to me.

In a bizarre world, let's say that somebody decided that for consistency the entire world needed to use Imperial units for everything.  For folks who prefer SI, how would that make you feel, to have Imperial units forced on you?  If everyone used imperial units, there would no longer be issues with consistency, everyone would be using the same units, just like they are with SI.  (Yes, I do understand that Imperial units are in some cases FAR from consistent.).  My point is that I do agree with the concept of a worldwide standard of measurement, which is SI.  However, that does not, in my mind, mean that other measurements are inferior or need to be eliminated.   

Easy peasy we just create a new measurement and numeral system on base 30 with better prime divisors. *sweeps hands together*

[Kerbart]

On 1/7/2023 at 3:51 AM, 18Watt said:

However, when it comes to cooking I do not find SI units convenient.  I'll use an example of preparing a batch of Hamburger Helper for a family of 4.  A typical meal would use 1 pound (lb.) of hamburger.  One pound is a meal.  How much is that in kg?  0.45 kg.  That's a subtle point, but I'm hoping the SI fans will see the difference.  I need one meal.  I get 1 pound of meat.

Let's take that a step further.  I have two teenagers in the house.  I add 50% to everything.  Now I need 1.5 pounds of meat.  If I was working with SI, I would have to take 150% of 0.45 kg.  Yes, I'm ok with math, I need to add 0.225 kg to my original 0.45 kg.  So now I need 0.675 kg of meat.  But using pounds the math was much easier.  So while I use SI for baking now, I still prefer Imperial for cooking.  And that does indeed bother me somewhat.

Where I grew up, half a kilogram was  referred to as a pound, furthermore, 100 gram was referred to as an ounce. Those are great units for cooking and baking, and while not "legal" units, everyone would know what you mean by "a pound of meat" or "2 ounces of licorice." And this is exactly what I meant with "No one thinks it's convenient to ask for a 5.08×10.16 at Home Depot." No, because they won't (it'll be 5×10 instead). That recipe is not going to ask for 454g of meat in a metric cookbook. It's going to be "1/2 kg." Want a meal for 2? Get 1 kg. One and a half time? 750 g. Meal for 3? 1.5 kg. Really, not that hard. Of course if you stick to imperial amounts you'll end up with insane numbers. But I can say the same of imperial. 2 m is a perfect size for a door. But in imperial it's suddenly 6'6 3/4" —those Americans must be mad! Why not use a round number?

"Weird numbers" is a non-argument because in the real world, people will pick nice numbers based on the unit they're using. Metric nuts and bolts for instance are measured in whole mm, and not into weird fractions that translate to round inches (or binary fractions thereof).

[Codraroll]

13 hours ago, K^2 said:

Even if rounding, it's way more precise to round once. What's a third of 1.15kg? Do you round it to 1kg, take a 3rd and call it 300g? But the real answer is closer to 400g. The relative error is now 22% instead of 13% on first rounding.

You round it to 1.2, which is nicely divisible by 3, and get 400 g. That's accurate to within approx. 4% (the right answer is 383.33.. g).

Bit harder to divide 1.15 feet by three, isn't it? Sure, you can do the same exercise and say it's approximately 0.4 feet, but your tape measure isn't likely to feature decimal feet, so then you'd have to convert it to inches, and that's not a whole number. It's 4.8 inches, or four-and-four-fifths if you like fractions. Five if you want to round it to the closest whole number, but that's rounding the wrong way, so it's more like four-and-a-half.

Yet worse if you start bringing other measurements into it. 0.4 of a pound in smaller units, that's not the same number as 0.4 of a foot in smaller units. At least being consistent with base 12 would have been something, but for mass it's base 16 instead. And for volume, a fluid ounce is either 1/10 of an imperial cup, or 1/8 of a US cup, and the two fluid ounces differ by approximately four percent. No logical relation to cubic inches either way, of course, so calculating the volume from length measurements is a hassle and a half. 

Calculating in base 10 and moving the decimal around is a bit easier, I think.

Edited January 9, 2023 by Codraroll

[K^2]

2 minutes ago, Codraroll said:

You round it to 1.2, which is nicely divisible by 3, and get 400 g. That's accurate to within approx. 4% (the right answer is 383.33.. g).

13 hours ago, K^2 said:

Of course, you can work around it with slightly more complex arithmetics, but everything else being the same, having more factors helps make it easier and less error-prone.

[Hannu2]

On 1/7/2023 at 10:51 AM, 18Watt said:

However, when it comes to cooking I do not find SI units convenient.  I'll use an example of preparing a batch of Hamburger Helper for a family of 4.  A typical meal would use 1 pound (lb.) of hamburger.  One pound is a meal.  How much is that in kg?  0.45 kg.  That's a subtle point, but I'm hoping the SI fans will see the difference.  I need one meal.  I get 1 pound of meat.

Let's take that a step further.  I have two teenagers in the house.  I add 50% to everything.  Now I need 1.5 pounds of meat.  If I was working with SI, I would have to take 150% of 0.45 kg.  Yes, I'm ok with math, I need to add 0.225 kg to my original 0.45 kg.  So now I need 0.675 kg of meat.  But using pounds the math was much easier.  So while I use SI for baking now, I still prefer Imperial for cooking.  And that does indeed bother me somewhat.

I understand. But in most case you buy some standard packet of meat. In my country that "normal" 4 person packet is 400 g. Next size is 600 or 700 g depending on meat company, which is practical for larger family. At least I buy very rarely arbitrary amount of food products except fruits and vegetables. Sometimes there are packets in imperial sizes but I count a pound as 500 g. It is also very common to have more complex values because companies have tendency to decrease packets for example 10 % instead of increasing price. After couple of silent decrease they can bring "new larger size" with advertisement campaign and increased price.

 

 

On 1/7/2023 at 10:51 AM, 18Watt said:

In a bizarre world, let's say that somebody decided that for consistency the entire world needed to use Imperial units for everything.  For folks who prefer SI, how would that make you feel, to have Imperial units forced on you?

Probably I could adapt quite easily. I am engineer and used to use and convert imperial units and also some other special unit systems used in certain physics areas in addition to metric units.

[TomKerbal]

I would everyone here kindly suggest to have a look to the NASA flight protocols of the Apollo missions (downloadable at nasa.org). Extremely interesting. Despite from that there are SI units and imperial units in the tables shown in parallel; first for calculating (and for the German rocket engineers probably), second for thinking. And that's what I often observe when working together with colleagues not used to SI units in their ambient. Well, US colleagues are the ones with the hardest dislike by the way I have the feeling ;-)  In hole Asia it's normal for engineers and scientists to use SI and derived units (at least in my project experience).

[Hannu2]

Actually I would be happy if there were global compromise. Units could be imperial but one unit per quantity and decimal notations instead those very impractical rationals. For example an inch would be very practical unit in everyday needs. Most objects I handle have size of 1-10 inch. Kilometer would be 40 kiloinch. Megainch (25.4 km) would be quite practical for everyday traveling purposes. And I have already very used to mils (milli-inch), which is very common unit in electronic engineering.

[kerbiloid]

7 minutes ago, Hannu2 said:

Units could be imperial but one unit per quantity and decimal notations instead those very impractical rationals.

+1!

1 pound = 1 kg
1 ton = 1 tonne = 1000 kg
1 yard = 1 m
1 mile = 1000 m (naut. mile still 1852)
1 foot = 1/4 yard = 25 cm, i.e.a woman foot of ~38 EU.
1 inch = 2.5 cm = 1/10 of ft (which is 25 cm)
1 second = 1  second
1°F = 1K

Spoiler

1 USD = 1 RUR

12 = 10

Edited January 14, 2023 by kerbiloid

[Kerbart]

On 1/7/2023 at 3:51 AM, 18Watt said:

For folks who prefer SI, how would that make you feel, to have Imperial units forced on you?  If everyone used imperial units, there would no longer be issues with consistency, everyone would be using the same units, just like they are with SI.

Welcome to my world, I moved from Europe to the US about twenty years ago (a quite memorable day, I might add).

Some things are easy. Distance and speed are really abstract, meaningless units, so it's easy to adapt to those, 60mph is just as much a value on the speedometer as 100 kmh.

Mass is a bit of a mixed bag. In some cases it doesn't matter. A 10 pound bowling ball is too light for me, and 16 pounds is too heavy. They're just numbers and I know I what range I like. Body-weight, kinda same thing, I know what the scale says and where I want to be—just numbers. But if anyone requires me to do arithmetic on pounds and ounces I usually convert to metric, much easier to do the math. I still don't know—and don't care—how many ounces go in a pound, especially as it seems to vary (solid/fluid). Or maybe not, but it's just confusing.

It's not the units themselves that drive SI folks insane. I couldn't care less if we switch to the yard as the base unit of measure tomorrow, if that's what it takes to get the world on a single unit ("freedom meters?"), I can handle that. It's the insanity of different scales for every physical property that can only be learned by sheer memorization, which is hard when you don't grow up on it. “The doohikey is 2⁵⁄₁₆″ wide.” Who comes up with that? Now I have to do arithmetic to figure it's slightly more than 2¼ (but how much more?) I can deal with 2.31″ but good luck finding a ruler or calipers that show that.

My point is, adapting from imperial to metric is a lot easier than adapting from metric to imperial. Getting a feeling for how large each unit is, is easy; base units are just as arbitrary in metric (although conveniently chosen but that's besides the point). It's the batexcrements crazy math that is required, that has no rhyme or reason, which is what "SI peope" will ridicule ("so you're measuring that in... what, leagues per fortnight?")

At FL400, atmospheric pressure is about ⅕ of that on sea level. The passenger next to you has gone over the edge is is trying to open the emergency exit (3×4′), which opens inward. How worried should you be? What is the force required? In metric (assuming a door size of 1×1.3m), this takes about 10s to solve without a calculator. (and no, no need to worry, it takes about 10 tonnes of force).

 

Edited January 14, 2023 by Kerbart

[Pthigrivi]

1 hour ago, Hannu2 said:

Actually I would be happy if there were global compromise. Units could be imperial but one unit per quantity and decimal notations instead those very impractical rationals. For example an inch would be very practical unit in everyday needs. Most objects I handle have size of 1-10 inch. Kilometer would be 40 kiloinch. Megainch (25.4 km) would be quite practical for everyday traveling purposes. And I have already very used to mils (milli-inch), which is very common unit in electronic engineering.

Unfortunately 40 kiloinches doesn’t really solve the problem. The whole point of metric and si is that conversion between units and scales always means moving the decimal point left or right, not doing division that results in remainders. A kilometer would need to be exactly 1 kiloinch. This is what makes architecture hell, and is part of the reason we have such a reputation for errors. We constantly go from civil engineering scales (1”=10, 20, 50, or 100ft”) to architectural scales (1/8”, 1/4” 1/2”, sometimes 3/16” or 3/8”=1’) or to detail scales, or you simply have to jump between feet and inches (1/12) or fractions of an inch (sometimes decimal, sometimes binary fractions all the way down) , and each time a switch is made there is risk of error. Those errors while rare are almost always very expensive and exclusively our fault leading to lawsuits, driving up insurance and the fundamental cost of design. Ive seen a scale error result in a 20 million dollar building being built 10ft over a setback and need to have a wing demolished and redesigned 2 months before it was meant to be completed. Its by no means the largest source of errors in the field, but it makes communication and work-checking much more time consuming and its 100% needless.

Edited January 14, 2023 by Pthigrivi

[StrandedonEarth]

4 hours ago, Hannu2 said:

Actually I would be happy if there were global compromise. Units could be imperial but one unit per quantity and decimal notations instead those very impractical rationals. For example an inch would be very practical unit in everyday needs. Most objects I handle have size of 1-10 inch. Kilometer would be 40 kiloinch. Megainch (25.4 km) would be quite practical for everyday traveling purposes. And I have already very used to mils (milli-inch), which is very common unit in electronic engineering.

I’m currently about 1.6 gigaseconds old…

Edited January 14, 2023 by StrandedonEarth

[JoeSchmuckatelli]

6 hours ago, Kerbart said:

Getting a feeling for how large each unit is, is easy

An inch is about the length of a man's forefinger (from the bend to the tip).  A foot is (guess).  But also 12 'finger digit lengths' - which means its easy to divide by 3 or 4; quarters are common!

A yard is 3 feet.

A mile is a thousand paces (every time the left foot hits in an average-sized man's stride, that's a 'pace')

 

Centimeter?  totally arbitrary.

Edited January 14, 2023 by JoeSchmuckatelli

[Deddly]

1 hour ago, JoeSchmuckatelli said:

Centimeter?  totally arbitrary.

Not at all. A centimetre is the average depth of snow that melts into a 1-millimetre-deep puddle of water.

[Codraroll]

2 hours ago, JoeSchmuckatelli said:

Centimeter?  totally arbitrary.

It's approximately the width of each of your fingernails, if you want a body analogy. That also makes your fingernails roughly one square centimeter.

But then again, being arbitrary is not a problem, I'd say. The value of a centimeter is not the selling point, it's how it fits in an easy-to-scale system where units fit nicely together in base ten. I could learn to live with inches and pounds if there were simple and easy relations between the various units of length, volume, and mass that make conversions a breeze.  Maybe add speed and force to the mix too. But the Imperial system decides to denote some of this in base 12, some in base 16, and some in base 8, or 10 depending on local customs. The common units of length and volume have nothing to do with each other. The more scientific you try to be, multiplying units with each other to work out complex problems, the worse it becomes. Metric is smooth sailing all the way, with the only hiccups arising from the occasional conversion of minutes or hours to seconds. If accuracy is not absolutely crucial, you can even approximate gravity to 10, and density to 1 for most organic substances - it makes a lot of calculations very simple to do in your head.

And again, division by fractions is overrated. The value you start with before divisions is rarely a whole number of units anyway.

[Kerbart]

3 hours ago, JoeSchmuckatelli said:

An inch is about the length of a man's forefinger (from the bend to the tip).  A foot is (guess).  But also 12 'finger digit lengths' - which means its easy to divide by 3 or 4; quarters are common!

A yard is 3 feet.

A mile is a thousand paces (every time the left foot hits in an average-sized man's stride, that's a 'pace')

 

Centimeter?  totally arbitrary.

I hear this argument ad nauseum and it's not what I meant. If someone tells me "it's 10 cm" or "it's 2½ m" I know what size it is. Why? I grew up with those units. Same with inches and feet. If someone tells you "it's 17 inches" are you going to lay out finger by finger 17 times? No? Then "an inch is about the length of a forefinger" is not the reason you know what 17 inches look like; it's because you grow up with them so you know its size.

The perceived magical relationship to body parts has nothing to do with familiarity. Do you think that "an altitude of 40,000 feet" has any meaning to me when trying to figure out how high that is? Can you even imagine 40,000 feet lined up? We know what certain  dimensions are in real life because we know. We're familiar with them. What they're based on is pretty arbitrary. A foot? Whose foot? Napoleon is portrayed as a tiny man because French feet (the unit) were larger than English ones, so when the English considered his size they though he was small. The Wasa sank because one half of the ship was built by Dutch workmen using Amsterdam feet, the other half was built using Swedish feet. The difference was good enough to make her capsize within a short distance (whether that's a kilometer or a mile doesn't really matter, especially not for the people on board) after launching.

So when you're talking about an inch or a foot being derived from body parts... maybe, but still arbitrarily picked because it's not a standard size, and what you call an inch is not because it's the length of your finger, but because some people decided that this finger is the one to use (even worse, the current definition of the inch isn't a body part at all... It's 2.54 cm).

Now that we're down to arbitrary units... We have feet and inches defined by someones hand and feet, and pounds that are... (wait, you didn't tell me what the pound is based on) based on something, I guess. Then we have the metric system. The meter, again, is an arbitrary unit (originally based on being a tenth of a million of the distance from the equator to the north pole). And mass is based on a kilogram, being one liter of water (1 cubic dm). And conveniently atmospheric pressure hovers around (using the wrong units) 1 kg/cm². Well, now we're rapidly getting into convenient territory. A boiler that holds 25 m³? No special math needed to know it's 25 tons of water. One less mistake for engineers to make. Diving at 40m depth? Well that's going to be 4× atmospheric pressure, so you'll use your air 4× as fast compared to the surface. Pretty inconvenient to get that wrong when applying conversion factors. Trying to find a relation between flow in a river (cubic meters per second) and how much it will flood an area doesn't requires special skills (how many gallons in an acre-foot? Quick! - the answer is 325,851³⁄₇, by the way).

We both like our arbitrary units. But I do have the opinion that doing something with them has more use than being able to count out how many body parts they represent.

[JoeSchmuckatelli]

1 hour ago, Kerbart said:

arbitrary

That was some first class ranting.

I'm not kidding; very well done.

Not even going to quibble with you.  I'm still in awe of your artistry!

(You're absolutely correct, tho.  No one measures 17 inches; we just 'know' it's about that so we go with it.. and 40,000 ft. is just a number that's largely meaningless off paper when your feet are planted on the earth.)

[kerbiloid]

7 hours ago, JoeSchmuckatelli said:

A foot is (guess). 

The medieval people were living in harmony with nature, starving, and thus were shorter. The "foot" is a medieval boot.

Originally they were taking off a boot and using it as a ruler, later it was recommended taking an average of several of them.
In the mentioned text, sixteen boots were put in a row. Then you take a rope, measure the total length and fold it twice, twice, twice, twice. The resultin 1/16 is a local foot for this village on that exact day.

7 hours ago, JoeSchmuckatelli said:

A yard is 3 feet.

The yard was officially defined as the distance between some British king's nose and thumb.

Three feet were matching it later.

(Still can't understand, how did they put three boots to the king's nose).

The same with fingers.
Also the finger is actually 1/4 of hand (four fingers held together), so it's not 12 fingers in a foot, but the foot is 3 hands, which are 12 fingers.

7 hours ago, JoeSchmuckatelli said:

A mile is a thousand paces (every time the left foot hits in an average-sized man's stride, that's a 'pace')

And this makes it highly arbitrary, because various roads were measured by the men of various height.

7 hours ago, JoeSchmuckatelli said:

Centimeter

Happily, we have a centimeter, which is 1/100 of 1/40 000 000 of the Parisian meridian, which we can easily measure.

Or now it's a 1/100 of 1/299 792 458 of a light second, so you can just use your clock.

[TomKerbal]

2 hours ago, kerbiloid said:

The medieval people were living in harmony with nature, starving, and thus were shorter. The "foot" is a medieval boot.

Originally they were taking off a boot and using it as a ruler, later it was recommended taking an average of several of them.
In the mentioned text, sixteen boots were put in a row. Then you take a rope, measure the total length and fold it twice, twice, twice, twice. The resultin 1/16 is a local foot for this village on that exact day.

The yard was officially defined as the distance between some British king's nose and thumb.

Three feet were matching it later.

(Still can't understand, how did they put three boots to the king's nose).

The same with fingers.
Also the finger is actually 1/4 of hand (four fingers held together), so it's not 12 fingers in a foot, but the foot is 3 hands, which are 12 fingers.

And this makes it highly arbitrary, because various roads were measured by the men of various height.

Happily, we have a centimeter, which is 1/100 of 1/40 000 000 of the Parisian meridian, which we can easily measure.

Or now it's a 1/100 of 1/299 792 458 of a light second, so you can just use your clock.

Yes, 1m is easily to measure. Normally I use a folding ruler for it. Try using weight scales for measuring weights as well. I think it's much more precise than "measuring" a distance in inches with your finger. That's medieval. And that's o.k. But nor for science and engineering.

I think that has become clear. I also like units you can easily imagine, like inch now (thanks for explaining! I will use it more often from now on!). But if you start calculating something more complex you suddenly know what we SI-people are talking about. You just don't have to care about units at all (!) when transforming equations in SI-System! And that is because it is a so called "consistent" unit system.  And, as you can already imagine, the imperial unit system is not a consistent unit system. No, it's not. From my point of view as a scientist that's the by far the most important difference between SI and imperial units.

So I like a mixture of SI and imperial units. Use the units you and people around can imagine but only use SI for (complex) calculation and switch to common units when talking about SI based calculations (like 1000bar pressure instead of 100000000 Pa). And be careful when using mass based units for forces (like kg.f). A "tonne" is a mass and not a force. When using it for a force it's meant to be the gravitational force of 1t at technical standard gravitational acceleration (9,80665m/s^2). So when being at moon I always multiply it by the factor of 6 for my lander designing :-)  Not exact but nice for good and quick estimations ( I really like them; and imperial units could perhaps be helpful for that purpose.. I really have to think about that). And last not least: 1bar for every 10m water depth you are diving (well, approximately, since water is not fully incompressible).

 

[TomKerbal]

I just measured it: 1cm is pretty much the length of the fingernail of my little finger (nail cut short, but not quite short, just normal short, or something). :-) How about that ? I mean, an inch is nice, but combine it with a centimeter ! Wuaa

Edited January 15, 2023 by TomKerbal

[kerbiloid]

The Planck units. They are natural and depend on the personal finger.

Table 1: Modern values for Planck's original choice of quantities

Name	Dimension	Expression	Value (SI units)
Planck length	length (L)	{\displaystyle l_{\text{P}}={\sqrt {\frac {\hbar G}{c^{3}}}}}	1.616255(18)×10−35 m[7]
Planck mass	mass (M)	{\displaystyle m_{\text{P}}={\sqrt {\frac {\hbar c}{G}}}}	2.176434(24)×10−8 kg[8]
Planck time	time (T)	{\displaystyle t_{\text{P}}={\sqrt {\frac {\hbar G}{c^{5}}}}}	5.391247(60)×10−44 s[9]
Planck temperature	temperature (Θ)	{\displaystyle T_{\text{P}}={\sqrt {\frac {\hbar c^{5}}{Gk_{\text{B}}^{2}}}}}	1.416784(16)×1032 K[10]

Best use with prefixes 

SI prefixes

• v
• t
• e

Prefix Base 10 Decimal Adoption
^{[nb 1]} Name Symbol quetta Q 10³⁰ 1000000000000000000000000000000 2022 ronna R 10²⁷ 1000000000000000000000000000 2022 yotta Y 10²⁴ 1000000000000000000000000 1991 zetta Z 10²¹ 1000000000000000000000 1991 exa E 10¹⁸ 1000000000000000000 1975 peta P 10¹⁵ 1000000000000000 1975 tera T 10¹² 1000000000000 1960 giga G 10⁹ 1000000000 1960 mega M 10⁶ 1000000 1873 kilo k 10³ 1000 1795 hecto h 10² 100 1795 deca da 10¹ 10 1795   10⁰ 1 — deci d 10⁻¹ 0.1 1795 centi c 10⁻² 0.01 1795 milli m 10⁻³ 0.001 1795 micro μ 10⁻⁶ 0.000001 1873 nano n 10⁻⁹ 0.000000001 1960 pico p 10⁻¹² 0.000000000001 1960 femto f 10⁻¹⁵ 0.000000000000001 1964 atto a 10⁻¹⁸ 0.000000000000000001 1964 zepto z 10⁻²¹ 0.000000000000000000001 1991 yocto y 10⁻²⁴ 0.000000000000000000000001 1991 ronto r 10⁻²⁷ 0.000000000000000000000000001 2022 quecto q 10⁻³⁰ 0.000000000000000000000000000001 2022

Notes

1. ^ Prefixes adopted before 1960 already existed before SI. The introduction of the CGS system was in 1873.

 

Probably have to add more of them, or change them into a simple and clear system like the superheavy chemical element naming.

Summary of element naming proposals and final decisions for elements 101–112 (those covered in the TWG report)^[9]

Atomic number	Mendeleev	Systematic	American	Russian	German	Compromise 92	IUPAC 94	AmericanChemSoc 94	IUPAC 95	IUPAC 97	Present
101	eka-thulium	(unnilunium)	mendelevium	—	—	mendelevium	mendelevium	mendelevium	mendelevium	mendelevium	mendelevium
102	eka-ytterbium	(unnilbium)	nobelium	joliotium	—	joliotium	nobelium	nobelium	flerovium	nobelium	nobelium
103	eka-lutetium	(unniltrium)	lawrencium	rutherfordium	—	lawrencium	lawrencium	lawrencium	lawrencium	lawrencium	lawrencium
104	eka-hafnium	unnilquadium	rutherfordium	kurchatovium	—	meitnerium	dubnium	rutherfordium	dubnium	rutherfordium	rutherfordium
105	eka-tantalum	unnilpentium	hahnium	nielsbohrium	—	kurchatovium	joliotium	hahnium	joliotium	dubnium	dubnium
106	eka-tungsten	unnilhexium	seaborgium	—	—	rutherfordium	rutherfordium	seaborgium	seaborgium	seaborgium	seaborgium
107	eka-rhenium	unnilseptium	—	—	nielsbohrium	nielsbohrium	bohrium	nielsbohrium	nielsbohrium	bohrium	bohrium
108	eka-osmium	unniloctium	—	—	hassium	hassium	hahnium	hassium	hahnium	hassium	hassium
109	eka-iridium	unnilennium	—	—	meitnerium	hahnium	meitnerium	meitnerium	meitnerium	meitnerium	meitnerium
110	eka-platinum	ununnilium	hahnium	becquerelium	darmstadtium	—	—	—	—	—	darmstadtium
111	eka-gold	unununium	—	—	roentgenium	—	—	—	—	—	roentgenium
112	eka-mercury	ununbium	—	—	copernicium	—	—	—	—	—	copernicium

You take the element number and replace the digits with their greek-o-latin equivalents and add -ium. (The double letters are merged. "-iium" → "-ium")

0 = nil, 1 = un, 2 = bi, 3 = tri, 4 = quad, 5 = pent, 6 = hex, 7 = sept, 8 = oct, 9 = enn

(Notice the linguistic elegance: nil/un/bi/tri/quad/pent/hex/sept/oct/enn. L - LyngviΣτύξ, L - Lωγyck).

Thus, the 145th element is un+quad+pent+ium = unquadpentium, 763th = septhextrium.

The hydrogen is probably unium, oxygen = octium, water = diunium octiumide, lithium = trium, aluminium = untrium, iron = duhexium, rust = duhexium triuniumoctiumide, uranium = ennduium, plutonium = ennquadium, and so on.

This way we can replace the idiotic set of zetta/yotta/ronna/quetta into plain and simple duun-, duquad-, dusept-, trinil-.
Negative value like the ugly zepto/yocto/ronto/quecto can be, say, an(ti)-, like anduun-, anduquad-, andusept-, antrinil-.

Say, a light year ~= 9.5*10¹⁵ m, i.e. 9.5 unpentometers.

***

Thus, by merging this system of prefixes and the Planck units, we can see:

Length: 1 planck ~= 1.6*10^-35 m.

So,
1 m ~= 6.3*10³⁴ planck = 6.3 triquadoplanck.
1 ft ~= 1.9 triquadoplanck.
1 triquadoplanck ~= 16 cm.
1 tripentoplanck ~= 1.6 m.

Thus, we can take either triquadoplanck or tripentoplanck as basic unit for daily needs and call it just "planck" (because we can't confuse it with the planck unit).

Say, 1.83 m / 6 ft height is 11.5 plancks.

***

But why limit ourselves to decimal?
What if use duodecimals?

1 planck ~= 1.616*10^-35 m.

1 m ~= 6.188*10³⁴ planck ~= 1.81_decimal*12³² planck = 1.81_decimal triduplanck.

1 triduplanck ~= 55.3 cm.
1 triunplanck ~= 5.53 cm.
1 trinilplanck ~= 0.553 cm.

Say, 1.83 m / 6 ft height is 33 trinilplanck (or just "planck") if use duodecimals.

***

Some confusion will be caused by the "second", because we need integer seconds in a day, and 86400 looks enough perfect.

1 planck ~= 5.39125*10⁻⁴⁴ s

1 s ~= 1.865_decimal*10⁴³ planck = 1.269_decimal*12⁴⁰ planck,

But if split a minute into 72 seconds, or an hour into 72 minutes, the "short second" = 1.0575decimal *12⁴⁰ planck,

So, 1 short second ~= 1 quadnilplanck, and can be named "1 planck" for daily needs.

As the astronomic "second" anyway doesn't match its physical definition, it's absolutely enough for practical use.

***

The mass is quite simple.

1 planck ~= 2.176434(24)×10⁻⁸ kg

1 kg ~= 4.6*10⁷ planck ~= 1.28*12⁷ planck = 1.28 septoplanck.

So, we can take 1 septoplanck = 781_dec g as a daily "1 planck" and replace both kilogram and pound.

So, the mentioned "3 half-pounds of meat" = 3 * 453.6 / 781 = 1.75 plancks of meat, or "two without quarter plancks of meat".

***

Temperature.

1 planck = 1.416784(16)×10³² K

1 K ~= 7.05823894*10^-33 planck ~= 7.16_dec*12²⁹ planck = 7.16 duennplanck.

The ugly standards are: 0.100 °C (between ice and steam, which depend on pressure and so on) and 0..180 °F (ammonia and alcohol, which are more stable, but hardly available).

So, we currently use 0.56 .. 1.0 K units = 4..7 duennplancks,

Also we measure the body temperature with 0.1 K precision, so we need something between 0.7 and 7 duennplancks, distinguishing 36.6, 36.7, 36.8 but needing no such precicision outside this range.

This makes the duennplanck as a daily "1 planck".

Edited January 15, 2023 by kerbiloid

[Kermann Nolandung]

21 hours ago, kerbiloid said:

+1!

1 pound = 1 kg
1 ton = 1 tonne = 1000 kg
1 yard = 1 m
1 mile = 1000 m (naut. mile still 1852)
1 foot = 1/4 yard = 25 cm, i.e.a woman foot of ~38 EU.
1 inch = 2.5 cm = 1/10 of ft (which is 25 cm)
1 second = 1  second
1°F = 1K

  Reveal hidden contents

1 USD = 1 RUR

12 = 10

The pound has a definition in imperial units, but it also existed in various other measurement systems.
It may be recalled that the ounce used today for trading precious metals inherited one of them (1 troy ounce ≈ 1.097 ounces).
Although I live in an all metric country, I remember going to the market with my grandmother and asking the butcher for a pound or half pound of meat, here a pound meant 500g.

so 1 pound = 500g is my preference

I wonder if this informal usage is widespread in Europe.

I found out that this is the definition given in the customary measurements system in France.
https://en.wikipedia.org/wiki/Mesures_usuelles

[tomf]

18 hours ago, Kerbart said:

Diving at 40m depth? Well that's going to be 4× atmospheric pressure, so you'll use your air 4× as fast compared to the surface

Ah you made the classic error, at 40m the pressure is 5 atmospheres, and what are these forums for if not needless pedantry.

But seriously I have tried diving in Imperial units and I can't imagine how anyone properly plans a dive. The ridiculous way Americans define the size of a cylinder, as the volume that gas stored at a particular pressure will assume at atmospheric pressure, doesn't help though.

[Hannu2]

On 1/15/2023 at 1:57 PM, Kermann Nolandung said:

so 1 pound = 500g is my preference

I wonder if this informal usage is widespread in Europe.

 

Not in Finland. However, inches are commonly used in spoken language, especially in carpentry and other handcrafting. Nor example 100 mm nail is called "four inch nail" and 96x48 mm plank is "2x4 inch".

[Gargamel]

On 1/15/2023 at 6:57 AM, Kermann Nolandung said:

so 1 pound = 500g is my preference

The problem with that is there is too much error.   The extra 10%/20% adds up quickly. 

It’s not like where you can easily do 1 inch = 25mm and 6 inches is 150mm or 60 inches is 1.5m, where the % error is small enough that unless you need a precise conversion, 25-1 is good enough in most cases.    
 

With mass, doing 2.2-1 in my head is easy enough, especially with practice after years of being a paramedic.   Take a persons weight in pounds, divide by 2, subtract 10%.  Boom kilos.   And to go the other way, add 10%,  multiply by 2, and pounds.    Still a bit of error, but close enough.