Metric or traditional inch system?

[Tam]

Metric was blamed for the crash of NASA’s Mars Climate Orbiter in 1999 because the Jet Propulsion Laboratory thought it's supposed to be in Metric as required by the contract that was signed off for the builder Boeing but they forgot that Boeing is located in the U.S.:

 

[cpa]

In your example I'd say either "45 cm" or "a bit under half a metre", depending on context.


FWIW, I've lived about half of my life in metric countries (plural), and I for one prefer imperial (which is sort of an odd thing to call it at this point) measurements for weather (I feel like the wider bands of fahrenheit make for easier conversation: "What's the forecast?" "70s"), and casual distance/size discussion ("How tall are you?" "6'4").

For precision measurements I prefer metric.

I think we are saying sorta the same thing. Precision measurements, no doubt metric wins. But in routine conversation, standard seems easier to perceive.

Kudos to you to be able to discern about 45 centimeters. Without doing the math in my head, I would have guessed that 18 inches was about 35 centimeters.

 

[Webeevdrivers]

It's harder now than it was then, for a huge variety of reasons.

But aren’t we getting smarter?

Never mind, I just saw Fox News.

 

[destructure00]

Does Tesla use the Metric or traditional inch system in regards to tools when cars are serviced, such as Mercedes that is metric?

All the fasteners on the car are metric.

 

[RayK]

But aren’t we getting smarter?

Never mind, I just saw Fox News.

Touché.

 

[ucmndd]

I think we are saying sorta the same thing. Precision measurements, no doubt metric wins. But in routine conversation, standard seems easier to perceive.

Kudos to you to be able to discern about 45 centimeters. Without doing the math in my head, I would have guessed that 18 inches was about 35 centimeters.

I think it’s entirely perception and experience. I don’t find a centimeter any more or less difficult to perceive than an inch in casual conversation. Same with a meter vs. yard, km vs mile. The conversion between the two seems easy enough to me because it’s constant:

A foot is about 30 centimeters.
A meter is about a yard.
A mile is about 1.5 kilometers.

Easy enough to convert between the two.

I do admit I struggle more with temperature conversion, because the scales are fundamentally different.

But I think the barriers to conversion in this thread are greatly overstated. As someone mentioned above, for all practical purposes the conversion has already happened. Nearly all scientific activity is carried out in the metric system. Textbooks have been metric for at least a generation. I don’t see any particular reason or value in going back and correcting laws or legal descriptions from a bygone era - you simply make the switch moving forward. It will be fully complete within a generation.

 

[Tam]

But aren’t we getting smarter?

I think it's a matter of agreeing on a standard.

When the Pepboy mechanic working with a first Tesla had trouble of getting the right lug nut size for my tire, he asked whether it's 3/4, 13/16 or 7/8?

I reflexively told him 21mm because that's what I remembered from the owner's manual and he instantly took out a 21mm from the toolbox without any problem.

I didn't give him his Imperial size as he preferred because Tesla forced me to utter Metric when it didn't list the Imperial lug nut size in the manual but he didn't have any trouble with the Metric because he had both kinds of sockets.

But that's kind of expensive to buy 2 sets of tools.

 

[hugh_jassol]

I just ordered Wednesday and began looking at the owner's manual yesterday. Didn't know it was so hard to get a one word answer LOL

This is nothing. Ask what level you should charge to on a daily basis.

 

[drift]

I think it's a matter of agreeing on a standard.

When the Pepboy mechanic working with a first Tesla had trouble of getting the right lug nut size for my tire, he asked whether it's 3/4, 13/16 or 7/8?

I reflexively told him 21mm because that's what I remembered from the owner's manual and he instantly took out a 21mm from the toolbox without any problem.

I didn't give him his Imperial size as he preferred because Tesla forced me to utter Metric when it didn't list the Imperial lug nut size in the manual but he didn't have any trouble with the Metric because he had both kinds of sockets.

But that's kind of expensive to buy 2 sets of tools.

Two sets of tool aren't required. Can anyone show me a metric watch/clock or metric calendar?

 

[holmgang]

This is a serious question:

I am well into my seventh decade, and obviously I have used the imperial system my entire life. What I like about it is that the measurements standards are easy to eyeball and explain. Eighteen inches is pretty easy to mark off. For those using the metric system, what do you say? Forty-five hundredths of a meter? Four and one-half decimeters? Forty-five centimeters? Four hundred fifty or so millimeters? I can pretty closely visualize a meter, centimeter, and millimeter. But visualizing tens of centimeters or hundreds of millimeters is difficult for me.

I guess it is hard for me to visualize lots of tiny units or significant fractions of larger units when the imperial system has refined the units into small, medium, large, and extra large.

of all the bad excuses for keeping imperial, this particular one - of how one person can intuit a length - is about the worst.

how does 99% of the world imagine 18"? and if they cant, is that adequate proof inches are rubbish?

those people would never say, or need to say forty-five hundredths of a meter. but they would know its roughly half a meter. which is the same as 45 centimeter. and they would know forty-five hundredths of a centimeter is 4.5mm.

what's half an inch? why are there 24 of them in a foot? and how does it relate to a furlong?

i always thought it was ludicrous when new tire are quoted with tread depth of 10/32", and wear limit is 2/32". utter inanity.

slightly tangential to this, sharing the same fractional affectional of the imperial system is the monetary system:

quote matt levine

We talk about it less than we used to, but they still are. Here’s the New York Fed’s Liberty Street Economics blog with “ How Does Tick Size Affect Treasury Market Liquidity?” I have to say, this isn’t new news or anything, but Treasury tick sizes are absolutely wild:

Unlike U.S. equity markets, which switched to decimal pricing in 2001, U.S. Treasury securities still trade in fractions. In particular, prices are quoted in 32nds of a point, where a point equals one percent of par, with the 32nds themselves split into fractions. On the BrokerTec platform, for example, 3- and 5-year notes trade in quarters of 32nds, whereas 7-, 10-, and 30-year securities trade in halves of 32nds. The quoted price for a 5-year note might be 98-15¼, for example, indicating a price in decimal form of 98.4765625 (that is, 98 + 15⁄32 + ¼⁄32).

Imagine coming up with that! Imagine being a human, with 10 fingers and 10 toes and centuries of decimal-based culture, and being like “instead of using 100ths of a point, we’ll use 128ths of a point, and we won’t even call them ‘128ths,’ we’ll call them ‘quarters of 32nds.’” Of course that’s not what happened, no one designed this; what happened is just that prices were quoted in points, and then someone wanted a bit more precision and went to half-points, and then someone wanted a bit more precision and went to quarter-points, and then the binary subdividing continued for a while and stabilized at 32nds, and then when it picked up again everyone was so used to 32nds that you had to say “half of a 32nd” instead of “1/64th.” (Actually it’s worse than that, you say “+”; a quote of 100 and 63/64ths—100.984375 in human language—is written, insanely, as “100-31+.”)

It is an archaeological demonstration of path dependency in finance, a bizarrely branching vestigial tail. I confidently assert that hundreds of computer programmers have shown up on their first day of work at financial services firms to build bond trading platforms, and they were like “we’ll let people input prices up to four decimal places, does that sound good,” and their bosses were like “hahaha decimals no we don’t use decimals here,” and they went slowly mad. No one could possibly want this, but it’s what we have.

 

[hugh_jassol]

Behind the scenes almost all industry, government and science HAS switched. We just show the "dumb" Imperial face to the general public.

I work for <redacted> that does <redacted> and by rule we use metric (SI units) for everything and we write into our subcontracts that all work performed for us use SI units. Occasionally, we have to give press conferences, public presentations, interviews for articles, and the like. Every time we have to go through with our PR people on how to "simplify it" for the general (American) public. This usually involves length units of "a person" and/or (American) football fields.

 

[hugh_jassol]

Can anyone show me a metric watch/clock or metric calendar?

seconds are part of the SI system (meters-grams-seconds)

No one that uses time for anything "real" (defined as needing to do any calculation) uses a calendar. All systems use seconds since an Epoch and then it is converted into what we call "wall clock time" when needed.

Epochs that are used in probably 10-20 things in your house right now:

• GPS time is number of seconds since midnight UTC, Jan 5, 1980
• Unix official time is seconds since midnight UTC Jan 1, 1970

This way you don't have to worry about leap seconds, leap years, etc. These are monotonically incrementing seconds.

 

[ALSETJC]

Conversion to different units is far superior in metric, base 10s. Living in Canada we get exposed to both and are pretty comfortable with either. I'm not trying to insult anyone but metric is factually superior. It's about time the U.S. joins the fun. It's not as hard to switch as it's made out to be, it just takes time. You might as well start as soon as possible. Comfort or perception explanations are just that, what you grew up with. It takes a new generation to begin to get comfortable with the new measurements.

 

[run-the-joules]

I'm not trying to insult anyone but metric is factually superior.

Superiority is a matter of opinion. It’s like saying it’s a fact that salmon is superior to tuna.

 

[SageBrush]

In your example I'd say either "45 cm" or "a bit under half a metre", depending on context.


FWIW, I've lived about half of my life in metric countries (plural), and I for one prefer imperial (which is sort of an odd thing to call it at this point) measurements for weather (I feel like the wider bands of fahrenheit make for easier conversation: "What's the forecast?" "70s"), and casual distance/size discussion ("How tall are you?" "6'4").

For precision measurements I prefer metric.

I'm also an Imperial/metric hybrid.

For day to day use I do not really care which is used but for anything science related I just refuse to even try Imperial. And if calculations are involved then Imperial is something between a devious torture scheme and impenetrable

It is said that the UK lost its science prominence to mainland Europe due to Newtons' steadfast refusal to adopt modern day notation for calculus. Sounds about right to me. Imperial units have the same flavor but with few exceptions science in Imperial countries is also metric. They ain't stupid.

 

[SageBrush]

I think it’s entirely perception and experience. I don’t find a centimeter any more or less difficult to perceive than an inch in casual conversation. Same with a meter vs. yard, km vs mile. The conversion between the two seems easy enough to me because it’s constant:

A foot is about 30 centimeters.
A meter is about a yard.
A mile is about 1.5 kilometers.

I also have a couple conversions memorized. E.g., I remember that
0C = 32F
20C = 68F
30C = 86F
40C = 104F

I pick the closest and then estimate with 1C = 2F.

But I usually do not convert anything. For day to day use in any system I just know from experience a few specifics:
I can can show the span of a meter with my hands; or a cm between thumb and finger
If I pick up a Kg I know it
Pleasant outside ? About 18-20C

I have analogous internalized measurements for a few Imperial units.

It is not a big deal.

 

[JulienW]

Superiority is a matter of opinion. It’s like saying it’s a fact that salmon is superior to tuna.

But if you need an accurate or scientific measurement you MUST use metric since it is an absolute with defined measurements while Imperial isn't. Imperial uses metric to define its measurements so that in and of itself means it is inferior and metric is superior, much less the complexities and randomness of divisions (1 mile = 5280' or 128 oz = 1 gallon).

Also Salmon is superior since it contains more Omega-3 fat. While Tuna does have more Protein we generally don't need more Protein but do need more Omega-3 fat.

 

[SageBrush]

Imperial uses metric to define it's measurements so that in and of itself means it is inferior

If derived means inferior then clearly the cm is inferior to the meter.
And remember that one meter is based on 1/299792458 seconds. That sounds completely capricious, just like Imperial units

 

[JulienW]

If derived means inferior then clearly the cm is inferior to the meter.
And remember that one meter is based on 1/299792458 seconds. That sounds completely capricious, just like Imperial units

Didn't say derived. I said that Imperial has NO standards or accuracy and MUST use metric to be defined. Also using 1/299792458 of C gives the Meter an accurate standard that is THEN used to define an inch. Also Imperial falls apart once you get micro. You can't accurately measure the diameter of a hair with Imperial.

 

[SageBrush]

Didn't say derived. I said that Imperial has NO standards or accuracy and MUST use metric to be defined. Also using 1/299792458 of C gives the Meter an accurate standard that is THEN used to define an inch. Also Imperial falls apart once you get micro. You can't accurately measure the diameter of a hair with Imperial.

I stand corrected.

If a cm is defined by a meter ...



---
Kidding aside, 1/299792458 of C is painful.
Start with C divided by 10^4, 10^5 and divided by 10^6 for everyday use distance units.
And for heavens sake get rid of base 60 time units.