Convenience of the metric system

[valhalla360]

I can work in either system though I find english units more intuitive.

Interestingly, I'm helping out one of our overseas offices and part of my job is to review another engineering firms work. This is a large multinational firm and I am constantly finding issues where the decimal point is off by a digit or two.

I suspect they don't have the intuitive feel that english units provide. (and their designers are a bit sloppy in general)

[K_V_B]

Originally Posted by valhalla360

I can work in either system though I find english units more intuitive.

That's probably just because you are used to them. I find nothing intuitive about English Units. Can you immediately answer

Interestingly, I'm helping out one of our overseas offices and part of my job is to review another engineering firms work. This is a large multinational firm and I am constantly finding issues where the decimal point is off by a digit or two.

I suspect they don't have the intuitive feel that english units provide. (and their designers are a bit sloppy in general)

I guest either their engineers are _extremely_ sloppy, to the point of being negligent. Or they are mixing m and cm, and you are not spotting it...

Yesterday I attended an astrophysics lecture given by an American professor. One interesting thing is that he gave small dimensions in cm, like 10^-27 cm. This is not something I would ever do. I would just write 10^-29 m. Notice btw how easy this conversion was...
Anyway, for technical drawings I was told to just either use mm or m depending on what I was designing. m for a house for example, mm for machinery.

English Units? Not intuitive at all. Just the fact that the US and the UK can't even agree on how big a Gallon is, and the US itself has two definitions of what a "feet" is already says enought. Hof many times can you fit 2 3/8 Inch in 5 1/2 yards? Can you answer that without googling?

[valhalla360]

Originally Posted by K_V_B

That's probably just because you are used to them. I find nothing intuitive about English Units. Can you immediately answer

English units are typically based on the human body. While they have been locked down for consistency, you have a built in set of references (ie: an inch is around the distance from the tip of your thumb to the first joint. A meter was originally intended to be 1/10,000 the distance from the earths pole to the equator. I believe the latest is based on how far light travels during a specified number of vibrations of a particular type of atom. Which one is more intuitive?

I guest either their engineers are _extremely_ sloppy, to the point of being negligent. Or they are mixing m and cm, and you are not spotting it...

I will agree they are sloppy. They are mixing m, cm and mm. The point was I AM SPOTTING it.

Yesterday I attended an astrophysics lecture given by an American professor. One interesting thing is that he gave small dimensions in cm, like 10^-27 cm. This is not something I would ever do. I would just write 10^-29 m. Notice btw how easy this conversion was...
Anyway, for technical drawings I was told to just either use mm or m depending on what I was designing. m for a house for example, mm for machinery.

For something like astrophysics, there often is nothing intuative to work from, so it's a different situation. These are measurements that have no intuitive relationship to anything.

English Units? Not intuitive at all. Just the fact that the US and the UK can't even agree on how big a Gallon is, and the US itself has two definitions of what a "feet" is already says enought. Hof many times can you fit 2 3/8 Inch in 5 1/2 yards? Can you answer that without googling?

Did they stop teaching kids how to work with fractions in metric countries? As soon as you can anser how many times you can divide 37mm into 5.87m without a calcualtor or a piece of paper, I'll give you that point.

You are confusing the use of fractions with english units. Nothing about english units says you can't use 5.5 yards nor is there anything with metric units that prohibits the use of 5 1/2 meters. There are times when a fraction more precisely defines a measurement. 5.3 meters is close but not the same as 5 1/3 meters.

My point is a lot of these issues I'm coming across seem to be tied to the relative ease of converting units. It's so easy to just shift a decimal point without an intuitive sense of what you did that these mistakes are creeping in.

While this company is particularly bad, I can easily see similar mistakes slipping thru just the same as conversion mistakes with english units can creep thru.

[UNCIVILIZED]

Having been schooled as an Engineer (using the English/American System), does anyone have some words of wisdom on re-learning doing all of those types of calculations with the Metric System?


Also, I can flat out state, that I have NEVER understood why America didn't go Metric. It makes WAY, WAY more sense.
Must have been an "unofficial" decision by various, stuck in the mud, backwards thinking, corporate magnates, back in the '70's or some such thing. Ugh!


So, yeah, any tips on learning Metric's for Engineering, would be GREATLY appreciated!

[valhalla360]

Originally Posted by UNCIVILIZED

Having been schooled as an Engineer (using the English/American System), does anyone have some words of wisdom on re-learning doing all of those types of calculations with the Metric System?


Also, I can flat out state, that I have NEVER understood why America didn't go Metric. It makes WAY, WAY more sense.
Must have been an "unofficial" decision by various, stuck in the mud, backwards thinking, corporate magnates, back in the '70's or some such thing. Ugh!


So, yeah, any tips on learning Metric's for Engineering, would be GREATLY appreciated!

I believe per the law, we have been metric since the Carter days.

No special learning needed to switch to metric. As long as you understand the underlying concepts, it's simple.

As to why...I worked for a state DOT. There was a huge push to convert to metric. Plans were redone, we had to rewrite all the manuals and guidelines. Took about 5yrs to convert over. After the conversion was complete and in place for a few years, what they found was the contractors were taking the plans and having someone convert them all back to english units as all thier equipement and the existing facilities they were working on were based on english units. Eventually, they realized what a waste it was and it was driving up bid prices, so they switched it all back to english units. No conspiracy, just simpler to use what everyone was comfortable with.

[StuM]

Originally Posted by valhalla360

My point is a lot of these issues I'm coming across seem to be tied to the relative ease of converting units. It's so easy to just shift a decimal point without an intuitive sense of what you did that these mistakes are creeping in.

That's because of electronic calculators. Bring back the slide rule - it forces you into an awareness of orders of magnitude

[carstenb]

Originally Posted by UNCIVILIZED

Having been schooled as an Engineer (using the English/American System), does anyone have some words of wisdom on re-learning doing all of those types of calculations with the Metric System?


Also, I can flat out state, that I have NEVER understood why America didn't go Metric. It makes WAY, WAY more sense.
Must have been an "unofficial" decision by various, stuck in the mud, backwards thinking, corporate magnates, back in the '70's or some such thing. Ugh!


So, yeah, any tips on learning Metric's for Engineering, would be GREATLY appreciated!

If my memory serves me correctly (might not), then the US army converted in the early 70's, or at least started to convert. They quit when the US auto industry refused, saying they would have to retool every factory they had in the country.

This was back when every fourth job in the US was either directly or indirectly dependent on the auto industry. "what's good for General Motors is good for the country" as someone once noted.

I would be relativey easy for the US to switch today sonce there are any number of metric sized bolts, nuts screws etc already in use.

I was brought up in the american system, but having lived in europe for many years now, I have no hesitation using the metric system or the US system. It doesn't matter to me.

[K_V_B]

Originally Posted by valhalla360

English units are typically based on the human body. While they have been locked down for consistency, you have a built in set of references (ie: an inch is around the distance from the tip of your thumb to the first joint. A meter was originally intended to be 1/10,000 the distance from the earths pole to the equator. I believe the latest is based on how far light travels during a specified number of vibrations of a particular type of atom. Which one is more intuitive?

We've been there before. That's really a pretty silly argument. One can easily say that the metric system is also based on the human body. The metre is for example the length of my stride. I am trained as a civil engineer, and used to survey land just by walking.
The reason why the meter now has a definition that does not depend on the existence of any physical object has a reason. The English once lost their standards in a fire. It took them more then 10 years before they had a proper feet standard again.
Eventually it was decided to just define Yard, Foot and Inch in terms of the metric system. So the official legal definition of "one yard" is now 0.9144m. Stop pretending that this is somehow "intuitive", or "based on the human body".

[valhalla360]

Originally Posted by K_V_B

We've been there before. That's really a pretty silly argument. One can easily say that the metric system is also based on the human body. The metre is for example the length of my stride. I am trained as a civil engineer, and used to survey land just by walking.
The reason why the meter now has a definition that does not depend on the existence of any physical object has a reason. The English once lost their standards in a fire. It took them more then 10 years before they had a proper feet standard again.
Eventually it was decided to just define Yard, Foot and Inch in terms of the metric system. So the official legal definition of "one yard" is now 0.9144m. Stop pretending that this is somehow "intuitive", or "based on the human body".

No a meter is not the length of your stride (unless you are like 7' tall). I'm also a civil engineer and pace off distances. When pacing, I use an exagerated stride and it's only 3' and I'm 6'2".

The mile is defined as thousand paces (left foot, right foot). That was the original definition (again based on the human body). The Romans found that stride is around 2.64'. Not even close to the meter which is 3.28'. That's a 25% error.

Yes, they have standardized the english units...just like they have had to update the standards for metric units.

There are pros and cons to each. One of the pro's for english units is they are more intuitive.

[Ribbit]

I wasn't bothered either way (metric vs imperial, other than considering that metric was far from a panacea, and am aware that it can be positively dangerous to rely on it in many applications - and not just in heavy engineering either) until I went I went back to College again a few years back. There were two others of my generation on the IT Course I was doing, and we all came to the conclusion that metric has been nothing but an absolute disaster, for the maths capabilities of what are otherwise, extremely bright youngsters. It would appear that metric is far too easy, and doesn't help young minds to develop properly with maths, because it doesn't stretch them. I can't imagine people taught in metric, being able to do long division, like I was at the age of 5 for example (in my rural village school, all my fellow 5 year olds were also doing long division)

For background, each of us three had been outside of Education, for 30 years plus. So very, very rusty, and frankly, none of us should have been able to compete with the youngsters that hadn't left Education, as a result. None of us three were maths 'geniuses' when at school or at College/Uni from school.

Now the best insight into the differences between us, was the maths testing that comprised 10 x 2 hours exams, prior to even starting the Java programming Course.

These 10 exams ranged from simple, starter maths, to Scientific. Like the other two of my generation, I had finished the first test 'twice' within 3 minutes. Finished and checked once.

Almost all of the youngsters were still scribbling away, at the end of the two hour period. The lecturer told us if we were finished and happy with what we had done, with future tests we could hand our papers in and leave the exam room at any time.

Most of the rest of the tests, the three of us were finished in under 5 minutes and exiting the room, and most of the youngsters were leaving the exam room at the end of the two hours.

The last exam took under 12 minutes for the three of us. The final results, out of a maximum of 1,000 (10 tests at 100 marks per test), we each got 999/1,000. We dropped a point because we forgot that even if requested NOT to put down your method in the question, you always put down your method (we each gave correct answers otherwise). None of the youngsters came remotely close to us, the best had just under 900/1,000.

Now I cannot emphasise strongly enough, how bright these youngsters were, and what an absolute privilege it was to be on a Course with them.

But the three of us were absolutely disgusted at how badly Education is letting them down (and this is now true across the whole of the EU, and pretty much the rest of the World, because the same techniques and format are being used, from school entry, with the exact same Higher Education Courses, pretty much World wide).

The youngsters deserve far, far better, and to me we need to go back to pre-WW1 Education principles and standards (Education was already proving to be on the wrong Course by the late 1920's, because Buckminster Fuller was already noticing a substantial drop in standards by then, and he was railing about it in one of his books - and things have become much, much worse, since then).

So for the benefit of the kids, I think we should have the two systems side by side, but especially during the school years, and in Society at large, priority should be given to Imperial.

12d to the shilling, 20 shillings to the £; 16ozs to the pound, 112lb to the cwt, 20 cwt to the ton; 3ft to the yd, 1,760 yds to the mile; pints, gallons, etc., are a maths education all on their own, and NOBODY used to struggle to work out change at a cash register, and NOBODY was in the position of not knowing the answer on a pocket calculator wasn't 'ballpark', until we went metric.

The lie sold to us was that computers needed metric, when the reality is, they don't.

We need to undo this inexcusable mess we have created, otherwise I tell you this, we are now getting in the position of being unable to do anything at all, with the loss of expertise, we are presently experiencing (Worldwide). There are no free lunches with this, and the final bill could well turn out to be one we find that is unpayable.

[carstenb]

Originally Posted by Ribbit

I wasn't bothered either way (metric vs imperial, other than considering that metric was far from a panacea, and am aware that it can be positively dangerous to rely on it in many applications - and not just in heavy engineering either) until I went I went back to College again a few years back. There were two others of my generation on the IT Course I was doing, and we all came to the conclusion that metric has been nothing but an absolute disaster, for the maths capabilities of what are otherwise, extremely bright youngsters. It would appear that metric is far too easy, and doesn't help young minds to develop properly with maths, because it doesn't stretch them. I can't imagine people taught in metric, being able to do long division, like I was at the age of 5 for example (in my rural village school, all my fellow 5 year olds were also doing long division)

For background, each of us three had been outside of Education, for 30 years plus. So very, very rusty, and frankly, none of us should have been able to compete with the youngsters that hadn't left Education, as a result. None of us three were maths 'geniuses' when at school or at College/Uni from school.

Now the best insight into the differences between us, was the maths testing that comprised 10 x 2 hours exams, prior to even starting the Java programming Course.

These 10 exams ranged from simple, starter maths, to Scientific. Like the other two of my generation, I had finished the first test 'twice' within 3 minutes. Finished and checked once.

Almost all of the youngsters were still scribbling away, at the end of the two hour period. The lecturer told us if we were finished and happy with what we had done, with future tests we could hand our papers in and leave the exam room at any time.

Most of the rest of the tests, the three of us were finished in under 5 minutes and exiting the room, and most of the youngsters were leaving the exam room at the end of the two hours.

The last exam took under 12 minutes for the three of us. The final results, out of a maximum of 1,000 (10 tests at 100 marks per test), we each got 999/1,000. We dropped a point because we forgot that even if requested NOT to put down your method in the question, you always put down your method (we each gave correct answers otherwise). None of the youngsters came remotely close to us, the best had just under 900/1,000.

Now I cannot emphasise strongly enough, how bright these youngsters were, and what an absolute privilege it was to be on a Course with them.

But the three of us were absolutely disgusted at how badly Education is letting them down (and this is now true across the whole of the EU, and pretty much the rest of the World, because the same techniques and format are being used, from school entry, with the exact same Higher Education Courses, pretty much World wide).

The youngsters deserve far, far better, and to me we need to go back to pre-WW1 Education principles and standards (Education was already proving to be on the wrong Course by the late 1920's, because Buckminster Fuller was already noticing a substantial drop in standards by then, and he was railing about it in one of his books - and things have become much, much worse, since then).

So for the benefit of the kids, I think we should have the two systems side by side, but especially during the school years, and in Society at large, priority should be given to Imperial.

12d to the shilling, 20 shillings to the £; 16ozs to the pound, 112lb to the cwt, 20 cwt to the ton; 3ft to the yd, 1,760 yds to the mile; pints, gallons, etc., are a maths education all on their own, and NOBODY used to struggle to work out change at a cash register, and NOBODY was in the position of not knowing the answer on a pocket calculator wasn't 'ballpark', until we went metric.

The lie sold to us was that computers needed metric, when the reality is, they don't.

We need to undo this inexcusable mess we have created, otherwise I tell you this, we are now getting in the position of being unable to do anything at all, with the loss of expertise, we are presently experiencing (Worldwide). There are no free lunches with this, and the final bill could well turn out to be one we find that is unpayable.

This isn't the fault of the metric system, this is the fault of pocket calcualtors and excel spreadsheets.

No does arithmetic in their heads anymore because they don't need to. Even cash registers at stores tell the clerks what to give as change.

[alctel]

I am finding incredibly difficult to find metric drill bits of any kind, let alone the colbalt and hole saws I need in Canada. It's driving me up the wall.

I'm trying to build a wind vane and all the measurements are in metric.

[hellosailor]

"and the US itself has two definitions of what a "feet" is "
Uh-huh, sure we do. And somehow, after all these years, I've only found one definition and our National Bureau of Standards seems to have missed the same memo.
By all means, please, tell us all what "feet" is.


As to an engineering firm "commonly" making one or two decimal point mistakes in their renderings...that would be a tremendous liability issue and reason to terminate the contract unless some quality control group was brought in to assume the liability.


Or perhaps, some optometrists and a drug testing lab.

[Mirage35]

Originally Posted by carstenb

This isn't the fault of the metric system, this is the fault of pocket calcualtors and excel spreadsheets.

No does arithmetic in their heads anymore because they don't need to. Even cash registers at stores tell the clerks what to give as change.

Even though I told myself I wouldn't, I'm going to have to weigh in again with my own observations:

When I started in engineering, we did our calculations with slide rules (remember those?) which, for those who don't know, give you the numbers but no decimal place. This forces you to do an estimate before calculation so that you know if you're looking for an answer that is, for example, "about 200" or about "2 million". You then do the calculation and place the point accordingly.

A few years later when I was marking engineering assignments, I saw students giving answers that were off by orders of magnitude, because they were no longer required to take that first step of understanding what answer is expected. The would just write down what the calculator gave them without thinking about it.

So, I don't believe one system is inherently more intuitive than the other, just that it's important regardless of which you're using to understand the problem and expected result before diving in.

[hellosailor]

I also remembered my slide rule, but suspect that kind of decimal error to be rare these days. Oh wait, perhaps North Korean Hackers are distributing a "randomly move the decimal point" in bootleg spreadsheet software?(VBG)


My physics professor used to yell at me for providing four decimal places on answers, insisting the slide rule was only good for three with interpolation. I said no, if you used the inverted scales and just kept going, you only had to interpolate once, at the very end, and that made the extra digit very simple to carry. He left me alone after that.


But then again, we didn't have any North Koreans in the class. Or Chinese communists, Iraqi's, or ISIS.


Debugging a slide rule usually just required a screwdriver.