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Metric Or Imperial?  
User currently offlinebristolflyer From United Kingdom, joined May 2004, 2270 posts, RR: 0
Posted (1 year 7 months 1 week 3 days 7 hours ago) and read 6406 times:

I was taught the metric (mm) system at school in England, now I live in the US which mostly uses the imperial (inches) system. I can see a good reason for using both - eg in construction everyone is used to 2x4, 2x6 etc and multiples of 4' for sheet materials. But when it comes to finer tolerance stuff I definitely prefer metric. When you get down to stuff that's 1/2" or less the metric system seems way easier.

I was listening to NPR today and there was an American designer talking about designing cell phones, he was talking in mm. What do the big electronics manufacturers use? I feel that describing something as '2mm' is was easier than '3/32'.

Anyone have preferences, and why?


Fortune favours the brave
155 replies: All unread, showing first 25:
 
User currently offlineDreadnought From United States of America, joined Feb 2008, 8711 posts, RR: 24
Reply 1, posted (1 year 7 months 1 week 3 days 6 hours ago) and read 6381 times:

I prefer metric, but living in the US I have given up converting people. But I think the US will one day come around.


Veni Vidi Castratavi Illegitimos
User currently offlinelewis From Greece, joined Jul 1999, 3592 posts, RR: 5
Reply 2, posted (1 year 7 months 1 week 3 days 6 hours ago) and read 6377 times:

I prefer metric. 100 cm in a meter, 1000g in a kg. The scale of measurements makes more sense. In imperial, there is no round conversion between units and their sub-units (inches vs feet vs miles or ounces vs gallons).

I do prefer temperatures in F over C though. Even though C makes more sense in science (0 freezing point, 100 boiling point), the F scale is much wider and offers more accurate temperature readings for everyday use. In order to achieve that, we would have to use decimals in C when talking about the weather.


User currently offlinevikkyvik From United States of America, joined Jul 2003, 9398 posts, RR: 27
Reply 3, posted (1 year 7 months 1 week 3 days 6 hours ago) and read 6376 times:
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Metric is WAY better and easier.

But, my day-to-day life is governed by Imperial.



"Two and a Half Men" was filmed in front of a live ostrich.
User currently offlineokie From United States of America, joined Jul 2003, 2851 posts, RR: 3
Reply 4, posted (1 year 7 months 1 week 3 days 6 hours ago) and read 6367 times:

I think Pres Carter started the shift near 40 yrs ago with a goal of being transitioned by 2000. (30yrs)
Now it has been close to 40 years.

40 years ago the US was probably the major exporter and importer of manufactured goods world wide and had pretty much all the influence as far as manufactured goods were concerned.

The problem with switching to the metric system for the US was at that time there was no real supply chain or manufacturing chain in existence for metric machine tools ie drills, taps, dies, calipers etc. The only metric hand tools available were very low quality import at exorbitant prices due to low volume of sales.

Right now there is no push to change to metric since tool and machine manufacturers get to sell both (double the sales)

The same can be claimed for IEC/Metric vs NEMA/US electric motors.

An interesting deal that I ran into, a company that I worked for bought a piece of equipment from a "world" company that different sections shipped from different countries. A US section an UK section and one section from Denmark.
Something as simple as chain was a night mare US (inch pitch) BS British Std. (inch pitch but different width) and Metric.

Right now we run into issues with electric motors designed for both 50 hz and 60 hz.

So as long as manufacturers are doubling machine tool and hand tool sales there will be no major shift.

Okie


User currently offlinetrvyyz From Canada, joined Oct 2004, 1369 posts, RR: 10
Reply 5, posted (1 year 7 months 1 week 3 days 6 hours ago) and read 6349 times:

I work in the EMI/EMC field and I sometimes use US standards.
Here is the MIL standard of US, if you scroll down a few pages and see the diagrams, the distances are all metric
http://snebulos.mit.edu/projects/reference/MIL-STD/MIL-STD-461F.pdf

This is from FCC website, all distances are in meters
http://ecfr.gpoaccess.gov/cgi/t/text...node=47:1.0.1.1.16.2.234.6&idno=47


User currently offlineB777LRF From Luxembourg, joined Nov 2008, 1208 posts, RR: 3
Reply 6, posted (1 year 7 months 1 week 3 days 5 hours ago) and read 6345 times:

Quoting bristolflyer (Thread starter):
I can see a good reason for using both - eg in construction everyone is used to 2x4, 2x6 etc and multiples of 4' for sheet materials.

Everyone that comes from a country where inches was or is the traditional unit of measurement. I've got mates who own companies in the building industry, and they wouldn't know what a 4x4 is unless you wack them over the head with it. Houses, furniture, kitchens - you name it, it's all built to metric measurements in most of the world. They do know if they'll need a 10 or 12 wrench, but I don't think they'll even know that's an imperial measurement.

As indicated above, where inches will be really, really, difficult to replace is in industries where imperial measurements is an organic part, such as the tools industry. Aviation is another such example, with every single (western built) aircraft in existence is based on inches.

So while it will be very difficult indeed to introduce a wholesale transition to the metric system, for all "civilian" applications things are far less complicated and makes a lot more sense. Once you've gotten used to it the metric system is simpler, more logical, offers seamless transitions between weight, distance and volume, and is much easier to work with.



From receips and radials over straight pipes to big fans - been there, done that, got the hearing defects to prove
User currently offlineKFLLCFII From United States of America, joined Sep 2004, 3288 posts, RR: 31
Reply 7, posted (1 year 7 months 1 week 3 days 4 hours ago) and read 6303 times:

All hardware on my Dodge truck is to metric standard, but fluid capacities and anything else that needs to be measured or torqued is listed in both metric and imperial. It doesn't bother me one bit.

Nor does it bother me that our sodas are measured in liters, yet our milk is measured in quarts or gallons. Liquors come in 750ml, but I can get a quart (or pint) of beer.

Common ammunition cartridges include .22, 5.56mm, .25, 7.62mm, .357, 9mm, .40, 10mm, and .45.

There are 60 seconds in a minute (time or angle), 60 minutes in an hour/degree, 24 hours in a day, 365 (1/4) days in a year, and 360 degrees in a circle, yet most of the world doesn't seem to have a problem remembering this...until the metric community conveniently forgets and preaches that all measurements could be simplified into a base of ten.

Just like languages, it's what we're born and raised with. I wouldn't expect the entire literate world to convert to one spoken language because the language may be "easier" in practice, nor would I expect each and every standard and measurement to become uniform among seven billion people. It is much easier, however, to perfect the conversion of units from one system to another...And in this day and age, with the right conversion factor in hand (with or without the use of technology), there is simply no excuse for a conversion failure. It's not an art, it's a science.

Any measurement is useless without a unit, and any attempt to process measurements of dissimilar units without converting is not a failure of the system, but a failure of the operator. Plain and simple.



"About the only way to look at it, just a pity you are not POTUS KFLLCFII, seems as if we would all be better off."
User currently offlinelewis From Greece, joined Jul 1999, 3592 posts, RR: 5
Reply 8, posted (1 year 7 months 1 week 3 days 4 hours ago) and read 6287 times:

Quoting KFLLCFII (Reply 7):
There are 60 seconds in a minute (time or angle), 60 minutes in an hour/degree, 24 hours in a day, 365 (1/4) days in a year, and 360 degrees in a circle, yet most of the world doesn't seem to have a problem remembering this...until the metric community conveniently forgets and preaches that all measurements could be simplified into a base of ten.

Just like languages, it's what we're born and raised with.

That makes sense but when I wanted to get a grasp of imperial units, asking questions about it proved to be hard too. Many people will have to think very hard if I ask them "how many fl. ounces in a gallon?", "how many ounces in a pound?" or "how many inches in a mile?". Some did not even know, and I am talking about educated people. With metric, even if you don't know from the top of your head, it is much easier to figure out. I have been using imperial for the past couple of years and although I get it, it is not as convenient as metric, purely from a conversion standpoint.

Time is a whole different story. We deal with it literally every second of our lives so it is embedded in our minds. Having said that, if you take physics as an example, making conversions that contain time is much harder than just converting distances or weights just because of the lack of common factors.


User currently offlineKen777 From United States of America, joined Mar 2004, 8045 posts, RR: 8
Reply 9, posted (1 year 7 months 1 week 3 days 3 hours ago) and read 6266 times:

Imperial. Absolutely no need for the US to change.

First, the cost of a conversion is absolutely unnecessary. Every speed limit sign in the US changed just to "be metric"? Stupid.

And that is not the only cost. When Australia was converting my main argument was that the government would increase petrol taxes a penny a liter instead of a penny a gallon. Not my cuppa.

Reality is that those fields that need to use metric are already metric. You see that in medicine, but even there we see some losses. Imperial temperatures are more precise than metric, especially when looking at change.

Quoting KFLLCFII (Reply 7):
There are 60 seconds in a minute (time or angle), 60 minutes in an hour/degree, 24 hours in a day, 365 (1/4) days in a year, and 360 degrees in a circle, yet most of the world doesn't seem to have a problem remembering this...

That's because nature isn't metric.  


User currently offlinefr8mech From United States of America, joined Sep 2005, 5098 posts, RR: 12
Reply 10, posted (1 year 7 months 1 week 3 days 3 hours ago) and read 6259 times:

I really wish we had made the move over back in the 70's. Of course, we would still be dealing with a dual system due to legacy installation, but I can live with that.

I teach my kids both systems. My daughter was having a hard time with it, but my son is getting it.

Quoting bristolflyer (Thread starter):
2x4, 2x6 etc and multiples of 4' for sheet materials.

How do they build homes in Metric nations?



When seconds count...the police are minutes away. Never leave your cave without your club.
User currently offlinebristolflyer From United Kingdom, joined May 2004, 2270 posts, RR: 0
Reply 11, posted (1 year 7 months 1 week 3 days 3 hours ago) and read 6250 times:

Quoting B777LRF (Reply 6):
Everyone that comes from a country where inches was or is the traditional unit of measurement. I've got mates who own companies in the building industry, and they wouldn't know what a 4x4 is unless you wack them over the head with it. Houses, furniture, kitchens - you name it, it's all built to metric measurements in most of the world.

That's interesting. The irony about the imperial system in the construction industry is that a 2" x 4" doesn't actually measure 2" x 4" - so converting wouldn't be that much of a chore!

Anyone know what units show on airplane drawings?



Fortune favours the brave
User currently offlineKen777 From United States of America, joined Mar 2004, 8045 posts, RR: 8
Reply 12, posted (1 year 7 months 1 week 3 days 3 hours ago) and read 6242 times:

Quoting bristolflyer (Reply 11):
That's interesting. The irony about the imperial system in the construction industry is that a 2" x 4" doesn't actually measure 2" x 4" - so converting wouldn't be that much of a chore!

I can remember reading some years back that metric was easier for estimating construction costs, especially in preparing the bill of materials. The house we built in PER was "metric, but when I built a pergola I had to use Imperial as shade cloth was still 36" wide. I also believe that carpets were imperial (12' wide) as well.


User currently offlineQuokkas From , joined Dec 1969, posts, RR:
Reply 13, posted (1 year 7 months 1 week 3 days 2 hours ago) and read 6233 times:

Quoting Ken777 (Reply 9):
Imperial. Absolutely no need for the US to change.

Being brought up with both, I do like the quirkiness of the Imperial system: fathoms, cables and nautical miles. Then 16 oz = 1lb, 14lb = 1st, 8st = 1cwt, 20cwt = 1 ton. But the US cwt is only 100lb so the ton is only 2,000lb (the so-called short ton) while the Imperial ton is 2,240lb (the so-called long ton).

So even when comparing Imperial to metric, we need to remain aware of the differences between British and US usage as the measurements will not always be the same. It is not a problem when comparing length and area, but there are differences for capacity and mass. While an Imperial gallon is the equivalent of 4.54609 litres, a US gallon is only 3.78541 litres.

Now, if only we could get back to guineas, pounds, shillings and pence. How wonderful tuppence three-farthing sounds.  


User currently offlinerwessel From United States of America, joined Jan 2007, 2238 posts, RR: 2
Reply 14, posted (1 year 7 months 1 week 3 days 2 hours ago) and read 6235 times:
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Quoting Ken777 (Reply 9):
Quoting KFLLCFII (Reply 7):
There are 60 seconds in a minute (time or angle), 60 minutes in an hour/degree, 24 hours in a day, 365 (1/4) days in a year, and 360 degrees in a circle, yet most of the world doesn't seem to have a problem remembering this...

That's because nature isn't metric.

Only one of those (days per year) actually has anything to do with nature. The subdivisions of a day or circle are completely arbitrary (although a fair case can be made that the "natural" subdivisions of a circle should be 2*pi radians, or something related to that, although that would probably be less practical).

Quoting bristolflyer (Reply 11):
That's interesting. The irony about the imperial system in the construction industry is that a 2" x 4" doesn't actually measure 2" x 4" - so converting wouldn't be that much of a chore!

Even considering nominal sizes, a 5x10 (centimeters) would be only 1.6% off a nominal 2x4. Considering actual sizes, the difference would pretty much be within the manufacturing tolerances.


And folks - the U.S. doesn't use Imperial Units, it uses Standard Units (or more formally, "U.S. Customary Units").


User currently offlineStuckInCA From United States of America, joined Oct 2005, 1922 posts, RR: 0
Reply 15, posted (1 year 7 months 1 week 3 days 2 hours ago) and read 6227 times:

Quoting bristolflyer (Thread starter):
But when it comes to finer tolerance stuff I definitely prefer metric. When you get down to stuff that's 1/2" or less the metric system seems way easier.

I've been doing precision mechanical design (I worry about nanometers and microns) for many years and have had jobs where we did design in inches and jobs where we did it in metric (as in my current position). I really think it's just a matter of what you're used to. If you work in inches, it takes no time to have a really good sense for what .001" is and that, for example, 1/64" is .015625. It becomes automatic. Neither system really stands out as easier in a meaningful way. That said, I prefer metric.


User currently offlineRevelation From United States of America, joined Feb 2005, 11929 posts, RR: 25
Reply 16, posted (1 year 7 months 1 week 3 days 2 hours ago) and read 6214 times:

Quoting bristolflyer (Thread starter):
I was listening to NPR today and there was an American designer talking about designing cell phones, he was talking in mm. What do the big electronics manufacturers use? I feel that describing something as '2mm' is was easier than '3/32'.

From what I've see, stuff on circuit boards themselves are done in metric units, but quite often the enclosures and mounting hardware are done in US. For instance, we still talk of the 19" rack in our lab area. I have noticed that the interior rails of many of the newer racks are adjustable.

Of course NASA and other organizations such as Disney have been caught out due to metric/US conversion errors:

http://www.mentalfloss.com/blogs/archives/68051

http://chemwiki.ucdavis.edu/Analytic...ric%2F%2FEnglish_Conversion_Errors

Quoting Ken777 (Reply 9):
Quoting KFLLCFII (Reply 7):
There are 60 seconds in a minute (time or angle), 60 minutes in an hour/degree, 24 hours in a day, 365 (1/4) days in a year, and 360 degrees in a circle, yet most of the world doesn't seem to have a problem remembering this...

That's because nature isn't metric.

Many computer designs of the 1950s and 1960s were binary based but with 36 bit words. That's because when IBM designed the 701 and 704 (http://en.wikipedia.org/wiki/IBM_704) they decided that 72 bits of precision were needed to do the math that their customers wanted to do. This led to the 6 bit byte, the 36 bit word, and the 72 bit double-word.

The System/360 was named because of 360 degrees in a circle, but interestingly enough it was/is a 32 bit machine.



Inspiration, move me brightly!
User currently offlinerwessel From United States of America, joined Jan 2007, 2238 posts, RR: 2
Reply 17, posted (1 year 7 months 1 week 3 days 2 hours ago) and read 6194 times:
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Quoting Revelation (Reply 16):
Many computer designs of the 1950s and 1960s were binary based but with 36 bit words. That's because when IBM designed the 701 and 704 (http://en.wikipedia.org/wiki/IBM_704) they decided that 72 bits of precision were needed to do the math that their customers wanted to do. This led to the 6 bit byte, the 36 bit word, and the 72 bit double-word.

The System/360 was named because of 360 degrees in a circle, but interestingly enough it was/is a 32 bit machine.

It was more the single precision (36 bit) floats that were useful. The transition to S/360 with 32 bit singles (which were a bit too short) caused all sorts of grief, and caused many people to recode with doubles (which were more of an exception in earlier times).

And the System/360 ("all around", as in both commercial and scientific applications) had a embedded variant, used in a number of aviation application (including the B-52, F-15 and Space Shuttle), named the "System/4 Pi", which is the number of Steradians in a sphere (more or less the equivalent of 360 degrees for a sphere).


User currently offlinestealthz From Australia, joined Feb 2005, 5609 posts, RR: 45
Reply 18, posted (1 year 7 months 1 week 3 days 2 hours ago) and read 6191 times:
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Quoting rwessel (Reply 14):
And folks - the U.S. doesn't use Imperial Units, it uses Standard Units (or more formally, "U.S. Customary Units").

And sinificantly different to imperial measures in some areas.

A US gallon is somwhat smaller than an Imperial one based on a US pint being a touch over 16 fl/oz whereas an Imperial pint is 20 fl/oz.
And ask most Americans how many pounds in a ton??



If your camera sends text messages, that could explain why your photos are rubbish!
User currently offlineRevelation From United States of America, joined Feb 2005, 11929 posts, RR: 25
Reply 19, posted (1 year 7 months 1 week 3 days 1 hour ago) and read 6170 times:

Quoting rwessel (Reply 17):

It was more the single precision (36 bit) floats that were useful. The transition to S/360 with 32 bit singles (which were a bit too short) caused all sorts of grief, and caused many people to recode with doubles (which were more of an exception in earlier times).

Interesting. I hadn't thought of this since I tend to work in network and operating system spaces, but I suppose the transition to 64 bit computing has made a lot of these 'dusty deck' programs go really fast.

In particular, the AMD64 mode that Intel has cloned as well also increased the number of general purpose registers as well, so the combination is quite helpful for that type of code.

This presumes a lot of those programs made the transition to IEEE floating point, which from what I understand, can be just as problematic. This caused much grief to a program I worked on when I was an IBMer in the 80s.

Just read that the fastest commercially offered CPU in terms of clock rate is now the latest IBM 360 descendent, running at 5.5 GHz, so if you want your IBM floats you can have them!

Quoting rwessel (Reply 17):
And the System/360 ("all around", as in both commercial and scientific applications) had a embedded variant, used in a number of aviation application (including the B-52, F-15 and Space Shuttle), named the "System/4 Pi", which is the number of Steradians in a sphere (more or less the equivalent of 360 degrees for a sphere).

I had heard of AP-101 in the Space Shuttle context, but I was not aware of the family name System/4 Pi.

Ahh more cruft to file away in the ol' memory banks!  



Inspiration, move me brightly!
User currently offlineWrenchBender From Canada, joined Feb 2004, 1779 posts, RR: 9
Reply 20, posted (1 year 7 months 1 week 3 days 1 hour ago) and read 6162 times:

Quoting Ken777 (Reply 9):
Imperial. Absolutely no need for the US to change.

I wouldn't mind so much if the US actually used IMPERIAL instead of the bastardised US fluid system. A Gallon is 4.54 L not 3.78 L.

WrenchBender



Silly Pilot, Tricks are for kids.......
User currently offlineKen777 From United States of America, joined Mar 2004, 8045 posts, RR: 8
Reply 21, posted (1 year 7 months 1 week 3 days 1 hour ago) and read 6151 times:

Quoting WrenchBender (Reply 20):

Quoting Ken777 (Reply 9):
Imperial. Absolutely no need for the US to change.

I wouldn't mind so much if the US actually used IMPERIAL instead of the bastardised US fluid system. A Gallon is 4.54 L not 3.78 L.

You do realize that if the US was to move to the UK Gallon all of our cars would get immediate improvements in milage. My old Caddy might hit 30 MPG on the interstates.  


User currently offlineWrenchBender From Canada, joined Feb 2004, 1779 posts, RR: 9
Reply 22, posted (1 year 7 months 1 week 3 days ago) and read 6132 times:

Quoting Ken777 (Reply 21):
You do realize that if the US was to move to the UK Gallon all of our cars would get immediate improvements in milage. My old Caddy might hit 30 MPG on the interstates.

Ahhhhh, the new science "How to use statistics to lie like a politician"  

WrenchBender



Silly Pilot, Tricks are for kids.......
User currently offlineStarAC17 From Canada, joined Aug 2003, 3334 posts, RR: 9
Reply 23, posted (1 year 7 months 1 week 3 days ago) and read 6132 times:

Quoting Ken777 (Reply 9):
First, the cost of a conversion is absolutely unnecessary. Every speed limit sign in the US changed just to "be metric"? Stupid.

For 1 dimensional units it is no big deal and a speed limit is because it is a rate there is only the value between km and miles that needs to be considered.

The biggest annoyances are with areas and volumes where converting a square foot to a square meter or a cubic foot to a cubic meter is a big challenge. As an engineer converting something like PSI or PSF to KPa or MPa takes a long time.

The biggest value as an engineer to the metric system is based on values of 10 such as that 1km is 1000m, 1m is 1000mm, 1mm is 1um etc.* It increases productivity.

Whereas 1 mile is 5280 ft, 1yd is 3ft, 1 ft is 12 inches. and there is no easy way to convert values.

*um is the greek symbol used for micro which I have no idea how to enter.



Engineers Rule The World!!!!!
User currently offlinerwessel From United States of America, joined Jan 2007, 2238 posts, RR: 2
Reply 24, posted (1 year 7 months 1 week 3 days ago) and read 6128 times:
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Quoting Revelation (Reply 19):
In particular, the AMD64 mode that Intel has cloned as well also increased the number of general purpose registers as well, so the combination is quite helpful for that type of code.

64-bit mode has been a mixed bag in terms of performance on most platforms. Obviously it enables more memory, which, for some applications, can be a considerable benefit. But the larger code and longer pointers tend to have a significant (~10%) negative impact on performance, mainly due to increased cache/memory bandwidth pressures. x86-64 is a more complex case - 64 bit code is bulkier due to both the increases in pointer sizes, and increases in code size (lots of REX prefixes lying about), so it tends to be slower, but the extra registers help performance. Most of the time it's about a wash. There's a fairly active effort to define a set of APIs for Linux that uses 32 bit pointers (hence the whole program would have still to fit in 4GB), but it could use the extra regs.

Quoting Revelation (Reply 19):
This presumes a lot of those programs made the transition to IEEE floating point, which from what I understand, can be just as problematic. This caused much grief to a program I worked on when I was an IBMer in the 80s.

S/360 has supported binary IEEE float since the G4 or G5 generation of 9672s in the mid/late nineties. Decimal IEEE float support has been added more recently (so the machines now support three formats).

Binary IEEE float has its issues, but far, far, fewer than old S/360 hex float. Part of the reason IBM did floating hex was to make up for the reduced precision from the transition from 36 to 32 bit floats. Unfortunately this makes the precision effectively wobble, based on what the high digit of the number was, which actually made things worse (in essence, the number of bits of precision wobbles between 21 and 24). The IEEE (single) format has a solid 24 bits (because of the implied leading one bit). These compare to 27 bits in the old 36 bit formats.


User currently offlinekl671 From Canada, joined Jul 2005, 141 posts, RR: 0
Reply 25, posted (1 year 7 months 1 week 3 days ago) and read 6254 times:

Quoting bristolflyer (Thread starter):
I can see a good reason for using both

Car tire manufacturers apparently share your point of view. Tire widths are measured in millimeters while the diameter is in inches.

I am sure there is a good reason for this but I can't think of one!


User currently offlineRevelation From United States of America, joined Feb 2005, 11929 posts, RR: 25
Reply 26, posted (1 year 7 months 1 week 3 days ago) and read 6237 times:

Quoting rwessel (Reply 24):
S/360 has supported binary IEEE float since the G4 or G5 generation of 9672s in the mid/late nineties. Decimal IEEE float support has been added more recently (so the machines now support three formats).

Yep, as above, that was probably a decade too late for me. I worked for IBM on a project to put AIX on the mainframe of the time which was ESA. The idea was that it was quite a substantial machine for the time in terms of memory and I/O capacity and throughput (despite its cost) and could be used as application server, file server and/or number cruncher. All three were problematic: a) porting applications to it was not easy, b) it wasn't that stable and reboots took a long time so it was problematic as a file server, and c) the lack of IEEE float drove away the number crunching audience. The meeting where our university partners (who had been given mainframes by IBM) spelled this all out to us was one of the most depressing in my career.

Fast forward 15 or so years and you have SUSE and RHEL on the mainframe, which fixed the application issue (as much as it can be fixed via linux), as well as the stability issues. As you note, all the hardware they support has the IEEE float so that problem went away too. I think one of the early linux ports supported the non-IEEE floats, but shortly decided it wasn't worth the effort. A key enabler was getting GCC to produce decent code for the IBM mainframes, which was no easy task. Google will pull up a few papers on the topic should you be interested in reading about it. I suppose it says something about me that I read those papers?  

Unfortunately for IBM by the time many of these things came together the mainframe's advantage in memory and I/O throughput and capacity weren't there especially on a price/performance basis. However, they are still plugging the product: they had a decent sized booth at the Red Hat Summit I attended in Boston this summer.



Inspiration, move me brightly!
User currently offlinestealthz From Australia, joined Feb 2005, 5609 posts, RR: 45
Reply 27, posted (1 year 7 months 1 week 2 days 23 hours ago) and read 6287 times:
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Quoting kl671 (Reply 25):
I am sure there is a good reason for this but I can't think of one!

Tyre widths were originally in inches, when radial tyres started to replace cross(bias)-ply tyres a way of differentating them was required, measuring the width in mm seemed an easy way to do this, a concept also perhaps driven by the fact the first company to introduce radial automotive tyres was Michelin from France(even though radial tyres were invented by an American in 1915)
In the '70s Dunlop introduced the Denovo, a run flat tyre that required special rims quite different to a normal wheel so they made them in different sizes and the rim diam. was measured in mm again to differentiate them from conventional wheels.

Quoting rwessel (Reply 17):
System/360

Interesting to hear you guys discussing the S/360, my dad was one of the first IBM engineers in Australia trained to service the 360, indeed much of his advanced training was in the US which is how I and the rest of my family spent most of a year living in San Jose CA and Poughkeepsie NY.



If your camera sends text messages, that could explain why your photos are rubbish!
User currently offlinerwessel From United States of America, joined Jan 2007, 2238 posts, RR: 2
Reply 28, posted (1 year 7 months 1 week 2 days 23 hours ago) and read 6282 times:
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Quoting kl671 (Reply 25):
Car tire manufacturers apparently share your point of view. Tire widths are measured in millimeters while the diameter is in inches.

I am sure there is a good reason for this but I can't think of one!

Because the wheels the tires go on are measured in inches.   

Seriously, though, that's about it. It's an interface between two rather distinct parties, where the bit of commonality is valuable, and the benefits of a change are roughly non-existent.


User currently offlineScooter01 From Norway, joined Nov 2006, 1186 posts, RR: 8
Reply 29, posted (1 year 7 months 1 week 2 days 22 hours ago) and read 6244 times:
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Quoting rwessel (Reply 28):
Because the wheels the tires go on are measured in inches.

Actually, in the late 70's/early 80s, the US based Ford Motor Company introduced a metric size rim to be used on the 3rd generation Mustang 5.0 -I guess that means a 5 litre engine.

If I remember correctly, the only tire-manufacturer who produced a tire for it was Michelin with its 220/55R390TRX, where 390 was the rim diameter in mm, a little more than 15". As far as I know they used this wheelsize from the '82 through the '84 model-year -and how many of us remembers the TRX?

Quoting WrenchBender (Reply 20):
I wouldn't mind so much if the US actually used IMPERIAL instead of the bastardised US fluid system. A Gallon is 4.54 L not 3.78 L.

- coldn't agree more...

Scooter01

[Edited 2012-09-11 00:28:26]


"We all have a girl and her name is nostalgia" - Hemingway
User currently offlinevikkyvik From United States of America, joined Jul 2003, 9398 posts, RR: 27
Reply 30, posted (1 year 7 months 1 week 2 days 22 hours ago) and read 6238 times:
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Quoting bristolflyer (Reply 11):
The irony about the imperial system in the construction industry is that a 2" x 4" doesn't actually measure 2" x 4"

That one always makes me laugh. Or cry.

Quoting bristolflyer (Reply 11):
Anyone know what units show on airplane drawings?

Couldn't tell you (I would guess US units on US-produced airplanes). But for my company, which designs/manufactures products that go on space mission, our units are in inches.

Quoting StuckInCA (Reply 15):
I really think it's just a matter of what you're used to.

  

In college, I was used to metric. For problems in US units, I'd sometimes convert the input values to metric, do the calculations, then convert the result back to US. Was just easier to do all the calcs in metric.

Quoting StarAC17 (Reply 23):
The biggest value as an engineer to the metric system is based on values of 10 such as that 1km is 1000m, 1m is 1000mm, 1mm is 1um etc.* It increases productivity.

  



"Two and a Half Men" was filmed in front of a live ostrich.
User currently offlinestealthz From Australia, joined Feb 2005, 5609 posts, RR: 45
Reply 31, posted (1 year 7 months 1 week 2 days 21 hours ago) and read 6217 times:
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Quoting Scooter01 (Reply 29):
If I remember correctly, the only tire-manufacturer who produced a tire for it was Michelin with its 220/55R390TRX, where 390 was the rim diameter in mm, a little more than 15". As far as I know they used this wheelsize from the '82 through the '84 model-year -and how many of us remembers the TRX?

The Michelin TRX was another "radical" tyre design that required a different type of wheel so the best way to diffentiate was to again make it in odd sizes "(390mm I believe the only mass produced size) this prevented the tyres being mountaed on unsuitable rims.
Unlike the Dunlop Denovo, Michelin will still manufacture, to special order,TRX tyres for cars that were fitted with them as std equipment(hate to think what they cahrge for them!)



If your camera sends text messages, that could explain why your photos are rubbish!
User currently offlineKiwiRob From New Zealand, joined Jun 2005, 6641 posts, RR: 3
Reply 32, posted (1 year 7 months 1 week 2 days 18 hours ago) and read 6150 times:

Quoting Scooter01 (Reply 29):
and how many of us remembers the TRX?

I do, my granddad had a 1980's M635i which used metric tyres, Michellin still makes a batch every so often.

Here's what they make.

http://www.michelin-passion.com/pass...odeRubrique=44&lang=EN&dimension=1

[Edited 2012-09-11 03:42:03]

User currently offlineOA260 From Ireland, joined Nov 2006, 26497 posts, RR: 58
Reply 33, posted (1 year 7 months 1 week 2 days 18 hours ago) and read 6147 times:

Quoting bristolflyer (Thread starter):
Anyone have preferences, and why?

Having been brought up in England I learnt that way too but also being in Greece during my childhood I learnt both . I actually use both and it comes naturally to me to swap . Just like Miles and KM I can use both without issue and know how to convert without any issue. I dont really have a preference.



AEGEAN-OLYMPIC AIR - ΟΛΥΜΠΙΑΚΗ " μέλος στη Star Alliance
User currently offlineAesma From France, joined Nov 2009, 6110 posts, RR: 9
Reply 34, posted (1 year 7 months 1 week 2 days 16 hours ago) and read 6034 times:

Being in the computer industry imperial units are prevalent (well, inches, really) so I have an idea of what some sizes are, for example I'm using 24" screens right now. But I rarely do the conversion. Watching lots of US movies and TV series in English I also am used to feet and yards, roughly, and when a home is described as 2000 square feet it means 200m² (not really precise I know). I learned the nautical miles and knots as a kid since my father is a sailor.

The problem with the Imperial system is not the units values but that there is no logic in going from one size to the next. I'm very logical since childhood and knowing that 1Kg is the same thing as 10*10*10cm of water is something I found great and helped me a lot at school, since I couldn't be bothered to follow instructions and just solved problems my way.

Quoting fr8mech (Reply 10):
How do they build homes in Metric nations?

Using concrete blocks !



New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
User currently offlineDeltaMD90 From United States of America, joined Apr 2008, 7276 posts, RR: 52
Reply 35, posted (1 year 7 months 1 week 2 days 5 hours ago) and read 5922 times:

I prefer metric but at the end of the day, it's not really a big deal. If we were to change, I think they should start putting the speed limits and temperatures in both units, posted next to each other, and over the years, slowly switch over completely. Because even someone mathematical like me has no concept of C, kg or kms (without slowly converting in my head) which is really needed to be practical. I can go outside and say "it feels like 80F out here" but not really know what 15C would feel like, for example.

But the imperial system has the best unit of measurement, IMO, the foot. I personally find meters too big a lot of times, and cm are often too small. I like the foot



Ironically I have never flown a Delta MD-90 :)
User currently offlinelewis From Greece, joined Jul 1999, 3592 posts, RR: 5
Reply 36, posted (1 year 7 months 1 week 2 days 5 hours ago) and read 5912 times:

Quoting DeltaMD90 (Reply 35):
But the imperial system has the best unit of measurement, IMO, the foot. I personally find meters too big a lot of times, and cm are often too small. I like the foot

There is the decimetre (dm) but it is rarely used. People tend to use 0.x meters most of the time.


User currently offlineRevelation From United States of America, joined Feb 2005, 11929 posts, RR: 25
Reply 37, posted (1 year 7 months 1 week 2 days 5 hours ago) and read 5911 times:

Quoting stealthz (Reply 27):
Interesting to hear you guys discussing the S/360, my dad was one of the first IBM engineers in Australia trained to service the 360, indeed much of his advanced training was in the US which is how I and the rest of my family spent most of a year living in San Jose CA and Poughkeepsie NY.

I've been to Pok a few times for business back in my IBM days, although 'home base' was a half hour or so up the Hudson in Kingston. Pok was where a lot of the CPU design got done in those days, although some was being done in other places too. Also a lot of the mainframe software was done in Pok. SJ was mostly where IBM did storage products, DASD in IBM lingo.



Inspiration, move me brightly!
User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 38, posted (1 year 7 months 1 week 2 days 5 hours ago) and read 5912 times:

For a very good summary of the problem read Alexander Graham Bell's address to congress. It is more than a 100 years old today but it is just as valid, if not more.

If it is too much reading:
Few people have any adequate conception of the amount of unnecessary labor involved in the use of our present weights and measures


User currently offlineDeltaMD90 From United States of America, joined Apr 2008, 7276 posts, RR: 52
Reply 39, posted (1 year 7 months 1 week 2 days 5 hours ago) and read 5908 times:

Quoting lewis (Reply 36):
There is the decimetre (dm) but it is rarely used. People tend to use 0.x meters most of the time.

Yeah, I know of dm, just thought it wasn't really used. I guess 0.1 meters works. In the end though, barring math and science, people seem to operate fine transferring between imperial US and metric everywhere else. I do wish we'd switch though, I just don't see any compelling reason...



Ironically I have never flown a Delta MD-90 :)
User currently offlineKen777 From United States of America, joined Mar 2004, 8045 posts, RR: 8
Reply 40, posted (1 year 7 months 1 week 2 days 4 hours ago) and read 5897 times:

Quoting StarAC17 (Reply 23):
For 1 dimensional units it is no big deal and a speed limit is because it is a rate there is only the value between km and miles that needs to be considered.

That just brought to mind another cost increase when moving to metric: resale value of cars.

When we moved to PER in 76 we bought a Toyota Corona - actually a pretty nice car.

Traded it in after it hit 100,000 - which caused us to get less on the trade in. That was 100,000 K's, which is just over 62,000 miles. There is, unfortunately, a psychological factor in that 6 digits that you pay for.

Quoting StarAC17 (Reply 23):
Whereas 1 mile is 5280 ft, 1yd is 3ft, 1 ft is 12 inches. and there is no easy way to convert values.

Of course there is - just use your conversion app on your iPhone.  


User currently offlineokie From United States of America, joined Jul 2003, 2851 posts, RR: 3
Reply 41, posted (1 year 7 months 1 week 2 days 3 hours ago) and read 5888 times:

Quoting Scooter01 (Reply 29):
Actually, in the late 70's/early 80s, the US based Ford Motor Company introduced a metric size rim to be used on the 3rd generation Mustang 5.0 -I guess that means a 5 litre engine.

I had a friend at the time that had a Ford Thunderbird that had the metric rims.

Quoting stealthz (Reply 31):
Unlike the Dunlop Denovo, Michelin will still manufacture, to special order,TRX tyres for cars that were fitted with them as std equipment(hate to think what they cahrge for them!)

Even back then the friend found it cheaper to replace the rims along with the tires when then tires wore out. The bolt pattern stayed the same for the rims. So at least they left you and escape route.

Okie


User currently offlineRobertNL070 From Netherlands, joined Sep 2003, 4529 posts, RR: 10
Reply 42, posted (1 year 7 months 1 week 9 hours ago) and read 5734 times:

Living in mainland Europe of course I use the metric system: kilograms, kilometers (per hour), (milli)litres, degrees Celsius et cetera. However, also in Dutch my car has 17-inch alloy wheels, IIRC my pushbike has 28-inch wheels, my television has a 42-inch screen and I'm sitting behind my 15-inch Mac Book Pro. Screwed up, or what!


Youth is a gift of nature. Age is a work of art.
User currently offlineBongodog1964 From United Kingdom, joined Oct 2006, 3475 posts, RR: 3
Reply 43, posted (1 year 7 months 1 week 7 hours ago) and read 5693 times:

Quoting fr8mech (Reply 10):
Quoting bristolflyer (Thread starter):
2x4, 2x6 etc and multiples of 4' for sheet materials.

How do they build homes in Metric nations?

We build homes using 100 x 50 studs and we nail sheets of 2240 x 1220 x 12.5 plasterboard to them !!

Good thing we still have imperial on our tape measures as we still place the studs 16" apart which works exactly for a sheet. Metric measurements for them just don't work properly.

Quoting bristolflyer (Reply 11):
That's interesting. The irony about the imperial system in the construction industry is that a 2" x 4" doesn't actually measure 2" x 4" - so converting wouldn't be that much of a chore!

4" x 2" refers to the sawn dimension of the timber. If its purchased sawn it will be that size. If however it is sold planed it will be the same piece of timber passed through a planer which will reduce it by about 1/8" on each dimension
Of course here in the UK thats a 100 x 50 PAR which measures 97 x 47.


User currently offlinesteex From United States of America, joined Jun 2007, 1564 posts, RR: 9
Reply 44, posted (1 year 7 months 1 week 3 hours ago) and read 5646 times:

Quoting lewis (Reply 8):
"how many inches in a mile?"

In fairness, people wouldn't know this because it's skipping a "step" in between (the foot). It's very rare that you would have a measurement in miles and instead want to have it in inches (or vice versa). I realize the metric system eliminates that problem entirely, but that particular problem doesn't really exist within the standard units either.

Quoting StarAC17 (Reply 23):
The biggest value as an engineer to the metric system is based on values of 10 such as that 1km is 1000m, 1m is 1000mm, 1mm is 1um etc.* It increases productivity.

It all depends on what kind of engineering you do, I'm sure. In my field, all measurements for work in the USA are completed using decimals of feet rather than feet and inches. That makes it no easier or harder than the work I do using the metric system (I have no real preference and am comfortable with either).

Quoting Bongodog1964 (Reply 43):
4" x 2" refers to the sawn dimension of the timber. If its purchased sawn it will be that size. If however it is sold planed it will be the same piece of timber passed through a planer which will reduce it by about 1/8" on each dimension
Of course here in the UK thats a 100 x 50 PAR which measures 97 x 47.

In the USA, the 2" x 4" dimension is the undried, unplaned measurement. Drying and planing both reduce the size of the wood, and the end result is a piece of lumber that loses a full half inch from each dimension. The established standard for a 2x4 is 1.5" x 3.5" for construction.


User currently offlineokie From United States of America, joined Jul 2003, 2851 posts, RR: 3
Reply 45, posted (1 year 7 months 1 week 2 hours ago) and read 5633 times:

Quoting steex (Reply 44):
The established standard for a 2x4 is 1.5" x 3.5" for construction.

That standard was adopted in 1961. Previous it was 1 5/8" (1.625) x 3 5/8" (3.625)
Try replacing or adding a door casing to an older building.
Plan A: Make your own
Plan B: Place a special order and wait weeks to get it.
Plan C: Carve out the sheet-rock (wall board) an 1/8" for the trim.

Plan C usually wins

Okie


User currently offlinesccutler From United States of America, joined Jan 2000, 5393 posts, RR: 26
Reply 46, posted (1 year 7 months 1 week 1 hour ago) and read 5625 times:

Quoting okie (Reply 4):

I think Pres Carter started the shift near 40 yrs ago with a goal of being transitioned by 2000. (30yrs)
Now it has been close to 40 years.

Not so much... the metric conversion movement was already in trouble by 1976.

As a kid in elementary school (mid-sixties), I was taught the metric system from the start, with general statement that we'd be converting over around 1970. It was not controversial at that time, the teachers taught it, we learned it. This was in Dallas.

I really cannot grasp why the changeover to metric has ever been objected to; it simply makes better sense.

As a practical matter, though it is not so commonly known, most US manufacturing changed over to metric a while back.



...three miles from BRONS, clear for the ILS one five approach...
User currently offlineMadameConcorde From San Marino, joined Feb 2007, 10728 posts, RR: 38
Reply 47, posted (1 year 7 months 6 days 22 hours ago) and read 5603 times:

Those brilliant minds, the scientists, engineers and Space researchers in Russia and the U.S. who had sent the first satellite to Space, the first man to Space and the first man on the Moon did not use imperial measures. Neither those who created and built Concorde.

A genius such as Nikola Tesla did not use Imperial measure, not Marie Curie either.

That for me is a good enough reason to think the whole world should change to the metric system once and for all.

This was the one thing that shocked me when I first travelled across the Atlantic to the U.S. in 1969 to see all measures were imperial and the temperatures in Farenheit degrees rather than centigrades. I thought to myself how can a country so advanced as the U.S. still use the old measures rather than the metric system. Quarts of milk, miles per hour... It just made no sense.

   



There was a better way to fly it was called Concorde
User currently offlinedandaire From UK - Wales, joined Jul 2008, 65 posts, RR: 0
Reply 48, posted (1 year 7 months 6 days 16 hours ago) and read 5544 times:

Quoting B777LRF (Reply 6):
Aviation is another such example, with every single (western built) aircraft in existence is based on inches.

I don't know how you define "Western", maybe you mean American but there are an awful lot of aeroplanes made in France and Germany that are designed and built using the Metric system?

Quoting bristolflyer (Reply 11):
Anyone know what units show on airplane drawings?

At Airbus the drawings use the Metric system. I know when British Aerospace used to make the wings for the A300 aircraft, the drawings used the Imperial system while Aerospatiale in France built the fuselage using the Metric system and guess what, they fitted together ok.
  



Old age and treachery will triumph over youth and skill.
User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 49, posted (1 year 7 months 6 days 14 hours ago) and read 5517 times:

Like most people, I've had to work with either or both in my time.

On the one hand I think 'Imperial' works far better for larger measurements. In that field it's more 'natural.' An inch approximates to the top joint of your thumb, a foot is - well - a foot  , and a yard is a long pace. Since I was a Chartered Surveyor by profession, 'imperial' made it very easy to 'guess-timate' the area of a piece of land, etc.

And miles are arguably a much more 'sensible' distance for long trips than kilometers (especially the 'nautical mile,' the 'knot,' 2,000 yards, which is of course still used in aviation).

On the other hand, though, I'd be lost without millimetres for the small stuff nowadays. I got thoroughly fed up with messing about with things like 'sixty-fourths of an inch,' and even 'thous' (one thousandth of an inch) in my younger days.

I guess there's still room for both systems to co-exist, really....... 'horses for courses'........

[Edited 2012-09-14 07:45:22]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineronglimeng From Canada, joined Oct 2006, 624 posts, RR: 0
Reply 50, posted (1 year 7 months 6 days 14 hours ago) and read 5504 times:

I like to take units from both systems...

In carpentry work, a millimetre is as accurate as I can get, and a centimetre is a little more precise than an inch for the estimating that I do. Working with those friggin' fractions is eliminated.

For distances, I've accepted kilometres after some reluctance.

I still use pounds. Kilograms are to imprecise for me even though my weight appears on the scales as a smaller number.

For temperature, I still like Fahrenheit precision - useful in measuring the sensitive range near room temperatures. The difference between Celsius degrees is almost twice that of Fahrenheit and 0 degrees F has real meaning, 0 deg C is nothing to write home about.


User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 51, posted (1 year 7 months 6 days 14 hours ago) and read 5497 times:

Quoting NAV20 (Reply 49):
On the one hand I think 'Imperial' works far better for larger measurements. In that field it's more 'natural.' An inch approximates to the top joint of your thumb, a foot is - well - a foot  , and a yard is a long pace. Since I was a Chartered Surveyor by profession, 'imperial' made it very easy to 'guess-timate' the area of a piece of land, etc.

In Scandinavia a mile (mil) is 10 km, much better for long distances  

As to the natural distances. Go out and measure the length of peoples feet and you will be hard pressed to find one that is a foot long. Same with paces, you will be hard pressed to find one that is a yard.

I see three major problems with imperial. Which isn't imperial but different customary units. And this is the first problem, a foot isn't a foot. In US a foot represent two different distances. When foot was commonly used around the world it represented a myriad of different distances.

The second problem is that it is a lot more time consuming. It take more time to do all conversions between inch, foot, mile and when fractions are involved it too add a lot of time. It isn't difficult. Just time consuming.

The third is something that few will experience but I have spent a fair amount of time designing things and it is a royal pain to fit imperial style distances to drawings. They take so much more space.

I really do no care about if we use a meter, foot, yard or something else as the distance base unit but I very much want the decimal system applied after that. I also wish that US can finally take the step to join the rest of the world so we can skip the nonsense of multiple systems.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 52, posted (1 year 7 months 6 days 13 hours ago) and read 5483 times:

Agree entirely that Celsius is far too imprecise, too coarse, 'not enough degrees.' Ronglimeng.

Interested by your comments on 0 degrees Fahrenheit 'having real meaning,' though? My understanding is that Fahrenheit sought to place his 'zero temperature' at the freezing point of seawater (a laudable intention, given that mariners would have had more use for thermometers, and more problems with freezing water, than most people in those days); but that in the event he got it a bit wrong (too low)?

So what is its 'real meaning' nowadays?

PS - crossed with your post, cmf. Yes, agree that 'feet' and 'paces' were less than 'precise' - but I 'long-paced' out distances countless times in my professional days (especially when young and junior!) and when we went back later and measured it properly with a surveying chain, it was surprising how accurate the 'rough' figures turned out to be.

The British/Commonwealth surveying ('Gunter's') chain, of course, is an oddity in its own right - given that it's sixty-six feet long, and has a hundred links.........   But it's a damn sight lighter to carry around than the (100-foot) 'Engineer's' chain. And, of course, it fits in with the traditional British (and Commonwealth, and US) agricultural area measurement, the acre. One acre equals 4,840 square yards, 43,560 square feet.

If you want that in metric, an acre is 4,046.8564224 square metres, or 0.40468564224 of a hectare.   Given that most land sales in Britain are still based on acreage, as they have been since the Middle Ages, you can probably see why they've so far been reluctant fully to embrace the Metric System!  

[Edited 2012-09-14 09:32:28]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineKlaus From Germany, joined Jul 2001, 21353 posts, RR: 54
Reply 53, posted (1 year 7 months 6 days 13 hours ago) and read 5479 times:

Quoting NAV20 (Reply 49):
And miles are arguably a much more 'sensible' distance for long trips than kilometers (especially the 'nautical mile,' the 'knot,' 2,000 yards, which is of course still used in aviation).

Nautical miles are not part of the imperial system and have nothing to do with it. They are an angular metric (1 arc minute).

Kilometers are effectively the decimal version of that since 1km ~= 1/40000 equator circumference (historically).

All the other "miles" are completely arbitrary with no fundamental meaning whatsoever.

Quoting NAV20 (Reply 49):
I guess there's still room for both systems to co-exist, really....... 'horses for courses'........

There is zero sense in keeping the imperial system around. It is a completely pointless duplication of the metric system, just with a huge mess of inconsistencies even within itself and generating substantial added overhead.

The only reason why it still exists (effectively only in the USA) is sheer inertia, regardless of the cost and effort it keeps consuming.

Quoting NAV20 (Reply 52):
Agree entirely that Celsius is far too imprecise, too coarse, 'not enough degrees.'

What's the problem? That's what decimals are for.

[Edited 2012-09-14 08:56:34]

User currently offlineRara From Germany, joined Jan 2007, 2010 posts, RR: 2
Reply 54, posted (1 year 7 months 6 days 13 hours ago) and read 5475 times:

Quoting lewis (Reply 2):
I do prefer temperatures in F over C though. Even though C makes more sense in science (0 freezing point, 100 boiling point), the F scale is much wider and offers more accurate temperature readings for everyday use. In order to achieve that, we would have to use decimals in C when talking about the weather.

Really? I think the celsius degree is just at the limit of where a difference becomes noticeable. For all intends and purposes, there is no difference between 73 and 74 degree weather. Nobody is going to notice it, so why have the distinction? On the other hand, the difference between 20 and 21 degrees just might be ever so slightly noticeable, so it makes sense to start differentiating between it.

Of course, for scientific purposes and statistics, we need greater precision that one degree C, but for that we have the decimals.



Samson was a biblical tough guy, but his dad Samsonite was even more of a hard case.
User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 55, posted (1 year 7 months 6 days 12 hours ago) and read 5445 times:

Did a bit of research, and I find that the 'Gunter's chain' was invented by a guy named Edmund Gunter way back in 1620. AND, more important, he did indeed invent it precisely BECAUSE the acre didn't fit in with the, also newly-invented and 'infant,' decimal system:-

"The chain is divided into 100 links, marked off into groups of 10 by brass rings which simplify intermediate measurement. Each link is 7.92 inches long, with 10 links making slightly less than 6 feet 8 inches. The full length of the chain is 66 feet.

"Gunter's chain reconciled two seemingly incompatible systems: the traditional English land measurements, based on the number 4, and the newly introduced system of decimals based on the number 10. Since an acre measured 10 square chains in Gunter's system, the entire process of land measurement could be computed in decimalized chains and links, and then converted to acres by dividing the results by 10."


http://en.wikipedia.org/wiki/Gunter's_chain

Funny what you find when you look.......... But interesting, I hope?  



"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineAesma From France, joined Nov 2009, 6110 posts, RR: 9
Reply 56, posted (1 year 7 months 6 days 12 hours ago) and read 5437 times:

Quoting ronglimeng (Reply 50):
0 degrees F has real meaning, 0 deg C is nothing to write home about.

0 deg C is when you can expect ice on the roads and snowfall, I'd say it's pretty significant.



New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
User currently offlineronglimeng From Canada, joined Oct 2006, 624 posts, RR: 0
Reply 57, posted (1 year 7 months 6 days 10 hours ago) and read 5380 times:

Okay, but I'd very much prefer to walk to school on a windy morning when it's 0 deg C rather than 0 deg F !

[Edited 2012-09-14 11:59:36]

User currently offlinelewis From Greece, joined Jul 1999, 3592 posts, RR: 5
Reply 58, posted (1 year 7 months 6 days 7 hours ago) and read 5328 times:

Quoting Rara (Reply 54):

It does kind of make sense with thermostats (unless you have one that goes in .5C increments). I didn't get F when I moved to the US but I now see why it is a bit better, from a scale point of view. I have never heard someone in Europe, whether in everyday life or the weather forecast, using decimals for temperatures.

Quoting ronglimeng (Reply 50):
0 degrees F has real meaning, 0 deg C is nothing to write home about.

0 C is the freezing point of water (and 100C the boiling point). It does have real meaning in everyday life, as well as in science - hence why the Kelvin scale is exactly the same but shifted.


User currently offlineDNDTUF From France, joined Feb 2012, 27 posts, RR: 0
Reply 59, posted (1 year 7 months 6 days 6 hours ago) and read 5312 times:

Having been brought up in the UK, like most people my age, I seem to be stuck in the middle of the two systems! We must be the only country in the world where people buy petrolium in litres and drive their cars in miles - how many miles per litre does your car get? Who knows?  

We measure meat and vegetables in Kg but buy our milk and beer in pints. In my experience, the older generations still measure temperature in Farenheit but a lot of people, including my parents, measure hotter tempertures in Farenheit and colder temperatures in Celcius! I guess is has more of an effect saying it's 80F ouside and -10C than their equivalents.

I've lived in France for the past three years and have slowly forgotten imperial measurements. Although I have a good idea about the distance in length of a metre or kilometre, I have a hard time equating that into height. I still cannot seem to picture when someone tells me they are 1m70cm - I can't imagine how tall they are.

I really wish the UK government would take steps to make the country become fully metric.


User currently offlineDeltaMD90 From United States of America, joined Apr 2008, 7276 posts, RR: 52
Reply 60, posted (1 year 7 months 6 days 5 hours ago) and read 5306 times:

Quoting lewis (Reply 58):
Quoting ronglimeng (Reply 50):
0 degrees F has real meaning, 0 deg C is nothing to write home about.

0 C is the freezing point of water (and 100C the boiling point). It does have real meaning in everyday life, as well as in science - hence why the Kelvin scale is exactly the same but shifted.
Quoting Aesma (Reply 56):
Quoting ronglimeng (Reply 50):
0 degrees F has real meaning, 0 deg C is nothing to write home about.

0 deg C is when you can expect ice on the roads and snowfall, I'd say it's pretty significant.

I think he mean that "0 degrees" (C) isn't that cold but "0 degrees" (F) is. As in it doesn't really "mean much" to say 0 degrees in C because it's not too cold but F is. Yes 0 degrees for freezing is practical but over in America, you have exactly 0 people that take a minute to think "what is freezing again?" 32F is synonymous with freezing. Imperial is not as good as metric IMO but it doesn't really present any real challenges (except 5280 feet in a mile, that's just stupid)



Ironically I have never flown a Delta MD-90 :)
User currently offlineRara From Germany, joined Jan 2007, 2010 posts, RR: 2
Reply 61, posted (1 year 7 months 6 days 5 hours ago) and read 5300 times:

Quoting lewis (Reply 58):
It does kind of make sense with thermostats (unless you have one that goes in .5C increments).

That's true. I do have one that goes in .5C increments and you're right, in that case half a degree makes a difference, for which Fahrenheit would be sufficiently precise without decimals.



Samson was a biblical tough guy, but his dad Samsonite was even more of a hard case.
User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 62, posted (1 year 7 months 6 days ago) and read 5271 times:

Quoting DNDTUF (Reply 59):
Having been brought up in the UK, like most people my age, I seem to be stuck in the middle of the two systems! We must be the only country in the world where people buy petrolium in litres and drive their cars in miles - how many miles per litre does your car get? Who knows?

Australia is 'guilty as charged' as well, DNDTUF; though we have kilometres as well. I expect that most people, like me, have given up buying fuel by quantity and just habitually buy a 'money' amount. Come to think of it, that must be hard on the service station proprietors; if costs go up and prices have to rise, they'll tend just to get the same amount of money per customer visit, while selling less fuel, for quite a while.

Did a bit more 'reading around' about Fahrenheit, and it appears that he may well just have set 'zero' at a level well below any level that was likely to occur in his part of Europe; so as not to have to burden people with having to use minus signs! If so, that was probably very sensible. Remembering that in those days the decklogs of ships, for example, were kept on slates; and even the 'official' logs usually had to be written up by candlelight, with quill pens, at night on a rolling ship - no place to start messing around with pluses and minuses! Pity the French Navy; they had to, since France adopted the metric system in 1795.

Quoting lewis (Reply 58):
It does kind of make sense with thermostats (unless you have one that goes in .5C increments).
Quoting Rara (Reply 61):
That's true. I do have one that goes in .5C increments and you're right, in that case half a degree makes a difference, for which Fahrenheit would be sufficiently precise without decimals.

Dead right - I happen to have Centigrade (full degrees only) on my own heating system, and more often than not, later in the evening, I have to give it an extra degree. Then I have to remember to put it back on 'automatic' before I turn in, otherwise it stays on all night........

[Edited 2012-09-14 21:47:44]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlinevictrola From United States of America, joined Apr 2008, 460 posts, RR: 1
Reply 63, posted (1 year 7 months 6 days ago) and read 5262 times:

I'm all for metric. I'm sick and tired of having to translate our stupid English system into metric when I am working with my customers around the world. This is just a case of ignorant American arrogance that we continue to use a system of measurements that has been abandoned by the rest of the world. The rest of the world is metric. So we should get with the program. I have no patience with stupid ignorant Americans who are incapable of dealing with metric measurements.

User currently offlinedcann40 From United States of America, joined Sep 2012, 303 posts, RR: 0
Reply 64, posted (1 year 7 months 5 days 2 hours ago) and read 5161 times:

Quoting rwessel (Reply 14):
Only one of those (days per year) actually has anything to do with nature. The subdivisions of a day or circle are completely arbitrary (although a fair case can be made that the "natural" subdivisions of a circle should be 2*pi radians, or something related to that, although that would probably be less practical)..

It's funny you mention that. I've heard more than a few people attempt to argue that all of these measurements have a basis in nature.

Quoting rwessel (Reply 14):

And folks - the U.S. doesn't use Imperial Units, it uses Standard Units (or more formally, "U.S. Customary Units").

I've been reading this thread with great interest because the fact that the U.S. has remained on the standard units system does, in my opinion, make some of what the country tries to export less competitive. But I chuckled when I saw people saying that the U.S. uses Imperial Units. Where did that idea come from? I was going to post a correction but then I saw yours.

I'd suggest people interested in this read the history of weights and measures. The wikipedia page is particular good for this - http://en.wikipedia.org/wiki/United_States_customary_units


User currently offlinestealthz From Australia, joined Feb 2005, 5609 posts, RR: 45
Reply 65, posted (1 year 7 months 5 days 2 hours ago) and read 5155 times:
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Quoting NAV20 (Reply 49):
and a yard is a long pace.
Quoting cmf (Reply 51):
Same with paces, you will be hard pressed to find one that is a yard.

This actually works well in my business, I provide roadside assistance services to a wide range of customers from private motorists in std cars, travellers with large trailers, Small commercial operators and heavy line haul transport operators.
Towing standard vehicles is no problem as all contractors have equipment to do that, the line haul operators know the exact dimensions and weight of their vehicle. The middle two groups are the most difficult, many people with caravans(travel trailers) , horse floats etc and smalll commercial operators often have no idea of the dimensions and weight of their vehicles( they damn well should) so we get them to pace out the length and make the assumption their pace is shorter than a std metre. If someone says their trailer or truck is 7 mtr, we can be assured of sending the approp equip to tow it since it will almost certainly be shorter! (Height is another matter few know that nor can they estimate it accurately)

Note to all in Sydney(indeed much of Australia), if you get stuck in traffic behind 50 tonnes of broken down Semi trailer or a stranded tourist coach, it is a pretty fair assunption that I or one of my colleagues will be working phones pretty hard trying to marshall resources to get it moved... just be patient!!



If your camera sends text messages, that could explain why your photos are rubbish!
User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 66, posted (1 year 7 months 4 days 21 hours ago) and read 5132 times:

Quoting stealthz (Reply 65):
This actually works well in my business

Yes, stealthz; this thread seems to be 'dividing' itself between the people who have had to 'improvise' on occasion, and those who (apparently quite angrily) see the whole exercise as some sort of 'religious conflict':-

Quoting victrola (Reply 63):
I have no patience with stupid ignorant Americans who are incapable of dealing with metric measurements.

My own feeling is, as I've implied, that the 'imperial' system is much more open to said improvisation - not least because it has its origins in 'natural' thnigs. The very first known systems of measurement were, as far as I know, largely based on natural dimensions; even the very first recorded one, the cubit, apparently equates to the distance between a man's elbow and the tip of his longest finger. Later came the mile, the Roman mille, which, it is believed, was the distance covered by a squad of Roman soldiers marching 1,000 double paces. I've already covered the (probable) derivations of inches, feet, and yards.

One that I haven't mentioned yet is the 'furlong.' The derivation of that is pretty well established. Medieval ploughmen used a 'rod' (also known as a 'pole' or 'perch' - also used, as 'perche,' in France at the same time) to control their teams of oxen, and this was also used to lay out fields. The best length was found to be about 16 feet - long enough to handle the oxen, short enough to be manageable). It is believed that the rod was also used to standardise the length of a new field. They made the fields 40 rods long; leading to the term 'furrow long,' which became the furlong. From there, eight furlongs made the already-established 'mile,' and so on.

The Metric System appears to have had no equivalent links whatever to any such 'natural' origins. It's hard to avoid the conclusion that the main motivation of its French inventors was to make sure that it was 'different' from the system previously imposed on the known world (as they saw it) by the British, 'Perfidious Albion.' But their efforts produced a system of measurement that was undeniably less flexible than the imperial one. It was based on ten, which is divisible only by 2 and 5; whereas twelve is divisible by 2, 3, 4, and 6.

Sadly, there could have been a compromise. Most of us would probably agree that the one really good thing that the metric system produced was the millimetre; we probably all use it habitually for smaller measurements. As it happens, one imperial foot is 304.8mm.. Had the 'metric' guys contented themselves with dividing the foot by exactly three hundred, we could have had (only very slightly larger) millimetres, and not had to go on messing about with all those blasted 'one-sixteenths' and one 'sixty-fourths' and so on for ever and a day. While not having to introduce all those completely arbitrary (and still not very convenient or practical) metres, kilometres, and whatever.

[Edited 2012-09-16 01:28:12]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineKlaus From Germany, joined Jul 2001, 21353 posts, RR: 54
Reply 67, posted (1 year 7 months 4 days 14 hours ago) and read 5063 times:

Quoting NAV20 (Reply 66):
The Metric System appears to have had no equivalent links whatever to any such 'natural' origins. It's hard to avoid the conclusion that the main motivation of its French inventors was to make sure that it was 'different' from the system previously imposed on the known world (as they saw it) by the British, 'Perfidious Albion.'

And now again without the tin foil hat:

One meter was originally defined as one millionth of the sea level distance from the north pole to the equator, which is about as globally neutral and mathematically sensible as it gets.

By now the definition has been re-adjusted to a physically defined , more precise value, but its actual size has effectively remained the same.

Quoting NAV20 (Reply 66):
But their efforts produced a system of measurement that was undeniably less flexible than the imperial one. It was based on ten, which is divisible only by 2 and 5; whereas twelve is divisible by 2, 3, 4, and 6.

The entire SI system (to which the meter contributes the distance metric) is completely linear and numerically uses the decimal system throughout. In particular, there is only one single metric for all distances, from subatomic particles to the size of the universe, using decimal scaling throughout without ever having to convert between different metrics as in the various old-style metrics.

Computing of lengths is just ordinary math – no intermediate unit conversions necessary. It doesn't get any simpler.

Quoting NAV20 (Reply 66):
Sadly, there could have been a compromise. Most of us would probably agree that the one really good thing that the metric system produced was the millimetre; we probably all use it habitually for smaller measurements. As it happens, one imperial foot is 304.8mm.. Had the 'metric' guys contented themselves with dividing the foot by exactly three hundred, we could have had (only very slightly larger) millimetres, and not had to go on messing about with all those blasted 'one-sixteenths' and one 'sixty-fourths' and so on for ever and a day. While not having to introduce all those completely arbitrary (and still not very convenient or practical) metres, kilometres, and whatever.

Compatibility with the outdated system was never a goal – the metric system was designed to completely replace the old systems, and it has, with only one major island of the old system remaining in the USA and generationally receding use in late-coming metric countries.

Skewing the millimeter that way would have been incompatible with the global definition anyway, so that was never an option.

Inches, feet and (non-nautical) miles are redundant overhead which is being phased out even where it still exists. Without the completely botched metrication in the USA they would already be a thing of the past, but it's still a sinking ship.

That western aviation navigation has been standardized to that medieval metric after WWII was a huge mistake which will cause quite a bit of pain when (not if) the inevitable transition will have to be tackled there as well.


User currently offlineMD11Engineer From Germany, joined Oct 2003, 13797 posts, RR: 63
Reply 68, posted (1 year 7 months 4 days 13 hours ago) and read 5052 times:

Quoting Klaus (Reply 67):
That western aviation navigation has been standardized to that medieval metric after WWII was a huge mistake which will cause quite a bit of pain when (not if) the inevitable transition will have to be tackled there as well.

There is a reason behind it: Avoiding confusion over voice radio.

But if you have a figure tenthousand something, it can only be an altitude in feet.
Aviation uses metric units as well, e.g. runway visual range is given in meters.

Jan


User currently offlineDeltaMD90 From United States of America, joined Apr 2008, 7276 posts, RR: 52
Reply 69, posted (1 year 7 months 4 days 13 hours ago) and read 5049 times:

Quoting Klaus (Reply 67):
That western aviation navigation has been standardized to that medieval metric after WWII was a huge mistake which will cause quite a bit of pain when (not if) the inevitable transition will have to be tackled there as well.

Aviation is all messed up. We use knots/NM, statute miles/feet, and Celsius. In the US we use in-HG while in Europe it's in mb. I wish they'd just transition fully to metric... but again, probably more trouble that it's worth



Ironically I have never flown a Delta MD-90 :)
User currently offlineKlaus From Germany, joined Jul 2001, 21353 posts, RR: 54
Reply 70, posted (1 year 7 months 4 days 13 hours ago) and read 5041 times:

Quoting MD11Engineer (Reply 68):
There is a reason behind it: Avoiding confusion over voice radio.

But if you have a figure tenthousand something, it can only be an altitude in feet.
Aviation uses metric units as well, e.g. runway visual range is given in meters.

When metric altitude will be the prescribed norm with no alternative possibility, there won't be any confusion either. The way to go is likely to make a hard cut without any hybrid transitional operation.

You want to fly beyond date xxxx-xx-xx? You need metric instruments and training. Period.

Effectively the russian airspace system would be rolled out globally.

Quoting DeltaMD90 (Reply 69):
Aviation is all messed up. We use knots/NM, statute miles/feet, and Celsius. In the US we use in-HG while in Europe it's in mb. I wish they'd just transition fully to metric... but again, probably more trouble that it's worth

Given that all the confusion will be history forever once it's all consistent, I would say that even a considerable one-time effort would be justified. It will surely take quite a bit of resolve and planning to get there, but the imperial system has more than halfway gone the way of the dodo already, so the changeover is definitely coming – the question is only when exactly and how exactly.


User currently offlineAesma From France, joined Nov 2009, 6110 posts, RR: 9
Reply 71, posted (1 year 7 months 4 days 13 hours ago) and read 5033 times:

Quoting NAV20 (Reply 62):
no place to start messing around with pluses and minuses! Pity the French Navy; they had to, since France adopted the metric system in 1795.

Except that before the centigrade scale, the French weren't using Fahrenheit but the Réaumur scale, pretty similar to the centigrade one except it was 0 to 80 from freezing point to boiling point.

Quoting NAV20 (Reply 66):
The Metric System appears to have had no equivalent links whatever to any such 'natural' origins. It's hard to avoid the conclusion that the main motivation of its French inventors was to make sure that it was 'different' from the system previously imposed on the known world (as they saw it) by the British, 'Perfidious Albion.'

Nice story, however at the time there was no system imposed by anybody. It was a mess and every town had its own measures for everything.



New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
User currently offlineMD11Engineer From Germany, joined Oct 2003, 13797 posts, RR: 63
Reply 72, posted (1 year 7 months 4 days 11 hours ago) and read 5005 times:

Quoting Klaus (Reply 70):
Quoting MD11Engineer (Reply 68):
There is a reason behind it: Avoiding confusion over voice radio.

But if you have a figure tenthousand something, it can only be an altitude in feet.
Aviation uses metric units as well, e.g. runway visual range is given in meters.

When metric altitude will be the prescribed norm with no alternative possibility, there won't be any confusion either. The way to go is likely to make a hard cut without any hybrid transitional operation.

You want to fly beyond date xxxx-xx-xx? You need metric instruments and training. Period.

Effectively the russian airspace system would be rolled out globally.

You didn´t get it. A big figure in the 10.000 range can only be an altitude, even if the recipient did not understand the rest clearly. An airspeed would be something in the hundreds range.

Jan


User currently offlineAesma From France, joined Nov 2009, 6110 posts, RR: 9
Reply 73, posted (1 year 7 months 4 days 10 hours ago) and read 5000 times:

Can't a METAR have 10000 meters visibility ?


New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
User currently offlineKlaus From Germany, joined Jul 2001, 21353 posts, RR: 54
Reply 74, posted (1 year 7 months 4 days 10 hours ago) and read 4994 times:

Quoting MD11Engineer (Reply 72):
You didn´t get it. A big figure in the 10.000 range can only be an altitude, even if the recipient did not understand the rest clearly. An airspeed would be something in the hundreds range.

I do indeed not see your point. Flight levels in meters do not differ from feet by orders of magnitude, but only by a factor of about 3. That changes nothing about the relative magnitudes of common speeds and common altitudes.


User currently offlinelarshjort From Denmark, joined Dec 2007, 1351 posts, RR: 0
Reply 75, posted (1 year 7 months 4 days 10 hours ago) and read 4972 times:

Quoting cmf (Reply 51):
In Scandinavia a mile (mil) is 10 km, much better for long distances

A swedish 'mil' which is still used in Sweden is 10000 meters long, but a danish one is only 7532,48 meters long.

A danish inch (tomme) is 26,1545mm which is very similar to the imperial one which is 25,4mm. That one has caused me some trouble because you can still buy yardsticks with danish inches on it. And the swedish tum is 24,7mm long.

/Lars



139, 306, 319, 320, 321, 332, 34A, AN2, AT4, AT5, AT7, 733, 735, 73G, 738, 739, 146, AR1, BH2, CN1, CR2, DH1, DH3, DH4
User currently offlineAesma From France, joined Nov 2009, 6110 posts, RR: 9
Reply 76, posted (1 year 7 months 4 days 9 hours ago) and read 4965 times:

BTW, aren't gliders using metric ?


New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
User currently offlineB777LRF From Luxembourg, joined Nov 2008, 1208 posts, RR: 3
Reply 77, posted (1 year 7 months 4 days 9 hours ago) and read 4975 times:

Quoting Aesma (Reply 73):
Can't a METAR have 10000 meters visibility ?

Nope, max is 9999 which means "visibility more than 10 KM". Keep in mind what METARs are used for, namely to land and depart aircraft. Once the visibility goes above 10 KM it gets academic to the task at hand. Same with CAVOK, which means no significant clouds below 5000 ft and visibility more than 10 KM (someone correct me if those figures are wrong), which translates into "cloud base and visibility will not play a factor in deciding whether or not you can land/take-off".



From receips and radials over straight pipes to big fans - been there, done that, got the hearing defects to prove
User currently offlineLFutia From Netherlands, joined Dec 2002, 3305 posts, RR: 28
Reply 78, posted (1 year 7 months 4 days 5 hours ago) and read 4920 times:
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Living in the US, I am very much against the Imperial system. I personally use bits and pieces of the Metric scaIe. I purposely set my phone to use Celcius for temperature, time is also in 24H instead of 12H and also my computer weather program is in Celcius. As for my GPS when I drive I toggle between Metric and Imperial.

As for the decimal system, I know the US loves to use decimals to describe the numbers but I much prefer the european use of commas ($1,25 instead of $1.25) which I find much easier to read. However my friends just love to make fun of me for writing numbers the 'european way' instead of the american way.

Leo/ORD



Leo/ORD -- Groetjes uit de VS! -- Heeft u laatst nog met KLM gevlogen?
User currently offlineAesma From France, joined Nov 2009, 6110 posts, RR: 9
Reply 79, posted (1 year 7 months 4 days 2 hours ago) and read 4888 times:

What about dates in the month/day/year format ? Who came up with that ?


New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 80, posted (1 year 7 months 4 days 1 hour ago) and read 4876 times:

Quoting Aesma (Reply 71):
Nice story, however at the time there was no system imposed by anybody.

Don't know about mainland Europe, Aesma, but in Britain the majority of 'weights and measures' were stipulated by statute by about the year 1600 - during the reign of Queen Elizabeth I. They also applied, of course, to British colonies, especially the biggest one (now the United States).

A large number of 'dimensional traditions' arose about that time, and have continued to this day.   I've already mentioned the (1620) 'Gunter's Chain,' 22 yards - that is now 'immortalised,' as it is the stipulated length of a cricket pitch, worldwide.   The heights of racehorses are still measured in 'hands' - originally a 'hand's breadth,' now standardised at four inches. And, of course, the tracks that they race on are still measured in furlongs.

Ever since those days too, we've laid out the playing area of football pitches (for most codes, including American football, and certainly including soccer pitches in Europe) to be approximately 100 yards by 50. That's because the original rules more or less specified the area of one of my ('beloved'  ) acres - 4,840 square yards.

Joking a bit up to now, of course. But now I have to get a bit more serious:-


Quoting Klaus (Reply 74):
I do indeed not see your point. Flight levels in meters do not differ from feet by orders of magnitude, but only by a factor of about 3.

Klaus, there aren't many 'abouts' permitted in aviation, particularly the 'big stuff.' The difference between (three-foot) yards and metres is actually 1.0936133. So an aeroplane flying at say 10,000 metres would not actually be anywhere near 30,000 feet, it would be the best part of 1,000 feet higher. So either aeroplanes fitted with metric altimeters would have to fly at ridiculously-complicated 'metric' heights (no doubt 'drowning in decimals'  ), or those still using imperial would have to do the same sort of thing with feet.

If you give a moment's consideration to the complications (and colossal cost) of any such switch - in terms of re-design, conversion, crew re-training, chart conversion, etc.) I'm sure that you will conclude that there is not even the remotest possibility of converting aviation to metric. On grounds of cost alone, leave alone anything else.

Besides which, the current system appears to be working as well as it ever has, arguably better. "If it ain't broke, don't fix it!"  

PS - Aesma, crossed with your post. People realised variations in the height of the sun quite early on (like maybe the Ancient Egyptians) and began counting years. However, at first they didn't have the instruments to be completely accurate. Julius Caesar is generally credited with having organised the modern calendar about 40 BC, with some changes made later (in the 1550s) by Pope Gregory XIII).

http://www.enotes.com/history/q-and-.../when-was-calendar-invented-288757

Hope you're not planning to decimalise THAT?  

[Edited 2012-09-16 22:08:54]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineKlaus From Germany, joined Jul 2001, 21353 posts, RR: 54
Reply 81, posted (1 year 7 months 4 days ago) and read 4861 times:



Quoting NAV20 (Reply 80):
Klaus, there aren't many 'abouts' permitted in aviation, particularly the 'big stuff.' The difference between (three-foot) yards and metres is actually 1.0936133. So an aeroplane flying at say 10,000 metres would not actually be anywhere near 30,000 feet, it would be the best part of 1,000 feet higher. So either aeroplanes fitted with metric altimeters would have to fly at ridiculously-complicated 'metric' heights (no doubt 'drowning in decimals'  ), or those still using imperial would have to do the same sort of thing with feet.

I'm well aware of the precise relationship; I was just countering Jan's argument that metrication would suddenly shift the values by multiple orders of magnitude, which it doesn't. It's actually just about(!) half an order of magnitude, which is unproblematic regarding Jan's argument of altitudes and speeds being sufficiently distinct to avoid miscommunications.

And no, parallel use would be a pretty horrible idea. I'm pretty sure they'll use a hard cut when the time comes.

Quoting NAV20 (Reply 80):
If you give a moment's considerations to the complications (and colossal cost) of any such switch - in terms of re-design, conversion, crew re-training, chart conversion, etc.) I'm sure that you will conclude that there is not even the remotest possibility of converting aviation to metric. On grounds of cost alone, leave alone anything else.

The imperial system is going away. It's actually mostly gone already. In most countries it is already an arcane, alien system which is to be specially learned only by pilots and a shrinking number of specialists in addition to the simple, linear one everyone is already using everywhere else. When the USA will finally give up on it as well, it will be completely obsolete. Ask any european on the street today what the size of an inch actually is, and very few will be able to tell you, and that number will only go further down. Even the few who can may actually disagree about the size due to the various local variations.

So there isn't even a decision involved in the if – only in the when and how. Given that particularly in commercial and military aviation we're dealing with well-controlled systems and procedures and since instruments are mostly digital even now already, it is absolutely doable.

Inconvenient? Sure. It will temporarily require quite a bit of effort and extra attention, lots of preparations, training, system updates, thorough validations and very careful ramping up of the new operations.

But this is just once and only temporarily, with unending benefits thereafter (the abolition of the inconsistency with russian airspace would be just one of them).

Quoting NAV20 (Reply 80):
Besides which, the current system appears to be working as well as it ever has, arguably better. "If it ain't broke, don't fix it!"

It's already broken today and needs to be kept together with ever-increasing amounts of tape and glue. Yes, the supply of tape and glue won't end tomorrow, but its time is still running out.

Even the most resilient anachronisms at some point are abolished when they become sufficiently cumbersome.

We're probably talking about a matter of a few decades down the road, but not about whether the imperial system will survive outside of history books. It's already beyond the point of no return.

The effort wasted on its artificial preservation has better uses even today.

[Edited 2012-09-16 22:16:37]

User currently offlineMD11Engineer From Germany, joined Oct 2003, 13797 posts, RR: 63
Reply 82, posted (1 year 7 months 3 days 21 hours ago) and read 4830 times:

I´m used to work with both systems (American aircraft are built to the US system). As long as you don´t have to convert from one system to another or calculate within the illogical imperial (or US) system it is ok (I see a nut and I know immediately if it is a 1/2" or 5/8" spanner I need, similarly as I know if I need a 10 mm or a 13 mm spanner for metric stuff).
Using a vernier or a micrometer screw in inches though is a pain in the neck. I use metric ones if necessary and concert.
To counter NAV20´s argument, if you are used to the metric system it is just as intuitive as the imperial one. I can pace out a piece of land and I know approximately the distance in meters. Similarly a centimetre is appr. the width of my little finger.
I find some uses of the imperial system very unlogic and confusing. like using pounds as both a unit of mass and of force.

Jan


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 83, posted (1 year 7 months 3 days 21 hours ago) and read 4825 times:

Quoting Klaus (Reply 81):
It's already broken today and needs to be kept together with ever-increasing amounts of tape and glue.

Interested to hear which areas of aviation you consider to be in that sort of fix, which could be remedied by metrication, Klaus?



"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineBongodog1964 From United Kingdom, joined Oct 2006, 3475 posts, RR: 3
Reply 84, posted (1 year 7 months 3 days 19 hours ago) and read 4790 times:

I can't see the USA ever going metric. if they were going to do so the time would have been shortly after the UK switched in the 1970's at which point the vast majority of the Worlds industries would have been on the same system.
We now have the technology to instantly convert from metric to imperial, so whats the problem ?

Here in the UK metrification has hit the buffers, we still have road signs in miles, we drink pints, we refer to our height and weight in feet and inches and stones and pounds. . There is simply not the political will to phase out the remainder of the imperial measurements in use.

Everything in my line of business is still in feet and inches. Though I was educated in metric, my father always used imperial so I'm fully conversant with both systems.


User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 85, posted (1 year 7 months 3 days 15 hours ago) and read 4750 times:

Quoting stealthz (Reply 65):
This actually works well in my business

It works because you don't need precision.

When I started playing golf I paced out distances in meters. Now I do it in yards. It works because I get close enough. Just as you get close enough.

Quoting NAV20 (Reply 66):
The Metric System appears to have had no equivalent links whatever to any such 'natural' origins.

What is the importance of natural origin? Especially since the natural isn't working well. Just look at the many different lengths inches, foot have/does represent.

Quoting NAV20 (Reply 66):
Had the 'metric' guys contented themselves with dividing the foot by exactly three hundred

Which foot?

Quoting MD11Engineer (Reply 72):
A big figure in the 10.000 range can only be an altitude

But flight levels are usually divided by 100.

Quoting larshjort (Reply 75):
A swedish 'mil' which is still used in Sweden is 10000 meters long, but a danish one is only 7532,48 meters long.

I know mil isn't often used in Denmark but I had understood it had been defined as 10 km just as in Norway and Sweden even though it came from a much shorter distance. In Sweden a mil was about 10,690m and in Norway about 11,300m. The difference between Sweden and Norway was due to different definitions of foot. Earlier than that it was anything from about 6km to almost 15km in just Sweden.

All in all it is just a good example of why it was time to standardize.

Quoting NAV20 (Reply 80):
If you give a moment's consideration to the complications (and colossal cost) of any such switch - in terms of re-design, conversion, crew re-training, chart conversion, etc.) I'm sure that you will conclude that there is not even the remotest possibility of converting aviation to metric. On grounds of cost alone, leave alone anything else.

Think of the conversion as a one time cost. Instead of paying for it every day in making conversions. China and a few other countries use metric. Russia changed to flight levels in ft only about a year ago. Obviously there is a need to standardize. Question is why to standardize on something that is different from most prevalent standard in other areas?

Quoting Bongodog1964 (Reply 84):
We now have the technology to instantly convert from metric to imperial, so whats the problem ?

Effort and errors.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 86, posted (1 year 7 months 3 days 14 hours ago) and read 4730 times:

Occurred to me that 'separation' would probably be 'a whole new ball game' if metric was introduced. At present it's 1,000 feet low down, and I believe 2,000 higher up (so all pilots and controllers have to say is 'flight level 15' and so on). I thought that the comparable separation figures in metres (as close as they could get, anyway) would probably be 300 metres lower down, 600 metres higher up. And I also thought that that would very probably throw up some pretty complicated numbers - some odd, some even; much more complicated than 5s, 10s, and 15s , with a much greater risk of error.

Tried researching it, and the first thing I hit on was an A.net thread in which the redoubtable Pihero provided an outline (apparently he used to fly to Russia). Turned out that my guess about 300 metres (600 in each direction, eastbound or westbound) was right; though at higher altitudes it was 500 (effectively 1,000 in each direction). Quote from Pihero below showing how complicated it can get:-

"For these countries,a standard altimeter setting calls for a flight level ("fright reverr " in Japanese) : you just say "xxx,maintaining flight level 11 thousand 600 meters".

"Over Russia, it is not easy to remember odd / even levels : there is a 300 m separation between eastbounds and westbounds until 8100 mat which point the separation becomes 500 m, like this ( is e/b )
13100>
12100
11100;
;
;
;
9100
8100
7500 etc..."


Countries Using Metric Altitudes For ATC (by Viscount724 Dec 14 2006 in Tech Ops)

As far as I'm concerned, no thank you guys, I'll pass......  

[Edited 2012-09-17 08:26:49]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineViscount724 From Switzerland, joined Oct 2006, 24075 posts, RR: 22
Reply 87, posted (1 year 7 months 3 days 5 hours ago) and read 4654 times:

Quoting Ken777 (Reply 21):
You do realize that if the US was to move to the UK Gallon all of our cars would get immediate improvements in milage. My old Caddy might hit 30 MPG on the interstates.

Before Canada switched from the Imperial to the Metric system during the 1970s, American tourists often wondered why their cars started getting better mileage when they visited Canada (since the Imperial gallon is about 20% bigger).

I think Canada switched from miles to kilometers on road signs in 1977/78. I had a 1977 Pontiac (built in Canada) with an odometer that read in miles. If memory correct the 1978 models switched to km, as did the primary scale on the speedometer.


User currently offlinesteex From United States of America, joined Jun 2007, 1564 posts, RR: 9
Reply 88, posted (1 year 7 months 3 days 3 hours ago) and read 4644 times:

Quoting cmf (Reply 85):
Question is why to standardize on something that is different from most prevalent standard in other areas?

I would imagine a significant reason would be that separation standards are set to a round number of feet, a direct conversion of which would make for strange requirements in metric. To reach a round metric number, they would need to either justify a reduction in separation or choose to enlarge the separation standards, which automatically forfeits capacity in constrained airspace.


User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 89, posted (1 year 7 months 3 days 2 hours ago) and read 4634 times:

Quoting steex (Reply 88):
I would imagine a significant reason would be that separation standards are set to a round number of feet, a direct conversion of which would make for strange requirements in metric. To reach a round metric number, they would need to either justify a reduction in separation or choose to enlarge the separation standards, which automatically forfeits capacity in constrained airspace.

That is a very poor reason. It would take next to no time for the new levels to become second nature. Aviation require memorization of much trickier information, used far less often,


User currently offlineQuokkas From , joined Dec 1969, posts, RR:
Reply 90, posted (1 year 7 months 3 days ago) and read 4622 times:

Quoting NAV20 (Reply 66):
It's hard to avoid the conclusion that the main motivation of its French inventors was to make sure that it was 'different' from the system previously imposed on the known world (as they saw it) by the British, 'Perfidious Albion.

As your own posts indicate, the mile was adopted from the Romans and was not uniquely British. Over time different miles came into being with a mile in France, Germany and Russia all being different lengths (and much longer than the miles in the United Kingdom where English, Scottish and Irish miles all differed in length.)

Suggestions to adopt a decimal system for coinage, weights and measures had been made long before France adopted the metric system. As early as 1586 Flemish mathematician and military engineer Simon Stevin had argued the importance of standardising units. In his "An Essay towards a Real Character and a Philosophical Language ", published in 1688, English philosopher John Wilkins had also argued for a decimal system.

Far from seeking to flick two fingers in the face of Perfidious Albion, the French were more concerned with the lack of standardisation within France and in neighbouring countries. Rather than adjust the existing units they decided to adopt a new system of units. That system has proven to be very useful. Funnily enough, in 1790 Thomas Jefferson proposed to Congress that the US adopt a decimal system using the traditional names for units. The proposal was considered but not adopted.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 91, posted (1 year 7 months 3 days ago) and read 4623 times:

Quoting cmf (Reply 89):
That is a very poor reason. It would take next to no time for the new levels to become second nature.

cmf, this is the aspect of the debate that, for the life of me, I cannot understand. The objective of making changes in ANY field is (or should be) that they are a positive step; that they improve on the current situation.

Thousands of feet have worked very well for the best part of a century. And, following your point, I'm sure that they are already 'second nature' not just to pilots from the USA and the Commonwealth (probably the majority, given the USA's leading position in world aviation) but also to pilots from 'metric' countries.

In this case you and others are suggesting that the industry changes from a system that basically involves just two numbers to one that would necessitate three. And please note that revealing point made by Pihero (a Frenchman brought up with the metric system):-

"...it is not easy to remember odd / even levels...."

I agree with you that pilots would adapt pretty readily to working in hundreds of metres; but switching to the metric system would clearly involve all pilots working with (and having to remember and adjust to) three figures instead of two. That would undeniably be a more complicated situation than the present one; and, in any sort of crisis, it would be (at least fractionally) more likely to lead to confusion and mistakes.

So would you (and other proponents of switching to metric) please give a straight answer to a very simple question:-

"What would be the advantages of switching to the metric system, which would justify the change to a three-figure system that would undeniably be more complex than the present one?"

[Edited 2012-09-17 22:09:24]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineMD11Engineer From Germany, joined Oct 2003, 13797 posts, RR: 63
Reply 92, posted (1 year 7 months 3 days ago) and read 4619 times:

Here is a list from 1848 stating the different definitions for a foot in different European countries:
http://upload.wikimedia.org/wikipedia/commons/c/cd/Fu%C3%9Fma%C3%9Fe1.jpg

(from Wikipedia)

Up to the introduction of the meter each of the more than 60 German principalities (some of them were not larger than a town) had it´s own measuring units. Often samples were attached to the town halls next to the market place:
, also from Wikipedia.
This is a historical example from Regensburg, Bavaria showing a "Schuh" (foot) and some other obsole units like "Elle" (originally the distance between the elbow and the tip of the middle finger of an adult man) and "Klatter"(an obsolete unit of which I couldn´t find a definition, it could have been the local equivalent of a "Spanne", the distance between the outstretched tips of thumb and index finger).

Jan


User currently offlineKlaus From Germany, joined Jul 2001, 21353 posts, RR: 54
Reply 93, posted (1 year 7 months 2 days 21 hours ago) and read 4593 times:

Quoting NAV20 (Reply 86):
As far as I'm concerned, no thank you guys, I'll pass......

Are you even affected? I know I'm not.

The transition will probably be a matter of a few months of noticeably increased effort for all involved (with a few years of background preparation), but when it's done it's easier for most involved (if not for all, depending on the ground-level metrication progress particularly in the USA).
 
Quoting NAV20 (Reply 91):
In this case you and others are suggesting that the industry changes from a system that basically involves just two numbers to one that would necessitate three.

10000m = 32808ft, so up to there there would usually be one digit less with metric altitudes; The last of the customary three-digit flight level digits would just be used more often if the same scheme was kept in use, but the first digit would often be zero or redundant.

This will become Increasingly irrelevant anyway, since voice radio will progressively be supplanted by direct data connections for essential airspace management, particularly with reduced separation.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 94, posted (1 year 7 months 2 days 16 hours ago) and read 4561 times:

Quoting Klaus (Reply 93):
Are you even affected?

Not yet. But if I find myself on a 'metric' flight and the pilots get confused and get the 'separation' wrong, I sure as hell could be.......

Quoting Klaus (Reply 93):
10000m = 32808ft, so up to there there would usually be one digit less with metric altitudes

No, Klaus - given that the flight levels in imperial are at intervals of 1,000 feet, pilots and controllers only have to quote the first two digits. If metric is introduced, entailing hundreds of metres rather than thousands, it would be necessary to quote three digits. That's shown by the Pihero quote above. The height concerned is 38,000 feet. That would be 'flight level three-eight' under present practice - but apparently, as he states, 'flight level 11 thousand 600 meters' in metric terms.

Quoting Klaus (Reply 93):
when it's done it's easier for most involved

In what way would anything be 'easier'? On the face of it, things would just be more complicated? I keep asking - what advantages would switching to metric produce?



"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineKlaus From Germany, joined Jul 2001, 21353 posts, RR: 54
Reply 95, posted (1 year 7 months 2 days 16 hours ago) and read 4559 times:

Quoting NAV20 (Reply 94):
Not yet. But if I find myself on a 'metric' flight and the pilots get confused and get the 'separation' wrong, I sure as hell could be.......

There will be no more confusion than there is today when there's a well-prepared changeover without confusing mixtures.

Quoting NAV20 (Reply 94):
No, Klaus - given that the flight levels in imperial are at intervals of 1,000 feet, pilots and controllers only have to quote the first two digits. If metric is introduced, entailing hundreds of metres rather than thousands, it would be necessary to quote three digits. That's shown by the Pihero quote above. The height concerned is 38,000 feet. That would be 'flight level three-eight' under present practice - but apparently, as he states, 'flight level 11 thousand 600 meters' in metric terms.

Not to my knowledge.

The altitude above is currently quoted as FL380 and it would be FL116 if it was just translated.

And an altitude of now 30000ft would be 9144m, so instead of FL300 it would be FL091 or FL91.

The extra long version you've quoted was necessary only because a special distinction needed to be made to separate the number from the customary levels in feet. That need for distinction vanishes when flight levels in feet are eliminated and the proper shorthand can be used again, just on a metric basis. And in many cases with one digit less.

With direct data communication between ground flight control and onboard FMS, aural radio will recede as a source for critical miscommunication about flight management anyway.

Quoting NAV20 (Reply 94):
In what way would anything be 'easier'? On the face of it, things would just be more complicated? I keep asking - what advantages would switching to metric produce?

Imperial measures are yet another "foreign language" for most aviators worldwide, since they don't use them anywhere else in life. Yes, it can be learned, but it is an island with a different metric from all of science (which is metric), from space exploration (dito – see a well-known mishap based on mixing imperial into it!) and from everything else in the rest of world with the sole exception of the USA.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 96, posted (1 year 7 months 2 days 15 hours ago) and read 4554 times:

Quoting Klaus (Reply 95):
Imperial measures are yet another "foreign language" for most aviators worldwide, since they don't use them anywhere else in life.

But surely, Klaus, if all the auto systems failed, and you had to fly an aeroplane manually, it would be a damn sight easier to keep close to 30,000 feet instead of 9,100 metres or whatever? Please answer my earlier question; what positive benefits, what improvements, in operational terms, would result from 'metricating' aviation?

I think the basic problem is that the five French mathematicians who originally devised the metric system 'started at the wrong end.' The British (strictly speaking, the English) started with the foot and worked up; the French started with the metre and worked down.

I was impressed by MD11's Post 92 above; which shows that, as late as 1848, 20 out of 28 countries were using the 'foot' or 'fuss' - and that the respective measurements were very close indeed. If those French mathematicians had taken note of that, started from there, and based the metre on a standardised 'foot,' we wouldn't be having this argument.

I'd love to get a group of people from all over the world together, hand sticks of various sizes to them, and ask them to estimate their lengths. Bet you that the ones who were brought up on feet and inches would get a lot closer to the correct lengths than those brought up with nothing to work with but centimetres?

The metre is just too plain big and cumbersome to be the basic measure. The fact that aviation still works (quite well and happily) on the foot, and any switch to metres would increase, not decrease, the complications just, to my mind, proves the point that the metre was a 'wrong turning' from the very beginning.

[Edited 2012-09-18 07:15:04]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 97, posted (1 year 7 months 2 days 2 hours ago) and read 4452 times:

Quoting NAV20 (Reply 91):
In this case you and others are suggesting that the industry changes from a system that basically involves just two numbers to one that would necessitate three.

Basically involves just two numbers? Guess you do not fly pressurized. But even if it took three digits, so what?

Quoting NAV20 (Reply 96):
Please answer my earlier question; what positive benefits, what improvements, in operational terms, would result from 'metricating' aviation?

Standardization. No need to learn aviation measurements. No mistakes because of conversions.


User currently offlineAesma From France, joined Nov 2009, 6110 posts, RR: 9
Reply 98, posted (1 year 7 months 1 day 5 hours ago) and read 4361 times:

I'm not a pilot yet, but I can see an advantage in the fact that altitudes and distances would use the same unit. For example if you end up gliding in an usually powered airplane, best glide of 9 means for each 1000m of altitude you will cover 9000m.


New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 99, posted (1 year 7 months 1 day 1 hour ago) and read 4336 times:

Quoting cmf (Reply 97):
Standardization. No need to learn aviation measurements. No mistakes because of conversions.

Thanks for the answer, cmf.  

Not sure about those 'advantages,' though. On 'standardisation,' as it happens, Russia and the CIS effectively switched back to 'imperial' last year - or rather they introduced a 'dual' system which gave priority to thousands of feet rather than metres. Here's an excerpt from the list of flight levels they're using now (please note the much more complex metric numbers):-

Track 180 to 359°
FL METERS FEET
20 600 2000
40 1200 4000
60 1850 6000
80 2450 8000
100 3050 10000


http://en.wikipedia.org/wiki/Flight_level

So, as far as I know, the only countries still giving priority to the metre are China, Mongolia, and some of the 'stans. Much simpler, surely, if they 'standardised' with the rest of the world, rather than all of us 'standardising' with them?

About 'aviation measurements,' surely at present, given that altitudes are counted in thousands of feet, the only numbers anyone has to learn are 10 to about 40? So, if you like, altitudes are already entirely 'metricated'?  

Don't understand your point about 'conversions'? If you mean the high-altitude switch from barometric pressure altitude to 'flight levels,' surely that would still be needed even if we switched to metric?

Aesma, thanks for your reply too. Given that the 'aviation mile' is already the nautical mile, the knot, 6,000 feet, that too is already 'metricated,' and therefore also permits 'matching' calculations (feet to feet) for sinkrate/achievable distance?

Seems to me that my earlier point is at the root of the problem were the metric system to be introduced. The metre is just too darned BIG to be anywhere near as useful/flexible as feet?

[Edited 2012-09-19 20:52:44]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineDeltaMD90 From United States of America, joined Apr 2008, 7276 posts, RR: 52
Reply 100, posted (1 year 7 months 1 day 1 hour ago) and read 4328 times:

I really don't see the problem with flight levels... I can see a problem with reporting/looking for traffic (traffic 3 miles for example, metric-folk would have to convert.) But who really has any concept of 33000 feet or 10000 meters? Especially since the altimeter displays in feet, you could just pretend the altimeter is in meters and the flight levels are in meters... flight levels and altitudes are more of numbers rather than actual distances pilots have to consciously think out


Ironically I have never flown a Delta MD-90 :)
User currently offlinePellegrine From United States of America, joined Mar 2007, 2216 posts, RR: 8
Reply 101, posted (1 year 7 months 1 day ago) and read 4314 times:

I use both, it depends on the situation. Both are convenient...due to what we're taught (edit: as an educated, worldly American).


oh boy!!!
User currently offlineAesma From France, joined Nov 2009, 6110 posts, RR: 9
Reply 102, posted (1 year 7 months 23 hours ago) and read 4331 times:

Quoting DeltaMD90 (Reply 100):
I really don't see the problem with flight levels... I can see a problem with reporting/looking for traffic (traffic 3 miles for example, metric-folk would have to convert.) But who really has any concept of 33000 feet or 10000 meters? Especially since the altimeter displays in feet, you could just pretend the altimeter is in meters and the flight levels are in meters... flight levels and altitudes are more of numbers rather than actual distances pilots have to consciously think out

Exactly, at flight level altitudes it doesn't matter much (well maybe over mountains, I know the altitudes of high mountains, in metres not feet).

My example of a gliding down aircraft involves lower altitudes and a need for an idea of distances to get to a landing spot.



New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 103, posted (1 year 7 months 18 hours ago) and read 4316 times:

Quoting NAV20 (Reply 99):
Russia and the CIS effectively switched back to 'imperial' last yea

They changed to what aviation use in most other places, i.e. standardization.

But it meant they broke with what is standard almost everywhere else.

Quoting NAV20 (Reply 99):
Don't understand your point about 'conversions'?

Every time you go from one system to another there is a conversion. With every conversion there are possibilities of mistakes.

If flight levels do not live in isolation. If they did we could just as well give even flight levels female names and odd levels male names and everything would be just as well.

But reality is they exist in an environment where there are many related measurements. If you use ft for flight levels then you should use ft for all heights. But heights are measured in m just about everywhere else so whenever there is interaction there is conversion, and ever so often, conversion errors.

Quoting NAV20 (Reply 99):
Seems to me that my earlier point is at the root of the problem were the metric system to be introduced. The metre is just too darned BIG to be anywhere near as useful/flexible as feet?

You keep saying so but I have never felt it and I can't remember anyone other place where I have heard it. you have also stated you prefer mm over inch. Well the metric system has cm which is to ft very close to what mm is to in. Then dm gives you another option.

When I grew up with used both of them very often whereas mm was reserved for very small distances. Today I hardly ever see dm used and mm or m are often used where it used to be cm. I can only conclude those intermediate measurements are not as important when you look at it with fresh eyes.

Keep in mind that this isn't about the metric system being superior in every regard. It is about the advantages of standardization. If imperial had been standardized instead of the many customary units then metric would never have happened. Russia changing to ft is an example of how important standardization is. Not a sign that ft is superior.


User currently offlineAesma From France, joined Nov 2009, 6110 posts, RR: 9
Reply 104, posted (1 year 7 months 11 hours ago) and read 4260 times:

It's true that dm is rarely used (even if the ubiquitous rulers at school are "double décimètres" aka 2dm). And mm is common in everything technical, even when talking about the length of a car : 4570mm. But I'd say one of the reason it is so is because conversion is so easy, so when you see 4570mm you instantly know it's 457cm or 4,57m and whatever "base unit" you're most comfortable with doesn't matter at all.


New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 105, posted (1 year 7 months ago) and read 4193 times:

Quoting cmf (Reply 103):
Today I hardly ever see dm used and mm or m are often used where it used to be cm.
Quoting Aesma (Reply 104):
It's true that dm is rarely used (even if the ubiquitous rulers at school are "double décimètres" aka 2dm).

Interesting, you guys. I fear that it rather reinforces my point that those French mathematicians in the 1790s should maybe have kept the 'foot'?  

According to this, the French did indeed use the 'foot' (the 'pied') prior to their intervention. Apparently it was introduced by Charlemagne in 790 AD. They also had the 'inch' ('pouse'), and a thing called the 'toise', which corresponded to the 'fathom,' which amounted to six English feet:-

http://en.wikipedia.org/wiki/Units_o...rance_before_the_French_Revolution

The fathom is especially interesting to me since it is still in use today by sailors (worldwide, as far as I know). Again, it started from a 'natural' dimension - the distance between a normal-sized man's fingertips when standing with his arms outstretched (check it out if you like, that STILL works!). Initially it's main use was for 'soundings' - throwing a weighted line, with knots marking every fathom, into the water to make sure that the ship or boat wasn't about to run aground.

But it also 'gave birth' to the knot, the nautical mile, which I've previously mentioned. Seamen in the old days initially had no way of estimating their speed; until the 'logline' was invented. The logline was (very possibly still is) a longish length of cord with knots tied into it at intervals of 8 fathoms, 48 feet; and with a board or baffle (perhaps ]really a 'log'' at first!  Smile) on the end. The old-time sailors found that by throwing it over, letting the cord run through their fingers for thirty seconds, and counting the 'knots,' they could get a pretty good estimate of their speed through the water - in 'nautical miles per hour.' Now better known as 'knots,' and still used pretty well universally as a measure of speed both at sea and in the air.

STILL difficult to understand how those guys in Paris could possibly have ignored all the (pretty practical) systems of measurement which were already in use in the 1790s, and come up with the (completely 'artificial') metre instead.

[Edited 2012-09-20 22:41:28]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 106, posted (1 year 7 months ago) and read 4179 times:

Quoting NAV20 (Reply 105):
Interesting, you guys. I fear that it rather reinforces my point that those French mathematicians in the 1790s should maybe have kept the 'foot'?

Which one? It took almost 200 years before the foot distance was finally standardized and even so it represents two different distances in USA,

Quoting NAV20 (Reply 105):
STILL difficult to understand how those guys in Paris could possibly have ignored all the (pretty practical) systems of measurement which were already in use in the 1790s, and come up with the (completely 'artificial') metre instead.

No it is very easy to understand. It was a requirement for the standardization to have a chance. France did not have a unified system but the French foot you referenced was some 10% longer than the current standardized international foot. Interestingly the international foot is not defined based on any of the natural measurements you reference but on the.... meter  Wow!


User currently offlineAesma From France, joined Nov 2009, 6110 posts, RR: 9
Reply 107, posted (1 year 7 months ago) and read 4181 times:

But you're proving the argument without realizing it, with yet another unit with another relation to other units complicating things further. Do you often measure things with you stretched arms ? The fact is, whatever the unit, you will either have a good idea of its size when rough is enough, and when it isn't you won't be able to use your own body to know the exact size of the unit so that relationship doesn't help.

I have no idea how the conversion went for people used to old units at the time, but I've never heard someone with no notion of imperial/standard units (meaning most people I know) complain about the size of the mètre.



New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
User currently offlineronglimeng From Canada, joined Oct 2006, 624 posts, RR: 0
Reply 108, posted (1 year 6 months 4 weeks 1 day 15 hours ago) and read 4129 times:

In the "imperial" system of units, we also have the "yard" which I don't think anyone has mentioned above. The yard is very roughly equivalent to the metre.

The yard is used very little compared to the "foot" for the same reason I think that some of us are saying the metre is inconvenient - it's just too long to conveniently estimate everyday (if I can call them that) distances.

If I have to be more precise than measuring to the nearest foot - i.e. using feet and inches, then I'll gladly reach for my metric measuring tape.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 109, posted (1 year 6 months 4 weeks 22 hours ago) and read 4061 times:

Quoting cmf (Reply 106):
France did not have a unified system but the French foot you referenced was some 10% longer than the current standardized international foot. Interestingly the international foot is not defined based on any of the natural measurements you reference but on the.... meter

Sorry that we're so often at cross purposes, cmf. Of course 'feet' varied somewhat from country to country - but my substantive point was that a high proportion of European countries used 'a species of foot' until at least 1848. As a matter of fact, the English, unlike most of Europe, set to work to standardise 'weights and measures' very early on; starting, in fact, in the 14th. century, when they began progressively to define 'feet' and other measurements, and enforce them by law. They also issued 'official' measures - basically lengths of hard metal - and distributed them to county and town halls everywhere. So the British 'foot' was first defined in the late 14th. century, and hasn't changed since; and all other measurements were eventually defined and enforced by law in a similar way. I've already mentioned the (66-foot/22-yard) 'Gunter's chain' - designed to 'accommodate' the rise of metric measurements - which was perfected by 1620, and is still in use without modification today.

So the foot was not 'defined' by the international convention you mention - nor was the metre. The convention just set out to measure and 'compare' both imperial and metric dimensions as accurately as possible. The metric equivalent of the yard, of course, turned out to be 0.9144m. - 'drowning in decimals' as usual!  

Oddly enough, I think a lot of the difference between us arose from the fact that Britain basically consists of a (relatively small, but fertile) island; so that, for many centuries, it was continually invaded from outside. In the end that meant that the British had to develop a big navy to defend themselves, and also a big merchant fleet to allow overseas trade. Following on from that, they inevitably had play a leading part in the development of navigation - which, of course, is based on degrees, minutes, and seconds, and works in sixties rather than hundreds.......  

With hindsight, as I implied, had the Paris lot 'corresponded' with the rest of Europe, they might have decided on a compromise - perhaps some sort of 'ninety-millimetre' foot - which could then eventually have been standardised across Europe and the world. But the problem they faced was that, thanks to Napoleon, Britain and France were at war most of the time - so there was no way they could have 'consulted' Britain. And, as I've implied, with Bonaparte running the show, they were probably under some pressure to make sure that whatever they came up with, it was fundamentally different from the imperial system anyway........

Quoting Aesma (Reply 107):
Do you often measure things with you stretched arms ?

Bit of a misunderstanding, Aesma. The 'arm's length' thing would have been very early on, before proper measuring devices were available, especially to non-military people like fishermen. The 'fathom,' six feet, was nevertheless a very sensible measure in the circumstances; basically, I expect that it was 'selected' because if, for example, you were in a boat hauling an anchor-cable inshore, a six-foot measurement would mean that it was far too early to jump out of the boat!

Quoting ronglimeng (Reply 108):
If I have to be more precise than measuring to the nearest foot - i.e. using feet and inches, then I'll gladly reach for my metric measuring tape.

Exactly so, ronglimeng, I do the same.

[Edited 2012-09-22 00:17:03]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlinedcann40 From United States of America, joined Sep 2012, 303 posts, RR: 0
Reply 110, posted (1 year 6 months 4 weeks 15 hours ago) and read 4025 times:

All I can add to this thread at this point is that I am learning a lot about a topic I am very interested in!

User currently offlineKen777 From United States of America, joined Mar 2004, 8045 posts, RR: 8
Reply 111, posted (1 year 6 months 4 weeks 13 hours ago) and read 3991 times:

Quoting MadameConcorde (Reply 47):
That for me is a good enough reason to think the whole world should change to the metric system once and for all.

It is basically a matter of costs for conversions and long term costs

Quoting Klaus (Reply 53):
There is zero sense in keeping the imperial system around.

Besides the costs of conveying, there are the related cost increases - a petrol tax increase of 1¢ per liter or 1¢ per gallon.

Or a car being devalued more because the odometer reads 100000. (Happened to my wife trading in our first "metric" car in Australia.)

Quoting cmf (Reply 103):
Keep in mind that this isn't about the metric system being superior in every regard. It is about the advantages of standardization

When a few hundred million are used to Imperial for daily living there is absolutely no reason to spend money to change. That money is better spent on things like cancer research. There is zero advantage in paying out a mountain to move to metric simply to have "standardization in daily living".

Speaking of costs to convert - how long did it take (and how much did it cost) for carpet manufacturers to convert from Imperial to metric in Australia/New Zealand?


User currently offlineeinsteinboricua From Puerto Rico, joined Apr 2010, 2677 posts, RR: 8
Reply 112, posted (1 year 6 months 4 weeks 7 hours ago) and read 3949 times:

After years of using metric in science courses, I think metric should be the way to go. It's gonna take some time to get used to it, but we can manage. But I really don't see the point of teaching metric units in science courses and having daily life in others.


"You haven't seen a tree until you've seen its shadow from the sky."
User currently offlineKen777 From United States of America, joined Mar 2004, 8045 posts, RR: 8
Reply 113, posted (1 year 6 months 4 weeks 6 hours ago) and read 3937 times:

Quoting einsteinboricua (Reply 112):
But I really don't see the point of teaching metric units in science courses and having daily life in others.

Why not?

Many communities, including science & medicine, have used metric at work without a problem - then gone home, driving at 35 in 85 degree heat on their 6 mile commute.

BTW, is rugby played on a metric or imperial field?


User currently offlineWrenchBender From Canada, joined Feb 2004, 1779 posts, RR: 9
Reply 114, posted (1 year 6 months 4 weeks 5 hours ago) and read 3929 times:

Quoting Ken777 (Reply 113):
BTW, is rugby played on a metric or imperial field?

Metric, What was 25 yd line is now the 22 M line etc, the lineouts take place between 5 and 15 M from touch and 10 M is the minimum distance for a kickoff.

WrenchBender



Silly Pilot, Tricks are for kids.......
User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 115, posted (1 year 6 months 4 weeks 5 hours ago) and read 3930 times:

Quoting NAV20 (Reply 109):
Of course 'feet' varied somewhat from country to country

Not to mention between cities. The longest fr is more than 30% longer than the shortest. Rather large difference.

As to the current (International) ft being normal. On average a humans feet are 15.3% of their length. It means you should be 2 m for your feet to be "right".

The average in Netherlands, a country with tall population, is 183 cm indicating their feet are 280 mm on average. The error to the international ft is almost the same as the yard "error" to meter.

Quoting NAV20 (Reply 109):
a high proportion of European countries used 'a species of foot' until at least 1848

Many after that.

Quoting NAV20 (Reply 109):
So the foot was not 'defined' by the international convention you mention - nor was the metre. The convention just set out to measure and 'compare' both imperial and metric dimensions as accurately as possible. The metric equivalent of the yard, of course, turned out to be 0.9144m. - 'drowning in decimals' as usual!

The international foot was standardized in 1959 to exactly 0.9144 m, no drowning in additional decimals.

"To secure identical values for the yard and pound in precise measurements, and international yard and international pound were adopted by agreement between the directors of the national standards laboratories of the six English-speaking nations: Canada, New Zealand, United States, United Kingdom, South Africa, and Australia.According to the agreement, the international yard equals 0.9144 meter"
http://books.google.com/books?id=4aW...RV1AoC&pg=PA13#v=onepage&q&f=false

Quoting NAV20 (Reply 109):
which could then eventually have been standardised across Europe and the world

Meter is the standard in all but USA, Burma and Liberia.

Quoting Ken777 (Reply 111):
It is basically a matter of costs for conversions and long term costs

That is half the equation. The other part is future savings.

Quoting Ken777 (Reply 111):
When a few hundred million are used to Imperial for daily living there is absolutely no reason to spend money to change. That money is better spent on things like cancer research. There is zero advantage in paying out a mountain to move to metric simply to have "standardization in daily living".

Completely wrong. You are neglecting the enormous amount of extra work taking place every day because there are two systems.

Quoting Ken777 (Reply 111):
Speaking of costs to convert - how long did it take (and how much did it cost) for carpet manufacturers to convert from Imperial to metric in Australia/New Zealand?

Please tell me. Please also tell me how much it cost them and other manufacturers in lost export or in additional cost by using two systems.

And while not good for carpet manufacturers i'm sure consumers appreciate when prices are adjusted per m2 instead of ft2.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 116, posted (1 year 6 months 3 weeks 6 days 23 hours ago) and read 3890 times:

Quoting Ken777 (Reply 111):
Speaking of costs to convert - how long did it take (and how much did it cost) for carpet manufacturers to convert from Imperial to metric in Australia/New Zealand?

Can't answer the question, Ken777, since the conversion is still in its infancy really. Full 'metrication' was not given legal effect here until 1988 (I think) and those huge machines don't wear out that quickly. Most carpet therefore still comes 12 feet wide. Or 3.6576 metres wide, if you prefer.  

Same sort of thing in the construction industry, particularly things like timber. The machines haven't changed much. In addition, considerable use is made of the 'metric foot' (30 centimetres) which is almost exactly the same as the imperial foot:-

"A metric foot is a nickname occasionally used in the United Kingdom for a length of 300 millimetres (30 cm). A metric foot can be divided into twelve "metric inches" of 25 millimetres (2.5 cm) each. The metric foot and inch are therefore 4.8 and 0.4 millimetres (or about 1⁄60) shorter than an imperial foot and inch respectively.

"The term "metric foot" does not appear in any British Standard. The practice of choosing multiples of 300 mm and 600 mm as preferred dimensions in the construction industry originated from the international standard on modular coordination (ISO 2848). These numbers were chosen because of their large number of divisors. Any multiple of 600 mm can be evenly divided into 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 25, 30, etc. parts."


http://en.wikipedia.org/wiki/Metric_foot

Needless to say, the largely-useless metre barely figures at all in most fields.........

[Edited 2012-09-22 23:35:02]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineKen777 From United States of America, joined Mar 2004, 8045 posts, RR: 8
Reply 117, posted (1 year 6 months 3 weeks 6 days 13 hours ago) and read 3834 times:

Quoting cmf (Reply 115):
That is half the equation. The other part is future savings.

So we spend millions changing every speed limit sign in the US. What savings would that deliver to us?

Quoting cmf (Reply 115):
Please tell me. Please also tell me how much it cost them and other manufacturers in lost export or in additional cost by using two systems.

It doesn't cost them anything. They keep making some pretty nice carpets and they sell.

Quoting cmf (Reply 115):
You are neglecting the enormous amount of extra work taking place every day because there are two systems.

It wasn't that hard for me to use the 3 Ft wide shade cloth when building a pergola many years ago in PER. I simply spaced the wood beams at the necessary distance.

Quoting NAV20 (Reply 116):
Can't answer the question, Ken777, since the conversion is still in its infancy really.

The Aussie's were going strong when we moved there in '76. Big money had been spent (like speed limit signs) and the government was pushing hard for the conversion. So hard, in fact , that journalists were converting to metric, even within quotation marks. My all time favorite was the fisherman talking about the "3.6576 meters shark" The journalist went to 4 decimal places to ensure the quote was not really a proper quote.

Quoting cmf (Reply 115):
Completely wrong. You are neglecting the enormous amount of extra work taking place every day because there are two systems.

Having lived in both environments I think you are overstating the issue. Professionals work in the system standard to them and those who don't need the metric system here simply don't worry about it.

BTW, when we moved to PER the wife would order a pound of hamburger at the butchers and they guys never had a problem filling the order. Same with steaks ordered at an inch, or inch & a half. It was not an enormous amount of extra work for the butcher.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 118, posted (1 year 6 months 3 weeks 5 days 22 hours ago) and read 3772 times:

Quoting Ken777 (Reply 117):
the wife would order a pound of hamburger at the butchers and they guys never had a problem filling the order.

'Too right,' Ken777.  

Mind you, back in those days, the 'metric switch' nearly cost me my life on one occasion. I needed a bit of (quite expensive) copper pipe to repair our central heating system. The guy asked how long I wanted it and I said, 'Say a foot." His reply was, 'Metric mate, got to work in metric now......" So (measurements being a big part of my working life in those days) I couldn't resist saying, "OK, three hundred and four point eight millimetres then......"

His eyes darkened and, for a moment, I thought he was going to thump me. Trouble was, he was the original 'metric man' - about two metres tall, one metre wide, and weighing about 90.71kgs. (200 pounds).  

Luckily he realised in the nick of time that I was 'pulling his leg,' and we had a laugh together.......  

[Edited 2012-09-24 00:15:14]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 119, posted (1 year 6 months 3 weeks 5 days 16 hours ago) and read 3729 times:

Quoting Ken777 (Reply 117):
So we spend millions changing every speed limit sign in the US. What savings would that deliver to us?

The objectors SOP. Find an isolated example and pretend it is indicative for the total.

The savings is in standardization.

Quoting Ken777 (Reply 117):
It doesn't cost them anything. They keep making some pretty nice carpets and they sell.

It cost them by limiting where they can sell.

Quoting Ken777 (Reply 117):
It wasn't that hard for me to use the 3 Ft wide shade cloth when building a pergola many years ago in PER. I simply spaced the wood beams at the necessary distance.

Of course it isn't hard. Both systems work perfectly fine. It is having multiple systems that is the problem.

Quoting Ken777 (Reply 117):
The Aussie's were going strong when we moved there in '76. Big money had been spent (like speed limit signs) and the government was pushing hard for the conversion. So hard, in fact , that journalists were converting to metric, even within quotation marks. My all time favorite was the fisherman talking about the "3.6576 meters shark" The journalist went to 4 decimal places to ensure the quote was not really a proper quote.

It is easy to ridicule anything. Being productive takes honesty.

Quoting Ken777 (Reply 117):
Having lived in both environments I think you are overstating the issue. Professionals work in the system standard to them and those who don't need the metric system here simply don't worry about it.

Having lived in both environments and more importantly worked in areas where we had to maintain both systems I can tell you there are a lot of costs involved.

Quoting Ken777 (Reply 117):
BTW, when we moved to PER the wife would order a pound of hamburger at the butchers and they guys never had a problem filling the order. Same with steaks ordered at an inch, or inch & a half. It was not an enormous amount of extra work for the butcher.

Again, poor example. For the opposite extreme look at the Mars Climate Orbiter.


Reality is that we are working around it but there is a lot of wasted time and resources because there are two parallel systems. Each time there is a conversion there is added opportunity for mistakes. Add the way distances are rounded and you have a "natural" error. If there was a clear benefit it would be fine but in the end the only real benefit is that people are used to it.


User currently offlineGrahamHill From France, joined Mar 2007, 2750 posts, RR: 1
Reply 120, posted (1 year 6 months 3 weeks 5 days 12 hours ago) and read 3694 times:

Quoting NAV20 (Reply 118):
Mind you, back in those days, the 'metric switch' nearly cost me my life on one occasion

On a more serious note, the metric switch almost cost the life of 69 people of Air Canada's Flight 143, on 23rd July 1983.

http://en.wikipedia.org/wiki/Gimli_Glider



"A learned fool is more foolish than an ignorant one" - Moliere
User currently offlinecanoecarrier From United States of America, joined Feb 2004, 2828 posts, RR: 12
Reply 121, posted (1 year 6 months 3 weeks 5 days 10 hours ago) and read 3663 times:

Quoting NAV20 (Reply 52):
The British/Commonwealth surveying ('Gunter's') chain, of course, is an oddity in its own right - given that it's sixty-six feet long, and has a hundred links......... But it's a damn sight lighter to carry around than the (100-foot) 'Engineer's' chain. And, of course, it fits in with the traditional British (and Commonwealth, and US) agricultural area measurement, the acre. One acre equals 4,840 square yards, 43,560 square feet.

If you want that in metric, an acre is 4,046.8564224 square metres, or 0.40468564224 of a hectare. Given that most land sales in Britain are still based on acreage, as they have been since the Middle Ages, you can probably see why they've so far been reluctant fully to embrace the Metric System!

It seems you're the only one talking about land measurement, so I'll address it to you Nav.

For the better part of my professional career I've worked with the US acre measurement system. Personally, I think it works really well in rural areas where a "Section" is a mile by a mile (640 +/- acres). It divides well into quarter sections as 1/4 mile by a 1/4 mile (160 acres), or 40 acres (1/16th mile/1/16th mile). When I started my career as a forester we used to learn surveying with a gunter's chain, which is now made of sprung steel, but has almost completely been replaced with optical measuring equipment.

That system is much more difficult to work with in urban areas, but not impossible.

Having never worked with metric land surveying I'd be interested just how easy it is to work in hectares when compared to the US system.



The beatings will continue until morale improves
User currently offlineKen777 From United States of America, joined Mar 2004, 8045 posts, RR: 8
Reply 122, posted (1 year 6 months 3 weeks 5 days 10 hours ago) and read 3657 times:

Quoting cmf (Reply 119):
The objectors SOP. Find an isolated example and pretend it is indicative for the total.

The theory of a conversion is in the arguments, the actual conversion is a cost based operation and that cost can easily blow past initial estimates.

I simply do not see the value of spending money to tell me to drive 60 instead of 35. Maybe when out $15 Trillion drbt is paid off we can look at it again.

(BTW. Want another? All those cookbooks that have measurements and temps in Imperial - all of a sudden a real pain for hte cooks at home who have to have conversions. )

Quoting cmf (Reply 119):
It is having multiple systems that is the problem.

Metric has been used in various fields for all of my 68 years, right alongside of Imperial, without any major problems. I think the issue is more in your head than in the communities that manage both systems with ease.

Quoting GrahamHill (Reply 120):
On a more serious note, the metric switch almost cost the life of 69 people of Air Canada's Flight 143, on 23rd July 1983.

I remember reading about that, along with the fact that no pilot had been able to repeat that successful landing when given the problem in a simulator.

Any other pilot and the conversion to metric may have been far more expensive for Canada than it was.


User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 123, posted (1 year 6 months 3 weeks 5 days 8 hours ago) and read 3640 times:

Quoting Ken777 (Reply 122):
The theory of a conversion is in the arguments, the actual conversion is a cost based operation and that cost can easily blow past initial estimates.

Conversion costs are one time. Savings are perpetual.

Quoting Ken777 (Reply 122):
I simply do not see the value of spending money to tell me to drive 60 instead of 35. Maybe when out $15 Trillion drbt is paid off we can look at it again.

There is no saving when you compare driving 60 km/h to 35 mph. The saving is in being consistent.

Take something as simple as adding up a few distances:

Which do you calculate fastest in your head?

920.75 + 1 544.64 = ?

3' 2 1/2" + 5' 8 1/8" = ?

You can't even enter the second easily in Excel...

How much do you think it costs that people can't do in their head verification that the result presented makes sense?

Then there are the extra costs when having to deal with a second system because customers require it.

Quoting Ken777 (Reply 122):
(BTW. Want another? All those cookbooks that have measurements and temps in Imperial - all of a sudden a real pain for hte cooks at home who have to have conversions. )

There are more chefs using metric than imperial.

Quoting Ken777 (Reply 122):
Metric has been used in various fields for all of my 68 years, right alongside of Imperial, without any major problems.

Without any problems? How about AC143 you referenced next in your post. How about the many other published and not published problems?

How much have faulty conversions between imperial units cost? No-one knows but just about anyone using them know of more or less costly examples.

Quoting Ken777 (Reply 122):
I think the issue is more in your head than in the communities that manage both systems with ease.

I think you fail to see where costs of systems arise.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 124, posted (1 year 6 months 3 weeks 5 days 1 hour ago) and read 3599 times:

Quoting canoecarrier (Reply 121):
I'd be interested just how easy it is to work in hectares when compared to the US system.

In my day no-one ever did it, canoecarrier - like the metre itself, the hectare (2.47 acres) was far too big to be useful; and both measures had the added disadvantage that even if the professionals could get their brains more or less in tune with metric measurements, 'Joe Public' was completely confused by them. So, until I retired anyway, normal practice was to go on using square feet, square yards, acres etc., but put the equivalent metric figures in brackets after the imperial ones.

The metre had another disadvantage, too. If the marketing guys proposed a CBD office rent of say $30 per square foot, that was readily understood by the prospective tenant. But if they'd said $323 per square metre instead, human nature being what it is, the tenant would think that was higher.......  

In addition, I've noticed that Australian retailing, anyway, appears to be well on the way to phasing out the metre and substituting the 'metric yard,' 900mm. - google brings up all these examples:-

http://www.google.com.au/#hl=en&rlz=...&bav=on.2,or.r_gc.r_pw.r_qf.&cad=b

That would be the best answer to the problem really - to 'imperialise' the metre, make it 900mm., virtually an old-fashioned yard. If nothing else, it would save a lot of the ink that is currently used typing in all those noughts and decimals!  



"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineGrahamHill From France, joined Mar 2007, 2750 posts, RR: 1
Reply 125, posted (1 year 6 months 3 weeks 4 days 15 hours ago) and read 3537 times:

Quoting NAV20 (Reply 124):
to 'imperialise' the metre

NAV20, reading all your posts, I think the best solution for you is that Australia reverts to the Imperial system...  



"A learned fool is more foolish than an ignorant one" - Moliere
User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 126, posted (1 year 6 months 3 weeks 4 days 14 hours ago) and read 3528 times:

Quoting NAV20 (Reply 124):
So, until I retired anyway, normal practice was to go on using square feet, square yards, acres etc., but put the equivalent metric figures in brackets after the imperial ones.
Quoting NAV20 (Reply 124):
The metre had another disadvantage, too. If the marketing guys proposed a CBD office rent of say $30 per square foot, that was readily understood by the prospective tenant. But if they'd said $323 per square metre instead, human nature being what it is, the tenant would think that was higher.......

Funny how when it is renting space the lower unit is good but when it comes to cost of fuel the lower number is bad...

Quoting NAV20 (Reply 124):
google brings up all these examples:-

LOL Look at the width of those type of appliances in other countries, they are not a meter. Nor are they a yard in US. I'm sure you can find an exemption somewhere but it will be just that, an exemption.

All in all your complaints is nothing but reluctance to change. Countries using metric function perfectly fine. Time to take the full step. Give up the crying towel and join the rest of the world.

Maybe you want to use Australian pound in parallel with the dollar...


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 127, posted (1 year 6 months 3 weeks 4 days 14 hours ago) and read 3539 times:

Hi, GrahamHill.   My point was that, due to the inadequacies of the metric system, we seem to have pretty well done that already.  

300mm. is a foot, and 900mm. is a yard, as near as dammit........

No-one ever mentions the 'decimetre' any more, and even the centimetre is 'dead on its feet.' All that's left really is the metre - and even that doesn't get mentioned a lot nowadays. In my view even the metre's days are numbered.

I really think that we're facing a future largely measured in millimetres.......  

Funnily enough, most Australians couldn't wait to switch to metric, because they somehow felt that it was 'modern.' Silly really, given that it was invented (devised?) by an obscure group of mathematicians as long ago as the 1790s.....

But it'll pass. We'll get used to the 300mm. foot and the 900mm. yard, things will settle down, and life will go on. And the guys who manufacture printing ink will have the time of their lives......  

PS - cmf, there's no Australian pound, it's dollars now. Worth quite a lot more than the US one, if it matters......

[Edited 2012-09-25 07:58:04]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineGrahamHill From France, joined Mar 2007, 2750 posts, RR: 1
Reply 128, posted (1 year 6 months 3 weeks 4 days 14 hours ago) and read 3509 times:

Quoting NAV20 (Reply 127):
300mm. is a foot, and 900mm. is a yard, as near as dammit........

You obviously grew up with the Imperial, hence that perspective that you constantly keep in mind. We, the people who grew up with the metric, don't make any parallel with the foot or the yard. It's not relevant. A metre is a metre  . If we want to estimate a length shorter than a metre, we're going to use the double figure in centimetre (10 cm, 20 cm, 30 cm, 40 cm, etc.).

But for the people who grew up with the Imperial and had to switch to metric, I understand it is troublesome.

Quoting NAV20 (Reply 127):
No-one ever mentions the 'decimetre' any more, and even the centimetre is 'dead on its feet.' All that's left really is the metre - and even that doesn't get mentioned a lot nowadays. In my view even the metre's days are numbered.

I agree for the decimetre, but the centimetre is used all the time. Maybe in Australia, it's different?

And the metre's days might be numbered in Australia, but that's all. We like the unit and we'll keep it forever  
Quoting NAV20 (Reply 127):
Silly really, given that it was invented (devised?) by an obscure group of mathematicians as long ago as the 1790s.....

Thank God for that "obscure" group of mathematicians, then  

Oh, and you might want to stop using the millimetre to convert a foot or a yard into the metric system, and use the centimetre instead. I think it helps better comprehend the conversion. In Europe, a foot is roughly 30 cm and a yard roughly 90 cm. We don't use the millimetre because it gives a too big number and therefore a false perspective of what the distance or the length is really  

[Edited 2012-09-25 08:36:39]


"A learned fool is more foolish than an ignorant one" - Moliere
User currently offlineKen777 From United States of America, joined Mar 2004, 8045 posts, RR: 8
Reply 129, posted (1 year 6 months 3 weeks 4 days 13 hours ago) and read 3504 times:

Quoting cmf (Reply 123):
There is no saving when you compare driving 60 km/h to 35 mph. The saving is in being consistent.

Actually I'm pretty consistent - I use cruise control a lot.

I can also press a button on the dash & the dashboard converts to metric

I see no value in converting every street in the US to metric. That is a huge cost and it can be confusing for many. Just look to AC143 for potential confusions.

Quoting cmf (Reply 123):
You can't even enter the second easily in Excel...

Why would you want to? You can pretty easily see the answer.

Quoting cmf (Reply 123):
There are more chefs using metric than imperial.

And there are more cooks in American kitchens using Imperial.

Quoting cmf (Reply 123):
How about AC143 you referenced next in your post

That was a pretty clear example of the risks & costs of the conversion Canada was undergoing. Without the skills of that one pilot the costs of Canada's conversions would have been far higher.

You'll notice that the link used feet for altitude - with conversions for people who don'y understand feet. And the problem arose in the first place because of the change to metric.

Quoting cmf (Reply 123):
I think you fail to see where costs of systems arise.

We almost saw some unexpected costs in Canada.

If you look at another industry - home building. There can be some benefits to the builder in calculating various costs - especially beneficial to the less experienced builder. But many parts, like carpets, will continue on being delivered on an imperial measurement.

And when working with the average buyer the measurements will still need to be converted for ease of understanding during the design phase. Just like ordering a pound of hamburger.


User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 130, posted (1 year 6 months 3 weeks 4 days 6 hours ago) and read 3453 times:

Quoting Ken777 (Reply 129):
Actually I'm pretty consistent - I use cruise control a lot.

Great, I'm sure it is handy when you pick your nose. As to the topic at hand it has no relevance.

Quoting Ken777 (Reply 129):
I see no value in converting every street in the US to metric. That is a huge cost and it can be confusing for many.

Signs are replaced every couple of years anyway so it isn't that much of a cost. Having multiple systems with identical names representing different quantities is confusing.

Quoting Ken777 (Reply 129):
Just look to AC143 for potential confusions.

A perfect example why we must stop the lunacy of multiple parallel systems.

Quoting Ken777 (Reply 129):
That was a pretty clear example of the risks & costs of the conversion Canada was undergoing. Without the skills of that one pilot the costs of Canada's conversions would have been far higher.

Yes it is a clear example of the problems with multiple systems. There has been problems due to converting between Imperial and US customary too. A big part of why the metric system was created.

Quoting Ken777 (Reply 129):
You'll notice that the link used feet for altitude - with conversions for people who don'y understand feet. And the problem arose in the first place because of the change to metric.

No, the problem arose in the first place because there are multiple parallel systems.

Quoting Ken777 (Reply 129):
We almost saw some unexpected costs in Canada.

We see real costs every day because time and resources are wasted in conversions, duplication and the unfortunate errors that happens ever so often.

Quoting Ken777 (Reply 129):
If you look at another industry - home building. There can be some benefits to the builder in calculating various costs - especially beneficial to the less experienced builder. But many parts, like carpets, will continue on being delivered on an imperial measurement.

There was a time when people in Europe considered the New Year to start in March. After it changed to Jan 1st some people insisted to continue to celebrate new year in March. Not many of them left today. I consider the people sticking to the imperial units to be pretty much as those who kept celebrating New Year in March.

The ease of calculation is a major advantage with the metric system and the advantage is for everyone. Imperial names may continue to be used but the measurements will be adjusted. It is just a matter of time.

Quoting Ken777 (Reply 129):
Just like ordering a pound of hamburger.

The average buyer does not order a pound of hamburger. The average buyer order 500g or half a kg. The average buyer doesn't know how much a pound of hamburger meat is . They know it as that historic unit USA insist on using but have no idea what weight it represents.


User currently offlineKen777 From United States of America, joined Mar 2004, 8045 posts, RR: 8
Reply 131, posted (1 year 6 months 3 weeks 4 days 3 hours ago) and read 3429 times:

Quoting cmf (Reply 130):
A perfect example why we must stop the lunacy of multiple parallel systems.

The parallel systems was not the problem - aviation has been successfully using Imperial from Day One.

It was simply the confusion related to an unnecessary conversion to metric.

Quoting cmf (Reply 130):
We see real costs every day because time and resources are wasted in conversions, duplication and the unfortunate errors that happens ever so often.

And how much are you willing to have you income (and other) taxes increased to pay for this conversion. I'm not willing to spend a cent when more money is needed for education, medical research, etc. Let's let the ones who want to have the money spent actually deliver the money. And, after a few years of throwing money away, you'll discover that most Americans haven't bothered with the long list of stuff that has to be changed,


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 132, posted (1 year 6 months 3 weeks 4 days 1 hour ago) and read 3415 times:

Quoting GrahamHill (Reply 128):
Oh, and you might want to stop using the millimetre to convert a foot or a yard into the metric system, and use the centimetre instead.

GrahamHill, the reason that most people here (and no doubt in the UK) tend to go straight to millimetres is that it gives us our inch back, as well as the foot and the yard.   Basically 25 millimetres is an inch - 12 times 25 gives 300 (the foot) - and times 3 gives 900 (the yard).

Don't forget that imperial measurements will still be required for many purposes, for an indefinite period. Imagine, for example, that you were extending or repairing a house. All the key measurements, like the size of the bricks, the tiles, and the timber, will be in imperial; no use 'going metric' on that, nothing would fit........ The centimetre, like the metre, doesn't remotely fit our needs in that sort of situation - better to leave the thing out of it and 'keep it simple' by just using multiples of millimetres.

I mentioned that Australians tend to be unduly impressed by anything they consider to be 'modern.' That's how we got stuck with the metric system in the first place. Thankfully, though, they tend to be pretty good 'improvisers' too; which is why we've been able to 'imperialise' metric measurements so quickly, and keep our economy rolling.......



"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineGrahamHill From France, joined Mar 2007, 2750 posts, RR: 1
Reply 133, posted (1 year 6 months 3 weeks 4 days ago) and read 3407 times:

Quoting NAV20 (Reply 132):
GrahamHill, the reason that most people here (and no doubt in the UK) tend to go straight to millimetres is that it gives us our inch back, as well as the foot and the yard.   Basically 25 millimetres is an inch - 12 times 25 gives 300 (the foot) - and times 3 gives 900 (the yard).


But you could argue that 2.5 cm is an inch, that 120 times gives you 300, and that times 3 gives you 900 

(ok ok, just pulling your leg here  )

Quoting NAV20 (Reply 132):
Don't forget that imperial measurements will still be required for many purposes, for an indefinite period. Imagine, for example, that you were extending or repairing a house. All the key measurements, like the size of the bricks, the tiles, and the timber, will be in imperial;


I really don't know how you can live using both system, to be honest. It's like in Canada. Canada is officially metric, but if you tell someone you're 1.83 m and 80 kg, they look at you like you're trying to explain them quantum mechanics...   



"A learned fool is more foolish than an ignorant one" - Moliere
User currently offlineJJJ From Spain, joined May 2006, 1718 posts, RR: 1
Reply 134, posted (1 year 6 months 3 weeks 3 days 22 hours ago) and read 3397 times:

Quoting NAV20 (Reply 132):
the tiles, and the timber, will be in imperial; no use 'going metric' on that, nothing would fit........

I've worked for many years in the tile industry (inc, Australia) and can tell you that the vast majority of tiles in Australia are actually made metric, then hastily converted to inches for retail.

4'x4' tiles are actually built to 10x10cm. specifications, for example.


User currently offlinestealthz From Australia, joined Feb 2005, 5609 posts, RR: 45
Reply 135, posted (1 year 6 months 3 weeks 3 days 21 hours ago) and read 3385 times:
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Quoting NAV20 (Reply 124):
In addition, I've noticed that Australian retailing, anyway, appears to be well on the way to phasing out the metre and substituting the 'metric yard,' 900mm. - google brings up all these examples:-

Not sure what this "metric yard" thing is you talk about, first time I heard of it was here.
I understand that many of the links in your search mention "900 mm" (didn't see many refer to metric yard) but I don't see how that makes your case for the demise of the meter in Australia. The google search you posted above used "Australia 900 mm" as the search criteria, a similar search substituting 800 mm also turned up a large number of products, where does the oh so neat conversion of 800 mm into 31 1/2 inches( or 2 ft 7 1/2 inches) fit into your metric foot/yard theory?
One of the links in your google search advertises a 900 mm Smeg oven, a quick look at the Smeg website shows they make ovens and other appliances in a whole range of sizes

I know in my business if I started abandoning the metre and adopting the "metric yard" that you say is common here, I would not be in the business long.

Quoting NAV20 (Reply 127):
No-one ever mentions the 'decimetre' any more, and even the centimetre is 'dead on its feet.' All that's left really is the metre - and even that doesn't get mentioned a lot nowadays. In my view even the metre's days are numbered.
Quoting GrahamHill (Reply 128):
I agree for the decimetre, but the centimetre is used all the time. Maybe in Australia, it's different?

And the metre's days might be numbered in Australia, but that's all. We like the unit and we'll keep it forever

The centimetre was never a valid term in Australia when converting to metric, rulers etc were only in mm, the term has been used a lot in Australia though and rulers, tape measures etc are now sold marked in cm(also now available with inch markings as well but that was illegal for some years).
Not sure I ever heard the term decimetre in Australia more than a couple of times.

Not sure what Australia Nav20 lives in that hardly mentions the metre... It is used a lot in my Australia and is here to stay.

[Edited 2012-09-26 01:16:46]


If your camera sends text messages, that could explain why your photos are rubbish!
User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 136, posted (1 year 6 months 3 weeks 3 days 18 hours ago) and read 3357 times:

Quoting Ken777 (Reply 131):
It was simply the confusion related to an unnecessary conversion to metric.

Correct, there should not have been any conversion. It should have been metric from the beginning.

Quoting Ken777 (Reply 131):
And how much are you willing to have you income (and other) taxes increased to pay for this conversion.

Wrong question. The question is: how much longer are you prepared to have your purchase power reduced because you must support all duplication, conversions and errors?


User currently offlineMD11Engineer From Germany, joined Oct 2003, 13797 posts, RR: 63
Reply 137, posted (1 year 6 months 3 weeks 3 days 17 hours ago) and read 3345 times:

Here the pound (Pfund) got seamlessly translated into metric: If somebody orders a "Pfund" of minced meat at the buth

Quoting cmf (Reply 130):
Quoting Ken777 (Reply 129):
Just like ordering a pound of hamburger.

The average buyer does not order a pound of hamburger. The average buyer order 500g or half a kg. The average buyer doesn't know how much a pound of hamburger meat is . They know it as that historic unit USA insist on using but have no idea what weight it represents.

Here if I go to the butcher´s and order a "Pfund" (pound) of minced meat, I´ll get 500 grammes (0.5 kg). The old non-metric unit Pfund has simply been used for the closest sensible metric equivalent. It is not an official unit, but gets used in daily life. Similarly, when we still had the old D-Mark, a "Pfund" was a slang term for a 20 Mark bill, same as the term "Groschen" (a really obsolete currency) was used for the 10 Pfennig coin ( 0.10 D-Mark).

Jan


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 138, posted (1 year 6 months 3 weeks 3 days 16 hours ago) and read 3331 times:

Quoting stealthz (Reply 135):
Not sure what this "metric yard" thing is you talk about, first time I heard of it was here.

As I've said, stealthz, I was involved in property development in the 'transition period' before the metric system became the official measurement. The architects and engineers were in a particular fix - trying to 'convert' to the metre, but finding it very difficult to use. In the first place it was far too big - they were used to feet and square feet - and, secondly, it was largely 'indivisible' - you could only divide it by two or five.

So quite a few buildings got designed on the basis of the 'metric foot,' 300mm. - which was, of course, a much more convenient size, and much more divisible. Once the design was finished, of course, it was a simple matter to calculate the 'true' floor areas etc. in the 'official' square metres (long strings of decimals and all  ). Though a lot of my work involved negotiations with Americans wanting to set up in Australia, they wouldn't talk in anything BUT square feet at ANY time..... Exciting - though complicated - times.......  http://en.wikipedia.org/wiki/Metric_foot

That remains a continuing problem - the metre/sq. metre remain just plain too 'big' for efficient use in the property field. So is the hectare. Makes me glad that I'm retired........  

[quote=GrahamHill,reply=133]if you tell someone you're 1.83 m and 80 kg, they look at you like you're trying to explain them quantum mechanics

Maybe it's because you're giving them a wrong measurement, GrahamHill. Six feet isn't 1.83m., it's 1.8288m.  

[Edited 2012-09-26 06:26:54]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlineGrahamHill From France, joined Mar 2007, 2750 posts, RR: 1
Reply 139, posted (1 year 6 months 3 weeks 3 days 15 hours ago) and read 3312 times:

Quoting stealthz (Reply 135):
The centimetre was never a valid term in Australia when converting to metric

Really? Why not?

Quoting stealthz (Reply 135):
Not sure I ever heard the term decimetre in Australia more than a couple of times.

Same in Europe (at least in France). Actually, the only thing I can remember is the nickname we give to a ruler. When we were at school, rulers were coming mostly in length of 20 cm and we used to call them a "double decimetre".

Quoting NAV20 (Reply 138):
Maybe it's because you're giving them a wrong measurement, GrahamHill. Six feet isn't 1.83m., it's 1.8288m

  

That must be the reason!



"A learned fool is more foolish than an ignorant one" - Moliere
User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 140, posted (1 year 6 months 3 weeks 3 days 15 hours ago) and read 3295 times:

Glad you liked the joke, GrahamHill. Looks like we both have what they used to call a 'mordant' sense of humour.

As to the centimetre, simple explanation. The metre/hectare didn't catch on because they were too damn big; the centimetre lost out because it was too b*****y small.......



"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 141, posted (1 year 6 months 3 weeks 3 days 15 hours ago) and read 3290 times:

Quoting NAV20 (Reply 140):
The metre/hectare didn't catch on because they were too damn big; the centimetre lost out because it was too b*****y small.......

Yet the rest of the world does just fine.


User currently offlineronglimeng From Canada, joined Oct 2006, 624 posts, RR: 0
Reply 142, posted (1 year 6 months 3 weeks 3 days 14 hours ago) and read 3280 times:

Quoting NAV20 (Reply 138):
Six feet isn't 1.83m., it's 1.8288m

I would say that 6 feet converts to 2 metres. You can't add more significant digits to the result of a calculation than existed with the starting number.

So in this case you can be more 'precise' with the single digit Imperial unit, than you can with the metrc unit.


User currently offlineDeltaMD90 From United States of America, joined Apr 2008, 7276 posts, RR: 52
Reply 143, posted (1 year 6 months 3 weeks 3 days 5 hours ago) and read 3225 times:

Quoting NAV20 (Reply 140):
As to the centimetre, simple explanation. The metre/hectare didn't catch on because they were too damn big; the centimetre lost out because it was too b*****y small.......

The more I read, the more I think that people growing up with the imperial system will generally find the cm too small and the m too big, while people growing up with the metric system would find the foot too short. Seems to be the trend I'm seeing... all on what you're used to



Ironically I have never flown a Delta MD-90 :)
User currently offlineKen777 From United States of America, joined Mar 2004, 8045 posts, RR: 8
Reply 144, posted (1 year 6 months 3 weeks 3 days 2 hours ago) and read 3198 times:

Quoting NAV20 (Reply 132):
I mentioned that Australians tend to be unduly impressed by anything they consider to be 'modern.'

Look how long the Kingswood lasted on the market.   

(Yes, I did own a very used Kingswood wagon. Paid $800 for it - I don't even remember the year, but it was old in '78)

Quoting GrahamHill (Reply 133):
Canada is officially metric, but if you tell someone you're 1.83 m and 80 kg, they look at you like you're trying to explain them quantum mechanics...  

Maybe if you told them in French . . .   

Quoting JJJ (Reply 134):
the vast majority of tiles in Australia are actually made metric, then hastily converted to inches for retail.

When I lived in Perth a very large amount of tiles sold were from Europe - especially the better ones.


User currently offlineQuokkas From , joined Dec 1969, posts, RR:
Reply 145, posted (1 year 6 months 3 weeks 3 days 1 hour ago) and read 3182 times:

Funny that when I look at prices quoted, I note that carpets are sold by the linear metre. Broadloom may be 3.6m wide but is sold by length in metres, not in feet or yard to metre equivalents, but in actual metres. Paving, floor and wall tiles are all sold by the square metre with actual tiles being available in various metric sizes.

Paint is sold in multiples of litres, you don't see it rounded to the nearest metric equivalent of pints, quarts or gallons, but actual volumes in litres. And while the odd farmer might still talk of half an inch of rain, the BOM and everyone else measures it in millimetres and even the odd farmer's rain gauge used to report to BOM calculates the fall in mm.

Even alcohol is sold in millilitres or litres and not imperial measures. Liquor sellers who use generic terms like "middy", "schooner" or "pot" (terms that are not legally defined) or "pint" must ensure that any advertising using such terms should also include the actual size of the glass (eg: ‘middy’ – 280 mL, or ‘schooner’ – 400 mL). Glasses must be marked to indicate either a brim or line measure in mL or L.

Sorry NAV20, I don't see metric falling out of use any time soon in Australia for the simple reason that the proportion of the population used to the old system is falling and there is no active push to reintroduce three barleycorns to the inch.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 146, posted (1 year 6 months 3 weeks 3 days ago) and read 3182 times:

Turns out that I may have been a bit unfair on those mathematicians! Their activities weren't the whole story.

We have a time-honoured wry saying in the Commonwealth - 'A camel is a horse designed by a committee.' And it turns out that the metric system was indeed designed by a committee. What's more, the process started very early on, about 1670. And the fundamental (and, to my mind, very silly) principle of basing the length of the main unit of measurement not on any existing system of measurement but on the length of part of a meridian of longitude, appears to have been proposed way back in 1720.

All sorts of 'faffing about' then ensued, for most of the 18th. Century; but in 1790 Tallleyrand woke the whole thing up, and set up a committee with the specific objective of developing a decimal system:-

1790. Talleyrand (then Bishop of Autun) submitted to the National Assembly a proposal to standardize the length of the seconds pendulum at 45° latitude. His proposal, having been referred to the Committee on Agriculture and Commerce, was recommended to the king, who sanctioned action on 22nd August. The French Academy of Sciences was made responsible, and appointed a committee that included Lagrange and Laplace among its members: their first report, in October, recommended the decimal division of money, weights, and measures.

To his credit, Talleyrand did attempt to open discussions with Britain; but he wrote not to the prime minister but to an individual MP of his acquaintance; and nothing came of it. In due course the committee issued its report, and (crucially) it stuck to the principle of basing the new unit not on any unit then in use, but on a fraction of the length of part of a meridian of longitude (as far as that distance could be established at that time):-

"Second report by the committee recommending that the standard of length should be:
One ten-millionth of the meridian quadrant.

"This length was to be determined by calculations based on the measurement of a meridian arc extending from Dunkirk to Barcelona; that is an extension of the line measured by Lacaille and Cassini in 1739. The decimal aspect of the system, recommended in their first report, was emphasized by discarding the traditional degrees and minutes of angular measurement. The committee rejected the pendulum, on principle, because it involved time as a non-linear element. The Academy of Sciences adopted the committee's recommendations."


I have no idea why Dunkirk and Barcelona were chosen to be honoured in that way!  

Very soon after that, of course, the French got started on having their Revolution, executing the king etc. - but the committee went on meeting. And it was at that time that they abandoned the 'toise' (the fathom, six imperial feet) and proposed the more or less arbitrary metre instead. It seems relevant that that was the year in which they found themselves at war with Britain, so there was never any question of joint action after that:-

"1793. Louis XVI executed, on 21 January. Third report of the committee; recommending the name "metre" for the new linear unit, and giving its length provisionally as 443·44 lines. This provisional length was calculated from Lacaille's measurement; which showed the length of the meridian degree at latitude 45° to be 57027 toises.

"Meridian quadrant = 57027 X 90 = 5132430 toises= 5132430 x 864 = 443·44 X 107 lines

"The Academy submitted its committee Is report to the Convention, which had replaced the National Assembly: this report was adopted by decree on 1st August, and a brass standard of the provisional metre was made: it is preserved in the Conservatoire des Arts et Métiers at Paris.

"War with England began in this year."


Interestingly, the new system appears to have been pretty unpopular, even in France itself, for many years after that. That continuing problem was not 'resolved' until 1837, when use of any other system of measurement was made a criminal offence:-

"1837. The decree of 1812 was repealed, and it was enacted that the use of measures and weights other than those of the metric system would become a penal offence from the beginning of 1840.'

Full account of all the goings-on, which persisted for the best part of a century, here. Hope it's of interest:-

http://www.dozenalsociety.org.uk/metrix/chronology.html

[Edited 2012-09-26 22:12:08]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 147, posted (1 year 6 months 3 weeks 2 days 16 hours ago) and read 3138 times:

Quoting NAV20 (Reply 146):
Turns out that I may have been a bit unfair on those mathematicians! Their activities weren't the whole story.

Always good to find facts.

Quoting NAV20 (Reply 146):
Interestingly, the new system appears to have been pretty unpopular, even in France itself, for many years after that.

What do you find interestingly about that? I find it natural. Most humans resist change no matter what. I have been involved in changing many ERP systems. Without fail there are many complaints about the old system leading up to the change but as soon as the possibility of change is there the old system is suddenly the best and the new should be made to work exactly like the old.

The reality is that the Imperal system(s) is completely impractical with math as we know it. That is why you may see the same distance expressed as 1,000 ft or as 300 yd. In metric it is always the same no matter if it is expressed as 300 m or 0.3 km.

The next problem with Imperial is when you introduce precission. You need to introduce a completely different type of measurement. The Washington monoment is 555 ft 5 1/8 in. There are 3 different pieces of information whereas in metric you go straight to the math you know and express it as 169.294 m. To enter and maintain the imperial distance in Excel you need 4 cells. With metric just one.

If you ever done programming you will know how much extra work it is to handle imperial distances. Either you need to force everyone to use a single unit even when that isn't typically the unit used or you need to do several steps to handle input of data. Then you need to convert it to inches to so that you keep your database efficient. Finally you need to convert it back to when you display it again.

It s not without reason that almost all the world has changed to metric even though individuals resist the change. Between the inconsitency in the system and the inconsistency in what the units represented it really became too impractical in a society where people interact outside of their local area.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 148, posted (1 year 6 months 3 weeks 2 days 13 hours ago) and read 3110 times:

Quoting cmf (Reply 147):
The reality is that the Imperal system(s) is completely impractical with math as we know it. That is why you may see the same distance expressed as 1,000 ft or as 300 yd.

'Please explain,' cmf? To my certain knowledge, 300 yards have been 900 feet for at least the last thousand years?



"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlinecmf From , joined Dec 1969, posts, RR:
Reply 149, posted (1 year 6 months 3 weeks 2 days 10 hours ago) and read 3092 times:

Quoting NAV20 (Reply 148):
'Please explain,' cmf? To my certain knowledge, 300 yards have been 900 feet for at least the last thousand years?

When you guesstimate a distance, when was the last time you sugested it was 333 1/3 yard?

Simply put. If you use yards you round to 100's (if long enough) and if you use foot you also round to 100's or even 1,000's.


User currently offlineMD11Engineer From Germany, joined Oct 2003, 13797 posts, RR: 63
Reply 150, posted (1 year 6 months 3 weeks 2 days 8 hours ago) and read 3065 times:

Quoting NAV20 (Reply 146):
Very soon after that, of course, the French got started on having their Revolution, executing the king etc. - but the committee went on meeting. And it was at that time that they abandoned the 'toise' (the fathom, six imperial feet) and proposed the more or less arbitrary metre instead. It seems relevant that that was the year in which they found themselves at war with Britain, so there was never any question of joint action after that:-

Actually the idea was to use a natural constant as the base of a new decimal measuring system instead of arbitrary non connected dimensions. At this time the sciensts used the circumfence of earth as the base of their measurements. They divided the quarter circle of a meridian (assuming earth to be a perfect sphere) into 100 units, which makes the whole circle 400 units (my late father´s geologist compass is divided into 400 metric degress). Then, similar to the nautical mile being the distance of one arc minute on the surface of the earth, the earth circumfence (again assumed that earth is a perfect sphere) equals 21600 NM, the meter assumes that the length of the earth circumfence 10000 x 400) is about 40000 km.
To get the length of a meridian they had to measure the angle between two points where the distance was known via astronomical means. Dunkirk and Barcelona were far enough aprt for reasonable accuracy and the distance was easily measurable by French scientists.
This calculated result was cast into a platinum-irisium alloy bar as the standard metre.
Later scientists discovered that earth is NOT a perfect sphere, so they tried to find other, more constant and accurate means to define the mtre, this is why today the metre is defined via the speed of light and interference.

Jan


User currently offlinewingscrubber From UK - England, joined Sep 2001, 845 posts, RR: 0
Reply 151, posted (1 year 6 months 3 weeks 2 days 7 hours ago) and read 3052 times:

Water is also a useful reference point for the metric system, where 1 cubic metre of water = 1000 litres, weighing 1000kg, so 1L of water = 1kg. The celsius system of temperature was also originally based on 100th increments between freezing point and boiling point.

Problem is these references only apply in normal atmospheric conditions on Earth, pressure influences boiling point and density, so the reference points move under certain conditions.



Resident TechOps Troll
User currently offlineMD11Engineer From Germany, joined Oct 2003, 13797 posts, RR: 63
Reply 152, posted (1 year 6 months 3 weeks 2 days 7 hours ago) and read 3048 times:

Quoting wingscrubber (Reply 151):
Problem is these references only apply in normal atmospheric conditions on Earth, pressure influences boiling point and density, so the reference points move under certain conditions.

Thus the move from eartn planet based reference points to basic physical constants.

In normal ife you don´t need that exact defintions (e.g. in machining you go down to 1/1000 of a millimetre, builders use a tolerance of a centimetre ect.), but some scientifical or high tech branches (e.g. nano technology) need to be more exact and reproduceable.

Jan


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 153, posted (1 year 6 months 3 weeks 1 day 23 hours ago) and read 3014 times: