Measuring units and stuff

[Jerboy]

The United States is one of a very few countries still using a proprietary measurement system. While I don't like it, I think it will be this way for a long time. The pecularity that's been around in the last decade or two is mixed units. Why do so many people use mixed units? I think it's really stupid. People in Europe and Asia are not innocent either.

TV's diagonal size is internationally expressed in inches

Golf is internationally expressed in yards

Tire units are internationally mixed P195/60R15 195=width in mm, 60=section height is 60% the width, R=radial, 15=15INCHES wheel diameter

then engine specs:

3.0L V6, 210hp and 250ft-lbs of torque... Wouldn't it make more sense to say either:

183CID, 210hp, and 250ft-lbs torque. In the 70's , auto manufacture's exclusively used CID's. If they choose to switch displacement to metric, they should change all specs to metric or simply stay where they were before using CID's.
or

3.0L, 157kW(213ps), 340N-m(34.6kg-m)
?


Somebody explain why people insist on randomly mixing up units. Each unit has it's advantage, but I don't understand why they feel it's necessary to blatently stir them together.

 

[jasonroehm]

I'd say that it's just the fact that people are against change. I mean, America was supposed to go to the metric system a long time ago, but I still see our road signs numbered in miles. The units you were talking about have just become so standard that people expect to hear statistics in those units. Also, since people are so used to these units, they probably don't want to mess around with conversion factors to get them in all metric units. There's just enough of us stubborn Americans out there to keep the world from completely standardizing on one unit system.

Now that I think about it, that's why EE is the best of the disciplines. When was the last time you needed to look up a conversion factor to convert a volt or ampere to another unit? It doesn't happen! EE's have their act straight, now the rest of the world needs to catch up.

 

[CurtOien]

We resist change because we are lazy in the short term even when we know another system is better in the long term.
How many of you are using Dvorak keyboards?

 

[figgypower]

I've always heard of the Dvorak keyboard and its many benefits, but I've seldom seen one to actually buy. I would buy it in a heart beat if I
knew where to buy one.

I remember having lots of class discussions and discussions with friends about the measuring units, and how we felt the metric system was
superior. Why? It's just a lot easier to deal with; for example, conversion to meter to kilometer is a lot easier then feet to miles. Why don't
businesses (who, it can be argued, truly rule the world) just switch to the metric system? It'll result in cost savings in the long run due to
simplicity and ease. As far as mixing the units, I've always been told that most of the world is somewhat standardized on the metric system.
Then the U.S. yield its influence and that's why we have wierd mixed up units.

 

[RSMemphis]

Actually, what you say is not really true anymore...

TVs and monitors HAVE to bear the measurements in cm, inches are optional (took a while, but this is done these days)
Cars are measured in kW and Nm as mentioned. (Although horsepowers are still ghosting around).
Tires - well, that one is still done. I have no idea why.

Windows in Europe even tells you that you have no disk in the 8.89 cm drive (or was it 8.9 cm drive, I don't remember)

LOL

 

[Jerboy]

<< We resist change because we are lazy in the short term even when we know another system is better in the long term.
How many of you are using Dvorak keyboards? >>




Although, we aren't resisting change. We decided to do a half-ass unit changing instead of not changing at all or change it entirely.

 

[Menelaos]

RSMemphis

Have yet to see that Windows version, and AFAIK I still live in Europe (Belgium).

Menel.

 

[rgwalt]

The metric system is definitely easier to deal with in calculations and conversions. However, the simple fact that we have an infrastructure based on the english system means we continue to use it. The problem is that very few Americans have a true concept of what a metric unit represents. I know what a pound feels like and what a yard looks like. I don't know how to guess how much a centimeter is, or a kilometer. Heck, many cities are laid out with 8 city blocks to a mile. Also, how tough is it to look at a bolt and guess the size in english units? Someone who works with cars a lot is able to do that. On the other hand, that same person would have trouble guessing the size of a metric bolt.

When I did my senior design projects, I asked my teacher if I could do the calculations in SI. He laughed and said no, because the chemical industry in the US is almost exclusively on the english unit system. New plants are designed to interface with existing plants to share steam, cooling water, etc. Thus, the new divisions are designed using the english system so the operators don't have to switch between unit systems on the fly... "Should the cooling water flow rate be 50 gallons per minute, or cubic meters per minute?" A wrong answer to that question could lead to a catastrophy.

I remember being in middle school and grumbling whenever we had to do calculations in the metric system. Once I reached highschool chemistry and physics, I grumbled when I had to use the english system.

Ryan

 

[bizmark]

I think it's just a matter of familiarity and, to some extent, ease.

With a person's height, for example, in U.S. units it can be expressed easily as two numbers: feet and inches. 5 foot 8. Sure sometimes you have 5 foot 11, which is 3 digits, but still, it's easy to say. An inch is an effective resolution for measuring a person's height, IMO. Differences within an inch of each other aren't particularly meaningful and could have a lot to do with a person's shoes or whether they just woke up. With centimeters, you typically have three digits, e.g. 185cm or something, and I think that 5cm would be the most desired resolution, even though it loses something when compared to inches. Even if you round to the nearest 10, you still have the 0 floating around taking up space. 6 foot. 6 foot 1. Compare that to 183cm and 185cm. The same data is expressed more compactly.

Basically, I think that the meter is too big and the centimeter and decimeter too small. I think that the foot is simply a more "useful" unit of measurement. How many things are usefully measured in integer amounts of meters? What about centimeters? You can look at something and easily say that it's 1 foot long, but saying that it's 30 cm implies a precision that you don't have. When you say one foot, it's sort of implied that it's one foot plus or minus an inch or so -- the next smallest unit. When you say 30cm, plus or minus what -- 5 cm? You're not likely to be that far off. But most people certainly can't estimate within 1cm for lengths of about 30cm. So then do we always assume +/- 10%? I guess that would work. Maybe that's what people do in metric-denominated countries?

I think that the inch parameter for wheel-sizes is a perfect example of this. An inch is about the right resolution for wheels. Want to make them come in 2.5cm increments? Okay, well, I guess you can. But 5cm would be too big of a gap between sizes, and 1cm or even 2cm would be too small. Granted, the fact that we have the depth/width of tires measured in CM is pretty odd when they're juxtaposed with the inch measurement of wheels.

With liters and gallons the argument doesn't go nearly so well. It helps a lot that a liter is very close in size to a pint. We're all very comfortable talking about 2-liter bottles of Coke. But the shape of bottles easily fools you. Ask anyone how big a 2-liter bottle is compared to a gallon milk bottle, and I guarantee you that they won't tell you that the two-liter is about half as big as the gallon. Volumes are a lot more difficult to estimate than lengths because of this shape factor. Or I guess actually we typically don't measure lengths for things that aren't straight

But I think we can see the switch to liters for measuring engine displacement as a support for my argument of "usefulness". No engine is a gallon, so we've always gone with cubic inches, which typically number in the hundreds. Liters express things as an integer and, at most, a single decimal. We go from two numbers to three. We lose a bit of resolution, but for most purposes two significant digits are more than enough for most people.

With the golf thing, it is pretty weird that it's always in yards. I didn't know that. I guess that in Japan the pitcher's mound is still 66ft from the plate and the bases are 90ft apart? Maybe we can make an exception for sports.

Anyway, it's pretty clear that my argument is very weak and based on intangible factors, but I think that most Americans, who have lived with the U.S. system all their lives and who have not had any substantial contact with metric units, would agree with me. The U.S. system just makes more sense somehow. Granted, it would make no sense if we didn't grow up with it. But still, once you're used to something, it's very difficult to throw it away.

 

[wnstitw]

does anyone remember that mars mission 1-2 yrs (the last one)? well from what i hear the reason for its failure was a mix-up in units. someone mistook meters for feet, or something like that.
just goes to show how disastrous the mixing of the two measuring systems can be. very unfortunate, particularly in this case since the space programs are not enjoying much positive attention in the past few years.