Do you use Imperial or Metric? - Page 9

On December 09 2011 16:27 Zephirdd wrote:
I find it hilarious that you call "Standard" the one system that is not standard around the world.

Seriously, whats with that. Metric system is the standard everywhere but the US and a few select countries out there.


To be honest, I wonder WHY hasn't the US switched to metric yet. It's intuitive and simple, feets/inches/yards just don't make sense IMO, but I guess that's about how used you are about it heh.

I understand the use of Farenheit although I think using a 0-100 scale in relation to water is simpler. However, the feet/inches/yards just don't make sense at all for someone who wasn't born with it. Same thing with pounds in relation to kilograms.

Yeah, 100% metric/kilo system for me.

On December 09 2011 13:43 Keyboard Warrior wrote:

please tell me where i can buy 0.3x0.3x3.6 meter wood

On December 09 2011 13:43 Keyboard Warrior wrote:

please tell me where i can buy 0.3x0.3x3.6 meter wood

On December 09 2011 16:33 Velr wrote:



Ahm.. A store that sells such wood? What else would you buy and how else would oyu name it? WTF?

To this day i haven't managed to memorise how much an Inch/Feet/Yard is.

On December 09 2011 15:16 Elysian wrote:
One of my friends was discussing this with me before. "Standard" (imperial) is actually a very convenient notation to use in civil engineering. Basically, metric gives you precision and easy scales but at intervals that aren't very useful in a practical sense (e.g. day to day). While both metric and imperial can be broken into fractions, everyday measurements usually are usually *small* whole numbers when done in imperial as opposed to metric.

A few other examples:

Long Distances:
There aren't many times when you use say "go 700 feet that way" or "after 200 meters turn right". If you're in the city, you usually say go X number of blocks. If you're travelling farther distances, you'll want to use kilometers or miles. I think we can all agree that miles and kilometers are about equally useful in that respect.

Short Distances:
If you are trying to point something out to someone in the same room, I don't know what the "standard" increment of measurement is in metric (10 cm?) but increments of a half foot are quite easy to work with and scale well (it's easier to triple 2.5 feet than it is to triple 75 centimeters).

Building material sizes:
Most metal sizes (e.g. rebar, welding, metal sheets) can have precision to 1/8". The equivalent to that in metric is 3.175mm. While you could say "yeah but they could have just made metal in increments of 3mm", imperial has benefits when you start looking at areas and moments of inertia.
Rebar #'s are done in 1/8 of an inch increments; so a #4 rebar has a diameter of 4/8 or 1/2 an inch, #8 rebar has a diameter of 1 inch, #9 has a diameter of 9/8 of an inch. The corresponding mm's are 12.7, 25.4, and 28.65 (you don't use cm that often since stress is often measured in megapascals, N/mm^2). The areas of these rebars are: .2in^2, .44 in^2, and 1 in^2 or 129mm^2, 509mm^2, and 645mm^2; imperial here is much easier to spot check.

Moments of Inertia:
In order to calculate how much a beam will deflect (we have to control deflection in order for people to feel comfortable in a building), you need to use moments of inertia. Moments of inertia have units of length^4. I'm not sure if these are usually done in cm or mm (since no stress is involved) but in either case the metric value comes out to be substantially larger than the standard value. In the case of mm, 78 in^4 becomes 32,466,051 mm^4. In tall buildings, those moments of inertia can quickly rise to billions or trillions for the members at the base.

Scale:
Because you (usually) want to stay in the units of stress, you typically stick with inches or mm all the way through your calculations. You may say, 32466051 mm^4 is no problem, just use .3246 cm^4, but then you have to be very careful whenever you are using powers (for example, in concrete analysis you usually use square roots) since 10mm^(0.5) will not give you the same value as 1cm^(0.5).
Although the inches to feet conversion might sound quite stupid, it offers a check to make sure you haven't forgotten to convert units anywhere since the number itself actually changes (in metric only the magnitude would change).


Anyways, I think that these are a few of the reasons why it has stayed in use for so long. From a science standpoint, I agree that metric would be more useful since it offers scale and a high degree of precision. From an engineering standpoint, however, inches and feet do have their uses.

On December 09 2011 16:41 airen wrote:
Metric ofc.

About the math base. I've always found it so incredibly weird that it's called "the 10-base system". Even the scientific world does this. The thing is that every single base (except unary) has a "number 10", and it refers to different values in everyone of them! It would make much more sense to call it "base 9+1" (as in, last defined digit + 1), in the same way it would make more sense to call base 8 "base 7+1" since the digit 8 doesn't appear in base 8 anyway.

Personally I would prefer base 16 over both 12 and 8, but that's just me.

Advantages of Standard
1. Standard goes more naturally with fractions - quarter of a pint, half foot, etc. Technically, you don't say half meter but rather 50 centimeters or 500 millimeters.

2. Standard units are more practical and convenient. No one goes to the grocery to buy 400ml drink, instead, they buy it in 12 ounces. No one buys 5 meters of wood, instead, they buy it is 1x1x12, all in feet.

On December 09 2011 15:55 Mista_Masta wrote:
The base 10 system simply means that in a number, every digit represents a different power of 10. For example, the number 471 means 4 times 100 (10 squared), 7 times 10, 1 times 1 (which is 10 to the power 0). If you were to take a system with only 8 digits (0,...,7) then each digit would represent a different power of 8. So writing down 471 would mean 4 times 64 (8 squared), 7 times 8, 1 times 1. (In 10 digits this evaluates to 256+56+1 = 313) Now if we were to multiply this by 8 (still in our 8 digit system), we would have 4 times 8 cubed, 7 times 8 squared, 1 times 8 and 0 times 1, which is 4710. As you can see, we simply added a zero to the end, just like we would have when multiplying by 10 in a 10-digit system. I hope this clarifies the calculations in different systems somewhat

On December 09 2011 15:37 emythrel wrote:


The babylonians used a base 12 system, our clocks run on a base 12 system too. The decimal system is used mainly because its easier to do mathematics using a decimal system and since the entire modern would is founded upon maths done with this system... changing it might be tricky. We could go to using binary, but our brains don't cope as well with it as a computer lol.

In the UK, at least when i was a child, we did height and weight in imperial and most other things in metric. However we still measure distance on a road in miles and speed in a car in mph.

p.s try representing 7x4 in a base 12 system....... its not so easy as = 28 ... in fact in base 12 it would be 24. That just confuses me more!

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On December 09 2011 16:45 lachy89 wrote:
I think the most interesting and somewhat ridiculous part of the thread is the fact that some people cannot fathom how you can possible go to a store and buy 90 x 45 Timber or a Liter of milk or any other products using the metric system.

The initial poster even states that the "standard" system is beneficial due to this reason, which is 100% incorrect.



Both 1 and 2 are completely incorrect. In terms of 1 The only reason I can think of that you can make this claim is that you are forced to use half a mile as you have no idea what half a mile converts to (880 yards wtf?).

2 Is wrong and your delusion is only present as you are brought up buying everything in amounts due to what is sold. I buy 600mL cokes all the time and I am used to it. I work for a construction company as an engineer and our lengths of reinforcement bought are 3m 6m and 9m (most of the time). So once again 2 only applies because it is what you are used to and what is offered in your country.

There are no benefits of the "standard" system.

On December 09 2011 16:40 Robinsa wrote:


Im not sure if youre serious or not with this post doesnt provide any argument at for the imperial system at all. All the standards you talk of are American standards based on you system. It most likely would have been 3mm and not 3.175mm if it was a number set from a metric standard and not 1/8". Take the 9mm bullet for example. Its a German standard so its easy to work with in the metric system but its 0.355 inches. The difference is however that I know that 3,175 mm is 0,315 cm without having to do any real math. Could you do the same conversion with 0.355 inch into feet that fast? The argument that theyre hard to convert is simply not true. It probably has to do with you not being used to it. As for the short distances "its easier to multiply" etc. I dont really see one being harder than the other unless youre trying to convert it into some other unit in which case metric is superior.

78 in^4 becomes 32,466,051 mm^4. In tall buildings, those moments of inertia can quickly rise to billions or trillions for the members at the base.

On December 09 2011 16:57 Velr wrote:


Is no one using decilitres and centilitres? (.1 and .01 of a litre)?

It's common here?