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Lol, as a non-american, I find this skill badge rather amusing
 
+Yuan Gao as a Canadian living in the US, it's infuriating. As I like to say, "The Imperial system is so played out even the Empire doesn't use it anymore."
 
+Viet-Tam Luu heh, well, unfortunately that's not entirely true, roads are still measured in miles here in the UK.  Also oddly I design electronics in inches, not entirely sure why. I blame 0.1" pitch components.
Ho Liu
 
There's nothing wrong with either system, it's just like using a different language.
 
+Ho Liu It's not that there's something wrong with imperial units, rather there is something very right with metric units.  Let me give you an example: My 1.6 ton car has wheels of rolling radius of 12 inches, if my car can produce at the wheels 360 foot-pounds of torque, how long does it take to accelerate to 60 miles per hour considering F=ma only?

Fairly straightforward mechanics question, rearranging the equations give t=V*m*r/T, so now tell me what 60mph * 1.6tons * 14inches / 360lbs/ft equals?
 
I think you need to convert the tons in to slugs don't you?
 
I always start with a much simpler question: How many ounces are in a gallon? They start mumbling about ounces in a pint or a quart, quarts in a gallon... The big failure of metric in this country was the constant talk of conversions. When you are using one system, there are no conversions; you don't need to know how many mL are in a quart. The recipe says 200mL, so you measure 200mL.
 
+Kent Durvin  A quart's about a litre.  And I was always taught that the l for litre is in lower case to avoid confusion (L is the EE's symbol for inductance.)
Ho Liu
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+Yuan Gao if you were to do that sum in metric, you would still need to convert the weights in to kg the distances into m.

Also both methods use time in seconds. How is it time doesn't need to be decimalised like the rest of the metric system.
 
+Ho Liu You've missed the point, to do the calculation in imperial you'd have to apply conversion factors of 5280 feet per mile, 2000 lbs per ton, and 0.083333... feet per inch to get all the units to a point where you can actually perform the calculation.  Whereas the same calculation involving metric units of km/h, tonnes, mm and Nm, you just do the calculation and then you can instantly see that km and mm cancel out in terms of scale when working in metres; and tonnes is a thousand times bigger than SI kg, and Nm is already SI; but true you do need to throw in a conversion between seconds and hours too, but not having to deal with all the other weird conversion factors speeds up the calculation greatly.
 
What's with 1000 Milli secs in a second then 60 secs in a min ,60 mins in an hour,24 hours a day,365 days in a year ,then back to a nice round decades centuries and millennia??
 
There is a unit for fractions of a second. It is called a third, as in third division of an hour. There are 60 thirds in a second. 
Ho Liu
 
+Yuan Gao maybe you are missing my point.

All I'm saying is just because the conversion factor isn't a factor of 10 doesn't make it any different. You still need to convert your units.

Your example with the cancelling out doesn't apply to me as I am useless without a calculator/computer. I would still convert every unit before starting the calculation.

If you frequently use imperial units, you know what the conversion factors are.
 
+Ho Liu Ok, I agree that you'd convert every unit before calculation, but are you saying that it's just as easy to multiply by 1/12 or 5280 than it is to multiply by 10, 100 or 1000?

For example if I needed to calculate something involving 34mm in SI units, I will often just punch in 0.034 into a calculator without thinking about it.  Or 94.5kW I'll just punch in 94500.

If you frequently use imperial units, you may know what the conversion factors are, but you're still going to have to expend some time multiplying out these factors; but if you frequently use metric units, you can just shift decimal points around without doing any calculation.

If you're used to doing imperial unit conversions, then I'm not saying you should switch here and now, but the most important point here is very much related to the original post from +Adafruit Industries (and here I am playing the "think of the children!" card): if there is this great new metric system in the world that is internationally accepted and endorsed by the global scientific community, easier to learn, less illogical than imperial units, and doesn't require memorising conversions, why then would you teach your kids only imperial units?

Put it in your analogy: if you were a non-English speaker, why would you teach your kids only Latin instead of English?  They're both languages sure, but one of them is used internationally, and the other has unnecessary (considered today compared to most modern languages) verb conjugations to memorise, that is only really useful in certain places.  (Truth be told, English isn't the most logical of languages either).
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