desconhecido 

[QUOTE=cyccommute;20407639]Yeah, you got me.


No, I don't know that it's highly offensive to women. Women, and young women, can be scientists and engineers just like men and there appears to be no natural impediment and there should be no social impediment. I neither said nor implied anything to the contrary.


To recognize that hour is not a metric unit and that it is not derived from SI is not to imply that km/h is not a useful unit nor is it to imply that we should only use m/s for speed and velocity

As for your unnecessary pedogogy about precision, You are correct that it has to do with context. If you go down to the meat market and order two pounds of ground beef, do you say, "I'd like two point zero pounds of ground beef"? If you order "two pounds of ground beef" do you find it acceptable if you receive 1.6# of ground beef? If you call up a headset salesman and order a 1" headset, do you believe that it's the same as ordering a 3 cm headset? Will it be acceptable to receive a 1 1/8" headset? Well, you know the answer to all those questions. Just like you know the precision that is implied when someone says that 1" is equal to 2.54 cm or when someone says that 3.6 km/h is the same as 1 m/sec. Why you desired to lead us down this trivial and silly path, only you can answer. For following, all I can do is apologize.

tagaproject6

But how many knots are you averaging?

Happy Feet

This point is not lost on me and why I have no problem thinking of kph as a defacto metric measurement.

The problem is that when viewed from a scientific POV it may not fall into what scientifically might be considered a strictly metric definition but road speeds are not intended to be used for scientific purposes by scientists. They are ball park limits (usually in gradations of 5-10) set for the average man using gross measuring instruments like wrist watches and speedometers.. From that POV kph is a metric measure. Arguing otherwise is falling into the trap of using one set of definitions to define something in a realm where those parameters don't apply. Like arguing for the use of proper grammar and punctuation in text messages sent by smart phones.

cyccommute 

[QUOTE=desconhecido;20407678]You completely missed my point. You are the one who castigated everyone for not being extremely precise about usage of the "metric" system. Yes, the hour is not part of the metric system but it is still a useful unit of measure. But if you are going to be pedantic about people using kilometers per hour and calling it a violation of the metric system, then why aren't you equally pedantic about the precision of measurements? It wasn't the 29.33 feet that was the problem, it was the "about". That level of precision is not called for unless you stipulate what it is that you are attempting to measure.

Look at it this way: If 20 mi./h is "about" 29.33 feet/sec what is "exactly" 20 mi./h? 29.333 feet/sec? 29.3333 feet/sec? If I were to call up someone and ask for a 1" headset, I would expect a certain level of precision to be involved and implied. A measurement out to at least a couple of decimal places is implied because of the fit. But if I were to call up the "headset salesman" and ask for a headset that is about 1 inch, I shouldn't be surprised if I received something entirely different from what I was expecting. Again, "about" is the problem.

Finally, I'm going to go back and address your comment about this being "junior high physics". First, I don't know of anywhere that teaches physics in junior high. Physics when I was a kid back in the Pleistocene was a high school level class. Second, I wasn't taught significant figures until I reached college level chemistry and even then it was a fairly difficult concept to grasp. I see a lot of highly educated engineers and chemists who struggle with it.

cyccommute 

As a scientist, I don't always follow the rules laid out by the various societies that have attempted to bring some order to the chaos. In a published paper, I will usually use the proper units but not always. Pressure is one of the ones that I see most commonly. Most people will use PSI in common conversation and even day to day because that is what they are used to working with. They have a "feel" for what 100 PSI, for example, seems like. Much like the second, there are just too many pascals (689,000) in 100 PSI to think about.

Chemical names are another issue. 2-Methoxyphenol tells me everything I need to know about the compound guaiacol and it is easier to spell but people still use guaiacol even 40 years after I first ran across it because people know what guaiacol is but they have to think about what 2-methoxyphenol is.

jefnvk

Well that was a helluva thing to quote and call me back here for

jgwilliams

I, too, was in school when we started switching to metric so I'm pretty comfortable with either. I don't what Canadian currency was like but I'll bet you didn't have to cope with a stupid system where there were 12 pennies in a shilling, 20 shillings in a pound or 21 shillings in a guinea. And then the stupid UK government decided they didn't want to bid farewell to their precious Pound Sterling so the new system also used pennies and pounds, changing the symbol for penny from 'd' to 'p' so we all went around referring to the new penny as 'pee' to distinguish it from the old penny. So if visitors to England wonder why we refer to, eg, '50 pee' rather than '50 pence' that's the reason. It still annoys me 48 years on.

Of course, we didn't make a nice clean break with Imperial either, so our road signs still have miles marked on them and while the weight of almost everything is now in kg we still tend to refer to our personal weight in stones and pounds - a stone is 14 pounds for those who aren't familiar with this ridiculous system, and there are 8 stone or 112 pounds to a hundredweight and 20 hundredweight, or 2,240 pounds, to a ton. But that's so confusing that we also have a short hundredweight which actually is 100 pounds, leading to a short ton of 2,000 pounds. And the problem with that is that a long ton is actually very close in weight to a metric tonne. I also grew up with Fahrenheit but was very happy to abandon that utterly bonkers system.

ZHVelo

The same you'd wear in the 50-77 Fahrenheit range?

Phil_gretz

Interestingly, many of us have SAE wrench sets from back in the day, working on our American muscle cars. Now, those wrenches are relegated to plumbing duty only. If you do a lot of plumbing work, you find inch measurements. But you don't find much lead pipe.

Gunsmithing finds as many SAE small fasteners as metric, maybe slightly more.

In automotive work, you still find torque values are equally likely in foot- or inch-pounds as they are in N-m.

Kapusta

Oh, how sweet it would be to only have one set of wrenches and sockets.

JohnDThompson 

AFAIK, Canadian currency has always been decimal based, although they did have oversize pennies for a while. And England's old base-12 currency makes sense when you consider that 12 is evenly divisible by 2, 3, 4, and 6 while 10 is only evenly divisible by 2 and 5. But I can't explain the "guinea."

Full disclosure: I did live in England with my grandparents for a while in the mid-60s, before the change to decimal currency.

You can still find non-metric highway signs is rural areas of Canada as well.

mackgoo

Century ride sounds impressive. In the United States many people can't ride 100 miles, a lot of them can ride 62 miles, hence the "metric" century. Century is still in the title, still sound impressive.

downtube42

I've not seen anyone mention this, though admittedly I stopped reading after four pages, that in the 70's the US did begin converting to metric. Km road signs started going up, and gas pumps switched to liters. I was in grade school, and we were taught the metric system, expecting it would become standard. I think it was the gas pumps that made people insane, with those liter numbers flying by so fast they couldn't be read. The conversion suddenly halted, and everything rolled back. Interestingly, there was one 100 km to St. Louis sign on I-70 westbound left standing for probably a decade, reminding me with each passing how my generation was cheated of a superior measurement system.

Kapusta

I was in grade school in the 70s and remember that. Even as a young kid, the switch made total sense to me. The failure of the innitiative was my first glimmer of the the reality that we may have been the most powerful and rich country in the world, but we were clearly not the brightest.

Bah Humbug

I love the metric debate.

The other countries in the world that claim to be metric aren't, at least not in the way people banging on about how America needs to metricize think they are. Let that sink in for a minute. The Brits still use stones for body weight. The Germans use pferdstarke for car engines. HK street vendors sell produce by the pound. South Korea had to illegalize the use of the pyeong as real estate floorspace measurement because people preferred it to sqm. The list goes on.

Traditional units of measurement grew because they were useful sizes for people. Because of the progression from tsp > tbsp > cup > pint > quart > gallon, you never have to use a large number of the unit. People don't like large numbers, or fractions, and would rather drink a pint (hey, the Brits still use that too!) than a half-liter or a 500mL, and only the latter is technically the way it's supposed to be used. Metric's awesome party trick (everything being easily transferred from volume to weight to energy and so forth) is handy for engineering (where matric is the way to go, as with NASA now), but is utterly inconsequential for daily tasks, so people use the system more convenient for the task at hand. Shocking.

America could "go metric" and change literally nothing, and we'd be "metric" like the other countries around the world are "metric" with people living there continuing to use their traditional measurements for many daily tasks. Would that make everyone clamoring for it happy? I doubt it. For some reason, it really grinds their gears that someone in Ohio is baking a pound cake instead of a 450g cake Get over it.

Darth Lefty 

What is that in electron volts?

Darth Lefty 

If you hate metric vs English units, look up how shoe sizes work, that will really upset you.

Buzzkill53120

My preferred units for velocity is furloughs/fortnight.

downtube42

One of the biggest engineering cluster####s I've been involved with was due not to mistakes in applying units of measure, but in repercussions from deeply entrenched immovable views on which units were correct. Different systems used different units, for no technical reason. As the guy responsible for software that had to bridge the gap, I can attest there was substantial cost on to the company. A global company can try to straddle the fence, but it is going to cost real $. Incredibly stupid.

It occurred to me that it's not necessary to be great to beat the competition, just a smidge less stupid.

jefnvk

I rarely touch my SAE tools these days. Pretty much just wood bolts and the interior trim parts of the Corvette, everything else is metric.

Just don't buy an old British motorcycle, or you can add a set of Whitworth tools too!

berner

I had read about that. That seems to me to be poor leadership. In doing work for the government there would normally be detailed specifications and measurement units would be crucial and prominently displayed in an appropriate section of those specs. Big projects are run by administrators who are not always trained working engineers. We see this at Boeing and collapsing bridges for example.

Kapusta

Perhaps poor leadership... but really this was a failure made more likely by a flawed system. To be using two different sets of measuring systems in any field makes this very mistake more likely, while offering zero benefits.

You are correct that not all administrators are engineers. A good process design should take that into account and be robust enough not to let unit mistakes propagate. One critical part of that is having ONE definitive system of measurement. The moment “miles” pops up on any document or spec sheet an alarm needs to ring with red flashing lights, and nothing moves forward until you find out where it came from.

livedarklions

What's the proper unit to measure whether a thread has gone on too long?

Buzzkill53120

When you get this:

livedarklions

Is that a metric dead horse or an imperial?