I didn't know there was such a thing as metric time, Jon. Upon checking it out, I found there is such as thing as metric time based on seconds, with terms such as kiloseconds and milliseconds: http://en.wikipedia.org/wiki/Metric_time
It was 32 degrees in the shade here today. Don't any of you give me the temperature at your place in farenheit. There isn't even a simple conversion factor. Have you noticed that datasheets give product dimensions in mm and archaic inches, but operating temperature only in Celcius ? Some things will always be measured in inches - here water pipes are always specified in inches, for some reason. Yes, you look silly with your pounds and gallons. Did anyone mention the Boeing 767 which ran out of fuel mid-fight because it had been fuelled using the wrong units?
Hi, Ann. Same here--two sets of wrenches and also two sets of Allen wrenches. Thank goodness we can still still use slotted and Phillips-head screwdrivers in metric and English fasteners. Except in Canada where they love the square Robertson-head-drive screws. Nationalism, I guess. Robertson was a Canadian. Wikipedia has a good list of screw drives: http://en.wikipedia.org/wiki/List_of_screw_drives.
The French tried metric time after the revolution, but it never caught on. I don't think anyone said we had to use base-10 for everything. I use hexadecimal almost every day for programming and it makes bits and bytes easy to decipher. And I use octal and binary. That said, an early manual for the 8008 microprocessor did list op codes as decimal numbers. That changed quickly.
It has always seemed to me that a large impediment to "learning" the metric system has been an obsession with mathematical perfection: we try to teach that a millimeter is .039370078 of an inch, and everyone glazes over. At the same time, nobody knows EXACTLY what an inch is, we're comfortable with it because we know close enough for our purposes.
I think it would make it easier if we could either learn metric units independently, without reference back to imperial units, or else relate them in easy-to-remember general terms that are good enough for practical purposes: an inch is about 25mm, a gallon is about 4 liters, a mile is about 1.6 km... people whose tasks require more precise knowledge will acquire it in any case.
As for manufacturers converting over, there is cost involved: we have existing stocks of US fasteners that can be hard to distinguish if accidentally mixed with similar metric ones, we have shorthand default tolerance systems on our prints that are based on the units being expressed in inches, we have standardized material stocks in inch increments. The structural difference between a piece of inch-size steel tubing and its closest standard metric neighbor can be very significant and require substantial redesign of the product that uses it. The cost of the change may not be great, but in business everything comes down to cost vs benefit: if 99% of your customers are in the USA (the size of the US market and the physical size of the country make this fairly common, unlike many other countries whose manufacturers can hardly operate without exporting) and are either neutral or prefer the US system, a business may not see enough benefit in the conversion to cover its cost.
The change will come ... but we've been saying this for over a century now (the US first recognized the metric system legally in 1866), and it hasn't come yet.
I apologise, I looked back only to my second post.
As for time, the second is a metric standard, and minutes and hours are non-standard. However the "day" is non-exact, and there is currently a big issue with increasing numbers of leap-seconds, which cause systems like GPS some pain. The "year" is even less exact, with leap-yeaars every four years except for exact centuries but not when it is divisible by 1000 ... so 2000 was an exception.
Seconds are just fine, because the significant human-convenient time divisions are non-integral, and decimal doesn't work.
Actually, you did say the two countries were backwards. Judgemental and inflamatory remarks are not really helpful to the discussion.
I'll re-phrase one of my points: "The hand that rocks the cradle" : teach only metric and a decade or so later, you'll have only metric.
BTW - since metric is so supior, it's time for "metric time" (10 hours a day, 10 days a week, 10 weeks a month, 10 months a year). Oh yeah, maybe metric isn't always "clearly" superior when physical constants are involved !
I used to relatively apathetic on this matter. Up until about a few months ago, it wouldn't have bothered me if we continued to primarily use imperial, but a switch to metric would make all those units learned in science classes all the more relevant.
Now that I see this:
In an article, 'The Case for U.S. Metric Conversion Now' (1992, December 9) Richard P. Phelps stated that:
'It (USA education system) teaches two systems of measurement in the schools and, the confusion from learning two systems aside, there is a cost to the time spent in teaching two systems. A full year of mathematics instruction is lost to the duplication of effort.'
We use a full year of instruction to teach two systems of measurement. That's a year that could be used to teach an entire subject. Most importantly, it's a year that could be used alleviate a widening gap between US students and their international counterparts, most of whom only have to worry about one system of measurement.
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