NASA is taking [criticism] for deciding to use Imperial units in the development of the Constellation program (http://www.newscientist.com/article/dn17350-nasa-criticised-for-sticking-to-imperial-units.html), their project to replace the space shuttle. 'The sticking point is that Ares is a shuttle-derived design — it uses solid rocket boosters whose dimensions and technology are based on those currently strapped to either side of the shuttle's giant liquid fuel tank. And the shuttle's 30-year-old specifications, design drawings and software are rooted in pounds and feet rather than newtons and meters. ... NASA recently calculated that converting the relevant drawings, software and documentation to the "International System" of units (SI) would cost a total of $370 million — almost half the cost of a 2009 shuttle launch, which costs a total of $759 million. "We found the cost of converting to SI would exceed what we can afford," says [NASA spokesman Grey Hautaluoma].'"

You know, a lot of Europeans probably think that U.S. reluctance to embrace the metric system is just another example of our arrogance. But a lot of Americans (like me) are genuinely interested in adopting this system, especially since I have lived in Hong Kong and in China. We even passed a law (http://en.wikipedia.org/wiki/Metric_Conversion_Act) in 1975 trying to mandate it.

The real problem is that it is surprisingly hard to embrace a new system of measurement when one has spent his entire life thinking in different terms. Many Americans still can't picture a kilometer without converting it to a mile first, and still can't picture a centimeter without converting it to inches. The meter is a lot easier because it's pretty analogous to the yard. The brain gets locked into a certain measurement pattern pretty early in life and it's very difficult to get out of it, even though many would happily embrace it. As I have spent years of my life in countries that employ the metric system, I can understand the surprising amount of mental effort to do so.

It's not that Americans are really all that arrogant or stubborn about the imperial system. Americans have actually been trying to embrace the metric system (http://en.wikipedia.org/wiki/Metrication_in_the_United_States) for some time.

One Brit makes some interesting remarks about the SI system:

Unfortunately, not really. All street signs still measure distance in miles, and eighths of miles, and the like, and half the population think that the metric system is (like the euro) just another damn frenchie scheme to undermine our sovereignty. We have a long history of coming up with crazy conspiricies to demonstrate why the imperial system is our God-given right, and why the French would like nothing better than to force their evil organised system of measurement upon us.

Meanwhile, for at least a couple of decades now, kids grow up being taught nothing but metric, and wonder why the grown ups still insist on using imperial, and what on earth a fluid ounce actually is. Cos everyone seems to use it, but I don't think anyone under 25 has actually been taught it.

Embrace it, embrace the dark British Imperial side. Muahahaha!

The real problem is that it is surprisingly hard to embrace a new system of measurement when one has spent his entire life thinking in different terms.

Aside from exposure, that's largely because many Imperial units, particularly of distance and mass, have direct analogs in things humans commonly interact with, which is why we came up with them. It isn't directly obvious but even the more agricultural units like acre are emergent from the amounts of work people can do in our own internal time-sense. This isn't just true of British units, but of many pre-scientific measures in cultures around the world. (computers let us reinvent the problem by having binary and decimal notations of magnitude as they were better applicable for people who should, nominally, have been smart enough to know better: kilo- alternatively meaning 1024 (2^10) and 1000 (10^3), et al, as an interesting corollary for those interested in further reading).

That said the metric system was invented for a reason and, despite being somewhat unintuitive in the "rule of thumb" sense, is extremely practical and in every way better in any serious application, and we're going to have to bite the bullet on it eventually.

I read this article on slashdot yesterday.

I have never thought of it as arrogance or being stubborn on the part of U.S. residents, but that of an economic wall to climb over. Like the article mentioned, to convert the entire heap of Ares technical docs + software over to metric would cost multi-millions of dollars.

Just think of the cost of transforming every single mile marker sign on the U.S. highways. Even if you slapped a sticker over top of each number on the sign we are talking millions, possibly even billions after you pay out the time worked by road crews.

Like Malse said though, its a bullet you will have to eventually bite.

I don't want to see any human expedition to Mars fail in a messed up descent due to a programmer mixing up metric and imperial units in his/her algorithms.


Cheers,

It'll happen, but the barrier isn't just shuttle plans - it's construction plans, maps, every cookbook, American cars, and a whole lot of people rooted in those things and depending on all of those print elements.

It will be funny some day when a kid is reading a classic book, and has to ask their parents what the hell a mile is.

Constellation is years old. My very first shoot ever was one at Goddard talking about how the goal of Constellation is a manned trip to Mars. Its really too late now to even think of switching over something like that, heaven forbid they accidentally miss one value and fuck everything up.

The only way to truly replace the imperial weights and measures with metric will be if they start dual labeling everything (which they have, but I mean without having the metric conversion in tiny lettering) and teaching them in schools side by side for a generation or so. Then, start doing all measures in whole metric units, with the imperial conversion in tiny lettering for those who still need it. After about 20 years, they'd be able to fully switch.

I think its the fact that it is not a quick fix that prevents it from happening.

These are not the droids you are looking for.

I read a book several years ago that mentioned how some of the imperial units correlate to proportions of the circumference of the Earth with greater precision than could have been measured at the time they were conceived.

Well, anyone who has worked in real estate knows the ridiculousness of real estate units when having to convert from feet to yards to rods to acres to lots. And let's not get into the discussion of a US pint vs a British pint.

But, theoretically, Fahrenheit degrees provides better precision in its general presentation of temperature than centigrade degrees.

But, theoretically, Fahrenheit degrees provides better precision in its general presentation of temperature than centigrade degrees.

Not strictly precise in the accuracy sense, but there is a greater degree of numerical precision in the range of temperatures we usually talk about because Fahrenheit whole number steps are smaller. Centigrade is more accurately specified being as the SI definition includes measurements that wouldn't exist for centuries when Fahrenheit or Celsius were alive -- please note Lord Kelvin's assertion in ~1908 that physics was done save for more precise measuring :>

This does reflect my earlier a point a bit though. 0 and 100 F are both temperatures that humans can discretely experience and compare. 100 centigrade is not -- I believe the highest temperature humans can perceive and report in studies is around 140F/50C after which we only know things are very hot.

It would not bother me at all if the switch were made to metric right now. It would utterly freak out my parents though.

I foresee a gradual adoption of it over the next two generations or so. Eventual standardization is desirable from an economic efficiency standpoint.

Well here's a question: why?

I understand a base 10 system may be easier, but we've survived for a few hundred years using our current one. Why shouldn't the world switch to Fahrenheit instead for the accuracy reasoning above? Why not just go ahead and overhaul our current calendar system to replace its inaccuracies (for example, there's more than 24 hours in a day / 365 days in a year)?

There's plenty of reasoning to switch from one system to another, but at such a dramatic cost expense as well as all of the inherent confusion that would probably last for decades, I don't see it being justified any time soon. By the time we switch, we'll have to work out conversions to other intergalactic lifeforms units of measurement.

Fahrenheit is not "more accurate." 1 degree Fahrenheit is a smaller range than 1 degree Centigrade. Centigrade is more accurately specified in that there is less error with any given Centigrade statement in relation to the energy level of the mass being measured because of the precision by which it is defined. Celsius SI is determined from a specific measure between 0 K (absolute zero) and a specific state of water just above freezing in ratio to just above boiling (state change points). Fahrenheit was measured from the freezing point of water in units that were convenient and obvious to him at the time.

Of I suppose historical interest, IIRC the reason for the degree measurements he chose was that the scales he was using were circular and it was aesthetically desireable to have boiling and freezing of distilled water at 180' from each other (that is, opposite). Maybe that's apocryphal physics lore but it does illustrate where some of these things come from.

Yeah, seriously. We should all convert to base six. it's a clearly superior base to run calculations in, as it is divisible by the first two prime numbers 2 and 3 rather than 2 and 5. That and the brain can only comprehend up to 5 objects before it needs to start using symbols to represent them. Of course, we'd need to redo the metric system into the hextric system, but it'd be better in the name of efficiency.

or not....