# Has [i]any[/i] country gone fully metric?

In the colum on the metric system http://www.straightdope.com/classics/a4_013.html Cecil explores the reasons why we (the US) has failed to adopt the SI system (for the sake of this post I am treating metric and SI as being one and the same).

The basic units in the SI system are:
[ul]

• length–meter
• mass–kilogram
• time–second
• electric current–ampere
• thermodynamic temperature–kelvin
• amount of substance–mole
• luminous intensity–candela
[/ul]
Has any country fully adopted all of these units? Sure the United States as a whole never caught on to the distance or mass measurements. Since these follow a decimal system using them certainly makes life easier. But does anyone follow a decimal time standard? How many of you can rattle off your age in seconds? For a back-of-the-envelope I get mine as roughly 1 Gs.

If my memory serves me correctly, at one time the French tried to put a decimal time standard in place but it flopped. If the inventors of SI couldn’t pull it off could anybody?

I don’t know of any country where Kelvin is used in day-to-day life for temperature, or Joules are used instead of calories for food packaging (though I’ve seen food where the energy content was listed in both, calories and Joules). My impression is that since °C only differs from K by the offset of the difference between the freezing point of water and absolute zero, that °C is in practice considered part of the the SI unit system. As far as Ks or Ms being used in place of hours, mintes, days, I don’t think I’ll see that happen in my lifetime.

For information on the French decimal calendar, as is usual in these cases, you need look no farther than the Straight Dope, fount of all (or at least most) knowledge.

Who decided the day should be divided into 24 hours? (The column (including Slug Signorino’s illustration) can also be found on pages 125-126 of Cecil Adams’ book «The Straight Dope».)

Also, there’s the important point that the SI units are not synonymous with metric. All SI is metric, but not vice-versa. There’s also the CGS system, for starters, where the standard length measurement is the centimeter, the standard mass is the gram, and the standard unit of electric charge is the ESU, which isn’t even directly consistent with the SI coulomb. Other units such as the parsec, the Angstrom, the barn, and the calorie are typically treated as metric units, even though they don’t really fit into either the MKS (SI) or CGS systems.

If I understand correctly, commercial aviation still specifies airplane altitudes in feet, so the answer for any country with international service is “no”.

(Any one else notice that, after registering nearly two years ago, this is only crc’s third post. And I thought I didn’t post very much…)