
the civilised world of SI
It's been a pleasant 295 Kelvins today.
We are sure our readers have been enjoying NASA's footage of the SpaceX Falcon 9 launch to the ISS earlier today, but amid the excitement, you may have missed another historic moment for the US space programme. Listen carefully... That's right, at around 1:10, a mission control operative explains: "Altitude 5.3 kilometres, …
I have little idea of what 71.33 degrees Fahrenheit feels like*. It's as alien to me as 71.33 degrees Rankine, Réaumur or Rømer. Kelvin at least has a sensible anchor for 0 degrees, but I can't see any justification for the intervals used. Why is the degree Kelvin a primary unit? Couldn't we define temperature in terms of something like the thermal energy in a Mole of Hydrogen?
*Ok, I know that it's colder than my body at 98.4 F and warmer than the best freezing mixture I could make (0 F).
Coat, in case 71.33 F is chilly.
Never mind the jingoism... There's the entrenched tail of legacy systems and social inertia. Not so much that them dang Yuro-peeans use it, but more along the line of "why should I have to re-learn how to measure things? The old system works just fine for me." Add to that the "well have to replace everything issue." There's an entire infrastructure that will need re-working - from our road sinage (and there's a LOT of that!) to machining and tools, down to the very fasteners we use.
That's a huge undertaking, and there frankly isn't much political will for it.
The Metric System (which most of us frankly *can* use quite well, when pressed) will simply have to continue its slow infiltration.
In many cases there's no practical purpose for changing anything, it's all cost and zero or minimum benefit. For example why go through the effort of (a) changing every single road speed limit sign in the US from miles to km (b) changing all US-made vehicle speedometers to show km/h, considering there are probably a huge number of US-made cars that have speedos only in mph and not in km/h (c) getting people used to the new system, especially since an old "50" will become a new "80", ie there will be a tendency for people to overspeed considerably if they misinterpret the sign.
The result will be a spike in speed-related accidents for a few years, which will gradually return to baseline (ie no improvement over pre-change that can be attributed to the change). It will be the same for volumes and weights of groceries etc. where there is a huge volume of things to be measured, and the measure only really matters within the US.
The only things that would benefit conversion to SI units are units used internationally, on a relatively small scale, and calculation-intensive metrics that would benefit having things divide neatly into tens and thousands rather than twelfths and sixteenths. So things like the space program, civil aviation, heavy industrial engineering
Mage, they've spent the last almost 40 years dismantling what had been one of the finest education systems in human history and replacing it with creationism, gossip, No Child Left Behind, and the Kardashians. (You may quibble about which of the four is more devastating to young intellects.)
As an American, I would be very surprised if there was any large-scale social, political or philosophical leadership coming out of the midsection of the North American continent for some years, if not decades. We're falling into the abyss of our very own Cultural Revolution, and we haven't yet even conceived of a 'bottom', let alone come within a parsec of hitting it. Things will get unfathomably worse before they start getting better, which is one reason why I'm no longer physically there.
well, to give my point of view, from Eastern Europe, (and maybe for most of the rest of the world) here the US is mostly viewed as a redneck country with the border rednecks willing to almost rape and anal probe you if you dare to visit and WILL kick arrest and deport you even for posting twitter jokes (TSA checkpoints). The USA's new logo for promoting tourism is: "Come and visit the USA, strip for the TSA!"
I had understood that the English measure used in the US dates from the end of the 13th century, but that John Wayne and «the West was won with/in/by feet and inches» had settled the matter for all time in the good old US of A ! But then again, John Wayne was probably a Jesus avatar - or was it the other way 'round ?...
Henri
the simplicity of the metric system allows you to show 1/3 of a meter as 0.3333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333333... and so on. The metric/decimal system hates those pesky thirds.
The amazing thing is that you can, if needed, still describe a third of a metre as a third of a metre.
Or you can give it as a decimal, then convert to metres / kilometres / centimetres / millimetres / ... by shifting the decimal point around.
By the way, for those in yankeeland fishing for a short way to say "kilometre", everybody I know measures both distance and speed in "kay" (so 60k can be 60km or 60kph, depending on context) and weight in "kilos" or "grams".
It is fine for NASA, or the private sector, to use metric. Likewise, if it was once, seemingly required that the American or British people had to learn it, that is no longer the case. Computers do the math. Double labels and such are common and easy for consumer purposes. Any progress in moving people to use metric terms in common speech will be entirely incidental, not intentional.
> We just can't use them because the conservative governments of both main parties don't think there are any votes in it.
Rather they know they'd get their sorry arses righteously tanned by an electorate who can't see why they should be pushed around.
If it ain't broken don't fix it.
It's broken, trust me. The world is now a place of global trade, and and one billion Chinese and one billion Indians, to say nothing of another few hundred million Europeans, all use metric. The 300 million in the US are hopelessly fighting a loosing, and expensive, war, as US companies cannot easily export or interoperate with global markets. It IS costing the US jobs, and profitability. The fact that no one wants to talk about that politically out of some sense of jingoism doesn't mean it isn't real.
It doesn't make sense from a practical standpoint — but then, the reason 'Murricans still use Imperial weights and measures has nothing to do with practicality and everything to do with emotional symbolism.
By pig-headedly sticking to Imperial units, and forcing all the companies that want to sell their products both in central North America and the Free(r) World to spend Saganesque billions of dollars in redundancy (labelling, packaging, inventory management and so on), 'Murricans are doing their considerable best to ensure that their products have a hard time being sold outside their borders, accelerating the out-of-control trade imbalance and hastening the demise of what once was the United States of America as a meaningful player in world trade. Maybe when world trade moves away from the US dollar as the global reserve currency, people will finally begin to understand how badly they've been screwed and why; my guess is they'll keep on lapping up the corporate propaganda that's replaced American news reporting and continue to blame every imaginable outside influence that scapegoats them having to take actual responsibility for and control of what in living memory was our country.
Things are going to keep accelerating downhill, and this is a poster-child-level reason for "why".
Paris for her corporately-groomed, information-free symbolism of what's wrong with America.
Imperial units? Now wait. There's the US gallon (3.78541178 liters) and the imperial gallon (4.54609188 liters). Not all gallons are created equally, and don't forget the last decimal, please. Then, there's the fact that the US does not realize it is already metric. NIST *officially* designates 1 inch as 2.54 cm. Laboratories, the medical field, and the US military uses SI units. In my kitchen, no.
Does the U.S. government require that:
- all our scales read in pounds?
- our food containers are measured in ounces and pounds?
- our drinks are usually measured in ounces, pints, quarts, and gallons?
- our meteorologists report the temperature in Fahrenheit?
- our sports teams measure their fields, courts, and arenas in feet?
- our construction industries primarily refer to feet and inches when specifying material sizes?
(side note: many government construction contracts use metric)
- our sportscasters talk about a linebacker's size in feet and pounds or a baseball pitcher's speed in mph?
AFAIK, the only thing our federal gov't can do is *recommend* that the states label their highways and roadways in kilometers and KPH.
IANAL, but that being said, I was a Political Science major, and I can answer alot of these questions for you.
>Does the U.S. government require that:
>- all our scales read in pounds?
No, but food scales in supermarkets and such are regulated by the individual state governments and as such are generally required to be accurate in pounds as well as in Metric.
>- our food containers are measured in ounces and pounds?
I believe the FDA requires it, as does the USDA, yes, though there are always metric weights on packages too, which I believe is also required.
>- our drinks are usually measured in ounces, pints, quarts, and gallons?
Same with food, the FDA and USDA require that measurements be in both metric and customary.
>- our meteorologists report the temperature in Fahrenheit?
Thats one Ive never understood, because a good number of divisions inside the National Weather Service, like the Space Weather Prediction Center and National Hurricane Center do most of their work in metric units. Celsius kind of sucks.
>- our sports teams measure their fields, courts, and arenas in feet?
No, but some sports governing bodies specify feet, yards, meters, kilometers or miles for their venues. Look at the International Rugby Board's laws for Rugby Union, it specifies that the field should be measured in meters. On the same coin, look at the NBA's rules for basketball, their measurements are in feet.
>- our construction industries primarily refer to feet and inches when specifying material sizes?
Alot of that has to do with building codes, which are a State issue, not Federal.
(side note: many government construction contracts use metric)
^^True, though Ive noticed that some GSA contracts tend to use customary for whatever reason.
- our sportscasters talk about a linebacker's size in feet and pounds or a baseball pitcher's speed in mph?
Well they could talk about sizes and speeds in metric, but not too many people would really understand.
The Feds could change everything over to Metric, it could be done legally, but it would cost much more than it would save and they realized this in 1977.
The better idea is to convert specific Agencies and Administrations, like NASA, that have a scientific, military related, or international mission as well as parts of specific other agencies like FEMA, which for instance still uses Americanized measurements for Radioactive contamination on their radiac sets and such, like the Rad, Roentgen, and Rem. While the very same radiac in use by the Army will measure in Sieverts and Grays.
You buy a £1.99 set of cups from the supermarket as my wife finally had to when using recipies from the other side of the pond.
Like all measurements there are implents to measure it. You just need to have them.
Just the same as someone without scales asking how they measure a kilogram of flour or something along that vein of thought.
"Had to learn it? We've been teaching metric units for the last sixty years."
you don't need to learn it, you just need to have it explained..once, ten minutes tops and thats it for life
no need to worry about insane conversion factors how many bushels per second in a foot pound per acre etc etc etc etc etc etc etc etc etc etc
all we need to do now is decimalise time, dump all them awkward 60's from the business and we'll be set
NASA Finally going Metric? NASA went Metric in 2007!
NASA Finally Goes Metric by SPACE.com StaffDate: 08 January 2007 Time: 04:00 PM ET
They just didn't bother converting the Shuttle documentation, but every new program uses metric units of measure, even if the parts are still based on inches. Too many mix-ups with metric tonne vs imperial ton, etc.
"My Jacket gets fourty rods to the hogs head and that's the way I likes it"
I recall speaking with some merkin infrastructure engineers a few years back and gently ribbing them about what is 7/16 of a mile in furlongs etc etc when they told me that in some states some utilities have been metric for years. causes no end of fun when the electricity company is laying cable by the yard and trying to avoid that big ol water main thats about twenty meters from the road intersection..
Makes you wonder why nasa never got some of them blokes to at least check their sums
"what is 7/16 of a mile in furlongs etc etc "
Well, it's 3½, obviously. And, since the meter is based on the furlong (no, really) that's easy to convert to French units - it's 700m.
The metric system is based on the odd proposition that if evolution selected ten fingers for us then it must be a good base for measuring things. It's not.
I get the whole factorisation argument, and i concede that 12's 16's etc make sense from that regard, and 10 is particularly useless for dividing stuff up.
But i think where decimal wins is in conversion factors, which (excluding those where time is a factor) always come out as 10's or multiples thereof. we all count in base 10 (speak for yourself earthling) it therefore makes sense to measure everything in the same base we use to count.
qed
(or not as the case may be)
by the way, the word Centigrade has been deprecated a long time ago (1948 if you don't feel like reading).
It may have been deprecated, but I don't know a word for the silliness of reversing the sense of Celsius!
On the original Celsius scale 0 was the boiling point of water and 100 was the freezing point of water at Standard Atmospheric Pressure. Centigrade was never subject to that particular ambiguity, but all temperature scales are quaintly irrational.
Hectometres. You don't hear that prefix much, though for some reason hectolitres is what brewers measure beer in. 'Sides, plenty of people say awkward things. Thousands of kilos? Megagrammes, really. Or more practically, tonnes. Millions of kilometres? Gigametres. And so on. Maybe NASA can do some good getting the rest of the country to get with the times, too.
40 rods = 1 furlong per 48, 54 or 63 gallons, depending on which sort of hogshead you are storing your fuel in (ale/beer/wine respectively). That is spectacularly crap consumption, even for a merkin gas guzzler. Or even an Abrams tank.
I'll get my coat. I clearly need to get out more.
I propose we alter the orbit and spin of Earth so that the result of dividing the time to orbit the sun by the time taken for a full rotation of the earth is exactly divisible by 10.
I propose 10 hours in a day, 10 days in a week, 10 weeks in a month and 10 months in a year. A year would contain 10,000 hours rather than the existing 8766 hours.
"Altitude 5.3 kilometres, velocity 225 metres per second, and downrange distance of six-tenths of a kilometre."
Those numbers seem overly-precise considering that they would have been outside the allowed significant figures allowance by the time he spoke the first word.
"Altitude 5. ah 5. ah 5.5 .6 .7 .8 .9 6.1 6.3 6.5 .7 .9 7!..."
0.6 mile is a KM (to at least 1 sig dig).
Did someone pull a NASA Mars Orbiter again? Maybe they really meant 1.6KM... 1/0.6 if you ignore the sig dig for a moment.
The only claim to fame for SI is ease of units conversion. At the bottom of the stack, until recently, were just lumps of iridium alloy stashed away in France. Purely arbitrary, might as well use the length of King somebody or others arm. Now of course, there are purely arbitrary numbers of wavelengths.... (for length), that at least pretty closely match the lumps of iridium, well, more or less unless you look really closely. As for mass, well, that seems to be shrinking for some reason but we won't go there. Probably a plot to debase gold or something by the French desperate to reduce their deficit by making it look like their treasury has more troy ounces (hahaha) of gold... well, if you convert to metric anyway.
We'll ignore the volt, what a debacle that was! No, not the Volt, the volt (we all know the Volt is a fire waiting to happen, or Ampera to anyone in the EU... I refer to the SI volt, which has two versions depending on when your deeply erudite research paper was written...).
We're still having to cope with:
feet and meters and nautical miles
for measuring distance, and
liters and US gallons and UK gallons and pounds and kilograms
for measuring fuel, and
pounds and inches and kilograms and centimeters
for measuring balance, and
knots and miles per hour and kilometers per hour
for measure speed, and so on and so on. Yes there are accidents which are partly or wholly caused by using the wrong units or getting conversions wrong.
Quote: But Britin is metric, last week I ordered 10m of 1/2" piping and a couple of 2m lengths of 2"x4".
And London is only 93 miles from here. But before I drive it, I am going to buy a pint of milk and top up my tank with fuel. Only a few litres ... because I get 45 miles-per-gallon... Boy am I glad we went decimal :/
before you go don't forget to check that you have a minimum of 1.6 mm of tread on those second hand tyres you bought for your 16 inch alloy wheels.
And don't go to close to the car in front, even at 20mph you need 6 metres to think and another 6 to brake (http://www.stoppingdistances.org.uk/simulator/Stopping_Distances.html)
2"x4" timber is never 2 x 4 inches anyway: the dimensions are the freshly-cut size (and for European timber are metric 50x100mm). As the wood dries, it shrinks.
Half-inch pipe is actually 22mm OD . No, that's not half an inch, and neither is the bore (inner diameter of "half-inch" pipe is 10mm), but then, "old" half-inch pipe wasn't half an inch either...
I lived in Germany for a while, and often heard people asking the butcher for a "Pfund" of meat - they got 500g, not a pound, and a pound wouldn't have been 454g anyway - the old Bavarian "Pfund" weight was 560g. And that is the reason why we all gave up on "traditional" measures: they weren't the same everywhere.
Even now, compare US and UK mpg figures. American cars are thirsty, but not that thirsty (also, the testing regimes differ, but that's something you can only see if you convert the quoted figures to litres per km)
I think you'll find that your 2"x4" came as 1.8 or 2.1m (i.e 6 or 7 feet!). Timber is sold in lengths which are multiples of 30cm (i.e ~feet). I'm amused by the way I can still buy, for example, "une livre de pommes" in France.
76 miles at 150mph could be more fun on my bike, but I'd need a bigger tank:(
ok ... for our american friends .. something very simple (in metric)
we have a hole in the ground
long 9 meters
wide 6 meters
deep 3 meters
we fill the hole with water
how much does the water weight in kg or pounds??
and how much time you needed to calculate the result ?
to help a little bit:
1 liter of water weights 1 kg
and
9 meters = 9.84251969 yard = 29 feet 621⁄64 inches
Control Words, Create Worlds. Life is just such a simply complex operation ...... but there is an extraordinary knack, known by only a few, in leading it with IT Command and Control of Future Events and Virtual Realities?
And shared as a question so that you have a choice to agree or disagree ........ but that would have no impact at all on the few who would growing and would be exercising such extraordinary knacks.
(honestly, I watch it for the science, I didn't realise Kari was a girls name).
Watching older MB broadcasts (on Quest) I was struck by how they plugged "the science" whilst talking in feet, inches and pounds. At some point they must have had a policy shift, because I noticed the newer ones (Discovery channel) are now metric. For me, the intersting point was they don't feel the need to explain the units - so clearly there's an assumption that their core demographic is familiar enough with metric.
My Dad's from "yourup", so I grew up metric at home too ...
Oh and lets not foget the Gallon which Americans still havent got right
The imperial (UK) gallon, defined as 4.54609 L, is used in some Commonwealth countries and was originally based on the volume of 10 pounds of water at 62 °F (17 °C). (A US liquid gallon of water weighs about 8.33 pounds at the same temperature.) The imperial fluid ounce is defined as 1⁄160 of an imperial gallon.
I think the only US unit that is bigger than the Imperial (avoirdupois) is the "fluid ounce" and then only by about a millilitre (or 1.5 ml if its the FDA's fluid ounce which is exactly 30ml).
Their Pint (both wet and dry) , Quart, Gallon, hundredweight and ton are all short measure.
Best line in a film ever:
"Brazil" where Bob Hoskins the Central Services repairman looks at the bung which doesn't fit the hole in the floor cut by the other Central Services department... and says "Oh no, they've only gone and gone back to bloody metric!"
http://en.wikipedia.org/wiki/Planck_units
After all, as the article points out, «... Planck units, by setting the numerical values of five fundamental constants to unity, nondimensionalizes and simplifies many fundamental equations of physics.»
Exceptions will of course have to be made for Reg bloggers LP and AO....
Henri
Before, NASA used both, metric and the other one... and had to do conversions .. I believe it's being blamed for a serious accident, perhaps a shuttle crashing, or just a rocket.. whichever.. wasted money at either rate... cuz someone messed up on the math conversions.. it makes sense to have a good standard.. about time. Maybe it'll save a life & money.