Someone from this sight has gone to a physics forum trying to push imperial on these people. Note though from the chart the overwhelming majority of people polled have chosen SI.


http://www.physicsforums.com/showthread.php?threadid=14992

When (if) American engineers and scientists use the fps instead of SI they don't suffer the same disadvantges of using non-metric as in ordinary everyday use. The issues are not the same.

In fps the foot replaces the metre and the pound replaces the kilogram, as does the poundal or pound-force (not both) replace the newton.

In scientific applications of fps the foot and pound are decimalised. They don't use ounces and stones or inches and yards etc and they don't use fractions. So the disadvantages of non-decimal are not an issue.

In that sense it could be argued that SI isn't really any better than fps it's just different with a different arbitray choice of base units.

The real issue is to do with unnecessary proliferation. Why recognise two different completely incompatible systems for the same job when neither offers any special advantages whatever the application?

Nowadays the vast majority of work in science and engineering crosses geographic and lingustic boundaries. So it makes sense to standardise on one only.

Since fps has no defined units for electromagnetism there is no real contest.

One thing I find irritating is the suggestion that fps units are English and so should be used out of loyalty to the English speaking world. The international committees that define the conventions for SI have given the English language pride of place! Look at all the symbols and abbreviations, they are initials for the English spelling of all the units. Not to mention key unit names like newton, watt and joule named after English speaking Brits.

How ungrateful can we be when they honour us like this and all we can do is throw it back them!

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The real issue is to do with unnecessary proliferation. Why recognise two different completely incompatible systems for the same job when neither offers any special advantages whatever the application?
>>
But they do offer special advantages. For example, the metric system has no convenient mass unit for measuring food - the gram is too small and the kilogram too big. In the US, the imperial system has the advantage of being familiar to consumers.


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Look at all the symbols and abbreviations, they are initials for the English spelling of all the units.
>>
They are actually initials for many spellings of the units.
km stands for kilometer/re in English, kilometro in Spanish, kilometre in French, etc.

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Not to mention key unit names like newton, watt and joule named after English speaking Brits.
>>

and you can add Kelvin, Gray and Farad so to the list (Farads aer named after Faraday). You can also add Henry (American) to the list while Volta and Tesla emigrated to the US.

Not a bad collection out of 17 scientists and engineers who have been honoured by having SI units named after them.

He's following Bryan around now.

Creepy.

Martin, there is a difference between the two portions of the SI system. One part consists of the everyday units that people use in daily life. These include metre, gram, litre, etc. These everyday units are old metric, and predate SI. Then there are the scientific units, the ones you listed above plus others.

It is the scientific units that are named after British people, not the everyday units. But it is the everyday metric units that we find objectionable, not the scientific ones. So it doesn't make sense to say that Britain should adopt the old metric units just because the newer ones were developed and named after British people.

Bud

Would you please expand on your viewpoint?

You suggest that there are two parts to SI. Can you suggest which units fit into each part?

And why do you suggest that "everyday units" are objectionable?

I'm not fishing - just looking for some justification of your statements above......

Very good question, Beranger. I'm glad you asked.

I did not mean to imply that SI is formally divided into 2 parts. I meant that most people see it as such. There are some SI units that the general population uses in day-to-day life, and others that only engineers and scientists use. I know they are all under the umbrella of SI, but most common people are not familiar with the scientific units, so it doesn't make much sense to say that they should use them because the technical units come from British origins.


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And why do you suggest that "everyday units" are objectionable?
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As a pro-imperial, I do not believe that people should be forced or encouraged to use metric units where they haven't been in the past. However, this statement only applies to the everyday units, not the technical ones.

"""He's following Bryan around now."""


Actually, I was doing a google search on gravitational based units and one of the searches lead to the physics site. It wan't intended.

I should have looked deeper to see if Bryan actually discussed anything related to the topic of physics. Maybe Bryan can tell us.

I did get a kick out of Bryan claiming to be a member of the dozental society. I wonder if he is also a member of the flat earth society. Are you Bryan?

"""As a pro-imperial, I do not believe that people should be forced or encouraged to use metric units where they haven't been in the past. However, this statement only applies to the everyday units, not the technical ones. """


But forcing them or encouraging them to use imperial is ok? How far into the past do you go? Metric units have been used by common people the world over, some for 200 years others only a generation. Are these people complaining? Why should you be then?

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There are some SI units that the general population uses in day-to-day life, and others that only engineers and scientists use.
>>

Such as UK bus-drivers, lorry-drivers and road maintenance workers who use kilometers and km/h on a daily basis.

Not bus drivers.
Check their speedo's next time you are on one with the "public".


"I wonder if he is also a member of the flat earth society. Are you Bryan?"

Are you hoping he's a member just to keep you company.

Again, 'Creepy'.

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Not bus drivers.
Check their speedo's next time you are on one with the "public".
>>

I have - The have km/h is BIG letters, mph in small letters and the odometer is in km. They also keep their tachograph records in km and km/h.

I've seen them either way around.

But they have to have mph since all the roads in the UK are that way.

BTW - the buses in spain have big kph and small mph.

....and I don't think buses have tachographs (like coaches and lorries do).

Busses are exempt from tachographs within the UK only if they are following fixed timetables and drivers are following a prepared roster and a copy of trhe roster is in the driver's cab.

Bud:
"They are actually initials for many spellings of the units.
km stands for kilometer/re in English, kilometro in Spanish, kilometre in French, etc."

Stan:
Not in all cases. Italian for kilo is chilo, German for centi is zenti

The committees that devise the system gave priority to the English Language for the symbols because it is so universal. I stand by the point that SI is just as English as anything else and rejecting it on the basis of a misplaced sense of loyalty to the English speaking world is petty and ungracious.

Bud:
"But they do offer special advantages. For example, the metric system has no convenient mass unit for measuring food - the gram is too small and the kilogram too big."

Stan:
Metric does have the decagram and hectogram if people really can't over 10 or 100. In any case why do people stick to feet for altitude? I don't hear anyone complaining that the foot is too small.

Thanks Bud

But where do you feel the base SI units of temperature, electrical current and time fit in? Are they everyday or scientific?

I would suggest that they all affect my everyday life.

I would agree that the base units of Candella & Mole have very little relevance to most of us though!

They were adopted, not invented, by SI.

Realisation of the Candela

http://www1.bipm.org/en/si/si_brochure/appendix2/photometric.html#history

SI brochure, Appendix B, section 7

The definition of the candela is expressed in strictly physical terms. The objective of photometry, however, is to measure light in such a way that the result of the measurement correlates closely with the visual sensation experienced by a human observer of the same radiation. For this purpose, the International Commission on Illumination (CIE) introduced two special functions V() and V'(), referred to as spectral luminous efficiency functions, which describe, respectively, the relative spectral responsivity of the average human eye for photopic (light adapted) and scotopic (dark adapted) vision. The more important of these two, the light-adapted function V(), is expressed relative to its value for the monochromatic radiation to which the eye is most sensitive when adapted to high levels of illuminance. That is, it is defined relative to radiation at 540 x 1012 Hz which corresponds to a wavelength of 555.016 nm in standard air.


The CIPM has approved the use of these functions with the effect that the corresponding photometric quantities are defined purely in physical terms as quantities proportional to the integral of a spectral power distribution, weighted according to a specified function of wavelength.

Since the inception of the SI, the candela has been one of its base units: it remained a base unit even after being linked, in 1979, to the derived SI unit of power, the watt. The original photometric standards were light sources, the earliest ones being candles, hence the name candela as the name of the photometric base unit. From 1948 to 1979 the radiation from a black body, Planck radiation, at the temperature of freezing platinum was used to define the candela. Today the definition is given in terms of monochromatic radiation rather than the broadband radiation implied by the black body definition. The value 1/683 watt per steradian which appers in the present definition was chosen in 1979 so as to minimize any change in the mean represntations of the phomometric units maintained by the national standards laboratories.

The definition gives no indication as to how the candela should be realized, which has the great advantage that new techniques to realize the candela can be adopted without changing the definition of the base unit. Today, national metrology institutes realize the candela by radiometric methods. Standard lamps are still used, however, to maintain the photometric units: they provide either a known luminous intensity in a given direction, or a known luminous flux.

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Such as UK bus-drivers, lorry-drivers and road maintenance workers who use kilometers and km/h on a daily basis.
>>

I would classify km and km/h as everyday units. Same with temperature in celsius. Scientific units would be moles, coulombs, amps, etc.

Those same lorry drivers (etc) would converse in miles and mph, incidentally.

Funny how you can make the writing smaller but its the bigger writing that's ignored!

:-D

Bud:
"I would classify km and km/h as everyday units. Same with temperature in celsius. Scientific units would be moles, coulombs, amps, etc."

Stan:
Amps are everyday units surely? Fuse ratings, electric cable etc.

Most of the SI base units are familiar to people in everyday life - metre, kilogram, second, ampere.

You don't need to be a scientist to understand kelvin either. It's used in photography (colour temperature of lighting).

There are quite a few of the derived units too - joule, watt, volt, hertz, Celsius, square metre, cubic metre, etc

Metric isn't just for scientists it's for everyone.

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Stan:
Amps are everyday units surely? Fuse ratings, electric cable etc.
>>

Stan, I challenge you to find someone besides a scientist, engineer or person interested in studying measurements who can answer the following two questions correctly.

1. What does an amp measure? Power, current, voltage, or charge?
2. If you have 1 amp, how much charge is flowing per second?