Since when did 3/8" = 9.2mm?

The Si system is meant to define the units on an experimental basis that can be replicated easily and accurately anywhere anytime by anyone and be easily integrated with universal physical constants. The easy conversion to multiples/submultiples is just so we don't need to remember a senseless number of multiplying factors. For the SI system this is irrelevant but it makes life easier.
 
For further light reading on the metric vs imperial battle Google BWMA and UKMA🙂.

I for one was "fortunate" enough to learn imperial in my first few years of schooling and metric for the remainder. Subsequently (even today) I couldn't give a rats ar#e which one is used. Both systems are accurate and both suitable for day to day calculations, they have both had the time to prove themselves.
Yes metric in theory should be easier to teach but are we really that dumb to need a sign in the supermarket telling us a 500g item for $5 is $1 per 100g?
Day to day for me at home: need a 5/16" spanner 8mm will work, 7/16",11mm will fit, 9/16", 14mm will do the job and so on. Got a MPH speedo (most of my vehicles do), times the reading by 1.6 and it's close enough, do we need a scientific calculator to work out 50MPH is as near as doesn't matter 80KPH?
I work in healthcare and the "simplicity" of the metric system is also one of its greatest failings, look up "death by decimal point".

Cheers Rob.
 
There is no battle. Everything/everybody is metric/SI. It was decided some time ago and all countries agreed.

If you want, you can call it protecting the stupid because it makes things simpler so even stupid can work it out.

Problem is, part of being stupid is fighting tooth and nail everything that's meant to help you. It's a requirement. And there's a lot of ingenious stupid people out there as you have noticed at the supermarket.

And yes, we do need those labels because people are increasingly avoiding math in school since it is optional. Have a look at the last PESA study some years back and you'll see we are approaching 50% math illiterate at a basic functional level (that is every day functional, you know working out the change and such). Some states are there already. English is not much better.
 
I think Myanmar and Liberia are still dragging the chain on that one, but they have agreed in principle.
You have highlighted the problem, why learn maths when you have a calculator?
I guess dumb was a poor choice of words (uneducated may have been better) but we seem to be sending children to school for longer to be less functional without use of technology.
Spell check doesn't fix wrong context and realising you missed the decimal point on a calculator doesn't suck too much morphine, potassium or whatever else might kill you back out of a dead patient.
I can't wait until fully automated cars come out and anything that's not is banned from the road. It's much easier than trying to address the real problems and as a bonus there will a lot of cheap speed cameras listed on EBay.
 
And arithmetic and number theory is mind-fatiguing difficult. School number algorithms are only a useful start.
 
I think Myanmar and Liberia are still dragging the chain on that one, but they have agreed in principle.
You have highlighted the problem, why learn maths when you have a calculator?
I guess dumb was a poor choice of words (uneducated may have been better) but we seem to be sending children to school for longer to be less functional without use of technology.
Spell check doesn't fix wrong context and realising you missed the decimal point on a calculator doesn't suck too much morphine, potassium or whatever else might kill you back out of a dead patient.
I can't wait until fully automated cars come out and anything that's not is banned from the road. It's much easier than trying to address the real problems and as a bonus there will a lot of cheap speed cameras listed on EBay.

I've got it.

No. Stupid. I meant it.

Poorly educated are children who are abandoned in the street at birth and have no schooling. Children who have schooling available for free, computers for free, libraries, teachers, food and so on for free and they reject everything just because are just dumb. Because they do not even realise that it is all free. Free. It don't cost them anything. Zip. All they have to do is try but they donwanna.

Math is about thinking independently and checking your thinking independently with everything subjective out of the equation. Which is why people fear math. It is the only field where if you're wrong, you know it, there is no subterfuge, no opinion, no feeling and so on. You can't hide. People (especially modern people) hate that because it makes them feel bad about themselves and that's not allowed. People who persist build resilience and this is a transferable commodity. We don't have that anymore. If it don't work the first time, we give up.
 
No argument here.

I think we both got a little off subject.

Biggest decision I had this morning (day off) was whether to reply on my 6.7" phone, my 9.7" iPad or fire up the PC with its 19" monitor. I nearly said f##k it, I'm just going to lay back and watch reruns of American/British car shows on my 60" TV.
I just got back from walking one of my grandson's to school. On the way we saw a new looking Kenworth B-double parked which had a badge proudly proclaiming it had a 600 Horsepower (not HP) Cummins. He had a pat of the a horse that a young lady was exercising, which she said was 16 hands high. On the way back a couple of young scallywags on their 24" mountain bikes nearly cleaned me up. It was good to get home and kick off those size 10s I can tell you.
I will be going out later today however, so I will check the air pressure in my Citroen's 15" tyres (one has a slow leak) with my Chinese made air pressure gauge (which for some baffling reason is only graduated in PSI). I just have fire up the 2.5HP motor on my 9CFM compressor first.
There's a coffee shop a few miles 😉 up the road that makes a mean cappuccino, I'm going to order one of their 16oz cups and chill out for a while. As I live near a flight path I might even see if I can spot an airliner going over at 35 000' while I'm sipping on my brew.
 
This does all strongly suggest that all the prefixes indicating powers of 10, including centi, are part of the SI system


or

or

And this is the NIST saying it, which I consider to be highly credible body
 
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The SI is an MKS system, All sorts of conversions are possible, but are not part of the system.

When metrication occurred here, late 60s early 70s, it was far from by popular demand, indeed was costly, and a great many lectures occurred and documents published for the benefit of trades and technical occupations. Those who were there will remember.
 
I figured this thread was good a place as any.
I went to Bunnings today for a couple of bolts.
I try not to go there normally as they are a bit on the expensive side, but I was already driving past and only needed a couple.
Well, they hardly have any Imperial bolts at all.
The Zenith range of zinc hex head bolts and coach bolts they carried (and not too long ago), has all gone metric.
Went over to Mitre 10 and they weren't much better.
Ended up having to go across town to the nut and bolt shop. Casually mentioned to old matey about the change in the hardware stores.
He said although they still keep UNC and some Whitworth, they don't keep BSF and can't order BSF from their supplier any more.
I said "I bought some BSF off you not long ago"?
And he said, "someone from the Land Rover club came in and made an a offer on all our BSF stock and the boss sold it all to them".
🤬ing Land Rover driving mother 🤬ers.
I might have to join a Land Rover club now as well.🤔
 
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I figured this thread was good a place as any.
I went to Bunnings today for a couple of bolts.
I try not to go there normally as they are a bit on the expensive side, but I was already driving past and only needed a couple.
Well, they hardly have any Imperial bolts at all.
The Zenith range of zinc hex head bolts and coach bolts they carried (and not too long ago), has all gone metric.
Went over to Mitre 10 and they weren't much better.
Ended up having to go across town to the nut and bolt shop. Casually mentioned to old matey about the change in the hardware stores.
He said although they still keep UNC and some Whitworth, they don't keep BSF and can't order BSF from their supplier any more.
I said "I bought some BSF off you not long ago"?
And he said, "someone from the Land Rover club came in and made an a offer on all our BSF stock and the boss sold it all to them".
🤬ing Land Rover driving mother 🤬ers.
I might have to join a Land Rover club now as well.🤔
That's a fair rant. You need a proper shop nearby. 3/8" is 9.525 mm by my calcs. Happy New Year, apart from the bolts. It's a bit like the Austin 7 folk buying up all the Renault 750 pistons they could find a few decades ago!
 
That's a fair rant. You need a proper shop nearby. 3/8" is 9.525 mm by my calcs. Happy New Year, apart from the bolts. It's a bit like the Austin 7 folk buying up all the Renault 750 pistons they could find a few decades ago!
🤣 Just can't help but wonder, for the 50 years since we "went metric" hardware stores have kept Imperial bolts.

50 years.🤔 Maybe it's their "gold watch" moment?
"Thanks for coming" and all that.😉

Happy New Year to you too.
 
🤣 Just can't help but wonder, for the 50 years since we "went metric" hardware stores have kept Imperial bolts.

50 years.🤔 Maybe it's their "gold watch" moment?
"Thanks for coming" and all that.😉

Happy New Year to you too.
I rant regularly about all the non-metric stuff still out there. 50 years for heaven's sake!!!
 
I rant regularly about all the non-metric stuff still out there. 50 years for heaven's sake!!!
I think that the problem can be attributed to China and the USA. The US is very unlikely to ever follow most of the rest of the world and adopt the metric system. They consider it to be inferior. Despite the fact that they were very early adopters of a decimal currency. China supplies so much of the world's manufactured goods and labels things according to their market. As the US is probably their largest English speaking market, my guess is that is why we get stuff labelled in obsolete (to most of the world) Imperial units.
 
I think that the problem can be attributed to China and the USA. The US is very unlikely to ever follow most of the rest of the world and adopt the metric system. They consider it to be inferior. Despite the fact that they were very early adopters of a decimal currency. China supplies so much of the world's manufactured goods and labels things according to their market. As the US is probably their largest English speaking market, my guess is that is why we get stuff labelled in obsolete (to most of the world) Imperial units.
Yes, that's it. I guess the Hondas made in USA are metric but lots is not. I won't start on the well drilling industry with its US standards. We used to drill a 9 5/8" hole to 125 metres and nonsense like this....
 
TVs have been measured in inches again for a very long time. And now they are so big that you have to do a mental conversion to feet and inches in order to visualise the size, if you're not actually looking at it.
Another weird thing about US measurements. Have you noticed that they don't appear to use tons? They just use pounds. So they will state a ship's weight in thousands of pounds. Very hard to get your head around.
I recall reading an American technical magazine about 45 years ago. It might have been Scientific American. An excellent magazine at the time. They had a section for letters to the editor. A reader, in all seriousness, wrote explaining why the US commercial aviation industry was so far ahead of the Europeans. Lockheed and Boeing dominated and there was no Airbus. The reason that he gave was the greater accuracy and finer tolerances used by those companies. The US industry measured components using thousandths of an inch. The Europeans only had millimetres.
 
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