Cycling UK Forum

Jdsk wrote: ↑20 Nov 2023, 5:57pm

The first time that I realised how much trouble we are in was when Cameron sounded off about the teaching of Imperial units.

Jonathan

PS: Whatever happened to him?

What, Cameron Mackintosh? I expect he's busy working on a hit West End musical about the Paris Conference of 1875 and the Metre Convention.


Ohhh, that Cameron.

plancashire wrote: ↑20 Nov 2023, 10:24pm
Britain is notorious for creating "systems" that are barking mad. The mixed metric-imperial system is a good example. Others are postcodes with spaces (with Canada), BA screw sizes where big numbers are smaller threads and you use only the even ones, SWG wire sizes (another inverse scale), model railway scales and anything where you keep adding zeroes to go off the end of the scale - I could go on....

[Light blue touchpaper and retire to a safe distance.] Kilometres or kilometers?

The Italian BB size of 36mm x 24tpi for example?
Meter: measuring instrument.
metre: unit of length

(IMO)

I started using cyclocomputers when I was living abroad, so obviously set them up in km, and then continued that way. Then there's the usefulness of OS mapping, the influence of audax, also of continentally glamourous sport.

hoogerbooger wrote: ↑19 Nov 2023, 3:23pm I would have thought it is largely an age thing. I am of post decimalisation age and did sciences at school/uni. The thing that annoys me is that we still use miles.
( having said that I can just about cope with beer sold in pints..........as long as someone else is paying!)

The last pint I bought in a pub was £5.50, which reminded me why I seldom go to pubs nowadays!

And talking of bars... I never got out of the habit of thinking in psi for tyre pressure or calculating gears in gear inches.

plancashire wrote: ↑20 Nov 2023, 10:24pm If you want a real challenge, try agricultural units. Chinese land areas? USA bushels are particularly bonkers, being based on volume then standardised to a weight which depends on exactly what you are measuring. Hops use a German version of the hundredweight called a zentner.

Oh, the metric hundredweight, which can be 50kg or 100kg, depending where you are (and perhaps what you're weighing). Also the use of pound to mean, often, 500g, but sometimes another weight. Why, having invented a logical scale, do we complicate it by adding names which have no place?

Jdsk wrote: ↑19 Nov 2023, 7:03pm

Biospace wrote: ↑19 Nov 2023, 6:59pm ...
However at least one space craft - the Mars Climate Orbiter - has been lost due to a contractor assuming the usual nautical miles were the scale for writing the landing software, whereas the contract specified metric.
...

The discrepant units were those of impulse, not distance:
https://en.wikipedia.org/wiki/Mars_Clim ... of_failure

Jonathan

Interesting, I did not know that!

I'm happy to forgive this popular fallacy, as almost everyone understands the "nautical miles vs km" concept, but very few Joe Public would understand this:

Specifically, software that calculated the total impulse produced by thruster firings produced results in pound-force seconds. The trajectory calculation software then used these results – expected to be in newton-seconds (incorrect by a factor of 4.45)[16] – to update the predicted position of the spacecraft.[17]

Bmblbzzz wrote: ↑21 Nov 2023, 10:27am... the use of pound to mean, often, 500g, but sometimes another weight. Why, having invented a logical scale, do we complicate it by adding names which have no place?

Old habits die hard. The French still call 500g 'un livre', after what, nearly 250 years.

nirakaro wrote: ↑21 Nov 2023, 10:45am

Bmblbzzz wrote: ↑21 Nov 2023, 10:27am... the use of pound to mean, often, 500g, but sometimes another weight. Why, having invented a logical scale, do we complicate it by adding names which have no place?

Old habits die hard. The French still call 500g 'un livre', after what, nearly 250 years.

The current round of French metrication started in 1837/1840. Because they had reverted to mesures usuelles under the Empire. Another example of politics interfering in metrology.

And at least the livre was redefined as a nice round number of metric units. British Imperial units are now defined in terms of SI units but at roughly their previous value and without rounding.

Jonathan

mattheus wrote: ↑21 Nov 2023, 10:44am

Jdsk wrote: ↑19 Nov 2023, 7:03pm

Biospace wrote: ↑19 Nov 2023, 6:59pm ...
However at least one space craft - the Mars Climate Orbiter - has been lost due to a contractor assuming the usual nautical miles were the scale for writing the landing software, whereas the contract specified metric.
...

The discrepant units were those of impulse, not distance:
https://en.wikipedia.org/wiki/Mars_Clim ... of_failure

Interesting, I did not know that!

I'm happy to forgive this popular fallacy, as almost everyone understands the "nautical miles vs km" concept, but very few Joe Public would understand this:

Specifically, software that calculated the total impulse produced by thruster firings produced results in pound-force seconds. The trajectory calculation software then used these results – expected to be in newton-seconds (incorrect by a factor of 4.45)[16] – to update the predicted position of the spacecraft.[17]

A couple of examples of errors caused by mistaken units of distance:
https://en.wikipedia.org/wiki/Unit_of_m ... plications

Jonathan

Jdsk wrote: ↑21 Nov 2023, 10:55am ...
And at least the livre was redefined as a nice round number of metric units. British Imperial units are now defined in terms of SI units but at roughly their previous value and without rounding.

Yes. I believe the inch is defined as 25.4mm.

The Germans have a Pfund, which is also 500g. I sometimes hear older people using it in the weekly market. TV and computer screens in Germany are usually measured in Zoll (inches)!

I think the persistence of inches in consumer products (including bicycles) is largely due to the technological and cultural influence of the USA, as well as its huge consumer market.

Interesting that France reverted back to pre-metric (I suppose pre-Revolutionary in this context) measures. I hadn't known that. But the political-cultural influence in measurements is probably inevitable, they (all three: politics, culture, measurements) are after all a human filter on reality.

Bmblbzzz wrote: ↑21 Nov 2023, 12:11pm .....But the political-cultural influence in measurements is probably inevitable, they (all three: politics, culture, measurements) are after all a human filter on reality.

Absolute! Which is why it can often be beneficial (in terms of getting to apprehend a bit more of whatever reality is) to ignore cultural filters of, in this case, dimensions in favour of just contemplating length, distance, thickness and the like as though we were a more simple animal without a head full of memetic infestations.

How does it feel, look, sound like or even smell!? These basic senses can tell us a lot about dimensions and all sorts of other aspects of things without sticking a geet ruler on them. For example, noting wind direction with skin and smell-strength of the midden with the nose, one might be able to know just how far down the lane the lake of rotting cowclap is located.

This book contemplates the wider point:

https://www.goodreads.com/book/show/160 ... of-animals

One of the main British influences around the world = 4 ft - 81/2 inches.
How did we come up with that measurement ?
Roman chariots at a guess ?

francovendee wrote: ↑20 Nov 2023, 4:29pm

al_yrpal wrote: ↑20 Nov 2023, 11:09am I have been bidimensional since the mid 60s when I was chosen to metricate the engineering company I worked for. My bible was the DIN standards.

Anyone kno wot a Slug is?

Al

Al, Being bidemensional does it let you join Pride marches?

Never used a slug, is it to with weight?

The Googler in chief got it. Dont know whether the yanks still use it?

Al

cycleruk wrote: ↑21 Nov 2023, 1:53pm One of the main British influences around the world = 4 ft - 81/2 inches.
How did we come up with that measurement ?
Roman chariots at a guess ?

That widely shared belief has been looked at by Snopes:
https://www.snopes.com/fact-check/railr ... -chariots/

Bmblbzzz wrote: ↑21 Nov 2023, 10:21am ... I never got out of the habit of thinking in psi for tyre pressure or calculating gears in gear inches.

Gear inches are meaningless to me, but if you cite metres developed, I understand and can predict the slope it'd get me up.

(Now that we've left the EU can we take control of units and go completely si/ metric...)