Kilometers or Miles?

[Mike Sales]

famous mountain heights (4404).

I recognise that one.
How about 3210 or 3560?
Perhaps beneath a Scotsman's notice.

[ChrisF]

I’ve found it a useful rule of thumb that the number of OS kilometre grid squares I plan to pass through will be about the number of miles I’ll ride.

You must ride wiggly roads! The diagonal of a km square is about 0.89 miles, and many grid squares you pass through will be just cutting a corner.

[Jdsk]

Simple I'm English so MPH, pounds and ounces stones, feet and inches and I still occasionally say to myself, "how much, 10s for a X or £1-10s for a coffee

Which of the many feet and inches in general use until recently do you recommend? The Prussian zwolf zölle pro ein fuß?

Luckily no one under the age of 50 in the UK has had their time wasted at school on his nonsense measuring system.

Unfortunately traditional British units are still included in the National Curriculum for England. This residue is of course for two reasons: the incomplete national migration and political appeals to traditionalism.
https://www.gov.uk/government/publicati ... s-of-study

Including:

• understand and use approximate equivalences between metric units and common imperial units such as inches, pounds and pints

And in Scotland:
https://education.gov.scot/media/s5edgt ... hmarks.pdf

• Shows awareness of imperial units used in everyday life, for example, miles or stones.

Jonathan

[Bmblbzzz]

My German Yamaha motorcycle failed it's first MOT because it didn't have MPH on it's speedometer. ( our MOT is different than GB -- in NI it's government run controlled in MOT centres not garages -- they don't fix just pass or fail. ) I arrived at the retest with an overlay sticker and passed. ( more expensive booking the retest than a box of overlay stickers ). Ridiculous but it means you're off the road until the retest so very serious if you depend on that mode of transport. ( I don't )

Do they check digital speedometers as well?

[Jdsk]

My German Yamaha motorcycle failed it's first MOT because it didn't have MPH on it's speedometer. ( our MOT is different than GB -- in NI it's government run controlled in MOT centres not garages -- they don't fix just pass or fail. ) I arrived at the retest with an overlay sticker and passed. ( more expensive booking the retest than a box of overlay stickers ). Ridiculous but it means you're off the road until the retest so very serious if you depend on that mode of transport. ( I don't )

Do they check digital speedometers as well?

The checks:
https://www.infrastructure-ni.gov.uk/si ... 3%20mm.pdf

Jonathan

[rogerzilla]

People use units that give comfortable numbers. So inches are too big for small or precise things, and they use mm. But cm are too small, so they use inches. Yards and metres are close enough that they get equally used. Kg are a bit small for measuring people, so they use stones. And so it goes.

You'll never make a full SI system stick for everyday use. No scientist or engineer* would struggle with anything else, but I bet most still use inches and miles outside work.

*US engineers do occasionally use "customary units". It is really not easy for calculations, especially heat and power.

[Jdsk]

...
No scientist or engineer* would struggle with anything else, but I bet most still use inches and miles outside work.
...

Do you mean in the UK or wider? In the UK miles have a privileged position because of speed limits and signposts. That means that in practice it isn't a matter of choice,

Jonathan

[Fasgadh]

4404 is the only one I know - because of all the fours.

The grid square counting is a good trick, but it slightly overshoots. If you are catching a short corner traverse, you will pay for it with a long diagonal in another square.

[matt_twam_asi]

Which of the many feet and inches in general use until recently do you recommend? The Prussian zwolf zölle pro ein fuß?

Luckily no one under the age of 50 in the UK has had their time wasted at school on his nonsense measuring system.

Unfortunately traditional British units are still included in the National Curriculum for England. This residue is of course for two reasons: the incomplete national migration and political appeals to traditionalism.
https://www.gov.uk/government/publicati ... s-of-study

Including:

• understand and use approximate equivalences between metric units and common imperial units such as inches, pounds and pints
[snip]

I think this (within the context of the whole document) is making clear the understanding that the the UK still uses imperial units, so one may need to convert into them from time to time. The rest of the guidance uses metric units where a choice between metric and imperial would be relevant. Imperial units are history, a side note, rather than something that takes up any significance in the mathematics curriculum.

[Cowsham]

My German Yamaha motorcycle failed it's first MOT because it didn't have MPH on it's speedometer. ( our MOT is different than GB -- in NI it's government run controlled in MOT centres not garages -- they don't fix just pass or fail. ) I arrived at the retest with an overlay sticker and passed. ( more expensive booking the retest than a box of overlay stickers ). Ridiculous but it means you're off the road until the retest so very serious if you depend on that mode of transport. ( I don't )

Do they check digital speedometers as well?

The checks:
https://www.infrastructure-ni.gov.uk/si ... 3%20mm.pdf

Jonathan

Thanks Jon that was well referenced. An MOT fail here is a serious problem for anyone who relies on a car for work or transport as a retest can take weeks to get a booking not to mention how the car will be fixed as most mechanics are booked a month in advance. We don't have the bus and rail connections England has.

[Jdsk]

4404 is the only one I know - because of all the fours.
...

One of the interesting features of the Imperial system (and USCU and others) is the large number of numbers that don't have an obvious explanation: 12, 14, 16, 22, 112, 640, 1760, 4840, 5280, 63360...

I guess that many readers of this forum can immediately identify most of those...

Jonathan

[Cowsham]

People use units that give comfortable numbers. So inches are too big for small or precise things, and they use mm. But cm are too small, so they use inches. Yards and metres are close enough that they get equally used. Kg are a bit small for measuring people, so they use stones. And so it goes.

You'll never make a full SI system stick for everyday use. No scientist or engineer* would struggle with anything else, but I bet most still use inches and miles outside work.

*US engineers do occasionally use "customary units". It is really not easy for calculations, especially heat and power.

Painting decorating DIY I'll use inches cos the numbers are smaller and easier to remember while holding the tape measure but at work SI units are essential. Sometimes you have to use standards ( calibrated devices ) to measure various different units on various production equipment so sometimes I have to calculate what I should expect to see on the Standard.

A good example is a mass flow controller that in production is interfaced with a machine that needs to show how much gas or fluid is being delivered to the process but you only have a standard that has been calibrated at a certain standard temperature and pressure and maybe measuring hydrogen mass flow at 20° c with a standard calibrated in nitrogen or even air at zero °c . This is where SI units and the relationships between them are invaluable.

I've had to convert from imperial units where older machines from America have been employed but work in SI units and converting back at the end.

[rareposter]

One of the interesting features of the Imperial system (and USCU and others) is the large number of numbers that don't have an obvious explanation: 12, 14, 16, 22, 112, 640, 1760, 4840, 5280, 63360...

So much of it is derived from Middle Age farming measurements. Furlong is short for One Furrow Long - the length that an oxen ploughed before needing a rest - but it's also related to acre, an acre being one furrow long and one chain (22yds) wide. Other measurements like chains and miles are related to furlongs; a mile is 8 furlongs.
The history behind it all is quite interesting and dates back to - in many cases - Roman and Greek times.

[Bmblbzzz]

4404 is the only one I know - because of all the fours.
...

One of the interesting features of the Imperial system (and USCU and others) is the large number of numbers that don't have an obvious explanation: 12, 14, 16, 22, 112, 640, 1760, 4840, 5280, 63360...

I guess that many readers of this forum can immediately identify most of those...

Jonathan

Some of them but certainly not all.
12 – inches to a foot, or pennies to a shilling
14 -- lbs to a stone
16 -- ?
22 -- yards to a chain
112 -- ?
640 -- acres to a square mile
1760 -- yards to a mile
4840 -- square yards to an acre
5280 -- ?
63360 -- ?

What they all have in common is being even numbers, which is in itself slightly odd (pun not intended but I'll leave it).

[Cowsham]

4404 is the only one I know - because of all the fours.
...

One of the interesting features of the Imperial system (and USCU and others) is the large number of numbers that don't have an obvious explanation: 12, 14, 16, 22, 112, 640, 1760, 4840, 5280, 63360...

I guess that many readers of this forum can immediately identify most of those...

Jonathan

Some of them but certainly not all.
12 – inches to a foot, or pennies to a shilling
14 -- lbs to a stone
16 -- ? 16 oz = 1 lb
22 -- yards to a chain
112 -- ? Took me a little longer to remember a hundredweight
640 -- acres to a square mile
1760 -- yards to a mile
4840 -- square yards to an acre
5280 -- ? 1760 yards = mile so = 5280 feet
63360 -- ? Inches in a mile

What they all have in common is being even numbers, which is in itself slightly odd (pun not intended but I'll leave it).