Measurement and number

[Ekij]

We're getting well http://www.btinternet.com/~boxzone/Other/Smilies/Smilie_Offtopic.gif however ...

Perhaps this should be in Pet Hates, but I really dislike it when [news articled] give figures in two units without applying common sense. They need to learn about significant figures and orders of magnitude. I can't find an example at the moment but an example might be, "Fred Bloggs cycled a total distance of 3000 miles (4828km) in his epic journey.". Now, I'm no expert but Fred wouldn't have cycled exactly 3000 miles so converting it to 4828km is just unnecessarily precise - in that instance, why not say 4800km?

I actually 'reported' this as an error to the BBC once and had a short discussion with the journalist who wrote the article who just couldn't understand what I was saying. I gave up in the end :)

[lightsource]

I think possibly Ekij, you have to remember that said journalists are writing articles for the general public, who have no knowledge whatsoever of this industry. And their articles reflect that ( as does their knowledge!)

[paulears]

I've always looked on these kind of articles as material designed for early teens to read - kind of technical comic copy. We're only complaining because we know, the people who don't, will be better informed than they were. My friend is a physiotherapist and she often uses middle school biology material with colourful diagrams to explain to her patients what she is doing, when the professional material is simply far too complex, and unnecessarily so. Some poor journo gets asked to produce copy, gets a graphic type to draw it, and simplify it and voila, we've seen the result. We've all seen the diagrams of how a nuclear power station works - and I bet the 'nuclear power station engineer' forum finds plenty wrong with those!

[Ekij]

I think possibly Ekij, you have to remember that said journalists are writing articles for the general public, who have no knowledge whatsoever of this industry. And their articles reflect that ( as does their knowledge!)

Conversion of units does not require a knowledge of any industry. It requires a little common sense.

The purpose of journalists is (should be) to inform the masses. It helps to do this if the journalist is informed themselves. I consider the ability to convert between units as much a part of the ability to write as is forming a grammatically accurate sentence. If the journalist can't do this they are under trained for the position.

[paulears]

I always found the measurement units are really badly done at school. I have just asked my 16 year old son, who's just done his GCSEs a question about centimetres. He had no idea. So I asked him if him and his friends used imperial or metric, and they do everything in feet, inches and yards.

 

So I'd say that in newspapers, tv and radio, talking in metric is still pointless as it isn't just elderly people who don't understand it!

[Ekij]

I feel a thread split coming on here ...

I asked my 16 year old if he and his friends used imperial or metric, and they do everything in feet, inches and yards.

 

So I'd say that in newspapers, tv and radio, talking in metric is still pointless as it isn't just elderly people who don't understand it!

Three things here:

1] The school should be teaching metric (I thought it was a legal requirement these days but I can't quote chapter and verse on this so I might be mistaken), imperial as an option but the U.K. went metric years ago (with special dispensation on pints and miles). The real world still uses both so children need to learn both.

 

2] Units should be presented in both formats and then people can take whichever they prefer. (Some countries struggle with presenting all information in two languages, by comparison a few unit conversions are trivial). It makes sense for the person presenting the information to do the conversion once rather than have hundreds or thousands of individuals have to do the conversion when they each individually encounter the information.

 

3] The underlying problem here is implied accuracy not units. If a rocket reached 300m high this almost certainly wasn't measured with an accuracy of 1m so converting it to 984ft is misleading. If a building is 300m high it may well be exactly 300m high and 984ft is an accurate conversion.

[Ben Langfeld]

I always found the measurement units are really badly done at school. I have just asked my 16 year old son, who's just done his GCSEs a question about centimetres. He had no idea. So I asked him if him and his friends used imperial or metric, and they do everything in feet, inches and yards.

 

So I'd say that in newspapers, tv and radio, talking in metric is still pointless as it isn't just elderly people who don't understand it!

 

I've never seen a textbook working in imperial measurements. I'm guessing your son's school is one of less than a handful schools with very very odd maths departments.

[paulears]

Sorry, I didn't explain this well. The schools taught in metric, and the exams were in metric, but the kids can't relate these to the imperial they think in.

 

 

I asked him to show me a metre - I got about 600mm, I asked him for a yard, and got three feet! My older son (21) is here with his friends and I've just done a quick survey. I held my hands apart and the answer I got was..... "half a metre", and they all looked and nodded. I asked them to estimate the size of the room in metric and not one could. Something seems wrong here. Try the test on people you are with and report back. In a mo, I'll split the thread.

[Andrew C]

I almost always:-

 

Estimate in Imperial

Draw in Metric

Set-build in Imperial (8 and 10 x4 sheets and all that)

Measure in whichever system is closest to a sensible number on the tape! 6', not 1828mm

 

Oh, and I hate cm. Please lets all use mm or m or ' & ".

 

And pints, I like pints! :(

 

 

Let's not forget why the Mars lander thing buried itself on landing... NASA using ft/lbs and the rest of the world N/m!

[Glyn Edwards]

Very often I see sets built from plans drawn in metric. Then the chippies get on stage and it'll be "kick it this way an inch" or "trim that by a quarter"! People will work in units they understand, its natural! When Britain went metric (1971?) everything carried on being imperial, its just how neatly it was expressed that changed. Both Rosco and Lee gels come in rolls that are 7.62m long, or 25'. I know which I favour.

 

Glyn

 

PS how many of you can honestly say that when asked how tall you are, or what you weigh, you reply in metric. I'm 6'2" and weigh the wrong side of 15 stone.

[Jivemaster]

On the day that the EU decided on compulsory metric only marking, the US decided on compulsory feet and Inches only marking.

 

Yes I still think in Imperial sometimes (no OFTEN!) some metric mesures still confuse especially when mixed SI MKS and CGS. Newtons I can fathom but Pascals ?????

[Ekij]

My point is that we have two systems and that doesn't appear to be going to go away any time soon.

Therefore people need to present values in both sets of units and be competent to transfer between them intelligently.

Is your 6' = really 1828mm, are you measuring to 1mm accuracy? I very much doubt it. 1830mm (or even "a bit over 1800mm") is probably more like it.

The issue was implied accuracy after doing a conversion. Quoting to 4 significant figures in mm where there was only 1 in feet is wrong.

[Jivemaster]

Imperial will be a necessary system for many years as lots of building and architectural work was designed in imperial and is still in long term use.

[TomLyall]

Yes I still think in Imperial sometimes (no OFTEN!) some metric mesures still confuse especially when mixed SI MKS and CGS. Newtons I can fathom but Pascals ?????

A Pascal is just 1 Nm^-2. It's easier not to use the Pascal, and stick to discribing everything in SI base units. Stick to metres, kilograms, seconds, amperes, kelvins, moles and candelas and you can't go wrong! :(

 

Edit: My bold, deliberate pun?

[Roderick]

I live in a country where it is not unusual to have an 8' x 4' riser at 600mm high - go figure.

My favourite measurement: Furlongs per fortnight.

 

But I support Ekij point, if you need to transfer between imperial and metric, use the closed unit otherwise it doesn't mean much. I'd say: feet to metres, inches to centimetres (or mm if you must :( ), miles to kilometres.

 

And don't touch pints, a pint of Guinness in any other unit would be an insult.