Dear John,

I quote from your article that you sent to Paul Rittman:
My Canadian citizenship card shows my height as 178 cm.  This could also be 
stated as 1.78 m, which is how citizens of mainland Europe would describe their 
height.  Either way, it can be orally  expressed as 'one-seventy-eight'.  If 
the listener thinks in metres rather than centimetres, the decimal point is 
implicit – we do this anyway in other areas, such as when looking at prices in, 
say, supermarkets: “Which brand of pork pie do you want, dear – the shop's own 
at one-ninety-nine, or the national brand at two-forty-three?”  'Dear' knows 
without explanation you mean £1.99, not £199.00.  Notwithstanding Pat 
Naughtin's comments to the contrary, I think if we tried to use millimetres in 
expressing our height to each other, that would kill metric in every day usage 
right from the start.  Sad, maybe – but likely true.

I would like to correct you on one point. I have never advocated the use of 
millimetres for human height. Truth to tell I have mulled over human height and 
its best expression for many years.

I recommend that we use metres with two decimal places where the second decimal 
place is rounded up to the next 0 or to the next 5.

For example. I just measured my height as 1.83 metres. I would record this as 
1.85 metres. The time is currently 17:30 in Geelong.

As you know the centimetre is not sufficiently accurate for measuring human 
height because we vary too much throughout each day. When we wake in the 
morning -- and before we rise out of bed -- we are at our maximum height 
(length in this case). During the day we will shrink as the disks in our 
backbone and other joints lose moisture and become compressed. This amount of 
compression varies from person to person but I have seen it recorded in a range 
from 8 millimetres to 38 millimetres with a mean of 23 millimetres. Because of 
this variability I cannot recommend centimetres for measuring and recording 
human height and similarly I cannot recommend that you record human height 
using millimetres.

By the way height in metres to two decimals is the way that the medical 
community in Australia measures and records human height. No doubt this makes 
it easy for them to then calculate things like Body Mass Index (BMI) and Body 
Surface Area (BSA).

Cheers,

Pat Naughtin LCAMS
Author of the ebook, Metrication Leaders Guide, see 
http://metricationmatters.com/MetricationLeadersGuideInfo.html
Hear Pat speak at: http://www.youtube.com/watch?v=_lshRAPvPZY 
PO Box 305 Belmont 3216,
Geelong, Australia
Phone: 61 3 5241 2008

Metric system consultant, writer, and speaker, Pat Naughtin, has helped 
thousands of people and hundreds of companies upgrade to the modern metric 
system smoothly, quickly, and so economically that they now save thousands each 
year when buying, processing, or selling for their businesses. Pat provides 
services and resources for many different trades, crafts, and professions for 
commercial, industrial and government metrication leaders in Asia, Europe, and 
in the USA. Pat's clients include the Australian Government, Google, NASA, 
NIST, and the metric associations of Canada, the UK, and the USA. See 
http://www.metricationmatters.com for more metrication information, contact Pat 
at [email protected] or to get the free 'Metrication matters' 
newsletter go to: http://www.metricationmatters.com/newsletter to subscribe.

Reply via email to