(I know this page is VERY pedantic)

Why do people put up with illogical notations?

Every day I hit incomprehensibly stupid notation, sometimes making communication difficult.  Here are a few examples.

Imperial measures

You know the classical intelligence tests where you have to find the next in a sequence.  Example:  given 2,4,6,8,10, what is the next number?  12 is an obvious choice because the numbers in the series increase by 2.

What about this sequence:

3, 16, 7, 32, 1, 4

What is the next number?  It's obviously 9!  Why?  Look at a small socket wrench set for nuts in Imperial measures:  the sockets are labelled in fractions of an inch.  In the set I own the smallest one is for 6/32", then 7/32", 8/32", 9/32" and so on.  But the fractions are reduced, so the actual labels are:

3/16  7/32  1/4  9/32  5/16  11/32  3/8  7/16  1/2

Hence the weird sequence of numbers in the "test" above.  Great…

Off the top of your head, what's the size just greater than 11/32"?  3/8" must spring to mind immediately…

At least my metric set of sockets goes:  6 mm, 7 mm, 8 mm, … all the way to 23 mm after which it goes in steps of 2 mm.

There are other numbers in the imperial system that must be very difficult to remember and use:  how many yards in a mile?  How many cubic inch in a cubic foot?  How many fluid ounces in a cubic inch?

Fortunately it should at least no longer depend on which side of the Atlantic you are on now the UK is metric and the USA is the only remaining country using the imperial units.

I have some evidence that the imperial units could not be used for precision engineering.  I was given a micrometer that belonged to a friend of mine who passed away recently.  He was educated in the UK before metrication.  The device he owned and that is now in my care looks like this:

It can measure up to one inch.  But the division is into 1/1000 of an inch (25/1000 per turn).

The strange thing about it is the table engraved on the bottom of the frame:

Presumably measuring and calculations were done using the decimal system and the decimal division of the inch.  The table on the brace then served to "convert" back into the more classical imperial way of expressing measurements in fractions:  e.g. 0.4687 inch corresponds to 15/32".

Time & Date

Anyone who has struggled with lists of dates in a computer will know the frustrations that come with passing such lists from one application to another.  There are just too many different and often strange ways to note dates and times.  The ISO standard, used in Scandinavia and increasingly in other countries, is:


I wrote these words at the time 2004-06-05  21:38:57.

The YYYY-MM-DD HH:MM:SS notation is also recommended for the Internet by the W3 Consortium and others.  The advantages of this notation are many:

Ambiguities can be very annoying.  what date is 06/05/04?  It can be anything, especially if you also allow the US interpretation where the numbers are not even in order of significance.  And is 12 p.m. 00:00 or is it 12:00?  Or is that 12 a.m.?


Hah!  The seventeenth century… that was the 1600's.  Just because we did not start numbering years at zero.

If you are counting, start with one and you will have the number of items you are counting.  If you are measuring, start at zero or you will not have the size of the thing you are measuring.  Compare:

a ruler:  starts at 0, the marks are numbered


a calendar:  the years are between the marks.


The mark between the items on a calendar represents an instant in time, with no duration, just like the mark on a ruler ideally has no dimension.  But we should still have numbered the first year "zero" and the first century "0" so that it would have been less confusing to subtract dates.  And then the new millennium would really have started in 2000.

Base twenty

Counting in French is probably one of the most difficult things that non-French speakers have to learn when they study the "langue de Molière".  For the number 99 you have to say "quatre-vingt dix-neuf" because things were at some point counted in groups of twenty.  Twenty was also used in English:  Abraham Lincoln's famous Gettysburg Address starts with the words "Four score and seven years ago …" meaning 87 years, 4x20+7.

But why still stick to such inefficient language now?   The French-speaking Swiss are quite ahead:  they use the terms soixante, septante, huitante, nonante for 60, 70, 80 and 90 respectively rather than the "official French" terms of soixante, soixante-dix, quatre-vingt, quatre-vingt-dix.

"organisons plus pour travailler moins".

Valid XHTML 1.0 StrictValid CSS

next planned revision: 2006-11-30