English/metric measurement error in the Mars Climate Orbiter

[tonyfoale]

For more on that, folks can visit my essay...

http://www.homemadetools.net/forum/g...1486#post93973

Marv,

I do not recall reading that previously but I see that I posted a comment there so I must have seen it.
That echos my thoughts exactly. Everyone here should read it.
I grew up with imperial measurements and non decimal currency. I had to wait for a change to decimal currency, that was decided by higher powers but once I left formal education I became a metric convert. That is the ISO metric system, metric land was not always so clear with different base units being used in different fields presumably dictated by the size of the things being measured. For example c,g,s and m,k,s systems. I have seen recent papers still using the c,g,s even a mixture of c,g,s and m,k,s - confusion guaranteed.

PS. A note for those unfamiliar with non-decimal British currency.
Instead of a large base unit like the $ and two decimal places to cater for smaller amounts, the British and Australian system had three units of currency.
Viz: Pounds (£), shillings (s) and pence(d). Yes pence was "d", "p" took over only when the UK went decimal. In addition pence was further divided to get the halfpence (often pronounced happ'ny) and the farthing.
The three units of money is not necessarily a problem, the problem (maybe stupidity is better) was the relationship between them
4 farthings to a penny
2 halfpence to a penny
12 pennies to a shilling
20 shillings to a pound

A totally disproportionate amount of time in arithmetic classes was spent on teaching currency addition, subtraction, multiplication and division.
Imagine ordering 37 milling cutters at £5 3s 8d ea. How long will it take you to calculate the total?
OK let's try to make it easier, surely 10 off instead of 37 is easier? Think so, try it.

[Tonyg]

Just to add to the confusion ( 10 off milling cutters at £5 3s 8d ea) 49guineas 7s 8d

[mklotz]

Let's not forget:

Crown (5/-)
Half Crown (2/6d)
Florin (2/-)
Sixpence (6d)
Silver threepence (3d)

My ex and I visited England in the days before decimalization. She insisted on dragging me to the high-end stores where everything was priced in guineas. I had to ask one of the locals what a guinea was. He told me and I commented that I had never seen one of the bills. "Oh, they stopped minting them before Victoria was crowned" (1837). My first introduction to English monetary confusion.

At first, I carefully checked my change every time I bought something. That required learning about crowns and half crowns, other puzzling denominations. I noticed that the change was often wrong. At first I thought they were just cheating foreigners but at least half the time the error was in my favor so I decided I wasn't the only person confused by such an idiotic money system; the natives were just as confused.

The 'd' for penny derives from the Latin "denarius", a silver coin of the Roman empire used by the English after the Roman occupation. It was simpler to weigh coins than count them and 240 denarius weighed a pound, 'libra' in Latin from which the '£' symbol derives.

[tonyfoale]

Just to add to the confusion ( 10 off milling cutters at £5 3s 8d ea) 49guineas 7s 8d

A gentleman would never mix guineas with s and d. A buyer of milling cutters would never use guineas. Please know your place in the class structure.

[tonyfoale]

Let's not forget:

Crown (5/-)
Half Crown (2/6d)
Florin (2/-)
Sixpence (6d)
Silver threepence (3d)

Crowns and Florins existed but were only in common use way back.

Threepence, you can do better than that - thruppence please.

[MeJasonT]

I don't have a clue what any of you are on about as i was a baby and didn't require coinage - felt almost regal not having to carry cash and have my servants pay for everything (otherwise known as parents). Oh happy days.

I now pay approximately 50% of my income to a bunch of bafoons in taxes

[drum365]

And then we've got pennies,* long tons, statute miles, nautical miles, swimming miles,** stone,*** rods, leagues, pecks, bushels, hands, blocks,**** shots, jiggers, ponies, drams, board feet, acre feet, cords, and RCHs.*****

And don't get me started on Whitworth nuts & bolts!

* nail sizes
** 1650 yards
*** yes, the plural of "stone" is "stone"
**** as a city distance
***** the smallest distance you can move a rip fence by tapping

[MeJasonT]

don't forget sheafs and bushels

some sad person has to look up on wiki leaks what we are missing from our obscure list, i am that person
https://en.wikipedia.org/wiki/List_o...of_measurement

Its also nice to see the lack of dementia amongst us all

[olderdan]

And then there were Gold Sovereigns, how could I forget those I had seven of them once handed down three generations. My X sold them behind my back.
On a lighter note I once overheard my two boys refer to me as Wallet.

[mklotz]

And then there are chains. An acre (the amount of land a man can plow in a day) is a chain wide and ten chains long. A chain is 66 feet long, a tenth of a furlong.

But wait, chains are composed of links. Some demented individual had heard of decimalization but didn't quite get the concept so he divided the chain into 100 links. This makes the link a super convenient 7.92 inches. Considering that math education back in that day was even worse than it is today, one would think they would have gone for something more integerial like say 66 links.