English/metric measurement error in the Mars Climate Orbiter

[Toolmaker51]

Where then do we quench our thirst for lowly but almighty zero's?

[MeJasonT]

Yep I agree - both
its worked brilliantly for me over the last 20907248182351.028089724211549023 Kmh or 48 years if you want to be technical.
I often measure steel with mixed metric and imperial measurements sometime its easier to see an exact mark at 4 inch's than give an approximate mm measurement.
I do think the American system has more merit than the old English measurements like Whitworth etc. Perhaps where we are getting it wrong is trying to standardise. Old aircraft flew and new ones fail due to errors ? Just ignore that small section of aviation history where the comets kept falling out of the sky - funny they still do, the RAF has lost a few in the last 20 years. (otherwise known as Nimrod or comet mk4).

https://en.wikipedia.org/wiki/De_Havilland_Comet

And these are the brand new ones we scrapped with zero hours on the clock (there you go toolmaker a zero for you).
https://www.theregister.co.uk/2011/0...rod_scrappage/

[Drew1966]

Yep I agree - both
its worked brilliantly for me over the last 20907248182351.028089724211549023 Kmh or 48 years if you want to be technical.
I often measure steel with mixed metric and imperial measurements sometime its easier to see an exact mark at 4 inch's than give an approximate mm measurement.
I do think the American system has more merit than the old English measurements like Whitworth etc. Perhaps where we are getting it wrong is trying to standardise. Old aircraft flew and new ones fail due to errors ? Just ignore that small section of aviation history where the comets kept falling out of the sky - funny they still do, the RAF has lost a few in the last 20 years. (otherwise known as Nimrod or comet mk4).

https://en.wikipedia.org/wiki/De_Havilland_Comet

And these are the brand new ones we scrapped with zero hours on the clock (there you go toolmaker a zero for you).
https://www.theregister.co.uk/2011/0...rod_scrappage/

I assume from this that you have only looked at distances in American Imperial measures. The liquid volumes are about 20% smaller than the English equivalents. This all goes back to the American Pint being 16 ounces and the original English pint being 20 ounces. It really would be simpler if everyone used the Metric system. Powers of ten for multipliers.

[tonyfoale]

It really would be simpler if everyone used the Metric system. Powers of ten for multipliers.

Then we would not be able to use those lovely rods, poles and perches. We would have to keep chains of course, how else could you lay out a cricket pitch? One could not expect the MCC to go metric, just not cricket old boy.
I was always aware of the time spent (wasted) on learning £ s p arithmetic in school. At least the Americans have had the good sense to always use decimal currency, so it seems strange that most are resistant to the idea of decimal measurements in general.
Apart from the decimal nature of the ISO metric system the thing that I like the best is the consistency of the units. If you forget what certain derived units are you only have to use the base units of kg, m and sec to get reminded.

What is a newton - we know it is a force and as F=ma a N must be kg.m/sec^2
What is a joule - it is work so it has to be force x distance which is Nm. So 1 joule = 1 Nm
What is a watt - it is power so it has to be work/time which is joule/sec or Nm/sec So 1 watt = 1 joule/sec = 1 Nm/sec
What is a pascal - it is pressure so it has to be force/area which is N/m^2 So 1 pascal = 1 N/m^2

That is as simple as it gets. This consistency of the units reduces the chance of errors greatly.
Do not just think of the ISO metric system as being only a decimal system, it goes much further than that.

[mklotz]

Apart from the decimal nature of the ISO metric system the thing that I like the best is the consistency of the units. If you forget what certain derived units are you only have to use the base units of kg, m and sec to get reminded.

What is a newton - we know it is a force and as F=ma a N must be kg.m/sec^2
What is a joule - it is work so it has to be force x distance which is Nm. So 1 joule = 1 Nm
What is a watt - it is power so it has to be work/time which is joule/sec or Nm/sec So 1 watt = 1 joule/sec = 1 Nm/sec
What is a pascal - it is pressure so it has to be force/area which is N/m^2 So 1 pascal = 1 N/m^2

That is as simple as it gets. This consistency of the units reduces the chance of errors greatly.

While the inferial system has such idiocies as "fluid-ounce" which is a measure of volume, not weight.

Do not just think of the ISO metric system as being only a decimal system, it goes much further than that.

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

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

[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.

[MeJasonT]

It gets worse we we trust computers which are really bad at math. And yet the disasters are not just for home users.
https://www.theregister.co.uk/2019/0...ndows_crashes/

Sort of off topic but still on if you get my drift is this artical i came across on the same search for comet info

https://www.theregister.co.uk/2018/1...ghty_language/

Have i read this correctly googles filtering server searched its own database and shut itself down ?
Are they getting fed up of our searches containing f-ing google this that or the other when their service is less than perfect.

We have gone full circle to the early space crashes that involved the dreaded missing jump returns in code leading to code stalling and the inevitable crash.

When are programmers going to stop being narcissists and admit they are not perfect.
we will all suffer the day they remove the OFF switch.

[Tonyg]

It gets worse we we trust computers which are really bad at math. And yet the disasters are not just for home users.
https://www.theregister.co.uk/2019/0...ndows_crashes/

Computers are rarely bad at mathematical computations, however, programmers often are.

[MeJasonT]

A rant about PC reliability.

Its a shame that they are only able to do addition and subtraction to achieve complex computations and are truncated by there limited word length of bits, as for random numbers even using monte carlo is realistically beyond the capability of a PC to truly generate a random number. The fact they are cyclic is also hindrance.
And yet we argue the far end of a fart that computers are reliable and the operators/programmers are to blame. Programmers are to blame, they are trying to convince us we need to have our every whim catered for by machines. If you build something really reliable and it makes loads of money upgrade it to a new one so the old reliable one becomes obsolete so you can sell an unfinished glitchy unreliable one.
Its a pain in the bum hole that our governments have decided our whole life will be online to acquire benefits, pay bills, apply for licences etc and yet the reliability of the whole infrastructure is questionable at best.

[MeJasonT]

I have now got to a point in life where i have decided to have the attitude of whatever floats the boat, 4oz such an insignificant figure.