English/metric measurement error in the Mars Climate Orbiter

[olderdan]

For those not sure why we would bother to measure insects in chains.

Cricket, explained
You have 2 sides, 1 out in the field; and 1 in.
Each man that’s in the in side, goes out, until he’s out and then he comes in, and the next man goes in until he’s out.
When the in side have all gone in and out, the side that was out comes in, and the side that’s been in and got out, goes out and tries to the side coming in, out.
Sometimes you even get a man still in, and not out.
When both sides have been in and out, including the not outs, that’s the end of the game

That is amusing and just about sums up my understanding of the game of cricket but then I have never been interested in any sport that is just based on a ball.
However the scene of cricket played on a village green on a summer afternoon is a pleasing sight, so british don't you know.

[mklotz]

Robin Williams had a more compact definition of the sport, "Cricket is baseball on valium." Considering that baseball is highly compacted tedium, that's quite an insult.

[Frank S]

Robin Williams had a more compact definition of the sport, "Cricket is baseball on valium." Considering that baseball is highly compacted tedium, that's quite an insult.

I don't know about cricket being baseball on valium, I've been to a lot of professional baseball games and I found that the only reason the huge pipe organ plays so loudly is to keep you awake while the catcher plays finger talk and the pitcher has to stare as the guys junk and nod or shake his head.

[Hans Pearson]

I have a Rabone tape measure that has 10 inches to the standard foot, the individual inch is also divided into 10 divisions. I cannot find any reference to this measuring system

[hemmjo]

If it is really 10 divisions per actual foot, it is an engineer or surveyors tape.


I was outside on my phone for the first part of this.

The tape you have is not graduated in feet and inches, it in feet, tenths and hundredths of feet.

In the photo of my two survey sticks, you can see which one has had the most use,

4 ft 7 3/8 inch = 4.61 ft (read the top of the red line)

[Hans Pearson]

Thank you for that information. It was actually passed down to me from an engineering-based person who had owned a sheet metal works.

[tonyfoale]

Thank you for that information. It was actually passed down to me from an engineering-based person who had owned a sheet metal works.

It is a big mistake to attempt to see anything reasonable in the imperial system or its offshoots. That comes from someone brought up on the system. My advice is to burn all rulers not graduated in mm.

[mklotz]

It is a big mistake to attempt to see anything reasonable in the imperial system or its offshoots. That comes from someone brought up on the system. My advice is to burn all rulers not graduated in mm.

Good advice, Tony.

One of my favorite examples of the idiocy of the inferial* system is having a volume unit depend on what is contained in said volume...

There are seven different barrel sizes used in the USA, with the size being dependent on the contents. Their names and metric equivalents are as follows: US cranberry (95.5 liters), US dry (115.628 liters), US liquid (119.24 liters), US federal (117.348 liters), US federal proof spirits (151.416 liters), US drum (208.4 liters), US petroleum (135 kg.), US petroleum statistical (158.99 liters)

-------
* my term for the further botched version of the Imperial system used in the USA under the name "US Customary Units". "Inferial" is a portmanteau of "inferior/infuriating" and "Imperial".

[tonyfoale]

Good advice, Tony.

One of my favorite examples of the idiocy of the inferial* system is having a volume unit depend on what is contained in said volume....

It is not only the idiocy of the units system that causes confusion and problems. Possibly the source of more mistakes is the misuse of the units that are there. The infernal system does have well defined and consistent units (maybe not in everything) but very few people use them or use them correctly. One VERY common misuse is with mass and weight.
The ISO system has kg for mass and Newtons for force. We all know that F=ma, so 1 kg accelerated at 1 m/s2 requires a force of 1 N. Simple and mistake proof. Nobody in a technical environment gets this wrong. Supermarkets are unlikely to weigh things in Newtons, they use kgf which they call kg. but this is unlikely to make a bridge fall down.
On the other hand it is common in imperial land to use lb for mass and lbf for force. The problem here is that F != ma it should become F = ma/g. Looked at in another way you have to express the acceleration in Gs not ft/sec2. I have had countless people ask me "I know that I have to insert "g" but does it go on the top line or the bottom". When using lbs for mass and ft/sec2 for acceleration the correct unit of force is NOT lbf but poundals pdl (or maybe PDL, I try to forget). If you insist on using lbf for force then there is another unit of mass called the slug which is lbf x g or numerically a slug is 32.2 times a lb. The slug is common in the imperial aircraft industry.
I have been told that the Mars error was due more to this F = ma or is it F = ma/g then again perhaps it might be F = mag, than just a simple case of using metric or infernal.
One of the things that really get me steaming is when I see imperial engineering profs. and the like talking about weight density. What type of evil is that? It is unbelievably crazy, confusing and mistake prone. The worse thing is that these utterances are from technical people brought up in that crazy units system. They more than anybody should use it correctly.

[hemmjo]

I know we are not supposed to talk politics here, but I do think this is bit relevant to the Metric vs Imperial system. Jon, if you wish to delete this, I will not be offended.

We are in this metric vs imperial situation all due to politicians. https://www.thefactsite.com/imperial-metric-facts/

I simply live my life, use what tools I have to do what I need to do. I am comfortable using either system. To me they are simply a different language. I was raised speaking English. I also know a little, very little, Spanish, French and Haitian Creole from some mission work I have done in the past. Neither of those is wrong, just different andI know one A LOT better than the other three.

I can measure in both and have both to measure with. I have a great number of precision measuring tools that belonged to my father. Some from the 1930's. I learned a lot from him and miss him a lot. Someone suggesting that I throw them out, even if I do respect the person, is not going to sit well with me.

Let's all use the system we are comfortable with and not criticize. Nothing we say here is going to change the fact there is more than one measuring system.