English/metric measurement error in the Mars Climate Orbiter

**owen moore** · Feb 24, 2018, 09:05 PM

This reminds me of the astronaut who missed the earth by a million miles during re entry and said "damn that decimal point!"

**Mi Tasol** · Feb 25, 2018, 03:49 AM

Originally Posted by owen moore

This reminds me of the astronaut who missed the earth by a million miles during re entry and said "damn that decimal point!"

I guess you are quoting the poor dummy driving Tesla's electric car

**Philip Davies** · Feb 25, 2018, 06:16 AM

I first learned of this disaster when reading John Neal’s book on metrology, “All Done With Mirrors”. In this, he shows how the English foot is an integrated system of great antiquity, which system is a more accurate fraction of the polar axis than the meter, which unfortunately was calculated without taking into account the fact that the Earth is an oblate sphere . ( I do not subscribe to the notion that the Earth is flat and has 4 corners, although I know people who believe this!) Oh, I am also a graduate of the University of Wales, where I learned to respect opinions for what they are.

**mklotz** · Feb 25, 2018, 08:22 AM

Originally Posted by Philip Davies

I first learned of this disaster when reading John Neal’s book on metrology, “All Done With Mirrors”. In this, he shows how the English foot is an integrated system of great antiquity, which system is a more accurate fraction of the polar axis than the meter, which unfortunately was calculated without taking into account the fact that the Earth is an oblate sphere . ( I do not subscribe to the notion that the Earth is flat and has 4 corners, although I know people who believe this!) Oh, I am also a graduate of the University of Wales, where I learned to respect opinions for what they are.

Talking about the "accuracy" of the standard of a measurement system is pure, absolute nonsense!

I suggest you read the following discussion...

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

in particular, this paragraph...

Some folks want to argue that the metric system is flawed because the length standard it uses is "wrong". The French set out to make the meter one ten-millionth of the distance from the Earth's equator to the North Pole. Their technique for measuring this quantity was inspired and they did an admirable job considering the tools available to them at the time. Still, the value they obtained was very slightly in error. But, NONE OF THIS MATTERS IN THE LEAST. All measurement systems are based on a choice of some arbitrary standard. Whether it's the length of the King's arms or the distance traveled by light in a vacuum in a given period of time, it's the fact that everyone agrees to use that length that's important and the real test of a measurement system is how well it satisfies the criteria outlined at the beginning of this text. THE NOTION OF "ACCURACY" OF A MEASUREMENT SYSTEM IS COMPLETE NONSENSE. Accuracy is a function of the measurement tools and techniques, not the system in which the measurements are expressed.

**Philip Davies** · Feb 25, 2018, 12:45 PM

Perhaps it would have been better had I written “which VALUE is part of a system of immense antiquity” (compared to the VALUE of the metre, which as you say, is very slightly in error - partly owing to the oblate sphere of the earth) I had already read your post and I have also read his book and discussed this topic with Neal. My intention, if you read carefully what I have written, is merely to introduce to this forum a well-researched publication on metrology, not to debate whether one system is better than another. Mechain and Delambre (surveyors, 1793) were attempting to find an accurate value of the meridian, a fraction of which would be the basis for the Metric system. The advantage of the polar axis, if it could be accurately determined, is that it is fixed, whereas the meridian varies: that is the point made by the author.

**NortonDommi** · Feb 26, 2018, 02:12 PM

Here's something of interest, Metrickery near the bottom for those that aren't interested in history or how we arrived where we are.
I look forward to your dissection mklotz.

Weights, Measures and Volumes of the Ancient Mediterranean

**Frank S** · Feb 26, 2018, 09:50 PM

Now that was a long read
Thanks for the eye strain headache LOL

**Philip Davies** · Feb 27, 2018, 01:11 AM

Thank you for this reference, which is very intriguing. It will take a long time to absorb this new information, but I am most grateful.

**Philip Davies** · Feb 27, 2018, 11:29 AM

Now then, Norton, I have begun to study this very interesting article, but oh dear, I have read of a number of astonishing “facts”, which, while plausible, must be regarded as hypotheses, and not likely to be accepted by any academic in the relevant fields. Just thought I’d get that in before someone else does!

**NortonDommi** · Mar 3, 2018, 10:32 PM

Hello Phillip,
Until we invent time travel I doubt if we will ever know the true 'facts' about ancient history but it is a 'fact' that most of what we do know is theory and therefore subject to change when new discoveries are made. I am not an archaeologist but the author of the article is a very well rounded amateur with over 40 years of research under his belt. He is also in regular contact with others around the world many of them academics employed in universities and museums and he runs his theories by numerous people to find flaws. To date those that refute some of his claims have yet to file any evidence whatsoever to negate his research.
With that in mind I can say that not only that article but many other things point to a common umbrella system that was used by all with regional variations. It seems every week there is a new discovery made regarding our ancestors. Satellite imaging in particular is identifying precise places to investigate at an astounding rate.
In this perennial debate about which is best, Imperial or Metric I think it is a good idea to be aware of some history and are reminded of some T.V. programs I have watched where 'scientists' are trying to figure out why something was built a certain way,(measurement wise), and not succeeding because they insist on using Metric.
Sometimes our reasoning can be too rigid for our own good. If something does not 'look right' it usually isn't. I fix a lot of odd things and some are old and it continually amazes me that people try and use Metric fittings on Imperial machinery and visa versa. The Metric system is not perfect and has many traps for the unwary as does the Imperial system. I think the best we can do is be aware of the fact that there has been and continues to be a number of different systems in use and it is upon us to figure out what is what before diving in.