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Tip o' the Week #85  - How Accurate Is Accurate Enough?

Dear [firstname]

I have written before about the reticence of modern archaeology to accept the reality that our prehistoric foremothers and fathers were in to accurately measuring the movements of the Sun, Moon and perhaps the other planets.  Archaeoastronomers like Alexander Thom were at first put down, and then just ignored because their findings didn't fit in the archaeologists' paradigm of those "primitive savages."  And besides, when they went to the ancient sacred sites
with their modern well machined devices (whose massive standing stones and chambered walls certainly must have moved a wee bit in five-thousand years), they found that the ancients weren't accurate enough - they weren't up to modern standards, so they just weren't relating to the heavenly bodies.

The Egyptian Cubit

The Egyptian Cubit

The Egyptian Cubit

This issues of how accurate is accurate enough and what is the best unit of measurement to use have plagued modern scientists and academics as they look back through the pages of history, not to mention prehistory.  The Egyptians used the cubit.  The ruling Pharaoh was considered to be God's manifestation on Earth, so the distance between his/her elbow to the tip of their middle finger was used as the standard measuring unit during their reign.  Of course this length changed with each new Pharaoh, but that didn't actually make any difference because rather than the specific units of measurement that were used, the important thing in the construction of Egyptian sacred space (as it was until the time of Oliver Cromwell) was the ratio within the construction that makes the difference in sacred geometry.  Whether the room is 10 cubits by 20 cubits, or 10 feet by 20 feet, or even 10 meters by 20 meters, the spaces will create the harmonics of a double square.

Roman Accuracy *

The word “mile” comes from the Latin word for “thousand”, from the phrase mille passus, literally “thousand paces”. Each passus consisted of five pes, the Roman foot, so the mille passus was 5,000 pes. This distance was also known as a milliarium, literally “milestone.”  How accurate is that?

Inches and Feet

England, the USA use inches, feet and yards. For an example, an inch was the length of three barleycorns from the middle of the ear, placed end to end, or the width of the thumb at the base of the nail. The "thumb inch" was especially common in the cloth trade until 1711, when Queen Anne explicitly forbade its use.

Both the Imperial units and US customary units derive from earlier English units. Imperial units were mostly used in the British Commonwealth and the former British Empire. US customary units are still the main system of measurement used in the United States despite Congress having legally authorized metric measure on 28 July 1866. Some steps towards US metrication have been made, particularly the redefinition of basic US units to derive exactly from SI units, so that in the US the inch is now defined as 0.0254 m (exactly), and the avoirdupois pound is now defined as 453.59237 g (exactly)

The Metric System - The Ultimate in Accuracy and Consistency? *

The French Revolution
in 1791 brought us the metric system; however, a number of metric systems of units have evolved since the adoption of the original metric system back then. The current international standard metric system has been the result of a number of revisions.  For example, the Kilogram was again redefined in 1870s.  It is a cylindrical lump of platinum and Iridium cast in London in 1879, and then sent to Paris.

The Kilogram
The Kilogram


The international prototype kilogram (IPK).  is made of a platinum-iridium alloy and is nested in three bell Jars and stored in a vault at the International Bureau of Weights and Measures in Sèvres, France.

Unfortunately, when the original was compared with official copies of it, it was found that there was a discrepancy of up to 60 micrograms - slightly less than the weight of a grain of sand.  So on January 24th of this year (2011), it was decided at a meeting of the Royal Society of London to recast it in a material less mercurial than platinum-iridium alloy.  Once again, this system is to be readjusted due to our scientific ability to make more and more accurate instruments and measurements.  Yes, this will impact on our lives.  When one recent Mars flight crashed on landing on the Red Planet, it was discovered that while most of the parts were made using the Metric System; unfortunately, some were constructed using inches and feet.  (Duh!)

In the seventies, there was a movement for Britain to switch to the Metric system, John Michell led the anti-metrification movement. Don't Give an Inch!  To this day, there isn't a complete switch.  We buy petrol or diesel in liters, but drive in miles per hour.

And now science is yet again redetermining the kilogram and probably questioning the length of the millimeter.

So we come back to this question - how close is enough?  How accurate does one have to be to determine truth?

And more important, who gets to decide?  Is being off by the width of a gnat's ass off enough to make a Neolithic solar alignment not close enough?

"The only real valuable thing is intuition."
  - Albert Einstein (The man who gave us
the best known scientific formula of the 20th Century.) 

I think he was on to something.

Sig's sig
Sig Lonegren
9 Bove Town?
Somerset BA6 8JE?
http://www.sunnybankglastonbury.co.uk?+44 (0)1458 835 818

* I want to thank Wikipedia for much of the descriptions of these units of measurement.