Difference between revisions of "Mars Metrology"
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Introduction
Metrology is the term used to describe the science of measurement. Although scientific methods are used in achieving prescribed levels of precision for the various units of measurement, the methods used in defining various units are often based upon long standing cultural factors. The subject is not without controversy, which can be seen in the traditional Wikipedia - Metrology entry.
The base units, a "time unit", a "length unit", a "weight unit", are defined to fit the requirements of the Martian environment, and are structured to avoid the conflicts of commercial versus scientific usage. The essential difference between the Earth defined system of measurement is that Mars Metrology provides for a distinctly different set of base units for scientific uses as opposed to those that accommodate commercial uses. When a base unit or derived unit are the same value for both commercial and scientific use this will be noted.
The commercial base units provide values which readily accommodate human interactions between individuals and within the environment specific to Mars. These units need not be based upon a physical science or mathematical constant, but is always desirable to do so when possible.
Scientific units are defined using physical science and mathematical constants such that all the derived units have a direct mathematical relationship to the base units as opposed to the current defined relationships.
Historical development
The basic history of metrology needs to be examined to identify the various areas of contention that has accrued over time. There are very few things in science that haven't been politicized in one way or another and metrology has been heavily influenced by various factions. There is no need to replicate what has been written in the Wikipedia - metrology pages. In the U.S. the descriptions of the various base units and constants are provided at - National Institute of Standards and Technology (NIST).
Most of the various SI base units of measure were defined as stand-alone values, at least that is claimed. The following quote is from the NIST units page. "The SI is founded on seven SI base units for seven base quantities assumed to be mutually independent, ..." It is obvious on its face that this statement is false, as the definition of the meter is clock-dependent, as noted by the defintion for the NIST unit of length. The NIST site does not state where the value 1/299 792 458 of a second comes from, but we know it is the previously measured value for the speed of light in meters and seconds. The Swiss Office of Metrology provide a more meaningful description of the - metre.
There are a number of organizations that exist to monitor and make recommendations on how units and constants are to be defined. A committee associated with the International Union of Pure and Applied Physics (IUPAP) issued a report that stated, "the consensus that now exists on the desirability of finding ways of defining all of the base units of the SI in terms of fundamental physical constants so that they are universal, permanent and invariant in time; - IUPAP.
The duration of the "time unit" defined as the second was determined by astronomers using ephemeris time. The origin of the "ephemeris second" is discussed in the article titled, The Science of Timekeeping. It took them three years to decide that 9 192 631 770 periods of the Cesium-133 transitions would be the official "atomic" duration for the second. The duration of the ephemeris second was determined in 1954 and the "atomic" duration is based upon 1964 technology. The precision of the "second" is limited to 10 significant figures. The precision of the value for the meter is limited by the defined value for the speed of light. All scientific constants defined using the meter are limited in precision even though the meter is assigned a value of "one" in the calculations.
Commercial interests have a need to define units using tangible things that can be felt and seen. There are characteristics in nature and mathematics that are vastly more accurate and stable than tangible objects.
Commercial units
This section needs to be developed
