Project Idea: Write a report on the history of measurement systems using books/ internet for reference.
Answers
The earliest recorded systems of weights and measures originate in the 3rd or 4th millennium BC. Even the very earliest civilizations needed measurement for purposes of agriculture, construction, and trade. Early standard units might only have applied to a single community or small region, with every area developing its own standards for lengths, areas, volumes and masses. Often such systems were closely tied to one field of use, so that volume measures used, for example, for dry grains were unrelated to those for liquids, with neither bearing any particular relationship to units of length used for measuring cloth or land. With development of manufacturing technologies, and the growing importance of trade between communities and ultimately across the Earth, standardized weights and measures became critical. Starting in the 18th century, modernized, simplified and uniform systems of weights and measures were developed, with the fundamental units defined by ever more precise methods in the science of metrology. The discovery and application of electricity was one factor motivating the development of standardized internationally applicable units.
Contents
1 Sources of information
2 Earliest known systems
3 History of units
3.1 Units of length
3.2 Units of mass
3.3 Units of time and angle
4 Forerunners of the metric system
5 Metric conversion
6 References
7 Further reading
Sources of information
Weights and measures have taken a great variety of forms over the course of history, from simple informal expectations in barter transactions to elaborate state and supranational systems that integrate measures of many different kinds. Weights and measures from the oldest societies can often be inferred at least in part from archaeological specimens, often preserved in museums.[citation needed] The comparison of the dimensions of buildings with the descriptions of contemporary writers is another source of information. An interesting example of this is the comparison of the dimensions of the Greek Parthenon with the description given by Plutarch from which a fairly accurate idea of the size of the Attic foot is obtained. Because of the comparative volume of artifacts and documentation, we know much more about the state-sanctioned measures of large, advanced societies than we do about those of smaller societies or about the informal measures that often coexisted with official ones throughout history. In some cases, we have only plausible theories and we must sometimes select the interpretation to be given to the evidence.
By studying the evidence given by all available sources, and by correlating the relevant facts, we obtain some idea of the origin and development of the units. We find that they have changed more or less gradually with the passing of time in a complex manner because of a great variety of modifying influences.[citation needed] It is possible to group official measurement systems for large societies into historical systems that are relatively stable over time, including: the Babylonian system, the Egyptian system, the Phileterian system of the Ptolemaic age, the Olympic system of Greece, the Roman system, the British system, and the metric system.