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# The History of How Things are Measured

Metrology Parts has released its “The History of How Things are Measured” which is published below.

Measuring the world around us has allowed for trade across continents, the crossing of oceans, the building of cities, and exploration of space. However, in the beginning, basic measurements were arbitrary. Every major civilization added to the collection of knowledge and either built upon or invented new systems of measurement based on their society’s needs. So much so that it is difficult to discuss “The Measurement of Things” without discussing mathematics, science, technology, invention, architecture, medicine, etc., which all have some form of measurement associated with each discipline. Imagining that measurement had to be a human invention seems foreign and in today’s world is largely taken for granted.

In the earliest of times, mankind has needed a method of showing “how much” of something existed. One can imagine early humans coming up with basic methods of deciding how big a spearhead should be or how many hides were needed to cover a cave opening. It is logical to imagine that they used tools that were always with them such as their legs, hands, and feet. As they advanced technologically, the measurement would have become more crucial to the development of commerce and city building that required “standards” of measurement for those civilizations. The history of measurement has seen many forms with early traders having to learn hundreds of standards to ply their wares throughout the known world. As humans developed more accepted standards of critical measurements of weight, length, volume, and time, the world expanded and allowed for the advancement of civilization to what it is today.

Early Concepts – The earliest forms of measurement used the human body as a reference. These included units for length called fingers, hands, cubits, and canes; in modern-day equivalents (approximate) a finger was 2 centimeters (0.8 inches), a hand 10 centimeters (4 inches), a cubit was typically the length of the forearm from the elbow to the tip of the middle finger or approximately 50 centimeters (20 inches), and a cane 1.5 meters (5 feet). While the lengths varied between people and cultures over time, the cubit withstood the test of time and was used in some areas of the world up to the 1960s when it was replaced by the metric system.

Measurements for capacity or volume were equally as important to early civilizations, especially those that had robust commerce systems. The first standards used natural products due to their uniform size and shape. Hebrews and ancient Irish used a hen’s egg; the Chinese used the joints of the bamboo; and gourds may have been used by the Zanzibar, Greeks, and Romans. Other ancient measurements are still in use today including the carat which comes from the carob seed that was thought to have equal weight and even the foot and yard that are still used in the United States and other countries that have not fully adopted the metric system.

It is important to understand that the history of measurement is as convoluted as the history of mankind. Every major civilization recognized that a standardized measure was required for continued advancement. It is easy to believe that humanity had a basis of measurement prior to the Sumerians. They are some of the first civilizations to start keeping accurate records that are still around today.

Sumerians – Around the fourth and early third millennia B.C. the Sumerians, located in modern-day Iran, had developed some of the world’s first cities including large agricultural plots which increased the volume of commerce in the region. To reduce confusion and ease trade, a uniform weights and measures system was developed using a base 60 or sexagesimal numerical system based on astronomical observations. The sexagesimal system is still in use for measuring angles, geographic coordinates, electronic navigation, and time. With the rise and fall of the various empires in Mesopotamia, most of the local administrations (Persians, Greeks, Parthians, Sassanians) adopted a uniform series of weights and measures for ease of administration based on the Sumerian system.

Not only did the Sumerians use standardized measurement for commerce and architecture, but they were also some of the first people to start making accurate observations of the world around them. Astronomical periods such as the solar year, the lunar month, and the seven-day week were identified and measured by Mesopotamian scientists. Using these measurements, these scientists were able to calculate how the world changed based on astronomical observations. They are documented as being able to predict the length of daylight throughout the year and when the moon, planets, and eclipses would happen. Later the Persians would continue to make advancements in mathematics and astronomy.

Indus Valley – Around the same time there is archeological evidence that the largest city of Mohenjo-Daro, located in modern-day Pakistan, excavated uniform bricks (generally using a 4:2:1 ratio for length, width, and height). This ratio was observed to be stable for building brick structures and suggests that civilization had the basic concepts of the need for a measurement standard for construction. Lengths were measured with a degree of accuracy based on a purposely designed ruler that was divided into ten equal parts. Weights based on ratios: 1/20, 1/10, 1/5, 1/2, 1, 2, 5, 10, 20, 50, 100, 200, and 500 were the typical standard with each unit weighing approximately 28 grams. These ratios were used by city authorities to build stable infrastructure and constitute an important part of urbanization.

While scientific advancement was happening in the Indus Valley, it is more known for its superior architecture and urban planning techniques. Mohenjsup had evidence that there was a well-organized social and economic structure planned around a city with healthy sanitation, civic buildings, and infrastructure. Buildings were typically multistoried with separate toilets and kitchens and common purpose buildings such as granaries, warehouses, and baths were located throughout the city. Sanitation included underground drainage systems connecting every building. This mindset shows how important measurement was to developing a technologically advanced civilization.

Egyptians – Observations from Egyptian construction of the pyramids, temples, and tombs make it obvious that their civilization had incorporated a standardized measurement system. Archeological evidence of measuring rods of various materials for length, stone, pottery, and bronze items including grains of wheat for weight, and jars, barrels, and sacks for volume has survived.

Egyptian scientists produced significant advances in astronomy, mathematics, and medicine partially based on their measurement systems. Using geometry, farmland was surveyed and proper ownership established that allowed for flooding to produce crops. Egyptian science has strong parallels with the basic empirical method of experimentation and measuring observations. Medically, these observations were written in some of the first medical documents produced.

While the abstract concept of time was not new, the Egyptians invented one of the earliest sundials to divide the day into equal parts. There is no clear understanding of why the clock was divided into twelve equal parts but it could stem from the sexagesimal system used by the Sumerians. Understanding time was important to the astronomers and priests to measure the exact hour when solar events happened and when daily rituals were to take place.

Greeks – During the Hellenistic age, Greek and Egyptian cultures conducted commerce together along with other cultures in the Mediterranean region. Parts of the Egyptian measurement systems were adapted all along the trade routes of the Mediterranean Sea. However, at times the same word could have different meanings depending on location, which in turn could lead to confusion.

Before the Greeks decided that there was a need for the hours of the day to have a fixed length, the ancient world divided the days and nights into twelve hours each. This system would create inaccuracies due to the planet tilting on its axis and cause longer days and shorter nights depending on the year. The idea of using a 24-hour cycle was proposed by Hipparchus and is known as equinoctial hours which would require much more accurate measurements of time.

Europe – During what is known as the Dark Ages much of the world’s advancement in technology and science (and therefore measurement) had slowed down significantly. Northern Europe had historical evidence of measurement standards which were primarily derivatives of the Greek and Roman systems brought to the area by conquest. It wasn’t till after the thirteenth century that advancements in measurement took place when King Edward I of England decreed the first “yardstick” which, like the cubit, was based on the length of the forearm. He had an iron rod made which was graduated into one-third lengths called a foot and each foot graduated into twelve inches. Each inch was decreed to be the size of, “three barleycorns, round and dry” by King Edward II who reverted to the ancient way of using known items for standards. This is the basis of the English System which a good portion of the world used prior to the adaptation of the metric system.

In the early seventeen hundreds, France had measurements based on the size of a loaf of bread, which proved to be inconsistent across the realm, causing unrest with the people. This led to the adaptation of a new system by Napoleon in 1793, with standards based on the meter which was reported to be one ten-millionth of the distance around the equator. The meter and its subsequent base ten units, kilometers, centimeters, and millimeters was the standard with the volume being linked to the size of a base ten-sided cube called a liter and weights were in grams. This new system was called the metric system but was short lived due to the country being used to the older English System of measurement and was eventually dropped until 1837 when it was again adopted and found support in the scientific community, where it was dubbed the SI Metric System. This support became worldwide with only a few countries not officially adopting the standard.

While France and England were developing their standards, scientists of the day were discovering new ways to observe and measure the world around them. Great scientists of the time had discovered gravity, radiation, bacteria, germs, electricity, and a great deal more within the “renaissance” period. Each new discipline would require new ways to measure the physical traits of each new advancement in science and medicine. Many times, instruments were invented to be able to measure what was theorized to exist in a new world that was more “unseen” than ever before.

Present Day – Today everything in the world is measured; from the smallest quantum particles that make up all matter to the speed of universal expansion. New advances in technology and computing power have contributed to new measuring techniques, equipment, and terminology used in disciplines that did not previously exist. With the invention of the computer, databases of measurements can be compared and processed to find trends to predict the future with speed and accuracy. The exponential speed of technological advances that are seen points to a future that is almost unimaginable. Every person has a measuring tape in his or her toolbox and every company relies daily on accurate measurements in order to achieve maximum profits. With the abundance of measurement data being collected and used, world leaders have been striving to have a world standard for all measurements to increase scientific development, commerce, cross-border manufacturing, etc. The International Bureau of Weights and Measures maintains the world database of all measurement standards and has identified nine key areas: acoustics, electricity and magnetism, mass, length, photometry and radiometry, ionizing radiations, time, and frequency, thermometry, and chemistry.

Manufacturing to meet the needs of today’s consumerism requires heavy use of automated machines that require calibration and programming. These machines can measure their programmed parameters with very precise tolerances and have strict quality control. For things like pharmaceuticals, aircraft components, microchips, surgical equipment, etc., the accuracy and precision of component parts are critical to comply with operational tolerances, safety, and quality.

Advances in the medical field have required increased precision of physiological, biochemical, physical, and other variable measurements to facilitate proper treatment of patients, research, and new technological development. It is important for researchers and scientists to start with the same standards for terms and units of measurement to have a clear understanding and communication. As medical measurement becomes more precise, the human eye is no longer a reliable instrument requiring critical measurements to utilize other technologies such as optical techniques, sound, radiation, etc. Conducting non-invasive procedures for diagnosis and treatment utilizing MRIs, Cat Scanners, and other medical devices allows better decisions to be made for the care and treatment of patients.

The Future – Measurement tools of the future will not only measure critical attributes but will be expanded to include a more complete picture. Advancements into three-dimensional measurements using optical technologies will automate changes as they are found. As devices become more complex and miniaturized, accurate tolerances are crucial. This is especially true for the medical field that is showing significant advancements in diagnostic tools to nanomedicine. The reliance on increasingly sophisticated tools and techniques is critical for the quality control that is needed in the new world.

The future of measurement will continue to change as mankind’s perception of the environment changes. The future promises space exploration, advanced medicine, quantum mechanics, process automation, environmental protection, and areas that are not even understood. As the world grows, much like our ancestors, humanity will continue to develop new and more precise ways to measure things that are discovered to advance our civilizations.