Reference guides as a teaching and learning strategy: SI Prefixes

Reference guides as a teaching and learning strategy: SI Prefixes

Patrick Blessinger?

Science is an inherently dynamic field of inquiry. As we learn more about the natural environment, we continually refine the scientific knowledge base. This is how science works—a process of continually refining our understanding of the universe through rigorous scientific exploration, experimentation, and theorizing.

As such, over the past few centuries, the scientific community has evolved to the point where a system of measurement with universally accepted dimensions, units, and scales has become necessary.

Standardizing measurement units that describe length, mass, and time changed how scientific inquiry was approached. In giving physical measurements uniformity and specificity similar to what math does with numbers and operations, the SI system allowed science and industry to progress with greater speed and accuracy.

In addition, as scientific fields such as physics, chemistry, and biology became more interdisciplinary, the standardization of the measurement system also became more critical. A consistent measurement system allowed for easy integration and cooperation across scientific disciplines. Today, the SI system helps underpin global scientific and industrial progress (BIPM, 2019).

Evolution of the SI System

The metric system started in 1795 in France. It aimed to create one standardized measurement system for science, commerce, and everyday life. This need arose because many different measurement systems were being used worldwide, making communication in science difficult and confusing.

The metric system refers to any decimal-based system of measurement. Since the metric system uses units like meters for length, kilograms for mass, and liters for volume, it overlaps with the SI system. Although the terms SI and metric are often used interchangeably, they are different systems.

The major advantage of the metric system is that it uses prefixes to denote powers of ten, making it consistent with the base-ten number system, more universally acceptable, and easier to perform calculations. The metric system was a vast improvement over the idiosyncratic regional units of measure that existed worldwide, but it still had flaws. There were several versions of the metric system. Although all were based on meters, grams, and liters, the various metric systems used different rules.

To illustrate the ease of use of the SI system, at four degrees Celsius, one milliliter of water has a volume of one cubic centimeter and a mass of one gram. Water's density is at its maximum at approximately one gram per cubic centimeter at four degrees Celsius. Raising the water temperature by one degree Celsius requires one calorie of energy (4.18 joules)—the specific heat of water. So, at maximum density, one cubic meter of water has a volume of 1,000 liters and a mass of 1,000 kilograms (one metric ton).

The metric system evolved into the International System of Units (SI) in 1960. The aim was to further standardize and refine the metric system for global scientific and commercial use. The SI system created a uniform and globally accepted measurement system for science and commerce. SI formalized and extended the range of prefixes used in the former metric system.

For example, in the metric system, the meter was defined as one ten-millionth of the distance from the North Pole to the equator along the meridian through Paris, but in the SI system, the meter is based on the speed of light in a vacuum, a universal constant that does not change. The SI Prefixes reference guide lists prefixes from the colossal to the minuscule.

The SI system defines seven base units of measurement: 1) the meter (m) for length, 2) the kilogram (kg) for mass, 3) the second (s) for time, 4) the ampere (A) for electric current, 5) the Kelvin (K) for temperature, the 6) mole (mol) for the amount of substance, and 7) the Candela (cd) for luminous intensity. See the Key Science Units reference guide for a more detailed explanation of the core base and derived units.

The SI units have precise definitions based on physical constants, such as the speed of light in a vacuum or Planck’s constant, providing a very high level of accuracy. The SI expanded the standardized units to include the ampere for electric current, the candela for luminous intensity, and the kelvin for thermodynamic temperature, which were not part of the earlier metric systems (BIPM, 2019; Quinn, 2012).

Conclusion

The SI prefixes allow us to discuss and compute astronomical and subatomic scales more readily. As we delve into the outer reaches of the universe and the subatomic levels of the quantum world, understanding and working with such numbers is more accessible with universally defined and agreed-upon prefixes. The ability to measure on such scales is now indispensable in modern science, especially in fields such as cosmology, nanotechnology, materials science, and quantum computing.

Furthermore, we have only scratched the surface of our understanding of the universe, whether at the cosmological or quantum scales. We have only scratched the surface of how we will use this knowledge to develop different technologies. Science and technology will continue to have sweeping impacts on society.?

Whether through the development of nuclear fusion, the editing of genetic material, the creation of synthetic biological specimens and organisms, or the computation of vast data sets in quantum computing and artificial general intelligence, working with these colossal and infinitesimal scales will continue to become more commonplace. SI prefixes allow us to quantify the universe more accurately, from measuring its vastness to the strange subatomic world of quantum particles.

References

BIPM (Bureau International des Poids et Mesures). (2019). The International System of Units (SI), 9th Edition.

Quinn, T. J. (2012). From Artefacts to Atoms: The BIPM and the Search for Ultimate Measurement Standards. Oxford University Press.

Patrick Blessinger is a lecturer of education at SUNY (Old Westbury), a STEM teacher with NYSED, and chief research scientist for the International Higher Education Teaching and Learning Association or HETL.

Copyright ? [2024] Patrick Blessinger

Disclaimer

Opinions expressed in this article are those of the author and do not necessarily represent the position(s) of other professionals or any institution.

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