New SI definitions refer to the recent changes and updates made to the International System of Units (SI), which is the globally recognized metric system for measuring physical quantities. The SI was established in 1960 and has since undergone several revisions to ensure the most accurate and consistent measurement standards across scientific, technological, and trade sectors.
In November 2018, the General Conference on Weights and Measures (CGPM) introduced a significant revision to the SI, centered around the redefinition of several key base units. This was motivated by the need for more precise and standardized measurements, particularly in the fields of quantum physics and metrology.
The revised SI definitions are based on fundamental constants of nature that are considered to be universal and unchanging. For example, the kilogram was previously defined by a physical prototype, but it is now linked to the Planck constant, which provides a more stable and reproducible definition. Similarly, the ampere, kelvin, and mole also received new definitions based on elementary charge, Boltzmann constant, and Avogadro constant, respectively.
The goal of these new SI definitions is to ensure the long-term stability, coherence, and universality of the metric system. By incorporating the latest scientific understanding and technological advancements, these revisions aim to provide more accurate and reliable measurements, benefiting various scientific disciplines, industries, and everyday life.
