põhifüüsikalisi

Põhifüüsikalisi is an Estonian adjective phrase used in physics and education to refer to fundamental physical concepts or quantities. In common usage, it appears most often in phrases such as põhifüüsikalised suurused, which translates to fundamental or base physical quantities. The term is not a field of study by itself but a descriptor that helps distinguish core quantities from derived or applied measures.

In the context of physics and the International System of Units (SI), põhifüüsikalised suurused are the base quantities that form the foundation for measuring the physical world. The seven SI base quantities are length (meter), mass (kilogram), time (second), electric current (ampere), thermodynamic temperature (kelvin), luminous intensity (candela), and amount of substance (mole). These base quantities underpin the system of units and serve as the reference points from which other, derived quantities (such as velocity, acceleration, force, energy) are defined.

The distinction between põhifüüsikalisi/ base quantities and derived quantities is common in textbooks and curricula. Base quantities are often taught as the fundamental categories of measurement, while derived quantities are combinations of these bases (for example, velocity as length per time, or force as mass times acceleration). The concept emphasizes a hierarchical view of physical measurement: a small set of fundamental measures supports a broad array of subsequent calculations and descriptions of physical phenomena.

In Estonian usage, the form põhifüüsikalisi is typically encountered in educational materials, glossaries, and scientific writing when referring to these core quantities. The term underscores the idea of foundational physical properties that are essential for quantitative analysis in science. See also SI base units, derived units, and base quantity.