Pikkus

Pikkus is the Estonian word for length. In general usage, pikkus denotes the extent of an object or space along a given dimension, and in scientific contexts it corresponds to the physical quantity known as length. In physics, length is a scalar quantity describing how long something is, or the straight-line distance between two points when considered along a single dimension.

Units and prefixes: The SI unit of length is the meter (m). Length is commonly expressed with metric prefixes such as kilometer (km), centimeter (cm), and millimeter (mm). In everyday contexts, these units describe how long objects are or how far one travels, while in geometry and physics the concept applies to measuring distances along a line or path.

Measurement and concepts: Direct measurement methods include rulers, tape measures, calipers, and laser rangefinders. For the length of a curved path, the concept of arc length is used, which requires summing infinitesimal elements or integrating along the path. The circumference of a circle is its length and is given by 2πr.

Standards and usage: Length has been standardized in the International System of Units (SI). The meter has evolved through definitions based on fundamental constants to ensure precise, reproducible measurements. Pikkus is a foundational notion across science, engineering, construction, textiles, and navigation, where consistent measurement of sizes and distances is essential.

Etymology and language note: In Estonian, pikkus derives from pikk, meaning long, and is used to express length in everyday language and technical writing. It is related conceptually to distance, height, and breadth, but distinct in most contexts from those specific dimensions.