Barye

Barye (Ba) is a unit of pressure in the centimeter-gram-second system of units (CGS system), named after the French physicist and mathematician Antoine Césaire Mathias Barye who made significant contributions to the study of pressure and elasticity. It is defined as one dyne per square centimeter (dyn/cm²). The barye is not part of the International System of Units (SI), which uses the pascal (Pa) as the unit of pressure; 1 barye is equal to 0.1 pascal.

Definition and Conversion

The barye is defined based on the CGS system, where pressure is expressed in terms of the force (in dynes) applied per unit area (in square centimeters). Specifically, 1 Ba = 1 dyn/cm². In terms of SI units, since 1 dyne equals 10^(-5) newtons and 1 square centimeter equals 10^(-4) square meters, 1 barye can be converted to SI units as follows: 1 Ba = 0.1 Pa.

Usage

The use of the barye is now largely historical or limited to specific fields, as the SI system, with the pascal as the unit of pressure, has become the standard worldwide. However, the barye may still be encountered in older scientific literature or in the context of specific scientific disciplines that have retained the CGS system for certain calculations.

Relation to Other Units

In addition to the direct conversion to pascals, the barye can be related to other units of pressure through various conversion factors. For example, the atmosphere (atm), another unit of pressure commonly used in meteorology and engineering, is equivalent to 1,013,250 dyn/cm² or 1,013.25 baryes. Similarly, the torr, a unit often used in vacuum measurements, is approximately 1,333.22 baryes.

Historical Context

The barye unit was introduced as part of the CGS system, which was developed in the 19th century as scientists sought to standardize measurements across disciplines. Antoine Césaire Mathias Barye, after whom the unit is named, was a prominent figure in this effort, contributing to the understanding of pressure and its measurement. Despite the shift to the SI system, the barye remains a testament to the historical development of scientific units and the legacy of early researchers in the field of physics.