arcsecond [arcsec] to radian [rad] Converter

Definition: An arcsecond (symbol: '') is a unit of angular measure equal to 1/60 of an arcminute or 1/3600 of a degree. It is used to express very small angles, particularly in astronomy and surveying.

History/origin: Like the arcminute, the arcsecond originates from the Babylonian sexagesimal system.

Current use: Arcseconds are used in astronomy for high-precision measurements of stellar positions, parallaxes, and proper motions. They are also used in surveying and geodesy for precise angle determination.

Definition: A radian is the standard unit of angular measure, used in many areas of mathematics. One radian is defined as the angle subtended at the center of a circle by an arc equal in length to the radius of the circle.

History/origin: The concept of radian measure was developed in the mid-18th century. Roger Cotes was one of the first to recognize the naturalness of using the radius as the unit of angle measurement. The term 'radian' first appeared in print on 1873, in examination questions set by James Thomson at Queen's College, Belfast.

Current use: Radians are widely used in mathematics, physics, and engineering, particularly in calculus, trigonometry, and signal processing. They simplify many formulas and are the standard unit for angular measurement in scientific and mathematical contexts.