Columbia Encyclopedia

Search results

104 results found

states of matter

(Encyclopedia)states of matter, forms of matter differing in several properties because of differences in the motions and forces of the molecules (or atoms, ions, or elementary particles) of which they are composed...

balance

(Encyclopedia)balance, instrument used in laboratories and pharmacies to measure the mass or weight of a body. A balance functions by measuring the force of gravity that the earth exerts on an object, i.e., its wei...

differential geometry

(Encyclopedia)differential geometry, branch of geometry in which the concepts of the calculus are applied to curves, surfaces, and other geometric entities. The approach in classical differential geometry involves ...

calculator

(Encyclopedia)calculator or calculating machine, device for performing numerical computations; it may be mechanical, electromechanical, or electronic. The electronic computer is also a calculator but performs other...

population

(Encyclopedia)population, the inhabitants of a given area, but perhaps most importantly, the human inhabitants of the earth (numbering about 7.5 billion in 2017), who by their increasing numbers and corresponding i...

number

(Encyclopedia)number, entity describing the magnitude or position of a mathematical object or extensions of these concepts. A real or complex number z is called algebraic if it is the root of a polynomial equati...

sex

(Encyclopedia)sex, term used to refer both to the two groups distinguished as males and females, and to the anatomical and physiological characteristics associated with maleness and femaleness. Sex relates to the t...

space station

(Encyclopedia)space station or space platform, artificial earth satellite, usually manned, that is placed in a fixed orbit and can serve as a base for astronomical observations; zero-gravity materials processing; s...

ion, in chemistry

(Encyclopedia)ion, atom or group of atoms having a net electric charge. Ionization has many applications. Vapor lamps and fluorescent lamps take advantage of the light given off when positive ions recombine with ...

pressure

(Encyclopedia)pressure, in mechanics, ratio of the force acting on a surface to the area of the surface; it is thus distinct from the total force acting on a surface. A force can be applied to and sustained by a si...