expanding

Expanding is the act or process of becoming larger, longer, or more extensive. It can refer to physical growth, the increase of size or volume, or the broadening of scope, such as ideas, processes, markets, or datasets.

In physics and engineering, thermal expansion describes how materials change size with temperature. Linear, area, and volumetric expansion are described by coefficients, such as the linear expansion coefficient α and the volumetric coefficient β. Practical effects include the need for expansion joints in bridges and rails, tolerances in engine blocks, and precautions in spacecraft to manage temperature-induced stresses.

In cosmology, the expansion of the universe refers to the increasing separation between distant galaxies due to space-time expansion, described by general relativity and quantified by the Hubble constant. Local forces, such as gravity and electromagnetism, counteract this expansion, so most bound systems do not participate in cosmic expansion.

In economics and management, expansion denotes growth in a company, market reach, or product lines, typically pursued via investment, diversification, or mergers. In mathematics and computer science, expansion can describe properties of graphs (expander graphs) or transformations that increase coverage or size, and it can refer to enlarging data sets or feature spaces in analysis.