Isotropo

Isotropo is an adjective used in physics, materials science and related fields to describe a property that is the same in all directions. The term comes from the Greek iso- meaning equal and tropos meaning way or direction. In physics, isotropy refers to invariance of a system under rotations, meaning its physical properties do not depend on orientation. Isotropy is distinct from homogeneity, which concerns uniformity through space; a body can be homogeneous but not isotropic, and vice versa.

In materials science, an isotropic material has identical mechanical and thermal properties in all directions. For such materials, the elastic response is often described by a simplified form of Hooke’s law using two independent constants. Most liquids and glasses are isotropic at macroscopic scales, and many polycrystalline metals and polymers can be treated as isotropic when their microstructure lacks a preferred direction. By contrast, anisotropic materials, such as single crystals and wood, exhibit properties that vary with direction.

In optics, isotropy means that the speed of light and the refractive index are the same in all directions. Anisotropic materials, like calcite, can split light into different polarized components (birefringence).

In cosmology, the cosmological principle posits that, on large scales, the universe is statistically isotropic around any point, which supports the observed uniformity of the cosmic microwave background.

Notes: real systems are often approximately isotropic; small anisotropies can arise from microstructure or external fields.