What is an isotropic material?

An isotropic material is defined as one that has the same physical properties in all directions. This uniformity in characteristics, such as density, elastic modulus, thermal conductivity, and others, is crucial in various applications, especially in engineering and materials science.

For instance, when stress is applied to an isotropic material, the response is the same regardless of the direction of the applied force, leading to predictable and consistent performance. This is particularly important in structural applications where uniform material behavior under load is required to ensure safety and performance.

In contrast, materials that have varying properties, like those described in the first choice, can lead to unpredictable behavior under stress or thermal changes. Similarly, materials that conduct electricity or are opaque may have specific properties but do not necessarily exhibit isotropy.