Heterogeneous vs. inhomogeneous [closed]

I am puzzled about the word "inhomogeneous." Isn't "heterogeneous", strictly speaking, more correct? Do correct me if I'm wrong, but to me, "inhomogeneous" looks like the Latin prefix "in-" added to a Greek word. As such, it sounds a bit like "aquaphobia" to me.

The two words you name do indeed seem very similar in meaning, but they can serve different purposes in practice. The usefulness of inhomogeneous becomes evident in discussions of variation from a norm or ideal of homogeneity, where the departure from homogeneity may constitute inhomogeneity, while the state of complete nonhomogeneity may be termed heterogeneity.

For example, A.F. Buddington, "On Some Natural and Synthetic Melilites," in American Journal of Science (January 1922), in a discussion of the crystalline states of certain chemical mixtures, refers to different mixtures as "homogeneous," "inhomogeneous," or "heterogeneous." Buddington is clearly aware of the word heterogeneous, since he uses it; but he finds the term inhomogeneous valuable as a way to describe crystalline formations that (in a series of experiments where conditions are varied slightly but systematically) conspicuously cease to be homogeneous.

The vast majority of matches in a Google Books search for inhomogeneous occur in highly technical scientific articles where, presumably, shades of distinction with regard to homogeneity and heterogeneity are especially important.

It's true that many authors use inhomogeneous without also using heterogeneous, but perhaps in those cases using a negative of homogeneous keeps the concept of homogeneity—and its absence—more centrally in view than would be the case if heterogeneous were used in place of inhomogeneous. I certainly wouldn't assume that a writer was using inhomogeneous due to a simple lack of familiarity with the word heterogeneous.

In many cases, of course, authors don't want to put homogeneity (or variance from homogeneity) in the spotlight, in which case heterogeneous may be a better word choice than inhomogeneous.