sovrapposizione

Sovrapposizione is an Italian noun meaning the act or result of placing one thing over another, or of two or more elements occupying the same space, time, or set of properties. It is used in a broad, mostly technical sense to describe both literal overlapping and figurative combinations, where different layers, signals, or effects are superimposed.

In science and mathematics, sovrapposizione is closely associated with the principle of superposition. In linear systems, the total response to multiple stimuli is the sum of the responses to each stimulus taken separately. This idea applies to waves, electric and acoustic fields, and quantum states, where a system can exist in a combination of states and where complex solutions are obtained by adding simpler, individual solutions.

In geology and earth sciences, the term is linked to the law of superposition (principio di sovrapposizione): in undisturbed stratified rocks, the oldest layers lie at the bottom and younger ones successively overlie them. This principle enables relative dating and the reconstruction of geological history, though it can be complicated by processes such as folding, faulting, or intrusion.

Beyond these fields, sovrapposizione appears in contexts such as cartography and geographic information systems, where map layers are overlaid; in signal processing, when multiple signals are superimposed; and in general discourse to describe overlapping phenomena or features.