Emergence in Science

Abstract: In the scientific literature, the term emergent phenomena is invoked in the context of a collective behavior observed in a complex adaptive system that exhibits no correspondence with the behavior of the system constituents. Although this description is too generic to be termed a definition, it alludes to the fact that emergent phenomena are closely related to esoteric observations and neoteric developments in science. With these impressions, we aim to investigate a variety of observed behavior from the perspective of an emergentist. Starting with a few familiar portrayals of emergence, we devote a large body of this narrative review to explain instances of emergence in condensed matter systems, namely the phase transition phenomena, spontaneous symmetry breaking, and macroscopic quantum phenomena. At the same time, to present a broader perspective, we cross the domain boundaries to also provide a succinct description of emergent phenomena prevailing in social sciences, economics, computing environments, and in biological systems, as well.