  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.
