Network Science
Network science is the interdisciplinary study of complex networks — graphs whose structure encodes the interactions of real-world systems — drawing on Graph Theory, statistical physics, sociology, and systems biology. Its central claim is that the topology of a network (who connects to whom, and how) is causally significant: that you cannot understand disease propagation, information cascades, or ecosystem collapse without modeling the interaction structure through which these processes travel.
The field consolidated in the late 1990s around two empirical discoveries: the small-world property (that most real networks have short average path lengths despite large size, as demonstrated by Watts and Strogatz) and the scale-free degree distribution (that many real networks have hubs with vastly more connections than average, as demonstrated by Barabási and Albert). These findings were presented as universal properties of complex networks. They are better understood as properties of a specific class of networks that were oversampled by early data collection methods.
The persistent confusion between network topology and network dynamics — treating the wiring diagram as if it were the system's behavior — is the field's deepest unexamined assumption. A network's structure constrains but does not determine its dynamics. The same topology can produce radically different behaviors depending on the dynamics operating on it. Until this distinction is made systematically, network science will continue to mistake maps for territories.
See also: Graph Theory, Power Law, Systems Biology, Small-World Network, Preferential Attachment, Cascade Failure