Scientific explorations of spirals and convergence phenomena in mathematics, physics, biology, astronomy, computer science and complex systems.
9 articles · Complex Systems
Two systems can converge toward the same form because they share a constraint, without sharing a history or mechanism. An analytical grid separates analogy, homology and functional convergence.
Two substances that react and diffuse at different speeds can destabilize a uniform state. Depending on parameters and geometry, spots, bands, fronts or spirals appear.
The Lorenz attractor has two lobes around which a trajectory winds irregularly. It is not two stable spirals, but a deterministic dynamic sensitive to initial conditions.
Emergence refers to the appearance of global properties that cannot be deduced from the properties of individual components. Starling murmurations, ant colonies and financial markets are examples.
Kondratiev identified economic cycles of about 50 years in historical data. These waves of expansion and contraction correspond to major technological revolutions, but their existence remains debated.
The SIR model describes epidemic spread through three coupled differential equations. In phase space, the trajectory traces a curve converging toward an equilibrium point.
A food web is a graph of predator-prey relationships. The disappearance of a keystone species can trigger a trophic cascade that propagates through the entire network.
Positive feedback amplifies perturbations; negative feedback dampens them. The dynamics of complex systems are governed by the interaction of these two types of loops.
Stigmergy is an indirect coordination mechanism where agents modify their environment. Ants build nests with complex structures without central coordination, each individual following simple local rules.