Elementary model of intracellular (or intra-organellar) pattern formation: Belousov – Zhabotinsky reaction in a Petri dish. The Belousov – Zhabotinsky reaction (Belousov 1958) was devised as a primitive model of citric acid cycle. To the surprise of the authors, it brought about the phenomenon of chemical clock (in mixed systems) or spontaneous pattern formation (in still compartments). We use ...

The finite-wavelength instability gives rise to a new type of wave in reaction-diffusion systems: packet waves, which propagate only within a wave packet, are found in experiments on the Belousov-Zhabotinsky reaction dispersed in water-in-oil AOT microemulsion (BZ-AOT) as well as in model simulations. Inwardly moving packet waves with negative curvature occur in experiments and in a model of th...

Experiments are presented on pattern formation in the Belousov-Zhabotinsky (BZ) reaction in a blinking vortex flow. Mixing in this flow is chaotic, with nearby tracers separating exponentially with time. The patterns that form in this flow with the BZ reaction mimic chaotic mixing structures seen in passive transport. The behavior is analyzed in terms of a mixing time taum and a characteristic ...

In this essay I examine the ways in which the Belousov– Zhabotinsky (BZ) reaction is being used by biologists to model a variety of biological systems and processes. The BZ reaction is characterized as a functional model of biological phenomena. It is able to play this role because, though based on very different substrates, the model and system modeled are examples of the same type of excitabl...

We explore geometry of London’s streets using computational mode of an excitable chemical system, Belousov-Zhabotinsky (BZ) medium. We virtually fill in the streets with a BZ medium and study propagation of excitation waves for a range of excitability parameters, gradual transition from excitable to subexcitable to non-excitable. We demonstrate a pruning strategy adopted by the medium with decr...

The synchronization of two distributed Belousov-Zhabotinsky systems is experimentally and theoretically investigated. Symmetric local coupling of the systems is made possible with the use of a video camera-projector scheme. The spatial disorder of the coupled systems, with random initial configurations of spirals, gradually decreases until a final state is attained, which corresponds to a synch...

Patterns in reaction-diffusion systems generally consist of smooth traveling waves or of stationary, discontinuous Turing structures. Hybrid patterns that blend the properties of waves and Turing structures have not previously been observed. We report observation of dash waves, which consist of wave segments regularly separated by gaps, moving coherently in the Belousov-Zhabotinsky system dispe...

In cellular automata models a glider gun is an oscillating pattern of nonquiescent states that periodically emits traveling localizations (gliders). The glider streams can be combined to construct functionally complete systems of logical gates and thus realize universal computation. The glider gun is the only means of ensuring the negation operation without additional external input and therefo...

Almost 30 years have passed since the discovery of concentric (target) and spiral waves in the spatially extended Belousov-Zhabotinsky (BZ) reaction. Since then, rotating spirals and target waves have been observed in a variety of physical, chemical, and biological reaction-diffusion systems. All of these waves propagate out from the spiral center or pacemaker. We report observations of inwardl...

We have found a variety of oscillating patterns in the Belousov-Zhabotinsky (BZ) reaction-diffusion system with global negative feedback. Bulk oscillations and wave patterns arise at low values of the feedback strength. When the feedback exceeds a critical value, cluster patterns arise. Besides the standing, irregular, and localized clusters observed earlier, we have found new types of clusters...