Spirals in nature, in lab, and in simulations

• Seashell spiral patterns
• Spiral waves in the Belousov-Zhabotinsky reaction
• Spiral waves and target patterns in the catalytic CO-oxidation on Pt(110)
• Spirals in the Faraday experiment
• Spirals in Reyleigh-Benard convection
• Living organism: A spiral wave developing in a rabbit heart
• Spirals in colonies of microorganism:cAMP spiral wave formation in Dyctiostelium discodeum
• Spiral waves in Ca2+ dynamics in the Xenopus laevis oocyte
• Whirling turbine: inwardly moving spirals
• Inwardly rotating spiral waves (antispirals) in BZ-AOT
• Spiral gallexy
• Antispirals in 3-component Brusselator and Oregonator models
• Antispirals in a complex Ginzburg-Landau equation and more ...

1. Seashell spiral patterns

Logarithmic spiral(above)
Archimedes spiral , curvature:

Fibonacci numbers 1, 1, 2, 3, 5, 8, 13, 21, and 34 ...

2. Spiral waves in the Belousov-Zhabotinsky reaction

3. Spiral waves and target patterns in the catalytic CO-oxidation on Pt(110)

(J CHEM PHYS 98 (12): 9977(1993))

4. Spirals in colonies of microorganism:cAMP spiral wave formation in Dyctiostelium discodeum

The most familiar strategy of cooperative behavior among such microorganism is attractive chemotaxis. Colonies of the slime mold Dictyostelium discoideum bacteria, when deprived of heat or moisture, start up their cross-talk, this communication allows them to aggregate into multicellular bodies that are more fit survive hardship. Certain cells, called pioneer cells, release pulse of the compound cyclic adenosine monophosphate (cAMP), and nearby cells then follow this chemical trail to its source. Once a cell has emitted a burst of the chemoattractant, it falls silence for several minute, as if recuperating from the exertion. This refractory period means that, when a slime mold colony starts to undergo chemotaxis, it behaves as an excitable medium, then there is no surprise that the slime mold shows target and spiral patterns as BZ retraction.

cAMP spiral waves and target patterns