Archive for the 'Chemistry' Category
The BZ Spiral Reaction
Seemingly spontaneous creation of order from chaos is a pervasive yet still astounding phenomenon in nature that occurs at all scales, from the quantum to the extremely macro scales of measurement and observation. Yet, since scale must be measured in time as well as size, we can rarely observe this ordering or patterning as it is happening. Humans can most often only observe and measure the resulting patterning, not the process of patterning itself.
Fortunately we can view one example of this phenomenon thanks to work done by Anatol M. Zhabotinsky (2007) Belousov-Zhabotinsky reaction. Scholarpedia, 2(9):1435
The Belousov-Zhabotinsky (BZ) reaction is a family of oscillating chemical reactions. During these reactions, transition-metal ions catalyze oxidation of various, usually organic, reductants by bromic acid in acidic water solution. Most BZ reactions are homogeneous. The BZ reaction makes it possible to observe development of complex patterns in time and space by naked eye on a very convenient human time scale of dozens of seconds and space scale of several millimeters. The BZ reaction can generate up to several thousand oscillatory cycles in a closed system, which permits studying chemical waves and patterns without constant replenishment of reactants.
The Belousov-Zhabotinsky Autocatalytic Reaction in progress is shown below:
Belousov-Zhabotinsky Autocatalytic Reaction
The BZ Spiral Reaction is an example of self-organization, a process whereby patterns spontaneously emerge from disordered systems. It is a type of autocatalytic reaction. The reaction starts at random points in the chemical mixture, but a feedback loop is created that triggers more reactions at those same starting places. The reactions then spread out in all directions so you end up with a circular or elliptical wavefront.
The BZ Spiral Reaction allows us to observe the process by which chaotic systems are brought into order. We can then extrapolate with some small measure of surety the apparently similar processes that we cannot directly observe in action.
Such observations are key to unlocking the methodology of the creation of our universe and the later rise of life within it (abiogenesis).
Resources & Reading
Further information on spontaneous patterning arising in nature can be found in Dr. Philip Ball, PhD’s Nature’s Patterns: A Tapestry in Three Parts:
When speaking of the living world, Ball seeks to go beyond the theory of natural selection, which explains why we see certain characteristics (height, shape, camouflage), to find mechanisms that can explain how such characteristics come to be. Again, this is no easy task, but for those willing to follow his discussion, the elegance of nature is laid out in zebras’ stripes, ivy leaves, and butterfly wings. Moving on to find the same patterns at work in the clouds of Jupiter and the cracks in the San Andreas fault give strength to the feeling that there are self-composing structures that guide everything in the universe toward a kind of order.






