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From:
http://asia.iop.org/cws/article/news/42581
A blog entitled "Fruity Physics" written by Adarsh Sandhu, editor of IOP Asia-Pacific.
Adarsh Sandhu writes:
"Chaorong Li and Zexian Cao are scientists at the Institute of Physics of the Chinese Academy of Science (CAS) in Beijing. In 2004 they began a research project primarily focused on the growth of silicon nanostructures by the co-evaporation of SiOx and Ag2O, where Ag acts as a catalyst, but halfway through they turned their attention to the exploration of stressed patterns and their phyllotactic implications. 'It was pure serendipity that our experiments resulted in the formation of some amazing stress-related patterns on the Ag-core/SiO2 shell microshells,' says Cao. "We explained these results in terms of a shrinking of the microshells during cooling which induce a large stress at the interface, with the result that buckling patterns delineated the most stressed or least stressed points'
"The CAS team found that when the core/shells had a good wetting interface with the substrate, it resulted in a conical surface, and the stressed patterns were Fibonacci parastichous spirals – 3 by 5 to 13 by 21 patterns were obtained in the two senses of chirality. The researchers then realized that Fibonacci spirals were in some sense the same as the triangular tessellation on spherical surfaces, with the differences lying in the topology of the supporting surface. " (the figure shown here)
" 'In 2008, by using numerical simulation of buckling modes on spheroidals of differing skin thickness, we wanted to demonstrate that the myriad of patterns observed on the surfaces of fruits to be of mechanical origin,' says Cao. 'Furthermore, we wanted to produce stressed patterns of high regularity, to show that by puncturing a spherical surface the resulting stressed pattern in triangular lattices, such as the beehives, would be defect free. This may be useful for analysis of self-assembly of nanostructures on curved surface.' "
For marvelous pictures of other Fibonacci spirals in nature, see:
http://www.pinterest.com/pin/176977460328576217/
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