# Evil Genius Labs

Custom Electronic Art

Custom Electronic Art

Ducenti (Lux Phyllotaxis) is a beautiful 11” stainless steel hemispherical light art display. Swirling and pulsing like a colorful galaxy, it’s mesmerizing to watch. It exists at the intersection of art, math, science, and geometry.

It consists of 200 RGB LEDs, arranged into a spherical Fermat’s spiral pattern.

In disc phyllotaxis, as in the sunflower and daisy, the mesh of spirals occurs in Fibonacci numbers because divergence (angle of succession in a single spiral arrangement) approaches the golden ratio. The shape of the spirals depends on the growth of the elements generated sequentially. In mature-disc phyllotaxis, when all the elements are the same size, the shape of the spirals is that of Fermat spirals—ideally. That is because Fermat's spiral traverses equal annuli in equal turns. The full model proposed by H Vogel in 1979^{[2]} is

where *θ* is the angle, *r* is the radius or distance from the center, and *n* is the index number of the floret and *c* is a constant scaling factor. The angle 137.508° is the golden angle which is approximated by ratios of Fibonacci numbers.^{[3]}

Fermat's spiral. (2015, October 24). In *Wikipedia, The Free Encyclopedia*. Retrieved 02:45, February 24, 2016, from https://en.wikipedia.org/w/index.php?title=Fermat%27s_spiral&oldid=687297594