Saturday, January 11, 2014

Tessellation

click photo to enlarge
Language is full of connections, which, if you make them, increases your understanding and use of language, but also expands your enjoyment of it too. Many years ago, when I was studying an aspect of mathematics, I was introduced to the word "tessellation" and the essential concepts that underpin it. At a basic level this involves the tiling of a flat surface with a finite number of geometric shapes such that there are no gaps or overlapping. The square tiles of a bathroom wall tessellate; so too do the hexagonal cells of honeycomb. However, as a branch of mathematics tessellation goes far beyond such simple examples. So too does tessellation in art. The Sumerians tessellated their clay tiles, as did the Islamic architects of the Alhambra in Spain; both used many different tessellating shapes. The Dutch graphic artist, M.C. Escher (1898-1972) famously created pictures with tessellating birds, dogs, lizards and all manner of other things.

When my lecturer used the word "tessellation" it immediately occurred to me that I'd already come across "tessellated" in school geography in connection with a feature in sedimentary rock known as a tessellated pavement, whereby erosion produces the effect of a layer of interlocking tiles. The word "tessera" also popped into my mind. This is the name for the individual pieces of a mosaic such as the Romans used for villa floors or the Byzantines used in their wall mosaics of religious and other subjects. It hadn't occurred to me before, but tessera means tile, more specifically, a 4-sided shape, and its meaning had been extended to describe all close-fit tiling of whatever shape.

On our most recent visit to London we came across a relatively new building near the Thames Cable Car. Ravensbourne College is the work of the Foreign Office Architects and, unusually in a modern British building, it has exterior walls that are tessellated with pentagons and triangles. Interestingly that's not necessarily what the first-time viewer notices because its other distinguishing feature is that every window above the ground floor level is circular! The building is certainly eye-catching. It is located next to the enormous and distinctive O2 (formerly known as the Millennium Dome) so one can understand the architects wanting it to claim its space.

photograph and text © Tony Boughen

Photo 1
Camera: Sony RX100
Mode: Aperture Priority
Focal Length: 37.1mm (100mm - 35mm equiv.)
F No: f8
Shutter Speed: 1/200 sec
ISO:125
Exposure Compensation: -0.3 EV
Image Stabilisation: On