|Face value||CHF 1.00|
|Face value||CHF 4.00|
|Face value||CHF 2.60|
|Motif||Quotients of adjacent Fibonacci numbers|
The starting point for this series is the touring exhibition Geopythafibotonpolyhypotesaeder! Matheliebe at the Liechtenstein National Museum. In his collection assembled over the years partly of objects made by himself and partly of objects discovered in the course of everyday life the Liechtenstein mathematician Georg Schierscher seeks firstly to awaken a joy and interest in mathematics and secondly to demonstrate how deeply mathematics is rooted in the natural sciences. Here football for example is revealed as a truncated icosahedron and a car headlight as a parabolic reflector. And in the bloom of a sunflower spirals can be detected the number of which is determined by the numerical sequence of the Italian master mathematician Leonardo da Pisa, also called Fibonacci (ca. 1180 to ca. 1241): 0, 1, 1, 2, 3, 5, 8, 13, … Why this is so has to do with the Golden Angle, which in turn is obtained from the Golden Ratio. The Golden Angle is moreover also responsible for the positions of the leaf-nodes, whereby undesirable overlapping of a leaf by overlying leaves is prevented and the optimum light-yield obtained. Precisely what the “Fibonacci sequence” (face value CHF 1.00), the “Quotient of adjacent Fibonacci numbers” (face value CHF 2.60) and the “Golden Ratio” (face value 4.00) are all about is made clear in this highly recommended exhibition.
The three stamps have been designed by the Vaduz graphic artist Hans Peter Gassner. The source he used for his exploration of another mathematical phenomenon in nature is the book “Formvollendet” (“Perfect in form”) by authors Martin Hess and Andreas Uebele. According to this, leaves can be “reconstructed” in a polar coordinate circle with a spiral raster, i.e. there is a kind of standard structural plan to which leaves conform. To illustrate this, Gassner has used as models three leaves of indigenous plants which lend themselves especially well to being “reconstructed”: a vine leaf in autumn, the leaf of an apple tree and the leaf of a Japanese maple.