Bokuchi culture

Construction and buildings

Houses and small buildings are often made of adobe (ghien), which is industrially produced. Canals and streams are scooped up for mud, and several varieties of plants are grown for the necessary fibers (the remains of food crops are sometimes also used). Raw adobe gains further cohesion by using a treatment with an organic glue (oenisilit), produced by bacteria.

The adobe factories produce blocks of several sizes. There are three series of blocks sizes, named 6-series, 12-series, and 18-series, and each has three items, which we will call S-size, M-size, and L-size. The sizes are all based on powers of the 'golden number' or phi, about 1.618, expressed in ziyikh (a measurement unit that equals about 9.8 mm, or 6/16 of an inch). The 6-series S-size block measures 9.7 x 15.7 x 25.4 ziyikh, since 9.7 is the product of 6 times phi, 15.7 is 9.7 times phi, and 25.4 is 15.7 times phi. The M-size block measures 15.7 x 25.4 x 41.1 ziyikh, and the L-size block measures 25.4 x 41.1 x 66.5 ziyikh. Therefore, the sizes within the 6-series are the product of 6 times increasing powers of phi. In the same fashion you get the 12-series and 18-series block sizes (the 18-series L-size block is the largest, almost two metres long).

Houses are seldom higher than two floors above ground, but the Bokuchi are quite adept to underground floors, which are used for food storage and as bedrooms, as well as the habitual uses of a basement in our culture.


The golden number

The golden number or golden proportion is one of those numbers with many special properties, like e (the base of natural logarithms) or pi (the ratio between the diameter and the length of a circumference). It's considered the aesthetically most pleasant proportion between the sides of a rectangle; it appears in the proportions of the regular pentagon, in the disposition of leaves in plants, and many other places. It's the number x whose reciprocal (1/x) is such that their difference is 1; thus it can be calculated easily with a quadratic equation:

    x - 1/x = 1   (original equation)
x - 1 - 1/x = 0   (basic algebra!)
x^2 - x - 1 = 0   (square every term to get the canonical form)
          x = (1 + sqrt(1 - 4*1*(-1))) / (2*1)
          x = (1 + sqrt(5)) / 2

(In truth this equation has two solutions, 1.618... and -0.618... We choose the positive one because it fulfills the original equation.)

The powers of phi from 2 up are as follows:

phi^2 =  2.61803398874989484820458683436564
phi^3 =  4.23606797749978969640917366873128
phi^4 =  6.85410196624968454461376050309691
phi^5 =  11.0901699437494742410229341718282
phi^6 =  17.9442719099991587856366946749251
phi^7 =  29.0344418537486330266596288467533

The well-known mathematic Fibonacci discovered that the series of numbers that carries his name, which starts with 0 and 1 and follows with integers such as each one is the sum of the two previous ones (0, 1, 1, 2, 3, 5, 8, 13, 21, 34...), has the following interesting property: if you divide each number by the previous one, the quotient oscillates around the value of phi, and approaches it more and more as the series tends to infinity.