Revista Brasileira de Ensino de Física
On-line version ISSN 1806-9126
AMAKU, M.; MORALLES, M.; HORODYNSKI-MATSUSHIGUE, L. B. and PASCHOLATI, P. R.. Fractals in the didactic laboratory. Rev. Bras. Ensino Fís. [online]. 2001, vol.23, n.4, pp. 422-428. ISSN 1806-9126. http://dx.doi.org/10.1590/S0102-47442001000400008.
The concept of objects with a fractal structure is discussed, in the context of their use in motivating activities for the didactic Laboratory. Spheres of squashed bread, which may be employed as non-fractal counter example (D ~ 3,0) to the fractal crumpled paper balls (D ~ 2,5), were analysed and the need for correct computation of the uncertainties is stressed. Three kinds of bread were investigated: two white ones, an usual sandwich and an italian type, and one very heavy three grain german dark bread. Only the white italian bread showed a possible fractal structure after the squashing procedure, characterized by the dimension 2.81 ± 0.06, while the results for the others, respectively D = 2.95 ± 0.06 and D = 2.98 ± 0.04, for the dark and white sandwich breads, do not typify them as fractals. The conceptual problems, which resulted in a fractal dimension of D = 2.08 ± 0.25 for bread, found in an article in the literature, are analysed.