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Improved packing of equal circles on a sphere and rigidity of its graph

Published online by Cambridge University Press:  24 October 2008

T. Tarnai
Affiliation:
Hungarian Institute for Building Science, Budapest, Dávid F.u.6., H-1113, Hungary
Zs. Gáspár
Affiliation:
Technical University of Budapest, Department of Civil Engineering Mechanics, Budapest, Müegyetem rkp. 3. H-1111, Hungary

Abstract

How must n equal non-overlapping circles be packed on a sphere so that the angular diameter of the circles will be as great as possible? In the paper, the conjectured solutions of this problem for n = 18, 27, 34, 35, 40 are improved on the basis of an idea of Danzer. Using the theory of bar structures it is ascertained that, in these cases, the edge-length of the graphs of the circle-packings can be increased till, in the graphs, additional edges appear which prevent further motions apart from rigid motions. The cases of n = 17 and 32 are also dealt with and there are references to the possibilities of further applications of the method applied in this paper (n = 59, 80, 110, 122).

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1983

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References

REFERENCES

(1)Asimow, L. and Roth, B.The rigidity of graphs. Trans. Amer. Math. Soc. 245 (1978), 279289.CrossRefGoogle Scholar
(2)Calladine, C. R.Modal stiffnesses of a pretensioned cable net. Int. J. Solids structures 18 (1982), 829846.CrossRefGoogle Scholar
(3)Coxeter, H. S. M.The problem of packing a number of equal nonoverlapping circles on a sphere. Transactions of the New York Academy of Sciences. Ser. II 24 (1962), 320331.CrossRefGoogle Scholar
(4)Danzer, L. Endliche Punktmengen auf der 2-Sphäre mit möglichst grossem Minimalabstand. Habilitationsschrift (Göttingen 1963).Google Scholar
(5)Tóth, L. FejesRegular figures. (Pergamon Press, New York, Oxford, 1964).Google Scholar
(6)Tóth, L. FejesLagerungen in der Ebene auf der Kugel und im Raum. Zweite Auflage. (Springer-Verlag, Berlin, Heidelberg, New York, 1972).CrossRefGoogle Scholar
(7)Gáspár, Zs.Buckling models for higher catastrophes. J. Struct. Mech. 5 (1977), 357368.CrossRefGoogle Scholar
(8)Gluck, H. Almost all simply connected closed surfaces are rigid. Geometric Topology, Lecture Notes in Mathematics, no. 438 (Springer-Verlag, Berlin, 1975), pp. 225239.CrossRefGoogle Scholar
(9)Goldberg, M.Packing of 18 equal circles on a sphere. Elemente der Mathematik 20 (1965), 5961.Google Scholar
(10)Goldberg, M.An improved packing of 33 equal circles on a sphere. Elemente der Mathematik 22 (1967), 110111.Google Scholar
(11)Goldberg, M.Axially symmetric packing of equal circles on a sphere. Ann. Univ. Sci. Budapest. Eötvös, Sect. Math. 10 (1967), 3748.Google Scholar
(12)Jucovič, E.Umiestnenie 17, 25 a 33 bodov na guli. Mat. Fyz. Časopis. Slovensk Akad. Vied. 9 (1959), 173176.Google Scholar
(13)Karabinta, A. Arrangements optimaux d'empilement et de recouvrement de cercles sur la sphère. (Thèse de doctorat de 3-ème cycle). Centre Pédagogique Supérieur, Bamako 1973.Google Scholar
(14)Leech, J.Equilibrium of sets of particles on a sphere. Math. Gaz. 41 (1957), 8190.CrossRefGoogle Scholar
(15)Makai, E. Jr and Tarnai, T.Morphology of spherical grids. Acta Tech. Acad. Sci. Hungar. 83 (1976), 247283.Google Scholar
(16)Melnyk, T. W., Knop, O. and Smith, W.R. Extremal arrangements of points and unit charges on a sphere: equilibrium configurations revisited. Canadian Journal of Chemistry 55 (1977), 17451761.CrossRefGoogle Scholar
(17)Poston, T. and Stewart, I.Catastrophe theory and its applications (Pitman, London, 1978).Google Scholar
(18)Robinson, R. M. Note on some arrangements of points on the sphere. Manuscript unpublished, August 1966.Google Scholar
(19)Rutishauser, H.Über Punktverteilungen auf der Kugelfläche. Comment. Math. Helv. 17 (1945), 327331.CrossRefGoogle Scholar
(20)Samuels, P. and Stevens, J.Instability of dual eigenvalue fourth-order systems. J. Struct. Mech. 10 (1982), 209225.CrossRefGoogle Scholar
(21)schütte, K. und Van Den Waerden, B. L.Auf welcher Kugel haben 5, 6, 7, 8 oder 9 Punkte mit Mindestabstand ein Platz? Math. Ann. 123 (1951), 96124.CrossRefGoogle Scholar
(22)Strohmajer, J.Über die Verteilung von Punkten auf der Kugel. Ann. Univ. Sci. Budapest. Eötvös, Sect. Math. 6 (1963), 4953.Google Scholar
(23)Szabó, J.The equation of state-change of structures. Periodica Polytechnica, Mech. Engng 17 (1973), 5571.Google Scholar
(24)Szabó, J. und Roller, B. Anwendung der Matrizenrechnung auf Stabwerke (Akadémiai Kiado, Budapest, 1978).Google Scholar
(25)Székely, E.Sur le problème de Tammes. Ann. Univ. Sci. Budapest. Eötvös, Sect. Math. 17 (1974), 157175.Google Scholar
(26)Tammes, P. M. L.On the origin of number and arrangement of the places of exit on the surface of pollen-grains. Recueil des travaux botaniques néerlandais 27 (1930), 184.Google Scholar
(27)Thompson, J. M. T. and Gáspár, Zs.A buckling model for the set of umbilic catastrophes. Math. Proc. Cambridge Philos. Soc. 82 (1977), 497507.CrossRefGoogle Scholar
(28)Thompson, J. M. T. and Hunt, G. W.A general theory of elastic stability (Wiley, London, 1973).Google Scholar
(29)Thompson, J. M. T. and Hunt, G. W.Towards a unified bifurcation theory. Zeitschrift für angewandte Mathematik und Physik 26 (1975), 581604.CrossRefGoogle Scholar
(30)Van Der Waerden, B. L.Punkte auf der Kugel. Drei Zusatze. Math. Ann. 125 (1952), 213222.CrossRefGoogle Scholar
(31)Van Der Waerden, B. L.Berichtigung zu der Arbeit B. L. van der Waerden in Zürich: Punkte auf der Kugel. Drei Zusätze. Math. Ann. 152 (1963), 94.CrossRefGoogle Scholar