Circle packing in a circle is a two-dimensional packing problem with the objective of packing unit circles into the smallest possible larger circle.
If more than one equivalent solution exists, all are shown. [1]
Number of unit circles | Enclosing circle radius | Density | Optimality | Diagram |
---|---|---|---|---|
1 | 1 | 1.0000 | Trivially optimal. | |
2 | 2 | 0.5000 | Trivially optimal. | |
3 | ≈ 2.155... | 0.6466... | Trivially optimal. | |
4 | ≈ 2.414... | 0.6864... | Trivially optimal. | |
5 | ≈ 2.701... | 0.6854... | Proved optimal by Graham (1968) [2] | |
6 | 3 | 0.6666... | Proved optimal by Graham (1968) [2] | |
7 | 3 | 0.7777... | Trivially optimal. | |
8 | ≈ 3.304... | 0.7328... | Proved optimal by Pirl (1969) [3] | |
9 | ≈ 3.613... | 0.6895... | Proved optimal by Pirl (1969) [3] | |
10 | 3.813... | 0.6878... | Proved optimal by Pirl (1969) [3] | |
11 | ≈ 3.923... | 0.7148... | Proved optimal by Melissen (1994) [4] | |
12 | 4.029... | 0.7392... | Proved optimal by Fodor (2000) [5] | |
13 | ≈ 4.236... | 0.7245... | Proved optimal by Fodor (2003) [6] | |
14 | 4.328... | 0.7474... | Conjectured optimal by Goldberg (1971). [7] | |
15 | ≈ 4.521... | 0.7339... | Conjectured optimal by Pirl (1969). [7] | |
16 | 4.615... | 0.7512... | Conjectured optimal by Goldberg (1971). [7] | |
17 | 4.792... | 0.7403... | Conjectured optimal by Reis (1975). [7] | |
18 | ≈ 4.863... | 0.7609... | Conjectured optimal by Pirl (1969), with additional arrangements by Graham, Lubachevsky, Nurmela, and Östergård (1998). [7] | |
19 | ≈ 4.863... | 0.8032... | Proved optimal by Fodor (1999) [8] | |
20 | 5.122... | 0.7623... | Conjectured optimal by Goldberg (1971). [7] |
Only 26 optimal packings are thought to be rigid (with no circles able to "rattle"). Numbers in bold are prime:
Of these, solutions for n = 2, 3, 4, 7, 19, and 37 achieve a packing density greater than any smaller number > 1. (Higher density records all have rattles.) [9]
Packing problems are a class of optimization problems in mathematics that involve attempting to pack objects together into containers. The goal is to either pack a single container as densely as possible or pack all objects using as few containers as possible. Many of these problems can be related to real-life packaging, storage and transportation issues. Each packing problem has a dual covering problem, which asks how many of the same objects are required to completely cover every region of the container, where objects are allowed to overlap.
In geometry, a sphere packing is an arrangement of non-overlapping spheres within a containing space. The spheres considered are usually all of identical size, and the space is usually three-dimensional Euclidean space. However, sphere packing problems can be generalised to consider unequal spheres, spaces of other dimensions or to non-Euclidean spaces such as hyperbolic space.
In geometry, the Malfatti circles are three circles inside a given triangle such that each circle is tangent to the other two and to two sides of the triangle. They are named after Gian Francesco Malfatti, who made early studies of the problem of constructing these circles in the mistaken belief that they would have the largest possible total area of any three disjoint circles within the triangle.
Karl Georg Christian von Staudt was a German mathematician who used synthetic geometry to provide a foundation for arithmetic.
László Fejes Tóth was a Hungarian mathematician who specialized in geometry. He proved that a lattice pattern is the most efficient way to pack centrally symmetric convex sets on the Euclidean plane. He also investigated the sphere packing problem. He was the first to show, in 1953, that proof of the Kepler conjecture can be reduced to a finite case analysis and, later, that the problem might be solved using a computer.
In Euclidean plane geometry, Apollonius's problem is to construct circles that are tangent to three given circles in a plane (Figure 1). Apollonius of Perga posed and solved this famous problem in his work Ἐπαφαί ; this work has been lost, but a 4th-century AD report of his results by Pappus of Alexandria has survived. Three given circles generically have eight different circles that are tangent to them (Figure 2), a pair of solutions for each way to divide the three given circles in two subsets.
In mathematics, real algebraic geometry is the sub-branch of algebraic geometry studying real algebraic sets, i.e. real-number solutions to algebraic equations with real-number coefficients, and mappings between them.
The Steiner–Lehmus theorem, a theorem in elementary geometry, was formulated by C. L. Lehmus and subsequently proved by Jakob Steiner. It states:
In geometry, circle packing is the study of the arrangement of circles on a given surface such that no overlapping occurs and so that no circle can be enlarged without creating an overlap. The associated packing density, η, of an arrangement is the proportion of the surface covered by the circles. Generalisations can be made to higher dimensions – this is called sphere packing, which usually deals only with identical spheres.
György Hajós was a Hungarian mathematician who worked in group theory, graph theory, and geometry.
Circle packing in a square is a packing problem in recreational mathematics, where the aim is to pack n unit circles into the smallest possible square. Equivalently, the problem is to arrange n points in a unit square aiming to get the greatest minimal separation, dn, between points. To convert between these two formulations of the problem, the square side for unit circles will be L = 2 + 2/dn.
Károly Bezdek is a Hungarian-Canadian mathematician. He is a professor as well as a Canada Research Chair of mathematics and the director of the Centre for Computational and Discrete Geometry at the University of Calgary in Calgary, Alberta, Canada. Also he is a professor of mathematics at the University of Pannonia in Veszprém, Hungary. His main research interests are in geometry in particular, in combinatorial, computational, convex, and discrete geometry. He has authored 3 books and more than 130 research papers. He is a founding Editor-in-Chief of the e-journal Contributions to Discrete Mathematics (CDM).
Square packing is a packing problem where the objective is to determine how many congruent squares can be packed into some larger shape, often a square or circle.
Karl August Reinhardt was a German mathematician whose research concerned geometry, including polygons and tessellations. He solved one of the parts of Hilbert's eighteenth problem, and is the namesake of the Reinhardt polygons.
In geometry, a plesiohedron is a special kind of space-filling polyhedron, defined as the Voronoi cell of a symmetric Delone set. Three-dimensional Euclidean space can be completely filled by copies of any one of these shapes, with no overlaps. The resulting honeycomb will have symmetries that take any copy of the plesiohedron to any other copy.
David Anthony Klarner was an American mathematician, author, and educator. He is known for his work in combinatorial enumeration, polyominoes, and box-packing.
In geometry, it is an unsolved conjecture of Hugo Hadwiger that every simplex can be dissected into orthoschemes, using a number of orthoschemes bounded by a function of the dimension of the simplex. If true, then more generally every convex polytope could be dissected into orthoschemes.
Carl Friedrich Geiser was a Swiss mathematician, specializing in algebraic geometry. He is known for the Geiser involution and Geiser's minimal surface.
Wilhelm Ferdinand Fuhrmann was a German mathematician. The Fuhrmann circle and the Fuhrmann triangle are named after him.