Aste T., Weaire D. Pursuit of perfect packing (IOP 2000)(147s).pdf
Aste T., Weaire D. Pursuit of perfect packing (IOP 2000)(147s).pdf
Aste T., Weaire D. Pursuit of perfect packing (IOP 2000)(147s).pdf
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
8 Loose change and tight <strong>packing</strong><br />
Figure 2.3. (a) A polygon with a disc inside can be divided into triangular sectors with<br />
angles . (b) The isosceles triangle that touches the disc is the sector that minimizes the<br />
area for a given . The area <strong>of</strong> such a sector is a convex function <strong>of</strong> , therefore a division<br />
in equal sectors is best.<br />
So equal angles are best, and the strategy <strong>of</strong> equal shares results in Ò such<br />
isosceles triangles.<br />
Packing many discs<br />
We are ready to complete the pro<strong>of</strong> <strong>of</strong> the disc-<strong>packing</strong> problem in two dimensions:<br />
what is the most dense arrangement <strong>of</strong> equal discs, infinite in number The<br />
answer will be the triangular close <strong>packing</strong> <strong>of</strong> figure 2.1.<br />
In his book, which covers many such problems 1 , Fejes Tóth attributes the<br />
½ Fejes Tóth L 1953 Lagerungen in der Ebene auf der Kugel und im Raum (Die Grundlehren der<br />
Math. Wiss. 65) (Berlin: Springer).