holes

[miriam_e]

Drill holes in steel and it can be made not only lighter, but paradoxically, stronger too. I was thinking about how the maximum number of holes could perforate a sheet of metal without exposing it to the risk of folding, the way perforated lines in paper like to fold. And then it hit me: daisies and their Fermat spirals. Not a straight line to be seen anywhere.
(See the Wikipedia entry on Fermat's spiral for more info.)

Just realised, I didn't mention how holes can make metal stronger. From what I understand, it is related to how surface tension on water works. All the water molecules pull on each other. In the middle of water they are attracted to each other by a certain amount, but near the surface they pull on each other almost twice as much because there are less neighbors. That is what surface tension is, and why you can float a metal pin on the surface of a glass of water. As I understand it, the same thing is true of the atoms in metals. They pull more tightly against each other at the surface, where there are less neighbors to distribute their pull among.
(Note: It may also have something to do with stresses in forming the holes and deformation of microscopic crystalline structure in the metal, so if my explanation is incorrect please let me know.)