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How Gauss Taught Us the Best Way to Hold a Pizza Slice

wired.com

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Re: How Gauss Taught Us the Best Way to Hold a Pizza Slice

#5
More of an engineering problem that uses a bit of math. Unless you can state what the weight would be to cause the surface to collapse, you're just wanking off in math space.

See Second moment of Inertia (or area depending on who you talk to) https://en.wikipedia.org/wiki/List_of_area_moments_of_inerti...

Re: How Gauss Taught Us the Best Way to Hold a Pizza Slice

#7
The author's point that "curvature imputes stiffness" conflates several different and distinct mechanisms, and offers an inadequate explanation.

For the examples of the pizza, the leaf, and the corrugated sheets, the stiffness is due to the fact that the bending moment of inertia of the cross-section increases when we fold the pizza or the sheet in a particular way [1]. The Theorema Egregium shows that such a structure can be made from a flat sheet of material, not that this construction imparts stiffness to the structure.

The example of arches show the well-known arch action in mechanics, where forces are carried through pure compression without any tensile stresses, which makes it appropriate for using stones to make the arch [2]. In principle, one could make a triangular "arch", i.e. part of a truss structure, where we use two straight rods joined together at the top [3]. This shows that its not really the curvature that is giving the stiffness.

The example of hyperbolic paraboloids shows arch action in one direction and beam bending in the other.

The examples of the egg and the can show that it is hard to break a surface when it does not have stress concentrations [4].

So the point is that there's a lot of classical solid mechanics at play here, of which the author seems to be unaware.

[1] http://en.wikipedia.org/wiki/Bending

[2] http://en.wikipedia.org/wiki/Arch

[3] http://en.wikipedia.org/wiki/Truss

[4] http://en.wikipedia.org/wiki/Stress_concentration

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