Deep math of the folded pizza slice

Why are you being so hostile about this?

Iā€™m not sure why people think that writers donā€™t make typos. In my experience, writers are responsible for the vast majority of them. Proofreading is not writing.

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If you like this sort of thing, I can highly recommend http://www.amazon.com/The-Classical-Cookbook-Andrew-Dalby/dp/0892363940

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The bolded excerpt is about the Gaussian curvature of an idealized surface, not about the properties of a slice of pizza.

Letā€™s not be idiots about this.

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I guess. Itā€™s just that when a typo results in another word (rather than simply an obviously misspelled word), it seems, I donā€™t know, dumber. Since Boing Boing is really trying hard to look like a professional website, I somehow hold you guys to a higher standard than the average website comment.

Also, donā€™t you guys call yourselves ā€œeditorsā€?

(I sound more hostile than I really feel. Mistakes can happen, of course. But if they happen in public, I feel it my duty to heroically exact public shaming, for the eventual betterment of all.)

@mtdna Having RTFAā€™d, Iā€™d say my comments apply to an even greater degree. The article hangs a lantern on the fact that Gaussā€™s work requires an inelastic surface, then proceeds to make only physical examples, all of which have Youngā€™s moduli, as well as buckling and crippling behaviors, most of which are only empirically understood.

Again, Iā€™m sure that all these principles of structure are related to Gaussian curvature, but claiming that Gauss taught us how to fold pizza is like saying that Newton taught us how to cook it, given that he developed differential calculus (which underpins the principles of heat transfer).

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Awwe I missed all the fun. Came to say the thing about elasticity, but since thatā€™s covered, Iā€™ll say the thing about whereā€™s the ā€œdeep math?ā€ If you want to use Gaussā€™ principle you have to be able to take a partial differential. Woo. Iā€™m sure the proof is harder, but you donā€™t need proof to eat the pizza.

Now, if the pizza had been a Riemann manifold imbedded in another, higher-dimension manifoldā€¦

Clearly Gaussian Curvature is NOT the reason why we fold the pizza slice.
We fold it because thatā€™s a way that works, and Iā€™d suggest we humans learned that from trial and error, whenever we ate things that were thin and floppy, from well before we ever had a concept of mathematical theory.

Gaussian theory may help us explain, in an uneccessarily complex way, why our food flops.
But we can make lightweight, stiff structures quite intuitively, without ever knowing it.

Yā€™aint from around here, are ya?

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In engineering, we call it increasing the ā€œsecond moment of areaā€ otherwise known as the ā€œarea moment of inertiaā€ or simply ā€œthe moment of inertiaā€. It is the same reason some beams flex excessively and others do not.

Doesnā€™t it apply as an approximation to explain why folding the pizza stiffens it in the desired direction? Obviously, you canā€™t stiffen the unbaked dough by folding it because it just stretches.

Deep mathS(!!!) would be for Chicago-style pizza, surely?

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Just for you Corrections, typos, grammar flubs and errors

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No, folding the pizza in either way shown does not change what is called the ā€œintrinsic metricā€. That is, if you draw a bunch of lines on the pizza and then make the fold, neither the angles between the lines nor their lengths change. The amazing thing about Gaussian curvature is that it only depends on the intrinsic metric, not the precise details of how the surface sits in 3-dimensional space.

Now, adding in factors from real life pizza, the derivation of the theorem is going to get some error terms. Youā€™d actually have to go through it all to be sure, but I would think that the error terms would be 3rd order or higher. So unless you have a lot of toppings, the theorem should be close enough to true to make no practical difference.

Iā€™d been reading/watching some tutorials on complex curved shapes in jewelry making and metalworking recently that seem somewhat related.

https://www.google.com/search?q=anticlastic+curvature+gaussian+jewelry&tbm=isch

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Noted. Also, sorry. :-/

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Actually, that assumption does hold for Little Caesars ā„¢.

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People have weird definitions of ā€˜hamburgerā€™ - with some claiming that the meat patty alone can be called a hamburger. For me the minimum requirements to fit the definition is to have 2 buns and a mince meat patty.

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1 bun normally does me, but I like the idea.

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Yeahā€¦ you know what I meanā€¦ 1 bun halved :stuck_out_tongue:

Then thereā€™s this:

(do not watch if hungry or extremely full)

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