Comments on: The pasta problem

The pasta problem

Wet Spot — Mon, 15 Aug 2005 20:13:11 -0800

It was one of the great riddles of the cosmos. Along with black holes, the structure of space-time and the origins of the Big Bang, some of the greatest scientific minds have struggled with the dry spaghetti question. Why does uncooked spaghetti snap into more than two pieces when bent?

By: tiamat

tiamat — Mon, 15 Aug 2005 20:18:56 -0800

because I said so?

By: smackfu

smackfu — Mon, 15 Aug 2005 20:30:32 -0800

That's a great web version of what is probably a really technical paper. The reason they come up with is completely unintuitive. I know I wouldn't believe you if you told me spaghetti could break just by bending it and letting go.

By: braun_richard

braun_richard — Mon, 15 Aug 2005 20:40:54 -0800

I don't understand. The article says that pasta breaks in THREES, but that has never been the case with me. It always breaks into SEVERAL pieces. In fact, the pic in the articles shows it breaking into several pieces!

By: drpynchon

drpynchon — Mon, 15 Aug 2005 20:51:43 -0800

Umm no, the article states that pasta breaks into multiple pieces (AT LEAST 3).

By: braun_richard

braun_richard — Mon, 15 Aug 2005 21:01:38 -0800

I guess I just don't know why pasta breaking into multiple parts is such a surprise. I mean, it's a brittle, thin substance, and it will break into multiple parts. Of course, getting pasta to break into two pieces is extremely easy, if you're careful and hold it correctly.

By: smackfu

smackfu — Mon, 15 Aug 2005 21:06:09 -0800

BTW, I was just playing with this and I can't reproduce their experiment at all. If I hold one end and bend the other and let it go (like their catapult effect), it either doesn't break, or it breaks when I'm bending it. It never breaks when I let it go. Maybe I'm missing something.

By: teece

teece — Mon, 15 Aug 2005 21:08:31 -0800

Really cool. I have often wondered if their are great discoveries waiting to be made in mundane things like this. You don't need (necessarily) black holes or electrodynamics or the model of the atom to come up with brand new physics. braun_richard: the way spaghetti breaks is not at all intuitive to me. If I bend a stick, it breaks at one point, not three of four or five. I would expect a single point of failure, at which point tension is released, so no more breaking should happen. It's not being hit with a hammer, it's being bent until it breaks. Their explanation is fascinating, as it appears that a release of tension increases force. Cool.

By: PareidoliaticBoy

PareidoliaticBoy — Mon, 15 Aug 2005 21:57:13 -0800

*Starts melting cheese*

By: PurplePorpoise

PurplePorpoise — Mon, 15 Aug 2005 22:14:43 -0800

I did not rtfa - heterogeneity in extruded flour amalgam.

By: shoepal

shoepal — Mon, 15 Aug 2005 22:14:49 -0800

Flexural waves, baby! Thanks, Wet Spot!

By: Balisong

Balisong — Mon, 15 Aug 2005 22:16:04 -0800

I'm glad that others are also overwhelmed by the everyday physics that plagues everyday activities.

By: Turtles all the way down

Turtles all the way down — Mon, 15 Aug 2005 22:18:19 -0800

I have often wondered if their are great discoveries waiting to be made in mundane things like this. You don't need (necessarily) black holes or electrodynamics or the model of the atom to come up with brand new physics. In Surely You Must Be Joking, Mr. Feynman Richard Feynman describes being at [some job in some prestigious university] and being totally stuck as to what to study. He went to the cafeteria one day and noticed a plate spinning on the table, and observed how the pattern on the plate seemed to rotate at a different rate than the plate as a whole was rotating (it wasn't really rotating; it was precessing) and then he came up with [some great physical theory that I don't remember or understand]. So, you know, that's like, how it happens sometime, right? I guess. I don't know.

By: PareidoliaticBoy

PareidoliaticBoy — Mon, 15 Aug 2005 22:41:43 -0800

*Minces the garlic*.

By: weapons-grade pandemonium

weapons-grade pandemonium — Mon, 15 Aug 2005 23:37:13 -0800

The brittle steel struts in skyscrapers, buildings and bridges can fragment by similar mechanisms, so this research can have practical implications in helping to make structures safer. Libretto to a Spaghetto: Most bridges are brittle if not cooked a little. I like mine al dente, with a '90 Chianti.

By: 517

517 — Tue, 16 Aug 2005 06:26:14 -0800

Speaking of Feynman, what's the answer to the sprinkler-drain question? (spell check is not kind to Mr. Feynman)

By: wilberforce

wilberforce — Tue, 16 Aug 2005 06:36:37 -0800

It doesn't spin.

By: Smedleyman

Smedleyman — Tue, 16 Aug 2005 08:05:04 -0800

"Their explanation is fascinating, as it appears that a release of tension increases force" Having no small experiance with both spaghetti & breaking things my first reaction was that the spaghetti was brittle and after being radically bent the force from snapping back probably stressed it even more. So these guys conclude that the pasta is broken up by flexural waves. Don't I feel like an asshole. But that's why you contract at the point of contact (then release) when you strike something. That muscle tension prevents the reiteration of that wave back into you, it also helps focus force into the target. It's why the Shaolin backfist works, and yet is worthless when covered in maranara sauce.

By: cmfletcher

cmfletcher — Tue, 16 Aug 2005 08:49:17 -0800

It breaks as such because it is his divine will

By: carsonb

carsonb — Tue, 16 Aug 2005 09:05:08 -0800

If I hold one end and bend the other and let it go (like their catapult effect), it either doesn't break, or it breaks when I'm bending it. - smackfu if i understand you correctly, you're merely bending the spaghetti before letting it go, right? like if you were gonna fling something from one end of it? the experiment as i understood it was that they'd break a piece of dry spaghetti. initially, it would break in one place, and the catapult effect (ie flexural waves) originates from the breaking point with as much force as is needed to break the spaghetti again (and in some cases again and again). does that make any sense? i can't tell as i'm used to pondering dinner later in the day.

By: weapons-grade pandemonium

weapons-grade pandemonium — Tue, 16 Aug 2005 09:38:32 -0800

...the initial break sends waves rippling down the length of the pasta. This wave boosts the curvature of the already bent pasta, triggering a cascade of other breakages, which, in turn, trigger more waves, causing the strand to fragment. It seems sensible that smaller strands break with less curvature, but they would also require more force to break. If you hold one end of the spaghetto with your left hand and bend the other back with your right finger until it breaks, the latter end flies off and breaks again in mid-air. It appears the damping of the left hand causes the energy of the whole to be transmitted to the flying piece. So there's not more energy out than in; it's just redistributed.

By: weapons-grade pandemonium

weapons-grade pandemonium — Tue, 16 Aug 2005 09:41:00 -0800

..as with a slingshot.

By: OmieWise

OmieWise — Tue, 16 Aug 2005 10:03:07 -0800

This is really cool. I had never thought to think about it before, but now I feel like I missed out on thinking about the riddle before it was solved.

By: Citizen Premier

Citizen Premier — Tue, 16 Aug 2005 10:11:15 -0800

So dry spaghetti experiences whiplash?