Spaghetti Breakage

So it's you who's broken all the spaghettii
Del
(PS I dunno)

Hi Del,

As the well known BBC documentary on the spaghetti plant inferred, I believe it has to do with the type of soil where the plants are cultivated.

Cheers

Vince

I'm not sure that that is true, but...

You can't compare pasta to metal or wood, it is a brittle material while they are ductile. If you hold the ends and rotate them in opposite directions you apply circular bending, the flexural stress is the same all along the beam. I suspect that the spaghetti breaks at one spot, perhaps the application of the moments is imperfect or there is a weak spot, and the longer remnant whiplashes and breaks near the hand. perhaps if the remnants are of similar length, they both whiplash and break again.

Does cast iron break in the same way?

Pretty much the same, it's a little more ductile than pasta, but you don't see long slender pieces of it. It does shatter if you hit it with a hammer.

Someone said that you should put olive oil in the water. ABSOLUTELY NOT. The sauce will not stick to the pasta as it should.

And if it were bath-shaped instead of rod-like?

I agree, see post 34, kind of confirms what you say, check out where the breakage occurs....

You could do one of two things to make the result the same.

Either cook the spaghetti to reduce the bending stresses, or alter the chemistry/heat treat of the beam to more closely resemble a piece of glass.

It actually shatters more like glass than snapping a twig.

Spaghetti is very dry and when it is bent to the breaking point it will shatter as the shock wave from the sudden stress relief shatters neighboring sections that are at or near their own stress limit.

I don't know why people always break spaghetti when they cook it. The proper way is to cook it without breaking it, anyway.

The other thing is that you are probably using cheap spaghetti. :-)

You don't need a large pot, use a cacerole instead, water must be about to boil, put one end of the spaghetti beam in the center of the cacerole, let the other end go and it will form a circular fan, in a few moments the submerged portions of the spaghetti will soften, allowing you to push the ends around the cacerole edges into the water with your bare hands, repeat two or three times and you're done, stirr ocassionally, while you keep an eye on the Bolognesa sauce cooking in a separate pan, cook for about 11.5 minutes and serve with a light salad sparkled with croutons, covered with your favorite dressing and a bottle of wine.

And what time did you say dinner is on?

Any time ! I'm always hungry.

OK. Make sure there's enough.

You're not the first person to be kept awake by such oddities of nature:

http://www.math.psu.edu/belmonte/spaghetti.html

That's good to hear.

Will the left over, boiled spaghetti water freeze faster than fresh tap water?

Only if it has been microwaved!

Not if you add that dash of salt that manufactures recommend.

Pass 'em FEA, or boil 'em dead. S.M.

Interesting you bring this subject up.

I was watching a documentary just last week on the physicist Richard P. Feynman co-winner of the 1965 Nobel Prize in physics.

Its was on You Tube, BBC Horizon, "No Ordinary Genius - Richard Feynman" 1993

Anyways, one of his students talked about him about the types of discussion they would have, They both loved spaghetti and one of the things they discussed and actually what types of experiments they could do was just this topic..................they spent hours, and came to no conclusions...........but don't let that stop this thread.

Maybe it's a government mandate, like tempered glass that is designed to break into many small, harmless pieces when broken.

it breaks into more pieces so they don't have sufficient mass to put your eye out.

This way, no safety glasses are required when breaking your busgetti.

makes sense....

yes you're correct , it is going to be introduced under a NATO agreement too that all spaghetti must be designed this way for safety reasons , the added bonus being that it cant be used as a weapon of mass destruction.

kind of explains why Saddam Hussein wasnt italian

How many, after reading this thread went to the pantry, took a piece of spaghetti and broke it to see if it broke into 3 pieces? I'm not falling for that one.

I don't know about that, But...

how many went to the pantry got the spaghetti and made it.

Nope. Just FEA'd some solid macaroni for now (lol) S.M.

that would be in shear, what about bending and tensile?

Would happily continue this ground-braking research but unfortunately specimens were consumed (with red sauce). S.M.

'....ground-braking....'

Sounds like the antithesis of 'what makes the world go round'.

That "red sauce" is what we Italians call "gravy"....

Me.

I've often wondered that too; it seems very counter intuitive to me.

A really high speed camera would probably reveal quite a lot. Maybe you should enter next year's radio 4's "So you want to be a scientist competition".

OK now, you did it. You made me get dead serious about it. Here it is. I bet that your camera will reveal that the breakings don't happen synchronously. One breaking happens first, statistically favoring middle, and for some reason spaggheti material breaks again at its other points because of violent elastic energy release at peak or rebound. It can't handle the accelerations it faces approaching the other end of its trajectory, when it changes movement direction, or experiences catastrophic vibrations at its self frequency, initiated by the first shattering, A good spaghetti scientist could investigate the phenomenon even without an expensive fast camera, but with just a mic and a digital scope, I'm sure the braking moments will be visible and delays between them, easily measurable. Studying them will reveal which of the two assumptions happened, the natural frequencies of spaghetti pieces, (half periods of which should be the observed delays if first case is true) and of course the speed of sound on spaghetti. S.M.

See? That's the thing that wants explaining.

the two parts that are spinning are showing that probably half the length of one spinning part created a rotational inertia around its center , creating shear on the secondary break points.

i am not suggesting that is the only force at play , but its likely to be greater than 50 % of the force at play , otherwise the broken parts wouldnt be spinning with residual momentum

if the material was a different thickness then the natural harmonic would manifest with break points at different parts of its length .

i suspect the breakage indicates there is also a node point where the ability of the material to transmit resonant forces at a given speed along its length coincides with the forces of the bending moment within it , both combining to create the "catastrophic failure" where it occurs

~ ~ enuff . this converstaion is not going to change the world

My hypothesis............ok, guess, there is a shock wave after the first break going threw the spaghetti that over comes the stability, and being held keeps it from continuing to propagating, with the breeak finding its natural harmonics.

.... and/or by holding it the shock wave can not dissipate.

And with that said,...... please pass the sauce.

Great link. If you follow the link at the end of the movie:-

http://www.lmm.jussieu.fr/spaghetti/index.html

You eventually get to what looks like a reasonably well confirmed hypothesis. They start simulating the break by simply letting one end of the spaghetti go.

The mode of fracture is actually a design feature that has taken centuries to perfect.

Folk either like their spaghetti intact or broken.

Those who like unbroken spaghetti have no appreciation for the heightened degree of convenience that this multiple fracture mode provides.

When one enjoys their spaghetti broken they really appreciate the labour savings that this fracture mode provides.

Less time spent breaking spaghetti means more time to do other things.

I like broken spaghetti. It is easier to eat with a spoon alone leaving the other hand free for the TV remote. (or to hold a plate, weapon, whatever....)

It's a labour saving miracle with ancient roots.

Looks like some folks here need to learn how to properly "twirl" unbroken or broken spaghetti with a fork and a large spoon "ITALIAN STYLE"! LMAO

I would guess that the spaghetti is fracturing all along the bend where it is being stressed. When the break finally happens in the middle, the spaghetti snaps back into position with such speed that the fractured ends can't keep up without breaking off. That's why they spin when they break.

The theory of the harmonic vibration is probably correct. So, I did the following to prove it. I took two drinking straws and one piece of spaghetti. I inserted half of the spaghetti strand into on straw and the other half into the other straw. Holding the ends of the two straws together and bending the spaghetti while inside the straws produced two only pieces of spaghetti. No third piece was rendered.

That just proves that the straws prevent the the two end sections from getting too pre-stressed. Follow the link

http://www.lmm.jussieu.fr/spaghetti/index.html

For a full analysis.

The link that you mention is what gave me the idea to do the straw experiment.

OK, I've been holding my tongue too long. Here's a thought;

Anybody recall School experiments testing the strength of a glass rod ? Test a rod to failure**, than test another that has been dipped in acid. The latter will have greater strength*. How is that of any use ?....

Imagine or spaghetti is perfectly uniform...It would break cleanly in the middle. Real Spaghetti is not perfect, and somewhere a weak point will break first. The other (longer) bit gets a bad case of whiplash.

That may be wrong, but pending the time I find where I first heard this one it's the best I can offer.

*Bending a <whatever> to fail point depends upon various factors. One is surface features such as hairline cracks. The angle of radius at the end of that crack is critical. Acid etching will either reuce the radius or eliminate the crack.

This post is sponcered by 6 hours sleep in 72 hours and 2 glasses of cheap plonk.

** I fib slightly, it wasn't a bending test, but the essentials apply.

could be the mixture of egg and flour , a quality issue

Stop press: it's not just spaghetti!

How about that....

Sometimes they break in two not three.

Pesky Russian - throwing a spanner in the works of CR4 discussion !

Anybody got an explanation for the difference between the two vaulting incidents ? Was it angle of attack/the way in which the pole was stressed being different, or maybe they had some difference in the construction of their poles. I'm a little cared to look this one up on google .

Broken in 3

and another

one more