it's a it's it's a there's this viral video going around where someone puts spaghetti into a macaroni Noodle and it shoots out little spaghetti projectiles so does this actually work well let's take a little piece of macaroni and a piece of spaghetti and see what happens this is crazy this actually works I want to see why this is happening how does spaghetti magically turn into tiny projectiles that get launched with a lot of force just by inserting them into macaroni breaking spaghetti by itself is one of the most interesting failure phenomenon that I know of
when you break something stiff like a pencil normally it just breaks in two pieces but with spaghetti that's not the case when you bend spaghetti like this on its end it almost never snaps into just two pieces so it almost always snaps in two or more places leaving little pieces flying everywhere if we look in slow motion you can see how it breaks sending these tinier pieces flying everywhere so if this intrigues you you're not alone in this clip from a 1993 Nova episode about the great physicist Richard feineman his friend talks about how one
night he and fan were making spaghetti and he broke one and it broke into three pieces so he said hey Richard why does this happen so they spent the next two hours coming up with crazy theories about why spaghetti breaks in three pieces and doing different experiments with the spaghetti but at the end of it all he said they had a bunch of broken spaghetti and no good theory for why spaghetti breaks into three pieces it wasn't until recently that researchers were able to figure out why spaghetti breaks like this in 2005 two French researchers
were able to mathematically model why this happens by modeling the Dynamics of bent rods that are suddenly released so you think that when you're bending the spaghetti and then one point gets beyond the limit of curvature and it breaks that would release the tension in the rod and you'd end up with just two pieces but what actually happens is when that first break happens somewhere in the rod then this sends a flexal wave down the rod this flexal wave actually increases the curvature of the spaghetti so you can see that the little Kink happens right
in the rod here that's where the next break happens but then in 2018 researchers further discovered that it's actually possible to make spaghetti break into only two pieces if you twist the spaghetti really hard so this combination of twisting and bending waves combined so that the spaghetti no longer goes past the limit of curvature and breaks in only two pieces but it's really hard to do you have to bend it to at least 250° past its starting point which you can't really do with your hand that easily this is why if you ever break spaghetti
before cooking it I don't know why but some people do it you can see that little pieces fly everywhere but if you give it a Twist first it doesn't break into as many pieces they also found that when you bend the spaghetti fast it sends acoustic and bending waves down the rod that pre- weaken the spaghetti so this causes it to fracture into many small pieces and not just three or four like normally see when I move it really fast it breaks into a lot of pieces now all of this is for spaghetti being broken
in open space but what happens when we confine the edges of the spaghetti well let's look at this 3D printed curved tube that will act as our macaroni this works so much better than the macaroni say hello to my little friend I've left one side open so we can see inside it as it's fracturing and shooting first you can see that the spaghetti is only breaking at one spot for each fracture so by confining the spaghetti we can break it into only two pieces not three or more like we get when it's unconfined and at
each break the short end of the spaghetti goes launching out of the tube so where's that linear energy coming from we'll notice at each fracture Point how the ends of the spaghetti move very quickly away from the fracture Point well we can turn that fast moving rod end into linear motion by hitting it against a slanted Edge for example if I drop the spaghetti on a slanted surface the spaghetti will get launched forward after it hits the slanted surface so the slanted edge of the tube right here redirects the momentum of the fast moving spaghetti
edges and it turns it into linear momentum to launch the tiny piece of spaghetti out the end of the tube it's amazing how much force is generated from this small break in the spaghetti okay this is crazy watch how fast this actually shoots now it may seem that spaghetti has some magical properties to be able to break in this amazing way but actually any brittle elastic Rod will do the same thing for example when a pull valter's pull breaks it will generally not just break in two pieces but a lot of times it'll snap into
three or more pieces like showing here it just turns out that spaghetti is just the right strength and length and it's easy enough to to Break by hand and it also happens to fit directly into a macaroni piece which led to the discovery of the macaroni launcher now if you want to try the spaghetti launcher this is large elbow macaroni number 74 it seems to work pretty well but I had to buy it on Amazon to get the big diameter a lot of times macaroni is a lot smaller I'll also put the STL file in
my description for the 3D printed launcher this works way better than the noodles and thanks for watching another episode of the action lab I hope you learned something if you haven't subscribed to my channel yet remember to hit that subscribe button and we'll see you next time
