Speaker 1: Welcome to tech Stuff, a production of I Heart Radios
Speaker 1: How Stuff Works. Hey there, and welcome to tech Stuff.
Speaker 1: I'm your host, Jonathan Strickland. I'm an executive producer with
Speaker 1: I Heart Radio and I love all things tech, and guys,
Speaker 1: things have gotten a little hectic over at I Heart
Speaker 1: Radio headquarters. We're running around all over the place working
Speaker 1: on special projects. And the way it impacts us right now, guys,
Speaker 1: is that I just haven't had the time to be
Speaker 1: able to research and write full new episodes. So we're
Speaker 1: gonna be doing a couple of reruns just for the
Speaker 1: time being. Don't worry. New episodes are right around the corner.
Speaker 1: I just I need to be in the same city
Speaker 1: for two days in a row and then I think
Speaker 1: I can probably you know, bang a couple out. But
Speaker 1: in the meantime, I thought maybe we would enjoy this episode,
Speaker 1: which originally aired back in two thousand sixteen. It's called
Speaker 1: How Tech Could Make Better Chocolate, and it's all about
Speaker 1: a a Temple University project in which scientists were using
Speaker 1: electric fields to improve chocolate. And you know, being the
Speaker 1: holiday season with lots of chocolate all around, I figured
Speaker 1: what better time to revisit this than Now, so enjoy
Speaker 1: this classic episode. How Stuff Works Now if you aren't familiar,
Speaker 1: is our more news oriented page, So if you go
Speaker 1: to now dot how stuff works dot com you can
Speaker 1: see it. We have a lot more stories that are
Speaker 1: reflective of things that are unfolding now, thus the name,
Speaker 1: and we also do video for that. There's also a
Speaker 1: podcast hosted by Lauren Vogelbaum. You can subscribe to that
Speaker 1: How Stuff Works Now. It's a summary of some of
Speaker 1: the stories that we cover each week. So if you're
Speaker 1: not familiar with that, go check it out. It's pretty awesome. Anyway,
Speaker 1: I did this story about chocolate and making sure you
Speaker 1: could reduce the viscosity of liquid chocolate so that it
Speaker 1: does and gum up stuff because one of the challenges
Speaker 1: of working with chocolate is making sure that it doesn't
Speaker 1: clog up the pipes like Augustus Gloop in Willy Wonka.
Speaker 1: So a consulting firm working on behalf of Mars Incorporated,
Speaker 1: which is a giant candy company that makes a lot
Speaker 1: of different chocolate products. This consulting firm went to a
Speaker 1: group of physicists at Temple University, and physicist is one
Speaker 1: of those words. I have difficulty pronouncing. I think I
Speaker 1: might just say scientists. Scientists at Temple University. Hey, that's
Speaker 1: way better. And these guys have developed a method to
Speaker 1: make crude oil flow more easily through pipes using electric fields.
Speaker 1: So the question that the consulting firm had was could
Speaker 1: you do the same thing you did for crude oil
Speaker 1: for chocolate? And here's a spoiler alert, Yeah they could.
Speaker 1: But I want to talk more about what they did
Speaker 1: and how they did it because it's it's a really
Speaker 1: interesting story. So I'm gonna go into a bit more
Speaker 1: detail about the physics and the technology behind the scientist
Speaker 1: solution for this problem. It's pretty cool and a lot
Speaker 1: of it was stuff I had no idea about before
Speaker 1: I began to research the story. So today's episode is
Speaker 1: going to be about chocolate. It's gonna be about viscous fluids,
Speaker 1: about electro real logical fluids, and how an electric field
Speaker 1: can change their fluid I properties, specifically viscosity. So yeah,
Speaker 1: this episode is gonna be science heavy. But here's also chocolate,
Speaker 1: so stick around. You know, everyone loves chocolate. So let's
Speaker 1: get into the physics first. Now, fluid dynamics is pretty
Speaker 1: complicated and also there's some stuff that's related to this
Speaker 1: that falls into the category of misinformation about viscosity. So
Speaker 1: I'll be talking a lot about not just the principles
Speaker 1: in general, but some specific uh myths that I would
Speaker 1: like to bust, as some of my former workers used
Speaker 1: to do on a regular basis. So, first of all,
Speaker 1: viscosity is a property of fluids or semi fluids, and
Speaker 1: it can be described as a fluids thickness or stickiness
Speaker 1: and its resistance to flowing due to internal friction. More accurately,
Speaker 1: viscosity is a measure of the resistance of a fluids
Speaker 1: deformation due to tensile or shear stress. Now, shear stress
Speaker 1: is mechanical stress that's parallel to the surface of that substance.
Speaker 1: So you could think of sheer stress as it's not perpendicular.
Speaker 1: It's not like an impact, right, it's more of a
Speaker 1: tearing ten style. Stress is a pulling stress rather than
Speaker 1: a compression stress. So again, instead of compressing stuff closer together,
Speaker 1: it's about pulling stuff further apart. And water has a
Speaker 1: pretty low viscosity, Honey has a very high viscosity. So
Speaker 1: we actually measure viscosity and units called poises p o
Speaker 1: I s e s. Water at room temperature twenty degrease
Speaker 1: celsius or so has a viscosity of zero point zero
Speaker 1: one poises or a center poise. In other words, a
Speaker 1: thick oil might have a viscosity of one point zero poise. Now,
Speaker 1: we measure viscosity with a viscometer. I'm not making that up.
Speaker 1: That's actually the name of the tool used to measure
Speaker 1: a fluids viscosity. Now, typically we will call a liquid
Speaker 1: viscous if its viscosity is higher than that of waters,
Speaker 1: and if the viscosity is lower than that of waters,
Speaker 1: because water is not the least viscous material that we
Speaker 1: know of, if it has a lower viscosity than water,
Speaker 1: we call that fluid mobile. So some fluids are so
Speaker 1: viscous that they can actually seem to be a solid.
Speaker 1: And this leads us to that misinformation I was talking about.
Speaker 1: It's one of those things that I hear bandied about
Speaker 1: prey the well, not not not as frequently as it
Speaker 1: used to, but it's one of those miss understandings that
Speaker 1: gets passed around its fact every now and again, and
Speaker 1: that is the idea that glass is one of these
Speaker 1: fluids that glass is actually a fluid that is um
Speaker 1: so viscous that it appears to be a solid, and
Speaker 1: that is not true. Glass is not a very very
Speaker 1: viscous fluid. It's a little more complicated than that. Uh So,
Speaker 1: here's the basic idea. People have noticed that if they
Speaker 1: look at windows and very old buildings like medieval churches,
Speaker 1: they see that the base of the window is thicker
Speaker 1: than the top of the window. And this has led
Speaker 1: some people to conclude, to jump to a conclusion that
Speaker 1: the reason why the base is thicker than the top
Speaker 1: is that glass, over the course of centuries has been
Speaker 1: flowing downward and that it's so low that it's not
Speaker 1: detectable under normal situations. It's only over the course of
Speaker 1: centuries that you can see the difference. Uh. Here's the
Speaker 1: problem is that that's just not that's not the case.
Speaker 1: That's not true. It's not what's happening. Uh. If you
Speaker 1: look at the glass making approach in the Middle Ages,
Speaker 1: you'll see why there's a thicker part of the pane
Speaker 1: of glass. Glass was created generally speaking, in the Middle
Speaker 1: Ages through something called the crown glass process. It's a
Speaker 1: pretty neat idea pretty neat way of making glass windows.
Speaker 1: Here's how it worked in general. First, you get your
Speaker 1: raw materials to make glass, and in the Middle Ages
Speaker 1: that was essentially sand and potash, and you mix it
Speaker 1: together and you melt them in a very hot furnace.
Speaker 1: Then you would get a glass blower with a pipe
Speaker 1: and they would get roll out a lump of molten glass,
Speaker 1: put on the ype blow out the glass. So they
Speaker 1: expand the glass outward before flattening it, so they don't
Speaker 1: just you know, create a globe of glass, they actually
Speaker 1: flatten it back out. Then, with the flat glass, which
Speaker 1: is still hot and still malleable, it hasn't cool to
Speaker 1: the point where it is really solidified, you would put
Speaker 1: that on a disk, a spinning disk, and the disk
Speaker 1: spins around to draw out the glass to flatten it further.
Speaker 1: Sort of like how a pizza maker will toss and
Speaker 1: spend dough in the air in order to make that
Speaker 1: circular pizza. It's kind of similar to that. So the
Speaker 1: disc spins and the centripetal force, if you like this,
Speaker 1: pushing the glass outward toward the edges. So then once
Speaker 1: that's done, you would cut the glass into panes so
Speaker 1: that you could fit them in a window. Now, that
Speaker 1: would mean that when you would get anywhere close to
Speaker 1: where the edge of the glass was, the outer edge,
Speaker 1: because you put the glass on that disk and you
Speaker 1: spun it around, the outer edge was thicker than the
Speaker 1: rest of the glass, just because that's where the excess
Speaker 1: was accumulating as it was being uh pushed outward due
Speaker 1: to the spinning motion. So typically window makers would cut
Speaker 1: pains so that a thicker edge would only be on
Speaker 1: one side, and they put that side at the bottom
Speaker 1: at the base of the window, so glass didn't flow
Speaker 1: to the base over hundreds of years. It started out
Speaker 1: like like that. It was like that from the beginning.
Speaker 1: That being said, glass is a really interesting substance. It's
Speaker 1: what we would call an amorphous solid, so saying that
Speaker 1: it's a fluid or a liquid is not accurate. But
Speaker 1: it is an amorphous solid, which is a little hinky
Speaker 1: compared to other materials that you might be familiar with.
Speaker 1: So typically not everything, obviously metals and glass being exceptions,
Speaker 1: but a lot of solids have an ordered crystalline structure,
Speaker 1: so that means the molecules are organized in a pretty
Speaker 1: regular lattice. They form a nice repeating pattern that goes
Speaker 1: throughout the entire material. When you heat up this solid,
Speaker 1: those molecules start to shimmy and shake. Some of the
Speaker 1: molecular bonds might start to break down a little bit,
Speaker 1: the bonds between one molecule and another. The essentially the
Speaker 1: crystalline order breaks down. And if you heat a solid
Speaker 1: beyond its melting point, the crystalline structure completely breaks down
Speaker 1: and molecules will begin to flow freely, or as freely
Speaker 1: as the viscosity of that fluid allows, and there's a
Speaker 1: very clear delineation between the solid and liquid stages. You
Speaker 1: can see the difference molecularly from the way this substance
Speaker 1: looks when it's in solid form versus in liquid form,
Speaker 1: and we call that delineation that border between the two
Speaker 1: the first order phase transition. It's obvious when you look
Speaker 1: at it from a microscopic standpoint. I mean it's obvious
Speaker 1: from a macroscopic standpoint too, because a solid behaves one way,
Speaker 1: in a liquid behaves another way. Now, when you cool
Speaker 1: a liquid down, its viscosity tends to increase. If you
Speaker 1: introduce a nucleation site into the liquid, crystals can form
Speaker 1: and you get that nice solid structure again, once you
Speaker 1: get down below what the melting point was. Uh, but
Speaker 1: glass doesn't do this. Glass doesn't form a crystalline structure.
Speaker 1: Glasses viscosity increases, so it does what other fluids do
Speaker 1: at that point. But since it doesn't crystallize, it solidifies
Speaker 1: in a different way. The molecules actually form an irregular arrangement,
Speaker 1: not that nice ordered structure that you see another solids,
Speaker 1: but that a regular arrangement is still cohesive enough to
Speaker 1: maintain rigidity. So glass does become a solid, It's just
Speaker 1: not a crysp let solid. It's an amorphous solid. Jonathan
Speaker 1: from two thousand nineteen breaking in to say, we'll be
Speaker 1: right back after this quick break. Now, there's no first
Speaker 1: order phase transition here. It's not like if you looked
Speaker 1: at the liquid form of glass and the solid form
Speaker 1: of glass, you would see a massive difference in the
Speaker 1: molecular structure. But there is a second order transition. Now.
Speaker 1: That transition is a little more subtle than first order
Speaker 1: transitions and involves the thermal expansion and heat capacity of
Speaker 1: a material, so it wouldn't be as obvious to casual
Speaker 1: observation on a microscopic level, but there would still be
Speaker 1: differences with the thermodynamics of the material, so we still
Speaker 1: would say the glass is a solid, not a liquid.
Speaker 1: All right, I'm done with glass now, I promise. I
Speaker 1: had to go on that little track just because it
Speaker 1: was related to the stuff I was talking about, and
Speaker 1: I get really irritated seeing that one myth passed around
Speaker 1: as fact. So now you know, if you ever go
Speaker 1: through a a tour and the tour guide says and
Speaker 1: the reason that the windows are thicker at the bottom
Speaker 1: is because glass flows over the course of hundreds of years,
Speaker 1: you can raise your hand and say, well, actually, and
Speaker 1: tell them Josh Clark sent you, because I don't want
Speaker 1: that kind of burden on me. I like being able
Speaker 1: to take tours. Anyway, Let's get back to viscosty in general. So,
Speaker 1: like I said earlier, viscosty is due to internal friction
Speaker 1: of a liquid. And you might think that that sounds weird,
Speaker 1: like how can a liquid have friction inside of it?
Speaker 1: But we're talking about liquids specifically that have like molecules,
Speaker 1: and those molecules can have a tendency to resist getting
Speaker 1: by each other. So some molecules are more resistant to
Speaker 1: slipping by each other than others, or a liquid could
Speaker 1: actually have particles that are suspended in it. It could
Speaker 1: be a suspension, which is different than just a pure liquid.
Speaker 1: But if it's a suspension, it's got particles suspended within
Speaker 1: the liquid at some level of density, right Like some
Speaker 1: maybe a pretty weak suspension where you don't have a
Speaker 1: whole lot, but others could have a greater density of
Speaker 1: particles inside a suspension of fluid. Make chocolate bars, let's say,
Speaker 1: and you're laying out melted chocolate into the mold for
Speaker 1: the chocolate bars, uh, and it clogs up and you
Speaker 1: have to stop production and clean out the clog and
Speaker 1: get everything back up to temperature and start it all
Speaker 1: over again. It's time consuming and expensive when that happens.
Speaker 1: So one solution to preventing it from happening is dilute
Speaker 1: the cacao more so that those particles don't clump up
Speaker 1: as much because there there's a less dense coco component
Speaker 1: in the fluid. That essentially means replacing cacao with something else,
Speaker 1: typically something that is less viscous, like that oil that
Speaker 1: fat essentially, so you usually add more fat to the
Speaker 1: recipe so you get the more fat but less cacao. However,
Speaker 1: it ends up flowing better and creates the chocolate bars
Speaker 1: that you want without creating the clogs. But it's not
Speaker 1: necessarily the best product you could create. It's just the
Speaker 1: most convenient based upon the method of production. So that's
Speaker 1: where this alternative solution comes in. If you could change
Speaker 1: the shape of those cacao particles in the fluid so
Speaker 1: that they packed together more effectively, you would reduce that viscosity,
Speaker 1: that internal friction of the fluid. So imagine you've got
Speaker 1: one of those inflated rubber balls, like like a kickball
Speaker 1: or something. Now, imagine that you're able to grab hold
Speaker 1: on either side of this ball and pull it outward
Speaker 1: so that you're elongating it. Now it would become a
Speaker 1: more of an oval shape, or as the researchers at
Speaker 1: Temple University called them, prolate spheroids. Now, the interesting thing
Speaker 1: about these prolate spheroids is if you align them in
Speaker 1: the direction of the flow of chocolate, you can pack
Speaker 1: more of them together. They have these elongated sides, and
Speaker 1: they will fit together much more snuggly. You can create
Speaker 1: chains of them and chocolate would flow much more readily.
Speaker 1: But how do you change the shape of those COCU particles.
Speaker 1: What is it that you could do to make them
Speaker 1: actually assume a different shape than their natural globular ball
Speaker 1: like shape. This is where electric fields come in. Uh,
Speaker 1: we're gonna talk about applying magnetic or electric fields to
Speaker 1: a fluid to changes viscosity. But first, this doesn't work
Speaker 1: with every fluid. Uh. Not every fluid reacts to electric
Speaker 1: fields and magnetic fields in a way that will alter
Speaker 1: its viscosity. But it does work in fluids that have
Speaker 1: certain non conducting or weakly conducting particles suspended in an
Speaker 1: electrically insulating fluid. Now we call this a special type
Speaker 1: of liquid, electro reological fluid. Electrohological fluids essentially means that
Speaker 1: when you apply an electric or magnetic field to such
Speaker 1: a fluid, it changes its viscosity. Sometimes we also call
Speaker 1: them smart fluids, But more about that in a bit now. Interestingly,
Speaker 1: the property was completely discovered by chance. There was an
Speaker 1: inventor named Willis Winslow who observed the effect in the
Speaker 1: nineteen forties, and he actually patented it in nineteen seven. Now,
Speaker 1: for this reason, we sometimes call this effect of changing
Speaker 1: an electroheological fluids viscosity the Winslow effect, and I'll mostly
Speaker 1: be using that term from here here on out, because
Speaker 1: there's only so many times I'm gonna be able to
Speaker 1: say electroheological before my mouth just decides to rebel against
Speaker 1: the rest of me and march out the door. And
Speaker 1: as entertaining as that would be kind of needed. Hey,
Speaker 1: it's modern day, Jonathan again. We're going to take another
Speaker 1: quick break to thank our sponsor and we'll be right back,
Speaker 1: all right. So, applying an electric or magnetic field to
Speaker 1: such a fluid changes that fluids viscosity within meliseconds like
Speaker 1: it's practically instantaneous, and if you remove the field, the
Speaker 1: particles in the fluid will snap back to their original shape,
Speaker 1: to the fluid's viscosity will return to what it normally
Speaker 1: would be. So the change isn't permanent. It only persists
Speaker 1: as long as the respective field persists, which is super
Speaker 1: cool because you can do these temporary changes that are
Speaker 1: really useful in specific situations and then have it go
Speaker 1: back to normal and it's like it never happened in
Speaker 1: the first place. But one thing to keep in mind
Speaker 1: is the direction of the electric or magnetic field is
Speaker 1: critically important when you want to make a particular effect. So,
Speaker 1: in the case of chocolate, if you apply the electric
Speaker 1: field perpendicular to the direction of flow, you will actually
Speaker 1: increase the viscosity of the chocolate. You will make it
Speaker 1: thicker more like a gel. Melted chocolate will turn into
Speaker 1: this kind of thick gel. It'll otherwise have all the
Speaker 1: same properties that had before, but the viscosity will increase dramatically. However,
Speaker 1: if you were to apply that electric field in the
Speaker 1: direction of the flow of chocolate, then you would decrease
Speaker 1: the viscosity of chocolate and it will flow more freely
Speaker 1: at that point. Now this makes some sense because imagine
Speaker 1: that you have these elongated ovals, these uh prolate sphere poids. Right.
Speaker 1: If you stand them vertically, then you could imagine them
Speaker 1: slipping through a pipe very easily. If you laid them
Speaker 1: out horizontally, you could imagine them ending up like like
Speaker 1: blocking a pipe easily, because it's like trying to fit
Speaker 1: a long stick through a narrow doorway. If you don't
Speaker 1: turn it the right way, you're just gonna hit against
Speaker 1: the door. This is making me think of my dog, Tibolt,
Speaker 1: who has done this on numerous occasions. He just he
Speaker 1: can't get it through his little doggy mind that he
Speaker 1: needs to turn the stick vertical in order to move
Speaker 1: it through a doorway. He just wants to charge ahead
Speaker 1: full steam with the stick horizontal. In many other ways.
Speaker 1: He's an intelligent dog, so we forgive him this lapse
Speaker 1: of judgment. Anyway, the chocolate on a molecular level is
Speaker 1: essentially the same thing. If you are applying this electric
Speaker 1: field perpendicular to the flow of chocolate, then you get
Speaker 1: this much thicker uh mixture. And then interesting side note,
Speaker 1: the electro real logical properties of chocolate aren't a new discovery, right.
Speaker 1: I mean, I covered this story for how stuff works
Speaker 1: now because there was a new application of this property
Speaker 1: with chocolate. But we actually knew that chocolate would react
Speaker 1: this way already, at least to the point of increasing
Speaker 1: the viscosity, because back in there was a Michigan State
Speaker 1: University grad student who observed the Winslow effect on chocolate.
Speaker 1: And his name is Dr Christopher R. Daubert, and as
Speaker 1: professor Dr James Steph worked with him. They both conducted
Speaker 1: experiments on liquid chocolate and observed the Winslow effect. Now,
Speaker 1: in that experiment, Daubert was again increasing the viscostity, not
Speaker 1: decreasing it. So he was turning chocolate into that thicker gel.
Speaker 1: That the liquid chocolate into thick gel. Uh. It wasn't
Speaker 1: until recently that we saw someone try and do the opposite.
Speaker 1: So that brings us to the Temple University experiment. So
Speaker 1: you have these researchers. They had worked on crude oil
Speaker 1: and decrease the viscosity of crude oil, which is a
Speaker 1: huge thing for the oil industry to be able to
Speaker 1: uh move oil more effectively without the fear of clogs
Speaker 1: or viscosity screwing up things that had been planned ahead
Speaker 1: of time. They wanted to see if they could in
Speaker 1: fact use a similar approach to have liquid chocolate move
Speaker 1: more smoothly through a system so that manufacturers could save
Speaker 1: money by not having to worry about cleaning up clogs
Speaker 1: and shutting down production for maintenance. So they had to
Speaker 1: test this hypothesis that an electric field directed in the
Speaker 1: flow of liquid chocolate would reduce viscosity. So they built
Speaker 1: a cool chocolate zapping gadget. It's not really a zapper,
Speaker 1: that's kind of a it's kind of not entirely accurate,
Speaker 1: but I like the idea of using electricity does zap
Speaker 1: chocolate and make it better. That's just a oversimplification of
Speaker 1: what happened, But that's okay. I'll I'll explain to you
Speaker 1: what was actually going on. They built this thing where
Speaker 1: it starts with a bit of a melting chamber. You
Speaker 1: can just think of it as like a a pot.
Speaker 1: It could even be a glass vial. Really, it could
Speaker 1: just be any little container that can hold chocolate. They
Speaker 1: put the chocolate in the container and they cover the container,
Speaker 1: sealing it shut. Uh. They added compressed nitrogen gas into
Speaker 1: the chamber simply really to to just increase the pressure
Speaker 1: inside the chamber itself. The chamber was heated so that
Speaker 1: you had chocolate melting into a liquid. There was a
Speaker 1: thermocouple in there to make sure that the temperature was
Speaker 1: correct so that the chocolate would not overheat or cool
Speaker 1: down so much that it becomes solid again. And then
Speaker 1: the base of this container was essentially a drain, so
Speaker 1: there's like a hole at the bottom of the container
Speaker 1: that liquid chocolate could float. Attached to that was a tube,
Speaker 1: and inside the tube they put a series of metal
Speaker 1: mesh screens and the screens were what generated the electric field.
Speaker 1: They had electricity running to those screens and creating electric
Speaker 1: field that way in the direction of the flow of chocolate,
Speaker 1: so the chocolate would end up flowing very smoothly through
Speaker 1: the tube and didn't have any issues. At the other end,
Speaker 1: they had another vessel container that the liquid chocolate would
Speaker 1: flow into, it would cool down solidify. So once that
Speaker 1: liquid chocolate flowed through into the collecting vessel UH and
Speaker 1: once it was free of the electric field, the cacao
Speaker 1: particles they went back to their original shape immediately. Again,
Speaker 1: they didn't have to transform or anything. It wasn't a
Speaker 1: gradual process. They moved back into those globe shapes that
Speaker 1: they typically are in, and the chocolate cooled and solidified
Speaker 1: and was to all intents and purposes, indistinguishable from the
Speaker 1: chocolate that was being fed through at the top, you know,
Speaker 1: at that top chamber. So they were able to reduce
Speaker 1: the viscosity of the flowing chocolate UH and to the
Speaker 1: to the point where it was no there were no
Speaker 1: issues of clogging. It was perfectly fine. So they were
Speaker 1: able to prove that their hypothesis was correct, that in fact,
Speaker 1: this electric field applied in this way would decrease chocolates viscosity, hooray.
Speaker 1: But there's more to it than that, So this experiment
Speaker 1: was not just a success. The researchers actually realized that
Speaker 1: it had a lot more implications than just having chocolate
Speaker 1: flow freely through a machine. Uh that Again, the reason
Speaker 1: why chocolate has such a relatively high fat content is
Speaker 1: to create that oily fluid to reduce viscosity, to have
Speaker 1: the cacao particles suspended within it at a density that's
Speaker 1: low enough so that you're not likely to clog up
Speaker 1: the machines. But if you use this approach, if you
Speaker 1: use the electric fields to reduce the viscosity, you don't
Speaker 1: need as much oil or fat in your chocolate content.
Speaker 1: You could actually start with a recipe that has less
Speaker 1: fat in it, and the electric fields would take care
Speaker 1: of the viscosity problem, so you don't have to have
Speaker 1: as much fat there. That also means you can have
Speaker 1: more cacao in your mixture. It could be a higher
Speaker 1: proportion of the overall recipe. So they found that they
Speaker 1: could reduce the fat content in certain types of chocolate
Speaker 1: by as much as twenty percent and still have no
Speaker 1: negative impact on the fluid's viscosity. Now it depends on
Speaker 1: what type of chocolate they were using. They were they
Speaker 1: were actually using name brand chocolates, you know, like like
Speaker 1: chocolate bars, you know. They would try different types, and
Speaker 1: depending on the type, they could actually end up removing
Speaker 1: up to the fat in the mixture and still have
Speaker 1: the chocolate flow without any problems. And beyond that, the
Speaker 1: researchers said that people who were tasting the chocolate afterward,
Speaker 1: because keep in mind, other than the fact that there
Speaker 1: was less fat in it, there was really no difference
Speaker 1: between the original chocolate and the end result, they said
Speaker 1: that the end result chocolate actually tasted better to them.
Speaker 1: He said, I had a more intense cacao flavor. It
Speaker 1: was more chocolated than the original chocolate. Now that could
Speaker 1: be just subjective, or it could be purely psychological, but
Speaker 1: it's not outside the realm of possibility that by increasing
Speaker 1: the the proportion of chocolate of cocao in your mixture,
Speaker 1: because you've removed some of the fat so you've got
Speaker 1: more cacao per unit of chocolate than you would previously,
Speaker 1: that you would all so effect the taste. It is
Speaker 1: entirely possible that that is true. It hasn't really been
Speaker 1: tested on a scientific level. It's mostly people saying this
Speaker 1: tastes really good. Also, I should mention this is not
Speaker 1: the same as fat free chocolate. Fat free chocolate is
Speaker 1: essentially using some different type of fluid other than oil
Speaker 1: to suspend cocow particles. So fat free chocolate is has
Speaker 1: that particular weird taste. It's not It's not the same
Speaker 1: as the stuff that Typal University was producing. So uh,
Speaker 1: I just want to clear that up. It's not like
Speaker 1: you would take a bite of a brand new chocolate
Speaker 1: bar that was made using this procedure and they, oh,
Speaker 1: this tastes like fat free chocolate. No, So the end
Speaker 1: result here is that we could end up with better
Speaker 1: tasting chocolate with less fat in it in the future,
Speaker 1: which seems pretty awesome to me. Now, earlier I mentioned
Speaker 1: that electro rheological fluids are also called smart fluids. That's
Speaker 1: because these fluids can change their viscosti almost instantly in
Speaker 1: the presence of an electric or magnetic field, and then
Speaker 1: go right back to what they were before once the
Speaker 1: field has turned off, and they become really important in
Speaker 1: ways beyond making superior chocolate. For example, car manufacturers have
Speaker 1: been using smart fluids and suspension and breaking systems. Uh.
Speaker 1: The fluid can actually go from relatively thin too thick
Speaker 1: in just a moment's notice, which makes it superior to
Speaker 1: a lot of mechanical solutions that would take time to
Speaker 1: propagate through a system. And you can have a variable
Speaker 1: suspension in this way. Imagine that you have a suspension,
Speaker 1: it's a fluid suspension, like literally it's a suspension for
Speaker 1: a car with fluid in it, not that it was
Speaker 1: a fluid that has a suspension in it. It's kind
Speaker 1: of confusing. So car suspension's got fluid in it. Very
Speaker 1: high end sports cars have these, and you can set
Speaker 1: your suspension to different modes, like you can predetermine which
Speaker 1: mode you want at any given time. So let's say
Speaker 1: you're gonna be driving on like a racetrack, a nice
Speaker 1: smooth racetrack, and you're really gonna push the car to
Speaker 1: its limits. You might want a pretty stiff suspension for
Speaker 1: that to really be able to feel the car as
Speaker 1: you're driving along this very smooth surface. But that stiff
Speaker 1: suspension would be torture device if you were driving down
Speaker 1: a normal everyday road that had some bumps and maybe
Speaker 1: some potholes in it. That would be very jarring. You
Speaker 1: would feel every single little bump. So in that case,
Speaker 1: you'd want a more you know, loose suspension, a little
Speaker 1: spring in it. So you might want to reduce the
Speaker 1: viscosity of the fluid inside the suspension to allow for
Speaker 1: more uh give really, and you could do that with
Speaker 1: a smart fluid and just change the electric or magnetic
Speaker 1: field that ends up affecting the viscosity of the fluid.
Speaker 1: So you can actually have settings and say I want
Speaker 1: a very stiff suspension and in this circumstance, and so
Speaker 1: it generates the electric field, the viscosty increases and you
Speaker 1: get your stiff suspension, or he might say, oh, I
Speaker 1: want it to be a more forgiving suspension, and it
Speaker 1: turns off that electric field, the viscosity decreases and you
Speaker 1: have your more your your suspension when more given it.
Speaker 1: It's a pretty cool idea. At chat with Scott Benjamin
Speaker 1: about this before I came in here, he was very
Speaker 1: interested when I started talking about chocolate, but then when
Speaker 1: I started talking about smart fluids, he really lit up
Speaker 1: because he knew exactly what I was talking about. I mean,
Speaker 1: Scott is a car genius and knows everything there is
Speaker 1: to know about cars, it seems. So we had a
Speaker 1: good discussion about, you know, the physical properties of smart
Speaker 1: fluids and why they behave the way they do. So
Speaker 1: this technology could be used in lots of different applications
Speaker 1: moving forward. When you can induce a mechanical change in
Speaker 1: a fluid with something as simple as an electric or
Speaker 1: magnetic field, a lot of different opportunities open up. But
Speaker 1: for me, you know, I'm happy with the chocolate thing.
Speaker 1: I'm going to settle for that. I do love me
Speaker 1: some chocolate, al right, guys, Well, this kind of wraps
Speaker 1: up this episode where I really wanted to look at
Speaker 1: the physics and technology behind ostensibly making chocolate manufacturing more
Speaker 1: smooth and efficient, but ultimately could result in better, more delicious,
Speaker 1: less fattening chocolate. That doesn't necessarily mean we should all
Speaker 1: go out and eat more chocolate, by the way, not
Speaker 1: that that ever stops me, but I feel like, as
Speaker 1: an adult, I have to at least say, don't go
Speaker 1: out and just eat more chocolate. Even if we ultimately
Speaker 1: have chocolate with less fat in it. That's not that's
Speaker 1: not a good excuse. Uh, do as I say, not
Speaker 1: as I do. Anyway, I wanted to invite you guys
Speaker 1: to get in touch with me. Let me know what
Speaker 1: sort of topics he would like me to cover in
Speaker 1: the future. I've got some interesting future topics lined up.
Speaker 1: He would like a quick peek into the future. Pretty soon,
Speaker 1: I'm going to be doing an episode about the story
Speaker 1: of Pisar. I'm gonna do a full maybe two parter
Speaker 1: on that, because it's a it's a good long story.
Speaker 1: I've got a an interview lined up with some folks
Speaker 1: to talk about Amazon Alexa and developing apps for that
Speaker 1: and what Alexa might mean in the future. I've got
Speaker 1: UH an episode lined up with Mr Scott Benjamin, whom
Speaker 1: I just mentioned about robo rites, and also the tragic
Speaker 1: tale of the first death and an autonomously operated vehicle. Guys,
Speaker 1: I hope you enjoyed that episode, the classic how Tech
Speaker 1: could Make Better Chocolate? And we'll have a couple more reruns,
Speaker 1: probably in the next few days. But don't worry. As
Speaker 1: I said, we have new episodes planned UH in a
Speaker 1: very short order, including the annual Lovely Year and Review
Speaker 1: episode that typically takes me about four times longer to
Speaker 1: research and right than any other episode because I have
Speaker 1: to look back at all the different big stories from
Speaker 1: the previous twelve months. But I do it because one
Speaker 1: it's important and too I love you guys, so I
Speaker 1: hope you guys enjoyed this. If you have any suggestions
Speaker 1: or questions or anything like that, send me an email
Speaker 1: the addresses tech stuff at how stuff works dot com,
Speaker 1: or drop me a line on Facebook or Twitter. The
Speaker 1: handle for both of those is tech stuff h s W.
Speaker 1: Don't forget to go to our website that's text stuff
Speaker 1: podcast dot com, that has an archive of every single
Speaker 1: episode we've ever published, plus a link to our online
Speaker 1: store where every purchase you make goes to help the
Speaker 1: show and we greatly appreciate it, and I'll talk to
Speaker 1: you again really soon. Text Stuff is a production of
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