Speaker 1: Welcome to Tech Stuff, a production from iHeartRadio. Hate there
Speaker 1: and Welcome to tech Stuff. I'm your host, Jonathan Strickland.
Speaker 1: I'm an executive producer with iHeartRadio. And how the tech
Speaker 1: are you. I'm back after my vacation and then the holiday,
Speaker 1: and we're ready to tackle some new episodes. And there
Speaker 1: have been a few really big events in the news
Speaker 1: over the last few weeks that have a tech angle
Speaker 1: to them. There's the ongoing war in Ukraine, which was
Speaker 1: punctuated by a brief but notable coup attempt in Russia.
Speaker 1: There's the ongoing chaos over at Reddit, which has had
Speaker 1: effects far beyond Reddit itself because companies like Google have
Speaker 1: struggled to deliver satisfying search results, while hundreds of popular
Speaker 1: subreddits either remain dark or cluttered with memes, or some
Speaker 1: of them are set to not safe for work status
Speaker 1: and so they're not showing up properly. And then there's
Speaker 1: the Titan submersible, the vehicle where five people perished when
Speaker 1: the submersible suffered a catastrophic failure. I thought today I
Speaker 1: would talk about something relating to that last story. Now
Speaker 1: I'm not going to do a full story about the
Speaker 1: systems aboard the Titan submersible, because a lot of other
Speaker 1: people have already done that to varying degrees. I've seen
Speaker 1: some treatments that were very high level. I've seen one
Speaker 1: really decent video that talked about the various systems. If
Speaker 1: you do want a deeper conversation about the Titan submersible,
Speaker 1: I will go into it. But I figure that because
Speaker 1: there's already all this coverage out there, and even by
Speaker 1: the time this episode goes out, you know, with news
Speaker 1: going as fast as it does, a lot of people
Speaker 1: would already say it's old news. So chances are you
Speaker 1: might already know everything there is to know already. But
Speaker 1: if you would like me to do an episode about
Speaker 1: the Titan submersible and its various systems and how it worked,
Speaker 1: let me know and I will be sure to tackle that.
Speaker 1: So instead, for this episode, I thought I would focus
Speaker 1: on one of the primary materials, not the only one,
Speaker 1: but one of the big ones used in the construction
Speaker 1: of the Titan submersible, which is carbon fiber. I figure
Speaker 1: we can learn about the history of this material and
Speaker 1: what makes it special, and a little bit about how
Speaker 1: it's produced and what applications benefit from it versus ones
Speaker 1: that perhaps are not ideal applications of carbon fiber, because,
Speaker 1: as it turns out, carbon fiber has a lot of
Speaker 1: really good legit uses and applications, but not all of
Speaker 1: them make sense necessarily. But let's start by talking about
Speaker 1: carbon itself, because, as the name implies, carbon fiber is
Speaker 1: made up of carbon. It is the sixth most plentiful
Speaker 1: element in the universe by the number of atoms out there,
Speaker 1: according to Encyclopedia Britannica. That is, it trails behind hydrogen, helium, oxygen, neon,
Speaker 1: and nitrogen. On Earth, carbon doesn't really rank that high
Speaker 1: as far as elements found in the Earth's crust. In fact,
Speaker 1: it makes up about point zero two five percent of
Speaker 1: the Earth's crust. Now, despite this tiny little pathetic showing
Speaker 1: on the Earth's crust, carbon is actually part of more
Speaker 1: compounds than any other element. It can make more compounds
Speaker 1: than any element you can think of. In fact, it
Speaker 1: forms more compounds than all the other elements put together.
Speaker 1: Not put together in a compound, but I mean, like
Speaker 1: all their various combinations that we have discovered. Now you've
Speaker 1: likely heard the fray, the carbon based life form. At
Speaker 1: least you have. If you've watched any science fiction, you've
Speaker 1: probably heard the phrase organic compounds. Well, an organic compound
Speaker 1: is one that contains carbon, and any compound that does
Speaker 1: not contain carbon is an inorganic compound. So why do
Speaker 1: scientists associate the words life and organic with carbon. Well,
Speaker 1: it's because of carbon's tendency to form multitudes of compounds
Speaker 1: at a range of temperatures that we find here on Earth. Right,
Speaker 1: not all elements will form specific compounds under Earth temperatures.
Speaker 1: You might have to go to extremes to create certain compounds,
Speaker 1: but carbon readily forms countless compounds here on Earth just
Speaker 1: in regular Earth conditions. Many of those compounds are polymers.
Speaker 1: Polymers are large molecules that are made up of repeated
Speaker 1: units that are chained together, and all living stuff on
Speaker 1: Earth has carbon in it. So the thinking goes that
Speaker 1: carbon is just so well suited for making all these
Speaker 1: different compounds at temperatures that we associate as being livable
Speaker 1: temperatures that, at least here on Earth, it makes sense
Speaker 1: that it's a foundational element for life. Now, whether that
Speaker 1: is true elsewhere in the universe is hard for us
Speaker 1: to say. We have a sample size of one planet
Speaker 1: that we know to have life on it, and we
Speaker 1: live on it. That's it. We don't know of any
Speaker 1: other planets. It's quite possible there are maybe countless planets
Speaker 1: that have life on them. We don't know about them.
Speaker 1: Carbon's utility and tendency to bind in molecular compounds seems
Speaker 1: to give it an edge over others. But science fiction
Speaker 1: is filled with examples of, say, alien civilizations that turn
Speaker 1: out to be life forms that are based on other
Speaker 1: elements like silicon. It's just that carbon. Because it's such
Speaker 1: an interesting element, and it does form all these compounds
Speaker 1: so readily under earthlike conditions, we figure this is probably
Speaker 1: a cornerstone for life, at least life as we understand it.
Speaker 1: Carbon is non metallic. You know, if you burn wood
Speaker 1: down into charcoal, that's carbon. That's the charcoal is carbon.
Speaker 1: If you squeeze it hard and hot and long enough,
Speaker 1: which sounds a bit racy, but if you do that,
Speaker 1: then obviously you get a diamond. Carbon's really neat. Depending
Speaker 1: upon its molecular arrangement, it can be soft enough to
Speaker 1: use as pencil lead that would be graphite, right, Like,
Speaker 1: that's soft enough where if you drag the lead across vapor.
Speaker 1: It leaves some of it behind, right, it's just the
Speaker 1: pressure of your hand pushing the pencil against paper is
Speaker 1: enough to rub some of the carbon off. That's graphite,
Speaker 1: But it could also be made into a diamond, which
Speaker 1: is hard enough to cut most other materials. Again, it's
Speaker 1: all in that molecular structure. How are those carbon atoms arranged,
Speaker 1: and that's what really matters. How do those carbon atoms
Speaker 1: form crystaline structures. That determines the features of the material
Speaker 1: that you end up with in aggregate, whether that's coal
Speaker 1: or charcoal or diamond or anything like that. So that's
Speaker 1: carbon in a nutshell. Well, obviously you could spend multiple
Speaker 1: university level chemistry classes talking about it. I mean, the
Speaker 1: whole branch of organic chemistry focuses on it. But for
Speaker 1: our purposes we're gonna leave off from there because really
Speaker 1: there's not much more to say about it when we're
Speaker 1: talking about carbon fiber. So let's turn our attention there.
Speaker 1: And by the way, first of all, if you're in America,
Speaker 1: you're probably spelling fiber fiber, and if you're a brit
Speaker 1: you're probably spelling it fiber bray I bre Now I've
Speaker 1: already mentioned that carbon can form polymers, these long chain
Speaker 1: molecules that have repeating structures in them. A carbon fiber
Speaker 1: is essentially a really really long one of these, or
Speaker 1: rather a tube made up of these carbon nanotubes, by
Speaker 1: the way, kind of takes the same concept, but down
Speaker 1: to the nano level. Anyway, carbon fiber material ends up
Speaker 1: being lightweight and strong. It can be electrically conductive. It
Speaker 1: can also be thermally conductive, depending upon the carbon fiber
Speaker 1: used in the process you use to produce it. We'll
Speaker 1: talk more about the qualities of carbon fiber in a bit,
Speaker 1: but before we get to that, let's talk about its
Speaker 1: actual history. The story of carbon fiber is fascinating and
Speaker 1: it involves the inventor of the incandescent light bulb. And
Speaker 1: some of y'all clever smarty pants out there already know
Speaker 1: I'm being coy because I am not talking about Thomas Edison.
Speaker 1: Thomas Edison did not invent the incandescent light bulb. Now
Speaker 1: here in America. One of Edison's many nicknames is the
Speaker 1: Inventor of the light bulb. But the truth is that
Speaker 1: Joseph Wilson swan over in the UK, beat Edison to
Speaker 1: the punch by a couple of decades, and he did
Speaker 1: it using carbon fiber as a filament, or at least
Speaker 1: eventually he did use carbon fiber. So we're talking around
Speaker 1: eighteen sixty here, and before figuring out how to make
Speaker 1: carbon fiber, Swan had started off with carbonized paper as
Speaker 1: the filament. So this is the stuff folks would use
Speaker 1: to produce copies from one document. You would have your
Speaker 1: primary document and that would be on the top of
Speaker 1: a stack. Right below your primary document would be a
Speaker 1: sheet of carbonized paper that is paper coated with carbon
Speaker 1: on one side the site that's face downward from the
Speaker 1: top page. And then the next layer would be a
Speaker 1: blank sheet of paper that would be your copy that
Speaker 1: you'd be creating. So if you wrote on the top document,
Speaker 1: it would put enough pressure on this carbonized paper to
Speaker 1: leave an imprint on the blank sheet below that, and boom,
Speaker 1: you get two documents for the effort of making one. Now,
Speaker 1: you could actually do more layers of carbonized paper than
Speaker 1: blank sheets, but as you go down the layers, the
Speaker 1: pressure that is being put on the paper is decreasing,
Speaker 1: so unless you're being super heavy handed with your writing,
Speaker 1: the bottom copies will be much more faint than the
Speaker 1: upper ones would be, so you have a limit to
Speaker 1: how many copies you can produce through this method. Anyway,
Speaker 1: Swan was using carbonized paper as his filament, so he
Speaker 1: was connecting pieces of carbonized paper to a pair of electrodes,
Speaker 1: and he encased the whole thing in glass and attempted
Speaker 1: to create a vacuum inside the glass and then zap
Speaker 1: the heck out of the paper using the electrodes. The
Speaker 1: paper would heat up to the point of glowing, but
Speaker 1: the lack of oxidizers in the glass meant it wouldn't
Speaker 1: catch fire, except the Swan couldn't get a perfect vacuum
Speaker 1: seal in. The carbon paper didn't last very long, nor
Speaker 1: did it give off much light, so it wasn't really
Speaker 1: a practical filament for an incandescent bulb. It worked in
Speaker 1: the sense that it would glow, but it wasn't bright
Speaker 1: enough and it didn't last long enough for it to
Speaker 1: have any practical use. So Swan wanted to find something
Speaker 1: else to serve as the filament in his incandescent bulb.
Speaker 1: He was also experimenting with some other stuff like nitro cellulose.
Speaker 1: This stuff is highly flammable, so flammable that at one
Speaker 1: time it was being used as propellant for firearms, and
Speaker 1: it was called gun cotton back in those days. Well,
Speaker 1: Swan figured out that he could push nitro cellulus through
Speaker 1: like a mesh with very small holes in it, and
Speaker 1: the nitro cellulus would form fibers as a result, kinda
Speaker 1: like one of those playto playsets where you push down
Speaker 1: on a lever and it squeezes your play doo through
Speaker 1: a grid of holes, so you can make I don't know, dayglo,
Speaker 1: pink spaghetti or what. Well what Swan did the nitro cellulose,
Speaker 1: he also tried with carbon. He took carbon and in
Speaker 1: the form of cotton fibers. In this case, he treated
Speaker 1: the cotton fibers with sulfuric acid and then he pressed
Speaker 1: this solution through a screen with tiny holes in it,
Speaker 1: and on the other side of the screen he ended
Speaker 1: up with carbon fibers, and he could curl those fibers
Speaker 1: up to make tight spirals, which would increase the amount
Speaker 1: of material that he could fit between a pair of electrodes.
Speaker 1: And the carbon fibers, when used as a filament, produced
Speaker 1: better light than the carbon paper version he had been
Speaker 1: relying on and his process for making carbon fiber would
Speaker 1: become a standard. There are chemists and labs today who
Speaker 1: essentially use the exact same approach, though things get way
Speaker 1: more complicated when you're talking about mass engineering. For you,
Speaker 1: big industrial uses of carbon fiber. Now we're going to
Speaker 1: take a quick break. When we come back, we'll talk
Speaker 1: more about what makes carbon fiber special, but first let's
Speaker 1: hear from our sponsors. Okay. As smart as smarty pants
Speaker 1: Swan was, he wasn't able to see the potential mechanical
Speaker 1: applications of carbon fiber. He was just using it as
Speaker 1: an incandescent bulb filament. But he had no way to
Speaker 1: know that his material, if woven properly and combined with
Speaker 1: other stuff, could be strong, lightweight, and perfect for futuristic
Speaker 1: applications like the aerospace industry. Silly Swan not to anticipate
Speaker 1: all those uses back in the mid nineteenth century. Now.
Speaker 1: In fact, carbon fiber would kind of go into hibernation
Speaker 1: for many decades because there just weren't any practical uses
Speaker 1: for it or any real way to produce it at scale.
Speaker 1: It re emerged in nineteen fifty eight when a physicist
Speaker 1: named Roger Bacon produced carbon fiber and discovered that if
Speaker 1: constructed properly, it would be a really stiff, really strong,
Speaker 1: and extremely lightweight material. But it was super expensive to
Speaker 1: produce due to the time and effort involved, and the
Speaker 1: small amount of output you would get meant that there
Speaker 1: wasn't much you could do with it, so there was
Speaker 1: no commercial use for it just yet. But he was
Speaker 1: showing that this material had promise and that people would
Speaker 1: likewise start to pour money into improving manufacturing processes to
Speaker 1: make it practical. The evolution of those processes happened mainly
Speaker 1: in the nineteen seventies. Scientists in different parts of the
Speaker 1: world found new ways to produce carbon fibers. Some of
Speaker 1: those would be suitable for high heat applications, such as
Speaker 1: in the aerospace industry, where you might need to radiate
Speaker 1: heat outward from an engine before you get to a
Speaker 1: point where that's no longer your concern. Others would be
Speaker 1: suitable for more terrestrial uses. The eighties and nineties proved
Speaker 1: to be a boom era for carbon fiber research and development,
Speaker 1: as engineers recognized the material as being a good candidate
Speaker 1: for various applications, particularly in the space industry. Where there
Speaker 1: is a real need to create materials that are very strong,
Speaker 1: but you also want to cut way back on weight
Speaker 1: as much as you can in order to reduce the
Speaker 1: amount of energy you need to launch the stuff off
Speaker 1: this rock in the first place. So carbon fiber would
Speaker 1: become a really strong candidate for lots of space based applications. Now,
Speaker 1: as I mentioned earlier, carbon fiber has some really cool properties.
Speaker 1: It is really strong and really light. In fact, it's
Speaker 1: five to ten times stronger than steel, depending upon which
Speaker 1: source you're reading and the method of production for carbon fibers,
Speaker 1: and the specific type of steel you're talking about, and
Speaker 1: what you're actually looking at. So saying it's stronger than
Speaker 1: steel has really a simple answer to a complex situation,
Speaker 1: and it does mean that we need to spend a
Speaker 1: little bit more time to talk about material strength and
Speaker 1: what that actually means. So essentially, we quantify a material
Speaker 1: strength by examining how much stress or strain it can
Speaker 1: withstand before the structure we're looking at deforms to a
Speaker 1: point that when we remove the stress, it will not
Speaker 1: go back to its original shape. So, in other words,
Speaker 1: if you were to bend a bar and then you
Speaker 1: stop applying force, to the bar and the bar stays bent,
Speaker 1: you have exceeded the material strength of that bar. And
Speaker 1: if it pops back into its regular bar shape, then
Speaker 1: you did not exceed the material strength of that bar.
Speaker 1: There are different kinds of stresses that you can apply
Speaker 1: to materials, So when we say something is strong, we
Speaker 1: actually have to think about in what context. So again,
Speaker 1: let's talk about it having a short pipe. Now it's
Speaker 1: made out of whatever, it doesn't matter. We're just talking
Speaker 1: about the types of stresses you could put on this pipe.
Speaker 1: So let's say that you were to grip either end
Speaker 1: of that pipe and you were to pull in opposite directions,
Speaker 1: trying to allow lung gate the pipe. You're putting tension
Speaker 1: on it. This is the test for tensile strength of
Speaker 1: the pipe. How well does it hold up to stresses
Speaker 1: that attempt to elongate the material. And once you reach
Speaker 1: the point where you have exceeded that material strength, that
Speaker 1: tensile strength of that material, does it rip apart? Does
Speaker 1: it shatter? What happens? Now? What if instead of pulling
Speaker 1: on either end, you were pushing inward on either end
Speaker 1: of the pipe. You're trying to compress the pipe, You're
Speaker 1: squeezing the material. In other words, typically most materials have
Speaker 1: a high compressive strength compared to tensile strength, like a
Speaker 1: higher one. There are some elements at play here that
Speaker 1: can lead to other complications, Like, yes, it may be
Speaker 1: that it can withstand compression and it doesn't really compress
Speaker 1: beyond a certain point, but it might buckle, right, So
Speaker 1: there are other elements you have to look at when
Speaker 1: you're testing compressive strength. Then you've got sheer strength. Now,
Speaker 1: not sheer as an sh ee r strength. I'm talking
Speaker 1: about sh ea r strength like a pair of shears,
Speaker 1: because scissors effectively put this kind of stress on a material.
Speaker 1: So a shear stress is one in which the stress
Speaker 1: on either end of the material is parallel to each other,
Speaker 1: but they're in opposite direction. So if you think of scissors,
Speaker 1: like when the blades of scissors are coming together, one
Speaker 1: blade moving down, the other blade moving up, it is
Speaker 1: putting that kind of pressure on the material that you're cutting. Right,
Speaker 1: the one blade is moving up, one blade is moving down,
Speaker 1: so they are parallel to each other, but they're moving
Speaker 1: in opposite directions. And if you apply that kind of
Speaker 1: stress to a material, you can find out how resistant
Speaker 1: it is to shear stresses. So this is also called
Speaker 1: torsional loading. Right, You're at a torsional load to the material. Now,
Speaker 1: comparing materials against each other isn't always as simple as
Speaker 1: saying one is stronger than the other. One material might
Speaker 1: have greater tensile strength, meaning it could withstand elongation better
Speaker 1: than another material could in the same sort of situation.
Speaker 1: But maybe that first material can't hold up to the
Speaker 1: same sheer stresses that material two can withstand. You know,
Speaker 1: like some Facebook relationship status is it's complicated? Just does
Speaker 1: Facebook actually still have its complicated as a relationship status?
Speaker 1: Is anyone still on Facebook? Can I get a check
Speaker 1: on that? Anyway? Let's get back to carbon fiber. I
Speaker 1: think one way we can look at this is to
Speaker 1: think of strength in comparison to some other component and
Speaker 1: then compare two different materials. So in this case, we'll
Speaker 1: say strength to weight ratio. How strong is something compared
Speaker 1: to how much which it weighs. If we do that,
Speaker 1: if we look at it as strength to weight, carbon
Speaker 1: fiber is way stronger than steel. If you have a
Speaker 1: pound of carbon fiber and a pound of steel and
Speaker 1: they both have been made into some sort of you know, structure,
Speaker 1: the carbon fiber is going to be technically stronger than
Speaker 1: the steel is, and that's because steel is a really
Speaker 1: super dense material. So depending upon the application, a lightweight
Speaker 1: carbon fiber structure might be the way to go. For example,
Speaker 1: if you wanted to create a resilient helmet for football
Speaker 1: players I'm talking about American football here, well you would
Speaker 1: probably want to go with carbon fiber, not with steel,
Speaker 1: because I'm pretty sure no football player wants to wear
Speaker 1: a big steel helmet out on the field. But a
Speaker 1: lightweight helmet made with carbon fiber, that's a different story. However,
Speaker 1: if we were to instead look at strength compared to volume,
Speaker 1: the story is different. I watched a video from Crazy
Speaker 1: Hydraulic Press that compared stuff like acrylic fiberglass, aluminum, or
Speaker 1: aluminium if you prefer brass, titanium, steel, and carbon fiber
Speaker 1: to a hydraulic press test. The video has all of
Speaker 1: these materials made in the same simple shape a rectangular rod,
Speaker 1: so you know, it's like a rod, but it's squared off,
Speaker 1: it's not a circular rod, and it's the exact same
Speaker 1: dimensions for every single material, same length, same with you know,
Speaker 1: So that way you've got different substances, but they all
Speaker 1: are making rods of the exact same size from each substance.
Speaker 1: And that means that when you put the rods next
Speaker 1: to each other, the carbon fiber rod is going to
Speaker 1: weigh a lot less than the steel rod will, right,
Speaker 1: because steel is way more dense, it's heavier, it's gonna
Speaker 1: have more mass, even though the physical dimension of the
Speaker 1: two rods will otherwise be identical. Right, And if you
Speaker 1: put these two different rods to the test, the steel
Speaker 1: one's likely to hold up better because by volume, steel
Speaker 1: is the stronger material. If you look at weight, carbon
Speaker 1: fibers the stronger material. Like I said, it's complicated. And
Speaker 1: for the record, in the video I watched, the carbon
Speaker 1: fiber rod had a mass of fifteen point two grams
Speaker 1: and the steel rod had a mass of seventy six
Speaker 1: point eight grams. If we were to convert that to weight,
Speaker 1: and let's say we just go with pounds just to
Speaker 1: make it silly, then the carbon fiber weigh just point
Speaker 1: zero three pounds. The steel rod weighed point one seven,
Speaker 1: so way way more than the carbon fiber rod. And
Speaker 1: in the video they set the rods lengthwise across two prongs,
Speaker 1: metal prongs, and they use a hydraulic press to apply
Speaker 1: stress down across the length of the rod, like to
Speaker 1: push down right in the middle. So it's sort of
Speaker 1: like if you were to take a branch and try
Speaker 1: to break it in half across your leg. The carbon
Speaker 1: fiber rod broke when the press hit seven hundred and
Speaker 1: forty kilograms of weight at that point of the rod,
Speaker 1: and the steel held out till three thousand, eight hundred
Speaker 1: seventy kilograms. So again, carbon fiber seven hundred and forty,
Speaker 1: steel threey, eight hundred and seventy. But the story would
Speaker 1: be totally different if instead of volume, we were going
Speaker 1: by weight. If you had fifteen point two grams of
Speaker 1: carbon fiber and fifteen point two grams of steel, you
Speaker 1: would see that the carbon fiber would hold up way
Speaker 1: better because that would be a very small steel rod,
Speaker 1: very thin, and it would deform much faster than the
Speaker 1: carbon fiber would. And I'm going to talk more about
Speaker 1: carbon fiber, but we do need to take another quick
Speaker 1: break to thank our sponsors. We'll be right back to
Speaker 1: talk a bit more about what carbon fiber is used
Speaker 1: for and how it's used. Because it's not as simple
Speaker 1: as just making a frame out of carbon fiber. But
Speaker 1: we'll talk about that in just a moment. Okay, before
Speaker 1: the break, I talked about how carbon fiber is not
Speaker 1: just used as pure carbon fiber and stuff. In fact,
Speaker 1: we're usually talking about carbon fiber that is bonded to
Speaker 1: some other material, and carbon fiber access kind of like
Speaker 1: a reinforcing layer. So I like to think of it
Speaker 1: as similar to iron rebar that's inside a concrete structure,
Speaker 1: because the carbon fiber is providing strength and resilience, but
Speaker 1: it doesn't make up the totality of say the football helmet,
Speaker 1: for example, you have a binding agent in there. Typically
Speaker 1: you're using something like plastic and you're reinforcing it with
Speaker 1: carb fiber. So, to put it in another way, steel is
Speaker 1: really hard stuff. It's also really heavy, and it's challenging
Speaker 1: to mold steel into complicated shapes. We can do simple
Speaker 1: shapes pretty easily, but if you want to do something
Speaker 1: like a really a complex curve, maybe multiple curves in
Speaker 1: a single panel, it's hard to get steel to take
Speaker 1: that shape and not have it be an exorbitantly expensive process.
Speaker 1: But using a technology like injection molding and a material
Speaker 1: like plastic, you can create all sorts of wild shapes,
Speaker 1: and plastic is way lighter than steel, but of course
Speaker 1: it's nowhere near as strong. So combining plastic with carbon
Speaker 1: fiber can provide the strength you want, the weight you want,
Speaker 1: and the shape you want. Now, let's talk about what
Speaker 1: happens when carbon fiber fails. That is, when you apply
Speaker 1: a stress that exceeds the material strength of carbon fiber,
Speaker 1: and you're doing this to a structure made out of
Speaker 1: carbon fiber. Unlike some other materials, carbon fiber will not
Speaker 1: remain permanently deformed if a stress exceeds its material strength. Right,
Speaker 1: Like we were talking about the classic iron bars example
Speaker 1: of bending an iron bar, Well, you can bend an
Speaker 1: iron bar and it will stay bent, but that doesn't
Speaker 1: happen with carbon fiber. Instead, as dragon plate carbon fiber
Speaker 1: composites puts it quote, it will fail suddenly and catastrophically
Speaker 1: end quote. So in other words, once you go past
Speaker 1: the stress limit for carbon fiber, it's all over. You
Speaker 1: don't end up with a dent that can be hammered
Speaker 1: out later. You end up with shattered material or splintered material.
Speaker 1: To this day, carbon fiber fabrication is really expensive and
Speaker 1: it's complicated. When you look at a carbon fiber frame bicycle,
Speaker 1: for example, you're not looking at something that's made out
Speaker 1: of pure carbon fiber. You're really looking at a compound
Speaker 1: or a composite rather made out of material like plastic
Speaker 1: that has carbon fiber sandwiched inside of it to provide
Speaker 1: rigidity and strength. It wouldn't make any sense from an
Speaker 1: economic standpoint to go with a pure carbon fiber frame
Speaker 1: to replace, like I don't know, the chassis of an automobile,
Speaker 1: for example. You could go with a compound or composite
Speaker 1: that uses carbon fiber, and you would end up with
Speaker 1: a chassis that could be as strong as a steel chassis,
Speaker 1: but much much lighter, which ends up going to it's
Speaker 1: going to have a big effect on things like fuel economy,
Speaker 1: right because the engine's not going to have to move
Speaker 1: a vehicle that's nearly as heavy if the components are
Speaker 1: made from carbon fiber as opposed to steal. If you
Speaker 1: did go full carbon fiber, you would run into lots
Speaker 1: of problems. One would be the price tag because it
Speaker 1: would just be exorbitantly expensive. But also carbon fiber is
Speaker 1: not the perfect solution to all challenges. It's just a
Speaker 1: solution for certain engineering needs. Like there are components within
Speaker 1: vehicles that undergo a lot of different stress, right, not
Speaker 1: just tensile or compression, but also you know rotational that
Speaker 1: tortionial force can be a part of it. And in
Speaker 1: some of those applications a carbon fiber composite might shatter,
Speaker 1: whereas in other applications it's the carbon fiber composite is
Speaker 1: a perfect solution. So yeah, you have to pick and choose.
Speaker 1: You don't have just one material that's good for everything. Now,
Speaker 1: this brings us up to the tragedy of the Titan submersible.
Speaker 1: As we all know now, the Titan had a catastrophic
Speaker 1: failure that resulted in the implosion of the vehicle deep
Speaker 1: in the Atlantic Ocean. Authorities have now salvaged some of
Speaker 1: the wreckage and we can expect a full investigation to
Speaker 1: determine what was the point of failure, if it is
Speaker 1: in fact possible to determine that. Now, there's a chance
Speaker 1: that the culprit here is the carbon fiber hull, which
Speaker 1: wasn't totally carbon fiber. The end caps were made out
Speaker 1: of titanium, but the body of the submersible was carbon
Speaker 1: fiber or a carbon fiber composite. It's possible that the
Speaker 1: carbon fiber composite failed to hold up under the massive
Speaker 1: pressure that was exerted upon it by the sea. You know,
Speaker 1: as you get into those depths, that's a lot of
Speaker 1: weight that's pushing down on you. That pressure is incredible.
Speaker 1: It could also turn out that a totally different part
Speaker 1: of the submersible was to blame. One potential culprit could
Speaker 1: be the epoxy that actually bound the carbon fibers together. Remember,
Speaker 1: carbon fiber typically ends up being part of something else,
Speaker 1: like sandwiched in with other materials, and the epoxy was
Speaker 1: what kept the carbon fibers in their shape in the
Speaker 1: proper alignment. So maybe that epoxy, after multiple and prolonged
Speaker 1: exposure to sea water, degraded. We don't know yet. Still,
Speaker 1: the use of carbon fiber at all as a submersible
Speaker 1: material made it a little confusing for me. As we
Speaker 1: have covered, a big advantage of carbon fiber is its
Speaker 1: strength to weight ratio, and so it's really really good
Speaker 1: for applications where you want to limit weight as much
Speaker 1: as you can while not giving ground on strength. Right,
Speaker 1: you want something to be strong but light weight every
Speaker 1: pound counts. So again, when we look at the space industry,
Speaker 1: it makes perfect sense. You want materials that are as
Speaker 1: strong as they can be while still being light weight.
Speaker 1: Steel is strong, but steel's really heavy. So if you
Speaker 1: can make it out of something else that's resilient and
Speaker 1: tough like steel is, but is much lighter, that can
Speaker 1: make a lot of sense. But when it comes to submersibles,
Speaker 1: weight is not necessarily your primary concern. I mean, you
Speaker 1: don't want it to be so heavy that there's no
Speaker 1: way for you to lift it back out again. But
Speaker 1: you want really whole integrity. That's your main concern, not
Speaker 1: how heavy the submersible is. Most deep sea vehicles make
Speaker 1: use of steel, titanium, and aluminum rather than carbon fiber
Speaker 1: when it comes to what their pressure holes are made
Speaker 1: out of. Also, you know, there hasn't been that much
Speaker 1: research into how carbon fiber holds up under deep sea pressure,
Speaker 1: which means we don't know what we don't know. We
Speaker 1: have a big gap in our knowledge. And that was
Speaker 1: one of the big criticisms directed at ocean Gate, the
Speaker 1: company behind the Titan submersible, that the company had rushed
Speaker 1: through the process of making a submersible with a carbon
Speaker 1: fiber hull without first going through really rigorous testing to
Speaker 1: make certain that the carbon fiber hull was appropriate for
Speaker 1: the use that they had in mind for the titan
Speaker 1: mainly to go down and view the wreckage of the Titanic. Now,
Speaker 1: we do know that titan had already made trips down
Speaker 1: to the Titanic in the past. This was not the
Speaker 1: Titans made in voyage where the catastrophe happened. It had
Speaker 1: gone down there before, so the submersible had proven to
Speaker 1: be deep sea worthy on previous trips, which means we
Speaker 1: really do need to get a more definitive answer after
Speaker 1: authorities have investigated the wreckage to try and figure out
Speaker 1: what actually happened. Where was the failure, because right now
Speaker 1: it's all still a big question mark. Was it the
Speaker 1: carbon fiber hull, Maybe, but maybe not. As for carbon
Speaker 1: fiber itself, that's going to continue to be a really
Speaker 1: important material in engineering, particularly for things like aircraft, you know,
Speaker 1: the aerospace industry, things like automotive industry, bicycles, anywhere where
Speaker 1: you want a lot of strength but you want to
Speaker 1: cut down on weight. That's where it's going to make sense,
Speaker 1: not in every application, because again carbon fiber doesn't work
Speaker 1: under every situation at the same level of reliability as
Speaker 1: steel or other materials like aluminum, So it's all dependent
Speaker 1: upon the specific application. This is not like one material
Speaker 1: solves all problems. And the reason why I keep hammering
Speaker 1: on that, I know I sound like a broken record,
Speaker 1: but the reason I keep doing it is because I
Speaker 1: find that a lot of science reporting oversimplifies and just
Speaker 1: says carbon fiber is lighter and stronger than steel. And
Speaker 1: while that might be true in some particular instances, it
Speaker 1: doesn't mean that carbon fiber should replace steel in everything
Speaker 1: that we rely upon for you know, from steel. So
Speaker 1: that's why I go on and on about this, because
Speaker 1: I think you have to look at it as a
Speaker 1: more complicated subject than that. Otherwise you're over simplifying to
Speaker 1: a point where you just start to make bad decisions.
Speaker 1: Now I'm not saying that's what ocean Gate did in
Speaker 1: this case, but based upon a lot of the criticisms
Speaker 1: I've seen, it sounds as if Stockton Rush, the founder
Speaker 1: of ocean Gate, he was aboard the Titan submersible when
Speaker 1: it imploded, that perhaps he was a little too gung
Speaker 1: ho in forging a path forward to go through the
Speaker 1: rigorous steps that are really necessary to do things like
Speaker 1: make certain that the approach you're using is safe and reliable.
Speaker 1: Could this have tragedy have been prevented. It's hard to
Speaker 1: say because the investigation hasn't been complete yet. Maybe there
Speaker 1: was some wild thing that happened that we didn't anticipate,
Speaker 1: that couldn't have been anticipated, and it turns out that
Speaker 1: nothing we would do or have done would have changed it.
Speaker 1: Or maybe it turns out that this was something that
Speaker 1: was avoidable. We just don't know yet. So carbon fiber
Speaker 1: is still really interesting material, still really useful for specific applications,
Speaker 1: and this could also lead into a deeper discussion of
Speaker 1: things like carbon nanotubes, which in itself that's a fascinating
Speaker 1: technology too. When you start getting down to the nanoscale,
Speaker 1: you really see some very interesting features of materials, including
Speaker 1: carbon and carbon nanotubes being a super cool area of technology,
Speaker 1: but one we've been talking about for a long time,
Speaker 1: and for some people it may just seem like it
Speaker 1: was one of those technologies that seemed like it had
Speaker 1: a lot of promise but never went anywhere. That's not
Speaker 1: the case. It has gone places. It's just that it's
Speaker 1: not as sudden as we would all like, because we
Speaker 1: as we know, the real way toward the future is
Speaker 1: marking the passage of time and that doesn't change. That
Speaker 1: just keeps on creeping on, creeping on. All right, that's
Speaker 1: it for this episode about carbon fiber, a kind of
Speaker 1: overview of carbon fiber. And I hope all of you
Speaker 1: are well. I hope those of you in the United
Speaker 1: States had a fun and safe Fourth of July. I
Speaker 1: hope everyone to have a fun and safe Fourth of July.
Speaker 1: You just don't have a real reason to celebrate Fourth
Speaker 1: of July if you're not American, because it's related to
Speaker 1: our history. So hope you're all well, and I'll talk
Speaker 1: to you again really soon. Tech Stuff is an iHeartRadio production.
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