Small Tech, Big Deal

industrial revolution. So in the early twentieth century, technology like radios, televisions, and computers were all bigger because they had to be, because the internal components inside these technologies, the things that made these technologies work, were themselves much larger. That's why you would buy a television that had a tiny ten inch screen housed inside a cabinet large enough to be

a full piece of furniture. The invention of the transistor would lead to manturization, and in less than one years we would find ourselves holding a device in our hands that was vastly more powerful than the massive computers that took up entire floors of buildings back in the day. But what if we keep going down that path. What if we were to mantorize things even more? What if we could get technology down to a scale so small that it would be too tiny for us to see.

What have we conquered the nano scale? So in today's episode, I'm going to explain what nanotechnology is all about and how the idea evolved, and a bit about where we are now. We'll also talk about how stuff gets really weird when you get really small, which I think any toddler would attest to, but I mean, it gets really weird when you get really small. In fact, if you want to get super lucy goosey with the term nanotechnology, it gives us a chance to talk about those weird

things right now. But first a definition. Technically speaking, nanotechnology encompasses tech that is on a size scale of one d nanometers or smaller down to one nanometer. A nanometer is one billionth of a meter. A strand of human hair ranges between eighty thousand and one hundred thousand nanometers in width. So if you take one of your hairs because you can't take mine I'm bald, and you were to hold your hair and look at how wide that

strand of hair is, not how long? How wide? That's eight thousand to ten thousand times wider than what we're talking about here. In addition, we often think of nanotechnology today as being a branch of science and tech that is exploring the possibility of manipulating matter on the molecular or even atomic scale. The classic example of this in science fiction is the universal Assembler, a device that can construct macro sized objects atom by atom or molecule by molecule.

And we'll cover those in more detail a little bit later, but this is sort of how the replicators are on Star Trek are supposed to work. Right, You say t earl gray hot, and then the device takes all the atoms that are necessary to make that, puts them together right there when you're waiting, and boom, you have t on demand. But we don't have to wait until the twenty second century to talk about our work in nanotechnology. In fact, we can go back more than three thousand

years ago in China and talk about lamp black. Now, this material is a byproduct of burning oil, typically a coal based oil, and burning oil in a shallow and where you produce really heavy smoke was the typical production method for lamp black. You would use a collection pan that you would put near the flame, and the collection pan begins to accumulate very small particles of carbon they are deposited on that pan. Some of those particles are

around twenty nanometers in diameter. So the lamp black has a pretty phenomenal surface area to volume ratio, right, because the particles are very small, So there's more of the surface of the particle exposed to the air than there is under the surface. One way to think about this is if you have a gold brick that has a

certain amount of surface that's exposed to the air. Right, But if you were to make that gold brick into gold foil, right, if you were to flatten it out so that it's much much, much much wider, much much longer, but very e than well, now, way more of the surface of that gold is exposed to the outside world as a much larger amount of surface area compared to its volume. Well, that's kind of how things are on

the nano scale. Nanoparticles have way more surface area exposed to the world compared to their volume than stuff that's on the macro scale. All right, let's get back to lamp black. So because of this amazing amount of surface area, it became a very popular black pigment for inks. And paints. You didn't need a lot of it in order to be able to cover a surface. Well, if it's black,

then you could use that to be an ink. Right centuries later, this same sort of stuff, which we typically now call carbon black, is used in all kinds of applications, including printer toner. So even to this day we're using the same sort of stuff, these tiny, tiny particles of carbon. Way back in the three as in the four century Common era, some Roman artisan crafted a cup made out of glass. Now that in itself isn't incredibly special, but this particular cup had a really cool quality to it.

So let's say you had the glass sitting on a table and you placed an oil lamp in front of the glass, so it's between you and the glass. Then to you, the glass would appear to be green. But let's say you position the glass so that the light from the oil lamp was actually going into the glass rather than onto it. Well, now the glass would appear to be red. The color of the glass changes depending

upon how light hits it. Now today we call the glass by the name the Lakergus cup, and you can see the Lakergus cup if you ever go into the British Museum. Maybe not right now, but you know, things being what they are, but when things get better, you could see it there. That's where the cup is. It's called the Lakergus cup because the figure on the cup is that of King like Urgus. He's being dragged into

the underworld by the nymph ambrosia. So that's fun. So why does the glass change color and what does it have to do with nanotechnology? The answers had to wait more than fifteen hundred years before we really sussed it out. In n scientists used an atomic force microscope more on those later to examine the like Hurgis cup, and they found that this glass contained extremely tiny particles of copper, gold, and silver. The particles were in the nanoscale range, and

they were mixed in with the glass itself. The red light came from gold's absorption of light. The glass was a type of nanocomposite material. In the following centuries, glassmakers would experiment by adding different types of metals to glass mixtures to produce various colors of glass a k A stained glass. But while we were are able to grind stuff down to such a fine powder as to have

individual particles on the nano scale suspended in glass. It wasn't like we were building machines at that same scale. That would have been unthinkable. In fact, I would argue that before the transistor, most folks weren't really thinking about going small with technology. Before the electronic era, we were building mechanical systems, and generally the power of machines scaled

with their size. You could do stuff with gear ratios to help boost output without making an entire piece of technology bigger, but that only worked down to a certain point. In the early era of computers, even as we moved from the electro mechanical systems to pure electronic ones, the general thought was that the more powerful machines of tomorrow would be at least the same size, if not larger, than the behemoths of that era. Mantorization was something that

most people just didn't really anticipate. That, by the way, is something that we should keep in mind whenever we make any predictions about the future, is that frequently things we don't anticipate will end up being a much larger influence on the way technology develops than what is currently going on. So in the nineteen twenties, if you were predicting what the future of technology was going to be, You probably weren't thinking in terms of electronics. That was unanticipated.

And just like if we project out now, we say was it going to be like fifty years from now? If we're basing it on the technologies we're using right at this moment, chances are we're going to miss something because it's something we haven't early anticipated that's going to

change everything between now and then. Okay, anyway, in our history we get up to nineteen forty seven when William Shockley, Walter Britain, and John Bardine, among others, developed the first transistor in a T and T S research and development division that would be Bell Labs. The transistor could step in and do the job that was previously performed by larger components like vacuum tubes. Vacuum tubes are still in use today, but the transistors largely replaced them in many technologies.

So early transistors were large and impractical for any real application. They were, you know, a demonstration of a scientific principle, but you wouldn't actually use them for something like a radio. However, it did prove that the science underlying the transistors was sound, and it was only a matter of time before companies began to refine the technology and built smaller transistors and develop new manufacturing processes to do so at a scale

large enough for them to be actually be useful. We'll get to a famous observation that Gordon Moore made because of this particular trend in a little bit, but there's another person that I need to talk about first. In nineteen fifty nine, physicist Richard Feynman gave a presentation at the American Physical Society at the California Institute of Technology also known as cal Tech. He called the presentation There's

plenty of room at the bottom. It would retroactively become one of the foundational arguments in support of nanotechnology, the discipline and the pursuit of it. Now, it helps if we understand how things had developed by the time Feinman gave this talk. It took centuries for humans to develop technologies that allowed us to observe the world of the very small. From magnifying glasses to microscopes, we gradually peeled back the unknown, and we kept finding, to our amazement

that things could get even smaller. But light based or optical microscopes have fundamental limitations that are dictated by physics. It's not because the limitations of the materials we used. It's not that we couldn't find clearer lenses or anything. It's rather due to the fact that light waves themselves have limitations. Now, we can see stuff because light bounces off of it, and light waves are very short. They are tiny, but they're not as tiny as say, individual atoms.

Light waves are too big to reflect off of stuff as small as atoms and most molecules, and so no matter how good your optical microscope is, you're not going to be able to resolve images at that smallest scale just because you're using light. Typically you'd be relying on light with wavelengths of between four hundred and seven hundred nanometers. But that's way larger than stuff like proteins or some viruses,

and and way way larger than atoms. If you want to observe these smaller things, you got to shed your dependence on light. Back in nineteen twenty six, a German scientist named Hans Bush developed the first electromagnetic lens. This isn't the same sort of lens you would find in eyeglasses or a telescope or a microscope. Instead, it was a couple of electro magnets which could generate a magnetic field sufficient to direct a beam of magnetically charged particles.

This is the same sort of idea used in particle accelerators. In a particle accelerator, you've got these big, powerful magnets that create an extremely narrow channel through which charged particles can travel. They can't go outside of it because of these magnetic forces, and it guides the particles around a pathway so that they can collide with something else, such as a beam of charged particles that are traveling in

the opposite direction. Now, Bush proposed using the lens to make a microscope that would use electrons rather than light, and electromagnetic coils rather than a glass lens. He even patented a design, but he never constructed the electron micro scope. Max Knell, an electrical engineer, and Ernst risk a physicist, did build one in ninety one, though this early version wasn't able to produce an image that was at a higher resolution than what you could achieve with an optical microscope.

Those would come not that much longer down the road. However, the sample that you're looking at has to be inside a vacuum chamber, because air molecules would be like giant obstacles to an electron beam, and you wouldn't look at it through an eyepiece, you know, it's not like that type of microscope. Instead, you would capture the interactions of the electron beam with the sample you're examining on either

special photographic film or later on a monitor. So typically you would have a sensor and then the sensor would send data that you would then interpret visually through a monitor. By the time Feynman gave his presentation in the late nineteen fifties, electron microscopes could produce images at a much smaller scale than optical microscopes. What scientists had learned from

mathematics was actually beginning to bear out through observation. So sometimes we discover stuff because mathematically we understand that it has to be a certain way, even if we can't directly observe that way. That was kind of what was going on. We had sort of sussed out how the world had to be at that scale, and now we could actually directly observe it and learn even more. We appeared to be on the cusp of another major breakthrough.

The crux of Fineman's presentation was all about the manipulation and controlling of the world on the small scale. He started off by talking about the possibility of printing something like a full encyclopedia onto the head of a pen. Then he elaborated from there. He talked about the possibility of printing twenty four million books, which he estimated to be about the number of notable books ever written, and printing them onto the equivalent of thirty five sheets of

paper by making the print that tiny. His point was all about scale, that the scale of things we deal with in our everyday lives is gargantuan compared to what we could study with the help of powerful technologies like electron microscopes. He went on to hypothesize that if we were to develop a means of manipulating single atoms, you

could encode information using some form of simple system. He likened it to the dots and dashes in Morse code, and you could use it in a three dimensional space for each character, and it would measure five by five by five atoms to a bit of information, and even while using additional atoms for separation, you could print the equivalent of those twenty four million volumes on a particle

the size of a moat of dust. Feynman then goes on to suggest even more radical ideas, including using evaporation to reduce materials down to their smallest components, before then depositing those materials onto a substrate to build out wires and insulation and entire circuits. This way. Now, this is pretty similar to how we would make stuff like computer chips in the future, once we got all those technologies

down to work on the nano scale. Fineman goes on in his presentation to propose the possibility that we could build mechanical systems at the nano scale, using the example of an automobile, saying how would it be possible to build that on this very tiny scale? He argued that such a thing might be hypothetically possible, but it would require some big changes in automobile design, and a tiny

scale heat would dissipate much faster than at the macro scale. Again, you've got an incredible amount of surface area compared to volume, so an internal combustion engine wouldn't work. You wouldn't be able to get combustion. You would need some other sort

of reaction to provide the energy needed to do work. Ultimately, Feynman suggested we might find a way to build such small devices as to be able to assemble matter atom by atom, building with precision on an atomic level, and that could create countless possible applications, including being able to synthesize chemicals, which previously we had to do through chemical synthesis, which is not necessarily as precise and fascinating idea. I'll talk a bit more about it, but first let's take

a quick break. Fineman imagined a macro sized tool that could make essentially the parts to replicate itself, but on a much smaller scale. So imagine using a tool like a lathe to cut out all the parts for a smaller version of the lathe. Then you use this smaller lathe to cut out even smaller parts for an even smaller lathe, and so on, and then using these tiny tools to produce what Fineman called tiny hands to a symbol,

very small components. But then he said, we'd start to encounter some challenges that don't exist in any appreciable way on the macro scale. For example, once you get down to the molecular level, you begin to encounter forces that you just don't notice at larger scales, forces like the Vanderwall's forces. These are electric forces that attract neutral molecules to one another. They are pretty weak forces, but when you get down to the molecular level, the forces are

strong enough to cause issues. So he said, if you were to create the equivalent of a nut and bolt at the nano scale, you would find the Vanderwall's force strong enough that you would have trouble turning the nut like it would be difficult to tighten or loosen it because it would be clinging to the bolt due to the Vanderwall's force between the two. Now that's just the beginning.

Of course. When you get down to the nano scale, you start to enter into a world governed more by quantum mechanics then the classical physics that you and I encounter in our day to day lives. Weird stuff starts to happen. At least it's weird to us because we don't observe the world working in that way on our scale. So, for example, there's the truly weird phenomena of quantum tunneling. I'll try to explain this as best I can. So let's start with the classical world, because we generally have

a pretty good handle on that. Imagine you have a toy car, like a little matchbox car, and you've set up a ramp, and you probably understand that unless you push the toy car hard enough, it's not gonna make it up that ramp. It's not going to spontaneously go forward and climb that ramp. If you push too soft, then it's going to start going up the ramp and then roll back down. So the potential energy of the

ramp is a certain level. You have to give enough kinetic energy to the toy car so it can overcome the potential energy g represented by the height and the and the slope of the ramp. Now let's say we're doing something similar, except instead of a little toy car and a ramp, we've got an electron and an electrical field. If the energy of the electron is higher than the energy level of the electric field, the electron can pass

through it. But if the electric fields energy is higher, the electron will be repelled, just as the toy car would roll backward down the ramp if you didn't give it a hard enough push. But there's a tiny little problem. You see, at the quantum level, we're not talking in absolutes, we're actually talking in probabilities. Heisenberg's uncertainty principle explained that we'll never know the precise position and momentum of a

particle like an electron. We can only know a little bit about each and then we can work out the probability that a given sub atomic particle is in a certain position at any given time. So you can actually plot this out in a wave function. The peak of the wave corresponds with the most likely outcomes, the places where the electron is most probably going to be located at a given time, but there will be a small

chance that the electron will appear somewhere else. And if the wave function can actually overlap the entirety of the electric field, that means that there's a tiny little amount of that probability wave on the opposite side of the electric field where the electron could exist. The probability is very small, but it is there, which means it is possible the electron is on the other side of the

electric field. And if something is possible, then if you do that something enough times it means it will happen. It probably doesn't happen frequently. The probability tells us it won't, but if there is a chance it will happen sooner or later, it will. Now, there's a lot more to this stuff, like the discussion of evanescent waves, but while those make me wake up inside, they are also super

tricky to explain without visual aids. The important thing for us to remember is that if there is a probability that something will happen, if you have enough instances, you will eventually encounter that. And if that something means an electron suddenly appears on the opposite side of a barrier where it's not supposed to be, you gotta deal with that. So what this means for us in practical terms is that if we build stuff down at the nanoscale, we

have to worry about things like quantum tunneling. So imagine you've got an electric circuit with all the components small enough that the wave function of the electron means that sometimes the electron can be on the other side of gates or even in a totally different wire. Well that those gates and those wires are meant to control the flow of electrons. That's what circuits are. Circuits really are controlled pathways for electrical signals, and the important part there

is the control. If it's uncontrolled, you might as well not even have a circuit. So if electrons can just appear on the other side of gates as if those gates were open, or jump from one wire to the next, you've got a problem. You can't actually control electricity in a reliable way, you'll start to get errors. Now this is something microchip manufacturers actually have to deal with today

because they keep scaling down. The components on their chips were happidly in the five nanometer range at this point, which is smaller than I ever thought we would ever be able to go, and their talks about possibly getting as low as three nanometers or beyond. But we really have to answer some big questions about fundamental quantum mechanics problems in order to get there. So what the heck does this mean if we were to blow it out

to macro scale. Well, in our example with the toy car, it would mean that sometimes, let's just say you give the toy car a gentle push, most of the time it would just go a little bit up the ramp and then roll right back down. However, once in a blue moon, you would give it that tiny little tap and it would launch itself over the ramp. Other times you might give it a tiny little tap and it might actually move backward. Most of the time you would just see it hit the ramp and roll back. That

is a challenge. If you're building out a system that relies on predictability, and it turns out that your results are not always predictable, you've got an issue. Feineman's talk did not actually spark some sort of explosive interest in nanotechnology. It would take several decades before people would really go back to it as a sort of touchstone for the whole discipline. But other developments would play a part as well.

For example, in Gordon Moore's paper about quote cramming more components onto integrated circuits in the quote would serve as the basis for what we now call Moore's law. Gordy saw that the general trend was that a combination of factors can tribute to the doubling of components onto a

square inch of silicon wafer every two years. So if you could fit five thousand components on a square inch of silicon in nineteen sixty five, for example, by nineteen sixty seven, you could fit ten thousand components on that same square inch. His observations take into account not just technological advancements, but also the economic drivers. And if you've never gone through the paper, I highly recommend you check it out. The article is worth a read. You can

find it online for free. We typically dumb it all down these days to say that computers double in processing power every two years or so. But that's only a slice of what Moore was talking about. But how do we do this in the first place? How do we make machines twice as powerful so regularly? Well, a lot of stuff goes into it, But two really big factors are circuit architecture, that is, how designers lay out the

components of a circuit, and the size of the components themselves. Intel, which More co founded, has a design philosophy called tick talk that lays us out fairly well. In the tike phase, engineers figure out how to make smaller components from the predecessor generation microchip, but using the same architecture of that predecessor. So let's say you join Intel, They're just now going

into the tick phase of a processor. The previous processor was processor number twelve, So your job is to make processor number thirteen, and you're taking the architecture of twelve and you're essentially copying it, but you're making everything smaller, so you're able to fit more components on the same chip, but it's following the same general layout as Chip number twelve.

In the talk phase, designers optimize the architecture for these new smaller components so that they work as efficiently as possible. So with chip number fourteen, you take the size of the components you made for thirteen, but you lay them out in a new way so that they work as best as possible. When it comes to the next tick phase, it all starts over again. So Chip number fifteen is going to have the exact same architecture as fourteen, but

with even smaller components. Tick talk, tick talk. It's all about maniaturize, optimized, over and over until you hit some sort of fundamental barrier in physics that you are unable to work around. And we are headed towards that, but we keep on predicting the end of Moore's law and we haven't quite hit it. Yet, although you could argue that the length of time required has expanded over the years.

But yeah, so far we have not hit that fundamental limit in physics, and we now have microchips that have nodes or components that measure in the single digits of nanometers. But eventually we will hit that limit, and we'll have to come up with other ways to keep up with Moore's law or the spirit of Moore's law, or we'll finally have to admit that we've reached the limits of keeping up with that pace and we'll have to settle

for a less impressive rate of progress. No matter what, we're going to be looking at a different approach to computing, or things are really gonna plateau. Now we're going to skip ahead to the nineteen eighties because that's when we got the development of a technology that really let us get a look at stuff that was down on the atomic level. The electron microscopes had allowed us to resolve samples down to the nanoscale, but we couldn't quite do that on the atomic scale. Now atoms are less than

one nanometer in size. But our abilities got a big boost in one when Gerd Binnig and Heinrich Roarer developed what is called a scanning tunneling microscope. This microscope uses a metal wire that comes to an insanely sharp point

and it scans above the surface of a sample. The microscope applies an electric voltage to either the tip or the sample depends on the microscope, and what follows is a really complicated process, involving quantum mechanics, primarily the tunneling effect I mentioned earlier, and the piece of electric effect as well, and it gets way more complicated than I

can adequately explain or even understand. So rather than stumble through an explanation and likely getting a lot of stuff wrong along the way, I think it's just important that we understand. Using this process made it possible to image individual atoms for the first time. This was a monumental achievement, so much so that Bennig and Roarer would get a Nobel Prize for their work in the field just a

few years later. Imaging atoms brought us a step closer to being able to manipulate individual atoms, but to do that it would take nearly a decade. It was a night nine when Reese searchers at IBM found that if they worked in very low temperatures, and they used a scanning tunneling microscope. They cannot just image the surface of a sample. They could actually maneuver single atoms into a

specific place. The researchers used atoms of the element zenon, and they use the incredibly precise controls of this microscope to move the atoms so that they spelled out the letters I, B, M. Cute. Huh. They use thirty five atoms to do it. And think about this for a second. So let's let's imagine just a speck of dust, which is really tiny, right. That might measure just five microns across, and a micron is one millionth of a meter. But that tiny piece of dust is itself composed of hundreds

of quadrillions of atoms. I remember it. Atom is smaller than a nanometer, and a nanometer is one billionth of a me er. So when we talk about moving individual atoms around without disturbing the other atoms, it's at a level of precision that is impossible for me to imagine. I just can't work out how small that is. Between the invention of the scanning tunneling microscope and IBM S novel use of the technology to spell out its own name.

We get another innovation smack dab between the two. In nineteen eighties six, Christoph Gerber and Calvin Quait invented the atomic force microscope. I mentioned that earlier in the episode. This thing can image atomic sized particles in three dimensions, and it involves reflecting a laser off the end of a cantilever with a sharp point at the end of it.

As this moves across the surface of a sample, the attractive and repulsive forces acting on the cantilever change its position and angle relative to the laser, so that the laser reflecting off of it hits different parts of a sensor, and by interpreting that data, we can construct a three dimensional image of the sample. This might be hard for you to imagine. So let's say it's nighttime and you're holding a flashlight so that from your perspective, it's pointed

straight up into the sky. You're making a vertical line of light straight up, and you're walking and as you're walking along, you hit the gentle slope of a hill, so you start climbing. Your feet are still flat on the ground with respect to your position. A person standing far away can't see you, it's too dark, but they can see the beam of your flashlight, and they'll see as this beam of vertical light starts to tilt slightly as you hit that slope of the hill, they'll see

that it's it's turning a little bits, changing orientation. The steeper the slope you're walking on, assuming you can maintain flat feet on the ground, the greater deviation the person will see in that vertical line. Atomic force microscopes are kind of doing the same thing, but down on the atomic level. They're measuring how this reflected light is changing orientation based upon this very very sharp point moving across this tiny sample. Now, when we come back, i'll talk

about some of the disciplines involved with nanotechnology. Today. I left off talking about the atomic force microscope that was developed back in nine six. That same year, Eric Drexler's book Engines of Creation The Coming Era of Nanotechnology published. Now, this was the book that really brought Feynman's nineteen fifty nine presentation out of obscurity and then built upon it. This is the reason why nanotechnology has sort of the

narrative around it. It's largely due to Drexler's work. So in this book, Drexler expanded upon Feineman's ideas, going so far as to suggest we would be able to create universal assembler. And now we finally can explain what that's all about. So a universal assembler would be a device capable of building stuff out of individual atoms or molecules, and you could use these things to synthesize specific molecules

through physics instead of chemistry. Moreover, with enough assemblers, you could build macro sized objects, stuff that we could actually interact with in our own worlds. But then you think, if a speck of dust has a few hundred quadrillion atoms in it, how long would it take a universal assembler to make anything we would even be able to see. Well, one thing that could speed up this process would be to have universal assemblers that could build more universal assemblers

out of basic atoms. So the assemblers just start replicating themselves over and over. So you start off with two, and you get four, and then you have eight and sixteen and thirty two, et cetera. That exponential growth means that pretty soon you've got an enormous number of assemblers all over the place, and collectively, you would think they'd be able to construct stuff much more quickly. If they had a collective and coordinated a way of building stuff,

then you could produce things very fast. It's like having a three D printer that can make anything out of pretty much anything. Drexler also proposed a potential doomsday scenario based on this idea, and it's the so called gray Goose scenario. The idea is that universal assemblers would malfunction in some way so that they just keep making replicas

of themselves. They're making more universal assemblers, which then make more universal assemblers, and it starts to break down all other matter just to get the raw materials needed to make more universal assemblers, and the process gets faster as it goes on because you've got more of them. These tiny machines would disassemble anything that wasn't a universal assembler itself, and the creation we made would devour us all. For

the time being, this is purely a thought experiment. We are nowhere close to actually making something like this, so don't lose any sleep over it. And certain aspects of nanotechnology are older than others. For example, we've been making mixtures from nanoparticles of certain metals for a really long while. As I mentioned earlier in this episode, colloidal silver is a really great example. The word colloid comes from chemistry. It's a mixture that has very very tiny particles of

something suspended throughout some other substance. This isn't that different from the glass I talked about at the beginning of the episode. So silver has antibacterial properties. This is just true of that material. Even before humans really knew what bacteria were or that they were a thing, they developed a general understanding that silver could help ward off stuff like infection. Maybe that's why silver also plays a part in certain mythologies, such as the idea that you can

kill a werewolf with silver or some vampire. Our legends involved using silver to kill vampires might be the idea that silver wards off impurities as it were. Today, companies manufacture bandages and wound dressings with silver nano particles woven into them to help with healing and to prevent infection. Of course, people can take the antibacterial properties of silver

to extremes. There are folks who have taken courses of colloidal silver to treat all sorts of ailments, and this can have a particularly noticeable side effect because it can turn the skin a sort of bluish color. Silver compounds will build up in human cells and this is what causes that change in color. There's even a term for this condition, argeria. Take a look online for colloidal silver and blue skin and you're gonna see some interesting images. And I think that's one thing we have to take

away from the young discipline of nanotechnology. We're still learning how stuff works at this scale. If you listen to the smart Talks episode I did in which I spoke with Dave Turrek of IBM, you heard him talk about using high performance computing systems to simulate molecular interactions, all with the goal of figuring out treatments for COVID nineteen. Now, there are processes that we don't fully understand happening, and not just small scales in terms of physical size, but

also at small time scales. So we humans we measure time in seconds, minutes, and hours, but when you're talking about atomic and molecular interactions, you might need to look at changes that happen over the course of a few fempto seconds, and a fempto second is one quadrillionth of a second. We've got a lot to learn when it

comes to the nano scale. Some materials have radically different properties when you look at them on the nano scale, properties like electrical conductivity, or the materials melting point, or it's reactivity, it's chemical react ativity, it's fluorescence, uh, it's magnetic permeability. All of those can be very different. It's almost like a substance changes identities once you get it down to that size. Another one is toxicity. Toxicity is

another quality we have to take into consideration. It may be that something is completely harmless on the macro scale, like we would never have any problems if we came into contact with it classically, but if we encounter nanoparticles, those might interact with ourselves in such a way as to be toxic. So we have to really research this before we start making practical applications of nanotechnology, particularly in

the medical field. We're still years, if not decades, or maybe centuries away from building nanoscale assemblers, but we're taking advantage of stuff on the nanoscale all the time. For example, you've probably heard about carbon nanotubes, a truly interesting material that we have in fact made without knowing it for centuries. This stuff helps illustrate how different things can be on the nanoscale, though I guess again we shouldn't be surprised.

So carbon is plentiful stuff, and it can take lots of different forms. The two examples that you always hear about are it's the stuff that's in pencil lead, and it's also the stuff that's inside diamonds. The arrangement of carbon atoms determines the properties of the stuff at macro scale.

But it sure does seem wild to think that the same thing that's soft enough to serve as a way to write stuff down on paper can also be an incredibly hard substance capable of cutting through lots of other stuff just by rearranging the way the atoms bind with each other. So what's the carbon nanotube. Well, you can start off with a sheet of carbon atoms just one atom thick, So think of it as a very thin blanket made up of carbon atoms that are linked together

in a hexagonal pattern. We call this graphene. Now you roll up this graphing into a tube and you get yourself a carbon nanotube. But here's a really cool part. The direction in which you roll this material determines the properties of the tube. So again, think of it like a blanket. If you were to roll it from top to bottom, you would get one set of properties, but if you were to roll it on the diagonal, it

would be a different set of properties. So carbon nanotubes can be really strong but extremely light weight, So a lot of folks hope that it could be the secret to some really phenomenal technology in the future. For example, in the space industry, getting a really high strength, low weight material is incredibly helpful. You needed to be strong enough to withstand, you know, the rigors of launching stuff into space, and you also have to remember this space

is always, always, always trying to kill you. But you also want the material to be really light weight because that reduces the amount of energy you need to get the darn stuff off Earth in the first place. Carbon nanotubes have been suggested as a possible material for a tether for a space elevator. The space elevator concept is

kind of trippy. Essentially, you've got a weight or technically a counterweight, like maybe a space station, and it's out in space and it's tethered to the Earth that has anchored somewhere along the equator of the Earth, and this counterweight the space station would be way out beyond geo stationary orbit. That is, way the heck out there. Geo stationary orbit is around thirty six thousand kilometers the the International Space Station is just at four hundred eight kilometers,

so we're really talking deep out there. But the idea is that the centrifugal force on the tether would be equaled by the gravitational pull on the tether, and you would end up with a taught cable that could go up to the stars or at least out into a far orbit, and an elevator would be able to climb that cable, delivering payloads out into space without ever having to load it onto a rocket and blast the stuff

up there. Now, there are a lot of engineering challenges in the way of ever realizing this technology here on Earth, among them finding material strong enough to with stay and the crazy amount of force it would be under. Some folks hope that carbon nanotubes could be the answer to that. That's just one tiny example pun intended of a possible application for nanotechnology, but one that's really still far off

in the future. If it's a you know, at all a possibility, but In the meantime, countless scientists are learning more about what happens on the very small scale, which is great because it extends our knowledge about how the universe works, and it also gives us the opportunity to leverage that knowledge and fields like chemistry, medicine, material science, and robotics. Nanotechnology plays an important role, just not one in which we have very teeny tiny robots building stuff

atom by atom. We have done some molecular manipulation on that scale, but it's been far more meticulous and human controlled than the sci Fi scenario. Now, all of this is to say that a lot of the technologies that are marketed as nanotech are at best mis leading. I've seen robots that have been called nano robots, and they're pretty small, but they're not even crossing the micron threshold, let alone the nano scale, so I think that's not

really terribly accurate. There have been some interesting sensors and switches and things that are on the nano scale that you could argue fit into nano robotics, although it doesn't necessarily match what we classically think of as a robot, but it's still closer at least than these small but not you know, microscopic robots that I see marketed as nanobots all the time. I'm sure I'm gonna do a

lot more episodes about nanotechnology, including specific implementations. I mean, I didn't even get into Bucky balls in this episode, so you know, I've got to come back to it in the meantime. If you have suggestions for future episodes of tech Stuff, whether it's a specific technology, a company, a person in tech, maybe just a trend, let me know. Reach out to me on Twitter or Facebook the handle for both of those as text Stuff H s W and I'll talk to you again really soon. Y. Text

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