Welcome to tech Stuff, a production from iHeartRadio. Hey there, and welcome to tech Stuff. I'm your host, job and Strickland, I'm an executive producer with iHeart Podcasts and how the tech are you? So it is Friday, It's time for a classic episode, which means we dive into the tech Stuff archive and pull out an episode from our past to listen to. This one, originally published on June twenty eighth, twenty seventeen, is called The History of Electricity Heart one, which kind of spoils what we're going to be talking about in next week's classic episode, but you know, there's no gain around it. I hope you enjoy this classic episode. So first, let's define what electricity is, or rather, instead of letting me define it, let's use Miriam Webster, because that's kind of their job. Electricity is a fundamental form of energy, observable in positive and negative forms, that occurs naturally as in lightning, or is produced as in a generator, and that is expressed in terms of the movement and interaction of electrons. That's actually kind of a little simplistic. It's talking about the move of electrons. It's really more about the move of electric charge and not of electrons. Specifically, if you had some other carrier that was carrying electric charge, it would be more about the movement of that carrier. As it turns out, electrons are the naturally occurring negatively charged particles sub atomic particles that are concerned, especially with electronics. So it's understandable, but I just want to point that out that it's really more about electric charge and less about the actual sub atomic particles. Don't worry, even though we'll be talking a lot about electrons. I promise this show won't be too negative. I'm seriously done with pun for just a bit now. To further define electricity, it helps if we get some basic ideas established. Now, keep in mind these aspects of electricity were not understood for centuries. So when I go into the history of electricity, remember that for the vast majority of our experience working with and trying to understand electricity, we did not have any knowledge of the underpinning foundational physics. Right we were making observations and we were even building things that could take advantage of this stuff, but we didn't actually understand what it was doing or how it was working, which I always find really fascinating this idea that we can harness something without fully understanding what it is and how it works. But it's good for us, as in myself and you guys the audience, to understand some of these basics before we get too far into the discussion. Otherwise I have to keep interrupting the history lesson for science lessons, and then it gets kind of a little complicated. Some of that's gonna happen anyway, but I want to get the foundation out of the way. So the most important thing to remember here is that we're talking electric charge, and we want to make sure we can make sense of this. It's time to get current on our terms. So I guess that really wasn't the last pun I'll be talking about. So electric charge comes in two flavors, positive and negative, positive charge and negative charge. You're probably very familiar with this. On the sub atomic particle level, pot you know, we have our protons, those are positively charged. We have our electrons, those are negatively charged. Now, opposite charges attract one another in circuits. A carrier moves negative charges to a source of positive charge. So some sort of sub atomic particle needs to carry that negative charge throughout a circuit until it can get to the source of a positive charge. Because negative quote unquote wants to be with positive. It doesn't really want anything, it's just that's the natural tendency, right these for these two different charges to attract one another. Now, in practical terms, the carrier is an electron. So that's why we talk about electricity, it's why we talk about electronics. It's the subatomic particle that possesses negative charge. So if we do a basic electrostatic experiment where we take a block of wax and we rub that block of wax with some wool, we will build up an electrostatic charge. So what's happening is we are imparting a negative charge to the wax and creating a positive charge to the wool. So, in practical terms, that means the wax has a surplus of electrons and the wool has a deficiency of electrons. Effectively, you are rubbing some of the electrons from the wool onto the wax. That makes the overall charge of the surface of the wax negative. It makes the overall charge of the surface of the wall possi And if we create a pathway that electrons can follow from the wax to the woll. Then electrons will take that pathway pop back over to the wool and sort of repair that deficiency where that deficiency of electrons will be balanced out, where electrons will journey back over and rejoin, and they'll probably be a big party, you know, or at least a sub atomic one. And that's the basics for electric charge. So now we have to build on this foundation. There are three other basic concepts that we need to understand, and those are voltage, current, and resistance. Now these will be important throughout the discussion of electricity, particularly as people begin to get a deeper understanding of what was actually happening with electricity. Voltage is probably the trickiest one for people who aren't inclined toward electronics and electricity. It's all about potential energy, specifically the potential energy represented by a pair of different electric charges. So voltage is sort of like pressure. You can imagine it as a force that pushes electrons through a conductor, which is oversimplifying, but it's helpful when you imagine it that way. So voltage is the pressure in the system. The higher the voltage, the greater the pressure, the stronger that push is a low voltage has very little push, while high voltage has a whole lot of push, and we need voltage to make electronics work. Otherwise nothing is going to cause a current to flow through a circuit. You can also kind of think of it as potential energy in the form of as an analogy of kinetic energy. So let's say that you have a level surface upon which you've got a two little corrals of marbles. They don't really have any potential energy with respect to one another, they're on the same level. But let's say you raise one of those up. You tilt it and you raise it up, so the corral is still holding the marbles in. But now the marbles have potential energy because they're at a higher level than the lower marbles. And then let's say you were to connect a little slide between the top corral and the bottom corral and allow the marbles to roll down the hill. Well, this would be sort of like a copper wire connecting an area that has a surplus of electrons to an area that has a deficiency of electrons. It's allowing for the movement of those electrons. Now, in the case of voltage, we're really talking about electric potential. Here we're not talking about kinetic energy or potential energy that could be converted into kinetic energy. Is really just meant as an analogy. So when we talk about voltage, we talk about it with respect of two points on a circuit. So a voltage difference between two points on a single circuit and their potential difference really which we may also call a voltage. The potential difference between two points is measured in a unit called volts. No big surprise there. A volt is the amount of energy needed to force an electrical current of one ampier more on that in a second, through a resistance of one ome more on that in a second two at a particular temperature. Now, you can have a voltage between two points without having any connection between them, So you can have a voltage between two things that do not have an active pathway between the two. If the distance between the two points is decreased, then that electrostatic field that the voltage difference creates will intensify. If you increase the space between those two points, the electrostatic field will diminish. So distance plays a factor, not just the difference in voltage, so that covers voltage, but now let's talk about current. So technically the current is a flow of electrical charge, and we commonly think of it as the movement of electrons, but again that's an oversimplification. You can actually have a flow of positive charge and that would still be a current. If you add a flow of positive charge, that's technically a current. But when we're talking about circuits and electronics, we're really talking about electrons, not positively charged electrical charges, So we tend to simplify it and say it's the flow of electrons. Just keep in mind that is an oversimplification because electrons are the charge carriers of negative charge. Now, in a way, you could think of it as electrons are the messengers and the electric charge they carry is the message, and that's what's really important. But in practical terms, we can just simplify it to electrons. We measure current in ampiers and that gives us a sense of the intensity or quantity of a charge. So voltage is the force behind moving a charge, and amperage tells you how much charge is actually moving. And this can help if you start to imagine voltage as being a locomotive engine and the amperage as being a series of train cars. So a low amperage current you might think of as just being two or three train cars being pushed by a locomotive engine. But you might think of a high amperage as being a series of train cars like fifteen or twenty being pushed by that same locomotive engine. In both cases, the locomotive engine is putting out the same amount of force. It's just that in one case it's pushing a relatively small number of train cars and the other one that's pushing a larger number. But the amount of force that's using for both is the same. So that's the difference between current and voltage, or if you prefer amperage and volts. Now, current will get a bit more confusing when we start talking about the direction of flow, and that's thanks to a certain founding father of the United States. But I don't want to jump ahead. We'll get there. When we get there, I'll save that for a little bit later in this episode. Finally, we have the concept of resistance, and as the name suggests, this is the property of a material to resist the flow of electric charge. A material with a very high resistance is an insulator. It does not allow electric charge to pass through it very easily. You would have to use a great deal of energy to move an electric charge through that kind of material. A material with very low resistance is a conductor. It will allow electric charge to flow through relatively easily. Now, even conductors have resistance. You have to get to very low temperatures, like super frozen temperatures almost close to absolute zero to get to super conductivity where you have zero resistance and a conductor becomes an ideal or perfect conductor. But at other temperatures there's some resistance. You can get around that by making a cable thicker. Thin cables have a higher resistance than thicker cables, But that's kind of beyond what we're talking about here. We measure resistance in Ohms and Ohm. George Ohm, who is a physician who kind of figured all this stuff out, developed Ohm's law. Now that tells us that voltage is equal to current times resistance, or you could say current is equal to voltage divided by resistance, or that resistance is equal to voltage divided by current. It's this relationship between current, resistance and voltage that is inherent in electricity and electronics. Now, those basic concepts are the very foundation for all electronics. Now, obviously it gets more complicated and you can add in all sorts of different elements besides that, with like diodes and things of that nature. But I just wanted to get that covered as the basis for the conversation that follows. And now we're going to dive into a history lesson. So humans have known about electricity in some form for millennia fales of Melitas, And I know I'm mispronouncing that, So to all my Greek historians out there, I deeply apologize, but I have little Latin and less Greek. Along with my buddy Shakespeare. Anyway, he had noted that amber, the material amber, would attract light materials to its surface after being rubbed. So if you rubbed amber with a cloth and then held it toward feathers, for example, you had notice that feathers would have a tendency to be attracted to the amber. Now, later on we would understand that this is static electricity, this is building an electrostatic charge using amber. But this was more of an observation back in those times, and this is centuries before the Common era, and in fact, the word electricity comes from the last an electrom, which in turn comes from the Greek electron, which means amber. So when we talk about electrons, that means that's the Greek word for amber. And it's because of this initial well not even initial, but this early observation. I just thought that was kind of interesting, and you would eventually learn that a future engineer scientist named this whole process electricity in honor of this early observation. Now in nineteen thirty six, we're jumping ahead just to talk about another discovery about ancient civilizations. There was a railroad project that ended up excavating some ruins southeast of Baghdad, and they revealed what we have commonly referred to as the Bagdad batteries. These were vessels that appeared to have been designed specifically to generate electricity. At least that's one of the hypotheses about these these vessels. Some people disagree, but it's a very popular one. Now you probably have heard about this in some form of another or another. You may have even seen the MythBusters episode where they talked about this. The team in MythBusters talked about the possible applications for these so called batteries, which could include a thing that you would use in religious ceremonies, where you would have these metal coded vessels that if you were to touch them, you would create a circuit and you would allow electricity to flow through you, and that would create a tingling or numbing sensation in your hands, thus akin to some sort of mystical experience and thus being part of a religious experience. Or it could be that it was more of a practical approach toward something like electroplating, and I thought that was really cool. So let's talk about what electroplating is, because otherwise, you know, it doesn't really mean any thing to you. As the name implies, electro plating involves using electricity to cover or plate one material with another material. Typically you are plating one type of metal, not necessarily metal, but the early version of electro plating was metal, but one type of metal with a more precious metal. So the reason you might do this is to make really pretty expensive looking stuff without using too much of the actual precious material. So you might gold plate a copper bowl, for example, because you want the gold bowl. Gold is more precious than copper, but you don't want to actually have to go out and dig as much gold as you would need to build a gold bowl. So you want to plate the copper bowl with gold. That way, it looks exactly the way you want it to, but you didn't have to spend all that time and effort getting all that gold. In other words, we can thank the laziness and greed of human beings for some of the early advances as as far as electricity is concerned, So you might want to use electroplating to do that. We also use electroplating for other purposes, like putting rust resistant coatings onto stuff that otherwise would corrode. You can also use it to produce alloys like bronze and brass. But let's go back to electroplating. So let's say these ancient people were using the so called Baghdad batteries in order to electroplate gold onto copper. How would you do this, Well, first, you have to make sure that the copper is totally clean, because if it has any schmutz on it, the gold will not properly adhere to the copper and it'll flake off. So you typically would clean copper this way by dipping it in a solution that either is a really powerful alkaline solution or a very powerful acidic solution to truly clean it. Once you did that, you would then attach a conductor from the battery to the copper that you're playing on electroplating. So if it's a bowl, then you would want to make sure that the terminal, the proper terminal from the Bagdad battery is in contact with that copper bowl. Then you would put that whole thing, the copper bowl with the terminal into an electrolyte solution, which is in this case a gold based electrolyte, so you have gold particles within the electrolyte itself. Now, electrolytes, by the way, are materials that dissociate into ions when dissolved in a suitable medium, and become a conductor of electricity. So ions, of course our variations of atoms that have a net charge on them. They're not neutral. They have either a net negative or a net positive charge. So when you do this, you've got your gold ions in this electrolyte solution. You then put the electrodes together so that not together, but within the solution, and so that a current can pass through the electrodes. Allow the current to go through the electrolyte into the other terminal or the other electrode, and you've got a negative and a positive electrode. So when the current passes through the electrolyte, the electrolyte splits up and some of the metal atoms contained within the electrolyte are deposited on one of the two electrodes that you inserted into the electrolyte. So what's really happening is the metal atoms are ions. They hold that charge, they're attracted to the electrode that has the opposite charge and they attach to it. So if you have a negatively charged terminal and you have positively charged gold ions, that opposite attract rule still takes place, and the gold will plate onto the copper electrode or bowl in this case, and then you've got your gold plated copper thingam a jig, which is kind of cool. Now, there's some who put forth the hypothesis that perhaps ancient people's made other uses of electricity all the way up to even powering lights in ancient Egypt, but most scholars that I have consulted dismissed this as unrealistic. I haven't really seen much evidence to support this apart from some circumstantial evidence. Some supporters cite a hieroglyphic relief that shows what to our modern eyes appears to be an enormous light bulb. But the accepted interpretation of that hieroglyph seems to be that it's a lotus leaf with the figure of a snake on it, not a huge ancient light bulb. Still, it seems that there was at least some knowledge of the existence of electricity, if not what it actually could do or what it was. Now that's a trend that would last for centuries. In fact, we were making use of electricity well before anyone really knew what was going on with it. And again, to me, that is one of the phenomenal things about human history is when we come across these moments where people have figured out something or how to use something without really fully understanding why it is, that could be dangerous. Clearly, there were plenty of cases of that in the nineteen fifties with radiation, where people thought that radiation didn't have any particular harmful effects. You might have seen things about like using X rays in shoe stores so that people could see their feet through the shoes that they were trying on, and then only later did we realize that X rays are an ionizing form of radiation and that we probably should not or definitely should not have been doing that same sort of thing with electricity. We were putting it to use before we ever really understood what was going on there. But of course electricity isn't ionizing radiation, so it does have very different effects than radiation does. But what follows is a brief history of the developments that unfolded as very very smart people figured out what the heck electricity is. So in the fifteen hundreds you had an English physician and proto scientist named William Gilbert who began to experiment with magnets and static electricity. So he used loadstone, which is naturally magnetic iron ore, and he published his work in sixteen hundred under the title d Magnetae or Magnety. It's magneto but with a knee. He was able to describe magnetism and static electricity as distinct phenomena, though he wasn't really sure what was actually causing it. His hypothesis was that there was some sort of fluid or humor, as in the various humors of the body. There was another prevailing physical theory at the time, and that this was the cause of attraction with static electricity, and that if you rubbed amber, what you were actually doing was removing some of that fluid from the amber, which created a hole or like a vacuum around it, and this is why light objects would become a tra to the amber. He called it effluvium and described it as an electric effect. In sixteen sixty, an inventor named Auto von Geirica built a machine using a globe made of sulfur, and if you rubbed the globe as it turned, you could build up a charge, an electrostatic charge, causing it to attract small light objects, such as feathers or scraps of paper. Gherica also observed that his invention would cause a spark if you rubbed the globe for long enough. You could then touch something metal like a brass knob, and see a spark fly between the electrostatically charged object and the grounded piece of metal. Stephen Gray, another English scientist, observed in seventeen twenty nine that some stuff doesn't conduct electricity at all, so he thought some materials would allow the fluid of electricity to flow through, and other materials would hamper the flow of this fluid. Electricity would which is sort of true when you get to electrical resistance, only we're not talking about a fluid really. Later that century, Dutch inventor's Pietr von Mussen book and evolved von Kleist created what we now call the Leyden jar, and there are actually two variations on basic Leyden jars, which store electrostatic charges. They're essentially capacitors, So you build up an electric static charge in this thing, and then when you touch the the charged component, you allow that electrostatic charge to discharge to spark, so they release all of that charged energy in an instant. Unlike a battery, which releases uh well, which which creates the voltage difference and allows for electric electric current to flow over time, a capacitor releases it in a in a moment. The There are two basic versions of the Leaden jar, and the first one uses a metal container inside which you have a glass vessel nestled inside that metal container, and inside the glass vessel you have a second metal container nestled inside that. So it's kind of like a sandwich where the bread is metal container and the bread and the meat inside is glass. I don't recommend eating that sandwich, it would not taste good and probably hurt you. But it was that layer metal glass metal, and you would then also have a rod of metal that would extend up from the base of that interior lining. So imagine like a column rising up from that internal metal cup inside the glass vessel, which in turn is inside a larger metal vessel. The second variation has a metal vessel filled with a conductive fluid like water that's got a salt dissolved in it. One or on its own will conduct electricity as long as it has some impurities in it, but you can make it conduct electricity more effectively by adding or doping the water with some of those impurities, and it would have a metal rod sticking out from the water. Now, both versions would allow you to do essentially the same thing, which is store up that electrostatic charge. And you do this by building up an electric static charge in something else. So you might take some amber, for example, and rub the amber. Then you would bring that into contact with that metal bar that's extending upward from the jar. That would introduce a charge to one plate in this capacitor, and that would create the opposite charge in the opposing plate. In this case, that exterior metal casing. You would need to ground the outer metal case, which you could just do by touching it yourself, or you could run a wire from the exterior metal case to the ground or to a metal pipe. And when you create a pathway between the plates by touching the charge grod, it creates a spark as the charge is able to equalize, and that could be a significant shock, depending on how much you've built up inside this Leyden jar to the point where it could really hurt or possibly do serious damage. Both Kleist and Muschlenbrook had shocking experiences with their respective Leyden jars, and neither was really sure exactly what was happening. Now we've got a lot more to talk about with the early discoveries surrounding electricity. But before we get a charge out of all that, let's take a quick break to thank our sponsors. All right, We're up to seventeen fifty two, and that's when we revisit the great founding father I had mentioned earlier, Benjamin Franklin. That's when we got the legendary experiments that Franklin conducted. He was friends with a scientist named Peter Collinson over in Europe, and Collinson had sent Franklin an electricity tube. Franklin, like his predecessors, thought electricity was a type of fluid, and he hypothesized that lightning itself was an electric spark, very much like the kind a leaden jar could produce if you built up enough of an electrostatic charge, and thus charged forces would cause a lightning strike. And he further hypothesized that you could use a metal rod to draw lightning to a specific location, which could end up saving structures from being struck by lightning. So if you had a house and it got hit by lightning back in those days, your house would very much be damaged, possibly burned down as a result. So he thought, well, maybe you could draw lightning away using long metal rods. But the problem was he couldn't build a metal rod tall enough to dwarf the structures. He thought that he was going to have to build something that could almost reach the skies themselves, which made it too big of a challenge, so he came up with this idea of using a kite instead. Meanwhile, over in France, Thomas Francois d'alabard decided to put Franklin's ideas to the test. He actually constructed a large metal pole to try and conduct electricity and declared that Franklin was absolutely right that, in fact, that metal rod does draw lightning. But this news didn't travel back to America that fast. I mean, it took a really long time for information to go from one place to another, so Franklin was unaware that his hypothesis had proven correct. So that same year, Franklin reportedly conducted his experiment using a silk kite with a key tied to the silk kite down to the string, and as legend goes, he flew the kite up during a thunderstorm until the key drew lightning to it, and then used that key to charge a Leyden jar. So the electric charge in the key was then transferred to a leaden jar, which again holds electrostatic charge. Now, I say reportedly because Franklin's writings never outright said that that was what happened. He never specifically said that he himself had performed the experiment. Now, he did say that he did a simplified version of this plan and that it happened in Philadelphia, but it's unclear who was actually flying the kite at the time. And according to modern scientists, if Franklin had conducted the experiment as it has generally been reported, Franklin would have been toasted. He would have been fried scientifically speaking, So the general theory about this not scientific theory, but you general idea of what actually happened was that Franklin, if he conducted the experiment at all, was able to pick up an electrostatic charge by flying the kite near a storm, but that the kite was never directly struck by lightning. It just rather picked up a charge by being lightning adjacent. I guess, as you could say, all quibbling aside. By this time, it became established that lightning was in fact a really big spark. Therefore part of this concept of electricity. Franklin made practical use out of this knowledge by inventing the lightning rod. Now, the purpose of a lightning rod is to attract a bolt of lightning to the rod and then channel the electricity down to the ground. This spares structures from being hit by lightning and thus being damaged. So your lightning rod typically has a metal cable that extends down from the rod and then is bury. It has like a conductive stake as well that's buried in the ground, and that channels the current from the lightning down into the ground. Or really it just gives the current a different direction to travel, honestly, but if you look at lightning, current goes from the ground up to the sky. It doesn't matter. The point being that he was able to figure out a way of sparing houses by using lightning rods. So he also established something about electricity that folks when they're first learning about it. Franklin established electricity is having two natures. He called it the resinous electricity, which he viewed as a dip in the electric fluid from the normal amount and thus negative. So this is where the charge is flowing too. This would be akin to that idea of a vacuum. You have a lack of something a hole, and thus something else goes to fill the hole. Then there was what he called vitreous electricity, which was an excess of electric fluid and thus a positive amount. So Franklin said, the movement of electricity goes from positive to negative. You have an over abundance of this electric fluid and it moves to where you have a deficiency of electric fluid. So this is somewhat confusing if you're looking at the scientific description of what's happening with your basic electric circuit where you're having negatively charged part of that is electrons go from an area of high concentration to an area of low concentration. It's going from negative to positive, not positives to negative. But it's because you're looking at two different definitions of what is positive and what is negative. That's where the real confusion lies. So when we talk about electronics and we talk about electron flow and we're looking at it purely from a charge perspective, we're looking at negative particles moving toward a positive side. But let's make it even more confusing than that. There are really two major ways to illustrate charge flow in circuits. One of them is called conventional flow notation, which is the way electrical engineers tend to describe electrical flow, and this follows Franklin's approach. It goes from positive to negative, so electricity flows from the positive terminal to the negative terminal. Because we're talking about the surplus of electrons to the deficiency of electrons. We're not talking about the electric charge, we're talking about the number. There's more electrons over here than they're over there, So that's why this is going to be the positive terminal with more electrons and the negative terminal has fewer electrons because we're talking about surplus and deficiency. But there's also electron flow notation now that one looks at the actual charges, not the numbers. So in that case, the negative terminal is where the electrons are and it flows to the positive terminal. Both illustrations can describe the exact same circuit, but they're going to show a difference in what is positive and negative terminals, and so it can get really confusing. Engineers tend to use that conventional flow notation, professional scientists tend to prefer the electron flow notation, and thus we're all left scratching our heads. All that being said, and an enlightened person might argue that Franklin's description is perfectly suitable if we look at other examples of electric charge moving across an area, Because yes, in wires we're talking about those negatively charged electrons, but in other substances you might talk about protons. Or positively charged ions moving due to a difference in charge. And because you have these positively charged ions or even subatomic particles and their movement can also be described as electricity, It's perfectly valid. It's just not what we see with electronic circuits. So there's that. Still a lot of folks bemow the fact that Franklin's decision to name things as he did was kind of based on a whim and it made things more complicated as we learned more later on. But honestly, there was no way for him to know at the time. It's not really his fault, it just kind of turned out that way. Anyway, back to the timeline, Since we won't learn about electrons for a couple one hundred years after Benjamin Franklin's work with lightning, we should just go back to what people were experimenting with and learning about. So a few decads after Franklin's experiments, there was a guy named Charles Augustine de Colombe who made some significant contributions to our understanding of electricity. He published multiple papers on the subjects of electricity and magnetism between seventeen eighty five and seventeen ninety one, and he had done a lot of work leading up to those publications. Among his discoveries was the relationship between the strength of opposite charges and that distance between them. He developed what we now call Coulomb's law. Now, this law states the electrical or magnetic force depends upon the strength and nature of the charges of the two objects and the distance between those two objects. So, if you have two similarly charged objects, like two positives, they repel one another with a non contact force. Two opposite charged objects, a negative and a positive, will attract one another with a non contact force. These forces are vector quantity, which means they have both a magnitude and a direction, and the distance between the two objects affects the amount of force. The closer the objects are to one another, the greater the force is between them. Or, in other words, that the magnitude of the electrostatic force of attraction between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them. That's the technical description of Coulomb's law. There's also a constant that you have to use when you're working with equations. Using Culolm's law, but we don't need to really dive into that, the point being that he realized that distance definitely plays a factor with these other forces that we still didn't fully understand at that point. Then you have Alessandro Volta, from whom we get the word volt He was an Italian physicist who became interested in the study of electricity. Now we normally credit Volta with the invention of the electric battery, those Bagdad batteries set aside. He began by building on the work of another physicist named Johann Carl Vilk, who had invented the electroforts. The electrofus was a simple capacitative generator that could build up an electrostatic charge for use and experiments. So all these scientists really wanted to study electricity, but to do that you had to build up these electrostatic charges so that when you discharged them, you had something to study. So this was a guy who had developed the electro forest as a way of making that easier to do. Volta's buddy Luigi Galvani had observed something really unusual himself. He noted that when he used two different types of metal to make contact with the muscle of a frog, an electric current would pass between the two, and so he thought the source of the electricity was from the frog itself, and he called it animal electricity. Volta disagreed, saying that the frog was just a conductor, not the generator, and so he was call it metallic electricity. And this was a big debate in circles at the time. So in seventeen ninety two, Volta began to experiment on metals, often using his own tongue as the laboratory. He would put two different discs of metal on his tongue and feel the tingling on his tongue and say, yep, there's an electric current passing there. But he could also use other stuff as well, and he was able to observe that in fact, it was the metals that were important, not the creature. This also inspired Volta to look into electricity further, which culminated with the design of the first real battery as far as modern science is concerned. It was in eighteen hundred that Volta invented the voltaic pile, also known as the voltaic column. This battery consisted of alternating layers of zinc and silver, or of alternating layers of copper and pewter with layers of paper or cloth soaked in a salt solution in between the different metal discs. This arrangement could create a steady electric current that didn't need recharging like a Leyden jar did. So this was a great solution for engineers and scientists who wanted to be able to work with electricity but didn't want to have to stop every time they discharged Leyden jar to build up another electrostatic charge. This was a steady source, so it was a huge boon, although we didn't really have any other practical applications for electricity just yet. But six weeks after Volta published his findings, English scientists William Nicholson and Anthony Carlisle experimented with a voltaic pile and electrodes placed in water, and the electric current that passed through the water caused the water to decompose into hydrogen and oxygen, breaking the molecules of water apart. And this is a process that we call electrolysis, specifically with water, but with other things as well, using electrical charges to break those molecular bonds. By eighteen oh two, William Crookshank had designed the first electric battery for mass production, using copper and zinc in a wooden box filled with an electrolyte a brine and sealed to prevent leaking. So a big think of a big wooden battery akin to something like a car battery, would be like this today. So Volta died in eighteen twenty seven, and it was in eighteen eighty one that the scientific community decided to name the unit of electromotive force the vault, after him. So he did not live to see his name used to describe electromotive force, but he certainly was the inspiration for it, and other inventors and scientists would improve upon Volta's design, including chemist John F. Daniel and later a physician from France named Gaston Plante, who designed the first rechargeable lead acid battery. So Plante's design is the basis for modern lead acid batteries today, like the kind you would find in internal combustion engine vehicles. That has its roots back in the early early to mid nineteenth century. It's kind of incredible. Later on you would see other improvements with battery technology. Might as well stick with that for right now. That would include the nickel cadmium battery, which was first designed by Valdemar Jungner from Sweden in eighteen ninety nine, and the nickel iron battery designed by Thomas Edison, or at least Thomas Edison's team of engineers and scientists. There's always a caveat whenever you say Thomas Edison's invention, because he had a whole lot of people working for him who were busy research and developing all sorts of different technologies, and Edison's name gets attached to a lot of it. Edison himself was a brilliant guy, but he largely was brilliant in bringing people to work on these cool ideas, sometimes contributing to him directly. Sometimes he wasn't, but he was providing the space for that kind of work to happen. Anyway. He helped develop the first nickel iron battery in nineteen oh one. But I've talked a lot about batteries, So what I'll do in the next section is talk about other developments in electricity. But before I jump into that, let's take another quick break to thank our sponsor. So one of Volta's contemporaries was Andre Marie Ampere, and we talk about amps and amperage. It comes from ampere, so his name also serves as a type of scientific unit, basically one describing current as opposed to voltage. Ampierre noted in eighteen twenty that a wire carrying an electric current was sometimes attracted to and other times repelled by other such wires. So he was starting to notice this magnetic attraction along current carrying wires, and in eighteen thirty one another fellow, Michael Faraday, explored this idea further, and he discovered that if he revolved a copper disc inside a strong magnetic field, it would generate an electric current inside the copper disc. Faraday and a guy named Humphrey Davey would later build an early electric generator using this discovery. The generator consisted of a coil of copper that would be moved past a magnet, and this is the very very rough basic idea for electric generators today. Moving a conductor through a magnetic field induces electricity to flow through the conductor. That's the simplified version. Now. More specifically, the greatest current flows through a conductor when the conductor is moving through the most lines of magnetic flux at the fastest rate. So magnetic flux is a magnetic field passing through a surface. You've probably seen illustrations of magnetic fields. Imagine a bar magnet. It's just a simple rectangle. You have a north pole of the bar magnet and a south pole of the bar magnet. You would draw lines extending outward from the north pole. These lines would start to loop back down toward the south pole in ever increasing but less strong magnetic lines that go further out until you get a couple that don't even loop back down to the south pole. They just go outward. So lines extend out from the north pole and go in to the south pole, and you designate this by drawing little arrows on the lines to show the direction of this, the vector quality of this. At the south pole, you've got all those incoming lines, including a couple from apparently external sources. When you look at the illustrations of magnetic fields, so if you move a conductor through these magnetic fields, it sort of breaks the lines. It moves through those lines of magnetic force, and you do it quickly, current will flow through the conductor. It induces current to flow, and the most current will flow when the conductor moves through the ninety degree perpendicular plane with respect to the magnetic field. So again, if you've got let's imagine that the conductor is a square. We've got a square of copper. It's not solid copper, it's just a copper wire that's been shaped in the form of a square. It's got two prongs at the base of it that go down to where there's a crank, so I can turn the crank and this will rotate the square. Right now, let's say to either side of the square, I put two very powerful magnets. One of them has the north pole facing into the gap, the other one has its south pole facing into the gap. The squares in the center in between these two magnets. When I turn the square so that it is perpendicular to the magnetic field extending out from these magnets, that is the moment when it's going to have the most current flowing through the square as it moves. It has to be moving for this to really work. When you get it parallel with the magnetic fields, you will have the least amount of current. In fact, you have no current at all flowing through it at that moment. If you keep it turning. Then you will be able to generate current fairly consistently. It does actually pulse, it's not steady. If you were to measure it out, you would actually see it pulsing. And not only does it pulse, the direction of current will change, so it's actually alternating current. But we'll talk about that again in a little bit more a little bit later. To really get into alternating current was in eighteen thirty two there was a French inventor named Pixie PIXII Hippolyte Pixie or Hippolyta if you prefer, But he built an electrical generator based off of Faraday's discoveries that was very similar to what I just described. It had these permanent magnets that had a rotating conductor that would actually really had a spinning magnet and a steady conductor. But same principle, right, you've got a spinning magnet and a steady conductor. You could rearrange that as a spinning conductor and a steady magnet, doesn't really matter. He found that the current's direction changed each time the north pole passed over the coil after the south pole had passed over the coil, and this was an early alternating current generator, but there was no real use for alternating current at that time, so AMPI advised Pixie to design a generator with a device known as a commutator. Commutators are meant to change alternating current to direct current. So the difference between alternating current and direct current is alternating current changes the direction of the current. So you'll have electrons flowing through a circuit in one direction and then they will reverse and flow into the other direction with alternating current, and they do this many times every second. Then you have direct current where the direction of flow is always the same. It goes from if you're doing the conventional flow diagram, it goes from the positive terminal to the negative terminal, and it's never going to change. It's always going to follow that. Batteries give off direct current. Power plants that use AC generators give off AC current, and I'll talk more about that in part two. But why do generators create alternating current and how do commutators work? Well, remember that example I just gave. You've got this square rotating conductor copper wire. It's in between the two magnets. Say that you've got your square position between the south pole of one magnet the north pole of the other magnet, And at the moment you're holding the square steady between the two magnets, and you put a piece of blue tape on the side that's facing magnet number one, which has the south pole facing into the gap, and you put a piece of red tape on the side facing magnet two, which is the north pole of the other magnet. And then you rotate the square so that it moves down or back with respect to magnet one, and up or forward with respect to magnet two. So if you're staring at this, you see that blue tape start to move down. Let's say that we've got this horizontally aligned. It appears to move down with respect to the magnets. The red tape moves up with respect to the magnets, and as it does this, it induces current to flow in one direction in the copper wire. But once the square hits that parallel position with the magnetic fields and then continues its turn, the side that was going up is now going down through a magnetic field, and the side that was going down through a magnetic field is now going up through a magnetic field. So the red tape takes this turn starts moving downward. The red blue tape is making its turn and moving upward, and at that moment, when the conductor breaks that parallel plane, the current reverses direction. Turning the conductor quickly will induce more current to flow and increase the number of cycles the current flow reverses per given unit of time. Now, as I said, this is alternating current, but the early experiments for the day, they really need a direct current, not alternating current, which means you have to find a way to make the current flow stable in a single direction, and that's where a commutator comes in. A simple commutator is a split ring where the two sides of the ring are made up of a conductive material, but they're insulated from each other with an insulating material in between them. So imagine a ring that has one tiny sliver cut out of the ring, so it's like two halves of a ring, and then you have an insulator in between the two halves. On either side of this split ring, you have elements that we call brushes. These are just conductive materials that are stationary contacts. They make contact with this rotating split ring. So as the conductor turns, so does the split ring, and while the direction of current changes within the conductor, the nature of the split ring makes the flow of current and the overall circuit unidirectional. Now I realize this is really difficult to visualize without help, so I actually recommend that you go look up videos about DC generators to get a better idea of what I'm talking about, because a DC generator at its most basic level is really an AC generator with a commutator attached to it. The important thing to note is that the basic generator makes altrain current and the commutator makes it into direct current. Now, at this stage, electricity was still something scientists and engineers would experiment with. They still didn't have any real practical uses for electricity right now, not on a massive scale at any rate. But over the course of the nineteenth century it became clear that electricity had the potential. It's another electricity pun for you to change the world. I hope you enjoyed that classic episode of tech Stuff from June twenty eighth, twenty seventeen. Next week we will obviously have Part two, the conclusion of this two part series on the history of electricity. Until then, I hope you are all well, and I'll talk to you again really soon. Tech Stuff is an iHeartRadio production. For more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. No