Speaker 1: Welcome to tech Stuff, a production from iHeartRadio. Hey there,
Speaker 1: and welcome to tech Stuff. I'm your host, job and Strickland,
Speaker 1: I'm an executive producer with iHeart Podcasts and how the
Speaker 1: tech are you? So it is Friday, It's time for
Speaker 1: a classic episode, which means we dive into the tech
Speaker 1: Stuff archive and pull out an episode from our past
Speaker 1: to listen to. This one, originally published on June twenty eighth,
Speaker 1: twenty seventeen, is called The History of Electricity Heart one,
Speaker 1: which kind of spoils what we're going to be talking
Speaker 1: about in next week's classic episode, but you know, there's
Speaker 1: no gain around it. I hope you enjoy this classic episode.
Speaker 1: So first, let's define what electricity is, or rather, instead
Speaker 1: of letting me define it, let's use Miriam Webster, because
Speaker 1: that's kind of their job. Electricity is a fundamental form
Speaker 1: of energy, observable in positive and negative forms, that occurs
Speaker 1: naturally as in lightning, or is produced as in a generator,
Speaker 1: and that is expressed in terms of the movement and
Speaker 1: interaction of electrons. That's actually kind of a little simplistic.
Speaker 1: It's talking about the move of electrons. It's really more
Speaker 1: about the move of electric charge and not of electrons. Specifically,
Speaker 1: if you had some other carrier that was carrying electric charge,
Speaker 1: it would be more about the movement of that carrier.
Speaker 1: As it turns out, electrons are the naturally occurring negatively
Speaker 1: charged particles sub atomic particles that are concerned, especially with electronics.
Speaker 1: So it's understandable, but I just want to point that
Speaker 1: out that it's really more about electric charge and less
Speaker 1: about the actual sub atomic particles. Don't worry, even though
Speaker 1: we'll be talking a lot about electrons. I promise this
Speaker 1: show won't be too negative. I'm seriously done with pun
Speaker 1: for just a bit now. To further define electricity, it
Speaker 1: helps if we get some basic ideas established. Now, keep
Speaker 1: in mind these aspects of electricity were not understood for centuries.
Speaker 1: So when I go into the history of electricity, remember
Speaker 1: that for the vast majority of our experience working with
Speaker 1: and trying to understand electricity, we did not have any
Speaker 1: knowledge of the underpinning foundational physics. Right we were making
Speaker 1: observations and we were even building things that could take
Speaker 1: advantage of this stuff, but we didn't actually understand what
Speaker 1: it was doing or how it was working, which I
Speaker 1: always find really fascinating this idea that we can harness
Speaker 1: something without fully understanding what it is and how it works.
Speaker 1: But it's good for us, as in myself and you
Speaker 1: guys the audience, to understand some of these basics before
Speaker 1: we get too far into the discussion. Otherwise I have
Speaker 1: to keep interrupting the history lesson for science lessons, and
Speaker 1: then it gets kind of a little complicated. Some of
Speaker 1: that's gonna happen anyway, but I want to get the
Speaker 1: foundation out of the way. So the most important thing
Speaker 1: to remember here is that we're talking electric charge, and
Speaker 1: we want to make sure we can make sense of this.
Speaker 1: It's time to get current on our terms. So I
Speaker 1: guess that really wasn't the last pun I'll be talking about.
Speaker 1: So electric charge comes in two flavors, positive and negative,
Speaker 1: positive charge and negative charge. You're probably very familiar with this.
Speaker 1: On the sub atomic particle level, pot you know, we
Speaker 1: have our protons, those are positively charged. We have our electrons,
Speaker 1: those are negatively charged. Now, opposite charges attract one another
Speaker 1: in circuits. A carrier moves negative charges to a source
Speaker 1: of positive charge. So some sort of sub atomic particle
Speaker 1: needs to carry that negative charge throughout a circuit until
Speaker 1: it can get to the source of a positive charge.
Speaker 1: Because negative quote unquote wants to be with positive. It
Speaker 1: doesn't really want anything, it's just that's the natural tendency,
Speaker 1: right these for these two different charges to attract one another. Now,
Speaker 1: in practical terms, the carrier is an electron. So that's
Speaker 1: why we talk about electricity, it's why we talk about electronics.
Speaker 1: It's the subatomic particle that possesses negative charge. So if
Speaker 1: we do a basic electrostatic experiment where we take a
Speaker 1: block of wax and we rub that block of wax
Speaker 1: with some wool, we will build up an electrostatic charge.
Speaker 1: So what's happening is we are imparting a negative charge
Speaker 1: to the wax and creating a positive charge to the wool. So,
Speaker 1: in practical terms, that means the wax has a surplus
Speaker 1: of electrons and the wool has a deficiency of electrons. Effectively,
Speaker 1: you are rubbing some of the electrons from the wool
Speaker 1: onto the wax. That makes the overall charge of the
Speaker 1: surface of the wax negative. It makes the overall charge
Speaker 1: of the surface of the wall possi And if we
Speaker 1: create a pathway that electrons can follow from the wax
Speaker 1: to the woll. Then electrons will take that pathway pop
Speaker 1: back over to the wool and sort of repair that
Speaker 1: deficiency where that deficiency of electrons will be balanced out,
Speaker 1: where electrons will journey back over and rejoin, and they'll
Speaker 1: probably be a big party, you know, or at least
Speaker 1: a sub atomic one. And that's the basics for electric charge.
Speaker 1: So now we have to build on this foundation. There
Speaker 1: are three other basic concepts that we need to understand,
Speaker 1: and those are voltage, current, and resistance. Now these will
Speaker 1: be important throughout the discussion of electricity, particularly as people
Speaker 1: begin to get a deeper understanding of what was actually
Speaker 1: happening with electricity. Voltage is probably the trickiest one for
Speaker 1: people who aren't inclined toward electronics and electricity. It's all
Speaker 1: about potential energy, specifically the potential energy represented by a
Speaker 1: pair of different electric charges. So voltage is sort of
Speaker 1: like pressure. You can imagine it as a force that
Speaker 1: pushes electrons through a conductor, which is oversimplifying, but it's
Speaker 1: helpful when you imagine it that way. So voltage is
Speaker 1: the pressure in the system. The higher the voltage, the
Speaker 1: greater the pressure, the stronger that push is a low
Speaker 1: voltage has very little push, while high voltage has a
Speaker 1: whole lot of push, and we need voltage to make
Speaker 1: electronics work. Otherwise nothing is going to cause a current
Speaker 1: to flow through a circuit. You can also kind of
Speaker 1: think of it as potential energy in the form of
Speaker 1: as an analogy of kinetic energy. So let's say that
Speaker 1: you have a level surface upon which you've got a
Speaker 1: two little corrals of marbles. They don't really have any
Speaker 1: potential energy with respect to one another, they're on the
Speaker 1: same level. But let's say you raise one of those up.
Speaker 1: You tilt it and you raise it up, so the
Speaker 1: corral is still holding the marbles in. But now the
Speaker 1: marbles have potential energy because they're at a higher level
Speaker 1: than the lower marbles. And then let's say you were
Speaker 1: to connect a little slide between the top corral and
Speaker 1: the bottom corral and allow the marbles to roll down
Speaker 1: the hill. Well, this would be sort of like a
Speaker 1: copper wire connecting an area that has a surplus of
Speaker 1: electrons to an area that has a deficiency of electrons.
Speaker 1: It's allowing for the movement of those electrons. Now, in
Speaker 1: the case of voltage, we're really talking about electric potential.
Speaker 1: Here we're not talking about kinetic energy or potential energy
Speaker 1: that could be converted into kinetic energy. Is really just
Speaker 1: meant as an analogy. So when we talk about voltage,
Speaker 1: we talk about it with respect of two points on
Speaker 1: a circuit. So a voltage difference between two points on
Speaker 1: a single circuit and their potential difference really which we
Speaker 1: may also call a voltage. The potential difference between two
Speaker 1: points is measured in a unit called volts. No big
Speaker 1: surprise there. A volt is the amount of energy needed
Speaker 1: to force an electrical current of one ampier more on
Speaker 1: that in a second, through a resistance of one ome
Speaker 1: more on that in a second two at a particular temperature. Now,
Speaker 1: you can have a voltage between two points without having
Speaker 1: any connection between them, So you can have a voltage
Speaker 1: between two things that do not have an active pathway
Speaker 1: between the two. If the distance between the two points
Speaker 1: is decreased, then that electrostatic field that the voltage difference
Speaker 1: creates will intensify. If you increase the space between those
Speaker 1: two points, the electrostatic field will diminish. So distance plays
Speaker 1: a factor, not just the difference in voltage, so that
Speaker 1: covers voltage, but now let's talk about current. So technically
Speaker 1: the current is a flow of electrical charge, and we
Speaker 1: commonly think of it as the movement of electrons, but
Speaker 1: again that's an oversimplification. You can actually have a flow
Speaker 1: of positive charge and that would still be a current.
Speaker 1: If you add a flow of positive charge, that's technically
Speaker 1: a current. But when we're talking about circuits and electronics,
Speaker 1: we're really talking about electrons, not positively charged electrical charges,
Speaker 1: So we tend to simplify it and say it's the
Speaker 1: flow of electrons. Just keep in mind that is an
Speaker 1: oversimplification because electrons are the charge carriers of negative charge. Now,
Speaker 1: in a way, you could think of it as electrons
Speaker 1: are the messengers and the electric charge they carry is
Speaker 1: the message, and that's what's really important. But in practical terms,
Speaker 1: we can just simplify it to electrons. We measure current
Speaker 1: in ampiers and that gives us a sense of the
Speaker 1: intensity or quantity of a charge. So voltage is the
Speaker 1: force behind moving a charge, and amperage tells you how
Speaker 1: much charge is actually moving. And this can help if
Speaker 1: you start to imagine voltage as being a locomotive engine
Speaker 1: and the amperage as being a series of train cars.
Speaker 1: So a low amperage current you might think of as
Speaker 1: just being two or three train cars being pushed by
Speaker 1: a locomotive engine. But you might think of a high
Speaker 1: amperage as being a series of train cars like fifteen
Speaker 1: or twenty being pushed by that same locomotive engine. In
Speaker 1: both cases, the locomotive engine is putting out the same
Speaker 1: amount of force. It's just that in one case it's
Speaker 1: pushing a relatively small number of train cars and the
Speaker 1: other one that's pushing a larger number. But the amount
Speaker 1: of force that's using for both is the same. So
Speaker 1: that's the difference between current and voltage, or if you
Speaker 1: prefer amperage and volts. Now, current will get a bit
Speaker 1: more confusing when we start talking about the direction of flow,
Speaker 1: and that's thanks to a certain founding father of the
Speaker 1: United States. But I don't want to jump ahead. We'll
Speaker 1: get there. When we get there, I'll save that for
Speaker 1: a little bit later in this episode. Finally, we have
Speaker 1: the concept of resistance, and as the name suggests, this
Speaker 1: is the property of a material to resist the flow
Speaker 1: of electric charge. A material with a very high resistance
Speaker 1: is an insulator. It does not allow electric charge to
Speaker 1: pass through it very easily. You would have to use
Speaker 1: a great deal of energy to move an electric charge
Speaker 1: through that kind of material. A material with very low
Speaker 1: resistance is a conductor. It will allow electric charge to
Speaker 1: flow through relatively easily. Now, even conductors have resistance. You
Speaker 1: have to get to very low temperatures, like super frozen
Speaker 1: temperatures almost close to absolute zero to get to super
Speaker 1: conductivity where you have zero resistance and a conductor becomes
Speaker 1: an ideal or perfect conductor. But at other temperatures there's
Speaker 1: some resistance. You can get around that by making a
Speaker 1: cable thicker. Thin cables have a higher resistance than thicker cables,
Speaker 1: But that's kind of beyond what we're talking about here.
Speaker 1: We measure resistance in Ohms and Ohm. George Ohm, who
Speaker 1: is a physician who kind of figured all this stuff out,
Speaker 1: developed Ohm's law. Now that tells us that voltage is
Speaker 1: equal to current times resistance, or you could say current
Speaker 1: is equal to voltage divided by resistance, or that resistance
Speaker 1: is equal to voltage divided by current. It's this relationship
Speaker 1: between current, resistance and voltage that is inherent in electricity
Speaker 1: and electronics. Now, those basic concepts are the very foundation
Speaker 1: for all electronics. Now, obviously it gets more complicated and
Speaker 1: you can add in all sorts of different elements besides that,
Speaker 1: with like diodes and things of that nature. But I
Speaker 1: just wanted to get that covered as the basis for
Speaker 1: the conversation that follows. And now we're going to dive
Speaker 1: into a history lesson. So humans have known about electricity
Speaker 1: in some form for millennia fales of Melitas, And I
Speaker 1: know I'm mispronouncing that, So to all my Greek historians
Speaker 1: out there, I deeply apologize, but I have little Latin
Speaker 1: and less Greek. Along with my buddy Shakespeare. Anyway, he
Speaker 1: had noted that amber, the material amber, would attract light
Speaker 1: materials to its surface after being rubbed. So if you
Speaker 1: rubbed amber with a cloth and then held it toward feathers,
Speaker 1: for example, you had notice that feathers would have a
Speaker 1: tendency to be attracted to the amber. Now, later on
Speaker 1: we would understand that this is static electricity, this is
Speaker 1: building an electrostatic charge using amber. But this was more
Speaker 1: of an observation back in those times, and this is
Speaker 1: centuries before the Common era, and in fact, the word
Speaker 1: electricity comes from the last an electrom, which in turn
Speaker 1: comes from the Greek electron, which means amber. So when
Speaker 1: we talk about electrons, that means that's the Greek word
Speaker 1: for amber. And it's because of this initial well not
Speaker 1: even initial, but this early observation. I just thought that
Speaker 1: was kind of interesting, and you would eventually learn that
Speaker 1: a future engineer scientist named this whole process electricity in
Speaker 1: honor of this early observation. Now in nineteen thirty six,
Speaker 1: we're jumping ahead just to talk about another discovery about
Speaker 1: ancient civilizations. There was a railroad project that ended up
Speaker 1: excavating some ruins southeast of Baghdad, and they revealed what
Speaker 1: we have commonly referred to as the Bagdad batteries. These
Speaker 1: were vessels that appeared to have been designed specifically to
Speaker 1: generate electricity. At least that's one of the hypotheses about
Speaker 1: these these vessels. Some people disagree, but it's a very
Speaker 1: popular one. Now you probably have heard about this in
Speaker 1: some form of another or another. You may have even
Speaker 1: seen the MythBusters episode where they talked about this. The
Speaker 1: team in MythBusters talked about the possible applications for these
Speaker 1: so called batteries, which could include a thing that you
Speaker 1: would use in religious ceremonies, where you would have these
Speaker 1: metal coded vessels that if you were to touch them,
Speaker 1: you would create a circuit and you would allow electricity
Speaker 1: to flow through you, and that would create a tingling
Speaker 1: or numbing sensation in your hands, thus akin to some
Speaker 1: sort of mystical experience and thus being part of a
Speaker 1: religious experience. Or it could be that it was more
Speaker 1: of a practical approach toward something like electroplating, and I
Speaker 1: thought that was really cool. So let's talk about what
Speaker 1: electroplating is, because otherwise, you know, it doesn't really mean
Speaker 1: any thing to you. As the name implies, electro plating
Speaker 1: involves using electricity to cover or plate one material with
Speaker 1: another material. Typically you are plating one type of metal,
Speaker 1: not necessarily metal, but the early version of electro plating
Speaker 1: was metal, but one type of metal with a more
Speaker 1: precious metal. So the reason you might do this is
Speaker 1: to make really pretty expensive looking stuff without using too
Speaker 1: much of the actual precious material. So you might gold
Speaker 1: plate a copper bowl, for example, because you want the
Speaker 1: gold bowl. Gold is more precious than copper, but you
Speaker 1: don't want to actually have to go out and dig
Speaker 1: as much gold as you would need to build a
Speaker 1: gold bowl. So you want to plate the copper bowl
Speaker 1: with gold. That way, it looks exactly the way you
Speaker 1: want it to, but you didn't have to spend all
Speaker 1: that time and effort getting all that gold. In other words,
Speaker 1: we can thank the laziness and greed of human beings
Speaker 1: for some of the early advances as as far as
Speaker 1: electricity is concerned, So you might want to use electroplating
Speaker 1: to do that. We also use electroplating for other purposes,
Speaker 1: like putting rust resistant coatings onto stuff that otherwise would corrode.
Speaker 1: You can also use it to produce alloys like bronze
Speaker 1: and brass. But let's go back to electroplating. So let's
Speaker 1: say these ancient people were using the so called Baghdad
Speaker 1: batteries in order to electroplate gold onto copper. How would
Speaker 1: you do this, Well, first, you have to make sure
Speaker 1: that the copper is totally clean, because if it has
Speaker 1: any schmutz on it, the gold will not properly adhere
Speaker 1: to the copper and it'll flake off. So you typically
Speaker 1: would clean copper this way by dipping it in a
Speaker 1: solution that either is a really powerful alkaline solution or
Speaker 1: a very powerful acidic solution to truly clean it. Once
Speaker 1: you did that, you would then attach a conductor from
Speaker 1: the battery to the copper that you're playing on electroplating.
Speaker 1: So if it's a bowl, then you would want to
Speaker 1: make sure that the terminal, the proper terminal from the
Speaker 1: Bagdad battery is in contact with that copper bowl. Then
Speaker 1: you would put that whole thing, the copper bowl with
Speaker 1: the terminal into an electrolyte solution, which is in this
Speaker 1: case a gold based electrolyte, so you have gold particles
Speaker 1: within the electrolyte itself. Now, electrolytes, by the way, are
Speaker 1: materials that dissociate into ions when dissolved in a suitable medium,
Speaker 1: and become a conductor of electricity. So ions, of course
Speaker 1: our variations of atoms that have a net charge on them.
Speaker 1: They're not neutral. They have either a net negative or
Speaker 1: a net positive charge. So when you do this, you've
Speaker 1: got your gold ions in this electrolyte solution. You then
Speaker 1: put the electrodes together so that not together, but within
Speaker 1: the solution, and so that a current can pass through
Speaker 1: the electrodes. Allow the current to go through the electrolyte
Speaker 1: into the other terminal or the other electrode, and you've
Speaker 1: got a negative and a positive electrode. So when the
Speaker 1: current passes through the electrolyte, the electrolyte splits up and
Speaker 1: some of the metal atoms contained within the electrolyte are
Speaker 1: deposited on one of the two electrodes that you inserted
Speaker 1: into the electrolyte. So what's really happening is the metal
Speaker 1: atoms are ions. They hold that charge, they're attracted to
Speaker 1: the electrode that has the opposite charge and they attach
Speaker 1: to it. So if you have a negatively charged terminal
Speaker 1: and you have positively charged gold ions, that opposite attract
Speaker 1: rule still takes place, and the gold will plate onto
Speaker 1: the copper electrode or bowl in this case, and then
Speaker 1: you've got your gold plated copper thingam a jig, which
Speaker 1: is kind of cool. Now, there's some who put forth
Speaker 1: the hypothesis that perhaps ancient people's made other uses of
Speaker 1: electricity all the way up to even powering lights in
Speaker 1: ancient Egypt, but most scholars that I have consulted dismissed
Speaker 1: this as unrealistic. I haven't really seen much evidence to
Speaker 1: support this apart from some circumstantial evidence. Some supporters cite
Speaker 1: a hieroglyphic relief that shows what to our modern eyes
Speaker 1: appears to be an enormous light bulb. But the accepted
Speaker 1: interpretation of that hieroglyph seems to be that it's a
Speaker 1: lotus leaf with the figure of a snake on it,
Speaker 1: not a huge ancient light bulb. Still, it seems that
Speaker 1: there was at least some knowledge of the existence of electricity,
Speaker 1: if not what it actually could do or what it was.
Speaker 1: Now that's a trend that would last for centuries. In fact,
Speaker 1: we were making use of electricity well before anyone really
Speaker 1: knew what was going on with it. And again, to me,
Speaker 1: that is one of the phenomenal things about human history
Speaker 1: is when we come across these moments where people have
Speaker 1: figured out something or how to use something without really
Speaker 1: fully understanding why it is, that could be dangerous. Clearly,
Speaker 1: there were plenty of cases of that in the nineteen
Speaker 1: fifties with radiation, where people thought that radiation didn't have
Speaker 1: any particular harmful effects. You might have seen things about
Speaker 1: like using X rays in shoe stores so that people
Speaker 1: could see their feet through the shoes that they were
Speaker 1: trying on, and then only later did we realize that
Speaker 1: X rays are an ionizing form of radiation and that
Speaker 1: we probably should not or definitely should not have been
Speaker 1: doing that same sort of thing with electricity. We were
Speaker 1: putting it to use before we ever really understood what
Speaker 1: was going on there. But of course electricity isn't ionizing radiation,
Speaker 1: so it does have very different effects than radiation does.
Speaker 1: But what follows is a brief history of the developments
Speaker 1: that unfolded as very very smart people figured out what
Speaker 1: the heck electricity is. So in the fifteen hundreds you
Speaker 1: had an English physician and proto scientist named William Gilbert
Speaker 1: who began to experiment with magnets and static electricity. So
Speaker 1: he used loadstone, which is naturally magnetic iron ore, and
Speaker 1: he published his work in sixteen hundred under the title
Speaker 1: d Magnetae or Magnety. It's magneto but with a knee.
Speaker 1: He was able to describe magnetism and static electricity as
Speaker 1: distinct phenomena, though he wasn't really sure what was actually
Speaker 1: causing it. His hypothesis was that there was some sort
Speaker 1: of fluid or humor, as in the various humors of
Speaker 1: the body. There was another prevailing physical theory at the time,
Speaker 1: and that this was the cause of attraction with static electricity,
Speaker 1: and that if you rubbed amber, what you were actually
Speaker 1: doing was removing some of that fluid from the amber,
Speaker 1: which created a hole or like a vacuum around it,
Speaker 1: and this is why light objects would become a tra
Speaker 1: to the amber. He called it effluvium and described it
Speaker 1: as an electric effect. In sixteen sixty, an inventor named
Speaker 1: Auto von Geirica built a machine using a globe made
Speaker 1: of sulfur, and if you rubbed the globe as it turned,
Speaker 1: you could build up a charge, an electrostatic charge, causing
Speaker 1: it to attract small light objects, such as feathers or
Speaker 1: scraps of paper. Gherica also observed that his invention would
Speaker 1: cause a spark if you rubbed the globe for long enough.
Speaker 1: You could then touch something metal like a brass knob,
Speaker 1: and see a spark fly between the electrostatically charged object
Speaker 1: and the grounded piece of metal. Stephen Gray, another English scientist,
Speaker 1: observed in seventeen twenty nine that some stuff doesn't conduct
Speaker 1: electricity at all, so he thought some materials would allow
Speaker 1: the fluid of electricity to flow through, and other materials
Speaker 1: would hamper the flow of this fluid. Electricity would which
Speaker 1: is sort of true when you get to electrical resistance,
Speaker 1: only we're not talking about a fluid really. Later that century,
Speaker 1: Dutch inventor's Pietr von Mussen book and evolved von Kleist
Speaker 1: created what we now call the Leyden jar, and there
Speaker 1: are actually two variations on basic Leyden jars, which store
Speaker 1: electrostatic charges. They're essentially capacitors, So you build up an
Speaker 1: electric static charge in this thing, and then when you
Speaker 1: touch the the charged component, you allow that electrostatic charge
Speaker 1: to discharge to spark, so they release all of that
Speaker 1: charged energy in an instant. Unlike a battery, which releases
Speaker 1: uh well, which which creates the voltage difference and allows
Speaker 1: for electric electric current to flow over time, a capacitor
Speaker 1: releases it in a in a moment. The There are
Speaker 1: two basic versions of the Leaden jar, and the first
Speaker 1: one uses a metal container inside which you have a
Speaker 1: glass vessel nestled inside that metal container, and inside the
Speaker 1: glass vessel you have a second metal container nestled inside that.
Speaker 1: So it's kind of like a sandwich where the bread
Speaker 1: is metal container and the bread and the meat inside
Speaker 1: is glass. I don't recommend eating that sandwich, it would
Speaker 1: not taste good and probably hurt you. But it was
Speaker 1: that layer metal glass metal, and you would then also
Speaker 1: have a rod of metal that would extend up from
Speaker 1: the base of that interior lining. So imagine like a
Speaker 1: column rising up from that internal metal cup inside the
Speaker 1: glass vessel, which in turn is inside a larger metal vessel.
Speaker 1: The second variation has a metal vessel filled with a
Speaker 1: conductive fluid like water that's got a salt dissolved in it.
Speaker 1: One or on its own will conduct electricity as long
Speaker 1: as it has some impurities in it, but you can
Speaker 1: make it conduct electricity more effectively by adding or doping
Speaker 1: the water with some of those impurities, and it would
Speaker 1: have a metal rod sticking out from the water. Now,
Speaker 1: both versions would allow you to do essentially the same thing,
Speaker 1: which is store up that electrostatic charge. And you do
Speaker 1: this by building up an electric static charge in something else.
Speaker 1: So you might take some amber, for example, and rub
Speaker 1: the amber. Then you would bring that into contact with
Speaker 1: that metal bar that's extending upward from the jar. That
Speaker 1: would introduce a charge to one plate in this capacitor,
Speaker 1: and that would create the opposite charge in the opposing plate.
Speaker 1: In this case, that exterior metal casing. You would need
Speaker 1: to ground the outer metal case, which you could just
Speaker 1: do by touching it yourself, or you could run a
Speaker 1: wire from the exterior metal case to the ground or
Speaker 1: to a metal pipe. And when you create a pathway
Speaker 1: between the plates by touching the charge grod, it creates
Speaker 1: a spark as the charge is able to equalize, and
Speaker 1: that could be a significant shock, depending on how much
Speaker 1: you've built up inside this Leyden jar to the point
Speaker 1: where it could really hurt or possibly do serious damage.
Speaker 1: Both Kleist and Muschlenbrook had shocking experiences with their respective
Speaker 1: Leyden jars, and neither was really sure exactly what was happening.
Speaker 1: Now we've got a lot more to talk about with
Speaker 1: the early discoveries surrounding electricity. But before we get a
Speaker 1: charge out of all that, let's take a quick break
Speaker 1: to thank our sponsors. All right, We're up to seventeen
Speaker 1: fifty two, and that's when we revisit the great founding
Speaker 1: father I had mentioned earlier, Benjamin Franklin. That's when we
Speaker 1: got the legendary experiments that Franklin conducted. He was friends
Speaker 1: with a scientist named Peter Collinson over in Europe, and
Speaker 1: Collinson had sent Franklin an electricity tube. Franklin, like his predecessors,
Speaker 1: thought electricity was a type of fluid, and he hypothesized
Speaker 1: that lightning itself was an electric spark, very much like
Speaker 1: the kind a leaden jar could produce if you built
Speaker 1: up enough of an electrostatic charge, and thus charged forces
Speaker 1: would cause a lightning strike. And he further hypothesized that
Speaker 1: you could use a metal rod to draw lightning to
Speaker 1: a specific location, which could end up saving structures from
Speaker 1: being struck by lightning. So if you had a house
Speaker 1: and it got hit by lightning back in those days,
Speaker 1: your house would very much be damaged, possibly burned down
Speaker 1: as a result. So he thought, well, maybe you could
Speaker 1: draw lightning away using long metal rods. But the problem
Speaker 1: was he couldn't build a metal rod tall enough to
Speaker 1: dwarf the structures. He thought that he was going to
Speaker 1: have to build something that could almost reach the skies themselves,
Speaker 1: which made it too big of a challenge, so he
Speaker 1: came up with this idea of using a kite instead. Meanwhile,
Speaker 1: over in France, Thomas Francois d'alabard decided to put Franklin's
Speaker 1: ideas to the test. He actually constructed a large metal
Speaker 1: pole to try and conduct electricity and declared that Franklin
Speaker 1: was absolutely right that, in fact, that metal rod does
Speaker 1: draw lightning. But this news didn't travel back to America
Speaker 1: that fast. I mean, it took a really long time
Speaker 1: for information to go from one place to another, so
Speaker 1: Franklin was unaware that his hypothesis had proven correct. So
Speaker 1: that same year, Franklin reportedly conducted his experiment using a
Speaker 1: silk kite with a key tied to the silk kite
Speaker 1: down to the string, and as legend goes, he flew
Speaker 1: the kite up during a thunderstorm until the key drew
Speaker 1: lightning to it, and then used that key to charge
Speaker 1: a Leyden jar. So the electric charge in the key
Speaker 1: was then transferred to a leaden jar, which again holds
Speaker 1: electrostatic charge. Now, I say reportedly because Franklin's writings never
Speaker 1: outright said that that was what happened. He never specifically
Speaker 1: said that he himself had performed the experiment. Now, he
Speaker 1: did say that he did a simplified version of this
Speaker 1: plan and that it happened in Philadelphia, but it's unclear
Speaker 1: who was actually flying the kite at the time. And
Speaker 1: according to modern scientists, if Franklin had conducted the experiment
Speaker 1: as it has generally been reported, Franklin would have been toasted.
Speaker 1: He would have been fried scientifically speaking, So the general
Speaker 1: theory about this not scientific theory, but you general idea
Speaker 1: of what actually happened was that Franklin, if he conducted
Speaker 1: the experiment at all, was able to pick up an
Speaker 1: electrostatic charge by flying the kite near a storm, but
Speaker 1: that the kite was never directly struck by lightning. It
Speaker 1: just rather picked up a charge by being lightning adjacent.
Speaker 1: I guess, as you could say, all quibbling aside. By
Speaker 1: this time, it became established that lightning was in fact
Speaker 1: a really big spark. Therefore part of this concept of electricity.
Speaker 1: Franklin made practical use out of this knowledge by inventing
Speaker 1: the lightning rod. Now, the purpose of a lightning rod
Speaker 1: is to attract a bolt of lightning to the rod
Speaker 1: and then channel the electricity down to the ground. This
Speaker 1: spares structures from being hit by lightning and thus being damaged.
Speaker 1: So your lightning rod typically has a metal cable that
Speaker 1: extends down from the rod and then is bury. It
Speaker 1: has like a conductive stake as well that's buried in
Speaker 1: the ground, and that channels the current from the lightning
Speaker 1: down into the ground. Or really it just gives the
Speaker 1: current a different direction to travel, honestly, but if you
Speaker 1: look at lightning, current goes from the ground up to
Speaker 1: the sky. It doesn't matter. The point being that he
Speaker 1: was able to figure out a way of sparing houses
Speaker 1: by using lightning rods. So he also established something about
Speaker 1: electricity that folks when they're first learning about it. Franklin
Speaker 1: established electricity is having two natures. He called it the
Speaker 1: resinous electricity, which he viewed as a dip in the
Speaker 1: electric fluid from the normal amount and thus negative. So
Speaker 1: this is where the charge is flowing too. This would
Speaker 1: be akin to that idea of a vacuum. You have
Speaker 1: a lack of something a hole, and thus something else
Speaker 1: goes to fill the hole. Then there was what he
Speaker 1: called vitreous electricity, which was an excess of electric fluid
Speaker 1: and thus a positive amount. So Franklin said, the movement
Speaker 1: of electricity goes from positive to negative. You have an
Speaker 1: over abundance of this electric fluid and it moves to
Speaker 1: where you have a deficiency of electric fluid. So this
Speaker 1: is somewhat confusing if you're looking at the scientific description
Speaker 1: of what's happening with your basic electric circuit where you're
Speaker 1: having negatively charged part of that is electrons go from
Speaker 1: an area of high concentration to an area of low concentration.
Speaker 1: It's going from negative to positive, not positives to negative.
Speaker 1: But it's because you're looking at two different definitions of
Speaker 1: what is positive and what is negative. That's where the
Speaker 1: real confusion lies. So when we talk about electronics and
Speaker 1: we talk about electron flow and we're looking at it
Speaker 1: purely from a charge perspective, we're looking at negative particles
Speaker 1: moving toward a positive side. But let's make it even
Speaker 1: more confusing than that. There are really two major ways
Speaker 1: to illustrate charge flow in circuits. One of them is
Speaker 1: called conventional flow notation, which is the way electrical engineers
Speaker 1: tend to describe electrical flow, and this follows Franklin's approach.
Speaker 1: It goes from positive to negative, so electricity flows from
Speaker 1: the positive terminal to the negative terminal. Because we're talking
Speaker 1: about the surplus of electrons to the deficiency of electrons.
Speaker 1: We're not talking about the electric charge, we're talking about
Speaker 1: the number. There's more electrons over here than they're over there,
Speaker 1: So that's why this is going to be the positive
Speaker 1: terminal with more electrons and the negative terminal has fewer
Speaker 1: electrons because we're talking about surplus and deficiency. But there's
Speaker 1: also electron flow notation now that one looks at the
Speaker 1: actual charges, not the numbers. So in that case, the
Speaker 1: negative terminal is where the electrons are and it flows
Speaker 1: to the positive terminal. Both illustrations can describe the exact
Speaker 1: same circuit, but they're going to show a difference in
Speaker 1: what is positive and negative terminals, and so it can
Speaker 1: get really confusing. Engineers tend to use that conventional flow notation,
Speaker 1: professional scientists tend to prefer the electron flow notation, and
Speaker 1: thus we're all left scratching our heads. All that being said,
Speaker 1: and an enlightened person might argue that Franklin's description is
Speaker 1: perfectly suitable if we look at other examples of electric
Speaker 1: charge moving across an area, Because yes, in wires we're
Speaker 1: talking about those negatively charged electrons, but in other substances
Speaker 1: you might talk about protons. Or positively charged ions moving
Speaker 1: due to a difference in charge. And because you have
Speaker 1: these positively charged ions or even subatomic particles and their
Speaker 1: movement can also be described as electricity, It's perfectly valid.
Speaker 1: It's just not what we see with electronic circuits. So
Speaker 1: there's that. Still a lot of folks bemow the fact
Speaker 1: that Franklin's decision to name things as he did was
Speaker 1: kind of based on a whim and it made things
Speaker 1: more complicated as we learned more later on. But honestly,
Speaker 1: there was no way for him to know at the time.
Speaker 1: It's not really his fault, it just kind of turned
Speaker 1: out that way. Anyway, back to the timeline, Since we
Speaker 1: won't learn about electrons for a couple one hundred years
Speaker 1: after Benjamin Franklin's work with lightning, we should just go
Speaker 1: back to what people were experimenting with and learning about.
Speaker 1: So a few decads after Franklin's experiments, there was a
Speaker 1: guy named Charles Augustine de Colombe who made some significant
Speaker 1: contributions to our understanding of electricity. He published multiple papers
Speaker 1: on the subjects of electricity and magnetism between seventeen eighty
Speaker 1: five and seventeen ninety one, and he had done a
Speaker 1: lot of work leading up to those publications. Among his
Speaker 1: discoveries was the relationship between the strength of opposite charges
Speaker 1: and that distance between them. He developed what we now
Speaker 1: call Coulomb's law. Now, this law states the electrical or
Speaker 1: magnetic force depends upon the strength and nature of the
Speaker 1: charges of the two objects and the distance between those
Speaker 1: two objects. So, if you have two similarly charged objects,
Speaker 1: like two positives, they repel one another with a non
Speaker 1: contact force. Two opposite charged objects, a negative and a positive,
Speaker 1: will attract one another with a non contact force. These
Speaker 1: forces are vector quantity, which means they have both a
Speaker 1: magnitude and a direction, and the distance between the two
Speaker 1: objects affects the amount of force. The closer the objects
Speaker 1: are to one another, the greater the force is between them. Or,
Speaker 1: in other words, that the magnitude of the electrostatic force
Speaker 1: of attraction between two point charges is directly proportional to
Speaker 1: the product of the magnitudes of charges and inversely proportional
Speaker 1: to the square of the distance between them. That's the
Speaker 1: technical description of Coulomb's law. There's also a constant that
Speaker 1: you have to use when you're working with equations. Using
Speaker 1: Culolm's law, but we don't need to really dive into that,
Speaker 1: the point being that he realized that distance definitely plays
Speaker 1: a factor with these other forces that we still didn't
Speaker 1: fully understand at that point. Then you have Alessandro Volta,
Speaker 1: from whom we get the word volt He was an
Speaker 1: Italian physicist who became interested in the study of electricity.
Speaker 1: Now we normally credit Volta with the invention of the
Speaker 1: electric battery, those Bagdad batteries set aside. He began by
Speaker 1: building on the work of another physicist named Johann Carl Vilk,
Speaker 1: who had invented the electroforts. The electrofus was a simple
Speaker 1: capacitative generator that could build up an electrostatic charge for
Speaker 1: use and experiments. So all these scientists really wanted to
Speaker 1: study electricity, but to do that you had to build
Speaker 1: up these electrostatic charges so that when you discharged them,
Speaker 1: you had something to study. So this was a guy
Speaker 1: who had developed the electro forest as a way of
Speaker 1: making that easier to do. Volta's buddy Luigi Galvani had
Speaker 1: observed something really unusual himself. He noted that when he
Speaker 1: used two different types of metal to make contact with
Speaker 1: the muscle of a frog, an electric current would pass
Speaker 1: between the two, and so he thought the source of
Speaker 1: the electricity was from the frog itself, and he called
Speaker 1: it animal electricity. Volta disagreed, saying that the frog was
Speaker 1: just a conductor, not the generator, and so he was
Speaker 1: call it metallic electricity. And this was a big debate
Speaker 1: in circles at the time. So in seventeen ninety two,
Speaker 1: Volta began to experiment on metals, often using his own
Speaker 1: tongue as the laboratory. He would put two different discs
Speaker 1: of metal on his tongue and feel the tingling on
Speaker 1: his tongue and say, yep, there's an electric current passing there.
Speaker 1: But he could also use other stuff as well, and
Speaker 1: he was able to observe that in fact, it was
Speaker 1: the metals that were important, not the creature. This also
Speaker 1: inspired Volta to look into electricity further, which culminated with
Speaker 1: the design of the first real battery as far as
Speaker 1: modern science is concerned. It was in eighteen hundred that
Speaker 1: Volta invented the voltaic pile, also known as the voltaic column.
Speaker 1: This battery consisted of alternating layers of zinc and silver,
Speaker 1: or of alternating layers of copper and pewter with layers
Speaker 1: of paper or cloth soaked in a salt solution in
Speaker 1: between the different metal discs. This arrangement could create a
Speaker 1: steady electric current that didn't need recharging like a Leyden
Speaker 1: jar did. So this was a great solution for engineers
Speaker 1: and scientists who wanted to be able to work with
Speaker 1: electricity but didn't want to have to stop every time
Speaker 1: they discharged Leyden jar to build up another electrostatic charge.
Speaker 1: This was a steady source, so it was a huge boon,
Speaker 1: although we didn't really have any other practical applications for
Speaker 1: electricity just yet. But six weeks after Volta published his findings,
Speaker 1: English scientists William Nicholson and Anthony Carlisle experimented with a
Speaker 1: voltaic pile and electrodes placed in water, and the electric
Speaker 1: current that passed through the water caused the water to
Speaker 1: decompose into hydrogen and oxygen, breaking the molecules of water apart.
Speaker 1: And this is a process that we call electrolysis, specifically
Speaker 1: with water, but with other things as well, using electrical
Speaker 1: charges to break those molecular bonds. By eighteen oh two,
Speaker 1: William Crookshank had designed the first electric battery for mass production,
Speaker 1: using copper and zinc in a wooden box filled with
Speaker 1: an electrolyte a brine and sealed to prevent leaking. So
Speaker 1: a big think of a big wooden battery akin to
Speaker 1: something like a car battery, would be like this today.
Speaker 1: So Volta died in eighteen twenty seven, and it was
Speaker 1: in eighteen eighty one that the scientific community decided to
Speaker 1: name the unit of electromotive force the vault, after him.
Speaker 1: So he did not live to see his name used
Speaker 1: to describe electromotive force, but he certainly was the inspiration
Speaker 1: for it, and other inventors and scientists would improve upon
Speaker 1: Volta's design, including chemist John F. Daniel and later a
Speaker 1: physician from France named Gaston Plante, who designed the first
Speaker 1: rechargeable lead acid battery. So Plante's design is the basis
Speaker 1: for modern lead acid batteries today, like the kind you
Speaker 1: would find in internal combustion engine vehicles. That has its
Speaker 1: roots back in the early early to mid nineteenth century.
Speaker 1: It's kind of incredible. Later on you would see other
Speaker 1: improvements with battery technology. Might as well stick with that
Speaker 1: for right now. That would include the nickel cadmium battery,
Speaker 1: which was first designed by Valdemar Jungner from Sweden in
Speaker 1: eighteen ninety nine, and the nickel iron battery designed by
Speaker 1: Thomas Edison, or at least Thomas Edison's team of engineers
Speaker 1: and scientists. There's always a caveat whenever you say Thomas
Speaker 1: Edison's invention, because he had a whole lot of people
Speaker 1: working for him who were busy research and developing all
Speaker 1: sorts of different technologies, and Edison's name gets attached to
Speaker 1: a lot of it. Edison himself was a brilliant guy,
Speaker 1: but he largely was brilliant in bringing people to work
Speaker 1: on these cool ideas, sometimes contributing to him directly. Sometimes
Speaker 1: he wasn't, but he was providing the space for that
Speaker 1: kind of work to happen. Anyway. He helped develop the
Speaker 1: first nickel iron battery in nineteen oh one. But I've
Speaker 1: talked a lot about batteries, So what I'll do in
Speaker 1: the next section is talk about other developments in electricity.
Speaker 1: But before I jump into that, let's take another quick
Speaker 1: break to thank our sponsor. So one of Volta's contemporaries
Speaker 1: was Andre Marie Ampere, and we talk about amps and amperage.
Speaker 1: It comes from ampere, so his name also serves as
Speaker 1: a type of scientific unit, basically one describing current as
Speaker 1: opposed to voltage. Ampierre noted in eighteen twenty that a
Speaker 1: wire carrying an electric current was sometimes attracted to and
Speaker 1: other times repelled by other such wires. So he was
Speaker 1: starting to notice this magnetic attraction along current carrying wires,
Speaker 1: and in eighteen thirty one another fellow, Michael Faraday, explored
Speaker 1: this idea further, and he discovered that if he revolved
Speaker 1: a copper disc inside a strong magnetic field, it would
Speaker 1: generate an electric current inside the copper disc. Faraday and
Speaker 1: a guy named Humphrey Davey would later build an early
Speaker 1: electric generator using this discovery. The generator consisted of a
Speaker 1: coil of copper that would be moved past a magnet,
Speaker 1: and this is the very very rough basic idea for
Speaker 1: electric generators today. Moving a conductor through a magnetic field
Speaker 1: induces electricity to flow through the conductor. That's the simplified version. Now.
Speaker 1: More specifically, the greatest current flows through a conductor when
Speaker 1: the conductor is moving through the most lines of magnetic
Speaker 1: flux at the fastest rate. So magnetic flux is a
Speaker 1: magnetic field passing through a surface. You've probably seen illustrations
Speaker 1: of magnetic fields. Imagine a bar magnet. It's just a
Speaker 1: simple rectangle. You have a north pole of the bar
Speaker 1: magnet and a south pole of the bar magnet. You
Speaker 1: would draw lines extending outward from the north pole. These
Speaker 1: lines would start to loop back down toward the south
Speaker 1: pole in ever increasing but less strong magnetic lines that
Speaker 1: go further out until you get a couple that don't
Speaker 1: even loop back down to the south pole. They just
Speaker 1: go outward. So lines extend out from the north pole
Speaker 1: and go in to the south pole, and you designate
Speaker 1: this by drawing little arrows on the lines to show
Speaker 1: the direction of this, the vector quality of this. At
Speaker 1: the south pole, you've got all those incoming lines, including
Speaker 1: a couple from apparently external sources. When you look at
Speaker 1: the illustrations of magnetic fields, so if you move a
Speaker 1: conductor through these magnetic fields, it sort of breaks the lines.
Speaker 1: It moves through those lines of magnetic force, and you
Speaker 1: do it quickly, current will flow through the conductor. It
Speaker 1: induces current to flow, and the most current will flow
Speaker 1: when the conductor moves through the ninety degree perpendicular plane
Speaker 1: with respect to the magnetic field. So again, if you've
Speaker 1: got let's imagine that the conductor is a square. We've
Speaker 1: got a square of copper. It's not solid copper, it's
Speaker 1: just a copper wire that's been shaped in the form
Speaker 1: of a square. It's got two prongs at the base
Speaker 1: of it that go down to where there's a crank,
Speaker 1: so I can turn the crank and this will rotate
Speaker 1: the square. Right now, let's say to either side of
Speaker 1: the square, I put two very powerful magnets. One of
Speaker 1: them has the north pole facing into the gap, the
Speaker 1: other one has its south pole facing into the gap.
Speaker 1: The squares in the center in between these two magnets.
Speaker 1: When I turn the square so that it is perpendicular
Speaker 1: to the magnetic field extending out from these magnets, that
Speaker 1: is the moment when it's going to have the most
Speaker 1: current flowing through the square as it moves. It has
Speaker 1: to be moving for this to really work. When you
Speaker 1: get it parallel with the magnetic fields, you will have
Speaker 1: the least amount of current. In fact, you have no
Speaker 1: current at all flowing through it at that moment. If
Speaker 1: you keep it turning. Then you will be able to
Speaker 1: generate current fairly consistently. It does actually pulse, it's not steady.
Speaker 1: If you were to measure it out, you would actually
Speaker 1: see it pulsing. And not only does it pulse, the
Speaker 1: direction of current will change, so it's actually alternating current.
Speaker 1: But we'll talk about that again in a little bit
Speaker 1: more a little bit later. To really get into alternating
Speaker 1: current was in eighteen thirty two there was a French
Speaker 1: inventor named Pixie PIXII Hippolyte Pixie or Hippolyta if you prefer,
Speaker 1: But he built an electrical generator based off of Faraday's
Speaker 1: discoveries that was very similar to what I just described.
Speaker 1: It had these permanent magnets that had a rotating conductor
Speaker 1: that would actually really had a spinning magnet and a
Speaker 1: steady conductor. But same principle, right, you've got a spinning
Speaker 1: magnet and a steady conductor. You could rearrange that as
Speaker 1: a spinning conductor and a steady magnet, doesn't really matter.
Speaker 1: He found that the current's direction changed each time the
Speaker 1: north pole passed over the coil after the south pole
Speaker 1: had passed over the coil, and this was an early
Speaker 1: alternating current generator, but there was no real use for
Speaker 1: alternating current at that time, so AMPI advised Pixie to
Speaker 1: design a generator with a device known as a commutator.
Speaker 1: Commutators are meant to change alternating current to direct current.
Speaker 1: So the difference between alternating current and direct current is
Speaker 1: alternating current changes the direction of the current. So you'll
Speaker 1: have electrons flowing through a circuit in one direction and
Speaker 1: then they will reverse and flow into the other direction
Speaker 1: with alternating current, and they do this many times every second.
Speaker 1: Then you have direct current where the direction of flow
Speaker 1: is always the same. It goes from if you're doing
Speaker 1: the conventional flow diagram, it goes from the positive terminal
Speaker 1: to the negative terminal, and it's never going to change.
Speaker 1: It's always going to follow that. Batteries give off direct current.
Speaker 1: Power plants that use AC generators give off AC current,
Speaker 1: and I'll talk more about that in part two. But
Speaker 1: why do generators create alternating current and how do commutators work? Well,
Speaker 1: remember that example I just gave. You've got this square
Speaker 1: rotating conductor copper wire. It's in between the two magnets.
Speaker 1: Say that you've got your square position between the south
Speaker 1: pole of one magnet the north pole of the other magnet,
Speaker 1: And at the moment you're holding the square steady between
Speaker 1: the two magnets, and you put a piece of blue
Speaker 1: tape on the side that's facing magnet number one, which
Speaker 1: has the south pole facing into the gap, and you
Speaker 1: put a piece of red tape on the side facing
Speaker 1: magnet two, which is the north pole of the other magnet.
Speaker 1: And then you rotate the square so that it moves
Speaker 1: down or back with respect to magnet one, and up
Speaker 1: or forward with respect to magnet two. So if you're
Speaker 1: staring at this, you see that blue tape start to
Speaker 1: move down. Let's say that we've got this horizontally aligned.
Speaker 1: It appears to move down with respect to the magnets.
Speaker 1: The red tape moves up with respect to the magnets,
Speaker 1: and as it does this, it induces current to flow
Speaker 1: in one direction in the copper wire. But once the
Speaker 1: square hits that parallel position with the magnetic fields and
Speaker 1: then continues its turn, the side that was going up
Speaker 1: is now going down through a magnetic field, and the
Speaker 1: side that was going down through a magnetic field is
Speaker 1: now going up through a magnetic field. So the red
Speaker 1: tape takes this turn starts moving downward. The red blue
Speaker 1: tape is making its turn and moving upward, and at
Speaker 1: that moment, when the conductor breaks that parallel plane, the
Speaker 1: current reverses direction. Turning the conductor quickly will induce more
Speaker 1: current to flow and increase the number of cycles the
Speaker 1: current flow reverses per given unit of time. Now, as
Speaker 1: I said, this is alternating current, but the early experiments
Speaker 1: for the day, they really need a direct current, not
Speaker 1: alternating current, which means you have to find a way
Speaker 1: to make the current flow stable in a single direction,
Speaker 1: and that's where a commutator comes in. A simple commutator
Speaker 1: is a split ring where the two sides of the
Speaker 1: ring are made up of a conductive material, but they're
Speaker 1: insulated from each other with an insulating material in between them.
Speaker 1: So imagine a ring that has one tiny sliver cut
Speaker 1: out of the ring, so it's like two halves of
Speaker 1: a ring, and then you have an insulator in between
Speaker 1: the two halves. On either side of this split ring,
Speaker 1: you have elements that we call brushes. These are just
Speaker 1: conductive materials that are stationary contacts. They make contact with
Speaker 1: this rotating split ring. So as the conductor turns, so
Speaker 1: does the split ring, and while the direction of current
Speaker 1: changes within the conductor, the nature of the split ring
Speaker 1: makes the flow of current and the overall circuit unidirectional.
Speaker 1: Now I realize this is really difficult to visualize without help,
Speaker 1: so I actually recommend that you go look up videos
Speaker 1: about DC generators to get a better idea of what
Speaker 1: I'm talking about, because a DC generator at its most
Speaker 1: basic level is really an AC generator with a commutator
Speaker 1: attached to it. The important thing to note is that
Speaker 1: the basic generator makes altrain current and the commutator makes
Speaker 1: it into direct current. Now, at this stage, electricity was
Speaker 1: still something scientists and engineers would experiment with. They still
Speaker 1: didn't have any real practical uses for electricity right now,
Speaker 1: not on a massive scale at any rate. But over
Speaker 1: the course of the nineteenth century it became clear that
Speaker 1: electricity had the potential. It's another electricity pun for you
Speaker 1: to change the world. I hope you enjoyed that classic
Speaker 1: episode of tech Stuff from June twenty eighth, twenty seventeen.
Speaker 1: Next week we will obviously have Part two, the conclusion
Speaker 1: of this two part series on the history of electricity.
Speaker 1: Until then, I hope you are all well, and I'll
Speaker 1: talk to you again really soon. Tech Stuff is an
Speaker 1: iHeartRadio production. For more podcasts from iHeartRadio, visit the iHeartRadio app,
Speaker 1: Apple Podcasts, or wherever you listen to your favorite shows.
Speaker 1: No