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