1 00:00:04,200 --> 00:00:12,840 Speaker 1: Get technology with tech Stuff from how stuff works dot com. 2 00:00:12,880 --> 00:00:16,160 Speaker 1: Hey there, and welcome to tech Stuff. I'm your host, 3 00:00:16,320 --> 00:00:19,960 Speaker 1: Jonathan Strickland. I'm a senior writer for how stuff works 4 00:00:20,040 --> 00:00:23,560 Speaker 1: dot com, and today we're gonna take a look at 5 00:00:23,600 --> 00:00:27,680 Speaker 1: the history of electricity, from the earliest experiments all the 6 00:00:27,680 --> 00:00:30,760 Speaker 1: way up to the formation of today's power grid and 7 00:00:30,800 --> 00:00:32,920 Speaker 1: how it all works. Well, at least in this part, 8 00:00:32,960 --> 00:00:36,199 Speaker 1: we're gonna explore the first section of that history. But 9 00:00:36,440 --> 00:00:40,080 Speaker 1: as it turns out, the history of our experimentation and 10 00:00:40,640 --> 00:00:45,000 Speaker 1: knowledge of electricity is exhaustive and I would really need 11 00:00:45,040 --> 00:00:47,200 Speaker 1: to do more than one episode. So this is part 12 00:00:47,320 --> 00:00:49,840 Speaker 1: one of what is likely to be a two part 13 00:00:49,840 --> 00:00:54,080 Speaker 1: episode about the history of electricity. I'll try to limit 14 00:00:54,520 --> 00:00:57,640 Speaker 1: the number of electricity based puns I will drop in 15 00:00:57,680 --> 00:00:59,760 Speaker 1: this episode, but don't be shocked if you hear a 16 00:00:59,800 --> 00:01:04,679 Speaker 1: few of them. So first, let's define what electricity is, 17 00:01:05,400 --> 00:01:08,039 Speaker 1: or rather, instead of letting me define it, let's use 18 00:01:08,160 --> 00:01:12,080 Speaker 1: Miriam Webster, because that's kind of their job. Electricity is 19 00:01:12,160 --> 00:01:15,959 Speaker 1: a fundamental form of energy, observable in positive and negative forms, 20 00:01:16,000 --> 00:01:19,680 Speaker 1: that occurs naturally as in lightening, or is produced as 21 00:01:19,720 --> 00:01:22,560 Speaker 1: in a generator, and that is expressed in terms of 22 00:01:22,600 --> 00:01:26,600 Speaker 1: the movement and interaction of electrons. That's actually kind of 23 00:01:27,160 --> 00:01:29,880 Speaker 1: a little simplistic. It's talking about the move of electrons. 24 00:01:29,920 --> 00:01:33,679 Speaker 1: It's really more about the move of electric charge and 25 00:01:33,760 --> 00:01:38,640 Speaker 1: not of electrons. Specifically, if you had some other carrier 26 00:01:39,200 --> 00:01:41,960 Speaker 1: that was carrying electric charge, it would be more about 27 00:01:41,959 --> 00:01:45,559 Speaker 1: the movement of that carrier. As it turns out, electrons 28 00:01:45,600 --> 00:01:49,920 Speaker 1: are the naturally occurring negatively charged particles sub atomic particles 29 00:01:49,960 --> 00:01:55,800 Speaker 1: that are concerned, especially with electronics. So it's understandable, but 30 00:01:55,840 --> 00:01:57,520 Speaker 1: I just want to point that out that it's really 31 00:01:57,560 --> 00:01:59,920 Speaker 1: more about electric charge and less about the actual sub 32 00:02:00,000 --> 00:02:04,440 Speaker 1: stomic particles. Uh, don't worry, even though we'll be talking 33 00:02:04,600 --> 00:02:08,160 Speaker 1: a lot about electrons. I promise this show won't be 34 00:02:08,280 --> 00:02:12,200 Speaker 1: too negative. And I'm seriously done with puns for just 35 00:02:12,240 --> 00:02:15,640 Speaker 1: a bit now. To further define electricity, it helps if 36 00:02:15,639 --> 00:02:18,280 Speaker 1: we get some basic ideas established. Now, keep in mind 37 00:02:18,639 --> 00:02:22,080 Speaker 1: these aspects of electricity were not understood for centuries. So 38 00:02:22,120 --> 00:02:25,480 Speaker 1: when I go into the history of electricity, remember that 39 00:02:25,919 --> 00:02:30,440 Speaker 1: for the vast majority of our experience working with and 40 00:02:30,480 --> 00:02:34,359 Speaker 1: trying to understand electricity, we did not have any knowledge 41 00:02:34,400 --> 00:02:41,639 Speaker 1: of the underpinning foundational physics. Right. We were making observations 42 00:02:41,919 --> 00:02:45,160 Speaker 1: and we were even building things that could take advantage 43 00:02:45,200 --> 00:02:48,360 Speaker 1: of this stuff, but we didn't actually understand what it 44 00:02:48,440 --> 00:02:50,080 Speaker 1: was doing or how it was working, which I always 45 00:02:50,080 --> 00:02:53,480 Speaker 1: find really fascinating, this idea that we can harness something 46 00:02:53,960 --> 00:02:57,280 Speaker 1: without fully understanding what it is and how it works. 47 00:02:58,040 --> 00:03:00,920 Speaker 1: But it's good for us, as in myself and you 48 00:03:00,960 --> 00:03:03,959 Speaker 1: guys the audience, to understand some of these basics before 49 00:03:04,000 --> 00:03:07,240 Speaker 1: we get too far into the discussion. Otherwise I have 50 00:03:07,320 --> 00:03:11,240 Speaker 1: to keep interrupting the history lesson for science lessons, and 51 00:03:11,240 --> 00:03:14,280 Speaker 1: then it gets kind of a little complicated. Some of 52 00:03:14,280 --> 00:03:16,519 Speaker 1: that's gonna happen anyway, but I want to get the 53 00:03:16,560 --> 00:03:23,720 Speaker 1: foundation out of the way. So the most important thing 54 00:03:23,800 --> 00:03:27,160 Speaker 1: to remember here is that we're talking electric charge, and 55 00:03:27,200 --> 00:03:29,480 Speaker 1: we want to make sure we can make sense of this. 56 00:03:29,639 --> 00:03:32,760 Speaker 1: It's time to get current on our terms. So I 57 00:03:32,800 --> 00:03:36,680 Speaker 1: guess that really wasn't the last pun I'll be talking about. 58 00:03:36,680 --> 00:03:40,360 Speaker 1: So electric charge comes in two flavors, positive and negative, 59 00:03:40,640 --> 00:03:43,640 Speaker 1: positive charge and negative charge. You're probably very familiar with 60 00:03:43,720 --> 00:03:47,240 Speaker 1: us on the sub atomic particle level. Pot you know, 61 00:03:47,320 --> 00:03:50,200 Speaker 1: we have we have our our protons those are positively charged. 62 00:03:50,480 --> 00:03:53,680 Speaker 1: We have our electrons, those are negatively charged. Now, opposite 63 00:03:53,760 --> 00:03:58,560 Speaker 1: charges attract one another in circuits. A carrier moves negative 64 00:03:58,640 --> 00:04:02,720 Speaker 1: charges to a source of positive charge. So some sort 65 00:04:02,880 --> 00:04:07,760 Speaker 1: of subatomic particle needs to carry that negative charge throughout 66 00:04:07,760 --> 00:04:10,000 Speaker 1: the circuit until it can get to the source of 67 00:04:10,040 --> 00:04:14,280 Speaker 1: a positive charge. Because negative quote unquote wants to be 68 00:04:14,400 --> 00:04:17,839 Speaker 1: with positive. It doesn't really want anything, it's just that's 69 00:04:17,880 --> 00:04:22,320 Speaker 1: the natural tendency, right these for these two different charges 70 00:04:22,360 --> 00:04:26,520 Speaker 1: to attract one another. Now, in practical terms, the carrier 71 00:04:26,640 --> 00:04:29,599 Speaker 1: is an electron. So that's why we talk about electricity. 72 00:04:29,600 --> 00:04:33,760 Speaker 1: It's when we talk about electronics. Um it's the subatomic 73 00:04:33,760 --> 00:04:36,640 Speaker 1: particle that possesses negative charge. So if we do a 74 00:04:36,760 --> 00:04:41,200 Speaker 1: basic electrostatic experiment where we take a block of wax 75 00:04:41,600 --> 00:04:43,880 Speaker 1: and we rub that block of wax with some wool, 76 00:04:44,600 --> 00:04:47,560 Speaker 1: we will build up an electrostatic charge. So what's happening 77 00:04:47,600 --> 00:04:51,159 Speaker 1: is we are imparting a negative charge to the wax 78 00:04:52,240 --> 00:04:55,120 Speaker 1: and creating a positive charge to the wool. So, in 79 00:04:55,120 --> 00:04:58,080 Speaker 1: practical terms, that means the wax has a surplus of 80 00:04:58,120 --> 00:05:02,680 Speaker 1: electrons and the wool has a efficiency of electrons. Effectively, 81 00:05:02,720 --> 00:05:05,160 Speaker 1: you are rubbing some of the electrons from the wool 82 00:05:05,320 --> 00:05:07,960 Speaker 1: onto the wax. That makes the overall charge of the 83 00:05:07,960 --> 00:05:10,359 Speaker 1: surface of the wax negative. It makes the overall charge 84 00:05:10,400 --> 00:05:13,400 Speaker 1: of the surface of the wool positive. And if we 85 00:05:13,480 --> 00:05:17,640 Speaker 1: create a pathway that electrons can follow from the wax 86 00:05:18,160 --> 00:05:22,440 Speaker 1: to the wool, then electrons will take that pathway, pop 87 00:05:22,440 --> 00:05:26,039 Speaker 1: back over to the wool and sort of repair that 88 00:05:26,200 --> 00:05:31,760 Speaker 1: deficiency where that that deficiency of electrons will be balanced out, 89 00:05:31,800 --> 00:05:35,560 Speaker 1: where electrons will journey back over and rejoin, and they'll 90 00:05:35,600 --> 00:05:37,839 Speaker 1: probably be a big party, you know, or at least 91 00:05:37,839 --> 00:05:43,760 Speaker 1: a subatomic one. And that's that's the basics for electric charge. 92 00:05:43,920 --> 00:05:47,880 Speaker 1: So now we have to build on this foundation. There 93 00:05:47,920 --> 00:05:51,440 Speaker 1: are three other basic concepts that we need to understand, 94 00:05:51,960 --> 00:05:56,720 Speaker 1: and those are voltage, current, and resistance. Now these will 95 00:05:56,760 --> 00:05:59,680 Speaker 1: be important throughout the discussion of electricity, particularly as people 96 00:05:59,800 --> 00:06:02,920 Speaker 1: begin to get a deeper understanding of what was actually 97 00:06:02,960 --> 00:06:07,359 Speaker 1: happening with electricity. Voltage is probably the trickiest one for 98 00:06:07,400 --> 00:06:11,960 Speaker 1: people who aren't inclined toward electronics and electricity. It's all 99 00:06:12,000 --> 00:06:15,640 Speaker 1: about potential energy, specifically the potential energy represented by a 100 00:06:15,680 --> 00:06:20,599 Speaker 1: pair of different electric charges. So voltage is sort of 101 00:06:20,640 --> 00:06:23,560 Speaker 1: like pressure. You can imagine it as a force that 102 00:06:23,720 --> 00:06:28,000 Speaker 1: pushes electrons through a conductor, which is oversimplifying, but it's 103 00:06:28,040 --> 00:06:30,680 Speaker 1: helpful when you imagine it that way. So voltage is 104 00:06:30,720 --> 00:06:34,240 Speaker 1: the pressure in the system. The higher the voltage, the 105 00:06:34,320 --> 00:06:38,280 Speaker 1: greater the pressure, the stronger that push is. A low 106 00:06:38,400 --> 00:06:41,520 Speaker 1: voltage has very little push, while high voltage has a 107 00:06:41,560 --> 00:06:44,240 Speaker 1: whole lot of push, And we need voltage to make 108 00:06:44,240 --> 00:06:47,800 Speaker 1: electronics work. Otherwise nothing is going to cause a current 109 00:06:47,800 --> 00:06:50,760 Speaker 1: to flow through a circuit. You can also kind of 110 00:06:50,760 --> 00:06:53,479 Speaker 1: think of it as like potential energy in the form 111 00:06:53,680 --> 00:06:58,200 Speaker 1: of as an analogy of kinetic energy. So let's say 112 00:06:58,200 --> 00:07:00,760 Speaker 1: that you have a level surface pond which you've got 113 00:07:00,760 --> 00:07:05,159 Speaker 1: a two little corrals of marbles. They don't really have 114 00:07:05,200 --> 00:07:07,680 Speaker 1: any potential energy with respect to one another. They're on 115 00:07:07,720 --> 00:07:10,080 Speaker 1: the same level. But let's say you raise one of 116 00:07:10,120 --> 00:07:11,800 Speaker 1: those up, you tilt it, and you raise it up, 117 00:07:11,800 --> 00:07:14,520 Speaker 1: so the corral is still holding the marble's in. But 118 00:07:14,720 --> 00:07:17,200 Speaker 1: now the marbles have potential energy because they're at a 119 00:07:17,280 --> 00:07:20,880 Speaker 1: higher level than the lower marbles. And then let's say 120 00:07:20,920 --> 00:07:23,960 Speaker 1: you were to connect a little slide between the top 121 00:07:24,040 --> 00:07:26,760 Speaker 1: corral and the bottom corral and allow the marbles to 122 00:07:26,960 --> 00:07:30,240 Speaker 1: roll down the hill. Well, this would be sort of 123 00:07:30,320 --> 00:07:35,960 Speaker 1: like a copper wire connecting an area that has a 124 00:07:36,040 --> 00:07:39,160 Speaker 1: surplus of electrons to an area that has a deficiency 125 00:07:39,200 --> 00:07:45,240 Speaker 1: of electrons. It's allowing for the movement of those electrons. Now, 126 00:07:45,280 --> 00:07:48,600 Speaker 1: in the case of voltage, we're really talking about electric 127 00:07:48,640 --> 00:07:53,280 Speaker 1: potential here. We're not talking about kinetic energy or potential 128 00:07:53,360 --> 00:07:56,640 Speaker 1: energy that can be converted into kinetic energy. Is really 129 00:07:56,640 --> 00:07:59,640 Speaker 1: just meant as an analogy. So when we talk about 130 00:07:59,720 --> 00:08:02,440 Speaker 1: volta age, we talk about it with respect of two 131 00:08:02,480 --> 00:08:06,119 Speaker 1: points on a circuit. So a voltage difference between two 132 00:08:06,120 --> 00:08:09,880 Speaker 1: points on a single circuit and their potential difference really 133 00:08:09,920 --> 00:08:13,400 Speaker 1: which we may also call a voltage drop. The potential 134 00:08:13,400 --> 00:08:17,160 Speaker 1: difference between two points is measured in a unit called volts. 135 00:08:17,640 --> 00:08:20,040 Speaker 1: No big surprise there. A volt is the amount of 136 00:08:20,120 --> 00:08:23,560 Speaker 1: energy needed to force an electrical current of one ampier 137 00:08:24,000 --> 00:08:26,480 Speaker 1: more on that in a second, through a resistance of 138 00:08:26,600 --> 00:08:29,640 Speaker 1: one ohm more on that in a second, to at 139 00:08:29,640 --> 00:08:32,800 Speaker 1: a particular temperature. Now, you can have a voltage between 140 00:08:32,840 --> 00:08:36,439 Speaker 1: two points without having any connection between them. So you 141 00:08:36,480 --> 00:08:38,920 Speaker 1: can have a voltage between two things that do not 142 00:08:39,040 --> 00:08:43,319 Speaker 1: have an active pathway between the two. If the distance 143 00:08:43,520 --> 00:08:50,079 Speaker 1: between the two points is decreased, then that electrostatic field 144 00:08:50,280 --> 00:08:56,479 Speaker 1: that the voltage difference creates will intensify. If you increase 145 00:08:56,600 --> 00:09:01,760 Speaker 1: the space between those two points, the electrostatic yield will diminish. 146 00:09:02,200 --> 00:09:05,880 Speaker 1: So distance plays a factor, not just the difference in voltage. 147 00:09:06,200 --> 00:09:10,320 Speaker 1: So that covers voltage. But now let's talk about current. 148 00:09:11,040 --> 00:09:14,360 Speaker 1: So technically the current is a flow of electrical charge, 149 00:09:14,400 --> 00:09:17,920 Speaker 1: and we commonly think of it as the movement of electrons, 150 00:09:17,960 --> 00:09:20,880 Speaker 1: but again that's an oversimplification. You can actually have a 151 00:09:20,960 --> 00:09:24,200 Speaker 1: flow of positive charge and that would still be a current. 152 00:09:24,840 --> 00:09:27,280 Speaker 1: If you add a flow of positive charge, that's technically 153 00:09:27,280 --> 00:09:30,480 Speaker 1: a current. But when we're talking about circuits and electronics, 154 00:09:30,480 --> 00:09:36,240 Speaker 1: were really talking about electrons, not positively charged electrical charges. 155 00:09:36,840 --> 00:09:39,599 Speaker 1: So we tend to simplify it and say it's the 156 00:09:39,640 --> 00:09:42,000 Speaker 1: flow of electrons. Just keep in mind that that is 157 00:09:42,040 --> 00:09:46,760 Speaker 1: an oversimplification, uh, because electrons are the charge carriers of 158 00:09:46,800 --> 00:09:50,240 Speaker 1: negative charge. Now, in a way, you could think of 159 00:09:50,280 --> 00:09:53,480 Speaker 1: it as electrons are the messengers and the electric charge 160 00:09:53,520 --> 00:09:56,640 Speaker 1: they carry is the message, and that's what's really important. 161 00:09:56,720 --> 00:10:00,400 Speaker 1: But in practical terms, we can just so aplify it 162 00:10:00,440 --> 00:10:05,160 Speaker 1: to electrons. We measure current in ampiers, uh, and that 163 00:10:05,280 --> 00:10:08,400 Speaker 1: gives us a sense of the intensity or quantity of 164 00:10:08,559 --> 00:10:13,840 Speaker 1: a charge. So voltage is the force behind moving a charge, 165 00:10:13,880 --> 00:10:17,720 Speaker 1: and amperage tells you how much charge is actually moving. 166 00:10:18,320 --> 00:10:20,840 Speaker 1: And this can help if you start to imagine voltage 167 00:10:20,880 --> 00:10:24,640 Speaker 1: as being a locomotive engine and the amperage as being 168 00:10:24,720 --> 00:10:28,320 Speaker 1: a series of train cars. So a low amperage current 169 00:10:28,520 --> 00:10:30,320 Speaker 1: you might think of as just being two or three 170 00:10:30,360 --> 00:10:35,040 Speaker 1: train cars being pushed by a locomotive engine, but you 171 00:10:35,120 --> 00:10:38,720 Speaker 1: might think of high amperage as being a series of 172 00:10:38,760 --> 00:10:41,880 Speaker 1: train cars like fifteen or twenty being pushed by that 173 00:10:42,040 --> 00:10:45,679 Speaker 1: same locomotive engine. In both cases, the locomotive engine is 174 00:10:45,720 --> 00:10:49,480 Speaker 1: putting out the same amount of force. It's just that 175 00:10:49,559 --> 00:10:53,640 Speaker 1: in one case it's pushing a relatively small number of 176 00:10:53,679 --> 00:10:56,240 Speaker 1: train cars and the other one that's pushing a larger number. 177 00:10:56,320 --> 00:10:58,240 Speaker 1: But the amount of force it's using for both is 178 00:10:58,280 --> 00:11:03,000 Speaker 1: the same. So that's the difference between current and voltage, 179 00:11:03,440 --> 00:11:08,920 Speaker 1: or if you prefer amperage and volts. Uh. Now, current 180 00:11:09,000 --> 00:11:11,280 Speaker 1: will get a bit more confusing when we start talking 181 00:11:11,320 --> 00:11:14,280 Speaker 1: about the direction of flow. And that's thanks to a 182 00:11:14,360 --> 00:11:17,760 Speaker 1: certain founding father of the United States. But I don't 183 00:11:17,800 --> 00:11:19,920 Speaker 1: want to jump ahead. We'll get there when we get there. 184 00:11:20,360 --> 00:11:23,560 Speaker 1: I'll save that for a little bit later in this episode. Finally, 185 00:11:23,679 --> 00:11:27,000 Speaker 1: we have the concept of resistance, and as the name suggests, 186 00:11:27,000 --> 00:11:29,640 Speaker 1: this is the property of a material to resist the 187 00:11:29,679 --> 00:11:33,200 Speaker 1: flow of electric charge. A material with a very high 188 00:11:33,320 --> 00:11:36,400 Speaker 1: resistance is an insulator. It does not allow electric charge 189 00:11:36,440 --> 00:11:38,400 Speaker 1: to pass through it very easily. You would have to 190 00:11:38,480 --> 00:11:41,280 Speaker 1: use a great deal of energy to move an electric 191 00:11:41,360 --> 00:11:44,520 Speaker 1: charge through that kind of material. A material with very 192 00:11:44,520 --> 00:11:48,079 Speaker 1: low resistance is a conductor. It will allow electric charge 193 00:11:48,120 --> 00:11:52,520 Speaker 1: to flow through relatively easily. Now, even conductors have resistance. 194 00:11:53,440 --> 00:11:57,520 Speaker 1: You have to get to very low temperatures, like super 195 00:11:57,760 --> 00:12:00,960 Speaker 1: frozen temperatures almost close to absolute zero to get to 196 00:12:01,360 --> 00:12:05,200 Speaker 1: super conductivity, where you have zero resistance and a conductor 197 00:12:05,240 --> 00:12:09,240 Speaker 1: becomes an ideal or perfect conductor. But at other temperatures 198 00:12:09,280 --> 00:12:12,560 Speaker 1: there's some resistance. You can get around that by making 199 00:12:12,679 --> 00:12:17,360 Speaker 1: a cable thicker. Thin cables have a higher resistance than 200 00:12:17,400 --> 00:12:21,280 Speaker 1: thicker cables. But that's kind of beyond what we're talking 201 00:12:21,320 --> 00:12:26,600 Speaker 1: about here. We measure resistance in Ohms and Ohm. George Home, 202 00:12:26,760 --> 00:12:30,480 Speaker 1: who is a physician who kind of figured all this 203 00:12:30,520 --> 00:12:34,000 Speaker 1: stuff out, uh, developed Ohm's law. Now that tells us 204 00:12:34,000 --> 00:12:37,440 Speaker 1: that voltage is equal to current times resistance, or you 205 00:12:37,480 --> 00:12:41,080 Speaker 1: could say current is equal to voltage divided by resistance, 206 00:12:41,160 --> 00:12:44,280 Speaker 1: or that resistance is equal to voltage divided by current. 207 00:12:44,760 --> 00:12:49,040 Speaker 1: It's this relationship between current, resistance and voltage that is 208 00:12:49,559 --> 00:12:55,880 Speaker 1: inherent in electricity and electronics. Now, those basic concepts are 209 00:12:55,920 --> 00:12:59,480 Speaker 1: the very foundation for all electronics. Now, obviously it gets 210 00:12:59,480 --> 00:13:02,920 Speaker 1: more comp located. Uh, and you can add in all 211 00:13:02,920 --> 00:13:05,760 Speaker 1: sorts of different elements besides that, with like diodes and 212 00:13:05,760 --> 00:13:07,440 Speaker 1: things of that nature. But I just wanted to get 213 00:13:07,480 --> 00:13:11,600 Speaker 1: that covered as the basis for the conversation that follows. 214 00:13:12,080 --> 00:13:14,880 Speaker 1: And now we're going to dive into a history lesson. 215 00:13:15,600 --> 00:13:21,040 Speaker 1: So humans have known about electricity in some form for millennia. 216 00:13:21,360 --> 00:13:25,000 Speaker 1: Fails of melitas, and I know I mispronouncing that, So 217 00:13:25,040 --> 00:13:29,200 Speaker 1: to all my my Greek historians out there, I deeply apologize, 218 00:13:29,240 --> 00:13:33,400 Speaker 1: but I have little Latin and less Greek. Along with 219 00:13:33,440 --> 00:13:38,280 Speaker 1: my my buddy Shakespeare. Anyway, he had noted that amber, 220 00:13:38,640 --> 00:13:43,280 Speaker 1: the material amber, would attract light materials to its surface 221 00:13:43,320 --> 00:13:45,600 Speaker 1: after being rubbed. So if you rubbed amber with a 222 00:13:45,640 --> 00:13:48,520 Speaker 1: cloth and then held it towards feathers, for example, you 223 00:13:48,559 --> 00:13:50,520 Speaker 1: would notice that feathers would have a tendency to be 224 00:13:50,640 --> 00:13:55,040 Speaker 1: attracted to the amber. Now, later on we would understand 225 00:13:55,080 --> 00:13:58,400 Speaker 1: that this is static electricity, this is building an electrostatic 226 00:13:58,559 --> 00:14:02,080 Speaker 1: charge using amber. But this was more of an observation 227 00:14:02,120 --> 00:14:06,560 Speaker 1: back in those times and and this centuries before uh 228 00:14:06,600 --> 00:14:11,319 Speaker 1: the common era. And in fact, the word electricity comes 229 00:14:11,360 --> 00:14:13,960 Speaker 1: from the Latin electron, which in turn comes from the 230 00:14:14,040 --> 00:14:19,000 Speaker 1: Greek electron, which means amber. So when we talked about electrons, 231 00:14:19,920 --> 00:14:23,040 Speaker 1: that means that's the Greek word for amber. And it's 232 00:14:23,080 --> 00:14:26,520 Speaker 1: because of this initial well not even initial, but this 233 00:14:26,680 --> 00:14:30,480 Speaker 1: early observation. I just thought that was kind of interesting, 234 00:14:31,640 --> 00:14:37,280 Speaker 1: and you would eventually learned that a future engineer. Scientists 235 00:14:37,920 --> 00:14:43,000 Speaker 1: named this whole process electricity in honor of this early observation. 236 00:14:43,680 --> 00:14:47,080 Speaker 1: Now in nineteen thirty six, we're jumping ahead just to 237 00:14:47,120 --> 00:14:52,360 Speaker 1: talk about another discovery about ancient civilizations. There was a 238 00:14:52,680 --> 00:14:59,240 Speaker 1: railroad project that ended up excavating some um some ruins 239 00:14:59,480 --> 00:15:03,480 Speaker 1: southeast to Baghdad, and they revealed what we have commonly 240 00:15:03,560 --> 00:15:07,760 Speaker 1: referred to as the Baghdad batteries. These were vessels that 241 00:15:07,800 --> 00:15:11,280 Speaker 1: appeared to have been designed specifically to generate electricity, at 242 00:15:11,320 --> 00:15:16,440 Speaker 1: least that's one of the hypotheses about these uh, these vessels. 243 00:15:16,480 --> 00:15:20,560 Speaker 1: Some people disagree, but it's a very popular one. Now 244 00:15:20,600 --> 00:15:23,440 Speaker 1: you probably have heard about this in some form of 245 00:15:23,480 --> 00:15:26,280 Speaker 1: another or another. You may have even seen the MythBusters 246 00:15:26,280 --> 00:15:29,360 Speaker 1: episode where they talked about this. The team and MythBusters 247 00:15:29,360 --> 00:15:32,160 Speaker 1: talked about the possible applications for these so called batteries, 248 00:15:32,200 --> 00:15:35,520 Speaker 1: which could include a thing that you would use in 249 00:15:35,600 --> 00:15:41,360 Speaker 1: religious ceremonies where you would have these metal coded vessels 250 00:15:41,400 --> 00:15:43,760 Speaker 1: that if you were to touch them, you would create 251 00:15:43,920 --> 00:15:46,800 Speaker 1: a circuit and you would allow electricity to flow through 252 00:15:46,840 --> 00:15:49,720 Speaker 1: you and that would create a tingling or numbing sensation 253 00:15:49,760 --> 00:15:53,200 Speaker 1: in your hands, thus akin to some sort of mystical 254 00:15:53,280 --> 00:15:57,000 Speaker 1: experience and thus being part of a religious experience. Or 255 00:15:58,200 --> 00:16:00,600 Speaker 1: it could be that it was more of a practical 256 00:16:01,800 --> 00:16:06,520 Speaker 1: approach toward something like electro plating, and I thought that 257 00:16:06,600 --> 00:16:08,840 Speaker 1: was really cool. So let's talk about what electroplating is, 258 00:16:08,880 --> 00:16:12,400 Speaker 1: because otherwise, you know, it doesn't really mean anything to you. 259 00:16:12,960 --> 00:16:16,680 Speaker 1: As the name implies, electroplating involves using electricity to cover 260 00:16:16,920 --> 00:16:22,320 Speaker 1: or plate one material with another material. Typically you are 261 00:16:22,520 --> 00:16:26,080 Speaker 1: plating one type of metal, not necessarily metal, but the 262 00:16:26,120 --> 00:16:30,280 Speaker 1: early version of electro plating was metal, but one type 263 00:16:30,280 --> 00:16:34,520 Speaker 1: of metal with a more precious metal. So the reason 264 00:16:34,560 --> 00:16:38,239 Speaker 1: you might do this is to make really pretty expensive 265 00:16:38,360 --> 00:16:42,720 Speaker 1: looking stuff without using too much of the actual precious material. 266 00:16:43,520 --> 00:16:46,240 Speaker 1: So you might gold plate a copper bowl, for example, 267 00:16:46,320 --> 00:16:49,440 Speaker 1: because you want the gold bowl. Gold is more precious 268 00:16:49,440 --> 00:16:52,240 Speaker 1: than copper, but you don't want to actually have to 269 00:16:52,280 --> 00:16:54,320 Speaker 1: go out and dig as much gold as you would 270 00:16:54,320 --> 00:16:56,240 Speaker 1: need to build a gold bowl, so you want to 271 00:16:56,240 --> 00:17:00,600 Speaker 1: plate the copper bowl with gold. That way, it looks 272 00:17:00,800 --> 00:17:03,000 Speaker 1: exactly the way you wanted to, but you didn't have 273 00:17:03,080 --> 00:17:05,760 Speaker 1: to spend all that time and effort getting all that gold. 274 00:17:05,760 --> 00:17:08,720 Speaker 1: In other words, we can thank the laziness and greed 275 00:17:08,800 --> 00:17:11,800 Speaker 1: of human beings for some of the early advances as 276 00:17:11,840 --> 00:17:16,800 Speaker 1: far as electricity is concerned, So you might want to 277 00:17:16,880 --> 00:17:19,840 Speaker 1: use electroplating to do that. We also use electroplating for 278 00:17:19,880 --> 00:17:23,960 Speaker 1: other purposes, like putting rust resistant coatings onto stuff that 279 00:17:24,000 --> 00:17:27,159 Speaker 1: otherwise would corrode. Uh. You can also use it to 280 00:17:27,160 --> 00:17:32,280 Speaker 1: produce alloys like bronze and brass. But let's go back 281 00:17:32,280 --> 00:17:35,560 Speaker 1: to electroplating. So let's say these ancient people were using 282 00:17:35,920 --> 00:17:39,359 Speaker 1: the so called Bagdad batteries in order to electroplate gold 283 00:17:39,359 --> 00:17:42,760 Speaker 1: onto copper. How would you do this well, First you 284 00:17:42,800 --> 00:17:45,160 Speaker 1: have to make sure that the copper is totally clean, 285 00:17:45,400 --> 00:17:48,760 Speaker 1: because if it has any Schmutz on it, the gold 286 00:17:48,760 --> 00:17:51,760 Speaker 1: will not properly adhere to the copper and it'll flake off. 287 00:17:52,680 --> 00:17:58,040 Speaker 1: So you typically would clean copper this way by dipping 288 00:17:58,080 --> 00:18:01,600 Speaker 1: it in a solution that either is a really powerful 289 00:18:01,640 --> 00:18:05,159 Speaker 1: alkaline solution or a very powerful acidic solution to to 290 00:18:05,280 --> 00:18:08,440 Speaker 1: truly clean it. Once you did that, you would then 291 00:18:08,600 --> 00:18:12,359 Speaker 1: attach a conductor from the battery to the copper that 292 00:18:12,400 --> 00:18:15,840 Speaker 1: you're playing on on electroplating. So if it's a bowl, 293 00:18:16,119 --> 00:18:18,440 Speaker 1: then you would want to make sure that the terminal, 294 00:18:18,720 --> 00:18:23,680 Speaker 1: the proper terminal from the Baghdad battery is in contact 295 00:18:23,920 --> 00:18:28,160 Speaker 1: with that copper bowl. Then you would put that whole thing, 296 00:18:28,280 --> 00:18:32,600 Speaker 1: the copper bowl with the um the terminal into an 297 00:18:32,640 --> 00:18:36,359 Speaker 1: electro light solution, which is in this case a gold 298 00:18:36,359 --> 00:18:40,239 Speaker 1: based electro light, so you have gold particles within the 299 00:18:40,320 --> 00:18:44,119 Speaker 1: electrolyte itself. Now electrolytes, by the way, our materials that 300 00:18:44,240 --> 00:18:48,240 Speaker 1: dissociate into ions when dissolved in a suitable medium and 301 00:18:48,280 --> 00:18:52,520 Speaker 1: become a conductor of electricity. So ions, of course, are 302 00:18:52,520 --> 00:18:56,320 Speaker 1: are our variations of atoms that have a net charge 303 00:18:56,520 --> 00:18:59,040 Speaker 1: on them. They're not neutral. They have either a net 304 00:18:59,040 --> 00:19:02,159 Speaker 1: negative or a net positive charge. So when you do this, 305 00:19:02,240 --> 00:19:06,520 Speaker 1: you've got your gold ions in this electrolyte solution. You 306 00:19:07,040 --> 00:19:10,919 Speaker 1: then put the electrodes together so that not together, but 307 00:19:11,000 --> 00:19:14,080 Speaker 1: within the solution, so that a current can pass through 308 00:19:15,000 --> 00:19:18,760 Speaker 1: the electrodes. Allow the current to go through the electrolight 309 00:19:18,880 --> 00:19:23,640 Speaker 1: into the other terminal or the other electrode, and you've 310 00:19:23,640 --> 00:19:26,199 Speaker 1: got a negative in a positive electrode. So when the 311 00:19:26,200 --> 00:19:28,879 Speaker 1: current passes through the electro light, the electrolyte splits up 312 00:19:28,880 --> 00:19:31,800 Speaker 1: and some of the metal atoms contained within the electrolyte 313 00:19:31,800 --> 00:19:34,720 Speaker 1: are deposited on one of the two electrodes that you 314 00:19:34,760 --> 00:19:37,720 Speaker 1: inserted into the electrolyte. So what's really happening is the 315 00:19:37,760 --> 00:19:40,600 Speaker 1: metal atoms are ions. They hold that charge. They're attracted 316 00:19:40,640 --> 00:19:43,399 Speaker 1: to the electrode that has the opposite charge, and they 317 00:19:43,440 --> 00:19:47,320 Speaker 1: attached to it. So if you have a negatively charged 318 00:19:47,920 --> 00:19:52,280 Speaker 1: terminal and you have positively charged gold ions, that opposite 319 00:19:52,280 --> 00:19:55,679 Speaker 1: attract rule still takes place and the gold will plate 320 00:19:55,920 --> 00:20:02,200 Speaker 1: onto the copper electrode or bowl in this case, and 321 00:20:02,480 --> 00:20:04,879 Speaker 1: then you've got your gold plated copper thing of a 322 00:20:04,960 --> 00:20:07,920 Speaker 1: jig which is kind of cool. Now there's some who 323 00:20:07,920 --> 00:20:11,160 Speaker 1: put forth the hypothesis that perhaps ancient people has made 324 00:20:11,160 --> 00:20:14,840 Speaker 1: other uses of electricity, all the way up to even 325 00:20:14,880 --> 00:20:20,159 Speaker 1: powering lights in ancient Egypt, but most scholars that I 326 00:20:20,240 --> 00:20:28,119 Speaker 1: have consulted dismiss this as unrealistic. I haven't really seen 327 00:20:28,200 --> 00:20:32,440 Speaker 1: much evidence to support this apart from some circumstantial evidence. 328 00:20:32,440 --> 00:20:37,240 Speaker 1: Some supporters cite a hieroglyphic relief that shows what to 329 00:20:37,320 --> 00:20:41,359 Speaker 1: our modern eyes appears to be an enormous lightbulb, but 330 00:20:41,440 --> 00:20:45,640 Speaker 1: the accepted interpretation of that hieroglyph seems to be that 331 00:20:45,800 --> 00:20:48,560 Speaker 1: it's a lotus leaf with the figure of a snake 332 00:20:48,680 --> 00:20:53,000 Speaker 1: on it, not a huge ancient lightbulb. Still, it seems 333 00:20:53,000 --> 00:20:54,880 Speaker 1: that there was at least some knowledge of the existence 334 00:20:54,880 --> 00:20:57,760 Speaker 1: of electricity, if not what it actually could do or 335 00:20:57,800 --> 00:21:01,520 Speaker 1: what it was. Now that's a trend that would last 336 00:21:01,600 --> 00:21:05,200 Speaker 1: for centuries. In fact, we were making use of electricity 337 00:21:05,480 --> 00:21:08,080 Speaker 1: well before anyone really knew what was going on with it. 338 00:21:08,200 --> 00:21:10,560 Speaker 1: And again, to me, that is one of the phenomenal 339 00:21:10,560 --> 00:21:13,160 Speaker 1: things about human history is when we come across these 340 00:21:13,200 --> 00:21:16,679 Speaker 1: moments where people have figured out something or how to 341 00:21:16,800 --> 00:21:20,080 Speaker 1: use something without really fully understanding why it is that 342 00:21:20,119 --> 00:21:23,399 Speaker 1: could be dangerous. Clearly, there were plenty of cases of 343 00:21:23,440 --> 00:21:26,720 Speaker 1: that in the nineteen fifties with radiation, where people thought 344 00:21:27,119 --> 00:21:32,080 Speaker 1: that radiation didn't have any particular harmful effects. You might 345 00:21:32,080 --> 00:21:35,679 Speaker 1: have seen things about like using X rays in shoe 346 00:21:35,680 --> 00:21:38,679 Speaker 1: stores so that people could see their feet through the 347 00:21:38,760 --> 00:21:42,040 Speaker 1: shoes that they were trying on. And then only later 348 00:21:42,280 --> 00:21:45,000 Speaker 1: did we realize that X rays are an ionizing form 349 00:21:45,080 --> 00:21:47,880 Speaker 1: of radiation and that we probably should not or definitely 350 00:21:47,920 --> 00:21:50,840 Speaker 1: should not have been doing that. Um same sort of 351 00:21:50,840 --> 00:21:52,800 Speaker 1: thing with electricity. We were putting it to use before 352 00:21:52,840 --> 00:21:56,440 Speaker 1: we ever really understood what was going on there. Uh. 353 00:21:56,600 --> 00:21:59,320 Speaker 1: But of course electricity isn't ionizing radiation, so it does 354 00:21:59,400 --> 00:22:05,160 Speaker 1: have very different effects then radiation does. But what follows 355 00:22:05,200 --> 00:22:07,920 Speaker 1: is a brief history of the developments that unfolded as 356 00:22:08,040 --> 00:22:11,760 Speaker 1: very very smart people figured out what the heck electricity is. 357 00:22:12,240 --> 00:22:15,200 Speaker 1: So in the fifteen hundreds you had an English physician 358 00:22:15,320 --> 00:22:19,960 Speaker 1: and proto scientist named William Gilbert who began to experiment 359 00:22:20,000 --> 00:22:24,000 Speaker 1: with magnets and static electricity. So he used loadstone, which 360 00:22:24,040 --> 00:22:27,639 Speaker 1: is naturally magnetic iron ore, and he published his work 361 00:22:27,720 --> 00:22:32,840 Speaker 1: in sixteen hundred under the title De magnete or a 362 00:22:32,920 --> 00:22:38,040 Speaker 1: de magnet magneti. It's magneto but with a knee. He 363 00:22:38,119 --> 00:22:43,040 Speaker 1: was able to describe magnetism and static electricity as distinct phenomena, 364 00:22:43,200 --> 00:22:45,440 Speaker 1: though he wasn't really sure what was actually causing it. 365 00:22:45,760 --> 00:22:48,560 Speaker 1: His hypothesis was that there was some sort of fluid 366 00:22:48,960 --> 00:22:52,479 Speaker 1: or humor, as in the various humors of the body. 367 00:22:52,720 --> 00:22:56,520 Speaker 1: There was another prevailing physical theory at the time, and 368 00:22:56,560 --> 00:22:59,720 Speaker 1: that this was the cause of attraction with static electricity, 369 00:22:59,800 --> 00:23:02,000 Speaker 1: and that if you rubbed amber, what you were actually 370 00:23:02,000 --> 00:23:05,159 Speaker 1: doing was removing some of that fluid from the amber, 371 00:23:05,200 --> 00:23:09,239 Speaker 1: which created a hole or like a vacuum around it, 372 00:23:09,320 --> 00:23:12,080 Speaker 1: and this is why light objects would become attracted to 373 00:23:12,119 --> 00:23:16,320 Speaker 1: the amber. He called it a fluvium and described it 374 00:23:16,400 --> 00:23:22,399 Speaker 1: as an electric effect. In sixteen sixty an inventor named 375 00:23:22,400 --> 00:23:26,640 Speaker 1: Otto von Gerrika built a machine using a globe made 376 00:23:26,640 --> 00:23:29,639 Speaker 1: of sulfur, and if you rubbed the globe as it turned, 377 00:23:29,720 --> 00:23:33,080 Speaker 1: you could build up a charge, an electrostatic charge, causing 378 00:23:33,119 --> 00:23:35,639 Speaker 1: it to attract small light objects such as feathers or 379 00:23:35,640 --> 00:23:39,160 Speaker 1: scraps of paper. Garrika also observed that his invention would 380 00:23:39,200 --> 00:23:42,400 Speaker 1: cause a spark if you rubbed the globe for long enough. 381 00:23:42,480 --> 00:23:46,719 Speaker 1: You could then touch something metal like a brass knob 382 00:23:47,080 --> 00:23:51,600 Speaker 1: and see a spark fly between the electrostatically charged object 383 00:23:51,640 --> 00:23:57,000 Speaker 1: and the grounded piece of metal. Stephen Gray, another English scientist, 384 00:23:57,080 --> 00:23:59,960 Speaker 1: observed in seventeen twenty nine that some stuff doesn't can 385 00:24:00,040 --> 00:24:03,200 Speaker 1: duct electricity at all. So he thought some materials would 386 00:24:03,240 --> 00:24:07,200 Speaker 1: allow the fluid of electricity to flow through and other 387 00:24:07,600 --> 00:24:11,920 Speaker 1: materials would hamper the flow of this fluid electricity, which 388 00:24:11,960 --> 00:24:15,000 Speaker 1: is sort of true when you get to electrical resistance, 389 00:24:15,040 --> 00:24:19,320 Speaker 1: only we're not talking about a fluid really. Later that century, 390 00:24:19,520 --> 00:24:25,400 Speaker 1: Dutch inventor's Pietr von Musen book and evolved von Kleist 391 00:24:25,880 --> 00:24:28,960 Speaker 1: created what we now call the Layden jar, and there 392 00:24:28,960 --> 00:24:33,080 Speaker 1: are actually two variations on basic Layden jars, which store 393 00:24:33,200 --> 00:24:37,199 Speaker 1: electrostatic charges. They're essentially capacitors, So you build up an 394 00:24:37,200 --> 00:24:40,000 Speaker 1: electric static charge in this thing, and then when you 395 00:24:41,080 --> 00:24:46,520 Speaker 1: touch the the charged component, you allow that electro static 396 00:24:46,640 --> 00:24:52,040 Speaker 1: charge to discharge to spark um. So they release all 397 00:24:52,080 --> 00:24:56,240 Speaker 1: of that charged energy in an instant, unlike a battery, 398 00:24:56,320 --> 00:25:03,119 Speaker 1: which releases UH which which creates the voltage difference and 399 00:25:03,160 --> 00:25:06,600 Speaker 1: allows for electric electric current to flow over time. A 400 00:25:06,600 --> 00:25:11,800 Speaker 1: capacitor releases it in a in a a moment. There 401 00:25:11,800 --> 00:25:13,800 Speaker 1: are two basic versions of the Leyden jar, and the 402 00:25:13,840 --> 00:25:18,600 Speaker 1: first one uses a metal container inside which you have 403 00:25:18,840 --> 00:25:22,639 Speaker 1: a glass vessel nestled inside that metal container, and inside 404 00:25:22,640 --> 00:25:27,000 Speaker 1: the glass vessel you have a second metal container nestled 405 00:25:27,040 --> 00:25:29,600 Speaker 1: inside that. So it's kind of like a sandwich where 406 00:25:29,600 --> 00:25:33,800 Speaker 1: the bread is metal container and the and the meat 407 00:25:33,880 --> 00:25:38,359 Speaker 1: inside is glass. I don't recommend eating that sandwich, it 408 00:25:38,400 --> 00:25:43,040 Speaker 1: would not taste good and probably hurt you, but it 409 00:25:43,119 --> 00:25:48,040 Speaker 1: was that layer metal glass metal, and you would then 410 00:25:48,160 --> 00:25:50,760 Speaker 1: also have a rod of metal that would extend up 411 00:25:50,760 --> 00:25:55,600 Speaker 1: from the base of that interior lining. So imagine like 412 00:25:55,640 --> 00:26:00,399 Speaker 1: a column rising up from that internal metal cup inside 413 00:26:00,480 --> 00:26:02,679 Speaker 1: the glass vessel, which in turn is inside a larger 414 00:26:02,680 --> 00:26:07,760 Speaker 1: metal vessel. The second variation has a metal vessel filled 415 00:26:07,800 --> 00:26:10,919 Speaker 1: with a conductive fluid like water that's got a salt 416 00:26:10,960 --> 00:26:13,119 Speaker 1: dissolved in it. Water on in its own will conduct 417 00:26:13,160 --> 00:26:16,320 Speaker 1: electricity as long as it has some impurities in it, 418 00:26:16,359 --> 00:26:19,560 Speaker 1: but you can make it conduct electricity more effectively by 419 00:26:19,560 --> 00:26:22,840 Speaker 1: adding or doping the water with some of those impurities, 420 00:26:23,359 --> 00:26:25,160 Speaker 1: and it would have a metal rod sticking out from 421 00:26:25,160 --> 00:26:27,119 Speaker 1: the water. Now, both versions would allow you to do 422 00:26:27,280 --> 00:26:29,520 Speaker 1: essentially the same thing, which is store up that electro 423 00:26:29,520 --> 00:26:32,679 Speaker 1: static charge. And you do this by building up an 424 00:26:32,720 --> 00:26:36,920 Speaker 1: electric static charge in something else. So you might take 425 00:26:36,960 --> 00:26:39,720 Speaker 1: some amber, for example, and rub the amber. Then you 426 00:26:39,760 --> 00:26:43,400 Speaker 1: would bring that into contact with that metal bar that's 427 00:26:43,400 --> 00:26:47,440 Speaker 1: extending upward from the jar. That would introduce a charge 428 00:26:47,560 --> 00:26:52,320 Speaker 1: to one plate in this capacity, and that would create 429 00:26:52,359 --> 00:26:56,040 Speaker 1: the opposite charge in the opposing plate. Uh in this 430 00:26:56,080 --> 00:26:59,240 Speaker 1: case that exterior metal casing, you would need to ground 431 00:26:59,280 --> 00:27:01,520 Speaker 1: the outer metal case, which you could just do by 432 00:27:01,560 --> 00:27:04,800 Speaker 1: touching it yourself, or you could run a wire from 433 00:27:04,960 --> 00:27:08,879 Speaker 1: the exterior metal case to the ground or to a 434 00:27:08,920 --> 00:27:11,720 Speaker 1: metal pipe. And when you create a pathway between the 435 00:27:11,720 --> 00:27:14,480 Speaker 1: two plates by touching the charged rod, it creates a 436 00:27:14,520 --> 00:27:17,280 Speaker 1: spark as the charge is able to equalize, and that 437 00:27:17,320 --> 00:27:20,360 Speaker 1: could be a significant shock, depending on how much you've 438 00:27:20,359 --> 00:27:23,200 Speaker 1: built up inside this laden jar, to the point where 439 00:27:23,280 --> 00:27:27,360 Speaker 1: it could really hurt or possibly do serious damage. Both 440 00:27:27,440 --> 00:27:31,920 Speaker 1: Klaised and Moose musten Brook had shocking experiences with the 441 00:27:32,040 --> 00:27:34,960 Speaker 1: respective laden jars, and neither was really sure exactly what 442 00:27:35,040 --> 00:27:37,360 Speaker 1: was happening. Now we've got a lot ward to talk 443 00:27:37,400 --> 00:27:42,200 Speaker 1: about with the early discoveries surrounding electricity. But before we 444 00:27:42,560 --> 00:27:44,480 Speaker 1: get a charge out of all that, let's take a 445 00:27:44,560 --> 00:27:55,200 Speaker 1: quick break to thank our sponsors. All right, we're up 446 00:27:55,200 --> 00:27:59,800 Speaker 1: to seventeen fifty two, and that's when we revisit the 447 00:28:00,600 --> 00:28:05,000 Speaker 1: the great founding father I had mentioned earlier, Benjamin Franklin. 448 00:28:05,119 --> 00:28:09,600 Speaker 1: That's when we got the legendary experiments that Franklin conducted um. 449 00:28:09,640 --> 00:28:13,000 Speaker 1: He was friends with a scientist named Peter Collinson over 450 00:28:13,040 --> 00:28:18,400 Speaker 1: in Europe, and Collinson had sent Franklin and electricity tube. Franklin, 451 00:28:18,480 --> 00:28:21,280 Speaker 1: like his predecessors, thought electricity was a type of fluid, 452 00:28:21,600 --> 00:28:26,320 Speaker 1: and he hypothesized that lightning itself was an electric spark, 453 00:28:26,600 --> 00:28:29,280 Speaker 1: very much like the kind a latent jar could produce 454 00:28:29,440 --> 00:28:32,800 Speaker 1: if you built up enough of an electrostatic charge, and 455 00:28:32,960 --> 00:28:36,720 Speaker 1: thus charged forces would cause a lightning strike. And he 456 00:28:36,880 --> 00:28:40,760 Speaker 1: further hypothesized that you could use a metal rod to 457 00:28:41,040 --> 00:28:44,680 Speaker 1: draw lightning to a specific location, which could end up 458 00:28:45,000 --> 00:28:48,680 Speaker 1: saving structures from being struck by lightning. So if you 459 00:28:48,720 --> 00:28:50,320 Speaker 1: had a house and it got hit by lightning back 460 00:28:50,360 --> 00:28:54,080 Speaker 1: in those days, your house would very much be damaged, 461 00:28:54,120 --> 00:28:56,600 Speaker 1: possibly burned down as a result. So he thought, well, 462 00:28:56,640 --> 00:28:59,840 Speaker 1: maybe you could draw lightning away using long metal rods. 463 00:28:59,840 --> 00:29:03,240 Speaker 1: But problem was he couldn't build a metal rod tall 464 00:29:03,400 --> 00:29:06,680 Speaker 1: enough to dwarf the structures. He thought that he was 465 00:29:06,680 --> 00:29:09,160 Speaker 1: gonna have to build something that could almost reach the 466 00:29:09,160 --> 00:29:13,120 Speaker 1: skies themselves, which made it too big of a challenge. 467 00:29:14,160 --> 00:29:17,160 Speaker 1: Uh So he came up with this idea of using 468 00:29:17,200 --> 00:29:23,400 Speaker 1: a kite instead. Meanwhile, over in France, Thomas Francois d'allebard 469 00:29:23,760 --> 00:29:26,760 Speaker 1: decided to put Franklin's ideas to the test. He actually 470 00:29:26,800 --> 00:29:30,280 Speaker 1: constructed a large metal pole to try and conduct electricity 471 00:29:30,320 --> 00:29:33,200 Speaker 1: and declared that Franklin was absolutely right that in fact, 472 00:29:33,360 --> 00:29:37,240 Speaker 1: that metal rod does draw lightning. But this news didn't 473 00:29:37,280 --> 00:29:40,640 Speaker 1: travel back to America that fast. I mean, it took 474 00:29:40,640 --> 00:29:43,320 Speaker 1: a really long time for information to go from one 475 00:29:43,320 --> 00:29:48,320 Speaker 1: place to another, so Franklin was unaware that his hypothesis 476 00:29:48,320 --> 00:29:53,000 Speaker 1: had proven correct. So that same year, Franklin reportedly conducted 477 00:29:53,040 --> 00:29:56,959 Speaker 1: his experiment using a silk kite with a key tied 478 00:29:57,240 --> 00:30:01,640 Speaker 1: to the silk kite down to the string, and as 479 00:30:01,720 --> 00:30:04,400 Speaker 1: legend goes, he flew the kite up during a thunderstorm 480 00:30:04,480 --> 00:30:07,240 Speaker 1: until the key drew lightning to it, and then used 481 00:30:07,400 --> 00:30:11,200 Speaker 1: that key to charge a laden jar. So the electric 482 00:30:11,280 --> 00:30:14,120 Speaker 1: charge and the key was then transferred to a laden jar, 483 00:30:14,200 --> 00:30:18,400 Speaker 1: which again holds electrostatic charge. Now, I say reportedly because 484 00:30:18,480 --> 00:30:22,520 Speaker 1: Franklin's writings never outright said that that was what happened. 485 00:30:22,560 --> 00:30:27,200 Speaker 1: He never specifically said that he himself had performed the experiment. Now, 486 00:30:27,200 --> 00:30:29,520 Speaker 1: he did say that he did a simplified version of 487 00:30:29,560 --> 00:30:32,120 Speaker 1: this plan and that it happened in Philadelphia, But it's 488 00:30:32,200 --> 00:30:34,560 Speaker 1: unclear who was actually flying the kite at the time. 489 00:30:35,040 --> 00:30:38,600 Speaker 1: And according to modern scientists, if Franklin had conducted the 490 00:30:38,640 --> 00:30:42,440 Speaker 1: experiment as it has generally been reported, Franklin would have 491 00:30:42,480 --> 00:30:46,640 Speaker 1: been toasted. He would have been fried scientifically speaking. So 492 00:30:46,720 --> 00:30:52,000 Speaker 1: the general theory about this not scientific theory, but you know, 493 00:30:52,040 --> 00:30:54,600 Speaker 1: the general idea of what actually happened was that Franklin, 494 00:30:55,200 --> 00:30:58,160 Speaker 1: if he conducted the experiment at all, was able to 495 00:30:58,200 --> 00:31:01,320 Speaker 1: pick up an electrostatic charge by flying the kite near 496 00:31:01,360 --> 00:31:04,680 Speaker 1: a storm, but that the kite was never directly struck 497 00:31:04,720 --> 00:31:07,480 Speaker 1: by lightning. It just rather picked up a charge by 498 00:31:07,520 --> 00:31:12,520 Speaker 1: being lightning adjacent. I guess you could say, all quibbling aside. 499 00:31:12,560 --> 00:31:14,719 Speaker 1: By this time, it became established that lightning was in 500 00:31:14,760 --> 00:31:19,040 Speaker 1: fact a really big spark. Therefore, part of this concept 501 00:31:19,080 --> 00:31:22,720 Speaker 1: of electricity. Franklin made practical use out of this knowledge 502 00:31:22,760 --> 00:31:25,240 Speaker 1: by inventing the lightning rod. Now, the purpose of a 503 00:31:25,320 --> 00:31:27,520 Speaker 1: lightning rod is to attract a bolt of lightning to 504 00:31:27,600 --> 00:31:31,320 Speaker 1: the rod and then channel the electricity down to the ground. 505 00:31:32,280 --> 00:31:35,920 Speaker 1: Uh This spares structures from being hit by lightning and 506 00:31:35,960 --> 00:31:38,880 Speaker 1: thus being damaged. So your lightning rod typically has a 507 00:31:38,880 --> 00:31:41,880 Speaker 1: metal cable that extends down from the rod and then 508 00:31:42,560 --> 00:31:46,160 Speaker 1: is bury. It has like a conductive steak as well 509 00:31:46,200 --> 00:31:49,080 Speaker 1: that's buried in the ground and that channels the the 510 00:31:49,800 --> 00:31:53,280 Speaker 1: the current from the lightning down into the ground. Or 511 00:31:53,280 --> 00:31:56,600 Speaker 1: really it just gives the current a different direction to travel, honestly, 512 00:31:56,880 --> 00:31:59,320 Speaker 1: but if you look at lightning, current goes from the 513 00:31:59,320 --> 00:32:01,920 Speaker 1: ground up to the sky. It doesn't matter. The point 514 00:32:01,960 --> 00:32:03,600 Speaker 1: being that he was able to figure out a way 515 00:32:03,680 --> 00:32:08,480 Speaker 1: of sparing houses by using lightning rods. So he also 516 00:32:08,600 --> 00:32:12,320 Speaker 1: established something about electricity that vexes folks when they're first 517 00:32:12,520 --> 00:32:17,360 Speaker 1: learning about it. Franklin established electricity is having two natures. 518 00:32:17,360 --> 00:32:21,479 Speaker 1: He called it the resinous electricity, which he viewed as 519 00:32:21,520 --> 00:32:24,360 Speaker 1: a dip in the electric fluid from the normal amount 520 00:32:24,480 --> 00:32:27,000 Speaker 1: and thus negative. So this is where the charge is 521 00:32:27,040 --> 00:32:30,520 Speaker 1: flowing too. This would be akin to that idea of 522 00:32:30,520 --> 00:32:33,240 Speaker 1: a vacuum. You have a lack of something a hole, 523 00:32:33,920 --> 00:32:37,160 Speaker 1: and thus something else goes to fill the whole. Then 524 00:32:37,200 --> 00:32:40,560 Speaker 1: there was what he called vitreous electricity, which was an 525 00:32:40,560 --> 00:32:44,880 Speaker 1: excess of electric fluid and thus a positive amount. So 526 00:32:44,960 --> 00:32:49,640 Speaker 1: Franklin said, the movement of electricity goes from positive to negative. 527 00:32:50,320 --> 00:32:54,120 Speaker 1: You have an overabundance of this electric fluid, and it 528 00:32:54,160 --> 00:32:57,440 Speaker 1: moves to where you have a deficiency of electric fluid. 529 00:32:58,000 --> 00:33:03,080 Speaker 1: So the this is somewhat confusing if you're looking at 530 00:33:03,120 --> 00:33:08,160 Speaker 1: the scientific description of what's happening with your basic electric circuit, 531 00:33:08,560 --> 00:33:12,640 Speaker 1: where you're having negatively charged particles, that is, electrons go 532 00:33:12,920 --> 00:33:15,080 Speaker 1: from an area of high concentration to an area of 533 00:33:15,120 --> 00:33:19,680 Speaker 1: low concentration. It's the it's going from negative to positive, 534 00:33:20,040 --> 00:33:22,560 Speaker 1: not positive to negative. But it's because you're looking at 535 00:33:22,600 --> 00:33:25,440 Speaker 1: two different definitions of what is positive and what is negative. 536 00:33:25,840 --> 00:33:29,440 Speaker 1: That's where the real confusion lies. Uh So, when we 537 00:33:29,520 --> 00:33:34,000 Speaker 1: talk about electronics and we talk about electron flow and 538 00:33:34,040 --> 00:33:37,680 Speaker 1: we're looking at it purely from a charge perspective, we're 539 00:33:37,720 --> 00:33:43,160 Speaker 1: looking at negative particles moving towards a positive side. But 540 00:33:43,240 --> 00:33:45,360 Speaker 1: let's make it even more confusing than that. There are 541 00:33:45,360 --> 00:33:48,920 Speaker 1: really two major ways to illustrate charge flow in circuits. 542 00:33:49,840 --> 00:33:52,720 Speaker 1: One of them is called conventional flow notation, which is 543 00:33:52,760 --> 00:33:56,560 Speaker 1: the way electrical engineers tend to describe electrical flow, and 544 00:33:56,640 --> 00:34:02,600 Speaker 1: this follows Franklin's approach. It goes from positive to negative, 545 00:34:02,680 --> 00:34:05,480 Speaker 1: so electricity flows from the positive terminal to the negative 546 00:34:05,560 --> 00:34:10,759 Speaker 1: terminal because we're talking about the surplus of electrons to 547 00:34:10,880 --> 00:34:13,880 Speaker 1: the deficiency of electrons. We're not talking about the the 548 00:34:13,920 --> 00:34:17,480 Speaker 1: electric charge, we're talking about the number. There's more electrons 549 00:34:17,520 --> 00:34:21,120 Speaker 1: over here than they're over there, so that's why this 550 00:34:21,160 --> 00:34:23,880 Speaker 1: is gonna be the positive terminal with more electrons and 551 00:34:23,920 --> 00:34:26,719 Speaker 1: the negative terminal has fewer electrons because we're talking about 552 00:34:26,719 --> 00:34:32,279 Speaker 1: surplus and deficiency. But there's also electron flow notation now 553 00:34:32,320 --> 00:34:35,440 Speaker 1: that one looks at the actual charges, not the numbers. 554 00:34:35,920 --> 00:34:38,520 Speaker 1: So in that case, the negative terminal is where the 555 00:34:38,520 --> 00:34:42,320 Speaker 1: electrons are and it flows to the positive terminal. Both 556 00:34:42,680 --> 00:34:46,200 Speaker 1: illustrations can describe the exact same circuit, but they're going 557 00:34:46,239 --> 00:34:50,160 Speaker 1: to show a difference in what is positive and negative terminals, 558 00:34:50,480 --> 00:34:54,120 Speaker 1: and so it can get really confusing. Uh. Engineers tend 559 00:34:54,160 --> 00:34:57,120 Speaker 1: to use that conventional flow notation. Professional scientists tend to 560 00:34:57,160 --> 00:35:01,800 Speaker 1: prefer the electron flow notation, and thus we're all left 561 00:35:01,840 --> 00:35:04,840 Speaker 1: scratching our heads. All that being said, an enlightened person 562 00:35:04,920 --> 00:35:08,160 Speaker 1: might argue that Franklin's description is perfectly suitable if we 563 00:35:08,200 --> 00:35:11,320 Speaker 1: look at other examples of electric charge moving across an area, 564 00:35:11,360 --> 00:35:15,360 Speaker 1: Because yes, in wires, we're talking about those negatively charged electrons, 565 00:35:15,360 --> 00:35:19,040 Speaker 1: but in other substances you might talk about protons or 566 00:35:19,200 --> 00:35:23,080 Speaker 1: positively charged ions moving due to a difference in charge. 567 00:35:23,560 --> 00:35:27,520 Speaker 1: And because you have these positively charged ions or even 568 00:35:27,520 --> 00:35:30,520 Speaker 1: sub atomic particles and their movement can also be described 569 00:35:30,560 --> 00:35:35,080 Speaker 1: as electricity. It it's perfectly valid. It's just not what 570 00:35:35,200 --> 00:35:39,080 Speaker 1: we see with electronic circuits. So there's that. Still a 571 00:35:39,080 --> 00:35:41,480 Speaker 1: lot of folks bemoan the fact that Franklin's decision to 572 00:35:41,560 --> 00:35:44,640 Speaker 1: name things as he did was kind of based on 573 00:35:44,680 --> 00:35:47,640 Speaker 1: a whim and it made things more complicated as we 574 00:35:47,760 --> 00:35:50,480 Speaker 1: learned more later on. But honestly, there was no way 575 00:35:50,480 --> 00:35:52,760 Speaker 1: for him to know at the time. It's not really 576 00:35:52,800 --> 00:35:56,960 Speaker 1: his fault. It just kind of turned out that way. Anyway, 577 00:35:57,000 --> 00:35:59,880 Speaker 1: back to the timeline, since we won't learn about electrons 578 00:36:00,080 --> 00:36:03,879 Speaker 1: or a couple of hundred years after Benjamin Franklin's work 579 00:36:03,960 --> 00:36:07,840 Speaker 1: with lightning, we should just go back to what people 580 00:36:07,840 --> 00:36:10,880 Speaker 1: were experimenting with and learning about. So a few decades 581 00:36:10,920 --> 00:36:14,520 Speaker 1: after Franklin's experiments, there was a guy named Charles Augustine 582 00:36:14,600 --> 00:36:18,880 Speaker 1: de Colombe who made some significant contributions to our understanding 583 00:36:18,920 --> 00:36:23,719 Speaker 1: of electricity. He published multiple papers on the subjects of 584 00:36:23,760 --> 00:36:28,160 Speaker 1: electricity and magnetism between seventeen eighty five and seventeen ninety one, 585 00:36:28,200 --> 00:36:30,120 Speaker 1: and he had done a lot of work leading up 586 00:36:30,160 --> 00:36:34,600 Speaker 1: to those publications. Among his discoveries was the relationship between 587 00:36:34,600 --> 00:36:39,239 Speaker 1: the strength of opposite charges and that distance between them. 588 00:36:39,280 --> 00:36:42,520 Speaker 1: He developed what we now call Coulomb's law. Now, this 589 00:36:42,600 --> 00:36:45,840 Speaker 1: law states the electrical or magnetic force depends upon the 590 00:36:45,920 --> 00:36:48,920 Speaker 1: strength and nature of the charges of the two objects 591 00:36:49,400 --> 00:36:52,640 Speaker 1: and the distance between those two objects. So, if you 592 00:36:52,680 --> 00:36:57,360 Speaker 1: have two similarly charged objects, like two positives, they repel 593 00:36:57,480 --> 00:37:02,640 Speaker 1: one another with a non contact force. To opposite charged 594 00:37:02,760 --> 00:37:05,600 Speaker 1: objects a negative and a positive will attract one another 595 00:37:05,920 --> 00:37:10,719 Speaker 1: with a non contact force. These forces are vector quantities, 596 00:37:10,760 --> 00:37:13,600 Speaker 1: which means they have both a magnitude and a direction, 597 00:37:14,040 --> 00:37:16,880 Speaker 1: and the distance between the two objects affects the amount 598 00:37:16,920 --> 00:37:19,560 Speaker 1: of force. The closer the objects are to one another, 599 00:37:19,920 --> 00:37:23,879 Speaker 1: the greater the force is between them, or in other words, 600 00:37:23,920 --> 00:37:27,360 Speaker 1: that the magnitude of the electrosthetic force of attraction between 601 00:37:27,360 --> 00:37:31,319 Speaker 1: two point charges is directly proportional to the product of 602 00:37:31,360 --> 00:37:34,960 Speaker 1: the magnitudes of charges and inversely proportional to the square 603 00:37:35,040 --> 00:37:39,920 Speaker 1: of the distance between them. That's the technical description of 604 00:37:39,960 --> 00:37:42,960 Speaker 1: Coulomb's law. There's also a constant that you have to 605 00:37:43,080 --> 00:37:46,120 Speaker 1: use when you're working with equations using Coulomb's law, but 606 00:37:46,280 --> 00:37:49,520 Speaker 1: we don't need to really dive into that, the point 607 00:37:49,560 --> 00:37:53,960 Speaker 1: being that he realized that distance definitely plays a factor 608 00:37:54,160 --> 00:37:57,160 Speaker 1: with these other forces that we still didn't fully understand 609 00:37:57,200 --> 00:38:02,120 Speaker 1: at that point. Then you have Alessandro Volta, from whom 610 00:38:02,120 --> 00:38:05,320 Speaker 1: we get the word volt He was an Italian physicist 611 00:38:05,400 --> 00:38:08,279 Speaker 1: who became interested in the study of electricity. Now we 612 00:38:08,560 --> 00:38:11,720 Speaker 1: normally credit Volta with the invention of the electric battery, 613 00:38:11,960 --> 00:38:15,560 Speaker 1: those Baghdad batteries set aside. He began by building on 614 00:38:15,600 --> 00:38:19,600 Speaker 1: the work of another physicist named Johann Carl Vilk, who 615 00:38:19,680 --> 00:38:23,640 Speaker 1: had invented the electro forests. The electro forest was a 616 00:38:23,680 --> 00:38:27,160 Speaker 1: simple capacitive generator that could build up an electrostatic charge 617 00:38:27,160 --> 00:38:31,520 Speaker 1: for use and experiments. So all these scientists really wanted 618 00:38:31,560 --> 00:38:33,719 Speaker 1: to study electricity. But to do that you had to 619 00:38:33,719 --> 00:38:37,000 Speaker 1: build up these electrostatic charges so that when you discharge them, 620 00:38:37,040 --> 00:38:39,399 Speaker 1: you had something to study. So this was a guy 621 00:38:39,440 --> 00:38:42,080 Speaker 1: who had developed the electro forests as a way of 622 00:38:42,120 --> 00:38:48,720 Speaker 1: making that easier to do. Um Volta's buddy Luigi Galvani 623 00:38:48,800 --> 00:38:51,920 Speaker 1: had observed something really unusual himself. He noted that when 624 00:38:51,920 --> 00:38:55,160 Speaker 1: he used two different types of metal to make contact 625 00:38:55,160 --> 00:38:58,200 Speaker 1: with the muscle of a frog, an electric current would 626 00:38:58,239 --> 00:39:00,840 Speaker 1: pass between the two, and so he thought the source 627 00:39:00,880 --> 00:39:03,239 Speaker 1: of the electricity was from the frog itself, and he 628 00:39:03,320 --> 00:39:07,440 Speaker 1: called it animal electricity. Volta disagreed, saying that the frog 629 00:39:07,520 --> 00:39:10,480 Speaker 1: was just a conductor, not the generator, and so he 630 00:39:10,520 --> 00:39:14,040 Speaker 1: was calling it metallic electricity. And this was a big 631 00:39:14,080 --> 00:39:19,240 Speaker 1: debate in circles at the time. So in Volta began 632 00:39:19,280 --> 00:39:23,200 Speaker 1: to experiment on metals used, often using his own tongue 633 00:39:23,800 --> 00:39:26,200 Speaker 1: as the laboratory. He would put two different discs of 634 00:39:26,239 --> 00:39:28,279 Speaker 1: metal on his tongue and feel the tingling on his 635 00:39:28,360 --> 00:39:31,839 Speaker 1: tongue and say, yep, there's there's an electric current passing there. 636 00:39:33,239 --> 00:39:34,920 Speaker 1: But he could also use other stuff as well, and 637 00:39:34,960 --> 00:39:37,279 Speaker 1: he was able to observe that in fact, it was 638 00:39:37,320 --> 00:39:41,839 Speaker 1: the metals that were important, not the creature. This also 639 00:39:41,880 --> 00:39:45,080 Speaker 1: inspired Volta to look into electricity further, which culminated with 640 00:39:45,120 --> 00:39:48,399 Speaker 1: the design of the first real battery as far as 641 00:39:48,560 --> 00:39:52,000 Speaker 1: modern science is concerned. It was an eighteen hundred that 642 00:39:52,120 --> 00:39:57,719 Speaker 1: Volta invented the voltaic pile, also known as the voltaic column. 643 00:39:58,120 --> 00:40:01,920 Speaker 1: This battery consisted of alternating layers of zinc and silver, 644 00:40:02,480 --> 00:40:06,360 Speaker 1: or of alternating layers of copper and pewter, with layers 645 00:40:06,400 --> 00:40:09,560 Speaker 1: of paper or cloth soaked in a salt solution in 646 00:40:09,640 --> 00:40:13,319 Speaker 1: between the different metal disks. This arrangement could create a 647 00:40:13,360 --> 00:40:16,760 Speaker 1: steady electric current that didn't need recharging like a Leyden 648 00:40:16,880 --> 00:40:20,280 Speaker 1: jar did, so this was a great solution for engineers 649 00:40:20,280 --> 00:40:23,040 Speaker 1: and scientists who wanted to be able to work with electricity, 650 00:40:23,120 --> 00:40:25,719 Speaker 1: but didn't want to have to stop every time they 651 00:40:25,920 --> 00:40:29,399 Speaker 1: discharged Leyden jar to build up another electrostatic charge. This 652 00:40:29,520 --> 00:40:32,959 Speaker 1: was a a steady source, so it was a huge boon. 653 00:40:33,400 --> 00:40:36,200 Speaker 1: Although he didn't really have any other practical applications for 654 00:40:36,239 --> 00:40:41,800 Speaker 1: electricity just yet. But six weeks after Volta published his findings, 655 00:40:42,320 --> 00:40:47,640 Speaker 1: English scientists William Nicholson and Anthony Carlyle experimented with a 656 00:40:47,719 --> 00:40:51,520 Speaker 1: voltaic pile and electrodes placed in water, and the electric 657 00:40:51,560 --> 00:40:54,279 Speaker 1: current that passed through the water caused the water to 658 00:40:54,400 --> 00:40:59,560 Speaker 1: decompose into hydrogen and oxygen, breaking the molecules of water 659 00:40:59,680 --> 00:41:03,640 Speaker 1: apart art. And this is a process that we call electrolysis, 660 00:41:03,680 --> 00:41:06,520 Speaker 1: specifically with water, but with other things as well, using 661 00:41:06,560 --> 00:41:11,320 Speaker 1: electrical electrical charges to break those molecular bonds. By eighteen 662 00:41:11,360 --> 00:41:16,400 Speaker 1: o two, William Crookshank had designed the first electric battery 663 00:41:16,480 --> 00:41:19,400 Speaker 1: for mass production, using copper and zinc in a wooden 664 00:41:19,480 --> 00:41:23,520 Speaker 1: box filled with an electrolyte of brine and sealed to 665 00:41:23,640 --> 00:41:27,000 Speaker 1: prevent leaking. So a big think of a big wooden 666 00:41:27,080 --> 00:41:30,600 Speaker 1: battery akin to something like a car battery would be 667 00:41:30,719 --> 00:41:34,920 Speaker 1: like this today. So Volta died in eighty seven, and 668 00:41:34,960 --> 00:41:37,800 Speaker 1: it was an eighty one that the scientific community decided 669 00:41:37,840 --> 00:41:42,279 Speaker 1: to name the unit of electromotive force the vault, after him, 670 00:41:42,760 --> 00:41:44,600 Speaker 1: so he was. He did not live to see his 671 00:41:44,719 --> 00:41:49,520 Speaker 1: name used to describe electromotive force, but he certainly was 672 00:41:49,600 --> 00:41:52,919 Speaker 1: the inspiration for it, and other inventors and scientists would 673 00:41:52,960 --> 00:41:56,920 Speaker 1: improve upon Volta's design, including chemist John F. Daniel and 674 00:41:57,040 --> 00:42:01,080 Speaker 1: later a physician from France named Gaston p Ande, who 675 00:42:01,120 --> 00:42:06,080 Speaker 1: designed the first rechargeable lead acid battery. So Plante's design 676 00:42:06,239 --> 00:42:08,920 Speaker 1: is the basis for modern lead acid batteries today, like 677 00:42:08,960 --> 00:42:12,120 Speaker 1: the kind you would find in internal combustion engine vehicles. 678 00:42:12,960 --> 00:42:16,840 Speaker 1: That has its roots back in the early, well early 679 00:42:16,880 --> 00:42:20,920 Speaker 1: to mid nineteenth century. It's kind of incredible. Later on 680 00:42:20,960 --> 00:42:23,360 Speaker 1: you would see other improvements with battery technology. Might as 681 00:42:23,400 --> 00:42:25,920 Speaker 1: well stick with that for right now. That would include 682 00:42:25,960 --> 00:42:29,360 Speaker 1: the nickel cadmium battery, which was first designed by Valdemar 683 00:42:29,520 --> 00:42:34,320 Speaker 1: Jongner from Sweden in eight and the nickel iron battery 684 00:42:34,680 --> 00:42:39,000 Speaker 1: designed by Thomas Edison, or at least Thomas Edison's team 685 00:42:39,080 --> 00:42:43,640 Speaker 1: of engineers and scientists. There's always a caveat whenever you 686 00:42:43,680 --> 00:42:46,680 Speaker 1: say Thomas Edison's invention, because he had a whole lot 687 00:42:46,680 --> 00:42:50,000 Speaker 1: of people working for him who were busy research in 688 00:42:50,719 --> 00:42:54,399 Speaker 1: developing all sorts of different technologies, and Edison's name gets 689 00:42:54,440 --> 00:42:56,600 Speaker 1: attached to a lot of it. Edison himself was a 690 00:42:56,600 --> 00:43:01,120 Speaker 1: brilliant guy, uh but he larged. He was brilliant in 691 00:43:01,360 --> 00:43:05,600 Speaker 1: bringing people to work on these cool ideas, um sometimes 692 00:43:05,680 --> 00:43:08,920 Speaker 1: contributing to him directly. Sometimes he wasn't, but he was 693 00:43:09,120 --> 00:43:13,920 Speaker 1: providing the space for that kind of work to happen anyway. 694 00:43:14,560 --> 00:43:17,880 Speaker 1: He helped develop the first nickel iron battery in nineteen 695 00:43:17,960 --> 00:43:21,360 Speaker 1: o one. But I've talked a lot about batteries, so 696 00:43:21,680 --> 00:43:24,320 Speaker 1: what I'll do in the next section is talk about 697 00:43:24,360 --> 00:43:27,359 Speaker 1: other developments in electricity. But before I jump into that, 698 00:43:27,680 --> 00:43:37,279 Speaker 1: let's take another quick break to thank our sponsor. So 699 00:43:37,520 --> 00:43:43,759 Speaker 1: one of Volta's contemporaries was Andre Marie Ampere. We talked 700 00:43:43,800 --> 00:43:48,600 Speaker 1: about amps and amperage. It comes from Ampaire, so his 701 00:43:48,719 --> 00:43:52,640 Speaker 1: name also serves as a type of scientific unit, basically 702 00:43:52,719 --> 00:43:57,120 Speaker 1: one describing current as opposed to voltage. And Pierre noted 703 00:43:57,160 --> 00:43:59,880 Speaker 1: in eighteen twenty that a wire carrying an electric cur 704 00:44:00,280 --> 00:44:03,440 Speaker 1: was sometimes attracted to and other times repelled by other 705 00:44:03,520 --> 00:44:07,360 Speaker 1: such wires. So he was starting to notice this magnetic 706 00:44:07,400 --> 00:44:13,080 Speaker 1: attraction along current carrying wires, and in eighteen thirty one, 707 00:44:13,120 --> 00:44:17,040 Speaker 1: another fellow, Michael Faraday, explored this idea further, and he 708 00:44:17,120 --> 00:44:21,560 Speaker 1: discovered that if he revolved a copper disc inside a 709 00:44:21,680 --> 00:44:26,279 Speaker 1: strong magnetic field, it would generate an electric current inside 710 00:44:26,360 --> 00:44:30,040 Speaker 1: the copper disk. Faraday and a guy named Humphrey Davy 711 00:44:30,120 --> 00:44:34,080 Speaker 1: would later build an early electric generator using this discovery. 712 00:44:34,120 --> 00:44:37,240 Speaker 1: The generator consisted of a coil of copper that would 713 00:44:37,239 --> 00:44:40,920 Speaker 1: be moved past a magnet. And this is the very 714 00:44:41,239 --> 00:44:45,640 Speaker 1: very rough basic idea for electric generators today. Moving a 715 00:44:45,640 --> 00:44:48,920 Speaker 1: conductor through a magnetic field induces electricity to flow through 716 00:44:48,920 --> 00:44:53,200 Speaker 1: the conductor. That's the simplified version. Now more specifically, the 717 00:44:53,280 --> 00:44:57,480 Speaker 1: greatest current flows through a conductor when the conductor is 718 00:44:57,520 --> 00:45:01,239 Speaker 1: moving through the most lines of magnetic flux at it 719 00:45:01,360 --> 00:45:06,200 Speaker 1: the fastest rate. So magnetic flux is a magnetic field 720 00:45:06,280 --> 00:45:11,320 Speaker 1: passing through a surface. You've probably seen illustrations of magnetic fields. 721 00:45:11,920 --> 00:45:15,319 Speaker 1: Imagine a bar magnet. It's just a simple rectangle. You 722 00:45:15,360 --> 00:45:17,719 Speaker 1: have a north pole of the bar magnet and a 723 00:45:17,719 --> 00:45:20,840 Speaker 1: south pole of the bar magnet. You would draw lines 724 00:45:20,880 --> 00:45:25,399 Speaker 1: extending outward from the north pole. These lines would start 725 00:45:25,400 --> 00:45:29,560 Speaker 1: to loop back down towards the south pole in ever 726 00:45:29,680 --> 00:45:34,800 Speaker 1: increasing but less strong uh magnetic lines that go further 727 00:45:34,880 --> 00:45:37,560 Speaker 1: out until you get a couple that don't even loop 728 00:45:37,600 --> 00:45:39,720 Speaker 1: back down to the south pole. They just go outward. 729 00:45:40,840 --> 00:45:44,200 Speaker 1: So lines extend out from the north pole and go 730 00:45:44,400 --> 00:45:47,839 Speaker 1: into the south pole, and you designate this by drawing 731 00:45:47,920 --> 00:45:52,000 Speaker 1: little arrows on the lines to show the direction of this. 732 00:45:52,160 --> 00:45:57,640 Speaker 1: The vector quality of this at the south pole you've 733 00:45:57,680 --> 00:46:00,360 Speaker 1: got all those incoming lines, including a couple from apparently 734 00:46:00,440 --> 00:46:04,800 Speaker 1: external sources. When you look at the illustrations of magnetic fields, 735 00:46:04,800 --> 00:46:08,240 Speaker 1: so if you move a conductor through these magnetic fields, 736 00:46:08,280 --> 00:46:11,760 Speaker 1: it sort of breaks those lines. It moves through those 737 00:46:11,800 --> 00:46:16,120 Speaker 1: those lines of magnetic force um and you do it quickly, 738 00:46:16,719 --> 00:46:20,440 Speaker 1: current will flow through the conductor. It induces current to flow, 739 00:46:21,480 --> 00:46:24,600 Speaker 1: and the most current will flow when the conductor moves 740 00:46:24,640 --> 00:46:28,319 Speaker 1: through the ninety degree perpendicular plane with respect to the 741 00:46:28,360 --> 00:46:32,560 Speaker 1: magnetic field. So again, if you've got let's imagine that 742 00:46:32,560 --> 00:46:36,680 Speaker 1: the conductor is a a square. We've got a square 743 00:46:36,680 --> 00:46:39,960 Speaker 1: of copper. It's it's not solid copper. It's just a 744 00:46:40,840 --> 00:46:43,920 Speaker 1: copper wire that's been shaped in the form of a square. 745 00:46:44,440 --> 00:46:46,560 Speaker 1: It's got two prongs at the base of it that 746 00:46:46,680 --> 00:46:49,719 Speaker 1: go down to where there's a crank. So I can 747 00:46:49,760 --> 00:46:53,440 Speaker 1: turn the crank and this will rotate the square. Right now, 748 00:46:53,480 --> 00:46:56,080 Speaker 1: let's say to either side of the square, I put 749 00:46:56,120 --> 00:46:59,800 Speaker 1: two very powerful magnets. One of them has the north 750 00:47:00,000 --> 00:47:03,520 Speaker 1: goal facing into the gap. The other one has its 751 00:47:03,680 --> 00:47:07,000 Speaker 1: south pole facing into the gap. The squares in the 752 00:47:07,080 --> 00:47:11,360 Speaker 1: center in between these two magnets. When I turned the 753 00:47:11,360 --> 00:47:15,920 Speaker 1: square so that it is perpendicular to the magnetic field 754 00:47:16,080 --> 00:47:20,080 Speaker 1: extending out from these magnets. That is the moment when 755 00:47:20,080 --> 00:47:22,640 Speaker 1: it's going to have the most current flowing through the 756 00:47:22,640 --> 00:47:25,040 Speaker 1: square as it as it moves. It has to be 757 00:47:25,120 --> 00:47:29,000 Speaker 1: moving for this to really work. When you get it 758 00:47:29,080 --> 00:47:33,720 Speaker 1: parallel with the magnetic fields, you will have the least 759 00:47:33,880 --> 00:47:36,920 Speaker 1: amount of current. In fact, you have no current at 760 00:47:36,960 --> 00:47:40,200 Speaker 1: all flowing through it at that moment. If you keep 761 00:47:40,280 --> 00:47:43,560 Speaker 1: it turning, then you will be able to generate current 762 00:47:44,440 --> 00:47:50,480 Speaker 1: h fairly consistently. It does actually pulse, it's not it's 763 00:47:50,520 --> 00:47:52,920 Speaker 1: not steady. If you were to measure it out, you 764 00:47:52,920 --> 00:47:54,960 Speaker 1: would actually see it pulsing. And only does it pulse, 765 00:47:55,719 --> 00:48:01,040 Speaker 1: the direction of current will change. Uh, so it's actually 766 00:48:01,160 --> 00:48:04,880 Speaker 1: alternating current. But we'll talk about that again in a 767 00:48:04,920 --> 00:48:07,560 Speaker 1: little bit more a little bit later to really get 768 00:48:07,600 --> 00:48:10,920 Speaker 1: into alternating current. Because in eighteen thirty two there was 769 00:48:10,960 --> 00:48:15,719 Speaker 1: a French inventor named Pixie p I x I I M. 770 00:48:16,080 --> 00:48:22,360 Speaker 1: Hippolyte Pixie or Hippolyta if you prefer, But he built 771 00:48:22,360 --> 00:48:25,640 Speaker 1: an electrical generator based off of Faraday's discoveries that was 772 00:48:25,719 --> 00:48:28,480 Speaker 1: very similar to what I just described. Had these permanent 773 00:48:28,520 --> 00:48:32,600 Speaker 1: magnets that had a rotating conductor, that would um actually 774 00:48:32,680 --> 00:48:35,120 Speaker 1: really had a spinning magnet and a steady conductor. But 775 00:48:35,239 --> 00:48:39,040 Speaker 1: same same principle. Right, you've got a spinning magnet and 776 00:48:39,080 --> 00:48:42,400 Speaker 1: a steady conductor. You could rearrange that as a spinning 777 00:48:42,400 --> 00:48:46,640 Speaker 1: conductor in a steady magnet. Doesn't really matter. He found 778 00:48:46,640 --> 00:48:49,480 Speaker 1: that the current direction changed each time the north pole 779 00:48:49,520 --> 00:48:52,400 Speaker 1: passed over the coil after the south pole had passed 780 00:48:52,400 --> 00:48:55,840 Speaker 1: over the coil. And this was an early alternating current generator, 781 00:48:55,960 --> 00:48:59,120 Speaker 1: but there was no real use for alternating current at 782 00:48:59,120 --> 00:49:02,440 Speaker 1: that time, so and Here advised Pixie to design a 783 00:49:02,520 --> 00:49:06,960 Speaker 1: generator with a device known as a commutator. Commutators are 784 00:49:07,000 --> 00:49:11,400 Speaker 1: meant to change alternating current to direct current. So the 785 00:49:11,400 --> 00:49:15,080 Speaker 1: difference between alternating current and direct current is alternating current 786 00:49:15,280 --> 00:49:19,600 Speaker 1: changes the direction of the current. So you have electrons 787 00:49:19,640 --> 00:49:23,160 Speaker 1: flowing through a circuit in one direction, and then they 788 00:49:23,160 --> 00:49:28,280 Speaker 1: will reverse and flow into the other direction with alternating current, 789 00:49:28,520 --> 00:49:33,600 Speaker 1: and they do this many times every second. Then you 790 00:49:33,719 --> 00:49:37,280 Speaker 1: have direct current, where the direction of flow is always 791 00:49:37,320 --> 00:49:41,040 Speaker 1: the same. It goes from if you're doing the conventional 792 00:49:41,080 --> 00:49:43,880 Speaker 1: flow diagram, it goes from the positive terminal to the 793 00:49:43,920 --> 00:49:48,000 Speaker 1: negative terminal and it's never gonna change. It's always gonna 794 00:49:48,000 --> 00:49:51,719 Speaker 1: follow that batteries give off direct current. Power plants that 795 00:49:51,840 --> 00:49:54,040 Speaker 1: use a C generators give off a C current. And 796 00:49:54,040 --> 00:49:57,000 Speaker 1: I'll talk more about that in part two. But why 797 00:49:57,040 --> 00:50:00,160 Speaker 1: do generators create alternating current? And how do commutators work? Well, 798 00:50:00,200 --> 00:50:03,239 Speaker 1: remember that example I just gave. You've got this square 799 00:50:03,400 --> 00:50:09,320 Speaker 1: rotating conductor copper wire. It's in between the two magnets. Uh. 800 00:50:09,480 --> 00:50:12,440 Speaker 1: Let's say that you've got your square position between the 801 00:50:12,440 --> 00:50:14,160 Speaker 1: south pole of one magnet the north pole of the 802 00:50:14,239 --> 00:50:16,640 Speaker 1: other magnet. And at the moment you're holding the square 803 00:50:16,640 --> 00:50:20,120 Speaker 1: steady between the two magnets, and you put put a 804 00:50:20,160 --> 00:50:23,760 Speaker 1: piece of blue tape on the side that's facing magnet 805 00:50:23,920 --> 00:50:26,600 Speaker 1: number one, which has the south pole facing into the gap, 806 00:50:26,960 --> 00:50:29,480 Speaker 1: and you put a piece of red tape on the 807 00:50:29,640 --> 00:50:32,719 Speaker 1: side facing magnet two, which is the north pole of 808 00:50:32,760 --> 00:50:35,279 Speaker 1: the other magnet. And then you rotate the square so 809 00:50:35,320 --> 00:50:40,239 Speaker 1: that it moves down or back with respect to magnet one, 810 00:50:40,320 --> 00:50:43,960 Speaker 1: and up or forward with respect to magnet two. So 811 00:50:44,160 --> 00:50:46,520 Speaker 1: if you're staring at this, you see that blue tape 812 00:50:46,520 --> 00:50:50,440 Speaker 1: start to move down. Let's say that we've got this 813 00:50:50,800 --> 00:50:56,040 Speaker 1: horizontally aligned. It appears to move down with respect to 814 00:50:56,080 --> 00:50:58,960 Speaker 1: the magnets. The red tape moves up with respect to 815 00:50:59,000 --> 00:51:01,759 Speaker 1: the magnets, and as it does, this induces current to 816 00:51:01,800 --> 00:51:04,760 Speaker 1: flow in one direction in the copper wire. But once 817 00:51:04,840 --> 00:51:08,520 Speaker 1: the square hits that parallel position with the magnetic fields 818 00:51:09,280 --> 00:51:12,600 Speaker 1: and then continues its turn, the side that was going 819 00:51:12,680 --> 00:51:15,200 Speaker 1: up is now going down through a magnetic field, and 820 00:51:15,239 --> 00:51:17,319 Speaker 1: the side that was going down through a magnetic field 821 00:51:17,360 --> 00:51:19,840 Speaker 1: is now going up through a magnetic field. So the 822 00:51:19,840 --> 00:51:22,879 Speaker 1: red tape takes this turn starts moving downward. The red 823 00:51:22,920 --> 00:51:25,120 Speaker 1: blue tape is making its turn and moving upward, and 824 00:51:25,200 --> 00:51:28,320 Speaker 1: at that moment, when the conductor breaks that parallel plane, 825 00:51:29,160 --> 00:51:33,520 Speaker 1: the current reverses direction. Turning the conductor quickly will induce 826 00:51:33,560 --> 00:51:36,600 Speaker 1: more current to flow and increase the number of cycles 827 00:51:36,640 --> 00:51:40,960 Speaker 1: the current flow reverses per given unit of time. Now, 828 00:51:41,000 --> 00:51:43,600 Speaker 1: as I said, this is alternating current, but the early 829 00:51:43,640 --> 00:51:46,640 Speaker 1: experiments for the day, they really needed direct current, not 830 00:51:46,760 --> 00:51:49,040 Speaker 1: alternating current, which means you have to find a way 831 00:51:49,040 --> 00:51:51,800 Speaker 1: to make the current flow stable in a single direction, 832 00:51:52,120 --> 00:51:55,560 Speaker 1: and that's where a commutator comes in. A simple commutator 833 00:51:55,680 --> 00:51:59,000 Speaker 1: is a split ring where the two sides of the 834 00:51:59,080 --> 00:52:02,319 Speaker 1: ring are made up of conductive material, but they're insulated 835 00:52:02,400 --> 00:52:06,800 Speaker 1: from each other with an insulating material in between them. 836 00:52:06,880 --> 00:52:11,040 Speaker 1: So imagine a ring that has one tiny sliver cut 837 00:52:11,040 --> 00:52:13,840 Speaker 1: out of the ring, so it's like two halves of 838 00:52:13,880 --> 00:52:16,840 Speaker 1: a ring, and then you have an insulator in between 839 00:52:16,880 --> 00:52:21,799 Speaker 1: the two halves. On either side of this uh split ring, 840 00:52:22,280 --> 00:52:26,000 Speaker 1: you have elements that we call brushes. These are just 841 00:52:26,360 --> 00:52:31,439 Speaker 1: conductive materials that are stationary contacts. They make contact with 842 00:52:31,520 --> 00:52:36,400 Speaker 1: this rotating split ring. So as the conductor turns, so 843 00:52:36,520 --> 00:52:38,840 Speaker 1: does the split ring. And while the direction of current 844 00:52:38,960 --> 00:52:42,080 Speaker 1: changes within the conductor, the nature of the split ring 845 00:52:42,160 --> 00:52:45,600 Speaker 1: makes the flow of current and the overall circuit unidirectional. 846 00:52:46,200 --> 00:52:48,879 Speaker 1: Now I realized this is really difficult to visualize without help, 847 00:52:48,960 --> 00:52:51,880 Speaker 1: so I actually recommend that you go look up videos 848 00:52:51,920 --> 00:52:55,600 Speaker 1: about d C generators to get a better idea of 849 00:52:55,640 --> 00:52:59,040 Speaker 1: what I'm talking about. Because a DC generator, and it's 850 00:52:59,200 --> 00:53:02,680 Speaker 1: most basic level, is really an a C generator with 851 00:53:02,719 --> 00:53:06,440 Speaker 1: a commutator attached to it. The important thing note is 852 00:53:06,480 --> 00:53:09,680 Speaker 1: that the basic generator makes al dre and current and 853 00:53:09,719 --> 00:53:13,880 Speaker 1: the commutator makes it into direct current. Now, at this stage, 854 00:53:13,920 --> 00:53:17,799 Speaker 1: electricity was still something scientists and engineers would experiment with 855 00:53:18,040 --> 00:53:21,200 Speaker 1: they still didn't have any real practical uses for electricity 856 00:53:21,320 --> 00:53:23,399 Speaker 1: right now, not on a massive scale at any rate. 857 00:53:24,160 --> 00:53:27,280 Speaker 1: But over the course of the nineteenth century, it became 858 00:53:27,320 --> 00:53:31,520 Speaker 1: clear that electricity had the potential. It's another electricity pun 859 00:53:31,600 --> 00:53:34,800 Speaker 1: for you to change the world. So in our next episode, 860 00:53:35,040 --> 00:53:37,960 Speaker 1: we're gonna look at the discovery of the actual electron, 861 00:53:38,160 --> 00:53:40,959 Speaker 1: which happened at the very tail end of the nineteenth century. 862 00:53:41,040 --> 00:53:44,200 Speaker 1: We'll talk about the atomic physics involved in electricity. We'll 863 00:53:44,239 --> 00:53:47,399 Speaker 1: also talk about d C versus a C as far 864 00:53:47,440 --> 00:53:51,240 Speaker 1: as the current wars were concerned, and Edison versus Tesla 865 00:53:51,560 --> 00:53:55,480 Speaker 1: and why Edison versus Tesla is really an oversimplification of 866 00:53:55,560 --> 00:53:59,080 Speaker 1: that actual battle. And we'll talk about the rise of 867 00:53:59,080 --> 00:54:01,440 Speaker 1: power grids and the various methods that we use to 868 00:54:01,640 --> 00:54:06,160 Speaker 1: actually generate electricity, from coal plants to nuclear reactors. In 869 00:54:06,200 --> 00:54:08,680 Speaker 1: the meantime, if you guys have any suggestions for future 870 00:54:08,680 --> 00:54:11,120 Speaker 1: episodes of tech Stuff, I recommend you get in touch 871 00:54:11,160 --> 00:54:15,319 Speaker 1: with me. My email address is text stuff at how 872 00:54:15,400 --> 00:54:17,840 Speaker 1: stuff Works dot com, or you can drop me a 873 00:54:17,880 --> 00:54:21,120 Speaker 1: line on Twitter or Facebook. The handle for the show 874 00:54:21,120 --> 00:54:24,040 Speaker 1: at both of those is text Stuff H s W. 875 00:54:24,920 --> 00:54:27,879 Speaker 1: As always, I'm happy to hear any suggestions you might have, 876 00:54:27,920 --> 00:54:30,200 Speaker 1: whether it's a topic for a show or a guest 877 00:54:30,239 --> 00:54:32,279 Speaker 1: I should have on the show, Get in touch with 878 00:54:32,280 --> 00:54:34,800 Speaker 1: me and let me know. Also, remember you can watch 879 00:54:34,840 --> 00:54:38,960 Speaker 1: me record these things live on Twitch. Just go to 880 00:54:39,040 --> 00:54:42,000 Speaker 1: twitch dot tv slash tech stuff to see the schedule. 881 00:54:42,640 --> 00:54:44,560 Speaker 1: And I hope I will see you guys in there 882 00:54:44,600 --> 00:54:46,640 Speaker 1: because it's a fun time and you get to talk 883 00:54:46,680 --> 00:54:50,800 Speaker 1: to me a lot while I record these things. And meanwhile, 884 00:54:51,000 --> 00:54:59,719 Speaker 1: I'll talk to you guys again really soon. For more 885 00:54:59,719 --> 00:55:02,040 Speaker 1: on us and thousands of other topics is at how 886 00:55:02,120 --> 00:55:12,840 Speaker 1: stuff works dot com.