WEBVTT - The Birth of Magnavox 0:00:04.400 --> 0:00:07.800 Welcome to tech Stuff, a production from I Heart Radio. 0:00:12.119 --> 0:00:15.160 Hey there, and welcome to tech Stuff. I'm your host, 0:00:15.320 --> 0:00:18.840 Jonathan Strickland. I'm an executive producer with I Heart Radio 0:00:19.000 --> 0:00:23.320 and I love all things tech and recently I covered 0:00:23.360 --> 0:00:26.920 the video game crash of Night three, and in that 0:00:27.000 --> 0:00:30.560 episode I also talked about an earlier video game market 0:00:30.600 --> 0:00:34.760 crash that happened in nine Now I also talked about 0:00:34.760 --> 0:00:39.960 a company called Magnavox and the Magnavox Odyssey console that 0:00:40.200 --> 0:00:44.080 ushered in the early era of home video game systems. Well, today, 0:00:44.120 --> 0:00:47.640 I thought we would learn more about the company Magnavox, 0:00:47.800 --> 0:00:50.880 where it came from, and how it played an important 0:00:51.000 --> 0:00:55.120 part in the history of electronics, because, as it turns out, 0:00:55.200 --> 0:01:00.560 Magnavox has a really interesting history beyond the fact that 0:01:00.640 --> 0:01:06.040 it helped bring about the the age of home video games. 0:01:06.120 --> 0:01:08.840 So this is gonna be a deep dive series into 0:01:08.880 --> 0:01:13.400 the history of Magnavox. And like most of my history series, 0:01:13.520 --> 0:01:16.960 I like to take opportunities to talk about certain technologies 0:01:17.280 --> 0:01:20.720 that played an important role in the company's history and 0:01:20.800 --> 0:01:23.640 explain how those technologies work. It's kind of my sneaky 0:01:23.720 --> 0:01:27.039 way of talking about how tech works. So there's gonna 0:01:27.040 --> 0:01:30.800 be a lot of that in these episodes because the 0:01:30.840 --> 0:01:35.160 founding of Magnavox itself actually comes from a pivotal technology 0:01:35.200 --> 0:01:37.679 in the history of radio. So we're gonna be talking 0:01:38.120 --> 0:01:41.479 a lot about radio early on in this episode in particular. 0:01:41.560 --> 0:01:45.400 So while I'm calling this the history of Magnavox, you're 0:01:45.440 --> 0:01:48.200 getting a ton of extra content on top of that. 0:01:48.920 --> 0:01:52.120 You're welcome. Now, it also means that we're gonna have 0:01:52.160 --> 0:01:56.520 to learn about the history of the co founders of Magnavox, 0:01:57.160 --> 0:02:00.920 and we usually say that the founders were uh, Peter 0:02:01.280 --> 0:02:06.400 Jensen from Denmark and Edward Pridom. Now we'll start with 0:02:06.440 --> 0:02:10.639 Pridum because I actually know the least about him. There 0:02:10.639 --> 0:02:13.160 are more sources to have at least something to say 0:02:13.160 --> 0:02:17.320 about Jensen. He's he's something of a hero in Denmark, 0:02:18.040 --> 0:02:20.800 and I'm not sure what caused the disparity here where 0:02:21.080 --> 0:02:24.880 Jensen has way more about him than Pridom does. But 0:02:24.919 --> 0:02:27.040 I'll give you what I do know about pried Um. 0:02:27.040 --> 0:02:32.079 So unfortunate in that there are historians who focused primarily 0:02:32.280 --> 0:02:36.080 on hyper local history, like the history of a specific town, 0:02:36.200 --> 0:02:39.600 for example, and I happened to come across one that 0:02:39.760 --> 0:02:45.080 incidentally had information about Edwin Priddham. His father, James, was 0:02:45.200 --> 0:02:49.880 born in eighteen forty four, so before the Civil War 0:02:49.919 --> 0:02:52.840 in the United States, but James was born in Quebec, Canada. 0:02:53.160 --> 0:02:57.840 He immigrated to Joaukegan, Illinois, in eighteen seventy one. There 0:02:57.880 --> 0:03:02.560 he met a woman named Jeannette Lagrange McClaskey, and the 0:03:02.600 --> 0:03:05.400 two fell in love and they got married in eighteen 0:03:05.440 --> 0:03:11.760 seventy three. James Priddom's occupation was that of a manufacturing 0:03:12.080 --> 0:03:15.720 chemist or a druggist, and he would end up running 0:03:15.760 --> 0:03:19.799 a drug store in Woaukegan for several years, and from 0:03:19.800 --> 0:03:21.560 what I can tell, he appeared to be a pretty 0:03:21.600 --> 0:03:25.920 successful businessman. He and his wife moved to Maywood, Illinois 0:03:26.280 --> 0:03:30.320 in eighteen seventy eight, and in eighteen eighty one they 0:03:30.360 --> 0:03:34.440 welcomed their son, Edwin S. Priddom, to the world. I 0:03:34.520 --> 0:03:39.560 don't have much other information about Edwin's upbringing. I do 0:03:39.720 --> 0:03:43.640 know he attended Stanford University and he graduated in nineteen 0:03:43.640 --> 0:03:47.440 o nine with a degree in physics. After graduation, he 0:03:47.600 --> 0:03:52.720 joined fellow Stanford graduate Cyril Frank Lwell. Now l Will 0:03:52.760 --> 0:03:55.480 had actually graduated a couple of years previously in nineteen 0:03:55.480 --> 0:03:58.760 o seven, and l Will was trying to produce a 0:03:58.840 --> 0:04:02.160 system that would allow for the wireless transmission of voice 0:04:02.160 --> 0:04:07.800 communication aka you know, radio voice transmissions. This was in 0:04:07.840 --> 0:04:12.040 Palo Alto, California. And we'll leave Pritam there for now, 0:04:12.280 --> 0:04:16.800 and we will rejoin him momentarily. But now, whether Jensen 0:04:17.520 --> 0:04:24.240 so Peter Jensen was born in eighteen eighty six, and uh, 0:04:24.360 --> 0:04:27.000 he was born on the island Foster, which is part 0:04:27.040 --> 0:04:31.359 of Denmark. As for where he attended school, by that, 0:04:31.480 --> 0:04:36.000 I am somewhat baffled because at least according to Wikipedia, 0:04:36.240 --> 0:04:39.200 and bear with me, we'll touch on this, but according 0:04:39.240 --> 0:04:43.200 to Wikipedia, he went to Amherst College. Amherst College is 0:04:43.200 --> 0:04:47.000 in Massachusetts in the United States, and according to Wikipedia, 0:04:47.200 --> 0:04:50.359 he graduated from this college with a degree in liberal 0:04:50.600 --> 0:04:55.120 arts in nineteen o six. Now, immediately, that didn't sound 0:04:55.200 --> 0:04:57.840 right to me, and I tried to verify this. And 0:04:58.440 --> 0:05:03.000 because that particular fact in the wiki page had no citation, right, 0:05:03.000 --> 0:05:07.080 there was no source connected to this claim, and it 0:05:07.240 --> 0:05:09.760 sounded like it was off to me. So I did 0:05:09.839 --> 0:05:13.480 some searches to find out whether or not this was accurate. 0:05:13.520 --> 0:05:16.200 I found a couple of other sources that also mentioned Amherst, 0:05:16.480 --> 0:05:20.240 but every single one of them, including the Wikipedia page, 0:05:20.560 --> 0:05:26.200 used the exact same wording, so clearly these are all 0:05:26.279 --> 0:05:28.479 copies of each other. I don't know which one is 0:05:28.520 --> 0:05:31.280 the original. Maybe it's the Wikipedia page, maybe it's one 0:05:31.279 --> 0:05:34.240 of the others, but they all used exactly the same words, 0:05:34.400 --> 0:05:38.520 not like they were rephrasing things. So my guess was 0:05:38.560 --> 0:05:40.839 that this was a mistake that happened in one place, 0:05:41.279 --> 0:05:44.680 and then lots of other people copied it. And again, 0:05:44.720 --> 0:05:46.960 the reason I find this all baffling is that, according 0:05:47.000 --> 0:05:51.520 to most other sources, the young Jensen found himself apprenticed 0:05:51.640 --> 0:05:56.520 to Dutch inventor Valdemar Poulson in nineteen o three, So 0:05:57.240 --> 0:06:01.920 even the Wikipedia article says this that he joined Paulson 0:06:02.040 --> 0:06:05.760 as an apprentice in nineteen o three. Paulson, however, lived 0:06:05.839 --> 0:06:09.800 and worked in Denmark, so that raises the question how 0:06:09.839 --> 0:06:12.720 the heck would a young Jenson be able to travel 0:06:12.800 --> 0:06:15.880 all the way to the United States and attend Amherst 0:06:16.080 --> 0:06:19.000 while also working for Paulson, because the two would have 0:06:19.040 --> 0:06:21.440 had to happen at the same time. So I'm pretty 0:06:21.440 --> 0:06:24.120 sure that has to be an error and a reminder 0:06:24.520 --> 0:06:27.320 that if you go to Wikipedia, it's a great place 0:06:27.360 --> 0:06:30.279 to look for initial sources. It is not always the 0:06:30.320 --> 0:06:34.240 most reliable resource in of itself. I mean it's it's 0:06:34.279 --> 0:06:38.000 not usually this bad, but this is pretty bad. Anyway, 0:06:38.240 --> 0:06:41.479 I'm going to assume that Jensen didn't leave Denmark before 0:06:41.560 --> 0:06:45.040 nineteen o nine or so, particularly since at least some 0:06:45.160 --> 0:06:49.359 sources suggest it would be his future business partner Pritum 0:06:49.400 --> 0:06:53.520 who would help Jensen learn English. Surely, if he had 0:06:53.560 --> 0:06:57.200 attended Amherst in the United States and received a Liberal 0:06:57.320 --> 0:06:59.880 Arts degree of all things, he would have to have 0:07:00.040 --> 0:07:04.320 been pretty fluent in English before leaving in nineteen o nine, 0:07:04.880 --> 0:07:11.400 But will let that sit for now. Baltimore Poulson, Jensen's mentor, 0:07:12.040 --> 0:07:15.920 was an inventor who made significant contributions to fields like 0:07:16.080 --> 0:07:20.680 radio communication and magnetic recording. If you've listened to other 0:07:20.720 --> 0:07:23.560 Tech Stuff episodes, you've heard me talk about that kind 0:07:23.560 --> 0:07:26.240 of stuff before. We will touch on a few things 0:07:26.240 --> 0:07:29.080 throughout this episode in order to understand their significance as 0:07:29.120 --> 0:07:32.760 well as you know how they actually worked. Anyway, Jensen 0:07:32.840 --> 0:07:36.560 worked with Poulson, gaining valuable experience and knowledge in the 0:07:36.600 --> 0:07:40.680 field of radio physics and electronics. One invention in particular 0:07:40.920 --> 0:07:44.240 would become instrumental for our stories beginning, and that would 0:07:44.240 --> 0:07:48.280 be the arc radio transmitter. But all of this requires 0:07:48.360 --> 0:07:51.960 multiple explanations so that we can understand why it's important. 0:07:52.280 --> 0:07:56.520 So in the very early days of radio transmissions, engineers 0:07:56.560 --> 0:08:01.200 worked with something called spark transmitters, and this stuff ends 0:08:01.280 --> 0:08:04.120 up being really important because it does lead eventually to 0:08:04.200 --> 0:08:06.720 Jansen and print a meeting. So we're gonna take a 0:08:06.760 --> 0:08:08.760 trip down this rabbit hole to learn about the early 0:08:08.840 --> 0:08:12.280 days of radio. And by early I mean when folks 0:08:12.320 --> 0:08:15.480 first started discovering that this was a thing that we 0:08:15.560 --> 0:08:20.000 could create and detect radio waves. So in order to 0:08:20.040 --> 0:08:22.840 get that basic understanding, like this just becomes an onion, 0:08:22.880 --> 0:08:25.120 I get it, but you know, we have to have 0:08:25.160 --> 0:08:29.240 this basis of understanding. We're gonna start with James Clerk Maxwell. Now, 0:08:29.280 --> 0:08:32.040 you could technically go back earlier, but I'm not going 0:08:32.120 --> 0:08:35.079 to do that. So in the mid nineteenth century, Maxwell 0:08:35.200 --> 0:08:37.880 was looking at the work done by folks like Charles 0:08:37.880 --> 0:08:45.120 Augustine de Colombe, Michael Faraday, Andre Marie Empire, Franz Ernst Neuman, 0:08:45.360 --> 0:08:49.480 and Emile Lens. So see, like you could go further 0:08:49.559 --> 0:08:51.880 back but that would be an entire episode by itself. 0:08:51.920 --> 0:08:54.520 Maybe one day I will to just talk about the 0:08:54.559 --> 0:08:58.840 steps that led to us understanding and then leveraging things 0:08:58.840 --> 0:09:01.960 like radio waves. Any Maxwell was trying to suss out 0:09:02.080 --> 0:09:06.200 the math that would help explain the various observations that 0:09:06.280 --> 0:09:09.720 had been made by these earlier scientists, and most of 0:09:09.720 --> 0:09:13.880 those observations dealt with our growing understanding of electricity and 0:09:14.000 --> 0:09:17.280 magnetism and how those two things relate to one another, 0:09:17.320 --> 0:09:21.640 in other words, electromagnetism. So Maxwell developed a series of 0:09:21.640 --> 0:09:26.400 equations to describe the relationships between electricity and magnetism, and 0:09:26.440 --> 0:09:29.840 this became the foundation for our understanding of electromagnetism, and 0:09:29.880 --> 0:09:34.600 it also ended up creating certain predictions that Maxwell himself 0:09:34.640 --> 0:09:38.600 had no way of testing. There are entire college courses 0:09:38.640 --> 0:09:41.840 dedicated to Maxwell's equations, and there's no way I could 0:09:41.880 --> 0:09:45.040 do that subject matter justice in this episode. So what's 0:09:45.080 --> 0:09:48.360 important for us to realize is that another smarty pants 0:09:48.559 --> 0:09:51.400 by the name of Heinrich Hurtz. I'm sure that last 0:09:51.480 --> 0:09:55.760 name sounds familiar. He was able to create scientific experiments 0:09:56.000 --> 0:09:59.840 to look for something that Maxwell's equations had predicted. So 0:09:59.880 --> 0:10:04.080 he was actually putting these predictions to the test. Maxwell 0:10:04.160 --> 0:10:09.280 predicted the existence of electromagnetic waves. But that you know, 0:10:09.320 --> 0:10:11.280 that's a great prediction, But how would you know if 0:10:11.320 --> 0:10:13.400 you if you were around them. I mean, they are 0:10:13.440 --> 0:10:17.640 invisible apart from light, which is part of the electromagnetic spectrum. 0:10:17.640 --> 0:10:21.240 But people weren't fully didn't didn't fully understand all this 0:10:21.280 --> 0:10:25.319 at this point, So they are effectively invisible to us, 0:10:25.320 --> 0:10:28.080 and we have no real way of interacting with them 0:10:28.520 --> 0:10:31.280 naturally on our own. But the Hurts came up with 0:10:31.280 --> 0:10:34.960 an experiment. He built an apparatus that included a spark gap. 0:10:35.480 --> 0:10:38.800 That is, it incorporated a pair of electrode terminals that 0:10:38.840 --> 0:10:42.200 are separated by a small gap of empty space just 0:10:42.360 --> 0:10:45.760 air between the two. But if you create a sufficient voltage, 0:10:45.840 --> 0:10:49.920 which remember an electrical circuit, voltage is equivalent to pressure, 0:10:50.360 --> 0:10:53.120 how much UNP is behind the current, if you had 0:10:53.120 --> 0:10:56.480 a sufficient voltage applied across the two terminals, so, in 0:10:56.480 --> 0:11:00.000 other words, the the difference between negative and positive charge 0:11:00.160 --> 0:11:03.760 just so great it allows for an electric discharge to 0:11:03.880 --> 0:11:08.120 pass between the terminals and essentially kind of equalize the pressure, 0:11:08.360 --> 0:11:10.640 so you get a spark. In other words, this is 0:11:10.640 --> 0:11:13.640 the basic principle for stuff like spark plugs in internal 0:11:13.679 --> 0:11:18.040 combustion engine vehicles. Anyway, Hurts created a device that had 0:11:18.080 --> 0:11:20.840 a spark gap in it. He could generate sparks with 0:11:20.880 --> 0:11:24.439 this device, but he also had a loop of wire, 0:11:24.920 --> 0:11:28.480 and the loop of wire ended with a little gap 0:11:28.760 --> 0:11:33.559 between two effectively terminals another spark gap. In other words, 0:11:33.600 --> 0:11:35.760 this one was not connected to a power source, however, 0:11:36.200 --> 0:11:40.280 and he discovered that when he generated a spark with 0:11:40.400 --> 0:11:44.720 his first device, this loop of wire would also have 0:11:44.800 --> 0:11:49.920 a spark get generated between its two ends as long 0:11:49.960 --> 0:11:52.800 as it was within a few meters of the first one. So, 0:11:52.840 --> 0:11:56.479 in other words, spark gap number one acted like a transmitter, 0:11:56.559 --> 0:11:59.640 and spark gap number two, this loop of wire was 0:11:59.679 --> 0:12:01.840 acting like a receiver. Now, I'm not going to go 0:12:01.880 --> 0:12:04.600 into all the actual physics of this, because that would 0:12:04.640 --> 0:12:09.000 require even more discussion of stuff like resonance, capacitance and 0:12:09.240 --> 0:12:13.319 inductance um and and that would just be like this, 0:12:13.600 --> 0:12:16.560 this series would be forty episodes long. I will say 0:12:16.559 --> 0:12:20.120 that it isn't as simple as saying electricity happens over here, 0:12:20.440 --> 0:12:23.200 so it's also happening over here. That would be just 0:12:23.200 --> 0:12:25.440 playing wrong. Now, if you do want me to go 0:12:25.480 --> 0:12:29.800 into a more detailed explanation of how Hurts generated radio 0:12:29.880 --> 0:12:33.360 signals with this, even though he wasn't fully aware of 0:12:33.440 --> 0:12:36.520 exactly what it was he did. I'll do that in 0:12:36.559 --> 0:12:39.360 a future series, but for now we'll just leave it 0:12:39.480 --> 0:12:42.800 as Hurts created a device that generated radio waves and 0:12:42.840 --> 0:12:46.040 discovered a way to detect those waves using a loop 0:12:46.040 --> 0:12:48.400 of wire. But it Hurts didn't think there was any 0:12:48.480 --> 0:12:51.839 real practical use for this. He just saw it as 0:12:51.840 --> 0:12:58.360 a scientific experiment that validated Maxwell's hypothesis regarding electro magnetic radiation. 0:12:58.440 --> 0:13:01.040 He was just saying, this experiment, it proves that Maxwell 0:13:01.120 --> 0:13:04.280 was right, But I can't see any use for this 0:13:04.679 --> 0:13:07.600 apart from that. Now, as it would turn out, this 0:13:07.600 --> 0:13:11.440 would become the basis for early radio communication. Oh and 0:13:11.480 --> 0:13:14.960 by the way, this type of radio communication uh has 0:13:15.000 --> 0:13:19.360 been illegal in the United States since nineteen nine. The 0:13:19.480 --> 0:13:24.160 spark gap transmitter approach against the law in the United States. 0:13:24.240 --> 0:13:28.079 And you might wonder why why is that against the law? Well, 0:13:28.400 --> 0:13:31.439 the signals you generate with a spark gap radio transmitter 0:13:31.880 --> 0:13:35.839 have a very broad frequency range. So if you were, 0:13:36.720 --> 0:13:39.720 you know, close to a spark gap radio transmitter, like 0:13:39.720 --> 0:13:41.839 you're not part of this experiment, right, there's just one 0:13:41.880 --> 0:13:45.200 that's operating somewhere in your area. Well, you might find 0:13:45.640 --> 0:13:50.880 that the transmissions coming from that transmitter are overpowering other ones, 0:13:51.000 --> 0:13:54.360 like broadcast radio signals or you know, maybe later on 0:13:54.520 --> 0:13:57.400 television signals. It all depends on what frequency range it's 0:13:57.480 --> 0:14:01.680 broadcasting in, and radio interference, by definition makes it really 0:14:01.720 --> 0:14:04.680 hard to send and receive signals. So the US federal 0:14:04.720 --> 0:14:08.640 government told amateur radio enthusiasts, hey, there's no way you 0:14:08.679 --> 0:14:11.760 can guarantee your setup is not gonna mess with important systems, 0:14:11.840 --> 0:14:15.080 so please don't use spark gap transmitters. It's it's like 0:14:15.160 --> 0:14:20.160 firing off a blunderbus in a random direction. Not not great. 0:14:20.200 --> 0:14:23.240 It's not precise, so you can't like tune into a 0:14:23.280 --> 0:14:27.640 specific radio frequency. It's more like across this broad range 0:14:27.760 --> 0:14:32.880 of frequencies, that transmission is gonna criss cross all of them. 0:14:33.200 --> 0:14:38.360 So it's not a precise approach to transmission. So later 0:14:38.400 --> 0:14:42.160 engineers would build spark gap systems to transmit information wirelessly. 0:14:42.600 --> 0:14:45.880 But the spark gap method really only allows transmission of 0:14:46.000 --> 0:14:50.080 radio waves over that broad and somewhat random spectrum of frequencies, 0:14:50.360 --> 0:14:54.240 so suitable for sending like a coded message like those 0:14:54.280 --> 0:14:56.640 that are sent by Morse code, because you could just 0:14:56.680 --> 0:15:00.760 send little bursts of radio pulses. But it wasn't a 0:15:00.760 --> 0:15:04.440 good fit for other types of information like audio information. 0:15:04.480 --> 0:15:07.600 There was no way to send voice communications using spark 0:15:07.680 --> 0:15:11.040 gap technology, at least not effectively. And this is where 0:15:11.040 --> 0:15:14.760 Poulson comes in. So you know, you remember Paulson. We 0:15:14.920 --> 0:15:16.800 kind of left off on him a while ago. But 0:15:16.880 --> 0:15:20.360 Poulson developed something called an arc transmitter. And you might 0:15:20.400 --> 0:15:23.320 have heard me talk about transistors and how those would 0:15:23.400 --> 0:15:28.040 end up replacing for the most part, older vacuum tube technology. Well, 0:15:28.120 --> 0:15:32.440 vacuum tubes would end up replacing arc transmitters. So we're 0:15:32.440 --> 0:15:34.920 gonna take a step back from vacuum tubes were right 0:15:34.960 --> 0:15:39.320 in between, uh, you know, the spark transmitters and vacuum tubes. 0:15:39.320 --> 0:15:41.760 At this point, the arc lamp had been around for 0:15:41.840 --> 0:15:45.240 nearly a century. But I'll talk more about how we 0:15:45.240 --> 0:15:48.760 went from an arc lamp to an arc transmitter after 0:15:48.800 --> 0:15:59.760 we come back from this quick break. So our lamps 0:15:59.760 --> 0:16:02.280 had been around for almost a hundred years when Poulson 0:16:02.360 --> 0:16:05.280 starts taking a look at them for the potential of 0:16:05.400 --> 0:16:10.440 using them as a form of a radio transmitter. Let's 0:16:10.520 --> 0:16:12.680 start by defining what an arc lamp is in the 0:16:12.720 --> 0:16:14.560 first place. And I talked about these a bit in 0:16:14.560 --> 0:16:17.680 my episodes about stage lighting. Uh, they have something in 0:16:17.720 --> 0:16:21.520 common with spark gaps. So in our lamp typically has 0:16:21.600 --> 0:16:24.560 a pair of carbon rods. Doesn't always have to be carbon, 0:16:24.600 --> 0:16:28.120 but that's how the early ones were. And you create 0:16:28.200 --> 0:16:33.080 a high voltage between these carbon rods um and you're 0:16:33.160 --> 0:16:37.120 essentially feeding a high voltage current into rod number one 0:16:37.920 --> 0:16:42.000 and it's separated by a gap from rod number two, 0:16:42.600 --> 0:16:45.720 and the carbon in the first rod begins to vaporize. 0:16:45.760 --> 0:16:48.400 Because the carbon rod is gonna heat up due to 0:16:48.440 --> 0:16:52.560 its electrical resistance as this high voltage is pushing current 0:16:52.600 --> 0:16:56.040 through it, so heats up. Some of the carbon atoms 0:16:56.080 --> 0:16:59.760 begin to vaporize, and this allows electricity to flow in 0:16:59.800 --> 0:17:03.560 an arc from rod number one to rod number two. 0:17:04.359 --> 0:17:08.399 The carbon vapor effectively is completing a circuit. Now, this 0:17:08.480 --> 0:17:12.119 means that rod number one is slowly losing mass because 0:17:12.160 --> 0:17:15.440 particles are vaporizing off of the rod, and Rod number 0:17:15.440 --> 0:17:19.000 two is slowly gaining mass because those vaporized particles are 0:17:19.040 --> 0:17:22.880 forming deposits on the rod. And the length of that 0:17:23.000 --> 0:17:26.760 gap ends up being really important for carbon arc lamps. 0:17:27.400 --> 0:17:29.639 If it's too wide of a gap, well, then you're 0:17:29.680 --> 0:17:32.960 gonna get these little starts and stops as the arc forms, 0:17:33.280 --> 0:17:38.000 because the vapor between the two rods will get interrupted. 0:17:38.440 --> 0:17:40.240 So if the gap is too large, you just get 0:17:40.280 --> 0:17:44.040 kind of a sputtering lamp. If it's too close, well 0:17:44.160 --> 0:17:46.280 you'll get an arc that forms, but you'll have a 0:17:46.320 --> 0:17:48.399 limit to how much light is being produced and won't 0:17:48.400 --> 0:17:51.479 be very effective. All right, So that was the basic 0:17:51.800 --> 0:17:56.080 carbon arc lamp. Well, then a brilliant woman named Hertha Arton, 0:17:56.600 --> 0:18:00.359 who married a mathematician named William Martin Um had come 0:18:00.440 --> 0:18:03.439 up with more ideas. So William Martin he had started 0:18:03.480 --> 0:18:06.520 to look into the physics and peculiarities of arc lamps. 0:18:07.280 --> 0:18:09.240 You know, they were already a thing by the time 0:18:09.240 --> 0:18:11.199 he was looking into them. He didn't invent them. He 0:18:11.320 --> 0:18:14.120 was just curious about them because there were certain things 0:18:14.119 --> 0:18:18.920 about them that were interesting and not fully understood. However, 0:18:18.960 --> 0:18:23.199 he became discouraged after his research burned up because arc 0:18:23.280 --> 0:18:26.880 lamps are also dangerous and there was a fire. But 0:18:27.000 --> 0:18:30.240 Hertha took up the torch, so to speak. She was 0:18:30.440 --> 0:18:34.760 a keen student of mathematematics, herself and she continued her 0:18:34.840 --> 0:18:38.679 husband's research on her own. She noted that when she 0:18:38.800 --> 0:18:44.199 generated certain types of arcs at certain voltages, the current 0:18:44.600 --> 0:18:48.880 in the arc would decrease as she increased the voltage. 0:18:48.920 --> 0:18:51.680 And that seemed weird, right, Like she would increase the 0:18:51.760 --> 0:18:56.280 voltage or pressure, but the current, the amount of electricity 0:18:56.280 --> 0:19:00.439 flowing through the arc would decrease. What could is that 0:19:00.520 --> 0:19:07.639 to happen? Well, William, her husband, hypothesized that for you know, 0:19:07.720 --> 0:19:10.439 when he was seeing the current changing, there must be 0:19:10.480 --> 0:19:14.800 some sort of negative resistance, negative electrical resistance in the arc. 0:19:15.480 --> 0:19:17.600 This was not something that was accepted by the science 0:19:17.640 --> 0:19:20.760 community at large, to put it lightly, but one of 0:19:20.920 --> 0:19:25.000 his students, a guy named William Duddell, began studying arc 0:19:25.040 --> 0:19:27.399 lamps and he found something really weird. And he was 0:19:27.440 --> 0:19:30.360 looking at what happened if you changed the current flowing 0:19:30.400 --> 0:19:33.520 to an arc lamp, you know, at at different speeds, 0:19:33.520 --> 0:19:37.600 like if you're changing the current frequently or less frequently, Like, 0:19:37.920 --> 0:19:40.840 how does that affect the arc lamp? And this was 0:19:40.920 --> 0:19:44.600 direct current, right, That's the kind of current that always 0:19:44.640 --> 0:19:47.359 flows in the same direction. It's the type that you 0:19:47.400 --> 0:19:50.280 get if you are drawing electricity from a battery, because 0:19:50.280 --> 0:19:53.000 a battery has a negative terminal and a positive terminal, 0:19:53.320 --> 0:19:56.320 and that's that the electrons flow from the negative toward 0:19:56.400 --> 0:19:59.359 the positive and they're not going to change directions in 0:19:59.400 --> 0:20:03.399 a normal like circuit. But Duddle hooked up his arc 0:20:03.480 --> 0:20:07.760 lamp to a circuit that had a capacitor in it. Now, 0:20:07.760 --> 0:20:11.679 a capacitor consists of two conductive plates that have an 0:20:11.680 --> 0:20:15.679 insulator substance called a dielectric separating the two plates. So 0:20:15.720 --> 0:20:17.639 in the middle, kind of like a sandwich, you have 0:20:17.680 --> 0:20:20.920 conductive plate number one, you get your insulating material, then 0:20:20.920 --> 0:20:23.520 you have conductive plate number two. Now, this allows you 0:20:23.560 --> 0:20:26.119 to build up charges on either side of the plates. 0:20:26.119 --> 0:20:28.719 You can build up a very big negative charge on 0:20:28.720 --> 0:20:31.040 one side and a positive charge on the other, and 0:20:31.080 --> 0:20:35.040 they will hold that charge and opposite charges attract right 0:20:35.400 --> 0:20:38.520 the negative once quote unquote to get over with the 0:20:38.560 --> 0:20:41.160 positive and the positive ones to get over with the negative. 0:20:41.840 --> 0:20:44.720 So if you create a pathway so that the charge 0:20:44.840 --> 0:20:49.000 can actually move from either side and equalize, it will 0:20:49.080 --> 0:20:50.919 do so, and it will do it all at once. 0:20:51.080 --> 0:20:55.160 It will completely dump that charge as soon as there 0:20:55.240 --> 0:20:58.560 is a viable path to do so. So here's a 0:20:58.600 --> 0:21:02.240 simple version of a circuit with a capacitor. Let's say 0:21:02.240 --> 0:21:04.880 you got a battery and you connect a wire from 0:21:04.880 --> 0:21:07.439 the negative terminal of the battery to a light bulb. 0:21:07.920 --> 0:21:11.080 You connect the light bulb to a capacitor, and you 0:21:11.080 --> 0:21:14.440 connect the other side of the capacitor back to the battery. 0:21:14.480 --> 0:21:17.920 So what happens when you have completed this circuit, Well, 0:21:18.000 --> 0:21:21.800 electricity flows from the batteries negative terminal to the light bulb. 0:21:22.080 --> 0:21:25.280 Light bulb lights up, it continues on to the capacitor. 0:21:25.920 --> 0:21:29.800 Now electrons start to accumulate in that plate of the capacitor. 0:21:29.880 --> 0:21:34.199 That capacitor builds up a negative charge. Meanwhile, electrons on 0:21:34.240 --> 0:21:37.600 the opposite plate, the one on the other side of 0:21:37.600 --> 0:21:40.840 the circuit, they start to give up electrons that go 0:21:40.960 --> 0:21:43.840 back to the battery and it builds up a positive charge. 0:21:43.840 --> 0:21:45.960 So you have a positive charge on one side and 0:21:46.000 --> 0:21:48.679 then you have a negative charge on the other. The 0:21:48.720 --> 0:21:51.000 capacitor can actually charge all the way up to the 0:21:51.040 --> 0:21:55.320 same amount of voltage that the battery provides. So if 0:21:55.320 --> 0:21:58.080 it's a one and a half volt battery, the capacitor 0:21:58.119 --> 0:22:01.119 will charge up to one a half volts between the 0:22:01.160 --> 0:22:05.040 two plates, and as it charges up, the light bulb 0:22:05.119 --> 0:22:07.840 will gradually start to dim, and once the capascitor is 0:22:07.880 --> 0:22:11.919 fully charged, the light will just go out. Because the 0:22:11.960 --> 0:22:15.840 current no longer is flowing from the battery, the circuits 0:22:15.880 --> 0:22:18.520 kind of at a standstill. You have equal amounts of pressure, 0:22:19.000 --> 0:22:22.560 so everything just kind of holds. But let's say then 0:22:22.600 --> 0:22:24.639 you remove the battery. So you take the battery out 0:22:24.680 --> 0:22:27.280 of the circuit, the capacitor will still hold on to 0:22:27.359 --> 0:22:31.960 its charge. It still has that that voltage there. And 0:22:32.359 --> 0:22:34.840 if you were to actually put a wire in the 0:22:34.880 --> 0:22:37.640 place of where the battery had been, well, now you've 0:22:37.680 --> 0:22:42.000 completed a pathway so that the electricity can actually flow 0:22:42.040 --> 0:22:45.639 through the circuit, and the electrons on the negatively charged 0:22:45.680 --> 0:22:49.360 plate are gonna rush all at once back through this circuit. 0:22:49.640 --> 0:22:51.679 That means you're going to go back through the lightbulb 0:22:52.080 --> 0:22:55.240 and make the light bulb flash very quickly, and then 0:22:55.280 --> 0:22:57.800 the charge reaches equilibrium and the light bulb goes off 0:22:57.840 --> 0:23:00.160 and everything goes back to normal. The flash bulb, as 0:23:00.200 --> 0:23:04.000 we use in film cameras use capacitors in exactly this 0:23:04.040 --> 0:23:07.280 way to activate that light quickly so that you can 0:23:07.359 --> 0:23:12.879 take a flash picture. Okay, well, Dundal found something really 0:23:12.920 --> 0:23:16.000 weird when he attached his capacitor to his arc lamp. 0:23:16.320 --> 0:23:19.360 He had a loop of wire connected in this circuit 0:23:20.200 --> 0:23:22.040 where he had his capacitor in his arc lamp, and 0:23:22.040 --> 0:23:25.520 he found that this setup creates something really bizarre. First 0:23:25.520 --> 0:23:30.440 of all, it would start humming at a weird musical note, 0:23:30.480 --> 0:23:34.800 like it was a musical kind of hum and also 0:23:35.359 --> 0:23:38.840 it appeared that it was creating alternating current. There was 0:23:38.880 --> 0:23:42.680 an oscillation going on in the flow of current. So 0:23:42.840 --> 0:23:47.000 Dundle discovered if he straightened the loop of wire, the 0:23:47.080 --> 0:23:50.000 humming noise stopped and the arc lamp reverted to plain 0:23:50.040 --> 0:23:53.920 old direct current. So he figured something wild was happening, 0:23:53.920 --> 0:23:57.560 and he learned that the coil and capacitor were creating 0:23:57.840 --> 0:24:00.240 an oscillating signals. So let's go back to that that 0:24:00.440 --> 0:24:04.439 simple capacitor example we just made. You've built up a 0:24:04.520 --> 0:24:07.679 charge between two plates, and you connect the two plates 0:24:07.720 --> 0:24:10.320 together using a coiled wire so that you can have 0:24:10.359 --> 0:24:14.040 an instantaneous discharge, and electrons flow from the negatively charged 0:24:14.119 --> 0:24:17.679 plate and they go through the coiled wire towards the 0:24:17.680 --> 0:24:22.639 positive one. Well, as electrons go through a coiled conductor, 0:24:23.040 --> 0:24:26.560 it generates a magnetic field. That magnetic field actually encourages 0:24:26.600 --> 0:24:30.399 more charged to flow and it will reverse the charges 0:24:30.440 --> 0:24:32.960 that we had in the capacitor. So, in one instance, 0:24:33.040 --> 0:24:36.359 we had a positive plate and a negative plate. We 0:24:36.400 --> 0:24:40.560 connect them with this coil. The negative ends up becoming 0:24:40.600 --> 0:24:45.840