1 00:00:04,240 --> 00:00:07,240 Speaker 1: Welcome to tex Stuff, a production of I Heart Radios, 2 00:00:07,320 --> 00:00:14,240 Speaker 1: How Stuff Works. Hey there, in Welcome to tech Stuff. 3 00:00:14,320 --> 00:00:17,720 Speaker 1: I'm your host, Jonathan Strickland. I'm an executive producer with 4 00:00:17,840 --> 00:00:20,320 Speaker 1: How Stuff Works and I heart Radio and a love 5 00:00:20,320 --> 00:00:22,720 Speaker 1: of all things tech, and it is time for a 6 00:00:22,800 --> 00:00:26,599 Speaker 1: classic episode of tech Stuff. This episode is one I 7 00:00:26,720 --> 00:00:30,520 Speaker 1: referenced in a very recent episode of tech Stuff. In fact, 8 00:00:30,560 --> 00:00:32,519 Speaker 1: it maybe so recent that I don't know if it's 9 00:00:32,520 --> 00:00:35,960 Speaker 1: published yet or not. It's called tex Stuff Gets a 10 00:00:36,040 --> 00:00:40,919 Speaker 1: Bright Idea, and it's all about the real history of 11 00:00:40,960 --> 00:00:44,120 Speaker 1: the light bulb. We often hear that Thomas Edison invented 12 00:00:44,120 --> 00:00:47,000 Speaker 1: the light bulb, but did he for real z s though? 13 00:00:47,680 --> 00:00:51,640 Speaker 1: We find out in this episode. Hey there, I just 14 00:00:51,680 --> 00:00:55,000 Speaker 1: looked up and there he was doing that thing, getting 15 00:00:55,040 --> 00:00:57,520 Speaker 1: my get my energy up. Actually, one of the things 16 00:00:57,560 --> 00:01:01,040 Speaker 1: that uh, you know, we start the episode of pretty traditionally, 17 00:01:01,120 --> 00:01:03,520 Speaker 1: one of the things that we had as an early 18 00:01:03,720 --> 00:01:06,360 Speaker 1: ritual as we recorded Tech Stuff was Jonathan and I 19 00:01:06,360 --> 00:01:09,640 Speaker 1: would be sitting here in the virtual darkness and someone 20 00:01:10,400 --> 00:01:12,800 Speaker 1: we had different engineers over the time over the years now, 21 00:01:12,840 --> 00:01:15,319 Speaker 1: but someone would come in and turn on the lights, yes, 22 00:01:15,400 --> 00:01:22,039 Speaker 1: and usually lighted begs, but we wanted to talk a 23 00:01:22,040 --> 00:01:26,039 Speaker 1: little bit about light, specifically light bulbs today. So what 24 00:01:26,160 --> 00:01:29,120 Speaker 1: a brilliant idea of those were? You know before lightbulbs, 25 00:01:29,840 --> 00:01:32,480 Speaker 1: Before light bulbs, there was no way to indicate that 26 00:01:32,520 --> 00:01:37,959 Speaker 1: you had an idea. Yeah, yeah, there's no there's no yeah, 27 00:01:38,520 --> 00:01:41,559 Speaker 1: pre light bulb there was no ting. Before we get 28 00:01:41,640 --> 00:01:45,480 Speaker 1: into how lightbulbs work in their history and everything, I 29 00:01:45,480 --> 00:01:48,200 Speaker 1: want to lay down a little physics for you. All right, 30 00:01:48,280 --> 00:01:52,560 Speaker 1: go ahead and enlighten us. See what you did much? 31 00:01:52,640 --> 00:01:56,280 Speaker 1: So we are talking about light and what is light? Well, 32 00:01:56,360 --> 00:01:59,880 Speaker 1: light is made up of these very tiny part of 33 00:02:00,000 --> 00:02:07,000 Speaker 1: all like packets called photons. They've got energy, they have momentum, 34 00:02:07,040 --> 00:02:10,800 Speaker 1: but there's one thing they do not have charge accounts 35 00:02:11,040 --> 00:02:16,120 Speaker 1: mass or I was going they have no mass, but 36 00:02:16,240 --> 00:02:20,960 Speaker 1: not no moss. Photons are these packets of energy. They 37 00:02:21,000 --> 00:02:24,840 Speaker 1: have momentum but not mass. And these particles, these these 38 00:02:24,880 --> 00:02:31,200 Speaker 1: photons are emitted by atoms. Once you have excited an 39 00:02:31,240 --> 00:02:34,560 Speaker 1: atom to the point where it's electron starts to move 40 00:02:34,639 --> 00:02:39,480 Speaker 1: out of its normal orbit and goes into a further 41 00:02:39,639 --> 00:02:43,560 Speaker 1: orbit from the atoms nucleus. And once once you remove 42 00:02:43,639 --> 00:02:47,280 Speaker 1: the energy source from that atom, the electron will eventually 43 00:02:47,320 --> 00:02:50,880 Speaker 1: return to its normal orbit around the nucleus. But it 44 00:02:50,960 --> 00:02:55,000 Speaker 1: has to it has to get rid of that energy 45 00:02:55,080 --> 00:02:58,440 Speaker 1: that you have pushed into it. Right, energy is not 46 00:02:58,480 --> 00:03:02,840 Speaker 1: created or destroyed, it's just transferred. So this electron, as 47 00:03:02,840 --> 00:03:05,200 Speaker 1: it's coming back down to its normal orbital is going 48 00:03:05,240 --> 00:03:08,800 Speaker 1: to shed off energy. And in this case, the energy 49 00:03:08,880 --> 00:03:13,480 Speaker 1: is in the form of photons. Now, photons are going 50 00:03:13,520 --> 00:03:17,959 Speaker 1: to be emitted in the entire spectrum of light. Now, humans, 51 00:03:18,440 --> 00:03:22,160 Speaker 1: we are capable of perceiving a narrow band of that 52 00:03:22,280 --> 00:03:28,480 Speaker 1: spectrum called the visible spectrum because it's visible to us. Oh, 53 00:03:28,600 --> 00:03:30,480 Speaker 1: I always wondered about that. This is where the whole 54 00:03:30,560 --> 00:03:33,639 Speaker 1: roy G BIV thing comes in. Right. The different wavelengths 55 00:03:33,639 --> 00:03:38,160 Speaker 1: of light dictate what the color is as we perceive it. Uh. 56 00:03:38,200 --> 00:03:41,720 Speaker 1: The but the the light goes well beyond outside the 57 00:03:41,720 --> 00:03:44,720 Speaker 1: the visible range. There's things like ultra violet and infrared, 58 00:03:44,800 --> 00:03:48,200 Speaker 1: and then you get into electromagnetic radiation as you go 59 00:03:48,360 --> 00:03:52,680 Speaker 1: further out. But and anyway, Uh, these photons can come 60 00:03:52,680 --> 00:03:58,360 Speaker 1: into various forms, so you can have of infrared photon 61 00:03:58,600 --> 00:04:01,960 Speaker 1: or ultra violet photons. So, uh, if it's in the 62 00:04:02,000 --> 00:04:04,520 Speaker 1: visible light spectrum, we're able to see it. Now that's 63 00:04:04,560 --> 00:04:10,080 Speaker 1: important because that's the whole basis of creating a light bulb, 64 00:04:10,120 --> 00:04:12,840 Speaker 1: as you want to create some sort of device that 65 00:04:13,400 --> 00:04:18,120 Speaker 1: you can use to create photons so that you can 66 00:04:18,160 --> 00:04:22,080 Speaker 1: illuminate an area, and before light bulbs, you didn't really 67 00:04:22,120 --> 00:04:24,960 Speaker 1: have that option unless you set something on fire. Uh, 68 00:04:24,960 --> 00:04:26,920 Speaker 1: And there's a limited number of things we can set 69 00:04:26,920 --> 00:04:29,840 Speaker 1: on fire before we set ourselves on fire or we 70 00:04:29,960 --> 00:04:32,800 Speaker 1: run out of stuff that is flammable. So it was 71 00:04:32,839 --> 00:04:35,080 Speaker 1: a good idea to try and develop something that could 72 00:04:35,520 --> 00:04:41,000 Speaker 1: create light in another way. Now, Uh, how do we 73 00:04:41,040 --> 00:04:44,880 Speaker 1: know about how what is the principle upon which light 74 00:04:44,880 --> 00:04:50,120 Speaker 1: bulbs work. Well, again, if you excite an atom and 75 00:04:50,279 --> 00:04:53,240 Speaker 1: you push those electrons out, when the electrons come back in, 76 00:04:53,320 --> 00:04:58,520 Speaker 1: they emit photons. If you give enough energy to an object, 77 00:04:59,120 --> 00:05:02,599 Speaker 1: then you can it enough uh photons for it to 78 00:05:02,640 --> 00:05:05,320 Speaker 1: be within the depending upon the nature of that material, 79 00:05:05,480 --> 00:05:08,400 Speaker 1: for it to be within the visible spectrum for it 80 00:05:08,440 --> 00:05:12,360 Speaker 1: to be perceptible. Because even if it's in the visible spectrum, 81 00:05:12,440 --> 00:05:15,719 Speaker 1: if the energy is not great enough, you won't be 82 00:05:15,760 --> 00:05:19,200 Speaker 1: able to see it. And we're all emitting energy all 83 00:05:19,240 --> 00:05:22,680 Speaker 1: the time, like humans are emitting infrared energy all the time, 84 00:05:22,720 --> 00:05:24,320 Speaker 1: and if you had an infrared camera, you would be 85 00:05:24,320 --> 00:05:26,839 Speaker 1: able to see it even in a perfectly dark room. 86 00:05:27,000 --> 00:05:29,200 Speaker 1: You look at the infrared camera, look at a person, 87 00:05:29,520 --> 00:05:32,680 Speaker 1: you would see light as interpreted by the sensor in 88 00:05:32,720 --> 00:05:35,679 Speaker 1: that camera and converted to visible light for us to see. 89 00:05:35,839 --> 00:05:37,840 Speaker 1: You would be able to see that person because they're 90 00:05:37,839 --> 00:05:42,240 Speaker 1: emitting that infrared light. Well, we may even depending on 91 00:05:42,440 --> 00:05:45,159 Speaker 1: what what, depending on the material, it may even be 92 00:05:45,279 --> 00:05:47,840 Speaker 1: emitting visible light, but it might be emitting at at 93 00:05:47,920 --> 00:05:51,520 Speaker 1: levels so low as to be imperceptible to humans. So 94 00:05:51,560 --> 00:05:54,200 Speaker 1: if you add more energy, you can boost that and 95 00:05:54,240 --> 00:05:58,560 Speaker 1: actually see the visible light. Uh. And this can happen 96 00:05:58,640 --> 00:06:01,720 Speaker 1: with things like soled materials. And there was a fellow 97 00:06:02,440 --> 00:06:09,159 Speaker 1: named John William Draper who in seven demonstrated that solid materials, 98 00:06:09,200 --> 00:06:12,839 Speaker 1: almost all of them, will glow once they reach a 99 00:06:12,880 --> 00:06:19,760 Speaker 1: temperature of seven kelvin. Kelvin's a scientific scale for temperatures. 100 00:06:20,320 --> 00:06:22,919 Speaker 1: Kelvin is what we have when you get to zero 101 00:06:23,000 --> 00:06:26,680 Speaker 1: kelvin that says that's as cold as you can get. 102 00:06:26,720 --> 00:06:30,080 Speaker 1: It actually refers to molecular movement, and at zero kelvin, 103 00:06:30,120 --> 00:06:35,280 Speaker 1: there is no molecular movement. So that's like the deepest 104 00:06:35,360 --> 00:06:40,760 Speaker 1: depths of space. Where there's nothing absolutely absolutely uh So, 105 00:06:40,880 --> 00:06:43,400 Speaker 1: if you wanted to convert that into degrees that we're 106 00:06:43,440 --> 00:06:46,440 Speaker 1: more familiar with most of us anyway, it would be 107 00:06:46,440 --> 00:06:50,000 Speaker 1: about five and twenty five degrees celsius or nine seventy 108 00:06:50,040 --> 00:06:54,560 Speaker 1: seven degrees fahrenheit. And at that temperature, solid materials will 109 00:06:54,560 --> 00:06:58,200 Speaker 1: start to glow. We call it the draper point. Now, 110 00:06:58,520 --> 00:07:02,920 Speaker 1: in order to have a object glow at a uh 111 00:07:02,960 --> 00:07:06,040 Speaker 1: at a at an intensity bright enough for it to illuminate, say, 112 00:07:06,080 --> 00:07:09,160 Speaker 1: a room, you will have to put in more energy 113 00:07:09,240 --> 00:07:12,480 Speaker 1: than that, right, because this is talking about they start 114 00:07:12,520 --> 00:07:14,160 Speaker 1: to glow, but that doesn't mean that they're glowing so 115 00:07:14,240 --> 00:07:16,920 Speaker 1: brightly as to illuminate an entire room. That's where it starts. 116 00:07:17,640 --> 00:07:19,840 Speaker 1: So but you know, you've you've probably seen this. If 117 00:07:19,880 --> 00:07:23,000 Speaker 1: you've ever seen a blacksmith work, then you know the 118 00:07:23,000 --> 00:07:25,160 Speaker 1: blacksmith might be heating up iron and when they take 119 00:07:25,200 --> 00:07:30,160 Speaker 1: that out it's glowing red. Or a glass blower or lava. 120 00:07:30,480 --> 00:07:33,960 Speaker 1: You know, there's lots of stuff that tends to lava. 121 00:07:34,280 --> 00:07:37,119 Speaker 1: It's not all man made, but there's lots of stuff 122 00:07:37,120 --> 00:07:41,960 Speaker 1: out there that um that that demonstrates this. So that's 123 00:07:42,000 --> 00:07:46,440 Speaker 1: the principle. But but the idea behind an electric light 124 00:07:46,560 --> 00:07:52,640 Speaker 1: source actually predates Draper's discovery. Really, yes, back in well 125 00:07:52,880 --> 00:07:56,280 Speaker 1: the early eighteen hundreds. I've seen I've seen reports from 126 00:07:56,320 --> 00:07:58,560 Speaker 1: eighteen o six all the way up to eighteen o nine. 127 00:07:59,040 --> 00:08:03,560 Speaker 1: There's some discrepance's there. But an English chemist and inventor 128 00:08:03,680 --> 00:08:08,680 Speaker 1: named Sir Humphrey Davy, named Humphrey Davy, he was designated 129 00:08:08,680 --> 00:08:13,440 Speaker 1: a night So that's the sir. He connected a battery 130 00:08:13,800 --> 00:08:17,920 Speaker 1: to a strip of charcoal and he used the electricity 131 00:08:17,960 --> 00:08:20,120 Speaker 1: to actually heat up the charcoal to the point where 132 00:08:20,160 --> 00:08:24,680 Speaker 1: it started to glow, which created technically the first electric 133 00:08:24,800 --> 00:08:31,360 Speaker 1: arc lamp. Uh. This was not a viable means of 134 00:08:31,960 --> 00:08:35,440 Speaker 1: illumination as it was hard to do. It required a 135 00:08:35,440 --> 00:08:37,920 Speaker 1: lot of energy. The battery drained really quickly, the carbon 136 00:08:38,000 --> 00:08:42,000 Speaker 1: burned at such a or it got so hot as 137 00:08:42,000 --> 00:08:47,000 Speaker 1: to be incredibly dangerous for uh, say, I don't know 138 00:08:47,160 --> 00:08:50,680 Speaker 1: a typical house. Um. So it was not something that 139 00:08:50,760 --> 00:08:53,760 Speaker 1: was going to immediately be adopted into every household, but 140 00:08:53,800 --> 00:08:59,680 Speaker 1: it was proving a concept. Uh. Also, by the way, 141 00:08:59,720 --> 00:09:02,480 Speaker 1: sir very Davy did go on to invent many things, 142 00:09:02,480 --> 00:09:06,199 Speaker 1: including the Davy lamp, which was not an electrical lamp. 143 00:09:06,520 --> 00:09:08,720 Speaker 1: It was a gas lamp. There was a gas lamp 144 00:09:08,760 --> 00:09:11,680 Speaker 1: that had a mesh screen that would surround the flame, 145 00:09:12,760 --> 00:09:17,040 Speaker 1: so that miners meaning people who mind the earth, not 146 00:09:17,360 --> 00:09:21,960 Speaker 1: people who are underage miners, could take the lamps, although 147 00:09:22,240 --> 00:09:24,320 Speaker 1: depending in England at that point in the time, the 148 00:09:24,400 --> 00:09:28,120 Speaker 1: two may have been the same. Hey, our history has 149 00:09:28,160 --> 00:09:30,839 Speaker 1: not always been a nice one. But the miners could 150 00:09:30,880 --> 00:09:35,000 Speaker 1: take a lamp down below the ground and even if 151 00:09:35,000 --> 00:09:37,760 Speaker 1: they encountered a pocket of gas, the mesh would actually, 152 00:09:37,920 --> 00:09:41,320 Speaker 1: this fine mesh would prevent the gas and the flame 153 00:09:41,800 --> 00:09:45,800 Speaker 1: from making friends and becoming a big boom. Very important 154 00:09:45,800 --> 00:09:51,360 Speaker 1: for miners of both types. So the he did invent that. Again, 155 00:09:51,440 --> 00:09:53,559 Speaker 1: not electrical, but I thought it was an interesting aside. 156 00:09:53,800 --> 00:10:00,640 Speaker 1: Moving ahead back in one Frederick de Moulins, and I'm 157 00:10:00,679 --> 00:10:05,040 Speaker 1: sure I have completely mispronounced his name, and I apologized 158 00:10:05,080 --> 00:10:09,120 Speaker 1: profusely for that. Another Englishman, Yeah it could be. He 159 00:10:09,200 --> 00:10:12,440 Speaker 1: patented a lightbulb in eighteen forty one, and this one 160 00:10:12,520 --> 00:10:15,280 Speaker 1: was comprised of a glass case and a burner or 161 00:10:15,360 --> 00:10:20,120 Speaker 1: burners actually made of carbon and in expensive material you 162 00:10:20,200 --> 00:10:24,960 Speaker 1: may know as platinum. Yeah, you thought that led light 163 00:10:25,000 --> 00:10:29,280 Speaker 1: bulbs were expensive, so uh he he patented that design 164 00:10:29,640 --> 00:10:34,280 Speaker 1: again not really practical for for every day or even 165 00:10:34,320 --> 00:10:40,120 Speaker 1: industrial use. An American inventor named J. W. Starr received 166 00:10:40,160 --> 00:10:43,240 Speaker 1: a patent for a light bulb that used a carbon burner. UM. 167 00:10:43,280 --> 00:10:47,880 Speaker 1: And then the next few decades were spent among inventors 168 00:10:47,880 --> 00:10:50,960 Speaker 1: trying to find a way to perfect the discoveries these 169 00:10:51,000 --> 00:10:55,000 Speaker 1: earlier inventors had found, so that you could create a 170 00:10:55,640 --> 00:11:00,000 Speaker 1: light bulb that made sense, that that was a ficient 171 00:11:00,559 --> 00:11:02,840 Speaker 1: that could light well, that was not going to be 172 00:11:02,880 --> 00:11:07,600 Speaker 1: prohibitively expensive. And there are two names in particular that 173 00:11:07,640 --> 00:11:11,079 Speaker 1: pop up all the time, one of them being probably 174 00:11:11,160 --> 00:11:14,280 Speaker 1: the most famous, uh connected to the light bulb, which 175 00:11:14,320 --> 00:11:18,120 Speaker 1: is Thomas Edison. Yes, it's funny. As we were recording this, 176 00:11:18,160 --> 00:11:22,960 Speaker 1: we are rapidly approaching the hundred thirty third anniversary of 177 00:11:23,040 --> 00:11:26,959 Speaker 1: the first test of Edison's incandescent light bulb. Yeah. Now, 178 00:11:27,040 --> 00:11:29,560 Speaker 1: it is important to note Edison was not the person 179 00:11:29,640 --> 00:11:31,679 Speaker 1: who invented the light bulb. He was not even the 180 00:11:31,720 --> 00:11:34,480 Speaker 1: person to invent the incandescent light bulb, but he was 181 00:11:35,040 --> 00:11:39,360 Speaker 1: someone who perfected that design and made it viable as 182 00:11:39,400 --> 00:11:43,120 Speaker 1: an actual product. Yeah. Now it's it's important to know, 183 00:11:43,640 --> 00:11:47,840 Speaker 1: um that these these early light bulbs. Uh, you know, 184 00:11:47,920 --> 00:11:51,439 Speaker 1: not only were homes not really wired. Actually, the light bulb, 185 00:11:51,480 --> 00:11:55,800 Speaker 1: I would argue, based on my research the over the past, 186 00:11:55,920 --> 00:11:58,040 Speaker 1: you know, the past times that we've done tech stuff. 187 00:11:58,040 --> 00:12:00,079 Speaker 1: We've talked about Edison and Tesla and all these the 188 00:12:00,160 --> 00:12:03,000 Speaker 1: lightbulb actually was sort of the key to getting homes 189 00:12:03,000 --> 00:12:06,920 Speaker 1: wired for electricity. Yeah, I mean you and it made 190 00:12:06,960 --> 00:12:11,240 Speaker 1: sense because suddenly you had households that could be uh 191 00:12:11,559 --> 00:12:16,880 Speaker 1: safely with air quotes around that lit after dark and 192 00:12:17,160 --> 00:12:22,200 Speaker 1: extend the useful uh time human being could get stuff 193 00:12:22,280 --> 00:12:26,679 Speaker 1: done because otherwise, when night fell, we might as well 194 00:12:26,720 --> 00:12:30,319 Speaker 1: just go to bed because it was gonna be pretty dark. Well, 195 00:12:30,360 --> 00:12:32,679 Speaker 1: you know, we're related bed and early to rise, as 196 00:12:32,720 --> 00:12:35,199 Speaker 1: they say, early to bed, early to rise, because otherwise 197 00:12:35,200 --> 00:12:38,000 Speaker 1: you're barking your ship on the coffee table. Well, yeah, 198 00:12:38,080 --> 00:12:42,120 Speaker 1: that's that's true. Well, gas lamps, uh were very very popular. 199 00:12:43,040 --> 00:12:46,040 Speaker 1: But they were I mean, in addition to being obviously 200 00:12:46,080 --> 00:12:51,360 Speaker 1: inherently somewhat dangerous um and oil lamps, but they were 201 00:12:51,520 --> 00:12:57,320 Speaker 1: um smoky, um. They were dirty. So you know, I'm 202 00:12:57,360 --> 00:13:00,120 Speaker 1: sure they probably didn't smell all that great um. But 203 00:13:00,160 --> 00:13:03,760 Speaker 1: the problem with these early lightbulbs is that they weren't 204 00:13:04,040 --> 00:13:10,920 Speaker 1: very practical. Okay, look, I got Yeah. There was another inventor, 205 00:13:11,040 --> 00:13:14,559 Speaker 1: an Englishman, the Englishman named Sir Joseph Swan who was 206 00:13:14,600 --> 00:13:17,120 Speaker 1: working on light bulbs around the same time as Edison, 207 00:13:17,640 --> 00:13:21,760 Speaker 1: and Swan's bulb used carbonized paper as the burner, which 208 00:13:21,880 --> 00:13:25,200 Speaker 1: worked pretty well except that it didn't last terribly long. 209 00:13:25,720 --> 00:13:28,240 Speaker 1: And in fact, this was a problem that a lot 210 00:13:28,280 --> 00:13:33,080 Speaker 1: of lightbulb researchers were encountering that including Edison. The first 211 00:13:33,080 --> 00:13:36,360 Speaker 1: problem was, all right, well, we've we've found uh that 212 00:13:36,440 --> 00:13:41,120 Speaker 1: if you if you run enough electricity through some sort 213 00:13:41,160 --> 00:13:42,800 Speaker 1: of object, you can heat it up enough so that 214 00:13:42,800 --> 00:13:49,199 Speaker 1: it begins to glow. But if that item is exposed 215 00:13:49,280 --> 00:13:53,319 Speaker 1: to oxygen, then it will burn. So even if you 216 00:13:53,360 --> 00:13:56,439 Speaker 1: found a material that does not melt at a high temperature, 217 00:13:56,679 --> 00:13:58,920 Speaker 1: it would burn, It would combust at a high enough 218 00:13:58,920 --> 00:14:01,920 Speaker 1: temperature because it, you know, it would be adjacent to oxygen, 219 00:14:02,000 --> 00:14:05,959 Speaker 1: which you know that that's part of the fuel you need, 220 00:14:06,080 --> 00:14:08,800 Speaker 1: you know, in order to have a fire. UM. So 221 00:14:09,800 --> 00:14:12,199 Speaker 1: the you had to close it off from oxygen, which 222 00:14:12,240 --> 00:14:14,760 Speaker 1: is why there were these these vacuum tubes essentially is 223 00:14:14,760 --> 00:14:21,680 Speaker 1: what they create, these vacuum containers. UM. But Once they 224 00:14:21,680 --> 00:14:23,520 Speaker 1: got through that, they had to find what's the right 225 00:14:23,560 --> 00:14:27,160 Speaker 1: material to use. Actually, what Edison ended up using at 226 00:14:27,240 --> 00:14:33,960 Speaker 1: first was bamboo. He took Japanese bamboo and carbonized it 227 00:14:34,400 --> 00:14:37,400 Speaker 1: and created a filament. And in this case, what a 228 00:14:37,480 --> 00:14:40,920 Speaker 1: filament is is this really long, long, long, long strip 229 00:14:41,160 --> 00:14:44,840 Speaker 1: of material that is then coiled so that you can 230 00:14:44,960 --> 00:14:50,040 Speaker 1: decrease the space that it needs to um to fit 231 00:14:50,120 --> 00:14:52,600 Speaker 1: into whatever you want to put it in. So it's 232 00:14:52,600 --> 00:14:56,600 Speaker 1: got a lot of surface areas. Then the resistance is high. 233 00:14:56,920 --> 00:15:01,720 Speaker 1: A resistance in electricity is the the materials resistance to 234 00:15:01,800 --> 00:15:04,560 Speaker 1: electrons flowing through it freely. The more resistance there is 235 00:15:04,600 --> 00:15:08,640 Speaker 1: in general, okay, you've got greater resistance, you have greater heat. Well, 236 00:15:08,760 --> 00:15:10,840 Speaker 1: the secret to the light here is the amount of 237 00:15:10,880 --> 00:15:13,760 Speaker 1: heat that's being generated. That's the energy that is creating 238 00:15:13,800 --> 00:15:17,320 Speaker 1: this whole system of electrons being pushed out and then 239 00:15:17,400 --> 00:15:19,360 Speaker 1: when they start coming back in, the photons are being 240 00:15:19,960 --> 00:15:24,480 Speaker 1: let out. So let the photons out? Who let the 241 00:15:24,480 --> 00:15:27,280 Speaker 1: photons out? That was as an a swan as it 242 00:15:27,320 --> 00:15:31,360 Speaker 1: turns out. Um. It's interesting because then Edison Edison ended 243 00:15:31,440 --> 00:15:35,120 Speaker 1: up hiring what his first his first light bulb design 244 00:15:35,280 --> 00:15:39,840 Speaker 1: used a temperature controlled switch to try and keep the 245 00:15:40,080 --> 00:15:43,840 Speaker 1: material at the right temperature so that it would the 246 00:15:43,960 --> 00:15:47,160 Speaker 1: light bulb would remain lit longer, because I was an 247 00:15:47,160 --> 00:15:49,680 Speaker 1: early problem with these light bulbs is that their their 248 00:15:49,800 --> 00:15:52,520 Speaker 1: utility was low because they couldn't couldn't burn them for 249 00:15:52,600 --> 00:15:56,800 Speaker 1: very long. But this was a problem because the the 250 00:15:56,880 --> 00:15:59,840 Speaker 1: temperature control controlled switch, once a certain temperature was hit, 251 00:15:59,880 --> 00:16:03,280 Speaker 1: it switch off right the light would go off, And 252 00:16:03,320 --> 00:16:06,320 Speaker 1: so I started creating this flickering problem and made the 253 00:16:06,360 --> 00:16:11,120 Speaker 1: bulb practically unusable. So he then hired a physicist from 254 00:16:11,120 --> 00:16:17,040 Speaker 1: Princeton named Francis Upton, who led Edison's research team working 255 00:16:17,080 --> 00:16:20,440 Speaker 1: on light bulbs, to start practicing with other stuff. That's 256 00:16:20,440 --> 00:16:22,480 Speaker 1: when they came upon the idea of using the bamboo 257 00:16:22,520 --> 00:16:27,160 Speaker 1: as a filament. Um. Swan and Edison ended up battling 258 00:16:27,160 --> 00:16:31,040 Speaker 1: each other. Edison ended up taking patent lawsuits against Swan, 259 00:16:31,200 --> 00:16:34,480 Speaker 1: but then ultimately the two of them formed a partnership 260 00:16:34,520 --> 00:16:41,880 Speaker 1: together and they created the Edison Swan United Company. Teamwork teamwork. Um. Yeah, 261 00:16:42,200 --> 00:16:44,880 Speaker 1: just so, just so you guys know, patent wars are 262 00:16:44,920 --> 00:16:49,600 Speaker 1: not a new thing. Oh no, not in the least. Um. Yeah, 263 00:16:49,800 --> 00:16:53,440 Speaker 1: it's funny. While while carbonized bamboo sounds like an ingredient 264 00:16:53,560 --> 00:16:58,560 Speaker 1: for a hipster sandwich. Um, it did have the ability 265 00:16:58,600 --> 00:17:03,840 Speaker 1: to burn for more than which you know back in 266 00:17:03,920 --> 00:17:06,159 Speaker 1: that time, that was pretty nice for a for a 267 00:17:06,200 --> 00:17:10,920 Speaker 1: light bulb. Yeah, and uh, this served as the basis 268 00:17:10,960 --> 00:17:14,000 Speaker 1: for what future light bulbs would be and then we 269 00:17:14,400 --> 00:17:16,919 Speaker 1: ended up shifting to a different type of filament. But 270 00:17:16,920 --> 00:17:18,520 Speaker 1: we'll get into that in a second. So let's talk 271 00:17:18,560 --> 00:17:23,680 Speaker 1: about the basic anatomy of an incandescent light bulb. And 272 00:17:23,720 --> 00:17:26,600 Speaker 1: don't worry florests and an l e defense. We're going 273 00:17:26,640 --> 00:17:29,880 Speaker 1: to get to you too. You just sit tight. So 274 00:17:30,240 --> 00:17:35,520 Speaker 1: the incandescent bulb, you've got two contacts to two electrical 275 00:17:35,560 --> 00:17:39,359 Speaker 1: context on this on a typical incandescent bulb. One of 276 00:17:39,400 --> 00:17:41,960 Speaker 1: them is at the very end of the bulb, that's 277 00:17:42,000 --> 00:17:45,439 Speaker 1: the base of the bulb, and the other is in 278 00:17:45,680 --> 00:17:50,920 Speaker 1: the actual treads that you screw into your um light 279 00:17:50,920 --> 00:17:55,200 Speaker 1: bulb sucket. Yeah. Actually usually has a squeaky noise which 280 00:17:55,520 --> 00:17:58,720 Speaker 1: has that perfect pitch to give me the heb gbs. 281 00:17:59,200 --> 00:18:01,119 Speaker 1: It's like the finger nae else on the chalkboard type thing. 282 00:18:01,160 --> 00:18:04,240 Speaker 1: It's like almost every single light bulb in my house 283 00:18:04,320 --> 00:18:09,800 Speaker 1: makes that noise. And so it's a physically demanding task 284 00:18:09,920 --> 00:18:13,240 Speaker 1: for me because well, I guess psychologically really more than physically, 285 00:18:13,760 --> 00:18:17,960 Speaker 1: because I I suffer trauma. One follows the other. You 286 00:18:18,000 --> 00:18:20,320 Speaker 1: start to how many how many Jonathans does it take 287 00:18:20,320 --> 00:18:23,560 Speaker 1: to you screw the light bulb? Well, after the first one, 288 00:18:23,600 --> 00:18:25,960 Speaker 1: it takes a few others to calm them down. Yeah, 289 00:18:26,040 --> 00:18:28,960 Speaker 1: I'm not afraid of the dark. I'm just afraid of 290 00:18:29,040 --> 00:18:31,879 Speaker 1: changing light bulbs. So that's not really true. I just 291 00:18:31,960 --> 00:18:34,800 Speaker 1: don't like doing it. But anyway, these metal contacts are 292 00:18:34,800 --> 00:18:39,600 Speaker 1: what create the the circuit, right, so that the circuits 293 00:18:39,640 --> 00:18:44,240 Speaker 1: complete when these two contacts are are in contact with 294 00:18:44,400 --> 00:18:48,520 Speaker 1: the rest of the electrical system. To one um, the 295 00:18:48,760 --> 00:18:53,000 Speaker 1: contacts are attached to some wires and those wires are 296 00:18:53,000 --> 00:18:57,119 Speaker 1: attached to the filament. Now, in this case, the filament 297 00:18:57,160 --> 00:19:01,520 Speaker 1: is no longer bamboo. For your typical incandescent, it's usually tungsten. 298 00:19:02,160 --> 00:19:05,399 Speaker 1: And the reason why it's tungsten is a couple of 299 00:19:05,440 --> 00:19:08,560 Speaker 1: different reasons. One is that the melting temperature of tungsten 300 00:19:08,720 --> 00:19:12,480 Speaker 1: is really high, so you can heat tungsten up quite 301 00:19:12,520 --> 00:19:16,840 Speaker 1: a bit and not worry about it being um melting 302 00:19:16,840 --> 00:19:20,000 Speaker 1: away that that that's obviously another issue with light bulbs. Right, 303 00:19:20,040 --> 00:19:22,760 Speaker 1: you heat up materials, some material is gonna melt, and 304 00:19:22,800 --> 00:19:25,640 Speaker 1: it might melt before you hit that draper point, which 305 00:19:25,640 --> 00:19:28,080 Speaker 1: would be bad because you wouldn't get any light out 306 00:19:28,119 --> 00:19:31,000 Speaker 1: of it. You would just get a you know, a 307 00:19:31,040 --> 00:19:36,120 Speaker 1: glass cylinder of hot molten sludge. Um hot molten sludge 308 00:19:36,160 --> 00:19:38,720 Speaker 1: would be a great name for a band. It is. 309 00:19:39,200 --> 00:19:42,320 Speaker 1: It is, however, very thin. The filament is very thin, 310 00:19:42,400 --> 00:19:46,280 Speaker 1: as anyone who has uh smacked a light bulb hard 311 00:19:46,400 --> 00:19:49,119 Speaker 1: enough to break the filament but not hard enough to 312 00:19:49,160 --> 00:19:52,960 Speaker 1: break the glass knows that's really annoying. That's another really 313 00:19:52,960 --> 00:19:57,840 Speaker 1: annoying thing about changing light bulbs. Oh man did I Yeah, 314 00:19:58,119 --> 00:20:01,040 Speaker 1: just ruined it perfectly good by bulbs. So yeah, it's 315 00:20:01,119 --> 00:20:04,800 Speaker 1: very thin again, that's to increase resistance. That's another thing. 316 00:20:04,840 --> 00:20:10,280 Speaker 1: Is that a a a copper wire, for example, the 317 00:20:10,280 --> 00:20:13,159 Speaker 1: the greater the diameter of a copper wire, the lower 318 00:20:13,200 --> 00:20:18,360 Speaker 1: the resistance. So if you have a very um thin 319 00:20:18,480 --> 00:20:21,040 Speaker 1: copper wire, the resistance is greater. That means it's going 320 00:20:21,080 --> 00:20:23,600 Speaker 1: to also generate more heat as a result. Well, this tungsten, 321 00:20:23,720 --> 00:20:26,879 Speaker 1: same thing. I mean, this same principle applies across all materials. 322 00:20:27,520 --> 00:20:32,040 Speaker 1: Tungsten filament is very very very thin. It's actually coiled twice. 323 00:20:33,160 --> 00:20:36,160 Speaker 1: The first coil is done to decrease it's you know, 324 00:20:36,440 --> 00:20:39,280 Speaker 1: the length, and then after you've coiled it once, you 325 00:20:39,359 --> 00:20:43,560 Speaker 1: coil it a second time around. Uh. These these support 326 00:20:43,600 --> 00:20:49,560 Speaker 1: wires and UH that helps when the tungsten heats up, 327 00:20:49,640 --> 00:20:53,399 Speaker 1: it starts to generate, you know, give off these photons. Uh. 328 00:20:53,520 --> 00:20:57,399 Speaker 1: It helps, uh concentrate that light so that you have 329 00:20:57,560 --> 00:21:00,200 Speaker 1: enough for it to be useful. Because again, you want 330 00:21:00,200 --> 00:21:02,320 Speaker 1: to give enough energy there for you to have visible 331 00:21:02,400 --> 00:21:05,200 Speaker 1: light that you can actually see stuff by, but you 332 00:21:05,240 --> 00:21:06,840 Speaker 1: don't want to have to pour in more energy than 333 00:21:07,119 --> 00:21:10,240 Speaker 1: was necessary. And we should point out incandescent bulbs not 334 00:21:10,600 --> 00:21:15,560 Speaker 1: terribly efficient. No, we think about heat being a a 335 00:21:15,600 --> 00:21:19,320 Speaker 1: wasted form of energy in this case, and how hot 336 00:21:19,359 --> 00:21:22,919 Speaker 1: and incandescent bulb gets. And it's also giving out photons 337 00:21:22,960 --> 00:21:28,000 Speaker 1: outside the range of visible light, so you're getting you know, 338 00:21:28,119 --> 00:21:31,200 Speaker 1: infrared light and maybe even ultraviolet light from from these 339 00:21:31,280 --> 00:21:34,240 Speaker 1: light bulbs. Well that that means that again it's a 340 00:21:34,320 --> 00:21:36,560 Speaker 1: drop in efficiency. I mean, yeah, it's giving off light, 341 00:21:36,600 --> 00:21:38,439 Speaker 1: but we can't see it, so it doesn't do us 342 00:21:38,480 --> 00:21:42,480 Speaker 1: any good, not not in a normal application. Anyway, you know, 343 00:21:43,080 --> 00:21:46,440 Speaker 1: if you're doing something that required infrared or ultraviolet light, 344 00:21:46,440 --> 00:21:48,520 Speaker 1: than sure, although there are better ways of doing that 345 00:21:48,520 --> 00:21:51,560 Speaker 1: than using a regular incandescent light bulb. I mean you 346 00:21:51,720 --> 00:21:54,960 Speaker 1: you could you could even cook brownies with it, which 347 00:21:55,000 --> 00:21:58,200 Speaker 1: is with an easy bake oven. It's funny because I 348 00:21:58,359 --> 00:22:01,760 Speaker 1: don't think people not everyone realizes this. It's not like 349 00:22:01,800 --> 00:22:06,000 Speaker 1: a secret. But um, the the older easy bake ovens, especially, 350 00:22:06,000 --> 00:22:08,359 Speaker 1: they're they're essentially using the heat from a lightbulb to 351 00:22:08,560 --> 00:22:12,679 Speaker 1: cook uh, you know, very simple cakes and brownies and 352 00:22:12,720 --> 00:22:17,040 Speaker 1: things like that. Right now, the you know, you might 353 00:22:17,080 --> 00:22:20,200 Speaker 1: ask what's inside a lightbulb? Besides all this stuff, there's 354 00:22:20,200 --> 00:22:23,240 Speaker 1: actually a gas that's inside most incandescent light bulbs, and 355 00:22:23,280 --> 00:22:25,679 Speaker 1: it's usually are gone, which is an uh it's an 356 00:22:25,680 --> 00:22:29,800 Speaker 1: inert gas, meaning it does not react to other stuff. Hey, 357 00:22:29,800 --> 00:22:34,880 Speaker 1: are gone gas. That's a tornado outside. Yeah, So like, oh, 358 00:22:34,960 --> 00:22:37,520 Speaker 1: you never do anything now that you want it to 359 00:22:37,560 --> 00:22:41,720 Speaker 1: be inert because obviously, like something like oxygen, then the 360 00:22:41,760 --> 00:22:46,240 Speaker 1: tungsten would start to burn. It would dramatically decrease the 361 00:22:46,320 --> 00:22:50,080 Speaker 1: life lifespan of your average light bulb. So they pump 362 00:22:50,160 --> 00:22:53,400 Speaker 1: the oxygen, they pump air out of the glass. Globe 363 00:22:53,920 --> 00:22:57,320 Speaker 1: and fill it with are gone gas. Yep. And so 364 00:22:57,520 --> 00:22:59,600 Speaker 1: you might say, well, why why not just have a 365 00:22:59,680 --> 00:23:03,960 Speaker 1: vacu mist of argon gas. The reason for that is that, uh, 366 00:23:04,000 --> 00:23:07,120 Speaker 1: at that high temperature, you have another problem besides combustion, 367 00:23:07,200 --> 00:23:09,800 Speaker 1: even if you don't have auction, the other problem is evaporation. 368 00:23:11,119 --> 00:23:15,600 Speaker 1: Atoms from the tungsten will actually evaporate off the filament 369 00:23:15,680 --> 00:23:18,760 Speaker 1: because of those high temperatures, and over time that means 370 00:23:18,760 --> 00:23:21,000 Speaker 1: that you're losing you know, every time you're using that 371 00:23:21,080 --> 00:23:25,000 Speaker 1: light bulb, you're losing tungsten. With the old light bulb, Yeah, 372 00:23:25,640 --> 00:23:27,639 Speaker 1: and with the old light bulbs, you would actually have 373 00:23:27,840 --> 00:23:31,240 Speaker 1: the tungsten start to evaporate away and coat the inside 374 00:23:31,280 --> 00:23:32,920 Speaker 1: of the light bulbs, So the light bulb would get 375 00:23:33,200 --> 00:23:36,360 Speaker 1: more and more dim both because there was less filament 376 00:23:36,440 --> 00:23:39,200 Speaker 1: to light and because all the filament that was gone 377 00:23:39,280 --> 00:23:41,800 Speaker 1: is now coating the inside of the light bulb making 378 00:23:41,840 --> 00:23:46,000 Speaker 1: it darker. So by using argon, what it actually acts 379 00:23:46,040 --> 00:23:48,760 Speaker 1: as a sort of a sort of a barrier. These 380 00:23:48,840 --> 00:23:53,679 Speaker 1: atoms from tungsten will come off the filament, bump into 381 00:23:53,920 --> 00:23:58,520 Speaker 1: a an argon atom, and then because argon's a nerd, 382 00:23:58,560 --> 00:24:02,000 Speaker 1: it's not going to act with that. That um energy, 383 00:24:02,520 --> 00:24:05,600 Speaker 1: or that that particle rather the particle then returns to 384 00:24:07,080 --> 00:24:11,679 Speaker 1: the strip of tungsten um. So it acts as kind 385 00:24:11,680 --> 00:24:15,240 Speaker 1: of a cushion. It's just pushing the the atoms back 386 00:24:15,359 --> 00:24:18,679 Speaker 1: to the tungsten. Keeping that filament last to last longer 387 00:24:19,640 --> 00:24:23,639 Speaker 1: very important. And so that's the basic premise behind these 388 00:24:23,720 --> 00:24:28,320 Speaker 1: incandescent bulbs. They you know, they get to a pretty 389 00:24:29,160 --> 00:24:33,919 Speaker 1: hot temperature. We're talking around degrees celsius or four thousand 390 00:24:33,960 --> 00:24:38,280 Speaker 1: degrees fahrenheit um. Because again, you want to put out 391 00:24:38,400 --> 00:24:40,560 Speaker 1: enough visible light for it to be useful. Now that 392 00:24:40,600 --> 00:24:45,440 Speaker 1: all depends on the wattage of the bulb. Yeah, which 393 00:24:46,040 --> 00:24:49,359 Speaker 1: generally speaking, you can think of his brightness, um, it's 394 00:24:49,400 --> 00:24:52,840 Speaker 1: it's kind of or or really you can think of 395 00:24:52,880 --> 00:24:55,960 Speaker 1: his brightness or how hot that tungsten's getting inside the 396 00:24:56,080 --> 00:25:01,880 Speaker 1: light bulb. That's what that kind of translates into. Uh 397 00:25:01,920 --> 00:25:04,359 Speaker 1: and UH interesting. We have an article on the site 398 00:25:04,359 --> 00:25:07,240 Speaker 1: how light Bulbs Work and how stuff Works dot com. 399 00:25:07,520 --> 00:25:11,200 Speaker 1: Great article, great illustrations, a fun read. I mean, I 400 00:25:11,560 --> 00:25:13,960 Speaker 1: really do think that it's actually you would think it's 401 00:25:14,000 --> 00:25:15,879 Speaker 1: an article about light bulbs, but it really is a 402 00:25:15,880 --> 00:25:19,960 Speaker 1: fun read. And one of my favorite UH facts in 403 00:25:20,000 --> 00:25:23,760 Speaker 1: this is that a typical sixty what bulb has a 404 00:25:23,800 --> 00:25:27,520 Speaker 1: tongusten filament that is six and a half feet or 405 00:25:27,640 --> 00:25:31,600 Speaker 1: two meters long and one hundred of an inch thick. 406 00:25:31,760 --> 00:25:35,040 Speaker 1: I don't have the centimeters for that, sorry, but it's 407 00:25:35,600 --> 00:25:37,680 Speaker 1: you know, six and a half feet long or two 408 00:25:37,680 --> 00:25:42,120 Speaker 1: meters And if you were to completely uncoil that filament, however, 409 00:25:42,280 --> 00:25:46,440 Speaker 1: once it's all double coiled, it's in a space that's 410 00:25:46,840 --> 00:25:50,119 Speaker 1: shorter than you know, the tip of your pinkie finger, 411 00:25:50,640 --> 00:25:53,520 Speaker 1: and you're thinking, wow, that's to go from six and 412 00:25:53,560 --> 00:25:57,679 Speaker 1: a half feet to that is pretty impressive, you know. 413 00:25:57,760 --> 00:26:00,399 Speaker 1: And again that's packing all that material and so it 414 00:26:00,440 --> 00:26:02,800 Speaker 1: can give off enough light for it to be useful. 415 00:26:03,320 --> 00:26:05,560 Speaker 1: I just got my own bright idea, which means a 416 00:26:05,640 --> 00:26:07,560 Speaker 1: light bulb just went off over my head. And that 417 00:26:07,640 --> 00:26:19,439 Speaker 1: idea is, will now take a quick break, do you uh? 418 00:26:19,640 --> 00:26:22,400 Speaker 1: If you happen to know how three way light bulbs work. 419 00:26:22,600 --> 00:26:25,199 Speaker 1: I do not. Actually, as a matter of fact, we 420 00:26:25,240 --> 00:26:28,480 Speaker 1: have another very very short article on how three way 421 00:26:28,520 --> 00:26:32,080 Speaker 1: light bulbs work, and they also have two filaments. Um, 422 00:26:32,119 --> 00:26:35,200 Speaker 1: it's it's very interesting. Now the socket has to accommodate 423 00:26:35,280 --> 00:26:39,160 Speaker 1: that because it has to do also with a connection 424 00:26:40,040 --> 00:26:42,919 Speaker 1: on the outside. But essentially what happens is that the 425 00:26:42,960 --> 00:26:47,080 Speaker 1: socket is, you know, through a switch, providing instructions on 426 00:26:47,080 --> 00:26:50,719 Speaker 1: which of the two filaments to light. So for the 427 00:26:50,920 --> 00:26:54,320 Speaker 1: first on switch, if you ever use a three way light, 428 00:26:54,440 --> 00:26:56,479 Speaker 1: you know that the first one is the lowest setting 429 00:26:56,840 --> 00:26:59,680 Speaker 1: uses the least amount of electricity. Well, the one filament 430 00:27:00,000 --> 00:27:03,520 Speaker 1: that is designed for that lower setting comes on when 431 00:27:03,520 --> 00:27:06,800 Speaker 1: you click the switch. Again, that provides instructions for the 432 00:27:06,880 --> 00:27:09,680 Speaker 1: second filament, but only the second filament to come on, 433 00:27:10,080 --> 00:27:13,119 Speaker 1: and then the third the two team up. I see, 434 00:27:13,160 --> 00:27:16,199 Speaker 1: So that and then that the off got you. You 435 00:27:16,240 --> 00:27:19,000 Speaker 1: get these the sum total of light coming from the bulb, 436 00:27:19,080 --> 00:27:22,000 Speaker 1: which is, if you'll pardon upon a brilliant way to 437 00:27:22,119 --> 00:27:25,320 Speaker 1: do that because it's very simple, shiny. So moving on. 438 00:27:25,960 --> 00:27:28,560 Speaker 1: That's a little just aside and firefly reference for you 439 00:27:28,560 --> 00:27:31,080 Speaker 1: guys out there. And of course you can achieve different 440 00:27:31,080 --> 00:27:33,639 Speaker 1: effects to what the kind of glass you might be wondering, 441 00:27:33,680 --> 00:27:37,199 Speaker 1: you know what the natural lighting or the what does 442 00:27:37,240 --> 00:27:39,440 Speaker 1: the blue what's the blue one do? Well, it's it's 443 00:27:39,480 --> 00:27:44,760 Speaker 1: just diffusing the uh photons given off by the tungusten 444 00:27:44,840 --> 00:27:47,119 Speaker 1: inside the light bulb a little bit different and I 445 00:27:47,119 --> 00:27:49,560 Speaker 1: should point out a neat that depending upon the material 446 00:27:49,600 --> 00:27:52,240 Speaker 1: you're using, that will determine what kind of light is 447 00:27:52,280 --> 00:27:56,000 Speaker 1: given off. Right, So tungsten's giving off this light, uh, 448 00:27:56,200 --> 00:27:59,680 Speaker 1: partially because of the fact that it's tungsten. But other 449 00:27:59,760 --> 00:28:02,480 Speaker 1: materi areals give off different kinds of light, different colors 450 00:28:02,480 --> 00:28:07,920 Speaker 1: of light along or or essentially lights that are different wavelengths, right, 451 00:28:08,000 --> 00:28:11,640 Speaker 1: so different parts of the spectrum, sometimes visible, sometimes not. Uh. 452 00:28:11,680 --> 00:28:14,600 Speaker 1: This is used in chemistry, it's used in astronomy, it's 453 00:28:14,680 --> 00:28:16,959 Speaker 1: used in lots of different areas of physics, not just 454 00:28:17,160 --> 00:28:20,560 Speaker 1: in creating light bulbs or you know, heating stuff up 455 00:28:20,640 --> 00:28:25,679 Speaker 1: until it glows. But that kind of that's kind of 456 00:28:25,680 --> 00:28:28,240 Speaker 1: the full discussion on incandescent bulbs. But those aren't the 457 00:28:28,280 --> 00:28:35,320 Speaker 1: only kind of bulbs we have. We also have fluorescent bulbs. Yes. Um, 458 00:28:35,440 --> 00:28:39,680 Speaker 1: you might say, well, you know, uh, Edison and later 459 00:28:39,920 --> 00:28:44,120 Speaker 1: the company that he was directly slash indirectly the founder 460 00:28:44,160 --> 00:28:47,440 Speaker 1: of General Electric, you know, perfected the the incandescent light 461 00:28:47,440 --> 00:28:50,440 Speaker 1: bulb and uh uh you know you would think that 462 00:28:50,480 --> 00:28:53,160 Speaker 1: they would be very upset that the fluorescent came out. 463 00:28:53,200 --> 00:28:56,240 Speaker 1: Well not really, because, as we touched on on our 464 00:28:56,400 --> 00:29:01,920 Speaker 1: famous or infamous GE series How How Influence Famous? That's 465 00:29:02,040 --> 00:29:05,600 Speaker 1: more than the series on G E G. E was 466 00:29:05,640 --> 00:29:08,880 Speaker 1: actually in development of the fluorescent light bulb. Yeah, so 467 00:29:09,000 --> 00:29:13,800 Speaker 1: fluorescent lightbulbs use a different method of generating light, so 468 00:29:14,040 --> 00:29:17,760 Speaker 1: you're not you don't have that physical filament inside a 469 00:29:17,800 --> 00:29:22,160 Speaker 1: fluorescent bulb. Instead, what you have is a sealed glass tube. 470 00:29:22,200 --> 00:29:24,720 Speaker 1: By the way, we also have how fluorescent lamps work 471 00:29:25,760 --> 00:29:28,480 Speaker 1: at how stuff Works dot com. So again you should 472 00:29:28,520 --> 00:29:31,440 Speaker 1: read that if you're interested to learn all the physics 473 00:29:31,480 --> 00:29:34,880 Speaker 1: involved in this. But in general, you've got a sealed 474 00:29:34,920 --> 00:29:37,880 Speaker 1: glass tube and not the animal that Chris was alluding 475 00:29:37,920 --> 00:29:42,640 Speaker 1: to earlier. It's just completely sealed. Uh. The tube has 476 00:29:42,720 --> 00:29:46,760 Speaker 1: inside it's some mercury and there's also an inert gas 477 00:29:46,800 --> 00:29:51,680 Speaker 1: like again are gone. Uh. The inside of this glass 478 00:29:51,720 --> 00:29:57,760 Speaker 1: tube is coated with a powder that's phosphorus. Now, phosphorus 479 00:29:57,800 --> 00:30:02,240 Speaker 1: means that when light stri exit, it gives off light. 480 00:30:03,520 --> 00:30:08,200 Speaker 1: So that sounds like it could be totally useless, except 481 00:30:08,360 --> 00:30:12,880 Speaker 1: we're talking about light within the entire spectrum. So even 482 00:30:13,080 --> 00:30:16,120 Speaker 1: if if you have a certain kind of phosphor, it 483 00:30:16,200 --> 00:30:19,400 Speaker 1: will um if you were to hit that phosphor with 484 00:30:19,520 --> 00:30:22,680 Speaker 1: light that's outside the visible spectrum. For example, ultraviolet light, 485 00:30:24,040 --> 00:30:27,280 Speaker 1: and then that phosphor actually emits visible light. That becomes 486 00:30:27,360 --> 00:30:30,959 Speaker 1: useful because you can either look at stuff that is 487 00:30:31,080 --> 00:30:35,160 Speaker 1: in the presence of light that's otherwise outside our our 488 00:30:35,560 --> 00:30:38,880 Speaker 1: field of vision, or you can create something like a 489 00:30:38,880 --> 00:30:43,280 Speaker 1: fluorescent light bulb that uses light outside of our vision 490 00:30:43,280 --> 00:30:45,880 Speaker 1: to create light that's inside our vision. The way this 491 00:30:45,960 --> 00:30:49,160 Speaker 1: works is you've got the electrodes at either end of 492 00:30:49,160 --> 00:30:53,400 Speaker 1: this tube that are wired to some sort of circuit. Now, 493 00:30:53,440 --> 00:30:57,680 Speaker 1: the circuit, once we turn that on, starts to introduce uh, 494 00:30:57,960 --> 00:31:01,320 Speaker 1: free flowing electrons into the gas. Now this is different 495 00:31:01,800 --> 00:31:06,560 Speaker 1: from the filament approach because then you have electrons running 496 00:31:06,560 --> 00:31:09,840 Speaker 1: through a material directly right, just like you would a 497 00:31:09,840 --> 00:31:11,920 Speaker 1: wire in a circuit. I mean, that's essentially what it 498 00:31:12,000 --> 00:31:17,080 Speaker 1: is with this. It's free flowing electrons going through uh. 499 00:31:17,640 --> 00:31:20,520 Speaker 1: The gas in this case AREGNE. It takes a little 500 00:31:20,520 --> 00:31:24,160 Speaker 1: while for these electrons to be introduced into this this tube, 501 00:31:24,440 --> 00:31:27,520 Speaker 1: which is why when you turn on most fluorescent light 502 00:31:27,520 --> 00:31:31,920 Speaker 1: bulbs there's this little flickering moment while it's coming on. Ye. 503 00:31:32,760 --> 00:31:36,600 Speaker 1: The cause, again, the the has to introduce the the 504 00:31:36,600 --> 00:31:40,840 Speaker 1: free flowing electrons for this to work. So once these 505 00:31:40,880 --> 00:31:46,840 Speaker 1: electrons with considerable voltage are introduced. UH, the energy starts 506 00:31:46,880 --> 00:31:49,560 Speaker 1: to change some of the mercury that's in that tube 507 00:31:50,040 --> 00:31:56,040 Speaker 1: from liquid to gas. Now, again, when we're introducing electricity 508 00:31:56,160 --> 00:32:00,680 Speaker 1: into or energy into an atom, it's exciting those electrons, 509 00:32:00,840 --> 00:32:03,640 Speaker 1: pushing them out of their orbitals. UH. And then when 510 00:32:03,680 --> 00:32:05,800 Speaker 1: the electrons start to come back down to their normal 511 00:32:05,960 --> 00:32:09,720 Speaker 1: orbital they'll give off photons. With the case of mercury, 512 00:32:10,640 --> 00:32:14,040 Speaker 1: you're talking about light photons that are in the ultra 513 00:32:14,240 --> 00:32:18,880 Speaker 1: violet wavelength range. So again you can you are exciting 514 00:32:18,880 --> 00:32:22,280 Speaker 1: the mercury and it's giving off ultra violet light. We 515 00:32:22,400 --> 00:32:27,080 Speaker 1: can't see ultraviolet light unaided anyway, we're incapable of seeing 516 00:32:27,200 --> 00:32:30,800 Speaker 1: light at that wavelength. But by coding the inside of 517 00:32:30,840 --> 00:32:34,960 Speaker 1: that tube with phosphors that are able to absorb ultra 518 00:32:35,000 --> 00:32:37,960 Speaker 1: violet light and then emit light in the visible spectrum, 519 00:32:38,280 --> 00:32:42,440 Speaker 1: we can use that ultraviolet light two give us light 520 00:32:42,480 --> 00:32:46,560 Speaker 1: we can see indirectly. We have this intermediary step with 521 00:32:46,640 --> 00:32:51,800 Speaker 1: the phosphors. So the mercury starts to go from liquid 522 00:32:51,840 --> 00:32:55,760 Speaker 1: to gas, gives off these ultraviolet photons. The ultraviolet photons 523 00:32:55,800 --> 00:32:58,920 Speaker 1: hit the phosphors. The phosphors absorbed the ultra violet light 524 00:32:58,920 --> 00:33:02,360 Speaker 1: and emit light in the visible spectrum, and voila or 525 00:33:02,600 --> 00:33:06,280 Speaker 1: viola if you prefer, we have ourselves a fluorescent light bulb. 526 00:33:06,320 --> 00:33:08,240 Speaker 1: By the way, if you have a black light, you 527 00:33:08,360 --> 00:33:11,680 Speaker 1: essentially have a fluorescent bulb that does not have those 528 00:33:11,680 --> 00:33:15,960 Speaker 1: phosphors necessarily on the inside, because it's just emitting the 529 00:33:16,080 --> 00:33:19,800 Speaker 1: ultra violet light directly. And then you can have those 530 00:33:19,800 --> 00:33:25,520 Speaker 1: wicked uh van posters light up in pretty colors. All 531 00:33:25,560 --> 00:33:29,720 Speaker 1: in all, you're just another brick in the wall, thank you. 532 00:33:30,080 --> 00:33:33,560 Speaker 1: So uh yeah, I mean that's the that's the essential 533 00:33:33,600 --> 00:33:36,480 Speaker 1: way that fluorescence work. And this is also why because 534 00:33:36,520 --> 00:33:43,320 Speaker 1: they contain mercury why they are so dangerous or potentially dangerous, 535 00:33:43,320 --> 00:33:47,080 Speaker 1: because mercury is toxic, and if you were to say, 536 00:33:47,520 --> 00:33:51,440 Speaker 1: I don't know, drop a palette of fluorescent light bulbs 537 00:33:51,480 --> 00:33:55,680 Speaker 1: in a warehouse, you could have a potentially dangerous situation 538 00:33:55,720 --> 00:33:57,880 Speaker 1: on your hands because you could know very much have 539 00:33:58,000 --> 00:34:03,720 Speaker 1: enough mercury there to suffer mercury poisoning. Yeah, it's um. 540 00:34:03,760 --> 00:34:07,480 Speaker 1: It's in a way sort of amusing that so many 541 00:34:07,520 --> 00:34:12,799 Speaker 1: of my friends remember busting fluorescent lightbulbs uh fondly because 542 00:34:12,800 --> 00:34:15,560 Speaker 1: they make out, they make a loud noise. I had one. 543 00:34:16,600 --> 00:34:19,359 Speaker 1: I was in a bookstore once when uh, and I 544 00:34:19,400 --> 00:34:22,800 Speaker 1: was just perusing some books, so I'm very much focused 545 00:34:22,800 --> 00:34:25,960 Speaker 1: on what I'm doing when the employee behind me, who 546 00:34:26,080 --> 00:34:30,000 Speaker 1: was trying to change out a fluorescent bulb, accidentally dropped 547 00:34:30,000 --> 00:34:33,480 Speaker 1: the one in her hands from a ladder and it 548 00:34:33,640 --> 00:34:35,840 Speaker 1: landed directly behind me. And I thought I had just 549 00:34:35,880 --> 00:34:39,640 Speaker 1: been hit by a shotgun. Okay, turned out I wasn't 550 00:34:40,160 --> 00:34:44,080 Speaker 1: well and and and at that time, it wasn't uh 551 00:34:44,280 --> 00:34:48,240 Speaker 1: popular knowledge. I probably shouldn't say common knowledge, but popular knowledge. 552 00:34:48,280 --> 00:34:52,120 Speaker 1: People just didn't know, uh, that there was mercury in there. Now, 553 00:34:52,120 --> 00:34:55,200 Speaker 1: I mean, admittedly there's not a boatload of mercury in there, 554 00:34:55,239 --> 00:34:58,520 Speaker 1: but you know, it could it could be something serious. 555 00:34:59,080 --> 00:35:02,319 Speaker 1: And that's why in your fluorescent light spurned out, it's 556 00:35:02,400 --> 00:35:04,880 Speaker 1: a good idea to find someone who can take it 557 00:35:04,920 --> 00:35:08,239 Speaker 1: and recycle that, not only for safety reasons, but also 558 00:35:08,280 --> 00:35:10,959 Speaker 1: because you know they can recover some of that material. Now, 559 00:35:12,080 --> 00:35:16,080 Speaker 1: when you're talking about the fluorescent light tubes, UH, that's 560 00:35:16,080 --> 00:35:18,440 Speaker 1: pretty much it. I mean you've got the uh, the 561 00:35:18,480 --> 00:35:20,440 Speaker 1: tube of gas with the caps on the end, and 562 00:35:20,480 --> 00:35:24,440 Speaker 1: you plug it into the uh the light fixture to 563 00:35:24,840 --> 00:35:28,719 Speaker 1: have it work. Well, there's there's other stuff underneath that 564 00:35:29,239 --> 00:35:31,279 Speaker 1: that you may not necessarily see. It's it's covered up 565 00:35:31,280 --> 00:35:34,719 Speaker 1: by the fixture. UM. One of the most important parts, 566 00:35:34,760 --> 00:35:37,319 Speaker 1: I would argue is the ballast, which is a type 567 00:35:37,320 --> 00:35:43,600 Speaker 1: of transformer UM that basically ups the electricity to make 568 00:35:43,640 --> 00:35:46,520 Speaker 1: it work better with the fluorescent light, because again, you 569 00:35:46,560 --> 00:35:49,399 Speaker 1: have to introduce those ions, which is not necessarily easy 570 00:35:49,480 --> 00:35:51,879 Speaker 1: to do, especially since you've gotten a neert gas in there. 571 00:35:52,440 --> 00:35:54,880 Speaker 1: We're gonna take another quick break here in a second, 572 00:35:55,120 --> 00:35:57,239 Speaker 1: and then after we come back, Chris and I will 573 00:35:57,239 --> 00:36:08,839 Speaker 1: shine a little more light on this subject. So if 574 00:36:08,840 --> 00:36:12,759 Speaker 1: you ever looked at a compact fluorescent line or curly bulbs, 575 00:36:12,800 --> 00:36:15,200 Speaker 1: I like to call them UM because I like to 576 00:36:15,239 --> 00:36:19,000 Speaker 1: do that UM and wonder what the heck the big 577 00:36:19,040 --> 00:36:21,720 Speaker 1: honking bases that you have to screw into a regular 578 00:36:21,800 --> 00:36:25,440 Speaker 1: light fixture. That's where the ballast is. The ballast is 579 00:36:25,520 --> 00:36:31,120 Speaker 1: built into the base of that UH, that fixture, UM, 580 00:36:31,120 --> 00:36:33,880 Speaker 1: which is why it may or may not fit into 581 00:36:33,920 --> 00:36:36,320 Speaker 1: that incandescent and that that fixture that you bought that 582 00:36:36,600 --> 00:36:42,120 Speaker 1: would allow you to use a UM a typical incandescent bulb. 583 00:36:42,360 --> 00:36:44,880 Speaker 1: Now they say in some cases that you should not 584 00:36:45,040 --> 00:36:47,680 Speaker 1: use those because they do generate heat and that can 585 00:36:48,200 --> 00:36:52,320 Speaker 1: uh make the ballast overheat, uh, cause a short circuit 586 00:36:52,480 --> 00:36:55,600 Speaker 1: and possibly fire. You know, it depends on what kind 587 00:36:55,600 --> 00:36:57,160 Speaker 1: of fixture you have, so keep an eye on that. 588 00:36:57,360 --> 00:37:01,200 Speaker 1: But if you've wondered what that what that situation is, um, 589 00:37:01,239 --> 00:37:03,279 Speaker 1: it's built into the ballast, and the ballast is also 590 00:37:03,320 --> 00:37:05,799 Speaker 1: in that case what controls the three way There are 591 00:37:05,840 --> 00:37:09,480 Speaker 1: some three way fluorescent compact fluorescent whites. Um. The ballast 592 00:37:09,680 --> 00:37:15,600 Speaker 1: is what makes that possible because it can control the 593 00:37:15,640 --> 00:37:19,040 Speaker 1: amount of electricity going into the tube. Yeah, it's also 594 00:37:19,080 --> 00:37:23,120 Speaker 1: important to point out that another big difference between using 595 00:37:23,400 --> 00:37:27,120 Speaker 1: free electrons moving through a gas. Essentially you're talking about 596 00:37:27,120 --> 00:37:31,319 Speaker 1: ionized gas or plasma. But I know if you're using 597 00:37:31,320 --> 00:37:35,040 Speaker 1: free electrons moving through a gas, it does behave differently 598 00:37:35,080 --> 00:37:39,359 Speaker 1: than it would if those electrons were moving through a wire. Uh. 599 00:37:39,400 --> 00:37:42,440 Speaker 1: Now with a wire, you know you have the resistance 600 00:37:42,520 --> 00:37:47,080 Speaker 1: is dependent upon the composition and the size of the wire. 601 00:37:47,960 --> 00:37:51,640 Speaker 1: In a in gas discharge, which is in the terms 602 00:37:51,640 --> 00:37:56,440 Speaker 1: of this not something that's gross is uh, it's the 603 00:37:56,520 --> 00:38:01,600 Speaker 1: resistance actually decreases due to current. So when you've got 604 00:38:01,600 --> 00:38:04,680 Speaker 1: a current going, the resistance begins to decrease through this 605 00:38:04,760 --> 00:38:07,719 Speaker 1: gas that's more electrons and ions start to flow through. 606 00:38:08,400 --> 00:38:11,160 Speaker 1: They bump into more atoms, free up more electrons, creates 607 00:38:11,160 --> 00:38:16,160 Speaker 1: more charged particles. So the resistance is UH is constantly 608 00:38:16,520 --> 00:38:19,480 Speaker 1: decreasing as long as that currents on, and that can 609 00:38:19,520 --> 00:38:23,040 Speaker 1: be a problem. If that continues for too long, it'll 610 00:38:23,080 --> 00:38:28,200 Speaker 1: blow out the electrical components of the the the entire system. 611 00:38:28,239 --> 00:38:31,040 Speaker 1: So that's another reason why these ballasts are important. They 612 00:38:31,080 --> 00:38:35,680 Speaker 1: are little safety features that control that so that the 613 00:38:36,480 --> 00:38:41,799 Speaker 1: current doesn't continue indefinitely. It stops briefly, but not so 614 00:38:41,880 --> 00:38:46,279 Speaker 1: briefly as to make the lightbulb turn off, or at 615 00:38:46,360 --> 00:38:47,960 Speaker 1: least if it's turning off, it's turning off at a 616 00:38:48,040 --> 00:38:51,839 Speaker 1: rate so fast that we can't really detect it. Uh. 617 00:38:51,880 --> 00:38:55,080 Speaker 1: You may have noticed, you know, lightbulbs that for us, 618 00:38:55,080 --> 00:38:57,799 Speaker 1: and bulbs that flicker like even when they're on, they're 619 00:38:57,880 --> 00:39:01,160 Speaker 1: just they're just flickering. And that's only speaking. That's the 620 00:39:01,160 --> 00:39:04,799 Speaker 1: ballast that is trying to control this. And you're talking 621 00:39:04,840 --> 00:39:08,120 Speaker 1: about alternating currents, the currents running essentially one way and 622 00:39:08,120 --> 00:39:10,600 Speaker 1: then another way, so it's doing it, you know, and 623 00:39:11,160 --> 00:39:16,280 Speaker 1: the ballast is working for both directions of current and UH, 624 00:39:16,280 --> 00:39:19,120 Speaker 1: and some of the older bulbs the system was not 625 00:39:20,680 --> 00:39:23,680 Speaker 1: controlled very well, like they might have used a magnetic ballast, 626 00:39:24,480 --> 00:39:28,239 Speaker 1: which has a slightly slower reaction time than current ballasts 627 00:39:28,280 --> 00:39:32,560 Speaker 1: that are UH that are usually based on circuitry. So 628 00:39:33,040 --> 00:39:35,000 Speaker 1: those older ballasts, you know, it meant that if you 629 00:39:35,239 --> 00:39:38,120 Speaker 1: had a fluorescent bulb turned on, it might give you 630 00:39:38,160 --> 00:39:41,000 Speaker 1: that flickering look and you might feel like your workplace 631 00:39:41,080 --> 00:39:43,919 Speaker 1: is the same one that was in the documentary Joe 632 00:39:44,000 --> 00:39:46,640 Speaker 1: Versus the Volcano, And you think you have a brain cloud. 633 00:39:46,880 --> 00:39:49,400 Speaker 1: That's right, you have a brain cloud. Well, then you 634 00:39:49,440 --> 00:39:53,520 Speaker 1: have to go to this volcano UH and encounter three 635 00:39:53,520 --> 00:39:58,799 Speaker 1: different versions of the same actress. And I was I 636 00:39:58,880 --> 00:40:01,359 Speaker 1: was working on a Joe about how when you were 637 00:40:01,360 --> 00:40:03,320 Speaker 1: flying in your hot air balloon and you needed to 638 00:40:03,360 --> 00:40:06,080 Speaker 1: go higher, you would throw out the fluorescent light fixtures 639 00:40:06,120 --> 00:40:08,840 Speaker 1: because you know the kind of throw the ballast's overboard. 640 00:40:09,160 --> 00:40:12,719 Speaker 1: Ironically enough, that's somewhat true. I've changed a ballast out 641 00:40:12,760 --> 00:40:15,840 Speaker 1: of my fluorescent light fixture in my kitchen and they're heavy, 642 00:40:15,840 --> 00:40:18,720 Speaker 1: are they It's like a brick. Anyway, Well, we should 643 00:40:18,719 --> 00:40:21,279 Speaker 1: probably move on to the third type of light bulb. 644 00:40:21,320 --> 00:40:24,160 Speaker 1: I wanted to talk about the LED. Actually, if you 645 00:40:24,200 --> 00:40:27,239 Speaker 1: look at our artist believe it or not, there's an 646 00:40:27,320 --> 00:40:30,719 Speaker 1: article on how stuff works dot com about light emitting diodes. Yeah, 647 00:40:30,719 --> 00:40:32,640 Speaker 1: we have articles on all of this which made this 648 00:40:32,680 --> 00:40:37,240 Speaker 1: podcast way easy to research. Yes, yes, But the funny 649 00:40:37,280 --> 00:40:39,440 Speaker 1: thing is if you look at the diagram, the the 650 00:40:39,520 --> 00:40:42,160 Speaker 1: cross section that are artists have put together of a 651 00:40:42,239 --> 00:40:44,799 Speaker 1: light emitting diode, it's sort of in a way resembles 652 00:40:45,400 --> 00:40:49,200 Speaker 1: an incandescent light bulb because it is a diode inside 653 00:40:49,200 --> 00:40:52,799 Speaker 1: a casing. Yeah, now in this case, the the light 654 00:40:52,840 --> 00:40:55,960 Speaker 1: of Right, the light emitting diode is a is a 655 00:40:56,000 --> 00:40:59,720 Speaker 1: type of semiconductor. Actually, in a way, it's the simplest 656 00:40:59,719 --> 00:41:02,719 Speaker 1: se conductor. There is a diode in general, not just 657 00:41:02,800 --> 00:41:04,800 Speaker 1: a light emitting diode, but a diode in general is 658 00:41:04,800 --> 00:41:09,600 Speaker 1: a semiconductor, and it conducts electricity, but not as completely 659 00:41:09,640 --> 00:41:12,719 Speaker 1: as it could. Right. Essentially, it's a semiconductor. It has 660 00:41:12,760 --> 00:41:16,680 Speaker 1: a varying ability to conduct electricity, so sometimes it connect 661 00:41:16,719 --> 00:41:19,680 Speaker 1: like an insulator, sometimes as a conductor. It all depends 662 00:41:19,719 --> 00:41:25,200 Speaker 1: on this stuff. Generally speaking, control what what you have 663 00:41:25,320 --> 00:41:29,000 Speaker 1: is you've got a semiconductor with two different types of material, 664 00:41:29,120 --> 00:41:30,640 Speaker 1: and it tends to we tend to call it N 665 00:41:30,760 --> 00:41:34,320 Speaker 1: type material and P type material. So the N type 666 00:41:34,320 --> 00:41:40,680 Speaker 1: material has extra negatively charged particles, so it has a 667 00:41:40,680 --> 00:41:44,560 Speaker 1: negative charge overall. Then the P type material, I think 668 00:41:44,600 --> 00:41:47,680 Speaker 1: you can see where this is going, has extra positively 669 00:41:47,800 --> 00:41:53,640 Speaker 1: charged particles. Yes I'm positive, not just sure, I'm positive. 670 00:41:54,480 --> 00:41:57,799 Speaker 1: So you can think of the N type material as 671 00:41:57,840 --> 00:42:01,920 Speaker 1: having an excess of electrons. The P type material has 672 00:42:01,960 --> 00:42:05,319 Speaker 1: what we call holes. These are places where the electrons 673 00:42:05,480 --> 00:42:09,000 Speaker 1: could go. Now, electrons definitely want to get over to 674 00:42:09,040 --> 00:42:12,439 Speaker 1: the positively charged holes. They want to move to those 675 00:42:12,440 --> 00:42:15,880 Speaker 1: holes because, as we know, when you're talking about charges, 676 00:42:16,239 --> 00:42:22,439 Speaker 1: opposites tracked. John Marsha, Yes, in in subatomic particle form. 677 00:42:22,880 --> 00:42:26,600 Speaker 1: So you've got the negative and the positive materials and 678 00:42:26,640 --> 00:42:29,440 Speaker 1: they're kind of smushed together in a in a diode. 679 00:42:29,840 --> 00:42:32,880 Speaker 1: So you've you've bond together the IN type material to 680 00:42:33,080 --> 00:42:36,120 Speaker 1: the P type material. So you've got the the negatively 681 00:42:36,200 --> 00:42:39,279 Speaker 1: charged and the positively charged m botted together. And there's 682 00:42:39,280 --> 00:42:42,720 Speaker 1: an electrode attached to each end. So the N type 683 00:42:42,719 --> 00:42:46,000 Speaker 1: has an electrode attached, the P type has an electrode attached. Now, 684 00:42:46,760 --> 00:42:50,640 Speaker 1: if you don't apply any voltage across this diode. The 685 00:42:50,719 --> 00:42:53,680 Speaker 1: electrons from the N type material fill up the holes 686 00:42:53,719 --> 00:42:57,000 Speaker 1: in the P type material, and it creates what is 687 00:42:57,040 --> 00:43:01,480 Speaker 1: called a depletion zone. And in the depletion zone, the 688 00:43:01,560 --> 00:43:05,680 Speaker 1: semiconductor becomes an insulator. You know, you've you've got those 689 00:43:05,719 --> 00:43:08,640 Speaker 1: extra electrons, have filled up the holes that were on 690 00:43:08,680 --> 00:43:11,880 Speaker 1: the positively charge side, and you've reached sort of a 691 00:43:11,960 --> 00:43:16,480 Speaker 1: neutral ground, right, So depletion zone is that neutral ground. 692 00:43:17,200 --> 00:43:20,600 Speaker 1: There are no free electrons or empty spaces, so it's 693 00:43:20,680 --> 00:43:23,640 Speaker 1: just kind of there. But if you want to get 694 00:43:23,680 --> 00:43:26,640 Speaker 1: rid of that depletion zone, then you need to push 695 00:43:26,680 --> 00:43:31,040 Speaker 1: electrons across, moving from the N type area towards the 696 00:43:31,040 --> 00:43:34,719 Speaker 1: P type area. And then h to do that, you 697 00:43:34,840 --> 00:43:38,000 Speaker 1: just connect the the IN type side of the diode 698 00:43:38,040 --> 00:43:40,600 Speaker 1: to the negative end of a circuit, P type side 699 00:43:40,640 --> 00:43:43,160 Speaker 1: to the positive end, and the free electrons and the 700 00:43:43,200 --> 00:43:45,680 Speaker 1: N type material are repelled by the negative side because 701 00:43:45,719 --> 00:43:49,239 Speaker 1: again you know, like charge repels like yes, they're drawn 702 00:43:49,280 --> 00:43:53,360 Speaker 1: to the positive end, and you then complete the circuit 703 00:43:53,480 --> 00:43:56,920 Speaker 1: and you get this um you get this electron movement. 704 00:43:57,320 --> 00:43:59,080 Speaker 1: If you try to go the other way, it wouldn't 705 00:43:59,120 --> 00:44:03,360 Speaker 1: work because the negatively charged particles going into the positive 706 00:44:03,440 --> 00:44:05,000 Speaker 1: end would just fill up the holes and then it 707 00:44:05,040 --> 00:44:08,520 Speaker 1: would stop. So a diode is kind of like a 708 00:44:08,560 --> 00:44:11,480 Speaker 1: one way street and electronics, if you hook up a 709 00:44:11,520 --> 00:44:15,440 Speaker 1: diode U current can only flow in one direction and 710 00:44:15,480 --> 00:44:17,200 Speaker 1: it will not flow the other way. So if you 711 00:44:17,280 --> 00:44:21,560 Speaker 1: even if you reversed the current, it would not complete 712 00:44:21,560 --> 00:44:25,759 Speaker 1: the circuit if it went against the diode. Reversing the 713 00:44:25,800 --> 00:44:34,480 Speaker 1: polarity just won't work, Captain. So that's your basic led. 714 00:44:34,760 --> 00:44:38,960 Speaker 1: But visible light emitting diode are made up of materials 715 00:44:39,040 --> 00:44:43,600 Speaker 1: that create a wide gap between where the hole is 716 00:44:43,640 --> 00:44:46,360 Speaker 1: and where the electrons are so that when the electrons 717 00:44:46,400 --> 00:44:49,399 Speaker 1: move through they do emit they give off photons. Because 718 00:44:49,400 --> 00:44:51,919 Speaker 1: again we're talking about when electrons are moving down through 719 00:44:51,920 --> 00:44:55,000 Speaker 1: the orbitals. Uh you know, you you've given them enough 720 00:44:55,080 --> 00:44:58,040 Speaker 1: energy for them to to move out of their normal orbitals. 721 00:44:58,360 --> 00:45:00,920 Speaker 1: Once they move down, they get off light. Well, the 722 00:45:01,040 --> 00:45:04,200 Speaker 1: greater that gap is, the more light they give off. 723 00:45:04,960 --> 00:45:09,880 Speaker 1: So if you create a visible light emitting diode and 724 00:45:10,080 --> 00:45:13,360 Speaker 1: you use these materials that create these wider gaps between 725 00:45:13,400 --> 00:45:18,080 Speaker 1: the conduction band and the lower orbitals of the electrons, 726 00:45:18,680 --> 00:45:21,640 Speaker 1: that gap is what allows the electrons to give off 727 00:45:21,880 --> 00:45:24,719 Speaker 1: light and in general, these L E d s tend 728 00:45:24,760 --> 00:45:27,080 Speaker 1: to look if you look at a single LED, they 729 00:45:27,080 --> 00:45:29,719 Speaker 1: tend to look like a miniature light bulb light Christmas saying, 730 00:45:30,520 --> 00:45:33,160 Speaker 1: now there's no filament in there, because again you're just 731 00:45:33,400 --> 00:45:36,319 Speaker 1: what all you're doing is you're allowing those electrons to 732 00:45:36,719 --> 00:45:41,160 Speaker 1: move in those those orbitals, and that's what's giving off 733 00:45:41,160 --> 00:45:43,319 Speaker 1: the photons. And these little light bulbs tend to be 734 00:45:43,320 --> 00:45:46,479 Speaker 1: shaped in such a way that it guides the light 735 00:45:46,560 --> 00:45:49,560 Speaker 1: that's emitted in a very particular direction. So that way 736 00:45:49,600 --> 00:45:52,319 Speaker 1: it's a very concentrated light. Yes, So if you see 737 00:45:52,520 --> 00:45:55,680 Speaker 1: an LED light fixture and this could be you know, 738 00:45:55,920 --> 00:45:59,319 Speaker 1: an LED light bulb or on on the back of cars. 739 00:45:59,360 --> 00:46:02,640 Speaker 1: I've seen a lot of um uh tail lights in 740 00:46:02,719 --> 00:46:05,279 Speaker 1: recent cars that use L E d s, And you 741 00:46:05,320 --> 00:46:07,640 Speaker 1: can tell because it will be a group of them 742 00:46:07,640 --> 00:46:10,480 Speaker 1: together um. And so it looks like there are lots 743 00:46:10,520 --> 00:46:12,960 Speaker 1: of little tiny dots of light in a pattern you know, 744 00:46:13,000 --> 00:46:18,520 Speaker 1: maybe a UM series of concentric circle type things or 745 00:46:18,640 --> 00:46:21,279 Speaker 1: or you know, some other kind of thing um and 746 00:46:21,320 --> 00:46:23,080 Speaker 1: it's you can you can tell that it's an LED 747 00:46:23,200 --> 00:46:26,000 Speaker 1: light specifically because you can see the little dots but 748 00:46:26,080 --> 00:46:28,439 Speaker 1: together when they work together like that, they can be 749 00:46:28,880 --> 00:46:31,080 Speaker 1: very bright. I have a couple of LED flashlights as 750 00:46:31,080 --> 00:46:34,520 Speaker 1: a matter of fact, Um that you know. You's like, 751 00:46:34,520 --> 00:46:38,600 Speaker 1: hey does this thing work? Oh? You know, Um, however 752 00:46:38,760 --> 00:46:41,239 Speaker 1: they're very efficient. Yes, yes, I've got a couple of 753 00:46:41,320 --> 00:46:43,799 Speaker 1: LED lights in my house. Actually, there are a couple 754 00:46:43,800 --> 00:46:46,200 Speaker 1: of light fixtures that were specifically designed to work with 755 00:46:46,320 --> 00:46:52,000 Speaker 1: LED lights. And yes, they are incredibly efficient, particularly compared 756 00:46:52,040 --> 00:46:55,040 Speaker 1: to incandescence and even fluorescence. But we didn't really mention 757 00:46:55,080 --> 00:46:58,319 Speaker 1: it before. Escent lights are more efficient than incandescent light bulbs. Yes, 758 00:46:58,480 --> 00:47:01,680 Speaker 1: they last longer, they use less energy to create light. 759 00:47:01,719 --> 00:47:05,400 Speaker 1: They don't They don't lose as much energy in producing heat. 760 00:47:06,280 --> 00:47:09,880 Speaker 1: So yeah, so they don't heat up as hot as 761 00:47:09,880 --> 00:47:12,359 Speaker 1: an incandescent bulb. That's not saying that a florescent bulb 762 00:47:12,440 --> 00:47:15,000 Speaker 1: is going to be cool to the touch. It's just 763 00:47:15,080 --> 00:47:17,320 Speaker 1: not going to be as hot as an incandescent bulb. 764 00:47:17,440 --> 00:47:21,040 Speaker 1: Is l E ED is even more efficient. Uh, it 765 00:47:21,160 --> 00:47:25,759 Speaker 1: has a much higher luminous efficacy, if you will. As 766 00:47:25,760 --> 00:47:27,440 Speaker 1: we say in our article on L E D s, 767 00:47:27,520 --> 00:47:31,200 Speaker 1: what's your language? I'm sorry, um, but they talked about 768 00:47:31,239 --> 00:47:34,759 Speaker 1: how in our article they mentioned a specific type of 769 00:47:34,920 --> 00:47:37,080 Speaker 1: LED light bulb in this case, it was this Sewel's 770 00:47:37,600 --> 00:47:42,040 Speaker 1: Evo lux LED bulb, which produces seventy six point nine 771 00:47:42,200 --> 00:47:45,680 Speaker 1: lumens per what, which is essentially how bright. This is 772 00:47:46,080 --> 00:47:49,040 Speaker 1: dependent upon how much energy you're putting into it, whereas 773 00:47:49,040 --> 00:47:53,560 Speaker 1: an incandescent bulb is seventeen lumens per what. So seventy 774 00:47:53,560 --> 00:47:58,160 Speaker 1: six point nine versus seventeen it shows that the efficiency 775 00:47:58,480 --> 00:48:00,600 Speaker 1: of the l e ED is far greater than that 776 00:48:00,640 --> 00:48:05,040 Speaker 1: of the incandescent bulb, and the LED lifetime can be 777 00:48:05,120 --> 00:48:10,800 Speaker 1: around fifty thousand hours, So compare that to a couple 778 00:48:10,800 --> 00:48:15,520 Speaker 1: of thousand hours for a typical incandescent bulb, and that's 779 00:48:15,560 --> 00:48:19,080 Speaker 1: a big difference. Now, LED light bulbs do tend to 780 00:48:19,120 --> 00:48:23,960 Speaker 1: be much more expensive than incandescent or fluorescent bulbs. However, 781 00:48:24,400 --> 00:48:27,360 Speaker 1: if you measure that across the lifetime of the bulb 782 00:48:27,400 --> 00:48:31,319 Speaker 1: and you factor in things like energy savings, uh, they 783 00:48:31,560 --> 00:48:34,960 Speaker 1: on the long term can be a good investment. However, 784 00:48:35,040 --> 00:48:37,680 Speaker 1: the upfront cost is still much higher, so that can 785 00:48:37,719 --> 00:48:40,319 Speaker 1: be a barrier for a lot of people. The cost 786 00:48:40,360 --> 00:48:44,800 Speaker 1: has been decreasing UH quite a bit since over the 787 00:48:44,880 --> 00:48:49,240 Speaker 1: last decade or so, since semiconductor material has become much 788 00:48:49,320 --> 00:48:53,359 Speaker 1: more cost effective. Is when these first came out, semiconductor 789 00:48:53,440 --> 00:48:57,120 Speaker 1: material was a precious commodity. It was not something that 790 00:48:57,160 --> 00:48:59,279 Speaker 1: was mass produced. It was not something that you could 791 00:48:59,280 --> 00:49:01,040 Speaker 1: easily get your hand ends on, and so it was 792 00:49:01,200 --> 00:49:05,240 Speaker 1: much more expensive. But just as Gordon More predicted way 793 00:49:05,320 --> 00:49:09,279 Speaker 1: back in the sixties, the manufacturing processes would mean that 794 00:49:09,520 --> 00:49:12,600 Speaker 1: costs would come down, efficiencies go up, and as a result, 795 00:49:12,960 --> 00:49:15,120 Speaker 1: we're able to get more efficient products. Now he was 796 00:49:15,160 --> 00:49:18,120 Speaker 1: talking specifically about integrated circuits, but as it turns out, 797 00:49:18,200 --> 00:49:22,480 Speaker 1: that kind of applies to lots of stuff. Doesn't necessarily 798 00:49:22,480 --> 00:49:24,120 Speaker 1: mean that the light bulbs will have next year will 799 00:49:24,120 --> 00:49:25,919 Speaker 1: be twice as bright as the ones we have this year. 800 00:49:26,239 --> 00:49:30,200 Speaker 1: So the analogy doesn't continue all the way there, but 801 00:49:30,280 --> 00:49:35,480 Speaker 1: it's still I think, semi applicable. So yeah, you can 802 00:49:36,239 --> 00:49:40,759 Speaker 1: see the differences between these these approaches. Uh, Ultimately, it's 803 00:49:40,800 --> 00:49:44,800 Speaker 1: all about again exciting atoms, and once those aboms get excited, 804 00:49:45,040 --> 00:49:47,880 Speaker 1: they just light up. I hope you guys enjoyed that 805 00:49:47,960 --> 00:49:51,920 Speaker 1: classic episode of tech stuff. I really liked when we 806 00:49:51,960 --> 00:49:53,920 Speaker 1: got to do the history ones where we got to 807 00:49:54,040 --> 00:49:58,920 Speaker 1: really dive into what actually happened, because frequently the stories 808 00:49:58,960 --> 00:50:03,680 Speaker 1: that we learn in history books are the fast, simple, 809 00:50:03,840 --> 00:50:07,920 Speaker 1: easy explanations, because as we really begin to understand the 810 00:50:07,920 --> 00:50:12,480 Speaker 1: more we look into technology, development of new technologies is 811 00:50:12,600 --> 00:50:17,800 Speaker 1: often very complicated, with lots of different people making contributions 812 00:50:18,320 --> 00:50:22,520 Speaker 1: that ultimately will result in a new technology kind of 813 00:50:22,560 --> 00:50:26,239 Speaker 1: coming to be. But it's rarely so simple as to 814 00:50:26,320 --> 00:50:29,359 Speaker 1: point to a single person and say, that person right 815 00:50:29,400 --> 00:50:32,320 Speaker 1: there did it. Yo. If you guys have suggestions for 816 00:50:32,360 --> 00:50:34,920 Speaker 1: our future episodes of tech Stuff, reach out to me, 817 00:50:35,239 --> 00:50:38,439 Speaker 1: send me a message on tech stuff at how stuff 818 00:50:38,480 --> 00:50:41,120 Speaker 1: works dot com, or pop on over to our website 819 00:50:41,120 --> 00:50:44,600 Speaker 1: that's tech stuff podcast dot com. They're going to find 820 00:50:44,600 --> 00:50:47,000 Speaker 1: an archive of all of our past episodes. You'll find 821 00:50:47,040 --> 00:50:50,480 Speaker 1: links to our social media accounts, and you will also 822 00:50:50,560 --> 00:50:52,960 Speaker 1: find a link to our online store, where every purchase 823 00:50:53,040 --> 00:50:56,200 Speaker 1: you make goes to help the show. We greatly appreciate it. Now, 824 00:50:56,200 --> 00:51:03,840 Speaker 1: I'll talk to you again really soon. M Text Stuff 825 00:51:03,880 --> 00:51:06,240 Speaker 1: is a production of I Heart Radio's How Stuff Works. 826 00:51:06,400 --> 00:51:09,200 Speaker 1: For more podcasts from I heart Radio, visit the i 827 00:51:09,320 --> 00:51:12,560 Speaker 1: heart Radio app, Apple Podcasts, or wherever you listen to 828 00:51:12,600 --> 00:51:13,520 Speaker 1: your favorite shows.