WEBVTT - TechStuff Classic: TechStuff Gets a Bright Idea 0:00:04.240 --> 0:00:07.240 Welcome to tex Stuff, a production of I Heart Radios, 0:00:07.320 --> 0:00:14.240 How Stuff Works. Hey there, in Welcome to tech Stuff. 0:00:14.320 --> 0:00:17.720 I'm your host, Jonathan Strickland. I'm an executive producer with 0:00:17.840 --> 0:00:20.320 How Stuff Works and I heart Radio and a love 0:00:20.320 --> 0:00:22.720 of all things tech, and it is time for a 0:00:22.800 --> 0:00:26.599 classic episode of tech Stuff. This episode is one I 0:00:26.720 --> 0:00:30.520 referenced in a very recent episode of tech Stuff. In fact, 0:00:30.560 --> 0:00:32.519 it maybe so recent that I don't know if it's 0:00:32.520 --> 0:00:35.960 published yet or not. It's called tex Stuff Gets a 0:00:36.040 --> 0:00:40.919 Bright Idea, and it's all about the real history of 0:00:40.960 --> 0:00:44.120 the light bulb. We often hear that Thomas Edison invented 0:00:44.120 --> 0:00:47.000 the light bulb, but did he for real z s though? 0:00:47.680 --> 0:00:51.640 We find out in this episode. Hey there, I just 0:00:51.680 --> 0:00:55.000 looked up and there he was doing that thing, getting 0:00:55.040 --> 0:00:57.520 my get my energy up. Actually, one of the things 0:00:57.560 --> 0:01:01.040 that uh, you know, we start the episode of pretty traditionally, 0:01:01.120 --> 0:01:03.520 one of the things that we had as an early 0:01:03.720 --> 0:01:06.360 ritual as we recorded Tech Stuff was Jonathan and I 0:01:06.360 --> 0:01:09.640 would be sitting here in the virtual darkness and someone 0:01:10.400 --> 0:01:12.800 we had different engineers over the time over the years now, 0:01:12.840 --> 0:01:15.319 but someone would come in and turn on the lights, yes, 0:01:15.400 --> 0:01:22.039 and usually lighted begs, but we wanted to talk a 0:01:22.040 --> 0:01:26.039 little bit about light, specifically light bulbs today. So what 0:01:26.160 --> 0:01:29.120 a brilliant idea of those were? You know before lightbulbs, 0:01:29.840 --> 0:01:32.480 Before light bulbs, there was no way to indicate that 0:01:32.520 --> 0:01:37.959 you had an idea. Yeah, yeah, there's no there's no yeah, 0:01:38.520 --> 0:01:41.559 pre light bulb there was no ting. Before we get 0:01:41.640 --> 0:01:45.480 into how lightbulbs work in their history and everything, I 0:01:45.480 --> 0:01:48.200 want to lay down a little physics for you. All right, 0:01:48.280 --> 0:01:52.560 go ahead and enlighten us. See what you did much? 0:01:52.640 --> 0:01:56.280 So we are talking about light and what is light? Well, 0:01:56.360 --> 0:01:59.880 light is made up of these very tiny part of 0:02:00.000 --> 0:02:07.000 all like packets called photons. They've got energy, they have momentum, 0:02:07.040 --> 0:02:10.800 but there's one thing they do not have charge accounts 0:02:11.040 --> 0:02:16.120 mass or I was going they have no mass, but 0:02:16.240 --> 0:02:20.960 not no moss. Photons are these packets of energy. They 0:02:21.000 --> 0:02:24.840 have momentum but not mass. And these particles, these these 0:02:24.880 --> 0:02:31.200 photons are emitted by atoms. Once you have excited an 0:02:31.240 --> 0:02:34.560 atom to the point where it's electron starts to move 0:02:34.639 --> 0:02:39.480 out of its normal orbit and goes into a further 0:02:39.639 --> 0:02:43.560 orbit from the atoms nucleus. And once once you remove 0:02:43.639 --> 0:02:47.280 the energy source from that atom, the electron will eventually 0:02:47.320 --> 0:02:50.880 return to its normal orbit around the nucleus. But it 0:02:50.960 --> 0:02:55.000 has to it has to get rid of that energy 0:02:55.080 --> 0:02:58.440 that you have pushed into it. Right, energy is not 0:02:58.480 --> 0:03:02.840 created or destroyed, it's just transferred. So this electron, as 0:03:02.840 --> 0:03:05.200 it's coming back down to its normal orbital is going 0:03:05.240 --> 0:03:08.800 to shed off energy. And in this case, the energy 0:03:08.880 --> 0:03:13.480 is in the form of photons. Now, photons are going 0:03:13.520 --> 0:03:17.959 to be emitted in the entire spectrum of light. Now, humans, 0:03:18.440 --> 0:03:22.160 we are capable of perceiving a narrow band of that 0:03:22.280 --> 0:03:28.480 spectrum called the visible spectrum because it's visible to us. Oh, 0:03:28.600 --> 0:03:30.480 I always wondered about that. This is where the whole 0:03:30.560 --> 0:03:33.639 roy G BIV thing comes in. Right. The different wavelengths 0:03:33.639 --> 0:03:38.160 of light dictate what the color is as we perceive it. Uh. 0:03:38.200 --> 0:03:41.720 The but the the light goes well beyond outside the 0:03:41.720 --> 0:03:44.720 the visible range. There's things like ultra violet and infrared, 0:03:44.800 --> 0:03:48.200 and then you get into electromagnetic radiation as you go 0:03:48.360 --> 0:03:52.680 further out. But and anyway, Uh, these photons can come 0:03:52.680 --> 0:03:58.360 into various forms, so you can have of infrared photon 0:03:58.600 --> 0:04:01.960 or ultra violet photons. So, uh, if it's in the 0:04:02.000 --> 0:04:04.520 visible light spectrum, we're able to see it. Now that's 0:04:04.560 --> 0:04:10.080 important because that's the whole basis of creating a light bulb, 0:04:10.120 --> 0:04:12.840 as you want to create some sort of device that 0:04:13.400 --> 0:04:18.120 you can use to create photons so that you can 0:04:18.160 --> 0:04:22.080 illuminate an area, and before light bulbs, you didn't really 0:04:22.120 --> 0:04:24.960 have that option unless you set something on fire. Uh, 0:04:24.960 --> 0:04:26.920 And there's a limited number of things we can set 0:04:26.920 --> 0:04:29.840 on fire before we set ourselves on fire or we 0:04:29.960 --> 0:04:32.800 run out of stuff that is flammable. So it was 0:04:32.839 --> 0:04:35.080 a good idea to try and develop something that could 0:04:35.520 --> 0:04:41.000 create light in another way. Now, Uh, how do we 0:04:41.040 --> 0:04:44.880 know about how what is the principle upon which light 0:04:44.880 --> 0:04:50.120 bulbs work. Well, again, if you excite an atom and 0:04:50.279 --> 0:04:53.240 you push those electrons out, when the electrons come back in, 0:04:53.320 --> 0:04:58.520 they emit photons. If you give enough energy to an object, 0:04:59.120 --> 0:05:02.599 then you can it enough uh photons for it to 0:05:02.640 --> 0:05:05.320 be within the depending upon the nature of that material, 0:05:05.480 --> 0:05:08.400 for it to be within the visible spectrum for it 0:05:08.440 --> 0:05:12.360 to be perceptible. Because even if it's in the visible spectrum, 0:05:12.440 --> 0:05:15.719 if the energy is not great enough, you won't be 0:05:15.760 --> 0:05:19.200 able to see it. And we're all emitting energy all 0:05:19.240 --> 0:05:22.680 the time, like humans are emitting infrared energy all the time, 0:05:22.720 --> 0:05:24.320 and if you had an infrared camera, you would be 0:05:24.320 --> 0:05:26.839 able to see it even in a perfectly dark room. 0:05:27.000 --> 0:05:29.200 You look at the infrared camera, look at a person, 0:05:29.520 --> 0:05:32.680 you would see light as interpreted by the sensor in 0:05:32.720 --> 0:05:35.679 that camera and converted to visible light for us to see. 0:05:35.839 --> 0:05:37.840 You would be able to see that person because they're 0:05:37.839 --> 0:05:42.240 emitting that infrared light. Well, we may even depending on 0:05:42.440 --> 0:05:45.159 what what, depending on the material, it may even be 0:05:45.279 --> 0:05:47.840 emitting visible light, but it might be emitting at at 0:05:47.920 --> 0:05:51.520 levels so low as to be imperceptible to humans. So 0:05:51.560 --> 0:05:54.200 if you add more energy, you can boost that and 0:05:54.240 --> 0:05:58.560 actually see the visible light. Uh. And this can happen 0:05:58.640 --> 0:06:01.720 with things like soled materials. And there was a fellow 0:06:02.440 --> 0:06:09.159 named John William Draper who in seven demonstrated that solid materials, 0:06:09.200 --> 0:06:12.839 almost all of them, will glow once they reach a 0:06:12.880 --> 0:06:19.760 temperature of seven kelvin. Kelvin's a scientific scale for temperatures. 0:06:20.320 --> 0:06:22.919 Kelvin is what we have when you get to zero 0:06:23.000 --> 0:06:26.680 kelvin that says that's as cold as you can get. 0:06:26.720 --> 0:06:30.080 It actually refers to molecular movement, and at zero kelvin, 0:06:30.120 --> 0:06:35.280 there is no molecular movement. So that's like the deepest 0:06:35.360 --> 0:06:40.760 depths of space. Where there's nothing absolutely absolutely uh So, 0:06:40.880 --> 0:06:43.400 if you wanted to convert that into degrees that we're 0:06:43.440 --> 0:06:46.440 more familiar with most of us anyway, it would be 0:06:46.440 --> 0:06:50.000 about five and twenty five degrees celsius or nine seventy 0:06:50.040 --> 0:06:54.560 seven degrees fahrenheit. And at that temperature, solid materials will 0:06:54.560 --> 0:06:58.200 start to glow. We call it the draper point. Now, 0:06:58.520 --> 0:07:02.920 in order to have a object glow at a uh 0:07:02.960 --> 0:07:06.040 at a at an intensity bright enough for it to illuminate, say, 0:07:06.080 --> 0:07:09.160 a room, you will have to put in more energy 0:07:09.240 --> 0:07:12.480 than that, right, because this is talking about they start 0:07:12.520 --> 0:07:14.160 to glow, but that doesn't mean that they're glowing so 0:07:14.240 --> 0:07:16.920 brightly as to illuminate an entire room. That's where it starts. 0:07:17.640 --> 0:07:19.840 So but you know, you've you've probably seen this. If 0:07:19.880 --> 0:07:23.000 you've ever seen a blacksmith work, then you know the 0:07:23.000 --> 0:07:25.160 blacksmith might be heating up iron and when they take 0:07:25.200 --> 0:07:30.160 that out it's glowing red. Or a glass blower or lava. 0:07:30.480 --> 0:07:33.960 You know, there's lots of stuff that tends to lava. 0:07:34.280 --> 0:07:37.119 It's not all man made, but there's lots of stuff 0:07:37.120 --> 0:07:41.960 out there that um that that demonstrates this. So that's 0:07:42.000 --> 0:07:46.440 the principle. But but the idea behind an electric light 0:07:46.560 --> 0:07:52.640 source actually predates Draper's discovery. Really, yes, back in well 0:07:52.880 --> 0:07:56.280 the early eighteen hundreds. I've seen I've seen reports from 0:07:56.320 --> 0:07:58.560 eighteen o six all the way up to eighteen o nine. 0:07:59.040 --> 0:08:03.560 There's some discrepance's there. But an English chemist and inventor 0:08:03.680 --> 0:08:08.680 named Sir Humphrey Davy, named Humphrey Davy, he was designated 0:08:08.680 --> 0:08:13.440 a night So that's the sir. He connected a battery 0:08:13.800 --> 0:08:17.920 to a strip of charcoal and he used the electricity 0:08:17.960 --> 0:08:20.120 to actually heat up the charcoal to the point where 0:08:20.160 --> 0:08:24.680 it started to glow, which created technically the first electric 0:08:24.800 --> 0:08:31.360 arc lamp. Uh. This was not a viable means of 0:08:31.960 --> 0:08:35.440 illumination as it was hard to do. It required a 0:08:35.440 --> 0:08:37.920 lot of energy. The battery drained really quickly, the carbon 0:08:38.000 --> 0:08:42.000 burned at such a or it got so hot as 0:08:42.000 --> 0:08:47.000 to be incredibly dangerous for uh, say, I don't know 0:08:47.160 --> 0:08:50.680 a typical house. Um. So it was not something that 0:08:50.760 --> 0:08:53.760 was going to immediately be adopted into every household, but 0:08:53.800 --> 0:08:59.680 it was proving a concept. Uh. Also, by the way, 0:08:59.720 --> 0:09:02.480 sir very Davy did go on to invent many things, 0:09:02.480 --> 0:09:06.199 including the Davy lamp, which was not an electrical lamp. 0:09:06.520 --> 0:09:08.720 It was a gas lamp. There was a gas lamp 0:09:08.760 --> 0:09:11.680 that had a mesh screen that would surround the flame, 0:09:12.760 --> 0:09:17.040 so that miners meaning people who mind the earth, not 0:09:17.360 --> 0:09:21.960 people who are underage miners, could take the lamps, although 0:09:22.240 --> 0:09:24.320 depending in England at that point in the time, the 0:09:24.400 --> 0:09:28.120 two may have been the same. Hey, our history has 0:09:28.160 --> 0:09:30.839 not always been a nice one. But the miners could 0:09:30.880 --> 0:09:35.000 take a lamp down below the ground and even if 0:09:35.000 --> 0:09:37.760 they encountered a pocket of gas, the mesh would actually, 0:09:37.920 --> 0:09:41.320 this fine mesh would prevent the gas and the flame 0:09:41.800 --> 0:09:45.800 from making friends and becoming a big boom. Very important 0:09:45.800 --> 0:09:51.360 for miners of both types. So the he did invent that. Again, 0:09:51.440 --> 0:09:53.559 not electrical, but I thought it was an interesting aside. 0:09:53.800 --> 0:10:00.640 Moving ahead back in one Frederick de Moulins, and I'm 0:10:00.679 --> 0:10:05.040 sure I have completely mispronounced his name, and I apologized 0:10:05.080 --> 0:10:09.120 profusely for that. Another Englishman, Yeah it could be. He 0:10:09.200 --> 0:10:12.440 patented a lightbulb in eighteen forty one, and this one 0:10:12.520 --> 0:10:15.280 was comprised of a glass case and a burner or 0:10:15.360 --> 0:10:20.120 burners actually made of carbon and in expensive material you 0:10:20.200 --> 0:10:24.960 may know as platinum. Yeah, you thought that led light 0:10:25.000 --> 0:10:29.280 bulbs were expensive, so uh he he patented that design 0:10:29.640 --> 0:10:34.280 again not really practical for for every day or even 0:10:34.320 --> 0:10:40.120 industrial use. An American inventor named J. W. Starr received 0:10:40.160 --> 0:10:43.240 a patent for a light bulb that used a carbon burner. UM. 0:10:43.280 --> 0:10:47.880 And then the next few decades were spent among inventors 0:10:47.880 --> 0:10:50.960 trying to find a way to perfect the discoveries these 0:10:51.000 --> 0:10:55.000 earlier inventors had found, so that you could create a 0:10:55.640 --> 0:11:00.000 light bulb that made sense, that that was a ficient 0:11:00.559 --> 0:11:02.840 that could light well, that was not going to be 0:11:02.880 --> 0:11:07.600 prohibitively expensive. And there are two names in particular that 0:11:07.640 --> 0:11:11.079 pop up all the time, one of them being probably 0:11:11.160 --> 0:11:14.280 the most famous, uh connected to the light bulb, which 0:11:14.320 --> 0:11:18.120 is Thomas Edison. Yes, it's funny. As we were recording this, 0:11:18.160 --> 0:11:22.960 we are rapidly approaching the hundred thirty third anniversary of 0:11:23.040 --> 0:11:26.959 the first test of Edison's incandescent light bulb. Yeah. Now, 0:11:27.040 --> 0:11:29.560 it is important to note Edison was not the person 0:11:29.640 --> 0:11:31.679 who invented the light bulb. He was not even the 0:11:31.720 --> 0:11:34.480 person to invent the incandescent light bulb, but he was 0:11:35.040 --> 0:11:39.360 someone who perfected that design and made it viable as 0:11:39.400 --> 0:11:43.120 an actual product. Yeah. Now it's it's important to know, 0:11:43.640 --> 0:11:47.840 um that these these early light bulbs. Uh, you know, 0:11:47.920 --> 0:11:51.439 not only were homes not really wired. Actually, the light bulb, 0:11:51.480 --> 0:11:55.800 I would argue, based on my research the over the past, 0:11:55.920 --> 0:11:58.040 you know, the past times that we've done tech stuff. 0:11:58.040 --> 0:12:00.079 We've talked about Edison and Tesla and all these the 0:12:00.160 --> 0:12:03.000 lightbulb actually was sort of the key to getting homes 0:12:03.000 --> 0:12:06.920 wired for electricity. Yeah, I mean you and it made 0:12:06.960 --> 0:12:11.240 sense because suddenly you had households that could be uh 0:12:11.559 --> 0:12:16.880 safely with air quotes around that lit after dark and 0:12:17.160 --> 0:12:22.200 extend the useful uh time human being could get stuff 0:12:22.280 --> 0:12:26.679 done because otherwise, when night fell, we might as well 0:12:26.720 --> 0:12:30.319 just go to bed because it was gonna be pretty dark. Well, 0:12:30.360 --> 0:12:32.679 you know, we're related bed and early to rise, as 0:12:32.720 --> 0:12:35.199 they say, early to bed, early to rise, because otherwise 0:12:35.200 --> 0:12:38.000 you're barking your ship on the coffee table. Well, yeah, 0:12:38.080 --> 0:12:42.120 that's that's true. Well, gas lamps, uh were very very popular. 0:12:43.040 --> 0:12:46.040 But they were I mean, in addition to being obviously 0:12:46.080 --> 0:12:51.360 inherently somewhat dangerous um and oil lamps, but they were 0:12:51.520 --> 0:12:57.320 um smoky, um. They were dirty. So you know, I'm 0:12:57.360 --> 0:13:00.120 sure they probably didn't smell all that great um. But 0:13:00.160 --> 0:13:03.760 the problem with these early lightbulbs is that they weren't 0:13:04.040 --> 0:13:10.920 very practical. Okay, look, I got Yeah. There was another inventor, 0:13:11.040 --> 0:13:14.559 an Englishman, the Englishman named Sir Joseph Swan who was 0:13:14.600 --> 0:13:17.120 working on light bulbs around the same time as Edison, 0:13:17.640 --> 0:13:21.760 and Swan's bulb used carbonized paper as the burner, which 0:13:21.880 --> 0:13:25.200 worked pretty well except that it didn't last terribly long. 0:13:25.720 --> 0:13:28.240 And in fact, this was a problem that a lot 0:13:28.280 --> 0:13:33.080 of lightbulb researchers were encountering that including Edison. The first 0:13:33.080 --> 0:13:36.360 problem was, all right, well, we've we've found uh that 0:13:36.440 --> 0:13:41.120 if you if you run enough electricity through some sort 0:13:41.160 --> 0:13:42.800 of object, you can heat it up enough so that 0:13:42.800 --> 0:13:49.199 it begins to glow. But if that item is exposed 0:13:49.280 --> 0:13:53.319 to oxygen, then it will burn. So even if you 0:13:53.360 --> 0:13:56.439 found a material that does not melt at a high temperature, 0:13:56.679 --> 0:13:58.920 it would burn, It would combust at a high enough 0:13:58.920 --> 0:14:01.920 temperature because it, you know, it would be adjacent to oxygen, 0:14:02.000 --> 0:14:05.959 which you know that that's part of the fuel you need, 0:14:06.080 --> 0:14:08.800 you know, in order to have a fire. UM. So 0:14:09.800 --> 0:14:12.199 the you had to close it off from oxygen, which 0:14:12.240 --> 0:14:14.760 is why there were these these vacuum tubes essentially is 0:14:14.760 --> 0:14:21.680 what they create, these vacuum containers. UM. But Once they 0:14:21.680 --> 0:14:23.520 got through that, they had to find what's the right 0:14:23.560 --> 0:14:27.160 material to use. Actually, what Edison ended up using at 0:14:27.240 --> 0:14:33.960 first was bamboo. He took Japanese bamboo and carbonized it 0:14:34.400 --> 0:14:37.400 and created a filament. And in this case, what a 0:14:37.480 --> 0:14:40.920 filament is is this really long, long, long, long strip 0:14:41.160 --> 0:14:44.840 of material that is then coiled so that you can 0:14:44.960 --> 0:14:50.040 decrease the space that it needs to um to fit 0:14:50.120 --> 0:14:52.600 into whatever you want to put it in. So it's 0:14:52.600 --> 0:14:56.600 got a lot of surface areas. Then the resistance is high. 0:14:56.920 --> 0:15:01.720 A resistance in electricity is the the materials resistance to 0:15:01.800 --> 0:15:04.560 electrons flowing through it freely. The more resistance there is 0:15:04.600 --> 0:15:08.640 in general, okay, you've got greater resistance, you have greater heat. Well, 0:15:08.760 --> 0:15:10.840 the secret to the light here is the amount of 0:15:10.880 --> 0:15:13.760 heat that's being generated. That's the energy that is creating 0:15:13.800 --> 0:15:17.320 this whole system of electrons being pushed out and then 0:15:17.400 --> 0:15:19.360 when they start coming back in, the photons are being 0:15:19.960 --> 0:15:24.480 let out. So let the photons out? Who let the 0:15:24.480 --> 0:15:27.280 photons out? That was as an a swan as it 0:15:27.320 --> 0:15:31.360 turns out. Um. It's interesting because then Edison Edison ended 0:15:31.440 --> 0:15:35.120 up hiring what his first his first light bulb design 0:15:35.280 --> 0:15:39.840 used a temperature controlled switch to try and keep the 0:15:40.080 --> 0:15:43.840 material at the right temperature so that it would the 0:15:43.960 --> 0:15:47.160 light bulb would remain lit longer, because I was an 0:15:47.160 --> 0:15:49.680 early problem with these light bulbs is that their their 0:15:49.800 --> 0:15:52.520 utility was low because they couldn't couldn't burn them for 0:15:52.600 --> 0:15:56.800 very long. But this was a problem because the the 0:15:56.880 --> 0:15:59.840 temperature control controlled switch, once a certain temperature was hit, 0:15:59.880 --> 0:16:03.280 it switch off right the light would go off, And 0:16:03.320 --> 0:16:06.320 so I started creating this flickering problem and made the 0:16:06.360 --> 0:16:11.120 bulb practically unusable. So he then hired a physicist from 0:16:11.120 --> 0:16:17.040 Princeton named Francis Upton, who led Edison's research team working 0:16:17.080 --> 0:16:20.440 on light bulbs, to start practicing with other stuff. That's 0:16:20.440 --> 0:16:22.480 when they came upon the idea of using the bamboo 0:16:22.520 --> 0:16:27.160 as a filament. Um. Swan and Edison ended up battling 0:16:27.160 --> 0:16:31.040 each other. Edison ended up taking patent lawsuits against Swan, 0:16:31.200 --> 0:16:34.480 but then ultimately the two of them formed a partnership 0:16:34.520 --> 0:16:41.880 together and they created the Edison Swan United Company. Teamwork teamwork. Um. Yeah, 0:16:42.200 --> 0:16:44.880 just so, just so you guys know, patent wars are 0:16:44.920 --> 0:16:49.600 not a new thing. Oh no, not in the least. Um. Yeah, 0:16:49.800 --> 0:16:53.440 it's funny. While while carbonized bamboo sounds like an ingredient 0:16:53.560 --> 0:16:58.560 for a hipster sandwich. Um, it did have the ability 0:16:58.600 --> 0:17:03.840 to burn for more than which you know back in 0:17:03.920 --> 0:17:06.159 that time, that was pretty nice for a for a 0:17:06.200 --> 0:17:10.920 light bulb. Yeah, and uh, this served as the basis 0:17:10.960 --> 0:17:14.000 for what future light bulbs would be and then we 0:17:14.400 --> 0:17:16.919 ended up shifting to a different type of filament. But 0:17:16.920 --> 0:17:18.520 we'll get into that in a second. So let's talk 0:17:18.560 --> 0:17:23.680 about the basic anatomy of an incandescent light bulb. And 0:17:23.720 --> 0:17:26.600 don't worry florests and an l e defense. We're going 0:17:26.640 --> 0:17:29.880 to get to you too. You just sit tight. So 0:17:30.240 --> 0:17:35.520 the incandescent bulb, you've got two contacts to two electrical 0:17:35.560 --> 0:17:39.359 context on this on a typical incandescent bulb. One of 0:17:39.400 --> 0:17:41.960 them is at the very end of the bulb, that's 0:17:42.000 --> 0:17:45.439 the base of the bulb, and the other is in 0:17:45.680 --> 0:17:50.920 the actual treads that you screw into your um light 0:17:50.920 --> 0:17:55.200 bulb sucket. Yeah. Actually usually has a squeaky noise which 0:17:55.520 --> 0:17:58.720 has that perfect pitch to give me the heb gbs. 0:17:59.200 --> 0:18:01.119 It's like the finger nae else on the chalkboard type thing. 0:18:01.160 --> 0:18:04.240 It's like almost every single light bulb in my house 0:18:04.320 --> 0:18:09.800 makes that noise. And so it's a physically demanding task 0:18:09.920 --> 0:18:13.240 for me because well, I guess psychologically really more than physically, 0:18:13.760 --> 0:18:17.960 because I I suffer trauma. One follows the other. You 0:18:18.000 --> 0:18:20.320 start to how many how many Jonathans does it take 0:18:20.320 --> 0:18:23.560 to you screw the light bulb? Well, after the first one, 0:18:23.600 --> 0:18:25.960 it takes a few others to calm them down. Yeah, 0:18:26.040 --> 0:18:28.960 I'm not afraid of the dark. I'm just afraid of 0:18:29.040 --> 0:18:31.879 changing light bulbs. So that's not really true. I just 0:18:31.960 --> 0:18:34.800 don't like doing it. But anyway, these metal contacts are 0:18:34.800 --> 0:18:39.600 what create the the circuit, right, so that the circuits 0:18:39.640 --> 0:18:44.240 complete when these two contacts are are in contact with 0:18:44.400 --> 0:18:48.520 the rest of the electrical system. To one um, the 0:18:48.760 --> 0:18:53.000 contacts are attached to some wires and those wires are 0:18:53.000 --> 0:18:57.119 attached to the filament. Now, in this case, the filament 0:18:57.160 --> 0:19:01.520 is no longer bamboo. For your typical incandescent, it's usually tungsten. 0:19:02.160 --> 0:19:05.399 And the reason why it's tungsten is a couple of 0:19:05.440 --> 0:19:08.560 different reasons. One is that the melting temperature of tungsten 0:19:08.720 --> 0:19:12.480 is really high, so you can heat tungsten up quite 0:19:12.520 --> 0:19:16.840 a bit and not worry about it being um melting 0:19:16.840 --> 0:19:20.000 away that that that's obviously another issue with light bulbs. Right, 0:19:20.040 --> 0:19:22.760 you heat up materials, some material is gonna melt, and 0:19:22.800 --> 0:19:25.640 it might melt before you hit that draper point, which 0:19:25.640 --> 0:19:28.080 would be bad because you wouldn't get any light out 0:19:28.119 --> 0:19:31.000 of it. You would just get a you know, a 0:19:31.040 --> 0:19:36.120 glass cylinder of hot molten sludge. Um hot molten sludge 0:19:36.160 --> 0:19:38.720 would be a great name for a band. It is. 0:19:39.200 --> 0:19:42.320 It is, however, very thin. The filament is very thin, 0:19:42.400 --> 0:19:46.280 as anyone who has uh smacked a light bulb hard 0:19:46.400 --> 0:19:49.119 enough to break the filament but not hard enough to 0:19:49.160 --> 0:19:52.960 break the glass knows that's really annoying. That's another really 0:19:52.960 --> 0:19:57.840 annoying thing about changing light bulbs. Oh man did I Yeah, 0:19:58.119 --> 0:20:01.040 just ruined it perfectly good by bulbs. So yeah, it's 0:20:01.119 --> 0:20:04.800 very thin again, that's to increase resistance. That's another thing. 0:20:04.840 --> 0:20:10.280 Is that a a a copper wire, for example, the 0:20:10.280 --> 0:20:13.159 the greater the diameter of a copper wire, the lower 0:20:13.200 --> 0:20:18.360 the resistance. So if you have a very um thin 0:20:18.480 --> 0:20:21.040 copper wire, the resistance is greater. That means it's going 0:20:21.080 --> 0:20:23.600 to also generate more heat as a result. Well, this tungsten, 0:20:23.720 --> 0:20:26.879 same thing. I mean, this same principle applies across all materials. 0:20:27.520 --> 0:20:32.040 Tungsten filament is very very very thin. It's actually coiled twice. 0:20:33.160 --> 0:20:36.160 The first coil is done to decrease it's you know, 0:20:36.440 --> 0:20:39.280 the length, and then after you've coiled it once, you 0:20:39.359 --> 0:20:43.560 coil it a second time around. Uh. These these support 0:20:43.600 --> 0:20:49.560 wires and UH that helps when the tungsten heats up, 0:20:49.640 --> 0:20:53.399 it starts to generate, you know, give off these photons. Uh. 0:20:53.520 --> 0:20:57.399 It helps, uh concentrate that light so that you have 0:20:57.560 --> 0:21:00.200 enough for it to be useful. Because again, you want 0:21:00.200 --> 0:21:02.320 to give enough energy there for you to have visible 0:21:02.400 --> 0:21:05.200 light that you can actually see stuff by, but you 0:21:05.240 --> 0:21:06.840 don't want to have to pour in more energy than 0:21:07.119 --> 0:21:10.240 was necessary. And we should point out incandescent bulbs not 0:21:10.600 --> 0:21:15.560 terribly efficient. No, we think about heat being a a 0:21:15.600 --> 0:21:19.320 wasted form of energy in this case, and how hot 0:21:19.359 --> 0:21:22.919 and incandescent bulb gets. And it's also giving out photons 0:21:22.960 --> 0:21:28.000 outside the range of visible light, so you're getting you know, 0:21:28.119 --> 0:21:31.200 infrared light and maybe even ultraviolet light from from these 0:21:31.280 --> 0:21:34.240 light bulbs. Well that that means that again it's a 0:21:34.320 --> 0:21:36.560 drop in efficiency. I mean, yeah, it's giving off light, 0:21:36.600 --> 0:21:38.439 but we can't see it, so it doesn't do us 0:21:38.480 --> 0:21:42.480 any good, not not in a normal application. Anyway, you know, 0:21:43.080 --> 0:21:46.440 if you're doing something that required infrared or ultraviolet light, 0:21:46.440 --> 0:21:48.520 than sure, although there are better ways of doing that 0:21:48.520 --> 0:21:51.560 than using a regular incandescent light bulb. I mean you 0:21:51.720 --> 0:21:54.960 you could you could even cook brownies with it, which 0:21:55.000 --> 0:21:58.200 is with an easy bake oven. It's funny because I 0:21:58.359 --> 0:22:01.760 don't think people not everyone realizes this. It's not like 0:22:01.800 --> 0:22:06.000 a secret. But um, the the older easy bake ovens, especially, 0:22:06.000 --> 0:22:08.359 they're they're essentially using the heat from a lightbulb to 0:22:08.560 --> 0:22:12.679 cook uh, you know, very simple cakes and brownies and 0:22:12.720 --> 0:22:17.040 things like that. Right now, the you know, you might 0:22:17.080 --> 0:22:20.200 ask what's inside a lightbulb? Besides all this stuff, there's 0:22:20.200 --> 0:22:23.240 actually a gas that's inside most incandescent light bulbs, and 0:22:23.280 --> 0:22:25.679 it's usually are gone, which is an uh it's an 0:22:25.680 --> 0:22:29.800 inert gas, meaning it does not react to other stuff. Hey, 0:22:29.800 --> 0:22:34.880 are gone gas. That's a tornado outside. Yeah, So like, oh, 0:22:34.960 --> 0:22:37.520 you never do anything now that you want it to 0:22:37.560 --> 0:22:41.720 be inert because obviously, like something like oxygen, then the 0:22:41.760 --> 0:22:46.240 tungsten would start to burn. It would dramatically decrease the 0:22:46.320 --> 0:22:50.080 life lifespan of your average light bulb. So they pump 0:22:50.160 --> 0:22:53.400 the oxygen, they pump air out of the glass. Globe 0:22:53.920 --> 0:22:57.320 and fill it with are gone gas. Yep. And so 0:22:57.520 --> 0:22:59.600 you might say, well, why why not just have a 0:22:59.680 --> 0:23:03.960 vacu mist of argon gas. The reason for that is that, uh, 0:23:04.000 --> 0:23:07.120 at that high temperature, you have another problem besides combustion, 0:23:07.200 --> 0:23:09.800 even if you don't have auction, the other problem is evaporation. 0:23:11.119 --> 0:23:15.600 Atoms from the tungsten will actually evaporate off the filament 0:23:15.680 --> 0:23:18.760 because of those high temperatures, and over time that means 0:23:18.760 --> 0:23:21.000 that you're losing you know, every time you're using that 0:23:21.080 --> 0:23:25.000 light bulb, you're losing tungsten. With the old light bulb, Yeah, 0:23:25.640 --> 0:23:27.639 and with the old light bulbs, you would actually have 0:23:27.840 --> 0:23:31.240 the tungsten start to evaporate away and coat the inside 0:23:31.280 --> 0:23:32.920 of the light bulbs, So the light bulb would get 0:23:33.200 --> 0:23:36.360 more and more dim both because there was less filament 0:23:36.440 --> 0:23:39.200 to light and because all the filament that was gone 0:23:39.280 --> 0:23:41.800 is now coating the inside of the light bulb making 0:23:41.840 --> 0:23:46.000 it darker. So by using argon, what it actually acts 0:23:46.040 --> 0:23:48.760 as a sort of a sort of a barrier. These 0:23:48.840 --> 0:23:53.679 atoms from tungsten will come off the filament, bump into 0:23:53.920 --> 0:23:58.520 a an argon atom, and then because argon's a nerd, 0:23:58.560 --> 0:24:02.000 it's not going to act with that. That um energy, 0:24:02.520 --> 0:24:05.600 or that that particle rather the particle then returns to 0:24:07.080 --> 0:24:11.679 the strip of tungsten um. So it acts as kind 0:24:11.680 --> 0:24:15.240 of a cushion. It's just pushing the the atoms back 0:24:15.359 --> 0:24:18.679 to the tungsten. Keeping that filament last to last longer 0:24:19.640 --> 0:24:23.639 very important. And so that's the basic premise behind these 0:24:23.720 --> 0:24:28.320 incandescent bulbs. They you know, they get to a pretty 0:24:29.160 --> 0:24:33.919 hot temperature. We're talking around degrees celsius or four thousand 0:24:33.960 --> 0:24:38.280 degrees fahrenheit um. Because again, you want to put out 0:24:38.400 --> 0:24:40.560 enough visible light for it to be useful. Now that 0:24:40.600 --> 0:24:45.440 all depends on the wattage of the bulb. Yeah, which 0:24:46.040 --> 0:24:49.359 generally speaking, you can think of his brightness, um, it's 0:24:49.400 --> 0:24:52.840 it's kind of or or really you can think of 0:24:52.880 --> 0:24:55.960 his brightness or how hot that tungsten's getting inside the 0:24:56.080 --> 0:25:01.880 light bulb. That's what that kind of translates into. Uh 0:25:01.920 --> 0:25:04.359 and UH interesting. We have an article on the site 0:25:04.359 --> 0:25:07.240 how light Bulbs Work and how stuff Works dot com. 0:25:07.520 --> 0:25:11.200 Great article, great illustrations, a fun read. I mean, I 0:25:11.560 --> 0:25:13.960 really do think that it's actually you would think it's 0:25:14.000 --> 0:25:15.879