WEBVTT - TechStuff Gets a Bright Idea 0:00:02.520 --> 0:00:05.520 Get in touch with technologies with tech Stuff from how 0:00:05.559 --> 0:00:13.880 stuff works dot com. Hello again, everyone in Welcome to 0:00:14.320 --> 0:00:16.640 tech Stuff. My name is Chris Poulette and I am 0:00:16.640 --> 0:00:19.120 an editor at how stuff works dot com. Sitting across 0:00:19.120 --> 0:00:23.200 from me, well as usual, but dancing this time, his 0:00:23.320 --> 0:00:26.720 senior writer, Jonathan Strickland. Hey, there, I just looked up 0:00:26.760 --> 0:00:30.240 and there he was doing that thing, getting my getting 0:00:30.240 --> 0:00:32.920 my energy up. Actually, one of the things that uh, 0:00:33.200 --> 0:00:35.879 you know, we start the episode off pretty traditionally. One 0:00:35.880 --> 0:00:38.720 of the things that we had as an early ritual 0:00:38.840 --> 0:00:41.200 as we recorded Tech Stuff was Jonathan and I would 0:00:41.240 --> 0:00:45.120 be sitting here in the virtual darkness and someone we 0:00:45.159 --> 0:00:47.400 had different engineers over the time, over the years now, 0:00:47.440 --> 0:00:49.600 but someone would come in and turn on the lights 0:00:50.000 --> 0:00:56.680 and good lighted begs. But we wanted to talk a 0:00:56.680 --> 0:01:00.480 little bit about light, specifically light bulbs to day. So 0:01:00.600 --> 0:01:03.760 what a brilliant idea of those were? You know, before lightbulbs, 0:01:04.480 --> 0:01:07.120 Before light bulbs, there was no way to indicate that 0:01:07.160 --> 0:01:12.600 you had an idea. Yeah, yeah, there's no there's no yeah, 0:01:13.120 --> 0:01:16.199 pre light bulb there was no ting before we get 0:01:16.280 --> 0:01:20.039 into how light bulbs work in their history and everything. 0:01:20.040 --> 0:01:22.360 I want to lay down a little physics for you. 0:01:22.560 --> 0:01:27.520 All right, go ahead and enlighten us. I see, So 0:01:27.680 --> 0:01:30.920 we are talking about light and what is light. Well, 0:01:31.000 --> 0:01:35.080 light is made up of these very tiny particle like 0:01:35.560 --> 0:01:41.880 packets called photons. They've got energy, they have momentum, but 0:01:42.160 --> 0:01:46.000 there's one thing they do not have charge accounts mass 0:01:47.880 --> 0:01:51.040 or I was going they have no mass, but not 0:01:51.200 --> 0:01:55.640 no moss. Photons are these packets of energy. They have 0:01:55.760 --> 0:01:59.960 momentum but not mass. And these particles, these these photons 0:02:00.680 --> 0:02:06.200 are emitted by atoms. Once you have excited an atom 0:02:06.280 --> 0:02:09.600 to the point where it's electron starts to move out 0:02:09.639 --> 0:02:14.560 of its normal orbit and goes into a further orbit 0:02:14.639 --> 0:02:18.360 from the atoms nucleus. And once once you remove the 0:02:18.480 --> 0:02:22.360 energy source from that atom, the electron will eventually return 0:02:22.480 --> 0:02:25.840 to its normal orbit around the nucleus. But it has 0:02:25.880 --> 0:02:29.800 to it has to get rid of that energy that 0:02:29.960 --> 0:02:33.440 you have pushed into it. Right, Energy is not created 0:02:33.520 --> 0:02:37.639 or destroyed, it's just transferred. So this electron, as it's 0:02:37.680 --> 0:02:39.919 coming back down to its normal orbital is going to 0:02:40.080 --> 0:02:43.560 shed off energy, and in this case the energy is 0:02:43.560 --> 0:02:48.240 in the form of photons. Now, photons are going to 0:02:48.320 --> 0:02:52.600 be emitted in the entire spectrum of light. Now humans 0:02:53.080 --> 0:02:56.800 we are capable of perceiving a narrow band of that 0:02:56.919 --> 0:03:03.040 spectrum called the visible spectrum because it's visible to us. Oh, 0:03:03.240 --> 0:03:05.120 I always wondered about that. This is where the whole 0:03:05.200 --> 0:03:08.639 ROYGBIV thing comes in, right. The different wavelengths of light 0:03:08.760 --> 0:03:12.760 dictate what the color is as we perceive it. Uh. 0:03:12.840 --> 0:03:16.320 The but the the light goes well beyond outside the 0:03:16.320 --> 0:03:19.360 the visible range. There's things like ultra violet and infrared, 0:03:19.440 --> 0:03:22.880 and then you get into electromagnetic radiation as you go 0:03:22.960 --> 0:03:27.280 further out. But and anyway, Uh, these photons can come 0:03:27.320 --> 0:03:32.960 into various forms, so you can have a infrared photon 0:03:33.240 --> 0:03:36.600 or ultra violet photons. So uh, if it's in the 0:03:36.640 --> 0:03:39.160 visible light spectrum, we're able to see it. Now that's 0:03:39.200 --> 0:03:44.720 important because that's the whole basis of creating a light bulb. 0:03:44.760 --> 0:03:47.480 As you want to create some sort of device that 0:03:48.040 --> 0:03:52.720 you can used to create photons so that you can 0:03:52.760 --> 0:03:56.720 illuminate an area. And before light bulbs, you didn't really 0:03:56.760 --> 0:03:59.560 have that option unless you set something on fire. Uh. 0:03:59.600 --> 0:04:01.560 And there's a limited number of things we can set 0:04:01.560 --> 0:04:04.480 on fire before we set ourselves on fire, or we 0:04:04.560 --> 0:04:07.440 run out of stuff that is flammable, So it was 0:04:07.480 --> 0:04:09.720 a good idea to try and develop something that could 0:04:10.160 --> 0:04:15.600 create light in another way. Now, uh, how do we 0:04:15.680 --> 0:04:19.520 know about how what is the principle upon which light 0:04:19.520 --> 0:04:24.760 bulbs work. Well, again, if you excite an atom and 0:04:24.920 --> 0:04:27.880 you push those electrons out, when the electrons come back in, 0:04:27.960 --> 0:04:33.160 they emit photons. If you give enough energy to an object, 0:04:33.760 --> 0:04:37.240 then you can emit enough uh photons for it to 0:04:37.279 --> 0:04:39.960 be within the depending upon the nature of that material, 0:04:40.080 --> 0:04:43.039 for it to be within the visible spectrum for it 0:04:43.080 --> 0:04:47.000 to be perceptible. Because even if it's in the visible spectrum, 0:04:47.040 --> 0:04:50.359 if the energy is not great enough, you won't be 0:04:50.400 --> 0:04:53.839 able to see it. And we're all emitting energy all 0:04:53.880 --> 0:04:57.320 the time, like humans are emitting infrared energy all the time, 0:04:57.360 --> 0:04:59.120 and if you had an infrared camera, you'd be able 0:04:59.160 --> 0:05:02.160 to see it even in perfectly dark room. You look 0:05:02.240 --> 0:05:04.400 at the infrared camera, look at a person, you would 0:05:04.440 --> 0:05:07.839 see light as interpreted by the sensor in that camera 0:05:08.040 --> 0:05:10.520 and converted to visible light for us to see. You 0:05:10.520 --> 0:05:12.920 would be able to see that person because they're emitting 0:05:12.920 --> 0:05:17.359 that infrared light. Well, we may even depending on what what, 0:05:17.520 --> 0:05:21.160 depending on the material, it may even be emitting visible light. 0:05:21.200 --> 0:05:23.760 But it might be emitting at levels so low as 0:05:23.800 --> 0:05:27.440 to be imperceptible to humans. So if you add more energy, 0:05:27.680 --> 0:05:31.920 you can boost that and actually see the visible light. Uh. 0:05:32.040 --> 0:05:35.560 And this can happen with things like solid materials. And 0:05:35.600 --> 0:05:39.839 there was a fellow named John William Draper who in 0:05:39.960 --> 0:05:44.920 eighty seven demonstrated that solid materials, almost all of them, 0:05:45.040 --> 0:05:50.440 will glow once they reach a temperature of seven kelvin. 0:05:51.960 --> 0:05:56.000 Kelvin's a scientific scale for temperatures. Kelvin is what we 0:05:56.120 --> 0:05:59.800 have when you get to zero kelvin. That says that 0:06:00.080 --> 0:06:02.520 as cold as you can get, it actually refers to 0:06:02.560 --> 0:06:06.400 molecular movement, and at zero kelvin, there is no molecular movement. 0:06:07.160 --> 0:06:11.559 So that's like the deepest depths of space where there's 0:06:11.760 --> 0:06:16.520 nothing absolutely absolutely uh So, if you wanted to convert 0:06:16.600 --> 0:06:19.520 that into degrees that we're more familiar with most of 0:06:19.600 --> 0:06:22.440 us anyway, it would be about five and twenty five 0:06:22.480 --> 0:06:26.800 degrees celsius or nine seventy seven degrees fahrenheit, And at 0:06:26.800 --> 0:06:30.479 that temperature solid materials will start to glow. We call 0:06:30.520 --> 0:06:34.320 it the Draper point. Now, in order to have a 0:06:35.000 --> 0:06:38.840 object glow at a uh at a at an intensity 0:06:38.920 --> 0:06:41.719 bright enough for it to illuminate, say a room, you 0:06:41.760 --> 0:06:45.279 will have to put in more energy than that, right, 0:06:45.400 --> 0:06:47.560 because this is talking about they start to glow, but 0:06:47.600 --> 0:06:49.440 that doesn't mean that they're glowing so brightly as to 0:06:49.480 --> 0:06:52.960 illuminate an entire room. That's where it starts. So but 0:06:53.040 --> 0:06:54.880 you know, you've you've probably seen this. If you've ever 0:06:54.880 --> 0:06:58.400 seen a blacksmith work, then you know the blacksmith might 0:06:58.400 --> 0:07:00.240 be heating up iron and when they take that out 0:07:00.320 --> 0:07:05.279 it's glowing red. Or a glass blower or lava. You know, 0:07:05.320 --> 0:07:09.200 there's lots of stuff that tends to lava. It's not 0:07:09.279 --> 0:07:12.280 all manmade, but there's lots of stuff out there that 0:07:12.440 --> 0:07:17.600 um that that demonstrates this. So that's the principle. But 0:07:17.600 --> 0:07:23.160 but the idea behind an electric light source actually predates 0:07:23.280 --> 0:07:28.920 Draper's discovery. Really yes, back in well the early eighteen hundreds. 0:07:28.920 --> 0:07:31.800 I've seen I've seen reports from eighteen o six all 0:07:31.840 --> 0:07:35.080 the way up to eighteen o nine. There's some discrepancies there. 0:07:35.560 --> 0:07:40.800 But an English chemist and inventor named Sir Humphrey Davy, 0:07:41.400 --> 0:07:44.280 named Humphrey Davy, he was designated a night So that's 0:07:44.320 --> 0:07:50.080 the sir. He connected a battery to a strip of charcoal, 0:07:51.000 --> 0:07:53.680 and he used the electricity to actually heat up the 0:07:53.760 --> 0:07:56.640 charcoal to the point where it started to glow, which 0:07:56.680 --> 0:08:02.360 created technically the first electric arc lamp. Uh. This was 0:08:02.440 --> 0:08:09.040 not a viable means of illumination as it was hard 0:08:09.080 --> 0:08:11.120 to do. It required a lot of energy. The battery 0:08:11.200 --> 0:08:13.640 drained really quickly, the carbon burned at such a or 0:08:14.680 --> 0:08:21.160 it got so hot as to be incredibly dangerous for uh, say, 0:08:21.200 --> 0:08:24.200 I don't know a typical house um. So it was 0:08:24.240 --> 0:08:27.520 not something that was going to immediately be adopted into 0:08:27.560 --> 0:08:33.640 every household, but it was proving a concept. Uh. Also, 0:08:33.840 --> 0:08:36.000 by the way, Sir Humphrey Davy did go on to 0:08:36.120 --> 0:08:39.280 invent many things, including the Davy lamp, which was not 0:08:39.760 --> 0:08:42.679 an electrical lamp. It was a gas lamp. There was 0:08:42.720 --> 0:08:45.360 a gas lamp that had a mesh screen that would 0:08:45.400 --> 0:08:51.040 surround the flame so that miners meaning people who mind 0:08:51.120 --> 0:08:55.120 the earth, not people who are underage miners, could take 0:08:55.200 --> 0:08:58.640 the lamps, although depending in England at that point in time, 0:08:58.880 --> 0:09:02.240 the two may have been the same. Aim. Hey, our 0:09:02.320 --> 0:09:04.880 history has not always been a nice one. But the 0:09:04.920 --> 0:09:09.240 miners could take a lamp down below the ground, and 0:09:09.280 --> 0:09:11.720 even if they encountered a pocket of gas. The mesh 0:09:11.760 --> 0:09:15.440 would actually, this fine mesh would prevent the gas and 0:09:15.480 --> 0:09:19.080 the flame from making friends and becoming a big boom. 0:09:19.840 --> 0:09:24.720 Very important for miners of both types. So the he 0:09:24.800 --> 0:09:27.160 did invent that, Again not electrical, but I thought it 0:09:27.200 --> 0:09:30.920 was an interesting aside. Moving ahead back in the eighty one, 0:09:32.520 --> 0:09:38.360 Frederick de Moulins, and I'm sure I have completely mispronounced 0:09:38.360 --> 0:09:41.559 his name, and I apologized profusely for that. Another Englishman, 0:09:42.800 --> 0:09:45.400 Yeah it could be. He patented a light bulb in 0:09:45.520 --> 0:09:47.880 eight forty one, and this one was comprised of a 0:09:47.920 --> 0:09:51.200 glass case and a burner or burners actually made of 0:09:51.280 --> 0:09:58.400 carbon and in expensive material you may know as platinum. Yeah, 0:09:58.440 --> 0:10:01.800 you thought that led light bulbs were expensive, so uh 0:10:02.200 --> 0:10:06.720 he he patented that design. Again not really practical for 0:10:07.400 --> 0:10:12.960 for every day or even industrial use. An American inventor 0:10:13.080 --> 0:10:15.560 named J. W. Starr received a patent for a light 0:10:15.559 --> 0:10:19.559 bulb that used a carbon burner. Um and then the 0:10:19.600 --> 0:10:23.120 next few decades were spent among inventors trying to find 0:10:23.120 --> 0:10:27.160 a way to perfect the discoveries these earlier inventors had found, 0:10:27.960 --> 0:10:32.440 so that you could create a light bulb that made sense, 0:10:33.320 --> 0:10:37.000 that that was efficient, that could light well, that was 0:10:37.040 --> 0:10:40.400 not going to be prohibitively expensive. And there are two 0:10:40.520 --> 0:10:44.360 names in particular that pop up all the time, one 0:10:44.400 --> 0:10:48.160 of them being probably the most famous uh connected to 0:10:48.200 --> 0:10:51.720 the light bulb, which is Thomas Edison. Yes, it's funny, 0:10:51.880 --> 0:10:54.560 as we were recording this, we are rapidly approaching the 0:10:54.760 --> 0:10:59.400 hundred thirty third anniversary of the first test of Edison's 0:10:59.440 --> 0:11:02.800 incandescent light bulb. Yeah. Now, it is important to note 0:11:03.000 --> 0:11:05.520 Edison was not the person who invented the light bulb. 0:11:05.600 --> 0:11:07.960 He was not even the person to invent the incandescent 0:11:08.120 --> 0:11:11.760 light bulb, but he was someone who perfected that design 0:11:11.800 --> 0:11:16.600 and made it viable as an actual product. Yeah. Now, 0:11:16.679 --> 0:11:22.200 it's it's important to note, um that these these early lightbulbs, uh, 0:11:22.280 --> 0:11:25.400 you know, not only were homes not really wired. Actually, 0:11:25.480 --> 0:11:27.720 the light bulb, I would argue, based on my research 0:11:28.120 --> 0:11:31.760 the over the past, you know, the past times that 0:11:31.760 --> 0:11:34.000 we've done tech stuff, we've talked about Edison and Tesla 0:11:34.040 --> 0:11:36.920 and the lightbulb actually was sort of the key to 0:11:37.000 --> 0:11:41.120 getting homes wired for electricity. Yeah, I mean you and 0:11:41.200 --> 0:11:44.360 it made sense because suddenly you had households that could 0:11:44.440 --> 0:11:50.400 be uh safely with air quotes around that lit after 0:11:50.480 --> 0:11:56.160 dark and extend the useful uh time human being could 0:11:56.240 --> 0:12:01.000 get stuff done, because otherwise, when night fell, we might 0:12:01.040 --> 0:12:03.240 as well just go to bed because it was gonna 0:12:03.280 --> 0:12:05.800 be pretty dark. Well, you know, we're early to bed 0:12:05.800 --> 0:12:08.360 and early to rise, as they say, early to bed, 0:12:08.360 --> 0:12:11.040 early to rise, because otherwise you're barking your ship on 0:12:11.080 --> 0:12:14.559 the coffee table. Well, yeah, that's that's true. Well, gas lamps, 0:12:14.679 --> 0:12:18.839 uh were very very popular. But they were I mean, 0:12:18.880 --> 0:12:24.079 in addition to being obviously inherently somewhat dangerous um and 0:12:24.160 --> 0:12:29.840 oil lamps, but they were um smoky, um. They were dirty, 0:12:30.320 --> 0:12:33.559 so you know, I'm sure they probably didn't smell all 0:12:33.600 --> 0:12:36.440 that great um. But the problem with these early light 0:12:36.480 --> 0:12:40.120 bulbs is that they weren't very practical. O. Hey, look 0:12:40.120 --> 0:12:43.320 I got yeah, well, so much for that one. Another one. 0:12:43.360 --> 0:12:47.480 There was another inventor, an Englishman. The Englishman named Sir 0:12:47.600 --> 0:12:50.640 Joseph Swan, who was working on light bulbs around the 0:12:50.679 --> 0:12:54.880 same time as Edison. And Swan's bulb used carbonized paper 0:12:55.040 --> 0:12:58.040 as the burner, which worked pretty well except that it 0:12:58.080 --> 0:13:01.280 didn't last terribly long. And in fact, this was a 0:13:01.280 --> 0:13:05.679 problem that a lot of lightbulb. Researchers were encountering that, 0:13:06.559 --> 0:13:09.520 including Edison. The first problem was, all right, well, we've 0:13:09.559 --> 0:13:13.160 we found uh that if you if you run enough 0:13:13.200 --> 0:13:16.760 electricity through some sort of object, you can heat it 0:13:16.800 --> 0:13:20.720 up enough so that it begins to glow. But if 0:13:20.800 --> 0:13:26.600 that item is exposed to oxygen, then it will burn. 0:13:27.320 --> 0:13:29.320 So even if you found a material that does not 0:13:29.600 --> 0:13:32.240 melt at a high temperature, it would burn, it would 0:13:32.280 --> 0:13:35.040 combust at a high enough temperature because it'd be you know, 0:13:35.320 --> 0:13:37.839 it would be adjacent to oxygen, which you know that 0:13:38.000 --> 0:13:41.040 that's part of the fuel you need, you know, in 0:13:41.120 --> 0:13:45.360 order to have a fire. UM. So the you had 0:13:45.360 --> 0:13:47.280 to close it off from oxygen, which is why they 0:13:47.280 --> 0:13:49.920 were these these vacuum tubes essentially is what they create, 0:13:50.000 --> 0:13:56.840 these vacuum containers. UM. But once they got through that, 0:13:56.880 --> 0:13:59.760 they had to find what's the right material to use. Actually, 0:13:59.800 --> 0:14:05.040 what Edison ended up using at first was bamboo. He 0:14:05.120 --> 0:14:10.880 took Japanese bamboo and carbonized it and created a filament. 0:14:11.320 --> 0:14:14.840 In this case, what a filament is is this really long, long, long, 0:14:14.880 --> 0:14:18.960 long strip of material that is then coiled so that 0:14:19.080 --> 0:14:23.720 you can decrease the space that it needs to um 0:14:23.920 --> 0:14:26.280 to fit into whatever you want to put it in, 0:14:26.560 --> 0:14:29.360 so it's got a lot of surface areas. Then the 0:14:29.440 --> 0:14:35.080 resistance is high. A resistance in electricity is the the 0:14:35.120 --> 0:14:38.400 materials resistance to electrons flowing through it freely. The more 0:14:38.440 --> 0:14:41.400 resistance there is in general, Okay, you've got greater resistance, 0:14:41.440 --> 0:14:44.520 you have greater heat. Well, the secret to the light 0:14:44.600 --> 0:14:46.680 here is the amount of heat that's being generated. That's 0:14:46.680 --> 0:14:50.800 the energy that is creating this whole system of electrons 0:14:50.880 --> 0:14:53.080 being pushed out and then when they start coming back in, 0:14:53.120 --> 0:14:57.520 the photons are being let out. So let let the 0:14:57.520 --> 0:15:01.120 photons out? Who let the photons out? That was as 0:15:01.160 --> 0:15:03.960 an a swan as it turns out. Um, it's interesting 0:15:03.960 --> 0:15:07.480 because then Edison Edison ended up hiring what his first 0:15:07.560 --> 0:15:11.560 his first light bulb design used a temperature controlled switch 0:15:12.280 --> 0:15:17.080 to try and keep the material at the right temperature 0:15:17.120 --> 0:15:21.080 so that it would the light bulb would remain lit longer. 0:15:21.120 --> 0:15:23.280 Because that was an early problem with these light bulbs 0:15:23.360 --> 0:15:26.280 is that their their utility was low because they couldn't 0:15:26.280 --> 0:15:29.240 you couldn't burn them for very long. But this was 0:15:29.280 --> 0:15:33.480 a problem because the the temperature control controlled switch, once 0:15:33.480 --> 0:15:36.160 a certain temperature was hit, it would switch off right, 0:15:36.280 --> 0:15:38.800 the light would go off, and so it started creating 0:15:38.800 --> 0:15:43.120 this flickering problem and made the bulb practically unusable. So 0:15:43.160 --> 0:15:47.480 he then hired a physicist from Princeton named Francis Upton, 0:15:47.920 --> 0:15:52.920 who led Edison's research team working on light bulbs, to 0:15:53.200 --> 0:15:55.800 start practicing with other stuff. That's when they came upon 0:15:55.880 --> 0:15:59.440 the idea of using the bamboo as a filament. Um. 0:15:59.680 --> 0:16:02.880 Swan and Edison ended up battling each other. Edison ended 0:16:02.960 --> 0:16:07.120 up taking patent lawsuits against Swan, but then ultimately the 0:16:07.120 --> 0:16:10.960 two of them formed a partnership together and they created 0:16:10.960 --> 0:16:17.160 the Edison Swan United Company. Teamwork, teamwork. Um. Yeah, just so, 0:16:17.480 --> 0:16:19.840 just so you guys know, patent wars are not a 0:16:19.880 --> 0:16:24.240 new thing. Oh no, not in the least. Um. Yeah, 0:16:24.440 --> 0:16:27.520 it's funny. While u while carbonized bamboo sounds like an 0:16:27.640 --> 0:16:32.600 ingredient for a hipster sandwich, Um, it did have the 0:16:32.640 --> 0:16:38.400 ability to burn for more than which you know, back 0:16:38.400 --> 0:16:40.720 in that time, that was pretty nice for a for 0:16:40.720 --> 0:16:45.040 a light bulb. Yeah, and uh, this served as the 0:16:45.080 --> 0:16:47.760 basis for what future light bulbs would be. And then 0:16:48.400 --> 0:16:51.440 we ended up shifting to a different type of filament. 0:16:51.480 --> 0:16:52.960 But we'll get into that in a second. So let's 0:16:53.000 --> 0:16:58.240 talk about the basic anatomy of an incandescent light bulb. 0:16:58.280 --> 0:17:00.600 And don't worry Floresce in an L. E. D. Fans, 0:17:00.920 --> 0:17:03.600 We're gonna get to you too. You just sit tight. 0:17:04.359 --> 0:17:09.520 So the incandescent bulb, You've got two contacts to two 0:17:09.600 --> 0:17:13.880 electrical context on this on a typical incandescent bulb. One 0:17:13.920 --> 0:17:16.000 of them is at the very end of the bulb, 0:17:16.359 --> 0:17:19.960 that's the base of the bulb, and the other is 0:17:20.000 --> 0:17:25.000 in the actual treads that you screw into your um 0:17:25.400 --> 0:17:29.560 light bulb socket. Yeah. Actually usually has a squeaky noise 0:17:29.600 --> 0:17:33.320 which has that perfect pitch to give me the heavy gbs. 0:17:33.840 --> 0:17:35.960 It's like the fingernails on the chalkboard type thing. It's 0:17:35.960 --> 0:17:39.160 like almost every single light bulb in my house makes 0:17:39.160 --> 0:17:44.639 that noise. And so it's a physically demanding task for 0:17:44.720 --> 0:17:47.840 me because well, I guess psychologically really more than physically, 0:17:47.840 --> 0:17:52.200 because because I I suffer trauma. One follows the other. 0:17:53.440 --> 0:17:55.119 How many how many Jonathans does it take to you 0:17:55.440 --> 0:17:58.200 screw in a light bulb? Yeah, well, after the first one, 0:17:58.240 --> 0:18:01.800 it takes a few others to common down. Yeah, I'm 0:18:01.840 --> 0:18:03.920 not afraid of the dark. I'm just afraid of changing 0:18:04.000 --> 0:18:06.879 light bulbs, so that's not really true. I just don't 0:18:06.920 --> 0:18:09.520 like doing it. But anyway, these mental contacts are what 0:18:09.840 --> 0:18:14.720 create the the circuit, right, so that the circuits complete. 0:18:14.760 --> 0:18:19.119 When these two contacts are are in contact with the 0:18:19.160 --> 0:18:24.000 rest of the electrical system. On um, the contacts are 0:18:24.000 --> 0:18:28.159 attached to some wires and those wires are attached to 0:18:28.280 --> 0:18:31.960 the filament. Now, in this case, the filament is no 0:18:32.040 --> 0:18:36.160 longer bamboo. For your typical incandescent bulb, it's usually tungsten. 0:18:36.800 --> 0:18:40.040 And the reason why it's tungsten is a couple of 0:18:40.080 --> 0:18:43.160 different reasons. One is that the melting temperature of tungsten 0:18:43.359 --> 0:18:47.160 is really high, so you can heat tungsten up quite 0:18:47.160 --> 0:18:51.480 a bit and not worry about it being um melting 0:18:51.480 --> 0:18:54.640 away that. That's obviously another issue with light bulbs. Right 0:18:54.680 --> 0:18:57.399 you heat up materials, some material is gonna melt, and 0:18:57.440 --> 0:19:00.280 it might melt before you hit that draper point, which 0:19:00.320 --> 0:19:02.720 would be bad because you wouldn't get any light out 0:19:02.720 --> 0:19:05.600 of it. You would just get a you know, a 0:19:05.680 --> 0:19:10.760 glass cylinder of hot molten sludge. Um Hot molten sludge 0:19:10.760 --> 0:19:13.640 would be a great name for a band. It is, uh. 0:19:13.840 --> 0:19:16.960 It is, however, very thin the filament is very thin. 0:19:17.040 --> 0:19:20.920 As anyone who has uh smacked a light bulb hard 0:19:21.040 --> 0:19:23.760 enough to break the filament but not hard enough to 0:19:23.800 --> 0:19:27.560 break the glass knows that's really annoyed. That's another really 0:19:27.600 --> 0:19:32.480 annoying thing about changing lightbulbs. Oh when did I yeah, 0:19:32.720 --> 0:19:35.680 just ruined a perfectly good bye bulbs. So, yeah, it's 0:19:35.760 --> 0:19:39.440 very thin. Again, that's to increase resistance. That's another thing, 0:19:39.480 --> 0:19:44.920 is that a a a copper wire, for example, the 0:19:44.920 --> 0:19:47.800 the greater the diameter of a copper wire, the lower 0:19:47.840 --> 0:19:53.000 the resistance. So if you have a very um thin 0:19:53.119 --> 0:19:55.679 copper wire, the resistance is greater. That means it's going 0:19:55.680 --> 0:19:57.639 to also generate more heat as a result. Well, this 0:19:57.760 --> 0:20:00.760 tungusten same thing. I mean, this same principle applies across 0:20:00.800 --> 0:20:04.960 all materials. U tungsten filament is very very very thin. 0:20:05.440 --> 0:20:09.240 It's actually coiled twice. The first coil is done to 0:20:09.520 --> 0:20:13.240 decrease it's you know, the length, and then after you've 0:20:13.240 --> 0:20:16.639 coiled it once, you coil it a second time around. Uh. 0:20:16.680 --> 0:20:22.159 These these support wires, and uh that helps when the 0:20:23.280 --> 0:20:26.600 tungsten heats up, it starts to generate, you know, give 0:20:26.640 --> 0:20:30.760 off these photons. Uh, it helps, Uh, concentrate that light 0:20:31.000 --> 0:20:33.240 so that you have enough for it to be useful, 0:20:33.280 --> 0:20:36.040 because again, you want to give enough energy there for 0:20:36.119 --> 0:20:38.360 you to have visible light that you can actually see 0:20:38.400 --> 0:20:40.600 stuff by, but you don't want to have to pour 0:20:40.640 --> 0:20:43.120 in more energy than was necessary. And we should point 0:20:43.160 --> 0:20:47.639 out incandescent bulbs not terribly efficient. No, we think about 0:20:47.840 --> 0:20:52.680 heat being a a wasted form of energy in this case, 0:20:53.160 --> 0:20:56.160 and how hot and incandescent bulb gets. And it's also 0:20:56.200 --> 0:21:01.520 giving out photons outside the range of visible light, so 0:21:01.640 --> 0:21:04.800 you're getting you know, infrared light and maybe even ultraviolet 0:21:04.840 --> 0:21:07.680 light from from these light bulbs. Well that that means 0:21:07.680 --> 0:21:10.400 that again it's a drop in efficiency. I mean, yeah, 0:21:10.440 --> 0:21:12.399 it's giving off light, but we can't see it, so 0:21:12.440 --> 0:21:15.000 it doesn't do us any good, not not in a 0:21:15.080 --> 0:21:19.040 normal application. Anyway. You know, if you're doing something that 0:21:19.280 --> 0:21:22.159 required infrared or ultraviolet light, than sure, although there are 0:21:22.160 --> 0:21:25.880 better ways of doing that than using a regular incandescent lightbulb. Yeah, 0:21:25.920 --> 0:21:28.560 I mean you you could. You could even cook brownies 0:21:28.600 --> 0:21:32.240 with it, which is with an easy bake oven. It's 0:21:32.240 --> 0:21:35.720 funny because I don't think people, not everyone realizes this. 0:21:35.960 --> 0:21:39.439 It's not like a secret. But um, the the older 0:21:39.480 --> 0:21:42.040 easy bake ovens, especially they're they're essentially using the heat 0:21:42.080 --> 0:21:45.280 from a lightbulb to cook uh, you know, very simple 0:21:46.240 --> 0:21:50.080 cakes and brownies and things like that. Right now, the 0:21:51.080 --> 0:21:53.840 you know, you might ask what's inside a lightbulb? Besides 0:21:53.960 --> 0:21:56.720 all this stuff, there's actually a gas that's inside most 0:21:56.760 --> 0:21:59.280 incandescent light bulbs, and it's usually are gone, which is 0:21:59.280 --> 0:22:01.679 an uh it's an inert gas, meaning it does not 0:22:01.800 --> 0:22:06.199 react to other stuff. Hey, are gone gas. It's a 0:22:06.200 --> 0:22:10.960 tornado outside. So like, oh, you never do anything now 0:22:11.040 --> 0:22:14.360 that you want it to be inert because obviously, like 0:22:14.560 --> 0:22:17.640 something like oxygen, then the tungsten would start to burn. 0:22:18.320 --> 0:22:23.199 It would dramatically decrease the life lifespan of your average 0:22:23.280 --> 0:22:26.360 light bulb. So they pump the oxygen, They pump air 0:22:26.440 --> 0:22:29.600 out of the glass globe and fill it with our 0:22:29.680 --> 0:22:33.000 gone gas. Yep. And so you might say, well, why 0:22:33.080 --> 0:22:35.760 why not just have a vacuum inst of our gone gas. 0:22:36.080 --> 0:22:39.840 The reason for that is that, uh, at that high temperature, 0:22:39.960 --> 0:22:42.400 you have another problem besides combustion, even if you don't 0:22:42.400 --> 0:22:46.679 have oxygen, the other problem is evaporation. Atoms from the 0:22:46.720 --> 0:22:51.000 tungsten will actually evaporate off the filament. Because of those 0:22:51.040 --> 0:22:54.240 high temperatures, and over time, that means that you're losing 0:22:54.359 --> 0:22:56.240 you know, every time you're using that light bulb, you're 0:22:56.280 --> 0:23:00.480 losing tungsten with the old light bulber. Yeah, and with 0:23:00.520 --> 0:23:03.000 the old light bulbs, you would actually have the tungsten 0:23:03.119 --> 0:23:06.040 start to evaporate away and coat the inside of the 0:23:06.080 --> 0:23:08.119 light bulbs, So the light bulb would get more and 0:23:08.160 --> 0:23:11.480 more dim both because there was less filament to light 0:23:11.880 --> 0:23:14.200 and because all the filament that was gone is now 0:23:14.240 --> 0:23:17.200 coating the inside of the light bulb making it darker. 0:23:17.600 --> 0:23:20.840 So uh, by using argon, what it actually acts as 0:23:20.880 --> 0:23:23.920 is sort of a sort of a barrier. These atoms 0:23:23.960 --> 0:23:29.679 from tungsten will come off the filament, bump into a 0:23:29.680 --> 0:23:33.360 an argon atom, and then because argon's a nerd, it's 0:23:33.359 --> 0:23:37.040 not going to act with that that um uh energy 0:23:37.160 --> 0:23:40.240 or that that particle. Rather, the particle then returns to 0:23:41.720 --> 0:23:46.280 the strip of tungsten um. So it acts as kind 0:23:46.320 --> 0:23:49.880 of a cushion. It's just pushing the the atoms back 0:23:50.000 --> 0:23:53.280 to the tungsten. Keeping that filament last to last longer 0:23:54.280 --> 0:23:58.280 very important. And so that's the basic premise behind these 0:23:58.359 --> 0:24:02.280 incandescent bulbs. The a uh, you know, they get to 0:24:02.320 --> 0:24:07.919 a pretty hot temperature. We're talking around degrees celsius or 0:24:07.960 --> 0:24:12.560 four thousand degrees fahrenheit um, because again you want to 0:24:12.560 --> 0:24:14.719 put out enough visible light for it to be useful. 0:24:14.920 --> 0:24:19.680 Now that all depends on the wattage of the bulb. Yeah, 0:24:19.800 --> 0:24:23.639 which generally speaking, you can think of his brightness. Um, 0:24:23.680 --> 0:24:27.360 it's it's kind of or or really you can think 0:24:27.359 --> 0:24:30.560 of his brightness or how hot that tungsten's getting inside 0:24:30.560 --> 0:24:35.880 the light bulb. That's what that kind of translates into. 0:24:36.359 --> 0:24:38.720 Uh and uh. Interesting. We have an article on the 0:24:38.760 --> 0:24:41.879 site how light Bulbs Work and how stuff Works dot com. 0:24:42.119 --> 0:24:45.840 Great article, great illustrations, a fun read. I mean, I 0:24:46.200 --> 0:24:48.600 really do mean that. It's actually you would think it's 0:24:48.600 --> 0:24:50.520 an article about light bulbs, but it really is a 0:24:50.520 --> 0:24:54.560 fun read. And one of my favorite uh facts in 0:24:54.600 --> 0:24:58.399 this is that a typical sixty what bulb has a 0:24:58.440 --> 0:25:02.560 tungsten filament that six and a half feet or two 0:25:02.600 --> 0:25:06.480 meters long and one hundred of an inch thick. I 0:25:06.480 --> 0:25:10.439