WEBVTT - How do microwaves work? 0:00:09.119 --> 0:00:11.479 Or Hey, I know you like to joke that any 0:00:11.560 --> 0:00:14.320 physics question I ask you could be answered with the 0:00:14.440 --> 0:00:17.200 Big Bang. I think it's a pretty solid answer for 0:00:17.239 --> 0:00:20.880 any science question, you know, like why does why does 0:00:20.920 --> 0:00:23.279 this happen? And it's all because of the Big Bang? Man, 0:00:23.320 --> 0:00:26.159 you are like a deep philosopher of science. Sometimes I 0:00:26.200 --> 0:00:28.280 think I just just heard you say the Big Bang 0:00:28.320 --> 0:00:30.760 too many times. Well, I don't mean to burst your bubble, 0:00:30.840 --> 0:00:33.400 but I think I finally found a question where the 0:00:33.400 --> 0:00:36.279 Big Bang is not the valid answer. What could not 0:00:36.360 --> 0:00:55.440 be due to the Big Bang? Keep listening. Hi, am 0:00:55.560 --> 0:00:59.240 orhammy cartoonists and the creator of PhD comics. Hi. I'm 0:00:59.320 --> 0:01:01.800 Daniel Whitson. I'm a particle physicist, and I owe my 0:01:01.840 --> 0:01:04.520 existence to the Big Bang, as do we all, as 0:01:04.560 --> 0:01:07.840 does this podcast. That's right, even this podcast so Welcome 0:01:07.880 --> 0:01:11.240 to Daniel and Jorge Explain the Universe, a production of 0:01:11.319 --> 0:01:14.080 My Heart Radio. Welcome to our podcast, in which we 0:01:14.160 --> 0:01:18.080 explore things big and small, things out there, big and small, 0:01:18.200 --> 0:01:21.200 out there in the universe, and even right here in 0:01:21.240 --> 0:01:24.640 our homes, in our everyday lives. Something that we use 0:01:25.120 --> 0:01:28.000 almost too much. I think perhaps that's right. One of 0:01:28.000 --> 0:01:30.560 the joys of being a physicist is looking around you 0:01:30.800 --> 0:01:33.440 all the time and wondering how does that thing work? 0:01:33.840 --> 0:01:36.480 And that extends to the cosmos and the stars and 0:01:36.520 --> 0:01:38.920 the big question to the universe, but it also applies 0:01:38.959 --> 0:01:41.640 to just stuff happening around you. You know, why does 0:01:41.640 --> 0:01:44.360 that leaf dance that way? Why does the ball bounce 0:01:44.440 --> 0:01:46.319 this way? How do I make this thing happen? Or 0:01:46.440 --> 0:01:48.760 how does this thing in my kitchen do it's thing? 0:01:49.000 --> 0:01:52.360 How does this magic happen? There's crazy physics all around us, right, 0:01:52.400 --> 0:01:56.480 and potentially dangerous sources of radiation in our own homes. 0:01:57.920 --> 0:02:00.600 That's right. Basically the whole universe is crazy physics. I mean, 0:02:00.600 --> 0:02:02.840 that's a good way to summarize the whole thing, right. 0:02:03.040 --> 0:02:05.360 That's a that's an alternate answer to the Big Bang? 0:02:06.840 --> 0:02:09.000 Why why does why does this particle do that? It's 0:02:09.080 --> 0:02:13.200 just crazy physics. It's better than the answer being crazy physicists. Right, 0:02:13.560 --> 0:02:17.880 physicists crazy because of crazy physics. I'm not sure about 0:02:17.880 --> 0:02:20.200 the cause and effect there, Yeah, um, it might be 0:02:20.240 --> 0:02:22.480 the becoming a physicist makes you a little bit crazy 0:02:22.520 --> 0:02:25.639 because you see the world through different eyes. Right, everything 0:02:25.720 --> 0:02:27.480 you look at you try to understand in terms of 0:02:27.520 --> 0:02:30.320 an equation or model, or try to dig down and 0:02:30.400 --> 0:02:33.520 understand how this emergent phenomenon can be explained by tiny 0:02:33.600 --> 0:02:36.160 little particles bumping up against each other. Yeah. So on 0:02:36.200 --> 0:02:39.240 this podcast we usually tackle very big topics like the 0:02:39.280 --> 0:02:42.040 size of the universe or where did the Big band 0:02:42.120 --> 0:02:45.920 come from? But sometimes we like to tackle smaller topics 0:02:46.040 --> 0:02:49.120 or topics that are in everyone's everyday life. Yeah, So 0:02:49.200 --> 0:02:51.480 to be on the podcast, we'll be tackling something that 0:02:51.520 --> 0:02:54.280 everyone has in their kitchens. So today on the program, 0:02:54.360 --> 0:03:02.640 we'll be asking the question how does a microwave work? 0:03:03.320 --> 0:03:06.440 Where I guess more specifically, how does a microwave oven work? 0:03:06.720 --> 0:03:08.720 You know what a microwave is. You put the stuff 0:03:08.760 --> 0:03:11.600 in there, you press the button, It spins, it beeps, 0:03:11.639 --> 0:03:15.600 it turns around, and it comes out hot. Right, But 0:03:15.680 --> 0:03:18.200 how does that actually happen? What's the physics that's going 0:03:18.280 --> 0:03:21.400 on there? Yeah? How do microwaves work? I mean, we've 0:03:21.400 --> 0:03:24.360 had them around for a long time. It seems right 0:03:25.280 --> 0:03:27.880 to heat up our foods are in our snacks, in 0:03:27.919 --> 0:03:30.519 our hot pockets. They first appeared in kitchens in the 0:03:30.639 --> 0:03:33.720 late fifties, I think, so it's been decades. Hatties around 0:03:33.720 --> 0:03:37.120 for a while, Yeah, And like many useful inventions, they 0:03:37.120 --> 0:03:40.680 were discovered by accident. They were discovered by a physicist 0:03:41.320 --> 0:03:44.920 poking around trying to do one thing, discovered something else useful, 0:03:45.120 --> 0:03:48.200 another way to save time. Right, for a lot of people, 0:03:48.280 --> 0:03:50.440 it's sort of it's sort of a convenience appliance. Like 0:03:50.480 --> 0:03:52.320 if you were to heat things up in the regular oven, 0:03:52.400 --> 0:03:55.040 it would just it would take much longer, but in 0:03:55.040 --> 0:03:58.480 a microwave, things seem to get hot really fast. Yeah, 0:03:58.520 --> 0:03:59.800 and you know, I don't want to take any of 0:03:59.800 --> 0:04:02.200 this the em out of this this podcast episode, but 0:04:02.240 --> 0:04:04.600 I'll admit that the microwave in our kitchen at home 0:04:04.640 --> 0:04:10.200 has been broken for about five years. And yeah, it's 0:04:10.280 --> 0:04:12.760 built into the double oven thing we have, so to 0:04:12.800 --> 0:04:15.320 get repaired, we have to replace the whole thing. So 0:04:15.360 --> 0:04:17.320 we just sort of put it off forever. And the 0:04:17.360 --> 0:04:20.360 truth is we haven't really missed it or never really noticed. 0:04:20.480 --> 0:04:24.560 You've lived without a microwave for five years. It is possible, people, 0:04:24.800 --> 0:04:27.080 you can live with that a microwave. Yes, it turns 0:04:27.120 --> 0:04:29.800 out you can make popcorn on the stove. So what 0:04:29.800 --> 0:04:31.560 do you use it for? It is like a storage 0:04:31.600 --> 0:04:35.640 You store some pots and dance in it or did 0:04:35.640 --> 0:04:37.839 you clean Did you clean it before you abandoned it? 0:04:37.880 --> 0:04:41.039 I wonder if you open this now, it's never been cleaned. No, 0:04:41.200 --> 0:04:44.760 you know our pet rats like to hang out in there. Um, okay, 0:04:44.800 --> 0:04:46.840 we don't use it for anything. It just uses up 0:04:46.839 --> 0:04:49.080 space in the kitchen. Wow, So you don't use a 0:04:49.120 --> 0:04:50.960 marc So if you have to heat up a quick thing, 0:04:51.040 --> 0:04:53.120 you just what do you do? You eat it cold? No, 0:04:53.240 --> 0:04:55.960 we got a toaster oven, We got an electric water kettle, 0:04:56.120 --> 0:04:59.240 We got a stove top that serves for mostly everything. Yeah, 0:04:59.520 --> 0:05:02.240 it turns out life is possible without a microwave. But 0:05:02.920 --> 0:05:05.640 it's a fascinating object in so many people's kitchen, and 0:05:05.760 --> 0:05:07.640 lots of people swear by it, so I thought it'd 0:05:07.680 --> 0:05:09.920 be interesting to dig into the physics of it. It 0:05:09.920 --> 0:05:13.239 turns out that very few people know how microwave works, 0:05:13.279 --> 0:05:15.559 and the people who think they know how microwave works 0:05:15.760 --> 0:05:18.800 probably have it wrong. Yeah. I was reading through these 0:05:18.839 --> 0:05:21.680 notes and I realized I have no idea how a 0:05:21.680 --> 0:05:24.479 microwave oven works. Or I thought I did, but it 0:05:24.520 --> 0:05:26.320 turns out that I that I don't, And so that 0:05:26.360 --> 0:05:28.320 sort of brings up an interesting question, like there's so 0:05:28.360 --> 0:05:31.560 many people out there who use a microwave. Almost nobody 0:05:31.600 --> 0:05:33.960 knows how it works. How come nobody seems to have 0:05:34.040 --> 0:05:36.520 spent any time thinking about it or wondering about it. 0:05:36.560 --> 0:05:39.039 Is it just physicists who want to understand, like how 0:05:39.040 --> 0:05:41.000 this stuff around us worked, and everybody else is sort 0:05:41.000 --> 0:05:43.320 of happy to just press a button and get their popcorn. 0:05:43.440 --> 0:05:46.000 I wonder if it's a generational thing. You know, at 0:05:46.080 --> 0:05:48.839 this point, most people grew up with the microwave. You know, 0:05:48.920 --> 0:05:51.520 it's sort of like, um, it's just there. It's like 0:05:51.560 --> 0:05:55.279 nobody sits around wondering how a refrigerator works or how 0:05:55.279 --> 0:05:58.760 a pencil works. You know. I think my kids ask 0:05:58.839 --> 0:06:01.320 me how refrigerators work. I want to know how things 0:06:01.360 --> 0:06:03.760 work that existed in the universe before I came to be. 0:06:03.920 --> 0:06:06.680 I'm not like big Bank. That's old news. I'm only 0:06:06.720 --> 0:06:10.520 interested in the news stuff. It's not trending, the big Bang, 0:06:11.160 --> 0:06:13.760 it's not trending. I don't care. So it's something that 0:06:13.839 --> 0:06:17.040 everyone is probably familiar with, and maybe most people own. 0:06:17.360 --> 0:06:19.359 But we were wondering how many people out there and 0:06:19.440 --> 0:06:22.640 know how a microwave actually works. That's right. So I 0:06:22.680 --> 0:06:26.000 walked around the streets of Aspen, Colorado, a place where 0:06:26.000 --> 0:06:28.159 people come from all over the world, with all sorts 0:06:28.160 --> 0:06:30.600 of different backgrounds. And I asked folks if they knew 0:06:30.680 --> 0:06:33.400 how a microwave work. The most people in Aspen, Colorado 0:06:33.480 --> 0:06:39.800 own multiple microwaves. They probably own multiple microwave companies, That's 0:06:39.839 --> 0:06:42.240 what I mean. And they say, I don't care as 0:06:42.240 --> 0:06:44.080 long as the share price keeps going up. Yeah, So 0:06:44.080 --> 0:06:45.520 I think about it for a second. If you were 0:06:45.520 --> 0:06:47.840 skiing out there and askm in Colorado and then a 0:06:47.880 --> 0:06:50.680 scruffy physicist asked you, hey, how does the microwave work? 0:06:50.960 --> 0:06:53.200 What do you think you would answer? Here's what people 0:06:53.200 --> 0:06:59.000 had to say, best guess microwaves electricity fastened through food. No, 0:07:00.200 --> 0:07:06.360 electricity turned into something genetically modifies your food? Yeah, has 0:07:06.520 --> 0:07:08.960 right onto, right on too? And how does that eat 0:07:09.040 --> 0:07:11.760 up your food? The moistation of food is what calls 0:07:11.840 --> 0:07:23.800 the uh yes electricity, the Mormon quality. Can you find 0:07:23.800 --> 0:07:30.960 that jet English? Something around electricity coming down in waves? 0:07:31.440 --> 0:07:37.680 You say, start and then what happens microwaves? No, I 0:07:37.720 --> 0:07:39.720 do not know. Do you know how a microwave works? 0:07:40.400 --> 0:07:45.720 I do, Oh, how it works? Maybe not? We pressed 0:07:45.720 --> 0:07:49.560 plus through a second bottom then start, all right. It 0:07:49.600 --> 0:07:53.160 seems that those microwaves company owners in Asthment don't really 0:07:53.160 --> 0:07:56.640 have much of an idea of how they work. Well, 0:07:56.680 --> 0:08:00.920 I was amazed at the huge variety of answers. I mean, 0:08:00.960 --> 0:08:06.120 we got radiation, we got genetic modification to the foods um. 0:08:06.160 --> 0:08:08.720 There's that one guy who seemed to understand how microwave worked, 0:08:08.720 --> 0:08:13.960 but he could only explain it in Japanese to his wife. Well, 0:08:14.000 --> 0:08:15.920 that's the same with me. I I know how it works, 0:08:15.920 --> 0:08:20.080 but I only know how it works in Japan. I 0:08:20.120 --> 0:08:22.000 like the guy who said, how does the microwave work? 0:08:22.040 --> 0:08:24.520 You just press the start button. That's how it works, right, 0:08:24.800 --> 0:08:27.200 I know. Like I was asking for tips, like help, 0:08:27.400 --> 0:08:29.080 I need to use the microwave and I don't know 0:08:29.080 --> 0:08:32.760 how it works. Please give me tell me my food 0:08:32.840 --> 0:08:35.680 is cold, Like I'm out here on the street with 0:08:35.720 --> 0:08:41.920 my recorder looking for tech support from my microwave. Well 0:08:42.040 --> 0:08:45.720 he would have been helpful. Yeah, yeah, and uh, and 0:08:45.760 --> 0:08:47.680 you know, and you heard a couple of people say 0:08:48.280 --> 0:08:49.960 what I think is a common trope, which is that 0:08:50.520 --> 0:08:54.360 the microwave heats up the water, right, which I think 0:08:54.440 --> 0:08:57.760 is a common misunderstanding. We'll get into it later, but 0:08:57.840 --> 0:09:01.320 that's not how a microwave works, right, Yeah, that's what 0:09:01.360 --> 0:09:04.200 I thought too. And also some people said it has 0:09:04.400 --> 0:09:10.320 with electricity, like somehow it uses electricity to zap your food. Yeah, 0:09:10.360 --> 0:09:12.800 and you know it does use electricity. It's not like 0:09:12.840 --> 0:09:18.480 it's a coal powered microwave or something steampunk steampunk microwave, 0:09:20.240 --> 0:09:24.200 like you have all the steam, but you converted to microwaves. Yeah, 0:09:24.320 --> 0:09:25.959 somebody out there probably has done that, you know. On 0:09:26.080 --> 0:09:30.400 a recent episode about gravitons, I wondered out loud what 0:09:30.480 --> 0:09:33.520 a gravitron was, and that moment in our podcast I 0:09:33.559 --> 0:09:36.319 think might have generated the most listener response because I 0:09:36.400 --> 0:09:39.319 got dozens of emails from people who had written in 0:09:39.400 --> 0:09:43.439 their childhood a gravitron an amusement park ride. So that 0:09:43.520 --> 0:09:46.960 generated the most the most emails of anything we've ever 0:09:47.040 --> 0:09:48.959 done so far. Actually know that, because that was on 0:09:49.040 --> 0:09:52.280 the latest season of Stranger Things. Yes, you're right, there 0:09:52.320 --> 0:09:55.400 was a scene in the gravitron Um. So if anybody 0:09:55.480 --> 0:09:59.440 out there knows of a coal powered microwave, please right 0:09:59.559 --> 0:10:01.000 in and say, d as a picture. I'd love to 0:10:01.040 --> 0:10:03.280 see it. Well, so, um, not a people. A lot 0:10:03.320 --> 0:10:05.720 of people know how a microwave works, and I didn't 0:10:05.760 --> 0:10:08.959 know apparently how a microwave works, so let's get into it. 0:10:09.360 --> 0:10:12.720 But maybe first what you talked about how normal ovens work, 0:10:12.840 --> 0:10:15.760 like the ones with gas or the ones that are electric, 0:10:15.960 --> 0:10:19.440 not the microwave kind. So a normal oven basically works 0:10:19.520 --> 0:10:22.480 by heating the air inside the oven, and then the 0:10:22.600 --> 0:10:25.880 air heats your food, right, And that's you'll notice this 0:10:25.960 --> 0:10:27.679 because if you open a normal oven, you get like 0:10:27.760 --> 0:10:29.840 a rush of hot air that comes out and burns 0:10:29.880 --> 0:10:32.160 your face, right, Whereas if you open a microwave, you 0:10:32.240 --> 0:10:34.800 don't notice that. In a regular oven, you you rely 0:10:35.160 --> 0:10:36.959 you like, you put the energy into the air, and 0:10:37.000 --> 0:10:39.800 then you rely on the air to give the energy 0:10:39.880 --> 0:10:42.760 to your food. That's right. And remember, on a microscopic level, 0:10:42.840 --> 0:10:45.640 what's happening is that the air is heating up, and 0:10:45.720 --> 0:10:49.000 that means that the air molecules are getting faster. Right. 0:10:49.480 --> 0:10:52.600 We talked about temperature in another episode. Sort of crazy concept, 0:10:52.640 --> 0:10:55.320 but the simplest idea is that you're just speeding up 0:10:55.440 --> 0:10:58.040 the air molecules, so they're zooming around faster and faster 0:10:58.520 --> 0:11:01.880 inside the oven, and sometimes they bounce into your food 0:11:02.240 --> 0:11:04.719 and they deposit some energy, so they heat up the 0:11:04.760 --> 0:11:08.040 molecules in your food. Right, maybe your oven is gas 0:11:08.120 --> 0:11:10.720 and his little flames or it has heating element if 0:11:10.720 --> 0:11:13.640 it's an electric oven, and that heats up the air, right, 0:11:13.679 --> 0:11:16.679 which speeds up those molecules, and they bounce into the 0:11:16.800 --> 0:11:19.959 molecules of your food and heat them up. Yeah, when 0:11:20.000 --> 0:11:22.760 you put it like that, it seems really inefficient to 0:11:22.880 --> 0:11:26.280 think about ovens like that. The air and then the 0:11:26.360 --> 0:11:27.800 air you have to wait for the air to bump 0:11:27.840 --> 0:11:31.600 into your food, and then it only bumts into the surface, right, 0:11:31.640 --> 0:11:35.800 the outer skin of your food. So that's why it 0:11:35.840 --> 0:11:37.600 takes a while to heat up in a regular oven, 0:11:37.960 --> 0:11:40.080 that's right. And they're super inefficient in my house because 0:11:40.120 --> 0:11:42.360 every time I'm baking something, somebody will walk by the 0:11:42.400 --> 0:11:45.240 oven every five minutes and open it up. What's in there, 0:11:45.480 --> 0:11:47.440 and then all the hot air rushes out and you've 0:11:47.440 --> 0:11:50.400 got to heat up the whole oven again. I'm surprised 0:11:50.400 --> 0:11:53.959 you're a regular oven works, Daniel. I'm gonna put a 0:11:54.040 --> 0:11:57.360 lock on it or something. But yeah, that's over camp 0:11:57.440 --> 0:12:01.840 fire every night. That things exactly why. Um, that's exactly 0:12:01.880 --> 0:12:04.200 why the food in your oven heats from the outside 0:12:04.240 --> 0:12:06.400 in because the outside is the only part exposed to 0:12:06.480 --> 0:12:09.240 the air. Right, So the outside of your food, the 0:12:09.240 --> 0:12:11.920 outside layer gets heated by the air, and the inside 0:12:12.000 --> 0:12:15.000 gets heated by the outside. Like you're cooking the turkey, 0:12:15.480 --> 0:12:17.800 the skin gets hot first, and then the heat of 0:12:17.840 --> 0:12:20.839 the skin cooks the next layer, and that layer cooks 0:12:20.840 --> 0:12:22.840 the next layer, and that layer cooks the next layer. 0:12:23.160 --> 0:12:26.440 So it's sort of like heat propagating through the turkey, 0:12:26.520 --> 0:12:29.520 but has to start from the outside. That's the hottest part, right, 0:12:29.600 --> 0:12:32.000 And that's kind of then that's kind of good sometimes 0:12:32.040 --> 0:12:35.360 because that's where you get you know, crunchy crusts. Yeah, exactly, 0:12:35.920 --> 0:12:37.880 you get this browning effect from the hot air, and 0:12:37.960 --> 0:12:39.959 that's because the air can get to a sort of 0:12:40.040 --> 0:12:43.040 a high enough temperature to be like caramelization, and that 0:12:43.160 --> 0:12:45.600 gives you the good browning stuff. And you know, sometimes 0:12:45.640 --> 0:12:47.880 you want that. You want the outside to be crunchier 0:12:47.960 --> 0:12:50.199 and hotter than the inside. Like for a turkey, you 0:12:50.280 --> 0:12:52.079 don't want the breast meat to get up to a 0:12:52.120 --> 0:12:54.040 certain temperature because then it gets dry, but you do 0:12:54.200 --> 0:12:56.760 want the outside of a higher temperature. So for things 0:12:56.800 --> 0:12:58.920 where you want the outside hotter and the inside a 0:12:59.000 --> 0:13:02.079 little bit cooler, a convection of it is perfect, Okay, 0:13:02.160 --> 0:13:05.040 So it doesn't sound super efficient, but it's an old, 0:13:05.160 --> 0:13:08.320 old timey trusted technology we've been doing. We've been using 0:13:08.360 --> 0:13:11.559 ovens for thousands and thousands of years. It doesn't break down, 0:13:14.200 --> 0:13:16.679 that's right. I mean in the old days, before we 0:13:16.760 --> 0:13:19.280 had gas ovens and electric ovens, an oven it was 0:13:19.400 --> 0:13:22.080 just like an enclosed space with a bunch of burning 0:13:22.120 --> 0:13:24.000 wood in it. Right, And people still do that, like 0:13:24.080 --> 0:13:26.120 a pizza oven. Right, you can get up to eight 0:13:26.240 --> 0:13:28.839 hundred degrees or nine degrees, and you see these things, 0:13:28.920 --> 0:13:30.880 they're just like they got wood burning in the back. 0:13:31.160 --> 0:13:33.280 And it's just an enclosed space to trap the heat. 0:13:33.559 --> 0:13:35.760 Because if you have a fire without walls around it, 0:13:35.800 --> 0:13:37.839 then the heat just rises and you can cook over it, 0:13:38.080 --> 0:13:40.520 but it's much less efficient. So you just enclose it 0:13:40.600 --> 0:13:43.200 to sort of capture the heat um where you are. 0:13:43.320 --> 0:13:45.199 And that's that's an oven. That's all an oven is 0:13:45.280 --> 0:13:47.559 is a heat source and something to capture it to 0:13:48.040 --> 0:13:50.920 the air stays hot. All right, that's how normal ovens work. 0:13:51.320 --> 0:13:54.199 So let's get into microwaves. But first let's take a 0:13:54.280 --> 0:14:09.880 quick break. All right, we're talking about microwave ovens and 0:14:09.920 --> 0:14:12.480 how they work. So Daniel break it down for us 0:14:12.679 --> 0:14:16.000 how does a microwave oven work? Well, maybe we first 0:14:16.040 --> 0:14:17.800 we should figure out we should talk about what a 0:14:17.920 --> 0:14:21.320 microwave is, right, Like, what is this thing? We tackled 0:14:21.360 --> 0:14:25.480 the word oven, now we're tackling the word microve waves. Right, 0:14:25.600 --> 0:14:27.720 but first let's break it that into micro m wave. 0:14:28.760 --> 0:14:31.800 What is the letter N really means? What is letter I? 0:14:33.440 --> 0:14:37.560 Three hours later we'll get to the answer. It's pretty simple. Actually, 0:14:37.640 --> 0:14:40.520 a microwave is just a kind of light. Right. Remember 0:14:41.160 --> 0:14:45.600 that all these things gamma rays, X rays, UV light, 0:14:45.800 --> 0:14:48.960 visible light, um, radio waves, these are all just parts 0:14:49.000 --> 0:14:51.920 of the electro magnetic spectrum. It's not like a special 0:14:52.120 --> 0:14:55.120 kind of ray or a special kind of particle, or 0:14:56.160 --> 0:15:00.280 you know, laser is just plan o light. It's just 0:15:00.400 --> 0:15:05.440 plain old electromagnetic radiation, right, And a microwave just refers 0:15:05.480 --> 0:15:08.760 to the wavelength of that radiation. So remember, the thing 0:15:08.840 --> 0:15:13.400 that differentiates a gam array from ultraviolet light, from visible light, 0:15:13.560 --> 0:15:17.000 from X rays or radio waves is just the frequency 0:15:17.200 --> 0:15:20.440 of the wiggling. Right. All these things are electromagnetic fields 0:15:20.520 --> 0:15:23.040 oscillating up and down and left and right, and the 0:15:23.160 --> 0:15:25.760 speed at which they oscillate, how many times they oscillate 0:15:25.840 --> 0:15:30.320 per second, right, or equivalently, the wavelength of their oscillation, right, 0:15:30.360 --> 0:15:34.040 how long that wave is UM determines which one it is. 0:15:34.480 --> 0:15:36.680 And so radio waves are the ones with a really 0:15:36.800 --> 0:15:40.200 long wavelengths, Like there are radio waves that have lengths like, 0:15:40.360 --> 0:15:44.200 you know, dozens and dozens of meters. Microwaves. It's sort 0:15:44.200 --> 0:15:47.960 of a confusing name because microwaves are radio waves with 0:15:48.360 --> 0:15:52.640 shorter wavelengths, so down about twelve centimeter. But it's only 0:15:52.720 --> 0:15:55.600 shorter compared to radio waves, which have like dozens of 0:15:55.720 --> 0:16:00.200 meters of wavelength. They're not short comparable light visible, they're 0:16:00.240 --> 0:16:04.520 not like nanometers, they're not microscopic, that's right, They're only 0:16:04.640 --> 0:16:09.160 micro compared to really big radio waves. Oh scale thing. Huh. 0:16:09.280 --> 0:16:13.160 But so they're microwaves are actually like megawaves compared to 0:16:14.400 --> 0:16:17.720 like the visible light that we all see every day, yeah, 0:16:17.760 --> 0:16:21.000 which is wavelengths of like hundreds of nanometers, which is tiny, right, 0:16:21.320 --> 0:16:24.120 These things have wavelengths that are in the twelve centimeters. 0:16:24.200 --> 0:16:26.080 That's you know, the size of your hand or something 0:16:26.160 --> 0:16:29.840 like that. So these things have real physical wavelength Wait 0:16:29.880 --> 0:16:32.080 are you telling me that physicists names something in a 0:16:32.160 --> 0:16:36.960 confusing way? What are you telling me that you're surprised 0:16:37.320 --> 0:16:42.400 that physics name would be confusing. Touche touche. Anything named 0:16:42.400 --> 0:16:45.480 in the pre Jorge epoch is defined to be confusing 0:16:45.480 --> 0:16:50.360 because you were not involved. Yeah, yeah, the PJ. We 0:16:50.440 --> 0:16:52.120 don't like to talk about it. You know, it's a 0:16:52.200 --> 0:16:56.320 dark period in the history of physics, but it does exist. Okay, 0:16:56.360 --> 0:16:59.120 so they're they're microwaves, but they're not really micro they're 0:16:59.120 --> 0:17:02.800 actually like, you know, twelve centimeters. It's sort of like 0:17:02.920 --> 0:17:06.639 the length of your hand. Yeah, yeah, exactly, And so 0:17:06.920 --> 0:17:09.359 that's what a microwave is. And then you might wonder, like, 0:17:09.680 --> 0:17:12.200 all right, but you know, how does that heat my food? 0:17:12.280 --> 0:17:15.560 If I shine my flashlight at a turkey, it doesn't 0:17:15.600 --> 0:17:20.760 cook it, right, not, Well, it depends on your flashlight, 0:17:20.800 --> 0:17:25.000 doesn't it. If your flashlight is the large Hadron collider, 0:17:25.040 --> 0:17:28.800 then yeah, maybe, yeah, that's what I mean. It's it's 0:17:29.880 --> 0:17:32.200 it's it's not that the regular light doesn't cook, it's 0:17:32.240 --> 0:17:34.360 just that it doesn't cook as well. Yeah, that's true. 0:17:34.440 --> 0:17:36.600 It does deposits of energy, it just doesn't have that 0:17:36.720 --> 0:17:39.399 much energy on it. But it's essentially the way a 0:17:39.480 --> 0:17:42.399 microwave oven works is that it blasts your food with 0:17:42.760 --> 0:17:46.879 marcro wave radiation, right, which, again, radiation, It sounds scary, 0:17:46.960 --> 0:17:49.520 but it's really just light. Yeah, light is an example 0:17:49.600 --> 0:17:52.679 of radiation. So this is just another kind of electromagnetic radiation. 0:17:53.320 --> 0:17:55.920 And and you might be wondering like, well, okay, why 0:17:56.040 --> 0:17:59.199 does this specific frequency of radiation tend to heat at 0:17:59.200 --> 0:18:01.239 your food? Why is that do that? Right? Well, one 0:18:01.280 --> 0:18:04.320 thing you'll notice is that when you open up a 0:18:04.440 --> 0:18:07.040 microwave oven after you've cooked your food, right, that the 0:18:07.200 --> 0:18:10.159 air inside the microwave oven is not hot. So a 0:18:10.240 --> 0:18:12.920 lot of people think that the way a microwave works 0:18:13.480 --> 0:18:16.720 is that the microwave radiation heats up just the water 0:18:16.960 --> 0:18:20.120 inside the food. Yeah, I've heard, I've heard of that. Yeah, 0:18:20.560 --> 0:18:23.080 Like somehow there's something like it only heats up the 0:18:23.119 --> 0:18:27.160 water molecules, or preferentially the water molecules in your food. 0:18:27.840 --> 0:18:29.200 That's kind of why. I like, if you stick a 0:18:29.400 --> 0:18:31.480 plastic plate, it's not going to heat up as much 0:18:31.520 --> 0:18:34.760 as if you put you know, a hot dog, mhmm. 0:18:34.880 --> 0:18:37.240 And there is some truth to that, right, A microwave 0:18:37.280 --> 0:18:39.640 will heat up some kinds of food more than other 0:18:39.720 --> 0:18:42.240 kinds of food. But the reason that some people give 0:18:42.640 --> 0:18:46.240 is that they think that microwave has like a resonant 0:18:46.359 --> 0:18:50.280 frequency with the water. Remember, microscopically, water is made out 0:18:50.320 --> 0:18:53.080 of molecules, and those molecules can do things like spin 0:18:53.280 --> 0:18:57.160 and vibrate, and like all atomic stuff, it's quantum mechanical, 0:18:57.280 --> 0:19:01.119 which means it can only accept um radiation. It's certain frequencies. 0:19:01.400 --> 0:19:04.440 Like we talked about how atoms can absorb wavelength certain 0:19:04.480 --> 0:19:07.240 wavelengths of light and not other wavelengths of light. So 0:19:07.440 --> 0:19:09.840 some people, I think, imagine that this is what's happening 0:19:09.880 --> 0:19:12.720 instaide your microwave. That water can absorb frequency at this 0:19:12.800 --> 0:19:16.119 wavelength um and the air and the other stuff can't. Right, 0:19:16.240 --> 0:19:19.120 So that's the common misconcept. And when you say resonant 0:19:19.400 --> 0:19:22.520 frequency mean like kind of like a water the idea 0:19:22.560 --> 0:19:25.399 that water has kind of an internal bouncing nous to it, right, 0:19:25.560 --> 0:19:29.480 like an internal m M like frequency. It likes to 0:19:29.560 --> 0:19:33.160 bounce around like a guitar string. Yes, exactly, And it's 0:19:33.160 --> 0:19:36.160 true of every atom, right, they do have special frequencies 0:19:36.560 --> 0:19:38.440 at which they like to vibrate. And it depends on 0:19:38.520 --> 0:19:40.280 the atom and how it's built and how the electrons 0:19:40.320 --> 0:19:42.440 are organized and all that stuff, and so they do 0:19:42.600 --> 0:19:46.040 have special resident frequencies that they do like to absorb radiation. 0:19:46.320 --> 0:19:48.760 But that's not what's happening here. That's not the way 0:19:48.800 --> 0:19:52.159 that the microwave work. It's not it's not definitely not No, 0:19:52.320 --> 0:19:56.240 it's a totally different but really fascinating mechanism. You just 0:19:56.440 --> 0:20:01.040 nuke my brain here, I just reard my start my 0:20:01.160 --> 0:20:04.520 illusion of understanding here. Okay, so it's not making a 0:20:04.600 --> 0:20:06.800 residence with the water, So how is it? But it is? 0:20:06.920 --> 0:20:08.880 It is sort of related to water, right, Like, there's 0:20:08.920 --> 0:20:13.200 something about water molecules that microwaves are kind of specially 0:20:13.320 --> 0:20:18.040 tuned to a heat up. Yeah, and it's a different process. 0:20:18.119 --> 0:20:22.600 It's called dielectric heating. Essentially. It's because water molecules they 0:20:22.680 --> 0:20:25.560 have the same number of positive and negative charges, but 0:20:25.640 --> 0:20:28.960 they're not exactly balanced in the same place, right, which 0:20:29.040 --> 0:20:31.399 means that one part of the water molecule is a 0:20:31.440 --> 0:20:34.600 little more positive and another part is a little more negative. 0:20:34.760 --> 0:20:37.240 So overall there's a little bit of a separation of 0:20:37.320 --> 0:20:40.119 the charges. So what happens when electroc one side of 0:20:40.119 --> 0:20:44.760 water is more optimistic dealing, what's more pessimistic. That's right, 0:20:44.800 --> 0:20:48.359 You got the upside and the downside. Um somewhat some 0:20:48.480 --> 0:20:51.800 water molecules are like the glasses have full of us. 0:20:52.720 --> 0:20:55.479 They have just like this glasses have empty of us. 0:20:55.840 --> 0:21:00.199 It's a big But what happens when electromagnetic waves by, 0:21:00.280 --> 0:21:04.360 Remember electromagnetic waves interact with things that have charge, right, 0:21:04.560 --> 0:21:07.159 negative and positive charge, and so what they do is 0:21:07.200 --> 0:21:09.800 that one part of the molecule gets pushed one way 0:21:09.920 --> 0:21:11.720 and the other part that has the other charge gets 0:21:11.760 --> 0:21:15.160 pushed the other way. You're saying, like a water molecule 0:21:15.280 --> 0:21:17.560 is kind of like a little magnet where one end 0:21:18.119 --> 0:21:20.960 is sort of negative and the other side is positive. 0:21:21.080 --> 0:21:24.120 So it's not like perfectly even, yeah, it's not. It's 0:21:24.200 --> 0:21:26.360 kind of like a magnet in that there are north 0:21:26.440 --> 0:21:28.120 and south, right, But in this case we're talking about 0:21:28.119 --> 0:21:31.320 electric charges and they're positive and negative, and the waves 0:21:31.359 --> 0:21:33.040 come by and they tweak it, and they tweak it 0:21:33.080 --> 0:21:35.520 differently because the charge is different on one side than 0:21:35.560 --> 0:21:38.879 the other. Right, it's overall neutral, but you've separated the 0:21:38.960 --> 0:21:41.320 charges a little bit so that you have a positive 0:21:41.359 --> 0:21:44.240 and negative and so the wave gives the two sides 0:21:44.280 --> 0:21:47.280