Episode Transcript Arpita: 0:10 Hi everyone. And welcome back to the Smart Tea podcast, where we talk about the lives of scientists and innovators who shape our world. How are you, Aarati? Happy Friday! Aarati: 0:20 Yeah, happy Friday, Arpita. I'm doing pretty well. Um, I'm tired. I'm just, it's been a week. It's been a long week, and I'm so glad we have the three day weekend coming up. Arpita: 0:31 Yeah, I am right there with you. We were supposed to record yesterday and I frantically texted Aarati being like, can we please reschedule? I've had such a busy week at work and I was scrambling to meet a deadline yesterday and I was like, there is no way I can get my act together in the next 30 minutes as planned. So... Aarati: 0:53 I know how it is. Arpita: 0:54 But yeah, agree with you. It has been quite a week. My only agenda item for the next 3 days is to not leave my couch and I can't Aarati: 1:04 Good. Arpita: 1:05 wait. This year has been so busy. Um, we have had...eight weddings, uh, including my own, Aarati: 1:14 Including your own, yeah. I was gonna say. Arpita: 1:16 and had just like a ton of travel in between that. And so it's like, all like, really good things, like, all really fun things and like, very exciting things. But it's just like, I'm just so tired. Work has been really busy and just I feel like I'm coming home. Unpacking my suitcase and then like so quickly after just pulling my suitcase back out and repacking it. Um, Which is like, again, like it just all really wonderful, fun things, but also just like so tiring after a while. And Aarati: 1:48 Yeah. Arpita: 1:49 anyway, so that's where I'm at and I just cannot wait to Aarati: 1:52 Yes. Arpita: 1:53 not leave my couch this weekend. Aarati: 1:55 sounds like a good plan. I like it. We have kind of, the opposite thing happening where I'm not going anywhere, but a lot of people are coming to our house. And so we're like constantly entertaining. So like last weekend, uh, my aunt and uncle from Singapore were here and it was just, You know, like how Indian people do when you have guests over. It's like, we have to cook all the food. Yeah. We have to clean the whole house. We have to cook all the food. And, um, right now my room is kind of like the nicest room. So it's now become the slash guest bedroom room in the house. So I ended up getting kicked out of my own room so I can sleep on the couch. Arpita: 2:35 dear. I feel like that's like a such a specific brand of stress too and it's like there's one thing where you're leaving your home, but there's also this like this is your space and it's now no longer your space and then the production value of like Indian families visiting. You're just like, Oh, this is what our house looks like all the time. You're just like, Oh, welcome. It's like, this is what it always looks like. Aarati: 2:58 Everything. And then it's even worse, because like, they're in my bedroom, so I'm like, you know, Okay, my bedroom is always immaculate. Yes. My, it always looks like a hotel room. Absolutely. Arpita: 3:09 There's always mints on the pillows. Aarati: 3:11 G et the dog smell out of my room. Arpita: 3:14 Yeah, how is Kyro doing with all the guests? Aarati: 3:16 Oh, he loves them. He loves having people over. It's like his favorite thing in the world. It's kind of hard because sometimes they're a little bit scared of him because he's so big, um, and they're just like, oh, I don't know about this big, scary, German shepherd looking dog that's coming at me, you know? And I'm like, he's coming at with you with love, like you gotta just get in there, pet him, and then he'll calm down. And he's so happy to see guests though, and by the end of it. They're all like really impressed by him. They're like, Oh, he's so loving and he's so calm. And I'm like, yeah, you just give him a chance. Arpita: 3:54 He is. I get that though, if you're like, not used to dogs, or like, you haven't spent a lot of time around dogs, like, he is big and excited. he's big. and he's excited. So he's like running at you like hello. I love you be my friend. Aarati: 4:09 And then when they leave, he's so sad. He like hangs his head and he looks at you like, are you seriously abandoning me right now? Like, Arpita: 4:18 My heart. Aarati: 4:19 Even if they've been there for only three hours or something, like, you know, my, my aunt and uncle stayed for a couple days, but, like, even guests that stay for three hours, he's like, is the party over already? Oh, man. So, Arpita: 4:32 He's like all my friends are leaving. Aarati: 4:34 yeah, exactly. So, yeah, he, he loves it though. So, um, he's happy with everything. He's happy when we have guests over. So, he's a pretty chill dog. Arpita: 4:44 Oh, yeah, he's cutie. Aarati: 4:46 Yeah, um, in podcast news, I wanted to tell you, we got our first, like, written review on Apple Podcasts. Arpita: 4:55 Wait, did we really I did not see this. Aarati: 4:58 We did! And this is what kicked off my whole, like, motivational push to get a little, short video out on, Tiktok and on YouTube. So I've started a YouTube channel, I've started a TikTok channel for our podcast solely because of this review because it like motivated me so much. But it's like by somebody named smnumber1. And they gave us five stars. And they wrote, Albert Hoffman and Emmy Noether episodes were great. Now I'm listening to the first dinosaur fossil episode. And I'm pleasantly surprised to hear Auburn mentioned in the beginning as I grew up in Placer County and absolutely love Auburn. Will be sharing with friends. Arpita: 5:42 Amazing Aarati: 5:43 and it's highly motivational, so please, if you listen to this podcast and you like it, please leave us a review, we love it. Arpita: 5:49 I loved it. It was great news. And we also got our thousandth download, didn't we? Aarati: 5:54 Yes, we did, yes, we did, a lot of milestones that we're achieving, Arpita: 5:58 Big milestones, yeah. On that note, who are we talking about today, Aarati? Aarati: 6:03 Today we are talking about Percy Spencer who is the inventor of the microwave. Arpita: 6:11 Whoa, fun. I'm excited. I use my microwave a stupid amount, so I can't wait. Aarati: 6:16 I know, right? Me too. And I was like, I actually don't know how microwaves work. And I know there's a lot of stuff about, are microwaves dangerous? And do they, you know, hurt the nutritional value of food? And can you get radiation? And there's all this stuff. And I'm like, I don't actually know anything about microwaves. So let's do, Percy Spencer, who invented the microwave, and learn about it a little bit. Arpita: 6:40 I can't wait. My husband's favorite cooking method is to put it in the microwave. Like his, if he's cooking dinner, he is not using the stove. He's using the microwave. Aarati: 6:49 Oh, really? Like a fully microwaved meal? Arpita: 6:51 Fully microwaved meal. He's like microwaved blocks of tofu. He's microwaved tortillas. He's microwaved everything. Aarati: 6:59 I don't know if I told you this, but my grandma's living with us now. Arpita: 7:02 Yeah. Yeah. Aarati: 7:04 And she's completely the opposite. She like, she's like, what is this device? A microwave? Like, no, everything must be freshly cooked. And there's no such thing as meal prepping with her. She makes exactly the amount of portions that, you know, the family needs. And if it's not finished by the end of the meal, she's highly stressed out, like who's going to finish this old rice or this Arpita: 7:26 Because it doesn't go in the fridge? Aarati: 7:27 Yeah, it has to go in the fridge and you have to microwave it No, just finish it now while it's fresh. Arpita: 7:34 This feels like such a,, like, Indian grandma thing to do, like, extremely, I had this we're on a tangent, but this is related. I promise. Um, I knew this guy in college who was like, from a very well off family, and they had a cook, who lived with it or like whatever. And this cook would always make him fresh food every day, and he never had to like cook. Put away leftovers or whatever. Like the end of the meal, was just like, he was done and he would like leave the table and that would be the end of the story for him. And so when he got to college, many of us, you know, we would go, if we went and got dinner, we would all get takeout boxes and then take it home to eat, which I'd still do, I just want to, I just want to like, we do not throw away the food that is Aarati: 8:21 don't throw away. Arpita: 8:21 incorrect. You've never throw away the food. Yeah. You never throw away the food. You have to take it home, but he would just leave it. Ever. He would like give us his leftovers and he was of the same mindset where he basically said, I only eat fresh food and this will no longer be fresh. And we were just like, are you joking? Aarati: 8:39 you kidding? Yeah. Oh my god. It's like a different tax bracket entirely. Arpita: 8:46 just like a different, like, like I don't even. I have a hard time with leaving food on my plate to go and, like, if it's still on my plate and I can't finish it, it's going in the fridge. Like, that's the only option. Like, putting it in the trash is not an option unless it's actively bad. Like, it's moldy or like, something like that. Aarati: 9:05 Yeah, exactly. I'm the same exact way. And sometimes I even order food knowing that I'm not going to be able to finish it all. And so that kind of like dictates what I'm going to order because I'm like, oh, if I get like a salad or something that has lettuce in it or something like that. It's not going to be as good the next day. So I'm not going to get that reheat it in the microwave. And so it's like, it's a whole process, you know, it's Arpita: 9:30 Or, or I will like justify the price of something. So it's like a really big bowl or something is$15. I'm like, actually, this is only$7.50 because I'm going to eat it twice. Aarati: 9:40 Yes, exactly. Oh my gosh. Yes. It's so, it's so true. Yeah. The microwave is just indispensable. Arpita: 9:48 The way that we live our lives. Yeah. I can't wait to hear about it. Aarati: 9:52 Okay. So, Percy LeBron Spencer, was born in Howland, Maine, on July 9th, 1894, Some sources say he was born on the 19th, but I read an article by Monica M. Smith, who wrote a piece for the Smithsonian where she literally just went through and looked at publicly available government records, like military and U. S. Census records, and she confirmed certain dates and details about his life. So if there was ever any, like, discrepancy online about the dates that things happened, I'm just going with what she said. Arpita: 10:26 Yeah. Aarati: 10:28 Um, so Percy was born to Jasper and Myrtle Spencer, and he had one older brother called John Alby, who was nicknamed Al. We don't know a lot about his parents, because when Percy was 18 months old, his father died, and his mother sent Percy to live with his aunt and uncle. I'm not really sure what she did with Al because it kind of sounds like their mom basically abandoned them both and the two brothers got separated. Like, it doesn't sound like they ended up living together. But they were still very close, even, even though they weren't living together, they still like stayed in touch and even lived together as adults at one point. Arpita: 11:07 Did they get raised by family members? If the mom left them? Aarati: 11:10 I'm guessing? Like, Percy definitely was raised by his aunt and uncle. Um, Al, I don't know where he went. So I don't know what happened to him, but it didn't sound like on based on the research that I was reading, it didn't sound like they both went to the aunt and uncle. It sounded like Al went somewhere else, maybe, maybe to some other family members or friends or something. I don't know, but it does sound like they got, you know, separated. a bit. Arpita: 11:35 Wait, sorry. What happened to the mom though? She just, she abandoned them. Aarati: 11:38 just, yeah, she just bounced. She was like, okay, bye. I'm not doing this... Arpita: 11:41 Okay, and we don't really know what her story is. Aarati: 11:44 Yeah. Arpita: 11:45 We don't, we don't really know. Um, so like that's, that's basically all we know about her parents is that father died and mom said, I'm out. And so he was basically orphaned when he was like 18 months old or something, so, his Al went on to actually be an inventor himself. He invented something called the Spencer disk, which was also known as a Klixon and basically it's a circuit breaker that switches off the electricity when things get too hot inside of a machine. So it acted a lot like those, I don't know if you've played with those like curved rubber disc toys that you kind of like flatten or you turn inside out and you put it on a flat surface and after a few seconds it like shoots up in the air. And returns back to its original position, and you keep doing that. Have you ever played with those as a kid? Is it the thing that you turn inside out and then you put it down and then it pops? Yes. Yes. Yes. Yes, I do know what you're talking about. Aarati: 12:47 yeah. So that's basically, like, what a Klixon is. It's like a curved disc that's part of an electric circuit, and so electricity is running through it, and when it gets too hot, the disc reverses its curvature. Yeah. And it breaks the electric current, so that the electricity shuts off. Arpita: 13:03 That's very simple. I like that. Aarati: 13:05 Yeah very simple. And it was very valuable because it helped prevent a lot of fires. But, um, Al never became as famous as his brother, Percy. But later, Percy's grandson said that Percy would always carry a Klixon in his pocket. And as soon as someone asked him, What's in your pocket? He would whip it out and demonstrate how it worked. So, he was like, Yeah, really proud of his brother. Okay, but back to Percy who's still a child being brought up by his aunt and uncle. When Percy was seven, his uncle, who's basically now his father figure, also died. And, this is extremely hard on his aunt because they were already poor to begin with. So Percy started helping with as many chores as he could and learned how to chop wood, skin a deer, preserve meat, and many other like very survival type things, and he credits this with helping him develop what he called a Yankee mentality of just like making things work somehow with whatever he was able to get his hands on. Arpita: 14:11 This feels very, this feels like the quintessential Americana, like pull yourself up by your bootstraps, which for the record, I not necessarily agree with, but I just, it does feel like that. Aarati: 14:22 It is very much. It's just like, what do you have? How do you put it to the best possible use, and survive and make it happen? And this was how he was able to come up with his innovations in science also later, which we will see. So at the age of 12, Percy drops out of school and he starts working at a spool mill to make money to support him and his aunt. So he basically becomes a 5th grade dropout and he never formally goes back to school, ever. Like, that was it. Arpita: 14:54 Wow. It's such a difference from a lot of the other people we've talked because even though a lot of other people had similar upbringings, many of them became the generational breakers where they were the first ones to go to college or the first ones to become educated or, you know, pave this path. But it is interesting that he never actually did go back to school. So Aarati: 15:15 Yeah. He never, yeah, he never got a formal education after that. He just, and he couldn't, I was like, what a burden that must have been to be 12 years old and have to work full time to support yourself and your aunt. L ike, that's crazy to me. But he was a very intensely curious person and he was always trying to figure out how things worked. Arpita: 15:40 Mm hmm. Aarati: 15:41 And so case in point, four years later when Percy was 16, he learned that a local paper mill had decided to install electricity, which was still a very new kind of concept at the time. So for context, Thomas Edison is still alive at this time and working on electricity distribution and had patented a system for using electricity as a utility in the 1880s. But Percy was in this very small town so the infrastructure to have electricity power buildings was really just being put into place in many of these small cities and small towns. Arpita: 16:16 Hmm. Aarati: 16:17 But when he heard about this, he became really curious about it. He was like fascinated with the idea of electricity. And so he started learning as much as he could about it by reading about it. And then he applied to help install the system himself at the local mill so that he could get hands on experience. And despite not even having completed grade school education, and of course he had no formal training as an electrical engineer, he was still one of three people chosen to help install the system. Arpita: 16:49 When you say install the system, is this circuits and the wiring? Aarati: 16:54 Yes. So, he basically, through a lot of trial and error, helped install the electricity system and came out having gained a lot of first hand knowledge about circuits and electricity. Arpita: 17:09 Sure. And then was there, I guess, a playbook for how this would be done in general? Like did, had this been already being used in other buildings and then what he had to do in this situation Aarati: 17:20 Yeah, Arpita: 17:20 replicate it to some degree? Aarati: 17:22 I think to some degree. Yes, like again, he's like in a very small town So, I I mean people had been working it out but it's still a very new concept like Edison had only patented this like 20 years ago. So it's like the infrastructure now is slowly being built. And so I'm sure there were a lot of problems they were still trying to figure out. So I think to an extent, yes, they kind of knew what they were doing, but, maybe not completely. It wasn't like... Arpita: 17:50 There was a lot of troubleshooting. Aarati: 17:52 Yeah. Yeah, so specifically, Percy would have learned about alternating current or AC, and we still use AC power today to power buildings, houses, and appliances because it can easily travel through transmission lines. We get electric energy from the movement or flow of electrons and in AC current, that flow will periodically change directions as the electrons in the current changes directions. So I read a really great metaphor that helped me understand this because I was like, I don't understand electricity at all. Like, what are we doing? Um, so I turned to Reddit as one does. Yeah, and there's a user with the fantastic handle toodlesandpoodles. Arpita: 18:41 That's fantastic. Aarati: 18:42 Yeah, and they said you can imagine AC power like a water wheel that you place in the ocean tide. And so as the tide comes in, the water moves in one direction, and the wheel will turn one way. And as the tide goes out, all the water moves in the opposite direction, and so the wheel turns in the opposite direction. And so it doesn't matter which way the wheel is turning. As long as the water is flowing, the wheel will be turning. And so it's the same thing with AC power. As long as the electrons are moving and flowing the appliance or the building or whatever will have power and will be on and working. Arpita: 19:21 That's so interesting. I really like that metaphor. Aarati: 19:23 Yes, it helps make so much sense. I was like, ah, got it. Okay, so the other good thing about AC power is that we can easily regulate the voltage. So a transmission line may have thousands of volts running through it, but by using a transformer, we can change it to the standard 120 volts that all our normal house outlets use or 240 volts that all our large appliances like dishwashers and washing machines use. So. This is probably kind of like the basics of what Percy learned installing power at the paper mill, and it's going to be important context for the rest of his career. So, on April 15th, 1912, when Percy is 18 years old, the world is stunned by the news that the RMS Titanic... Arpita: 20:09 Titanic! I knew that. Aarati: 20:11 The unsinkable ship, yeah, had hit an iceberg and sank. Arpita: 20:16 You know, this is such a random story, but the only reason I know that is because, God knows what year this was, but April 15th was the day that I got my learner's permit. And I remember getting my learner's permit at the DMV. And the man at the DMV was like, today is a really inauspicious day and let's hope that you don't crash the car. And I was like, what are you talking about? And I was 15. So I was just like, a child. And I was like, what are you talking about? And he's like, this is the day that Titanic sank. So at least like, let's hope you don't crash the car. Aarati: 20:46 Oh my god, Arpita: 20:47 I was shook by this as a young child. And for some, for now, April 15th is burned into my memory as the day Aarati: 20:55 my Arpita: 20:55 sank because of that traumatic memory. So thank you, whatever your at the Aarati: 21:00 you know. April 15th, yeah, 1912. Oh my gosh. Arpita: 21:04 Anyway, carry on. That's the Aarati: 21:05 Yes. Okay. Yeah, so we learn about the Titanic sinking and Percy again becomes really curious about this specifically about their wireless system, their radio wireless system. The Titanic had a state of the art Marconi wireless radio to signal other ships and wireless stations on land, and especially when it was sinking, it was sending out all these SOS signals, um, and then after it sank, there was a lot of inquiry about, like, who responded to the wireless signals, who was nearby, could they have gotten there faster? Things like that. So there was a lot of inquiry around that. So he became really interested and part of the reason he became interested in this is because radio waves are a type of electromagnetic wave. Arpita: 21:52 Right. Aarati: 21:54 The idea here is that, okay, we're going to do a little picturing exercise. So imagine you have a metal bar that has an AC electric current running through it. So if you have that, then the electrons in the metal bar would be changing direction and oscillating back and forth inside the bar, like we mentioned earlier. So just like the ocean tide flowing in and out, these electrons are moving back and forth and they create an electric field. around themselves as they move back and forth. And so the direction of the electric field that they're generating is changing as the electrons are moving. Arpita: 22:36 Okay. Yeah. Aarati: 22:37 When you map this out, when you map out these oscillations and the change in the direction of the electric field, you get a sinusoidal shape that's going up and down at regular intervals. Arpita: 22:49 That makes sense, because the electrons are changing directions, which means that the field is changing directions, which Aarati: 22:54 Yeah, Arpita: 22:55 you kind of get that Aarati: 22:55 Yeah, up and down. Arpita: 22:57 Cartoony wave of something coming out of a radio tower, which it kind of looks like, like a ridge, basically. Aarati: 23:04 Exactly. Yeah. So now, suppose you have a second metal bar that's near the first metal bar, but it's not touching it. It's not part of the circuit and it's not connected to the electric current. But it can still feel the effects of the oscillating electric field that's being generated by the first bar, right? So it's close enough. So when the electrons in the second bar are within an oscillating electric field, they will start to oscillate too. And so effectively what you've done is you've transmitted this oscillating signal through space. And that's basically what a radio signal is. Arpita: 23:48 so even if there isn't, even if that second bar doesn't have its own current, it's able to be influenced, I guess, by the waves that are coming from the first one. Okay. And so then it's passing it to the next, the third bar and so forth and so on in order to get a signal somewhere. Aarati: 24:05 Yeah, exactly. And so like, that's exactly the basis of radio technology where you have like one metal antenna or metal bar that's connected to the AC power signal, and it emits this wave like signal that the second metal bar or antenna. That is far away, but is still within the electric field, is able to receive. Arpita: 24:26 Got it. Aarati: 24:28 So Percy wants to learn more about this. And so he decides to join the U. S. Navy so he can learn more about wireless radio systems. Percy only spent two years at the Navy before he was medically discharged due to a chronic ear disease. Um, but during that time, yeah, that just kind of popped up out of nowhere. I don't know. Arpita: 24:49 Okay. I was like, I would like to know more Aarati: 24:51 apparently. Yeah, but during this time he studied at their radio school and he also taught himself a bunch of other subjects including trigonometry, calculus, chemistry, physics, and metallurgy. Arpita: 25:06 Wait, what does"taught himself" mean? Aarati: 25:08 So he said, quote, I just got hold of a lot of textbooks and taught myself while I was standing watch at night, end quote, that's it.Bruh. I know. Arpita: 25:19 If nothing else, doing this podcast has made me feel incredibly lazy. Aarati: 25:23 Oh, I know. Right. And he's just like, Oh yeah, well. I'm just going to do this while I'm in the Navy at night. Arpita: 25:30 Also, not comparing, but I guess like also reinforcing the fact that we both started this episode being like, I'm so tired. Aarati: 25:37 Yes. Oh my God. I know. We're so lazy. Arpita: 25:41 We're weak. God's weakest soldiers. Aarati: 25:45 Seriously. So Arpita: 25:46 A little Aarati: 25:47 geniuses we're talking about. Um, So after being discharged from the Navy, he and his brother Al both found jobs at the Wireless Specialty Apparatus Company in Boston, which made commercial and military radio equipment. Here, Percy's co workers noticed how incredibly curious Percy was about everything. They said he would often stay late at night, testing that day's production. And they said, quote,"Many's the time the gang would come back in the morning and find Percy still there. He had stayed up all night just to figure out how things worked." End quote. Arpita: 26:23 I wonder if he had some sort of genetic anomaly that allowed him to function with so little sleep because whatever that anomaly is, I have the opposite of that. So Aarati: 26:33 Just. Arpita: 26:34 I require an inordinate amount of sleep. Aarati: 26:37 Yeah. Yeah. I don't know. He's just, he's just this intensely curious guy. I know people like that, and it kind of makes me feel, I don't know, inferior in some ways, but so many scientists that I know are exactly like that, you know, they're just like super curious, um, it doesn't matter what the time of the day is, it doesn't matter, like, what else is going on in the world, they need to figure whatever it is out, they need to, you know, Do their data collection. They need to do their experiment and you know, the world can end. It doesn't matter. They're in lab figuring things out. Arpita: 27:14 Is the person you're referring to your brother? Aarati: 27:16 oh, there's multiple, but he's definitely one. Yes, he's definitely one. Oh my God. Absolutely. He's, he's absolutely one of those people who can work 16 hours a day and be like, yeah, it's just how life is. Are Arpita: 27:32 No, no. Aarati: 27:33 no. Yeah. So, Percy spends most of World War I making wireless equipment and working with the Navy to help troubleshoot their systems whenever there was an issue. So, around this time, Percy met and married a woman named Louise Larson, and similar to your story about Sasha Shulgin, I really couldn't find out anything about Louise or how they met. Like... Arpita: 27:59 That cracked me up. She just like appeared. Aarati: 28:01 Yeah, this is literally the same story with Louise. Literally, all I know is that they got married sometime between 1918 and 1922. Arpita: 28:11 We don't even have a date. We don't even have a date. Aarati: 28:13 don't even have a date. I know that they had three sons, John, James and George. And then, 30 ish years later, in 1956, Louise died. And that's it. That's That's the limit of information that we have about Larson. So Arpita: 28:31 Women should be seen and not heard and also not recorded in history. Aarati: 28:36 absolutely not. It doesn't, it doesn't matter apparently. But I thought it was worth the mention still. Arpita: 28:42 He did have wife. Aarati: 28:43 Did, he did have a wife. Arpita: 28:44 He did. Aarati: 28:45 and. And sons, yes. Arpita: 28:47 sentence. Aarati: 28:48 Yeah, and sons, and then she died. Yep. So, after World War I, Percy's brother Al went to work for a company called Raytheon, and Percy soon followed him there. It was a tiny startup company at the time, and Percy was only the fifth employee. At Raytheon, Percy was working on power tubes, or vacuum tubes. So, until now, we've been talking about alternating current, or AC power. Vacuum tubes are important for direct current, or DC power. So, in DC power, the electrons are not oscillating and changing direction, they are always moving in one direction. And vacuum tubes help achieve that one directional flow of electrons. So if you think about like the water wheel analogy thing, this time it's like putting the water wheel in a river where Arpita: 29:42 It's only going in one Aarati: 29:43 going in one direction. Yeah, so vacuum tubes or power tubes are basically glass tubes that have a cathode or a negatively charged electrode at one end and an anode, the positively charged electrode at the other end and the space in between is a vacuum. So the system doesn't catch on fire and burn up because there's no oxygen inside for that to happen. Arpita: 30:07 Okay. That makes sense. Aarati: 30:08 Yeah, And this is important because we're about to heat up the cathode so hot that electrons start to fall off of it. And these electrons are negatively charged, so they will be attracted to the positively charged anode on the other end of the tube. So because of this, the electrons will only ever flow in one direction, from the negative cathode to the positive anode. Arpita: 30:32 And then that flow of the electrons falling off, going towards the anode is the direct current. And the Aarati: 30:38 middle part Arpita: 30:38 is the vacuum. There's no oxygen there. So then Aarati: 30:40 Yeah, Arpita: 30:41 on their journey, they cannot catch anything on fire. Aarati: 30:44 Create a spark or catch fire. Yeah. And then there's one more component that you can add to a vacuum tube, which is called a grid, which you can use to transform a weak oscillating AC signal and amplify it into a strong one directional DC signal. And this works with radio waves and light waves, so vacuum tubes become a crucial part of radios, TVs, radar, telephones, and even the very earliest computers. And when I was looking up, like, DC signals and vacuum tubes and stuff I got a lot of hits about guitar amps, so I'm guessing they're used in guitar amps to amplify sound as well. Arpita: 31:27 Interesting. Okay. Definitely not my of expertise, but Yeah, interesting. Aarati: 31:32 Mine either. But yeah, it was like, are you looking this up because you're interested in guitar amps? And I'm like, no, not really, but apparently that's the main, one of the main uses right now. So, Percy became an expert at designing these vacuum tubes for all purposes. Some of his power tube inventions helped radios become a common plug in household item which apparently they weren't before so now people could just have radios in their house Arpita: 32:01 I guess that would require their homes to be wired and for there to be place for them to be plugged in. So I guess that does make sense. Aarati: 32:08 Mm hmm He also created a photoelectric tube that was a major step forward in developing the television tube. So just a couple of his inventions while he was at Raytheon Arpita: 32:19 Was the television called a tube before? Because that would make so much sense. That's why it's called YouTube. Aarati: 32:25 Yeah, I think A television tube. A cathode ray tube consisting of a Arpita: 32:31 Oh, a cathode ray TV. Yes. That makes a lot of sense because like old TVs used to be cathode ray and that's why it would be like flashing really quickly. Definitely. Aarati: 32:39 Mm. Yeah, yeah, yeah. Arpita: 32:41 Wow. Okay. Anyway, I feel like there's a light bulb above my head right Aarati: 32:44 Yeah, like ding, figured it out. Yeah. Yeah. And so he's, he's basically helping like create all of these things. So as the company grew, Percy became chief of the power tube division. His colleagues at Raytheon, many of whom were affiliates working at MIT's radiation laboratory, were amazed that despite never having a formal education, Percy was really able to hold his own in scientific discussions. And in fact, that's what Like I mentioned before, that's part of what made him so innovative. Since he had never been taught the rules of how things should work, he didn't know what was and wasn't possible. And so he was just trying stuff and like figuring it out. and trying to make it work the way he wanted using that Yankee mentality that he had developed. And his co worker said that Percy could have built a working tube out of a sardine can. Arpita: 33:43 That's like a very apt way to phrase that. Aarati: 33:46 Yeah. One of his most notable achievements came about when World War II started. Percy was working on cavity magnetrons. which are a high powered vacuum tube that control and amplify microwaves. So microwaves, and we're talking about the waves here now, um, they have a frequency ranging between 300 megahertz and 300 gigahertz, which is shorter than radio waves, but longer than infrared waves. Arpita: 34:16 Yeah. And also. Between radio and visible light. Visible light is a faster, Aarati: 34:24 Yes. So it goes radio waves, microwaves, Infrared waves, and then visible light. Yeah. So, at the time, detecting and amplifying microwaves was primarily used in radar systems, and could be used to detect objects at a distance. So, anything from monitoring ships at sea, or planes in the air, to detecting incoming missiles. Arpita: 34:49 Mm hmm. Aarati: 34:50 And this, of course, became of great importance during World War II, and there was huge demand from the Allied forces for radar technology. But in 1941, magnetrons could only be produced at a rate of one per week, which was really not enough for the war effort. So, Percy helped Raytheon land a huge government contract to help develop radar equipment for the military. And in fact, this project became the U. S. military's second most important project during World War II, just behind the Manhattan Project. Arpita: 35:23 Wow. Aarati: 35:24 Yeah. Arpita: 35:25 I do imagine there is quite a big gap between number one and number two there, but Aarati: 35:29 yes, yes. I mean, that's why we don't hear about Number two. Arpita: 35:33 Number two. Aarati: 35:33 We only ever hear about number one, but I still thought that was quite notable. Arpita: 35:39 Yeah, yeah, yeah, yeah. There is quite a chasm there, but Aarati: 35:42 Yes. So as part of this project, Percy redesigned the magnetrons so that they could be built using less precision engineering. So you didn't need expert engineers to build a magnetron. And his version used more readily accessible materials and used this conveyor belt like system to build one so that they could be mass produced more quickly and get more radar equipment into the field. So soon they went from producing one magnetron per week to producing 2600 magnetrons per day. Arpita: 36:17 What? Aarati: 36:18 Yeah. Yes. Arpita: 36:22 Like, I had no idea what you were gonna say. I thought you were gonna be like, one magretron a week to, you know, like Aarati: 36:28 like, Arpita: 36:28 10 a week or something. Yeah. Aarati: 36:32 Yeah. Arpita: 36:34 And then you said 2000 something and then I was like, Oh, per month. Yeah, Aarati: 36:42 I did read another source that said, like, they were able to produce seven per day or something. Um, so I'm not sure if it was seven per day or one per week but either way, going from seven per day to 2,600 a day is huge. Arpita: 36:58 Exponential for sure. Aarati: 37:00 yeah, So this achievement undoubtedly helped the Allies win the war, and for this work, the Navy awarded him the Distinguished Public Service Award, which is the highest award that they can give a civilian. Arpita: 37:13 Oh, cause he's not actually in the Navy anymore because of his ear thing. Okay. I was like, why Aarati: 37:17 Yeah, yeah. Arpita: 37:18 I thought he was in the Navy. Okay. Continue. Aarati: 37:19 Yeah, yeah, no, he's working for Raytheon. Arpita: 37:21 Yeah. Yeah. Yeah. Aarati: 37:22 So, yeah, ear thing, yeah. Um, yeah, that random ear thing that just came out of nowhere. But while he was working on these cavity magnetrons during the war, he once again got curious about something. He had been noticing for a while that when it got cold in the building that they were working in, his workers would warm their hands up by holding them over the magnetrons. And there's also kind of this legend that one day, Percy was standing next to an active radar set that had a magnetron in it, and he noticed that a Mr. Goodbar chocolate bar that he had in his pocket had melted. And, uh, That's when he started wondering if he could harness the radiation energy coming from the magnetrons to cook food. He had to wait until World War II was over, but after the war was done, Percy started experimenting with this. So he started by placing popcorn kernels in front of the magnetron's waveguide, and they popped, and so it was the world's first microwave popcorn. Arpita: 38:31 Which is really like a key use for a microwave. I would say that's, you know, in, in the top five for sure. Aarati: 38:39 Absolutely. Um, he next placed an egg inside of a tea kettle in front of the magnetron, and when one of his co workers tried to look inside the kettle to see what was happening, the egg exploded all over his face. But it was soft boiled, so point proven. Like, yeah, it did get cooked. Arpita: 39:02 Oh, like a whole egg. Aarati: 39:04 Yeah, like he, Arpita: 39:05 Oh, I was like, why did it explode? I was trying to figure that out. Aarati: 39:07 Yeah. Arpita: 39:07 Like a whole egg, not like an egg that was cracked. Aarati: 39:10 Yeah. No, it was a whole egg. Arpita: 39:11 It. Got it. Got it. Okay. Okay. Okay. Sorry. That took me a second. Okay. I'm, I'm, following now. I was like, why? Okay. Aarati: 39:19 Yeah. So, The question is, what is happening? How is this working? Microwaves today still have a cavity magnetron inside of them. And that's the thing that produces electromagnetic waves. These waves bounce around inside the metal box of the oven where you keep your food, and are absorbed by the molecules of water, sugar, and fat in your food. This excites the molecules and causes them to vibrate, which generates heat, and that cooks your food. So, it's kind of similar to a stove or an oven, where the waves are traveling in through the surface of your food, so the outside of the food gets hotter faster than the inside, and that's why sometimes if you start, heating up a frozen burrito or a frozen dinner or something that's really dense, the outside becomes super hot, but it's still really cold inside. And this also explains why you shouldn't put metal utensils or containers in a microwave because the electromagnetic waves will not be absorbed by metal. It will deflect the waves away from the food and cause the electromagnetic waves to bounce around like crazy, which can damage the inside of the microwave. Arpita: 40:31 Yeah. I, I, I do know this from personal experience. I do remember really young, I covered something Instead of covering it with, like, a plate, I covered it with foil... microwaved the foil. That was crazy. There's sparks flying all over the microwave. But, you know, modern microwaves are actually quite good at, you know, the inside of the microwave was not well. But it really does a good job of keeping the bad contained. Aarati: 40:55 Yes. Yes. Arpita: 40:56 Because I think they know that children are probably prone to something like this. Aarati: 41:00 Probably. Yeah. So, to that point, um, the reason that, like, sparks were being created is because the electromagnetic waves were creating an electric current that is running through the metal, and that's what caused the spark and could have potentially caused a fire or, um, Or even caused the microwave to explode, so I'm really glad that didn't happen in your case. Arpita: 41:25 me too. Aarati: 41:26 And one more interesting thing I learned is that, you know how the door of microwaves are always covered in this kind of like mesh material, so it's not completely a clear window? Yeah, so you can see the food inside. That mesh is specifically designed to prevent microwaves from leaving the inside of the oven, so you don't absorb any microwaves and you don't get cooked. Arpita: 41:47 Yeah, I actually did know that and I think it's so crazy that those holes are very big. Like you think about like a wave, it's like those waves are huge and moving very slowly because they can't escape through that grid, even though the grid, the holes are like quite big, I would Aarati: 42:06 Yeah. I did not know this. And so, like, as soon as I learned this, I went and ran to my microwave and I was like, Whoa, those holes are huge. Like, Arpita: 42:13 they are really? Aarati: 42:14 really? Oh my gosh. But it, yeah. So it doesn't allow microwaves to get out, but it does allow visible light. So you can see what's inside. Arpita: 42:22 Because they're smaller and sorry, higher frequency. Yeah. Aarati: 42:25 Yeah. And this is also why there is a safety switch built into microwaves, so if you pull the door open while it's still running, the microwave will shut off immediately. So none of the radiation waves get out. But microwaves are a hundred percent safe. Like you're not going to radiate your food and then ingest it or something like that. And, you know, there it's perfectly safe to eat microwaved food. As long as you're not in the microwave somehow, you're good. So, yeah. So, Percy and his team at Raytheon started developing a magnetron powered oven for cooking food, and in 1945, they applied for a patent for a, quote,"Method of treating foodstuffs". The first commercial microwaves made by Raytheon, called Radar Ranges, hit the shelves in 1947. It was six feet tall and weighed 750 pounds Arpita: 43:19 Six feet tall?! Aarati: 43:21 Yes. Arpita: 43:22 That's crazy. Aarati: 43:24 Yeah, and it cost$5,000, which I looked up the equivalent today, it is$73,000 today for a microwave. Arpita: 43:34 Okay, so this is like a, like a fancy pants thing. Like only, only super fancy households are getting it. Okay. Aarati: 43:39 I don't even think it was for households. I think it was really more intended for like restaurants or like big commercial kitchens. Cause I can't imagine, I can't imagine a household being able to afford that or want that? The first microwave oven for home use came on the market in 1955 and it was still pretty big. It was about the size of a conventional regular oven today. So it had to be wall mounted. And it was also still very expensive. It cost$1,295, which in today's money is over$15,000. So you had to be like wealthy to get a microwave in your house at the time. But, Percy was really not aware of how monumental what he had created was. It took a really long time for microwaves to become small enough and affordable enough for households to afford them. So, Percy never realized how popular and mainstream it would become. He never envisioned this. He also didn't receive any royalties from it. Raytheon gave him a one time$2 bonus that was typical for when employees patented something. And that's all he ever really got from inventing the microwave. Arpita: 44:56 That's wild. Aarati: 44:57 Yeah, isn't that crazy? Arpita: 44:59 But didn't microwaves eventually catch on in a really crazy way? And that's why we ended up with TV dinners and all of these different things that were microwaved. I feel like I remember reading at some point that it became this great way for housewives to manage their households. Like, everything was futuristic. Like, they had an electric vacuum cleaner. They had, you know, microwaves to like cook all their food. And then everything was a la Jetsons from. Aarati: 45:28 Yes. Arpita: 45:28 Yes. Yes. Aarati: 45:29 Yeah. Well, like you said, like, it did take a long time for microwaves to become mainstream. Countertop microwaves first made their way onto the market. Just three years before Percy died in 1967. So they were still pretty pricey at$495, but it, it was like a brand new technology, so it took a while for people to adopt them. Um, but yeah, it, it did catch on eventually and now we have. A microwave practically in every household. Arpita: 46:01 Oh yeah, it was like very gendered marketing. Um, so there was kind of twofold. So early advertisements for microwaves show well coiffed, well heeled housewives happily pulling burnished roasts from their fancy new ovens of the future. So what started out as this wartime technology, but it eventually became marketed for domestic use. So it assured housewives and working mothers that the appliance would streamline the laborious process of getting dinner on the table. Um, yeah, so it was like, very much like widely marketed to women, but then in the 90s, it became marketed to women also, but in a very different way. There was this very famous cookbook that came out called"Microwave Cooking for One" and it had this connotation that it was like sad, single lady references. So a woman living by herself and she didn't cook. She just microwave things for herself. So it's this idea that there's this like busy feminist woman who is a career person and doesn't have. The capacity to cook herself dinner. So she is her things, which is Aarati: 47:13 And that was like, supposed to entice you to buy a microwave because you're a sad, single, career driven lady. Arpita: 47:21 I don't think it was necessarily the marketing, but it was more of the connotation that it came with. Sorry. I maybe misspoke. So the marketing was really meant to be for housewives, but then the connotation of having a microwave changed in the 90s and it was this idea that, you could feed yourself because it was so fast and the only people who really use microwaves were sad single ladies. Aarati: 47:44 Yeah. That, that makes a lot of sense because I remember, my mom got a lot of um, heat in the 90s when she was warming up dinner for us using a microwave because she had a career and so she couldn't stay at home all day like Arpita: 48:00 Totally. Aarati: 48:01 cooking for our family. So she would just come home, zap something in the microwave, put it on the table because we were hungry as soon as we got home from school, you know. And it, it was kind of frowned upon by people around her because they were just like, you should be cooking fresh food for your family, you know, Arpita: 48:18 The fresh food thing is crazy. Aarati: 48:20 Yeah, it's like... I did look up that actually warming up your food in the microwave does not affect the nutritional value of your food at all. And in some cases might actually be better than doing it in a stove or oven because it goes faster. So there's less time for the nutrients to break down in your food. Arpita: 48:39 Also, it's probably less likely to burn in any kind of way or get crispy bits, even though I do like crispy bits because those are carcinogenic and so you're getting less carcinogens. Aarati: 48:48 Yeah. So a lot of benefits to microwaves. Arpita: 48:51 I, I'm fully supportive. Aarati: 48:53 So Percy continued working for Raytheon, becoming a Senior Vice President and Senior Member of the Board of Directors. Over his career, he received over 100 patents. Raytheon even named one of their facilities that manufactured vacuum tubes, Spencer Labs, after him. And despite having dropped out of school in fifth grade, the University of Massachusetts gave him an honorary Doctor of Science degree. So just a side note here again, in 1960, Percy married again, this time to a woman named Lillian Ottenheimer, who is just as mysterious as Louise. We don't know anything about her. So just. Mentioned. We've mentioned her. Yeah. Um, he retired from Raytheon in 1964. And in 1970, Percy dies at the age of 76. And I couldn't find the cause of his death, but I think it was just Old fashioned old age. Arpita: 49:51 Old fashioned old age. Aarati: 49:54 Yep. Arpita: 49:56 What a crazy way to say that. Aarati: 49:59 Nothing special, nothing exciting. Yeah, just good old Arpita: 50:03 He just kicked Aarati: 50:04 Yep. I'm pretty sure that's it, because like, again, I'm looking, I'm like, scouring the internet for information on his wife and his children, and his cause of death, and his father's cause of death, and it's just like, nope, they just don't know. I'm just like, all right, they just died one day, I guess. Like, um, he was 76 though. So I guess that's a pretty good life. Arpita: 50:27 But didn't he die in 1970? Like that doesn't feel, I guess maybe 76. Okay. I don't know. Aarati: 50:32 Yeah. Arpita: 50:32 I don't know. Aarati: 50:33 Um, and my last note here is that posthumously in 1999, Percy was inducted into the inventor's hall of fame for his patent of the high efficiency magnetron, which is what makes the microwaves. Yeah, in a microwave oven. Arpita: 50:48 Cool. Yeah. We've had quite a, we've had quite a few inventor hall of fames. Aarati: 50:52 Yes, we have. So yeah, that's the story of Percy Spencer the grade school dropout who invented, like, the most miraculous machine ever, the microwave. Arpita: 51:04 Great story. I loved it. that was so fun. Aarati: 51:07 Thank you. Thank you very much. I feel so much more enlightened now about the microwave. Arpita: 51:14 Thanks for listening. If you have a suggestion for a story we should cover or thoughts you want to share about an episode, reach out to us at smarttpodcast. com. You can follow us on Instagram and Twitter at smarttpodcast and listen to us on Spotify, Apple Podcasts, or wherever you get your podcasts. 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