WEBVTT - Super Soakers and Rocket Science 0:00:04.400 --> 0:00:07.800 Welcome to tech Stuff, a production from my Heart Radio. 0:00:11.760 --> 0:00:14.160 Hey there, and welcome to tech Stuff. I'm your host, 0:00:14.240 --> 0:00:16.840 Jonathan Strickland. I'm an executive producer with iHeart Radio. And 0:00:16.880 --> 0:00:20.640 how the tech are you? And since it's summertime, when 0:00:20.640 --> 0:00:23.080 the weather is high and you can reach right up 0:00:23.120 --> 0:00:26.080 and touch the sky, I figure I could talk about 0:00:26.079 --> 0:00:31.120 a fun story about invention and innovation. Uh, something that's 0:00:31.160 --> 0:00:35.400 near and dear to my heart because these things came 0:00:35.400 --> 0:00:38.479 out right when I was in high school and I 0:00:38.520 --> 0:00:42.479 thought they were amazing. I want to talk about the 0:00:42.600 --> 0:00:46.440 super Soaker line of water guns, and not just because 0:00:47.120 --> 0:00:49.559 that's a toy that has a special place in my 0:00:49.600 --> 0:00:52.280 heart because I loved these things when I was a kid, 0:00:52.640 --> 0:00:56.880 but also because it comes from one heck of a pedigree, 0:00:57.000 --> 0:01:02.360 because that technology was the brain child of a rocket scientist, 0:01:02.440 --> 0:01:07.240 a NASA engineer. That engineer would be Lonnie Johnson, a 0:01:07.240 --> 0:01:10.680 man who is countless incredible achievements to his name. He's 0:01:10.680 --> 0:01:14.280 got more than a hundred patents to his name. Admittedly, 0:01:15.000 --> 0:01:18.759 the super soccer bit frequently grabs attention first, although when 0:01:18.840 --> 0:01:22.440 you look at his resume, you think, how did this? 0:01:22.560 --> 0:01:24.920 How was this the lead? How was that the headline 0:01:25.720 --> 0:01:29.600 Lonnie Johnson was born in Mobile, Alabama in ninety nine. 0:01:30.080 --> 0:01:32.119 And I want to mention this right off the bat, 0:01:32.319 --> 0:01:35.120 Nie Johnson's black. And I say that because we have 0:01:35.160 --> 0:01:39.399 to take into account that along the way he was 0:01:39.480 --> 0:01:44.200 facing massive challenges in the form of systemic racism. So 0:01:45.360 --> 0:01:49.520 his achievements are incredible, and you on top of that, 0:01:49.600 --> 0:01:52.560 you have to put into uh take into account rather 0:01:53.120 --> 0:01:56.440 this issue of racism. Uh, you know, he he was 0:01:57.400 --> 0:02:02.080 really facing some enormous obs nicles. Well, Lonnie's father was 0:02:02.120 --> 0:02:04.720 a veteran of World War Two and worked as a 0:02:04.760 --> 0:02:08.519 civilian driver at an Air Force base in Mobile, Alabama, 0:02:08.680 --> 0:02:11.200 and his mother worked in a laundry and as a 0:02:11.280 --> 0:02:14.079 nurse's aid. So when he was a kid, Lonnie became 0:02:14.200 --> 0:02:17.920 interested in learning how stuff works. I can identify with that. 0:02:18.360 --> 0:02:21.520 His father, on top of being a driver, was also 0:02:21.720 --> 0:02:24.040 kind of a d I Y kind of fella. It 0:02:24.080 --> 0:02:27.760 was mostly out of necessity, learning how to fix things 0:02:28.040 --> 0:02:31.600 and occasionally you know, doing odd jobs and stuff. And 0:02:31.680 --> 0:02:36.720 he passed down this d I Y you know, philosophy 0:02:36.840 --> 0:02:39.880 to his children, and Lonnie really took that to heart, 0:02:40.120 --> 0:02:44.040 and sometimes his heart would overrule his head, Like the 0:02:44.080 --> 0:02:47.000 time he was thirteen and decided to take an engine 0:02:47.000 --> 0:02:50.480 out of a lawnmower and connected to a go kart 0:02:50.880 --> 0:02:54.040 he had made out of scraps and then went joy 0:02:54.200 --> 0:02:58.320 riding down the highway. Police had to ask him to 0:02:58.360 --> 0:03:01.600 pull over. Probably not the safest activity for a thirteen 0:03:01.680 --> 0:03:05.160 year old to pursue, but it was a demonstration of 0:03:05.320 --> 0:03:10.600 his his love of engineering, and his family told lots 0:03:10.639 --> 0:03:14.320 of stories of Lonnie taking stuff apart to learn how 0:03:14.360 --> 0:03:16.920 it worked, and of course, you know, it was the 0:03:16.919 --> 0:03:19.880 classic story that he wasn't always able to put it 0:03:19.919 --> 0:03:23.480 back together again. So sometimes when Lonnie got his hands 0:03:23.520 --> 0:03:25.560 on something, that was the last time that something was 0:03:25.600 --> 0:03:29.040 gonna work, but he would learn in the process. They 0:03:29.080 --> 0:03:31.119 also told stories about the time he tried to make 0:03:31.160 --> 0:03:35.720 homemade rocket fuel and nearly set his family's house on fire. 0:03:36.800 --> 0:03:39.960 He would go to Williamson High School, and that was 0:03:40.000 --> 0:03:43.240 an all black high school because this was still in 0:03:43.280 --> 0:03:46.720 the days of segregation here in the South. You know, 0:03:46.840 --> 0:03:50.200 you you had class schools that were whites only, in 0:03:50.240 --> 0:03:52.680 schools that were black so only. And so he went 0:03:52.720 --> 0:03:55.640 to an all black high school. In nineteen sixty eight, 0:03:55.760 --> 0:03:59.280 he in his school entered a science fair competition that 0:03:59.360 --> 0:04:02.760 was held at the University of Alabama at Tuscaloosa, and 0:04:02.840 --> 0:04:05.760 his school was the only black school that was in 0:04:05.880 --> 0:04:10.520 attendance at the fair. And he Johnson had created a 0:04:10.840 --> 0:04:14.720 kind of robot. He called it the Lennox, and it 0:04:14.800 --> 0:04:19.120 was an air powered device. Again made out of scrap materials, 0:04:19.160 --> 0:04:22.520 like he had rated junkyards and stuff and grabbed things 0:04:22.560 --> 0:04:26.120 that would be helpful and made this robot and it 0:04:26.160 --> 0:04:29.640 took home first prize. Now, reportedly, many at the university 0:04:29.680 --> 0:04:32.479 were not thrilled that the top prize was going to 0:04:32.640 --> 0:04:36.760 a black student. Johnson earned a scholarship to attend the 0:04:36.800 --> 0:04:41.159 Tuskegee University and there he earned a bachelor's degree in 0:04:41.400 --> 0:04:44.880 mechanical engineering. He got that degree in nineteen seventy three. 0:04:45.240 --> 0:04:49.919 Then he pursued post graduate studies at Tuskegee and he 0:04:49.960 --> 0:04:55.039 earned a master's degree in nuclear engineering in nineteen seventy five. 0:04:55.160 --> 0:04:58.640 So the guy who who created the super soccer has 0:04:58.680 --> 0:05:02.520 a master's in nuclear your engineering. That's a big old 0:05:02.520 --> 0:05:05.120 while Zephoria right, like, you wouldn't expect that when you 0:05:05.160 --> 0:05:07.719 pick up a toy that this was created by a 0:05:07.800 --> 0:05:12.760 nuclear engineer. Now, for a short while after he graduated 0:05:13.080 --> 0:05:17.200 from his master's degree. Lonnie Johnson worked as a research 0:05:17.279 --> 0:05:21.800 engineer at oak Ridge National Laboratory. That was one of 0:05:21.839 --> 0:05:25.320 the facilities that was involved during the Manhattan Project. It 0:05:25.360 --> 0:05:28.640 was established as part of the Manhattan Project. In fact, 0:05:29.120 --> 0:05:31.240 this was when the United States was first developing the 0:05:31.240 --> 0:05:35.480 atomic bomb during World War Two. Of course, that would 0:05:35.480 --> 0:05:38.200 be ancient history by the time Lonnie Johnson had joined 0:05:38.200 --> 0:05:41.240 the team, but oak Ridge continues to pioneer research in 0:05:41.400 --> 0:05:45.320 things like nuclear physics, including nuclear fusion and an attempt 0:05:45.440 --> 0:05:49.520 to build a working nuclear fusion reactor, which if we 0:05:49.560 --> 0:05:53.520 ever managed to do one that actually creates a sustainable 0:05:53.600 --> 0:05:58.760 fusion reaction, uh, that would be transformative for our energy needs, 0:05:59.160 --> 0:06:01.880 but you know, we have to get there first. Well. 0:06:01.960 --> 0:06:05.159 Johnson would then join the Air Force after that and 0:06:05.240 --> 0:06:09.040 he was assigned to head the Space Nuclear Power Safety 0:06:09.080 --> 0:06:13.599 Section at the Air Force Weapons Laboratory. He stayed there 0:06:13.680 --> 0:06:16.760 until nineteen seventy nine, and at that point he joined 0:06:16.920 --> 0:06:22.159 NASA's Jet Propulsion Laboratory and served as a senior systems engineer. 0:06:22.760 --> 0:06:26.680 He began work on the Galileo project, so he was 0:06:26.760 --> 0:06:30.880 he was part of the Galileo project team. Galileo was 0:06:31.000 --> 0:06:34.040 a probe that we sent to study Jupiter and its moons. 0:06:34.600 --> 0:06:40.320 That project would ultimately be monumentally successful from a scientific perspective. Now, 0:06:40.760 --> 0:06:43.880 Johnson worked on this early on in the program. He 0:06:43.920 --> 0:06:47.720 would not be part of that team when the probe 0:06:47.720 --> 0:06:51.320 would ultimately launched later in the nineteen eighties, but he 0:06:51.400 --> 0:06:56.320 did work on it early on. In Night two, Lonnie 0:06:56.360 --> 0:06:58.920 Johnson would actually leave NASA and returned to the Air 0:06:58.960 --> 0:07:04.039 Force and he was now an Advanced Space Systems Requirements 0:07:04.160 --> 0:07:08.440 Officer at the Strategic Air Command Headquarters. He would also 0:07:08.480 --> 0:07:11.480 serve as the chief of the Data Management branch of 0:07:11.560 --> 0:07:16.120 Strategic Air Command Test and Evaluation Squadron at Edwards Air 0:07:16.120 --> 0:07:19.120 Force Base. He was one of the engineers who would 0:07:19.160 --> 0:07:22.280 also work on the development of the Stealth bomber, which 0:07:22.320 --> 0:07:26.239 was a super secret project at the time. Johnson actually 0:07:26.280 --> 0:07:29.040 talked about how he wouldn't even be able to tell 0:07:29.080 --> 0:07:31.400 his wife what he was working on at the time 0:07:31.440 --> 0:07:35.400 because it was classified as top secret. He would pop 0:07:35.400 --> 0:07:39.320 back over to NASA's Jet Propulsion Laboratory in nineteen seven 0:07:39.440 --> 0:07:43.080 to work on the Cassini project. Cassini was a probe 0:07:43.080 --> 0:07:46.280 that we sent to study Saturn, and he was also 0:07:46.360 --> 0:07:49.760 at work on a project that would unexpectedly evolve into 0:07:49.840 --> 0:07:53.360 the super Soaker. Now, that was something that he had 0:07:53.400 --> 0:07:57.440 been kind of working on on and off for several years. 0:07:57.880 --> 0:08:02.120 You see, Lonnie Johnson did not set out to make 0:08:02.400 --> 0:08:06.000 a new kind of water gun, you know, a water 0:08:06.080 --> 0:08:09.640 gun that would leave those little old squirt guns far behind. 0:08:09.680 --> 0:08:13.640 He wasn't trying to create a weapon of mass saturation. 0:08:14.160 --> 0:08:17.600 It was not his dream to grant battlefield superiority to 0:08:17.640 --> 0:08:19.800 the kid who could go out and buy a water 0:08:19.880 --> 0:08:22.880 gun capable of shooting streams of water further than any 0:08:22.960 --> 0:08:25.800 other on the market. Hy Johnson was trying to do 0:08:26.400 --> 0:08:30.160 something else entirely. He was trying to solve a very 0:08:30.240 --> 0:08:34.560 tricky problem. He wanted to create a heat pump that 0:08:34.679 --> 0:08:38.760 used water instead of free on as a refrigerant. And 0:08:38.800 --> 0:08:41.440 he started on this work way back in the early 0:08:41.520 --> 0:08:43.760 nineteen eighties. So he he did this while he was 0:08:43.800 --> 0:08:45.960 at the Air Force working on the Stealth bomber. So 0:08:46.240 --> 0:08:49.240 he couldn't talk about the stealth bomber work, but he 0:08:49.280 --> 0:08:52.120 could talk about his sort of personal project, which was 0:08:52.559 --> 0:08:54.839 trying to suss out if there would be a way 0:08:54.880 --> 0:08:57.839 to make a working heat pump and effective heat pump 0:08:58.520 --> 0:09:03.480 using water. So we're going to talk about heat pumps 0:09:03.520 --> 0:09:07.040 and how they work and why it was important to 0:09:07.080 --> 0:09:10.240 try and find an alternative to free on so that 0:09:10.320 --> 0:09:12.559 we can have an understanding of what it was that 0:09:12.679 --> 0:09:19.000 was fueling his innovation and ultimately would spawn the super soaker. 0:09:19.040 --> 0:09:22.040 But before we get to all of that, let's take 0:09:22.520 --> 0:09:36.439 a quick break. Okay, let's talk about heat pumps. Uh. Now, 0:09:36.679 --> 0:09:39.160 the heat pumps I'm talking about here, they work in 0:09:39.200 --> 0:09:42.079 a way that's similar to an air conditioner. In fact, 0:09:42.480 --> 0:09:46.480 there are several elements in heat pumps that are identical 0:09:46.640 --> 0:09:49.079 to things you would find in an air conditioner, except 0:09:49.800 --> 0:09:53.959 a heat pump can potentially transfer heat inside a building 0:09:54.520 --> 0:09:57.760 or outside of building. Thus it can either heat or 0:09:58.000 --> 0:10:03.880 cool a building use in one system. Air conditioners are 0:10:03.920 --> 0:10:07.400 not like that. They are a one way thing, right. 0:10:07.400 --> 0:10:10.400 They pull heat out of a building and they bring 0:10:10.440 --> 0:10:13.480 cool air in. But that's it. You can't you can't 0:10:13.559 --> 0:10:15.440 heat a building with an air conditioner. You need a 0:10:15.440 --> 0:10:18.840 separate system. You need a furnace. So a heat bump 0:10:19.240 --> 0:10:22.800 can do both and uh, technically, a heat pump can 0:10:22.840 --> 0:10:25.160 also be a one way type of deal. It could 0:10:25.200 --> 0:10:27.760 also be like an air conditioner if or it could 0:10:27.760 --> 0:10:31.319 be like a furnace if you wanted where it could 0:10:31.320 --> 0:10:35.720 not reverse. The reverse is only made possible by using 0:10:35.800 --> 0:10:39.120 a reversing valve um. But that's the thing is that 0:10:39.160 --> 0:10:41.480 a heat pump can do that. You can have a 0:10:41.559 --> 0:10:45.760 reversing valve installed within the system and you change where 0:10:45.800 --> 0:10:48.400 the heat is being pumped. Really, that's all it is. 0:10:48.440 --> 0:10:52.079 It's it's all a heat transfer system. It transfers heat 0:10:52.240 --> 0:10:55.920 from one location to another. When you're heating a building, 0:10:55.960 --> 0:10:58.880 it means you're taking heat from outside and bringing it inside. 0:10:59.200 --> 0:11:01.480 Then when you're cooling a building, you're taking the heat 0:11:01.480 --> 0:11:04.840 from inside and you're putting it outside. That's really all 0:11:04.880 --> 0:11:09.840 there is to it. But how does it do that well? 0:11:10.000 --> 0:11:13.000 I could technically do a full episode about this, but 0:11:13.200 --> 0:11:15.920 I'll try and keep it short. It's also a little 0:11:15.960 --> 0:11:19.280 tricky to talk about when you don't have visual aids, 0:11:19.400 --> 0:11:23.160 but we're gonna do our best. So your typical air 0:11:23.200 --> 0:11:25.480 to air heat pump solution, there are a lot of 0:11:25.520 --> 0:11:27.599 different types of heat pumps. Will talk about air to 0:11:27.640 --> 0:11:30.360 air because one they're the most common, and too they're 0:11:30.400 --> 0:11:33.960 really simple. But your your basic air to air heat 0:11:34.000 --> 0:11:38.120 pump solution consists of a pair of heat exchangers. You 0:11:38.160 --> 0:11:41.559 have one heat exchanger that's outdoors and you have one 0:11:41.640 --> 0:11:45.839 heat exchanger that's indoors. These are connected via pipes and 0:11:46.000 --> 0:11:49.880 a reversing valve that allows the flow to reverse directions, 0:11:49.960 --> 0:11:53.640 and there's a compressor, and there's also some other valves, 0:11:53.679 --> 0:11:57.880 expansion valves that control the flow of refrigerant in the system, 0:11:57.920 --> 0:12:02.520 and bypasses for those expansion valves. That's also important. So 0:12:02.720 --> 0:12:05.520 I'll talk about expansion valve one and two for the 0:12:06.360 --> 0:12:09.640 sake of this description so that you can understand why 0:12:09.679 --> 0:12:13.160 they exist. And really you only need to if you 0:12:13.200 --> 0:12:16.240 do have a reversing heat pump system. If it's just 0:12:16.280 --> 0:12:18.760 going in one direction, you just need an one expansion 0:12:18.800 --> 0:12:20.280 pump and that's it. You don't even have to have 0:12:20.320 --> 0:12:23.440 a bypass. It's only if you want to both heat 0:12:23.520 --> 0:12:25.760 and cool a building with a heat pump that you 0:12:25.760 --> 0:12:29.040 would need two of them. So let's start with the compressor, 0:12:29.080 --> 0:12:33.040 because really that's where the journey begins, and the compressor's 0:12:33.120 --> 0:12:38.199 job is to compress the refrigerant that's flowing through this system. 0:12:38.240 --> 0:12:42.520 Now compressing a fluid in this case, it's it's essentially 0:12:42.559 --> 0:12:46.640 a vapor. It causes not just the pressure to increase, 0:12:47.000 --> 0:12:50.760 but it also causes the temperature of that fluid to increase. 0:12:51.280 --> 0:12:55.080 So what you end up with is a superheated vapor 0:12:55.200 --> 0:12:58.679 under very high pressure, and you allow that to travel 0:12:58.760 --> 0:13:03.000 through the lines from the compressor. And let's say in 0:13:03.040 --> 0:13:06.000 this case, it's the winter and we want to heat 0:13:06.080 --> 0:13:10.000 the inside of our house, so we would have a 0:13:10.080 --> 0:13:13.520 system set so that the hot, high pressure vapor travels 0:13:13.800 --> 0:13:19.920 to the indoor heat exchanger. Now, this is essentially coils 0:13:20.040 --> 0:13:22.240 of tube being made out of a material that conducts 0:13:22.280 --> 0:13:28.240 heat efficiently, like copper, right. So this super high pressure, 0:13:28.360 --> 0:13:33.720 very hot vapor goes through these coils of tubing. Behind 0:13:33.840 --> 0:13:36.960 the coil of tubing, you have a fan. The fan 0:13:37.120 --> 0:13:44.160 blows cooler air across these hot coils, and that carries 0:13:44.320 --> 0:13:47.720 some of that thermal energy, some of that heat away 0:13:47.720 --> 0:13:51.120 from the coils. That's what's providing the heat to the house. 0:13:51.559 --> 0:13:53.800 That's where the warm air is coming out of the vents. 0:13:53.840 --> 0:13:58.160 It's because that air was blown across these very hot coils, 0:13:58.160 --> 0:14:00.600 and some of that heat transferred to the air and 0:14:00.679 --> 0:14:04.480 thus is warming your house. So the cool air starts 0:14:04.520 --> 0:14:08.080 to pull away some of that thermal energy. Well, as 0:14:08.120 --> 0:14:14.040 the thermal energy goes down inside this this fluid, then 0:14:14.040 --> 0:14:17.040 the fluid itself begins to condense. It begins to convert 0:14:17.120 --> 0:14:21.000 from gas to liquid. And it's still hot, it's still 0:14:21.000 --> 0:14:23.600 had a high pressure. It's just not quite as high 0:14:23.640 --> 0:14:25.400 a pressure as it was when it entered into the 0:14:25.400 --> 0:14:27.800 heat exchanger, and it's not quite as hot as it was. 0:14:28.440 --> 0:14:33.880 But this heated liquid will bypass expansion valve number one, 0:14:33.960 --> 0:14:36.480 So it goes around this valve, it doesn't go through it. 0:14:37.160 --> 0:14:39.120 The expansion valve. If you can think of it as 0:14:39.240 --> 0:14:42.200 as pointing in the direction, it's pointing back the way 0:14:42.880 --> 0:14:47.000 this liquid has come. So it bypasses this valve. Then 0:14:47.040 --> 0:14:49.680 it goes through expansion valve number two that's pointed in 0:14:49.760 --> 0:14:55.040 the opposite way. Now, an expansion valve allows this pressurized 0:14:55.200 --> 0:14:59.640 liquid to expand, for its volume to expand. Well, that 0:14:59.720 --> 0:15:03.280 means is that the pressure of the liquid drops suddenly, 0:15:03.560 --> 0:15:07.840 as does its temperature. That that's the relationship here. When 0:15:07.840 --> 0:15:10.600 you've got high pressure, you've got high temperature. When you've 0:15:10.600 --> 0:15:14.320 got low pressure, you've got low temperature. So this expansion 0:15:14.400 --> 0:15:18.040 valve allows for the rapid expansion of this liquid into 0:15:18.600 --> 0:15:21.280 a kind of a mixture of liquid and vapor that 0:15:21.520 --> 0:15:25.400 is much cooler in temperature. This mixture then passes through 0:15:25.440 --> 0:15:29.960 the coils in the outdoor heat exchanger that's just blowing 0:15:30.080 --> 0:15:35.120 ambient air across the coils. Well, the temperature of the 0:15:35.160 --> 0:15:39.520 refrigerant has now dropped so low that even in the wintertime, 0:15:39.640 --> 0:15:43.840 the air outside is typically warmer than the refrigerant is, 0:15:44.760 --> 0:15:47.600 so it can be very cold outside and still be 0:15:47.640 --> 0:15:50.360 warm enough to warm up the refrigerant quite a bit. 0:15:51.240 --> 0:15:54.440 And so a little bit of thermal energy gets transferred 0:15:54.560 --> 0:15:59.680 into this fluid. The refrigerant then brings along some of 0:15:59.720 --> 0:16:02.320 that the more energy, and it gets pumped back through 0:16:02.440 --> 0:16:06.360 the reversing valve to go back into the compressor, and 0:16:06.400 --> 0:16:09.200 then the whole thing starts up again. Right, the compressor 0:16:09.280 --> 0:16:13.760 compresses this mixture of of vapor and liquid that's cooler 0:16:13.840 --> 0:16:17.880 into a high pressure vapor that is very high temperature 0:16:18.560 --> 0:16:21.480 and puts it back through the system again. Now, if 0:16:21.480 --> 0:16:24.840 you wanted to cool your house this this this whole 0:16:24.880 --> 0:16:29.680 system moves in reverse. So the compressor still compresses the refrigerants, 0:16:29.680 --> 0:16:32.160 still makes it very hot, but now it goes to 0:16:32.200 --> 0:16:35.280 the outdoor heat exchanger, which takes away some of that 0:16:35.320 --> 0:16:38.920 thermal energy and allows the superheated high pressure vapor to 0:16:38.960 --> 0:16:43.920 condense into hot, slightly less hot, and slightly less pressurized 0:16:44.000 --> 0:16:48.560 liquid that then bypasses expansion valve two. It goes to 0:16:48.760 --> 0:16:53.080 expansion valve one, expands into the very low pressure, low 0:16:53.120 --> 0:16:57.800 temperature mixture of vapor and liquid, moves through the indoor 0:16:57.800 --> 0:17:01.360 heat exchanger, which is blowing warm air across these coils. 0:17:01.760 --> 0:17:04.400 The coils are very very cold, so then you get 0:17:04.480 --> 0:17:09.320 cool air blowing into your house, and then the fluid 0:17:09.359 --> 0:17:14.399 continues on back to the compressor. Now, the reason I 0:17:14.480 --> 0:17:17.040 give all that is because you know, you have to 0:17:17.119 --> 0:17:23.360 understand those basic pieces. But why was Johnson working on 0:17:23.440 --> 0:17:27.840 an improvement or attempting to create an improved heat bump. Well, 0:17:27.840 --> 0:17:31.359 it's because the typical heat bump was using free on 0:17:31.800 --> 0:17:36.880 as the refrigerant. Now free on is technically called die 0:17:36.960 --> 0:17:41.600 chlora die flora methane, and this stuff has the useful 0:17:41.640 --> 0:17:44.280 trait of having a boiling point that's all the way 0:17:44.320 --> 0:17:48.240 down to minus twenty nine point eight celsius or minus 0:17:48.280 --> 0:17:52.040 twenty one point six four fahrenheit. Now, remember, like water 0:17:52.080 --> 0:17:54.560 has got a boiling point of a hundred degrees celsius 0:17:54.680 --> 0:17:58.800 or two D twelve fahrenheit. That's pretty hot, but free 0:17:58.840 --> 0:18:02.280 on it'll boil off into a gas at negative twenty 0:18:02.359 --> 0:18:05.480 nine point eight celsius. So you see that even in 0:18:05.600 --> 0:18:09.840 cold winters, there's still enough heat in the ambient air 0:18:09.920 --> 0:18:13.359 to boil off the refrigerant in the heat exchanger. Unless 0:18:13.400 --> 0:18:16.320 you're in like a super duper cold environment where you 0:18:16.359 --> 0:18:19.040 would be kind of stuck, the heat pump would not 0:18:19.080 --> 0:18:22.920 be a big help. However, free on has some drawbacks. Now. 0:18:22.920 --> 0:18:27.480 A big drawback is that it contributes to environmental damage. 0:18:27.640 --> 0:18:32.440 It can it is a chemical that, when released into 0:18:32.440 --> 0:18:36.760 the atmosphere, can do massive damage to the ozone layer. Now, 0:18:36.800 --> 0:18:40.840 this was such a concern in the nine nineties that 0:18:40.920 --> 0:18:44.280 countries agreed to ban the manufacturer of free on. First 0:18:44.760 --> 0:18:48.760 developed nations all agreed to stop manufacturing free on in 0:18:49.080 --> 0:18:53.640 the mid nineties, but for developing countries it was considered 0:18:53.680 --> 0:18:56.560 to be kind of I mean, it's it's looked on 0:18:56.600 --> 0:18:59.600 as a complicated situation. Right. You you have a country 0:18:59.640 --> 0:19:03.520 that's on its way toward development telling it, hey, you 0:19:03.560 --> 0:19:06.520 can't benefit from the same stuff that we benefited from 0:19:06.560 --> 0:19:09.800 because it turns out that's harmful. That's a complicated thing. 0:19:09.920 --> 0:19:14.320 So those countries actually had until to stop making free on. 0:19:14.880 --> 0:19:17.879 These days, we still use free on, but only in 0:19:18.080 --> 0:19:21.679 very specific use cases, like as a fire retardant in 0:19:22.160 --> 0:19:27.119 like submarines or aircraft. So Lonnie Johnson wanted to create 0:19:27.359 --> 0:19:30.440 a new kind of heat pump that would just use 0:19:30.720 --> 0:19:33.520 lane old water as a refrigerant instead of free on. 0:19:33.920 --> 0:19:36.159 So there was this growing concern about free on and 0:19:36.320 --> 0:19:41.000 similar chemicals and their environmental impact, but this was before 0:19:41.680 --> 0:19:45.080 countries had decided to ban the stuff, and so really 0:19:45.160 --> 0:19:48.000 Johnson was just trying to think of an alternative that 0:19:48.119 --> 0:19:52.959 would be you know, practical and uh, you know, have 0:19:53.080 --> 0:19:56.320 less of an environmental impact, and water would definitely fit 0:19:56.400 --> 0:19:59.080 the bill if you could make it work. So he's 0:19:59.560 --> 0:20:03.800 kind of thinking this through and creating a system, and 0:20:03.960 --> 0:20:07.840 part of that meant that he machined his own nozzles. 0:20:08.280 --> 0:20:11.439 So he used machining equipment to make nozzles for his 0:20:11.640 --> 0:20:16.359 heat pump design, and one day, while testing out his 0:20:16.440 --> 0:20:19.399 nozzles in his bathroom, he shot a tight stream of 0:20:19.440 --> 0:20:23.760 water clear across the bathroom in a very focused stream, 0:20:23.800 --> 0:20:28.400 and then got into thinking about water guns. Okay, I'm 0:20:28.400 --> 0:20:31.320 gonna talk more about water guns and their design, but 0:20:31.640 --> 0:20:43.040 first let's take another quick break. Okay, we're back. Let's 0:20:43.080 --> 0:20:46.920 talk about your classic water gun. So this is pretty 0:20:46.960 --> 0:20:50.120 super soaker, the little squirt toy versions of water guns, 0:20:50.160 --> 0:20:52.080 the kinds of that you might find in like a 0:20:52.119 --> 0:20:55.440 dollar store or something. Now, your typical water gun has 0:20:55.440 --> 0:20:59.040 a spring loaded trigger, and that trigger activates a lever. 0:20:59.440 --> 0:21:03.320 That lever in turn activates a very small pump inside 0:21:03.920 --> 0:21:07.119 the water gun, and the pumps job is to pump 0:21:07.200 --> 0:21:10.600 water from a reservoir and the gun. Often with the 0:21:10.680 --> 0:21:13.520 squirt guns, the entire interior of the gun acts as 0:21:13.520 --> 0:21:16.760 a reservoir and it pumps the water through a plastic 0:21:16.800 --> 0:21:19.280 tube and out a narrow path at the end of 0:21:19.320 --> 0:21:22.040 the gun's barrel, where a nozzle focuses the escaping water 0:21:22.160 --> 0:21:24.680 into a stream. So let's take that step by step 0:21:24.680 --> 0:21:28.600 to understand exactly what's working from a mechanical perspective. So, 0:21:29.280 --> 0:21:32.680 you've got your plastic tube that extends into the water reservoir. 0:21:33.560 --> 0:21:36.520 If you follow that plastic tube from the reservoir up, 0:21:36.560 --> 0:21:38.760 you'll see that leads to a pump. And the pump 0:21:38.840 --> 0:21:41.720 is a very simple thing it's a cylinder and it's 0:21:41.760 --> 0:21:44.520 a piston, and the piston, when you pull the trigger, 0:21:44.520 --> 0:21:47.639 will move into the cylinder. Now, when the piston moves 0:21:47.640 --> 0:21:51.280 into the cylinder, it forces water or air or whatever 0:21:51.760 --> 0:21:54.320 out of the cylinder, right, It can't be in the 0:21:54.359 --> 0:21:58.600 cylinder of the pistons. There. Also, inside the cylinder is 0:21:58.720 --> 0:22:03.320 a spring, So the piston enters the cylinder, it compresses 0:22:03.880 --> 0:22:07.320 the spring, and when you release the trigger, it allows 0:22:07.359 --> 0:22:09.960 the spring to expand to full size. That forces the 0:22:09.960 --> 0:22:13.600 piston back out of the cylinder again. And when that happens, 0:22:14.080 --> 0:22:17.160 there's a vacuum, and nature abhors a vacuum. So water 0:22:17.359 --> 0:22:20.880 and or air flows back into the cylinder because it's 0:22:20.920 --> 0:22:24.920 been left empty by the pistons movement. Right. So when 0:22:24.960 --> 0:22:27.840 you pair this with a couple of one way valves 0:22:27.960 --> 0:22:31.760 in those tubes, you have yourself an effective pump. So 0:22:31.840 --> 0:22:35.280 one of those valves will allow water to move from 0:22:35.320 --> 0:22:38.960 the reservoir into the cylinder. So when you let go 0:22:39.040 --> 0:22:41.760 of the trigger and the piston is moving out of 0:22:41.800 --> 0:22:46.320 the cylinder, the pump sucks water up from the tube, 0:22:46.960 --> 0:22:49.280 but the water cannot flow back in the opposite direction. 0:22:49.280 --> 0:22:52.159 This is also why you sometimes have to prime the 0:22:52.200 --> 0:22:54.439 old water pistols, you have to pull the trigger a 0:22:54.440 --> 0:22:57.600 few times because you actually have to use that that 0:22:57.760 --> 0:23:00.840 piston to suction water up from a reservoir to go 0:23:00.960 --> 0:23:03.960 into the pump uh in order to have it ready 0:23:04.000 --> 0:23:07.480 to push the water out of the gun. Now, the 0:23:07.520 --> 0:23:12.040 other one way valve leads from the pump to the 0:23:12.080 --> 0:23:15.880 nozzle in the guns barrel. So when you pull the trigger, 0:23:16.520 --> 0:23:20.160 it pushes the piston through the cylinder, forces water out 0:23:20.200 --> 0:23:22.680 of the pump, and the only place the water can 0:23:22.720 --> 0:23:26.159 go is through this tube, through that one way valve 0:23:26.320 --> 0:23:28.920 and out through the nozzle because the other one way 0:23:29.000 --> 0:23:32.880 valve blocks the water from going back into the reservoir. Now, 0:23:32.920 --> 0:23:36.160 because there is a one way valve right there heading 0:23:36.240 --> 0:23:39.359 to the barrel of the gun, that means when you 0:23:39.440 --> 0:23:42.520 let go of the trigger and you have the suction 0:23:42.640 --> 0:23:45.880 ng action happening again, when the piston is moving out 0:23:45.880 --> 0:23:49.479 of the cylinder, that one way valve seals shut, so 0:23:49.600 --> 0:23:53.159 air cannot come back in through the gun barrel. The 0:23:53.200 --> 0:23:57.520 only place where the section can pull anything through is 0:23:57.520 --> 0:24:01.400 through the reservoir. Because that one way valve allows water 0:24:01.440 --> 0:24:03.639 to go from the reservoir back into the pump. You 0:24:03.680 --> 0:24:06.679 have to have those one way valves or else if 0:24:06.720 --> 0:24:08.560 you were to lego of the trigger and it could 0:24:08.560 --> 0:24:11.720 just pull air from the barrel, then you wouldn't suction 0:24:11.800 --> 0:24:14.359 air up how the reservoir anymore. You can have a 0:24:14.359 --> 0:24:17.200 full water gun and keep pulling that trigger and nothing 0:24:17.240 --> 0:24:19.600 happens because all it's doing is pushing air in and 0:24:19.640 --> 0:24:21.560 out through the barrel of the gun. You have to 0:24:21.600 --> 0:24:25.920 have that valve there to help seal the system properly. 0:24:26.520 --> 0:24:32.160 Now that's your basic squirt gun. Johnson figured he could 0:24:32.200 --> 0:24:35.720 do a bit better now. His help made nozzle was 0:24:35.760 --> 0:24:39.280 just one part of his new invention, of course, and 0:24:39.440 --> 0:24:41.919 Johnson wouldn't work on this all on his own. He 0:24:42.000 --> 0:24:45.400 would kind of work with another inventor named Bruce Dandrade 0:24:45.920 --> 0:24:48.359 to kind of get a better squirt gun design. And 0:24:48.400 --> 0:24:51.879 a big part of it was something that heat pumps 0:24:51.920 --> 0:24:55.400