WEBVTT - Cities in the Sky 0:00:00.160 --> 0:00:07.240 Brought to you by Toyota. Let's go places. Welcome to 0:00:07.400 --> 0:00:14.800 Forward Thinking. Hey there, every one, and welcome to Forward Thinking. 0:00:14.840 --> 0:00:16.960 The podcast it looks at the future, says, come fly 0:00:17.079 --> 0:00:20.680 with me, Let's fly, Let's fly away. I'm Jonathan Strickland, 0:00:20.800 --> 0:00:24.279 and I'm Joe McCormick and Jonathan. No, I don't want 0:00:24.320 --> 0:00:28.440 to fly. I'm perfectly happy here on the ground. Well, 0:00:28.480 --> 0:00:31.200 you're one of the few. We should also mention before 0:00:31.240 --> 0:00:35.000 we jump into this podcast, our beloved co host Lauren 0:00:35.280 --> 0:00:37.920 is under the weather today, so she will not be here. 0:00:38.280 --> 0:00:40.519 Well we will hope she's feeling better soon. Yes, we 0:00:40.560 --> 0:00:43.400 will carry on and uh and and do her proud. 0:00:43.560 --> 0:00:47.839 So we're gonna talk today about this idea of everything 0:00:47.840 --> 0:00:50.599 from what really it's about defying gravity and not in 0:00:50.680 --> 0:00:54.080 the you know, Idina Menzel Wicked kind of way, or 0:00:54.120 --> 0:00:56.600 maybe in the idea when Menzel wicked kind of way. 0:00:56.640 --> 0:00:59.319 That's obviously the musical Wicked. She has this big song 0:00:59.400 --> 0:01:01.720 defying graph. Okay, I'm not cool enough to get that 0:01:01.760 --> 0:01:04.080 refer Okay, well that's okay the people out there who do. 0:01:04.200 --> 0:01:07.000 But if you reference Huey Lewis, I'm I'm right there 0:01:07.040 --> 0:01:08.920 with you. Got you. Well, we're doing it all for 0:01:09.080 --> 0:01:14.560 never mind. We're talking now about everything from hoverboards to 0:01:14.560 --> 0:01:19.120 to flying cities, to to anything in between. Really and 0:01:19.120 --> 0:01:22.480 and our inspiration here largely comes from the world of 0:01:22.520 --> 0:01:26.400 science fiction. Yeah, so, Jonathan, what's your favorite sci fi 0:01:26.480 --> 0:01:30.480 hover thing? You know, I mean it's cliche to say 0:01:30.560 --> 0:01:32.880 the Back to the Future hoverboard, but it's the Back 0:01:32.920 --> 0:01:35.240 to the Future hoverboard. I remember when I say it 0:01:35.319 --> 0:01:36.840 was one of those things where when you saw it 0:01:36.880 --> 0:01:39.319 for the first time. In Back to the Future Too, 0:01:39.840 --> 0:01:42.240 it's into not one it was in the second one. Yes, 0:01:42.720 --> 0:01:45.040 it really well for the you know, of course, they're 0:01:45.080 --> 0:01:48.080 mirroring a scene that happened in the first film, right 0:01:48.120 --> 0:01:50.000 he he goes up to a kid who has a 0:01:50.000 --> 0:01:52.720 wooden scooter and he rips the top of the scooter 0:01:52.800 --> 0:01:55.680 off and turns it into a skateboard and skates around 0:01:55.760 --> 0:01:58.080 while running from bullies, right and then of course the 0:01:58.080 --> 0:02:01.240 bullies get there, come up and via uh manure truck. 0:02:01.640 --> 0:02:04.280 And then in Back the Future Too, it's kind of 0:02:04.400 --> 0:02:08.440 a mirror of that scene, only this time the Yeah, 0:02:08.440 --> 0:02:12.000 it's it's so really not that far in the future 0:02:13.600 --> 0:02:18.480 today anyway. Year. But yeah, so that by then uh, 0:02:18.520 --> 0:02:21.079 and it's I think made by Mattel if I'm not mistaken. 0:02:21.080 --> 0:02:23.600 It actually has like the logo of the company on 0:02:23.639 --> 0:02:28.560 the branding. Yeah, but it's a a floating a hoverboard. 0:02:28.600 --> 0:02:31.160 It has no wheels, it hovers above the ground. Anyone 0:02:31.160 --> 0:02:33.560 has seeing this movie knows immediately what I'm talking about here. 0:02:34.160 --> 0:02:36.799 And um even at the time when the movie was released, 0:02:37.000 --> 0:02:38.560 I don't know if you ever saw any of the 0:02:38.600 --> 0:02:41.240 interviews or anything that came out around the same time 0:02:41.280 --> 0:02:42.840 as this. I mean, there was a long time ago 0:02:42.880 --> 0:02:47.000 for you, not so long for me. Um. The but 0:02:47.080 --> 0:02:51.240 they actually kind of played up this idea that the 0:02:51.280 --> 0:02:54.440 hoverboards were real, that these things had really been made, 0:02:54.720 --> 0:02:58.360 and the only reason they weren't everywhere in in stores 0:02:58.560 --> 0:03:01.800 is because parent teacher routs were up in arms saying 0:03:01.800 --> 0:03:05.079 that it would be too unsafe and kids couldnot use them. 0:03:05.400 --> 0:03:08.680 And so there was this kind of a interesting rumor 0:03:08.800 --> 0:03:10.880 that was being perpetuated. And keep in mind, this is 0:03:11.200 --> 0:03:14.640 really before you know, the internet could allow these rumors 0:03:14.680 --> 0:03:17.600 to spread like wildfire. But there was a pretty widely 0:03:17.720 --> 0:03:21.799 held belief that in fact, those hoverboards were not special effects. 0:03:21.800 --> 0:03:25.000 They weren't being you know, supported by rigs of any kind. 0:03:25.040 --> 0:03:28.000 They were really real, but they totally weren't really real. 0:03:28.200 --> 0:03:30.320 You know. I feel like even if I had heard 0:03:30.360 --> 0:03:32.720 that as a kid, I don't want to toot my 0:03:32.760 --> 0:03:35.080 own horn, but I think I would have thought that 0:03:35.160 --> 0:03:38.960 sounds not true. I mean, look at this thing. It's 0:03:39.040 --> 0:03:42.040 this little flat piece of plastic. How could it float 0:03:42.080 --> 0:03:44.720 like that? But it turns out a lot of people 0:03:44.920 --> 0:03:47.560 still want to go for this idea because I believe 0:03:47.600 --> 0:03:51.440 it was just last week when a video went viral 0:03:52.160 --> 0:03:55.080 on the internet Tony Hawk wasn't It wasn't Yeah Tony. 0:03:55.240 --> 0:03:58.480 A bunch of celebrities there. There were some professional athletes 0:03:58.680 --> 0:04:01.840 and uh some I think Christopher Lloyd was in it 0:04:01.960 --> 0:04:07.160 from UM and it had a hoverboard. It was h 0:04:07.360 --> 0:04:10.480 u v R. However, it's like promoting this as if 0:04:10.480 --> 0:04:13.720 it were a technology that's coming out this year. Get 0:04:13.720 --> 0:04:16.640 your hoverboard, and and they were filming people using it 0:04:16.720 --> 0:04:19.680 and talking about how cool it was, and all these 0:04:19.720 --> 0:04:23.120 people on the internet were like, whoa, it's finally real. 0:04:24.520 --> 0:04:28.880 Uh sad fact here um not not real. Still there 0:04:28.920 --> 0:04:31.719 there are some good breakdowns on YouTube. I hate to 0:04:31.839 --> 0:04:33.840 spoil the fun, but if you go look them up, 0:04:33.920 --> 0:04:37.960 just look up, you know, hoverboard hoax videos, and you 0:04:37.960 --> 0:04:41.120 can see where people have slowed down frames in particular 0:04:41.160 --> 0:04:43.600 parts of the video where you can see the shadow 0:04:43.680 --> 0:04:48.400 of the crane that's holding these people up moving behind. Yeah. Yeah, 0:04:48.400 --> 0:04:50.640 and that's a that's a giveaway right there. Obviously, it's 0:04:50.640 --> 0:04:53.360 one of those things where if you are a filmmaker 0:04:53.560 --> 0:04:56.520 or making a video or whatever, Uh, it's very easy 0:04:56.600 --> 0:04:59.680 to to overlook something like that that you need to 0:04:59.720 --> 0:05:03.720 have a control over, or to hope that perhaps whatever, 0:05:03.800 --> 0:05:07.040 however you edit the video, that you hide those well 0:05:07.120 --> 0:05:09.640 enough that no one really spoils the fun too early, 0:05:10.400 --> 0:05:12.520 depending upon your point of view, whether it's spoiling fun 0:05:12.640 --> 0:05:16.000 or or just perpetuating a hoax. But well then again, 0:05:16.080 --> 0:05:17.800 figuring it out might have been part of the fund 0:05:17.800 --> 0:05:20.719 they planned. Yeah, and these days, you know, it's people 0:05:20.839 --> 0:05:26.040 have lots of of abilities to really comb over things 0:05:26.480 --> 0:05:30.160 thoroughly when they go up online. And so it's it's 0:05:30.360 --> 0:05:34.680 harder and harder to get a hoax to pass, you know, 0:05:34.760 --> 0:05:37.919 a truly skeptical I it's not impossible, but it is. 0:05:38.040 --> 0:05:41.599 It's challenging. So what's your favorite implementation of this flying 0:05:41.680 --> 0:05:46.040 hovering stuff? Well, I would probably go with the video 0:05:46.080 --> 0:05:49.440 game BioShock Infinite. There's only a few things that fly 0:05:49.560 --> 0:05:52.599 on that like everything everything flies. Okay, so a lot 0:05:52.680 --> 0:05:55.040 of these things seem to be some kind of aircraft 0:05:55.240 --> 0:05:57.839 or whatever. But the city itself, the city where the 0:05:57.839 --> 0:06:02.040 game takes place, is a floating city called Columbia. Called Columbia, 0:06:02.120 --> 0:06:05.040 it's a it's a dystopia, you know, full of evil 0:06:05.120 --> 0:06:08.800 and maybe it's utopia. When it starts, Yeah, it seems 0:06:08.839 --> 0:06:12.520 so nice until it's not until you go into the 0:06:12.560 --> 0:06:16.680 wrong part of town, until everyone in charge of it 0:06:16.760 --> 0:06:19.400 is totally evil. Well there they were evil to start with, 0:06:19.480 --> 0:06:23.040 it's just everyone was going along with it until okay. 0:06:23.200 --> 0:06:27.200 So yeah, you get on this floating city and and well, 0:06:27.760 --> 0:06:29.400 if you know the game, you know the game. But 0:06:29.520 --> 0:06:32.720 if you don't, what happens is there are these like 0:06:32.880 --> 0:06:37.000 glowing discs on the bottoms of the city platforms you 0:06:37.040 --> 0:06:41.760 can see and they basically explain, oh these the city 0:06:41.839 --> 0:06:45.599 is held in the air by quantum levitation, which is 0:06:45.640 --> 0:06:49.360 controlled by a lutess field named after a scientist in 0:06:49.400 --> 0:06:53.400 the game. Uh. And basically this goes along with the 0:06:53.480 --> 0:06:58.479 standard sci fi convention of inventing fake technologies that sound 0:06:58.520 --> 0:07:01.360 realistic because you put the quantum in there. Yeah, it's 0:07:01.440 --> 0:07:04.160 very much like in Star Trek. You can you can 0:07:04.200 --> 0:07:07.719 solve any problem by reversing the polarity. It sounds it 0:07:07.800 --> 0:07:11.080 sounds scientific enough where the average person watching is just 0:07:11.120 --> 0:07:13.360 going to accept that as, oh, this is what they 0:07:13.400 --> 0:07:16.280 do to fix whatever it is. And it's only when 0:07:16.280 --> 0:07:18.640 you start paying attention to you start telling up how 0:07:18.640 --> 0:07:20.840 many times they reverse the polarity for different things that 0:07:20.920 --> 0:07:24.480 you think they don't Really, that's just that's just magical 0:07:24.480 --> 0:07:27.040 speak for saying, flip the switch to make it stop beeping, 0:07:27.120 --> 0:07:29.960 you know. But well, yeah, well it's totally true. I mean, 0:07:30.000 --> 0:07:33.520 if I say I've got a debigulator to shrink you 0:07:33.600 --> 0:07:37.040 down to a pocket size, that sounds ridiculous. But if 0:07:37.080 --> 0:07:41.239 I have a quantum debigulator, it's like, oh okay, it's quantum. 0:07:42.000 --> 0:07:45.000 It uses the power of the atom. So uh, what's 0:07:45.000 --> 0:07:49.320 interesting is that in this implementation, according to some of 0:07:49.360 --> 0:07:54.120 the deeper lore within BioShock infinite, Uh, this quantum levitation 0:07:54.240 --> 0:07:58.400 field allows you to suspend particles in a physical location 0:07:59.160 --> 0:08:01.120 in whatever orient ation you want, which is going to 0:08:01.200 --> 0:08:03.480 be interesting when we talk about a real science a 0:08:03.520 --> 0:08:06.000 little bit later, on. Now, this is this is not 0:08:06.240 --> 0:08:10.880 a real scientific application of the of what we'll be 0:08:10.920 --> 0:08:14.480 talking about later. Believe it or not, BioShock Infinite failed 0:08:14.480 --> 0:08:18.200 to create real anti gravity technology, right. Uh. And so 0:08:18.320 --> 0:08:20.480 we've also got a couple of other ones that we're 0:08:20.480 --> 0:08:24.600 going to mention, Like the Avengers they have their Hellic Harrier. 0:08:24.880 --> 0:08:26.760 As far as I can tell, this is just a 0:08:26.840 --> 0:08:29.640 huge quad rotor kind of thing, yeah, which or I 0:08:29.680 --> 0:08:32.800 don't know how many rotors it has, but it's it's 0:08:32.840 --> 0:08:36.920 not like something crazy magical. It's just like pretend you 0:08:36.960 --> 0:08:39.880 had unlimited energy, right, and that you were able to 0:08:40.000 --> 0:08:43.960 spend these things, these rotors with enough enough speed, and 0:08:44.000 --> 0:08:46.760 you had enough of them to generate the lift necessary 0:08:46.880 --> 0:08:53.559 to lift up this this aircraft carrier, which I would question. Uh. 0:08:53.600 --> 0:08:56.760 The other one I would go with is uh Lando 0:08:56.880 --> 0:09:00.679 Calarisians home, well, wud City star Wars. I don't think 0:09:00.679 --> 0:09:03.400 it was his home. He technically one cloud city I 0:09:03.440 --> 0:09:06.600 think in a gambling I'm sure that is a cloud 0:09:06.640 --> 0:09:08.880 city is where he laid his head at night. That's 0:09:09.160 --> 0:09:12.080 didn't else, gotcha, gotcha. It's not not his not his 0:09:12.160 --> 0:09:13.840 point of origin, but it was where he spent all 0:09:13.840 --> 0:09:16.319 his time. Yeah, I think it's explained just in terms 0:09:16.320 --> 0:09:19.760 of general anti gravity magic. Yeah, I don't think it's 0:09:19.760 --> 0:09:23.800 even explained so much as it just is an interesting visual. However, 0:09:23.960 --> 0:09:25.920 we'll have something more to say about that in this 0:09:25.960 --> 0:09:30.800 episode too. Yeah, okay, So why is it that we 0:09:30.920 --> 0:09:34.360 don't have stuff like this? What makes gravity such? In 0:09:34.480 --> 0:09:37.520 your words in the notes here, I must quote such 0:09:37.559 --> 0:09:40.480 a harsh mistress. Well, as it turns out, gravity is 0:09:40.559 --> 0:09:45.280 a really interesting stuff, and we don't necessarily understand everything 0:09:45.280 --> 0:09:47.240 about it. In fact, you know, one of the things 0:09:47.280 --> 0:09:49.760 that we we one of the bits of information we lack, 0:09:50.400 --> 0:09:53.800 is what is the actual mechanism of gravity? We have 0:09:53.920 --> 0:09:58.000 the placeholder of gravitons, which are the particles, the hypothetical 0:09:58.080 --> 0:10:02.600 particles that made ray work, but we don't you know, 0:10:02.600 --> 0:10:06.640 they're hypothetical. We haven't had any direct observation of them 0:10:06.720 --> 0:10:11.120 or been able to prove their existence in any definitive way. Now, 0:10:11.160 --> 0:10:14.079 mathematically it totally makes sense because and we have to 0:10:14.160 --> 0:10:16.440 have a placeholder there. So that's kind of why we 0:10:16.440 --> 0:10:19.000 we have this thing we call gravitons. I think they're 0:10:19.000 --> 0:10:23.040 in that category where they're consistent with what we know, 0:10:23.360 --> 0:10:27.800 but there's no evidence for them directly right. So, according 0:10:27.840 --> 0:10:31.920 to lots of theories, including the general relativity of theory, 0:10:31.920 --> 0:10:35.640 that a certain Einstein way to go. Einstein came up 0:10:35.640 --> 0:10:39.240 with UH talks about space time and curvature of space 0:10:39.280 --> 0:10:43.720 time and how mass causes a warping of space time. 0:10:44.080 --> 0:10:47.920 So if you have a mass in spacetime, it causes 0:10:47.960 --> 0:10:50.880 space time to warp around it, and that the typical 0:10:51.480 --> 0:10:54.640 example people give is a much simpler one for us 0:10:54.679 --> 0:10:59.160 to understand. So Joe, you and I, let's imagine we're 0:10:59.200 --> 0:11:01.679 holding a rubber sheet, and we're standing far enough apart 0:11:01.679 --> 0:11:04.199 where we're holding that sheet as as tightly as tautly 0:11:04.240 --> 0:11:06.480 as we can. Why are we holding a rubber sheet? 0:11:06.559 --> 0:11:10.640 Because we love science? Joe, Okay, Well, you know it's 0:11:10.640 --> 0:11:13.559 gonna get weirder before he gets less weird. So then 0:11:13.600 --> 0:11:16.880 then Lauren, who has recovered from her being under the weather, 0:11:16.960 --> 0:11:20.560 comes up and rolls a tennis ball across this, uh, 0:11:20.600 --> 0:11:22.640 this rubber sheet which we're holding taught and the rubber 0:11:22.640 --> 0:11:25.240 sheet is taught enough where the tennis ball pretty much 0:11:25.320 --> 0:11:28.079 rolls in straight line from you to me. Okay, okay, 0:11:28.480 --> 0:11:31.319 But then Lauren decides that she's you know, wants to 0:11:31.320 --> 0:11:34.040 get a little impish, and she puts a bowling ball 0:11:34.520 --> 0:11:37.040 in the center of this rubber sheet, which then causes 0:11:37.080 --> 0:11:39.760 the rubber sheet to deform around it. It dips down. 0:11:39.880 --> 0:11:42.000 The weight of the bowling ball is pulling down too 0:11:42.000 --> 0:11:44.319 hard for the rubber sheet to remain taught. Of course, 0:11:44.320 --> 0:11:46.360 you know what else would happen is that the tennis 0:11:46.400 --> 0:11:48.920 ball would roll toward the bowling ball, exactly like if 0:11:48.920 --> 0:11:51.280 you were to try and roll that tennis ball second time, 0:11:51.480 --> 0:11:53.600 instead of going in a straight line, it would immediately 0:11:53.600 --> 0:11:56.640 start to deviate towards the bowling ball, which has deformed 0:11:56.880 --> 0:12:00.120 that that straight plastic sheet. The same thing happen and 0:12:00.200 --> 0:12:03.880 in space time with bodies of large enough mass, I mean, 0:12:04.240 --> 0:12:06.079 any mass is going to warp it a little bit, 0:12:06.120 --> 0:12:09.320 but for you to really significantly warped spacetime, you have 0:12:09.400 --> 0:12:13.200 to have pretty large amounts of mass uh. And so 0:12:13.240 --> 0:12:17.280 that's kind of the the idea behind this whole gravity thing. 0:12:17.320 --> 0:12:20.040 It's also can we can also express it as saying 0:12:20.040 --> 0:12:23.720 that gravity UH is the attraction that two bodies have, 0:12:23.960 --> 0:12:27.640 two bodies of mass have UH, and the amount, like 0:12:27.720 --> 0:12:31.000 the significance of that gravity depends upon two things. The 0:12:31.080 --> 0:12:34.480 size of the mass is involved, and how near or 0:12:34.520 --> 0:12:38.120 far apart they are from one another. Okay, so when 0:12:38.160 --> 0:12:40.360 we're talking about the Earth, the Earth has a pretty 0:12:40.400 --> 0:12:44.520 good hold on us. We're kind of stuck um without 0:12:44.600 --> 0:12:47.760 you know, using some pretty extraordinary means to get our 0:12:47.840 --> 0:12:50.120 feet off the ground for more than a couple of 0:12:50.440 --> 0:12:52.360 you know, more than a second or two, depending upon 0:12:52.400 --> 0:12:55.240 how you're how you're managing to do this trampoline or not. 0:12:55.760 --> 0:12:59.240 So uh, you know, we have to find ways to 0:12:59.400 --> 0:13:03.480 counteract that force of gravity, that that downward accelerating force 0:13:03.559 --> 0:13:08.280 that's constantly pulling upon us. And uh. And so it's 0:13:08.320 --> 0:13:10.640 it's tricky because to do that means that you have 0:13:10.679 --> 0:13:13.240 to expend energy or you have to find some other 0:13:13.320 --> 0:13:18.120 means of counteracting the force of the succeloring force pulling 0:13:18.160 --> 0:13:21.360 you downward. Of course, it's not like flying or even 0:13:21.360 --> 0:13:23.680 floating is a total mystery to us. I mean, we've 0:13:23.720 --> 0:13:26.600 come up with quite a few ways of flying. I mean, 0:13:26.640 --> 0:13:30.760 there is the balloon lighter than air. Uh, and so 0:13:31.040 --> 0:13:35.079 that works by having a material within the balloon that 0:13:35.280 --> 0:13:39.240 is of a of less density than the atmosphere around it, 0:13:39.320 --> 0:13:42.720 So it floats up right. It's it's it's technically called 0:13:42.800 --> 0:13:45.040 lighter than air, tends to be called that. Yeah, if 0:13:45.040 --> 0:13:47.760 you were to if you were to take a a 0:13:47.880 --> 0:13:51.520 ziploc bag or just a sandwich bag of whatever brand 0:13:51.600 --> 0:13:54.640 you like, and it has that little sealable edge, and 0:13:54.720 --> 0:13:56.720 you fill it with air and you seal it, and 0:13:56.760 --> 0:13:58.600 you put that on a pool, it's gonna float on 0:13:58.600 --> 0:14:00.640 top of the pool because that air is less dense 0:14:00.679 --> 0:14:03.600 than the water around it. Yeah. Of course, what makes 0:14:03.640 --> 0:14:06.000 a boat or something float on top of the water 0:14:06.080 --> 0:14:08.839 is the same principle that allows a balloon to float 0:14:08.840 --> 0:14:12.120 in the air. It's this buoyancy issue. So if you 0:14:12.200 --> 0:14:16.800 get some gas that is less dense than our atmosphere 0:14:16.960 --> 0:14:21.080 is particularly no our atmosphere at the altitudes that which 0:14:21.160 --> 0:14:26.880 we can operate without uh encountering some significant difficulties, then 0:14:27.080 --> 0:14:28.720 you can, if you have enough of it, you can 0:14:28.720 --> 0:14:32.920 have enough lifting force to lift a you know, something 0:14:33.000 --> 0:14:35.520 like whether it's a balloon or a blamp or whatever. 0:14:36.200 --> 0:14:39.720 Hydrogen and helium tend to be used the most. Hydrogen 0:14:39.760 --> 0:14:43.160 was used quite a bit until the Hindenburg disaster. And 0:14:43.280 --> 0:14:45.200 the thing about hydrogen is it has a lot of 0:14:45.200 --> 0:14:47.960 lifting power. I mean, it's that's the first element, right 0:14:48.000 --> 0:14:51.480 so you've got this ability to uh, it's it's gonna 0:14:51.520 --> 0:14:53.640 be the least dense, it's gonna be the lightest just 0:14:53.680 --> 0:14:57.000 by definition. Um. And it has a one point one 0:14:57.120 --> 0:15:00.680 kilogram for every cubic meter of gas lifting power. So 0:15:00.720 --> 0:15:04.120 if you have a cubic meter of of hydrogen, uh, 0:15:04.160 --> 0:15:07.800 then it can lift one point one Yeah, but it 0:15:07.880 --> 0:15:12.720 also has one point one million units of fire. Well, yeah, 0:15:12.760 --> 0:15:15.520 it's flammable. That's the that's the big issue. So after 0:15:15.640 --> 0:15:20.440 the Hindenburg disaster, most lighter than air vehicles now rely 0:15:20.480 --> 0:15:24.040 on helium, which is not flammable. It is not volatile 0:15:24.080 --> 0:15:26.240 at all, but it has uh, it doesn't it's not 0:15:26.280 --> 0:15:29.160 as strong either. Has one point oh two kilograms of 0:15:29.240 --> 0:15:32.840 lifting power per cubic meter of helium is. It also 0:15:32.920 --> 0:15:35.120 still more expensive. I know at the time of the 0:15:35.160 --> 0:15:38.280 Hindenburg that hydrogen was cheaper and easier to get your hands. 0:15:38.280 --> 0:15:43.440 Definitely expensive because if you look at scientific papers, they 0:15:43.480 --> 0:15:47.600 talk a lot about how the getting enough helium to 0:15:47.720 --> 0:15:51.480 do things like super cool your particle accelerators is getting 0:15:51.480 --> 0:15:54.400 harder and harder, particularly as people use it for things 0:15:54.440 --> 0:15:56.680 like balloons and stuff. Not that. Not that if you 0:15:56.760 --> 0:15:59.000 get a not that if you get your kid, you know, 0:15:59.160 --> 0:16:01.520 a balloon for or his or her birthday that you 0:16:01.600 --> 0:16:04.200 have just robbed the large Hadron collider of finding the 0:16:04.240 --> 0:16:07.840 next you know, hypothetical particle. But it is an issue. 0:16:08.120 --> 0:16:10.760 It's not something that's easy to get at. Hydrogen. We could, 0:16:11.000 --> 0:16:13.240 you know, by pouring a little energy into water, we 0:16:13.240 --> 0:16:17.880 can get hydrogen. He can't do that with helium. So yeah, 0:16:18.000 --> 0:16:20.880 I would say the idea of creating something like a 0:16:20.960 --> 0:16:25.800 city like Columbia floating on the basis of helium or hydrogen, 0:16:25.960 --> 0:16:28.240 that doesn't seem all that feasible. You would you would 0:16:28.360 --> 0:16:32.000 need so much because I mean, remember that's that's the 0:16:32.080 --> 0:16:35.920 lifting power of a cubic meter of that gas. So 0:16:36.000 --> 0:16:38.520 you would need so many cubic meters to to be 0:16:38.600 --> 0:16:41.640 able to lift something as heavy as a city. Uh, 0:16:41.680 --> 0:16:46.800 it would be pretty ridiculous. But then, um, we can 0:16:46.840 --> 0:16:50.360 look at maybe something like a heavier than air aircraft 0:16:50.400 --> 0:16:52.600 because we do have plenty of examples of those two. 0:16:52.720 --> 0:16:54.760 All right, Yeah, I've flown in one of those things. 0:16:54.800 --> 0:16:59.280 It has wings instead of balloons. Yeah, that's another Yeah, 0:16:59.320 --> 0:17:03.240 this is all about generating lift, and this is one 0:17:03.240 --> 0:17:08.200 of those things that often gets miscommunicated one of the 0:17:08.200 --> 0:17:10.720 the way that I always heard about lift being generated, 0:17:10.800 --> 0:17:14.639 it turns out is not entirely correct. The thing I 0:17:14.680 --> 0:17:16.600 always heard was that, let's say you've got a wing 0:17:16.680 --> 0:17:19.440 going through the air, and it's angled in such a way, 0:17:19.480 --> 0:17:21.760 or the wing is molded in such a way that 0:17:21.840 --> 0:17:24.160 the air over the top of the wing has further 0:17:24.200 --> 0:17:26.919 to travel than the air going beneath the wing, and 0:17:26.960 --> 0:17:30.199 the differences in pressure are what generate lift. That's a 0:17:30.280 --> 0:17:34.399 very common explanation for lift. Is also not technically correct. Well, 0:17:34.400 --> 0:17:37.680 I would think it would have to create upward uh 0:17:37.880 --> 0:17:41.160 force by throwing air down. That's pretty much it. Yeah, 0:17:41.359 --> 0:17:44.159 it turns out that an object moving through a solid 0:17:44.200 --> 0:17:47.359 object moving through a fluid is going to displace that 0:17:47.440 --> 0:17:51.040 fluid the flow of fluid. Now, when we say fluid flow, 0:17:51.560 --> 0:17:54.359 we don't necessarily mean that the fluid itself is moving. 0:17:54.440 --> 0:17:56.960 It can be perfectly stationary. If the object is moving 0:17:57.000 --> 0:17:59.880 through the fluid, that can end up interrupting the quote 0:18:00.040 --> 0:18:02.600 quote flow of the fluid that actually makes it move around. 0:18:03.000 --> 0:18:05.119 Or you could have a stationary object and move the 0:18:05.119 --> 0:18:07.919 fluid past it and and have the same thing, or 0:18:07.960 --> 0:18:10.760 you could have a combination of the two. So anyway, 0:18:10.760 --> 0:18:12.560 if your wing is designed in such a way so 0:18:12.600 --> 0:18:15.760 that it's deflecting the flow more of the flow of 0:18:15.800 --> 0:18:18.600 air downward than upward, then you're going to get a 0:18:18.640 --> 0:18:24.040 perpendicular to the surface I guess of whatever. I if 0:18:24.040 --> 0:18:25.879 it's a fluid container, would be the surface of that 0:18:25.880 --> 0:18:29.840 fluid container. You'll get a perpendicular force called lift. And 0:18:29.920 --> 0:18:33.439 so as you're going forward with great speed, you're trying 0:18:33.480 --> 0:18:36.960 to just slam tons of air down below the bottom 0:18:37.040 --> 0:18:39.320 body of the plane, right, you have to displace enough 0:18:39.359 --> 0:18:41.679 so that it can counteract the weight. So, yeah, thrust 0:18:41.760 --> 0:18:45.520 is very important, like the speed is very important, both 0:18:45.600 --> 0:18:48.479 for a an airplane or jet. You know, it has 0:18:48.520 --> 0:18:51.160 to go fast enough to to to generate this lift 0:18:51.240 --> 0:18:54.000 in order to uh to fly, or a helicopter in 0:18:54.000 --> 0:18:56.640 which case you're talking about the speed of the rotors turning. 0:18:57.160 --> 0:19:00.200 But either way, you know, or if you are sen 0:19:00.480 --> 0:19:02.800 you tell me that the way a helicopter flies is 0:19:02.840 --> 0:19:06.080 by beating the air into submission. Just I guess, kind 0:19:06.080 --> 0:19:09.640 of true. Uh So, that's that's another example of being 0:19:09.680 --> 0:19:12.719 able to defy gravity in a way, but again not 0:19:12.840 --> 0:19:16.440 necessarily something that would work for the city. Uh So, yeah, 0:19:16.440 --> 0:19:18.680 it works like something the size of an airplane. I mean, 0:19:19.080 --> 0:19:22.240 here's one question they ask, like, why don't they make 0:19:22.280 --> 0:19:26.640 airplane bodies stronger? You know, airplanes can crash and disintegrate 0:19:26.680 --> 0:19:29.639 and have all these problems that kill people on board 0:19:29.680 --> 0:19:32.959 when when there's a malfunction, Why don't they just really 0:19:33.000 --> 0:19:36.720 reinforce them. Well, as you keep adding mass to the airplane, 0:19:36.720 --> 0:19:39.760 you're reducing its ability to fly. Yeah, you actually have 0:19:39.840 --> 0:19:43.040 to you know, again, you have to make lift that 0:19:43.119 --> 0:19:45.840 can counteract that weight, and so you have to make 0:19:45.880 --> 0:19:50.280 the aircraft progressively more powerful in order to do that. 0:19:50.359 --> 0:19:52.400 And that's a real and to use more fuel and 0:19:52.440 --> 0:19:54.120 that That kind of brings us to the next one, 0:19:54.160 --> 0:19:57.320 which is rockets. Very similar in that you know, in rockets, 0:19:57.359 --> 0:20:00.640 you're trying to generate thrust. You're generating us that has 0:20:00.720 --> 0:20:03.960 aimed toward the surface of whatever. You know, with a 0:20:04.080 --> 0:20:06.439 rocket that we're trying to send something into space, it's 0:20:06.480 --> 0:20:10.200 directing it down towards the ground. Uh, you're essentially creating 0:20:10.240 --> 0:20:14.480 something that's throwing out mass um at a rate that 0:20:14.680 --> 0:20:19.199 is a greater than the weight of the or the 0:20:19.240 --> 0:20:22.720 mass of the object that there's that's containing the fuel 0:20:23.119 --> 0:20:26.679 and has the spacecraft on it, so uh, you know, 0:20:26.760 --> 0:20:28.919 you could be using you know, when you think about it, 0:20:28.960 --> 0:20:31.480 with a rocket trying to send a spacecraft up, you 0:20:31.520 --> 0:20:33.520 have to first account for, all right, how heavy is 0:20:33.560 --> 0:20:36.520 the spacecraft? How much fuel are we going to need 0:20:36.560 --> 0:20:39.160 in order to generate the thrust necessary for the spacecraft 0:20:39.160 --> 0:20:42.600 to go up? All right, but that fuel weighs something 0:20:42.760 --> 0:20:45.119 that actually adds mass to this. So now we have 0:20:45.160 --> 0:20:47.240 to figure out how much fuel do we need to 0:20:47.280 --> 0:20:49.280 take care of both the spacecraft and the weight And 0:20:49.320 --> 0:20:52.400 wait a minute, that fuel has to go in something. 0:20:52.760 --> 0:20:55.600 How much how much fuel do we now need to 0:20:55.680 --> 0:20:59.439 make the spacecraft and the fuel and the fuel's container 0:21:00.040 --> 0:21:02.920 all go up and launch into orbit. And that's why 0:21:02.960 --> 0:21:06.320 we need such a massive amount of fuel to escape 0:21:06.400 --> 0:21:09.359 Earth and and send stuff up into orbit, and why 0:21:09.520 --> 0:21:12.399 it's so important, or at least it's why why so 0:21:12.440 --> 0:21:16.159 many people are interested in finding an alternative means of 0:21:16.200 --> 0:21:18.920 getting stuff from the ground into space, right because it 0:21:19.200 --> 0:21:21.680 would dramatically cut down on cost, It cuts down and 0:21:21.800 --> 0:21:24.879 risk um uh and it you know, you don't end 0:21:24.960 --> 0:21:29.320 up having to uh burn through millions of gallons of 0:21:29.359 --> 0:21:33.240 fuel each time. So it's or if you're talking about 0:21:33.280 --> 0:21:37.760 solid fuel, million tons of fuel. Um, it's you know, 0:21:37.840 --> 0:21:39.919 it's it's definitely one of those things that is a 0:21:40.000 --> 0:21:43.480 driving force. No no pun intended in the space industry. 0:21:44.119 --> 0:21:46.520 But yeah, again, if you wanted to have rockets on 0:21:46.600 --> 0:21:49.119 your city to keep your city afloat, you would need 0:21:49.240 --> 0:21:51.960 lots and lots of fuel, which would of course add 0:21:52.000 --> 0:21:55.200 to the amount of fuel you would need to keep 0:21:55.200 --> 0:22:00.359