WEBVTT - Do Space Elevators Play Space Muzak? 0:00:00.160 --> 0:00:07.400 Brought to you by Toyota. Let's go places. Welcome to 0:00:07.560 --> 0:00:15.480 Forward Thinking. Hi there everyone, and welcome to Forward Thinking, 0:00:15.560 --> 0:00:18.520 the podcast that looks to the future and says, hey, 0:00:19.040 --> 0:00:22.160 I just met you. This is crazy. Here's my number, 0:00:22.400 --> 0:00:26.960 so call me maybe. I'm Jonathan Strickland. I'm Lauren Vocbaum. 0:00:27.000 --> 0:00:29.240 You went like two lines longer than I would have 0:00:29.280 --> 0:00:32.360 thought that, But who are you? Okay, that's all I 0:00:32.400 --> 0:00:35.080 wanted to know. Now, today we wanted to talk a 0:00:35.120 --> 0:00:40.519 bit about space elevators. We recently talked about the concept 0:00:40.560 --> 0:00:43.880 of torque on Forward Thinking and UH, and torque plays 0:00:43.920 --> 0:00:47.440 a big part in space elevators. In general. A space 0:00:47.440 --> 0:00:51.720 elevator is UH, some way for us to climb into space, 0:00:51.800 --> 0:00:55.320 as opposed to using rockets to thrust us into space. 0:00:56.080 --> 0:00:58.280 That's the general idea. Why why would we want to 0:00:58.280 --> 0:01:03.920 do that? Well, mainly because thrusting ourselves into space with 0:01:04.000 --> 0:01:08.319 the help of rockets is incredibly expensive and also more 0:01:08.360 --> 0:01:11.480 than a little dangerous. Whenever you're trying to ride explosives 0:01:11.480 --> 0:01:15.280 into the atmosphere, there comes an element of danger associated 0:01:15.319 --> 0:01:18.560 with that. And but mainly it's cost And if you 0:01:18.600 --> 0:01:21.160 think about it, if we can get things to space, 0:01:21.240 --> 0:01:24.400 without having to have that huge cost. It'll be easier 0:01:24.400 --> 0:01:26.480 for us to get more stuff into space and then 0:01:26.640 --> 0:01:29.440 build stuff in space. You know, if we could build 0:01:29.760 --> 0:01:33.399 spacecraft or space stations in space as opposed to assemble 0:01:33.440 --> 0:01:35.000 them here on Earth and then find some way of 0:01:35.040 --> 0:01:38.640 getting them out there, that could really speed things up. Right. Yeah, 0:01:38.640 --> 0:01:41.000 they don't have to go through the atmosphere. Yeah, you 0:01:41.000 --> 0:01:43.920 could design a spacecraft that was never meant to go 0:01:43.959 --> 0:01:45.880 through the atmosphere and to be perfectly fine because you 0:01:45.959 --> 0:01:48.200 build it out there in space. And we don't want 0:01:48.200 --> 0:01:51.280 to give the impression that we necessarily think that the 0:01:51.360 --> 0:01:54.120 rocket program was not worth what we spent on it. No, 0:01:54.200 --> 0:01:57.160 I'm giving that impression. No, No, of course it was 0:01:57.400 --> 0:02:00.560 very pro space exploit. Yeah, yeah, pro pro rock. It's rockets. 0:02:00.640 --> 0:02:06.080 But the numbers are pretty grim like throughout the history 0:02:06.120 --> 0:02:09.360 of the rocket program. They say that it averaged about 0:02:09.400 --> 0:02:14.720 ten dollars per pound. That's expensive, more expensive than the 0:02:15.560 --> 0:02:18.400 salmon that I like to buy at my local grocery 0:02:18.400 --> 0:02:21.680 store significantly and more expensive. Well, they're they're looking at 0:02:21.720 --> 0:02:25.400 only only four or five a pound for space elevators, right, 0:02:25.560 --> 0:02:28.240 and stuff into space. Now, let's keep in mind that 0:02:28.280 --> 0:02:31.280 of course hypathetic. And this is after we've built one 0:02:31.280 --> 0:02:34.440 of these magical space elevators, which which we haven't done yet. 0:02:34.560 --> 0:02:37.760 But but we're getting ahead of ourselves. People, Where did 0:02:37.760 --> 0:02:41.320 this idea come from? Yes, I do know. Okay, So 0:02:41.360 --> 0:02:43.200 if you want to, if you want to look at 0:02:43.280 --> 0:02:47.440 the first suggestion of building something to allow us to 0:02:47.600 --> 0:02:51.120 get into space without using rockets, you've got to go 0:02:51.240 --> 0:02:55.680 all the way back to eight And that's when a 0:02:55.720 --> 0:03:00.720 fellow by the name Konstantine silkovski H suggested, we uh 0:03:00.760 --> 0:03:03.440 that it's kind of a thought experiment. It wasn't ever 0:03:03.440 --> 0:03:06.800 meant to be a real experiment. But so what if 0:03:06.840 --> 0:03:10.480 we were to build a tower, an actual physical tower, 0:03:11.080 --> 0:03:15.840 from the Earth's surface all the way up into space, 0:03:16.520 --> 0:03:19.799 and the idea being that if you built it high enough, 0:03:20.240 --> 0:03:22.760 you could climb to the top of that tower, step 0:03:22.760 --> 0:03:25.600 off the edge, and you would just stay there because 0:03:25.600 --> 0:03:27.600 you would you would be in orbit around the Earth, 0:03:27.639 --> 0:03:30.079 as opposed to falling plummeting to the Earth. You would 0:03:30.120 --> 0:03:33.120 be beyond gravity in that sense, or really you'd just 0:03:33.160 --> 0:03:34.760 be falling to the Earth at the same rate as 0:03:34.800 --> 0:03:37.280 the Earth is turning, so you're constantly in free fall. 0:03:37.520 --> 0:03:41.840 Would that be geostationary orbit. Well, the tower would be 0:03:41.880 --> 0:03:44.960 in geostationary orbit because it was directly connected to the ground. 0:03:45.040 --> 0:03:47.680 Like it's it's it's a tower, So uh, it's not 0:03:47.760 --> 0:03:49.600 really geo stationary in the since we think of a 0:03:49.600 --> 0:03:55.160 geostationary satellite, um, and you would I guess be geo stationary. 0:03:55.160 --> 0:03:56.640 I guess it would depend on what if you if 0:03:56.640 --> 0:04:00.520 you jump into the atmosphere into the non atmosphere to space, 0:04:00.800 --> 0:04:03.800 then you would be in synchronous orbit kind of. It 0:04:03.800 --> 0:04:05.280 would depend on It would depend on whether or not 0:04:05.320 --> 0:04:08.440 you were at the equator. You should distinguish between geosyncras 0:04:08.520 --> 0:04:13.080 and geostationary right, Okay, same thing, but either way, it 0:04:13.120 --> 0:04:14.720 doesn't It all depends on whether or not you're at 0:04:14.720 --> 0:04:17.920 the equator. So it's the point is kind of mood. Uh, 0:04:17.960 --> 0:04:22.200 But anyway, Constantine suggests building a tower, as you know, 0:04:22.200 --> 0:04:24.720 it's just a thought experiment. Again. Uh. Then you move 0:04:24.800 --> 0:04:27.160 up to about nineteen sixty and then a fellow named 0:04:27.320 --> 0:04:31.720 Urie arts a ton of boy it's I'm terrible at 0:04:32.200 --> 0:04:37.119 these these Russian names, but he suggests a the first 0:04:37.160 --> 0:04:39.360 what we would think of as a real space elevator. 0:04:39.440 --> 0:04:44.160 This is something that is using tensile strength, a taut 0:04:44.480 --> 0:04:47.400 tether as opposed to a tower. So, in other words, 0:04:47.440 --> 0:04:50.719 instead of building a solid structure that reaches all the 0:04:50.760 --> 0:04:55.240 way up into orbit, which would obviously impossible, Yeah, the 0:04:55.279 --> 0:04:58.080 compression that you would the compressive forces that would act 0:04:58.120 --> 0:04:59.840 upon the base of this tower would be so great 0:04:59.839 --> 0:05:03.039 as nothing, nothing we know of could withstand that that 0:05:03.160 --> 0:05:05.640 amount of pressure. The tallest manmade structure in Dubai right 0:05:05.640 --> 0:05:08.279 now is only it comes in under three thousand feet, 0:05:08.800 --> 0:05:12.440 so fewer than the multiple miles exactly. Yeah. Yeah. So 0:05:12.440 --> 0:05:14.719 so this suggestion would be, well, what if instead of 0:05:14.720 --> 0:05:17.920 building a tower, we had the equivalent of a very 0:05:17.960 --> 0:05:21.080 long rope, and that rope where was attached to something 0:05:21.160 --> 0:05:25.640 out beyond uh the initial orbit of the Earth and 0:05:25.720 --> 0:05:27.719 allow or you know, something that would be an orbit 0:05:27.720 --> 0:05:30.200 around the Earth go beyond that point and tie off 0:05:30.240 --> 0:05:33.640 to another object, and then you have essentially centrifugal force 0:05:33.880 --> 0:05:37.359 keeping that that line taut. You have it anchored on 0:05:37.400 --> 0:05:40.320 the ground on one side, anchored to some object that's 0:05:40.320 --> 0:05:42.760 circling the Earth on the other side, and that's what's 0:05:42.800 --> 0:05:45.160 keeping the rope taut. And then you find some way 0:05:45.200 --> 0:05:47.640 of being able to climb that rope, and that was 0:05:47.720 --> 0:05:52.919 the very basic idea that became the space elevator notion. 0:05:53.279 --> 0:05:56.560 There were a few other people who worked independently, uh 0:05:56.600 --> 0:05:58.919 and also came up with the same idea around the 0:05:58.960 --> 0:06:02.040 same time, but his was the first. And uh, the 0:06:02.080 --> 0:06:06.080 idea started getting some traction in the general public beyond 0:06:06.200 --> 0:06:11.279 just you know, physicists and engineers around nineteen nine, and 0:06:11.320 --> 0:06:15.200 that's when Sir Arthur C. Clark wrote The Fountains of Paradise, 0:06:16.400 --> 0:06:19.480 which was a fictional account of this sort of idea 0:06:19.480 --> 0:06:23.000 of building a space elevator. And once that entered into 0:06:23.120 --> 0:06:27.440 the the the circle of science fiction nerds out there, uh, 0:06:27.520 --> 0:06:30.839 the idea started to kind of filter into the general population. 0:06:30.920 --> 0:06:32.480 I'd still say that there are a lot of people 0:06:32.480 --> 0:06:34.840 who don't know what a space elevator is or have 0:06:34.960 --> 0:06:39.520 never heard of this term. But um, but it's it's 0:06:39.560 --> 0:06:43.760 something that is not completely foreign to everyone. A lot 0:06:43.800 --> 0:06:46.640 of sci fi. Yeah. Yeah, And because it's again for 0:06:46.680 --> 0:06:48.640 the idea, the same ideas that we've talked about before, 0:06:48.640 --> 0:06:52.440 it really helps the with a cutting down the cost 0:06:52.880 --> 0:06:55.039 and well, one of the big problems we have with 0:06:55.080 --> 0:07:00.240 our space exploration programs is that they cost a pretty 0:07:00.240 --> 0:07:02.479 good amount of money. Now. Granted, if you compare that 0:07:02.520 --> 0:07:05.360 amount of money to other programs in the United States, 0:07:05.360 --> 0:07:09.160 for example, it's a tiny, tiny amount, but it's still 0:07:09.240 --> 0:07:13.280 an amount you have to convince politicians to spend for 0:07:13.400 --> 0:07:15.760 us to to be able to fund these programs, and 0:07:15.960 --> 0:07:19.360 that gets tough. It's a you could say that there's 0:07:19.400 --> 0:07:22.480 a large return on investment, right, I mean, any scientific 0:07:22.600 --> 0:07:25.000 endeavor is bound to turn out lots of good benefits 0:07:25.000 --> 0:07:27.040 for the future. But sure, even if it's not just 0:07:27.320 --> 0:07:29.720 the space elevator. You know, all kinds of carbon nanotube 0:07:29.720 --> 0:07:33.160 technology and other fascinating things could be created around this, 0:07:33.280 --> 0:07:36.720 which would also be worth the research dollars. But but 0:07:36.720 --> 0:07:39.560 but convincing a politician of that, you say, hey, we 0:07:39.600 --> 0:07:43.240 could get some ideas from this, and they go, who well, well, 0:07:43.560 --> 0:07:45.560 And and not to put all the how soon in 0:07:45.600 --> 0:07:48.000 the next two months, right, And not not to put 0:07:48.000 --> 0:07:51.200 all the blame on politicians because they are answering their inswering, 0:07:51.760 --> 0:07:54.120 because they're innswering to people, and the people are saying, 0:07:54.160 --> 0:07:56.640 I'm paying taxes, where are you spending my tax money on? 0:07:56.720 --> 0:07:59.600 And the politicians says, I'm spending tax money on this thing. 0:07:59.640 --> 0:08:03.440 That may not ever work, and the taxpayer says, why 0:08:03.440 --> 0:08:05.960 am I paying my taxes? So I don't put all 0:08:05.960 --> 0:08:08.360 the blame on the politicians. I hold them accountable, but 0:08:08.400 --> 0:08:11.960 I don't necessarily blame them because I'm not in that position. 0:08:12.040 --> 0:08:14.640 So I'm not the one aging ten years for every 0:08:14.800 --> 0:08:19.720 actual human year. Um. Some of those people seem really comfortable, though, 0:08:19.760 --> 0:08:23.840 so I do blame them a little bit. Anyway, That's 0:08:23.880 --> 0:08:26.160 that kind of covers the history of it. So let's 0:08:26.160 --> 0:08:28.400 talk about what the actual design of one of these 0:08:28.400 --> 0:08:30.080 things would be. And we kind of talked about a 0:08:30.120 --> 0:08:33.760 little bit about that anchor point. But well, essentially, like 0:08:33.840 --> 0:08:37.080 you said, um, it would rely on centrifugal force, but 0:08:37.160 --> 0:08:42.000 not just centrifugal force, right, So you're saying that they're 0:08:42.080 --> 0:08:45.120 essentially two parts. There is a tether and there is 0:08:45.160 --> 0:08:47.800 a climber. Now, if we talk about the tether first, 0:08:47.960 --> 0:08:53.080 this is imagine a long, very thin ribbon going from 0:08:53.120 --> 0:08:58.960 the surface of the Earth at the equator um miles 0:08:58.960 --> 0:09:03.520 out into space right um or sixty very far out 0:09:03.880 --> 0:09:08.360 past geo geostationary orbit um and it would have to 0:09:08.400 --> 0:09:11.120 have something really heavy at the end of it to 0:09:11.280 --> 0:09:15.679 keep it pulled taut. So some ideas have included things like, well, 0:09:15.760 --> 0:09:19.520 let's lasso an asteroid. I'm going to just stop you 0:09:19.720 --> 0:09:22.640 for one second and say we probably should say massive 0:09:22.880 --> 0:09:27.320 rather than heavy. M there you go. Point excellent, but 0:09:27.360 --> 0:09:31.040 that's but but continue, but thanks for breaking my flow there. Yeah, 0:09:31.040 --> 0:09:33.360 you're welcome. So they're going to be writing to me, 0:09:33.480 --> 0:09:37.880 Joe exactly exactly a very massive object like a massive 0:09:37.920 --> 0:09:41.840 asteroid um, or we could just build something really heavy 0:09:41.840 --> 0:09:47.880 out there or one thing massive massive. One idea I 0:09:47.960 --> 0:09:50.760 like a lot that I've heard is just to use 0:09:50.880 --> 0:09:55.440 all of the massive garbage left behind from building things 0:09:55.480 --> 0:09:58.280 in space and make a big trash ball out of it. 0:09:59.040 --> 0:10:02.760 Um that's very massive. So you coalesced all the all 0:10:02.800 --> 0:10:05.600 the trash into one mask, you make a weight out 0:10:05.600 --> 0:10:08.560 of the garbage. Or or for example, a space station 0:10:08.640 --> 0:10:11.160 could be used something that you know, people could live 0:10:11.160 --> 0:10:13.520 on and grow pretty things in or something well, especially 0:10:13.559 --> 0:10:17.079 if you're using that to you know, deliver materials directly 0:10:17.120 --> 0:10:19.840 to the space station. Or the space station is also 0:10:19.920 --> 0:10:22.000 like a space port if we're looking far off into 0:10:22.000 --> 0:10:24.079 the future where you want to build stuff out there. Okay, 0:10:24.160 --> 0:10:26.680 but so what you have to imagine now is that 0:10:27.000 --> 0:10:29.880 it's not just so the centrifugal force acts on that. 0:10:29.960 --> 0:10:32.360 And you just imagine like if you stand somewhere and 0:10:32.400 --> 0:10:34.320 you hold a string with a ball on the end 0:10:34.320 --> 0:10:36.600 of it and spin around in a circle, the weight 0:10:36.640 --> 0:10:38.480 of the ball will pull the string right if you 0:10:38.520 --> 0:10:41.040 If you spin fast enough you start, the ball will 0:10:41.120 --> 0:10:44.160 lift off the ground. And if you're spinning quite fast enough, 0:10:44.200 --> 0:10:47.320 then it'll it'll be pulled taut and almost horizontal out 0:10:47.440 --> 0:10:50.160 from you. Yeah, and but so there are actually two 0:10:50.200 --> 0:10:54.160 forces acting on the tether. So there's the centrifugal force 0:10:54.360 --> 0:10:57.720 pulling the tether outward, and then there's the gravity, just 0:10:58.040 --> 0:11:01.600 the weight of the tether in the Earth's atmosphere pulling 0:11:01.679 --> 0:11:05.000 down on the tether. And these two forces pulling in 0:11:05.040 --> 0:11:09.160 each direction keep the tether straight so something can climate. 0:11:09.400 --> 0:11:12.800 So the the designs I've seen this very thin ribbon, 0:11:12.840 --> 0:11:16.960 it actually has a tapered um element to it has 0:11:17.000 --> 0:11:18.960 to be thickest in the middle. Right in the middle 0:11:19.000 --> 0:11:21.640 it's thickest, and then it tapers down to the thinnest 0:11:21.679 --> 0:11:24.680 points at either end. And it's very much for that 0:11:24.760 --> 0:11:27.120 reason too, in order for it to be strong enough 0:11:27.160 --> 0:11:30.840 to not only withstand the pull from the centrifugal force, 0:11:30.880 --> 0:11:34.040 but also withstand the massive amount of gravity that's pulling 0:11:34.040 --> 0:11:37.560 down on it as well. Um. It's it's interesting too 0:11:38.120 --> 0:11:43.160 that these designs are looking at this this incredibly thin 0:11:43.400 --> 0:11:46.240 ribbon that has to support a huge amount of weight. 0:11:46.600 --> 0:11:49.520 So that's one of the big challenges, right what kind 0:11:49.520 --> 0:11:52.680 of materials could possibly be stretched that thin? Well we'll 0:11:52.679 --> 0:11:55.800 get into that in a minute. But um, I mean, 0:11:55.920 --> 0:11:58.920 because that's the real question, right that that's the central 0:11:59.080 --> 0:12:02.440 can we do it? Well? Anyway, that's the tether, right, Yeah, 0:12:02.559 --> 0:12:05.319 So that's the tether um And another part of the 0:12:05.360 --> 0:12:08.400 tether is the question about where do you put it? Right? 0:12:08.440 --> 0:12:10.120 I mean you say that it has to be it 0:12:10.160 --> 0:12:12.600 has to be active equator, but can you make a 0:12:12.679 --> 0:12:15.839 base that holds it down at the bottom. One thing 0:12:15.880 --> 0:12:19.240 I've seen is that a lot of people propose making 0:12:19.280 --> 0:12:23.000 a mobile sea base, like one that floats in the 0:12:23.000 --> 0:12:26.439 ocean and can move around. And the reason for that is, um, 0:12:26.480 --> 0:12:29.480 what if something is flying towards the tether and you 0:12:29.520 --> 0:12:35.599 need to move it? Oh you know, um, interesting you 0:12:36.600 --> 0:12:39.280 you would want neither a rocket, nor an airplane, nor 0:12:39.400 --> 0:12:42.000 a very large bird to h to run into this. 0:12:42.679 --> 0:12:45.520 So therefore, it can also it's that can help but 0:12:45.600 --> 0:12:49.560 avoid like weather events, you know, yeah, like something in 0:12:49.559 --> 0:12:51.360 the in the Pacific is what I've heard people talk 0:12:51.400 --> 0:12:54.240 about that. So so anyway, so you have the tether, 0:12:54.360 --> 0:12:56.800 it's anchored at this mobile station at the bottom. It's 0:12:56.840 --> 0:12:59.040 got a big weight out in space. And then you 0:12:59.040 --> 0:13:01.920 have the climber and that's the part that's going to 0:13:01.920 --> 0:13:04.679 be most familiar to us. That's just like the elevator 0:13:04.720 --> 0:13:07.320 climber that we're used to. It's a pod or some 0:13:07.440 --> 0:13:11.520 kind of carrying device but rolls up the tether, some 0:13:11.600 --> 0:13:15.920 sort of container that has a means of gripping onto 0:13:15.960 --> 0:13:19.480 that ribbon and climbing it. Uh. Usually we talk about 0:13:19.480 --> 0:13:22.280 it just being using the force of friction. So it 0:13:22.320 --> 0:13:23.800 has to have something has a lot of torque to 0:13:23.840 --> 0:13:26.920 it that can grip onto that ribbon tightly enough to 0:13:27.000 --> 0:13:29.040 be able to climb up from the surface of the 0:13:29.040 --> 0:13:32.160 Earth all the way up with rollers or Yeah. The 0:13:32.200 --> 0:13:34.560 further up it goes, the less it has to deal 0:13:34.600 --> 0:13:39.240 with gravity. But then the centrical force can actually take 0:13:39.280 --> 0:13:42.760 over ultimately. But while you're trying to get it up 0:13:42.760 --> 0:13:44.440 that high, you have to have something that's gonna grip 0:13:44.440 --> 0:13:48.760 on quite tightly and uh so it's interesting also about 0:13:48.800 --> 0:13:50.640 how do you power something like that, how do you 0:13:51.679 --> 0:13:55.640 give energy to this climber so it keeps on going up. 0:13:55.679 --> 0:13:59.000 And by the way, these climbers can be of various sizes. 0:13:59.040 --> 0:14:01.719 There's there's some talk about some of the designs I've 0:14:01.720 --> 0:14:06.120 read talked about climbers that would carry a certain amount 0:14:06.280 --> 0:14:08.960 of like certain number of hundreds of pounds of material 0:14:09.640 --> 0:14:11.640 and you would be able to send up around six 0:14:11.800 --> 0:14:15.800 or so per day, um on every few hours, you'd 0:14:15.800 --> 0:14:18.080 be able to send another one up. Well, now let's clarify, 0:14:18.280 --> 0:14:21.880 that doesn't mean six there and back none six you 0:14:21.920 --> 0:14:25.920 could launch essentially, so you could in this scenario you'd 0:14:25.920 --> 0:14:29.520 have multiple climbers going up the tether at the same time, right, 0:14:29.640 --> 0:14:32.480 or you might do it over the course of six days. 0:14:32.680 --> 0:14:35.200 One per day is being sent up. Because one of 0:14:35.240 --> 0:14:37.960 the issues about a space elevator, you know, one of 0:14:37.960 --> 0:14:40.640 the downsides compared to rockets, is it takes a lot 0:14:40.760 --> 0:14:42.720 longer for you to get out there than it would 0:14:42.760 --> 0:14:45.320 if you were on a rocket. You don't have that 0:14:45.480 --> 0:14:48.880 terrific initial burst you're talking about weeks. Yeah, you're not 0:14:48.920 --> 0:14:51.840 traveling at you know, thirty thousand miles per hour or whatever. 0:14:51.880 --> 0:14:55.240 It's it's climbing at a steady rate, but it could 0:14:55.320 --> 0:14:58.040 take several days or several weeks for it to get 0:14:58.040 --> 0:15:02.200 to where it's going. It's like driving across country. Yeah, 0:15:02.360 --> 0:15:06.560 but more Yes, agreed, And and that means that if 0:15:06.560 --> 0:15:09.240 we're using it to transport people, it would essentially be 0:15:09.320 --> 0:15:13.440 like a hotel room or probably more likely cruise quarters 0:15:13.520 --> 0:15:17.080 on a like a naval vessel, where you would have 0:15:17.080 --> 0:15:21.000 a cramped but serviceable amount of space to yourself that 0:15:21.040 --> 0:15:23.480 would be climate controlled and protected from the elements so 0:15:23.560 --> 0:15:25.960 that you could survive, especially once you start getting out 0:15:26.040 --> 0:15:29.240 beyond the breathable atmosphere to have a pressurized cabin and everything. 0:15:29.320 --> 0:15:32.920 I've heard concerns about how these pods, if they carried passengers, 0:15:32.960 --> 0:15:38.440 would be subject to possible radiation and sure the atmosphere, Yeah, 0:15:38.520 --> 0:15:41.560 once you get beyond the Earth's protective atmosphere, that would 0:15:41.560 --> 0:15:43.720 definitely be a concern. It's you would have to have 0:15:43.760 --> 0:15:46.160 the right kind of shielding on these pods, even if 0:15:46.200 --> 0:15:50.360 you were just transporting uh, you know, just just raw material. 0:15:50.760 --> 0:15:53.040 Depending on that raw material, if you had created any 0:15:53.120 --> 0:15:57.480 circuit boards or anything. Yeah, they're they're electronics that could 0:15:57.480 --> 0:16:01.200 definitely be affected by by any tight of cosmic radiation. 0:16:01.800 --> 0:16:04.000 So you would definitely want to have shielding on your pods, 0:16:04.000 --> 0:16:08.160 whether they're going to be moving life people or whatever 0:16:08.680 --> 0:16:12.320 or inanimate objects. So now with the radiation, we're getting 0:16:12.320 --> 0:16:15.040 into talking about some of the challenges, but I think 0:16:15.120 --> 0:16:17.480 it's time to get to the big challenge. It's the 0:16:17.680 --> 0:16:20.920 one big thing that is making some people say, will 0:16:20.960 --> 0:16:24.240 never have this, it'll never work. Finding a material that 0:16:24.280 --> 0:16:28.000 has the tensile strength to be able to make one 0:16:28.040 --> 0:16:30.840 of these ribbons, that's the big challenge. It's it's just 0:16:31.160 --> 0:16:34.720 mind boggling how strong this tether would have to be. 0:16:34.840 --> 0:16:38.240 I mean, you've never seen a string that's thousands of 0:16:38.280 --> 0:16:42.160 miles long. Uh, it's just impossible to imagine that it 0:16:42.160 --> 0:16:45.480 could withstand the forces, right yeah, And and it would 0:16:45.520 --> 0:16:50.560 have to be uh, incredibly resilient and without it being 0:16:50.800 --> 0:16:54.080 super super super dense and heavy, because you know, the 0:16:54.080 --> 0:16:55.960 heavier it gets, the stronger it has to be in 0:16:56.040 --> 0:17:00.280 order for it to to withstand the the the eensine 0:17:00.280 --> 0:17:04.680 strength from its ownty you know, so uh yeah, And 0:17:05.000 --> 0:17:06.480 not to mention the fact that you're gonna have stuff 0:17:06.480 --> 0:17:08.840 climbing on it. So you you have to have something 0:17:08.880 --> 0:17:11.640 that's both very strong and not super dense. The most 0:17:11.720 --> 0:17:17.280 promising material that we have happens to be carbon nanotubes. Yeah, 0:17:17.440 --> 0:17:20.040 well but but but right right now, I mean, okay, 0:17:20.040 --> 0:17:23.720 well there's some different research being done classically, carbon nanotubes, 0:17:23.760 --> 0:17:26.200 once you get them into a into a long string, 0:17:26.240 --> 0:17:30.600 have only been about a millimeter long, right, yeah, so yeah, 0:17:30.640 --> 0:17:33.560 that's not quite long enough to get into space. I 0:17:33.680 --> 0:17:35.560 need a lot of those. Well let's stop for a second, 0:17:35.600 --> 0:17:38.320 just quick definition. What is a carbon nanotube? Okay, you 0:17:38.359 --> 0:17:41.199 take a sheet of graphing. This is a sheet of 0:17:41.320 --> 0:17:44.119 carbon atoms that are all bound together. It looks like 0:17:44.200 --> 0:17:47.240 a bunch of a hexagons, right, that are all bound 0:17:47.240 --> 0:17:50.560 on each side with other hexagons. And it's a sheet 0:17:50.600 --> 0:17:53.240 of graphing. And then you roll that sheet of graphing 0:17:53.280 --> 0:17:56.720 into a tight tube and the edges buying together. That's 0:17:56.720 --> 0:17:59.840 a carbon nanotube. And depending on the way you roll 0:18:00.080 --> 0:18:03.440 that sheet of graphene, so that you know, the various 0:18:03.560 --> 0:18:06.439 edges of those hexagons line up, depending on on what 0:18:06.480 --> 0:18:09.440 direction you roll it, the carbon nanotube will have different 0:18:09.680 --> 0:18:13.520 uh features. It'll if you roll it one way, it's 0:18:13.560 --> 0:18:17.640 an incredible semiconductor. If you roll it another way, it's 0:18:17.800 --> 0:18:22.280 as stronger than steel and many more times lighter than steel. 0:18:22.640 --> 0:18:25.399 So it's a it's kind of talked about as a 0:18:25.440 --> 0:18:29.040 miracle material because there's so many different potential applications for it. 0:18:29.040 --> 0:18:31.440 It shows up a lot in these like well if 0:18:31.520 --> 0:18:35.000 we could do this, yeah, right, carbonanotubes a right kind 0:18:35.000 --> 0:18:39.240 of like that's that's where yeah, except it's real stuff. 0:18:39.280 --> 0:18:41.320 It is real stuff. Yeah. Yeah. They were discovered back 0:18:41.320 --> 0:18:45.960 in by Sameo E Jima UM. But but you know, 0:18:46.320 --> 0:18:47.920 research into this kind of stuff goes back to the 0:18:48.000 --> 0:18:52.680 nineteen fifties and uh, some some new research continuing today. 0:18:53.080 --> 0:18:56.919 Rice University back in January of this year started talking 0:18:56.960 --> 0:18:59.879 about this UM this lamp that they had suspended for 0:19:00.080 --> 0:19:04.960 um A a wet spooled carbon nanotube string that could 0:19:05.000 --> 0:19:09.520 be hundreds of meters long, UM being being suspended and 0:19:09.600 --> 0:19:12.959 powered by this carbon nanotube string due to the electromagnetic 0:19:12.960 --> 0:19:15.399 properties and the kind of the fact that's strong and 0:19:15.600 --> 0:19:19.840 strong enough to yeah, and its online. It's incredible. Yeah, 0:19:19.880 --> 0:19:23.160 this is neat stuff. And so that's very promising. The 0:19:23.160 --> 0:19:27.520 the I've seen some recent criticisms that say that even 0:19:27.720 --> 0:19:31.600 at the proposed strongest that we could make a a 0:19:31.600 --> 0:19:34.560 carbon nanotube right now based upon what we know right now, 0:19:34.920 --> 0:19:37.800 it's still would not meet the requirements of what we 0:19:37.840 --> 0:19:41.000 would need if we were to build this tether. That 0:19:41.000 --> 0:19:45.440 that the tensile strength is not quite what we would require, 0:19:45.480 --> 0:19:47.959 and also that carbon nanitubes, while they be very strong 0:19:48.440 --> 0:19:51.640 in one direction, are very weak in other directions, So 0:19:52.040 --> 0:19:56.840 an impact along the side or some other uh compromising 0:19:57.720 --> 0:20:00.720 event could end up having it just read apart. You 0:20:00.720 --> 0:20:03.639 get a snowstorm or a kite or something and right, yeah, 0:20:03.920 --> 0:20:07.640 or some some some naughty person with scissors. What I've 0:20:07.680 --> 0:20:11.520 seen described is like the chemical bonds on zipping sort 0:20:11.560 --> 0:20:15.439 of zipping the word. The analogy I saw would be 0:20:15.520 --> 0:20:17.600 it would be like getting a run in your stockings, 0:20:18.080 --> 0:20:21.959 which I hate when that happens to me. I know 0:20:22.040 --> 0:20:24.240 you do, Yeah, well, I mean don't don't we all 0:20:24.960 --> 0:20:26.600 you also hate it when it happens to me. That's 0:20:26.680 --> 0:20:30.200 very sweet you, um so? But well okay, so, but 0:20:30.440 --> 0:20:33.359 that's one challenge right there is the biggest one. Well 0:20:33.600 --> 0:20:37.679 not we're not even done with carbon nanotubes, um so, okay, No, 0:20:37.800 --> 0:20:42.520 we're not down earlier, isn't it, Joe. Some experts say, like, 0:20:42.640 --> 0:20:45.720 you can't do the carbon, they're not strong enough. Let's 0:20:45.760 --> 0:20:49.399 imagine that they are strong enough. Some experts disagree, right, 0:20:50.119 --> 0:20:54.040 there's there's materials who say that, yeah, it is strong enough, 0:20:54.080 --> 0:20:57.480 and so obviously we don't know enough to arbitrate on 0:20:57.520 --> 0:21:01.320 that um. But Eve, and if they are strong enough, 0:21:01.480 --> 0:21:04.280 do you know how long it takes to make these 0:21:04.320 --> 0:21:07.560 things and how tiny the amounts we can make at 0:21:07.600 --> 0:21:11.919 one time are. Well, it's like the ways that we 0:21:12.000 --> 0:21:15.040 make them earlier. You describe this hypothetical thing where you're 0:21:15.119 --> 0:21:17.040 rolling up graphinge and that sounds like, oh, it's like 0:21:17.080 --> 0:21:19.440 a big thing of wrapping paper you just rolled out 0:21:20.160 --> 0:21:22.639 the way they make these the atomic scale for that 0:21:22.680 --> 0:21:28.080 to work. But yes, for these extremely uh intense reactions 0:21:28.119 --> 0:21:30.439 you do in some controlled chamber in a lab, like 0:21:30.480 --> 0:21:36.480 you you create arcs of hot electricity between two pieces 0:21:36.480 --> 0:21:40.960 of graphine and some chamber or not graphing graphite and 0:21:41.119 --> 0:21:43.720 uh and that causes like these little pieces of soot 0:21:43.800 --> 0:21:46.800 to come off that that have carbon nanotubes in them, 0:21:46.800 --> 0:21:49.199 and you can collect them. I mean it's it's a 0:21:49.240 --> 0:21:52.680 tiny scale operation. Sure, Yeah, and also there's the problem 0:21:52.760 --> 0:21:57.560 where they cause cancer a lot um in it's it's 0:21:57.600 --> 0:22:00.520 it's it's worse than asbestos when they get into year lungs. 0:22:00.600 --> 0:22:03.280 Never breathing carbon nanotubes if you can avoid it, it's 0:22:03.320 --> 0:22:06.159 a it's it's thought that perhaps um a lot of 0:22:06.200 --> 0:22:09.679 the air pollution UM diseases that are caused are caused 0:22:09.720 --> 0:22:17.639 by carbon nanotubes from naturally occurring processes. Right well, I 0:22:17.640 --> 0:22:20.399 would also go ahead and say that that while that's 0:22:20.520 --> 0:22:23.160 a limiting factor right now, one of the wonderful things 0:22:23.280 --> 0:22:26.359 about technology is that if we see that there's the 0:22:26.400 --> 0:22:31.480 potential for a really transformative material out there, it gives 0:22:31.560 --> 0:22:34.480