1 00:00:09,600 --> 00:00:12,280 Speaker 1: Hey, Daniel, you like the outdoors. You're an outdoorsy kind 2 00:00:12,280 --> 00:00:14,800 Speaker 1: of person. Are you a fan of sailing? Oh? Man, 3 00:00:14,840 --> 00:00:17,919 Speaker 1: I love sailing. There's so much to appreciate, the wind, 4 00:00:18,320 --> 00:00:21,920 Speaker 1: the quiet, But mostly it's because it's about applied physics. 5 00:00:22,160 --> 00:00:23,799 Speaker 1: That's the part you love the most about it is 6 00:00:23,880 --> 00:00:26,279 Speaker 1: the physics of sailing. Yeah. You know, you've got the 7 00:00:26,280 --> 00:00:28,120 Speaker 1: wind coming in one way and the boat is pointing 8 00:00:28,160 --> 00:00:30,840 Speaker 1: another way, and you have the you know, the keel 9 00:00:30,960 --> 00:00:34,120 Speaker 1: underneath and the rudder. It's a it's a big complicated calculation, 10 00:00:34,200 --> 00:00:37,040 Speaker 1: all happening in real time under you. Yeah, and you 11 00:00:37,120 --> 00:00:39,279 Speaker 1: might die or or get strounded out and see if 12 00:00:39,320 --> 00:00:41,839 Speaker 1: you if you mess it up, that's right, that's right. 13 00:00:41,880 --> 00:00:45,479 Speaker 1: So physics can save your life. It's good to understand vectors. 14 00:00:45,560 --> 00:00:47,600 Speaker 1: But no, yeah, I always find it really confusing. You know. 15 00:00:47,680 --> 00:00:49,199 Speaker 1: It's like if you want to go one way, you 16 00:00:49,240 --> 00:00:51,440 Speaker 1: actually have to point the boat the other way. But 17 00:00:51,440 --> 00:00:53,479 Speaker 1: then you have to move the sail in line with 18 00:00:53,600 --> 00:00:55,800 Speaker 1: the wind, and so there's like the Bernoulli effect that 19 00:00:55,840 --> 00:00:57,880 Speaker 1: I just I found it. What we're really confusing? It 20 00:00:57,960 --> 00:01:00,520 Speaker 1: is confusing basically, Um, you know, all you need to 21 00:01:00,560 --> 00:01:02,080 Speaker 1: know is if you want to go one way. Make 22 00:01:02,080 --> 00:01:04,520 Speaker 1: sure you point the boat a different direction, right, That's 23 00:01:04,560 --> 00:01:07,240 Speaker 1: the only way to get there. Never never point to 24 00:01:07,280 --> 00:01:26,880 Speaker 1: where you're going. No, that's classic groupie mistake. Him Orgey, 25 00:01:26,880 --> 00:01:29,800 Speaker 1: I'm a cartoonist and the creator of PhD Comics. Hi, 26 00:01:29,920 --> 00:01:33,119 Speaker 1: I'm Daniel. I'm a particle physicist and the co author 27 00:01:33,160 --> 00:01:36,240 Speaker 1: of our book Together We Have No Idea, A Guide 28 00:01:36,240 --> 00:01:39,080 Speaker 1: to the Unknown Universe. Right now, you're listening to our podcast, 29 00:01:39,160 --> 00:01:42,600 Speaker 1: Daniel and Jorge Explain the Universe, a production of I 30 00:01:42,760 --> 00:01:47,120 Speaker 1: Heart Radio, in which we try to find weird, crazy, wacky, interesting, 31 00:01:47,160 --> 00:01:50,240 Speaker 1: amazing things about the universe that will blow your mind 32 00:01:50,320 --> 00:01:52,160 Speaker 1: and explain them to you in a way that makes 33 00:01:52,160 --> 00:01:55,080 Speaker 1: you understand them and also laugh along the way. That's right. 34 00:01:55,120 --> 00:01:57,400 Speaker 1: We take you to all the corners of the universe 35 00:01:57,440 --> 00:02:02,320 Speaker 1: in rockets, in spaceships, in warp drives potentially, and also 36 00:02:02,400 --> 00:02:06,200 Speaker 1: maybe using sailboats. That's right. We want to navigate your 37 00:02:06,240 --> 00:02:09,160 Speaker 1: brain from here to there and all around, and we're 38 00:02:09,160 --> 00:02:12,320 Speaker 1: willing to do in any sort of mental capsule that's possible. 39 00:02:12,400 --> 00:02:14,080 Speaker 1: And so today on the program, we're going to be 40 00:02:14,080 --> 00:02:17,440 Speaker 1: answering a listener question, who was wondering if there are 41 00:02:17,560 --> 00:02:21,360 Speaker 1: better ways to travel through space. That's right. You guys 42 00:02:21,400 --> 00:02:23,880 Speaker 1: might be familiar with the question of how do we 43 00:02:23,919 --> 00:02:26,399 Speaker 1: get from here to there? Right? And if you want 44 00:02:26,400 --> 00:02:28,880 Speaker 1: to fly from Earth to Mars, or Earth to Jupiter, 45 00:02:29,120 --> 00:02:32,239 Speaker 1: or even do another star, you gotta push yourself there, 46 00:02:32,320 --> 00:02:35,040 Speaker 1: or you gotta get your ship going at a certain speed, 47 00:02:35,080 --> 00:02:38,440 Speaker 1: and that requires energy. And most of the technologies that 48 00:02:38,480 --> 00:02:41,560 Speaker 1: we have currently are basically just like a fire spewing 49 00:02:41,560 --> 00:02:43,799 Speaker 1: out the back, and that requires some sort of fuel. 50 00:02:44,000 --> 00:02:46,240 Speaker 1: That's right, you need fuel, And unfortunately there are no 51 00:02:46,360 --> 00:02:49,200 Speaker 1: gas stations between here and Mars, and so that you 52 00:02:49,240 --> 00:02:50,800 Speaker 1: kind of have to bring it all with you. But 53 00:02:50,840 --> 00:02:53,560 Speaker 1: there might be Tesla supercharger stations for all we know. Right, 54 00:02:53,600 --> 00:02:56,000 Speaker 1: isn't that Elon Musk's plan? How does that company doing 55 00:02:56,080 --> 00:02:59,360 Speaker 1: these days? I haven't really checked my stock portfolio, but 56 00:02:59,800 --> 00:03:02,320 Speaker 1: you know, the guy thinks big. So probably as SpaceX 57 00:03:02,360 --> 00:03:04,720 Speaker 1: goes to Mars, he's gonna stop along the way and leave, 58 00:03:04,760 --> 00:03:07,079 Speaker 1: you know, charging stations. Yeah. So to the end the program, 59 00:03:07,080 --> 00:03:10,200 Speaker 1: we'll be talking about an interesting idea about traveling to 60 00:03:10,240 --> 00:03:18,959 Speaker 1: the stars. We'll be talking about solar sales. How do 61 00:03:19,040 --> 00:03:23,320 Speaker 1: they work? Do you really sale our solar cells on sale. Right, 62 00:03:23,400 --> 00:03:25,280 Speaker 1: how did what does this thing even mean? That'd be 63 00:03:25,360 --> 00:03:28,120 Speaker 1: nice if they're on sale, everyone can get one, that's right. 64 00:03:28,680 --> 00:03:31,160 Speaker 1: That's right, more than just our listeners in Delaware. Remember 65 00:03:31,160 --> 00:03:33,160 Speaker 1: that podcast when we were going to cover the state 66 00:03:33,160 --> 00:03:35,680 Speaker 1: of Delaware with solar cells. Oh? Yeah, do we get 67 00:03:35,680 --> 00:03:40,200 Speaker 1: any feedback from delawareans? Oh? Actually we did. Um. First 68 00:03:40,240 --> 00:03:42,960 Speaker 1: of all, they commented that we need to also include Maryland. 69 00:03:43,480 --> 00:03:45,640 Speaker 1: And they weren't defended at all. Actually, they were just 70 00:03:45,680 --> 00:03:47,760 Speaker 1: glad to have any sort of Delaware shout out. They 71 00:03:47,800 --> 00:03:50,720 Speaker 1: say that they don't often get mentioned. Never happens. I 72 00:03:50,720 --> 00:03:54,840 Speaker 1: guess exactly. So we love you, Delaware. Keep listening. Yeah, 73 00:03:54,880 --> 00:03:57,320 Speaker 1: so it's kind of an interesting idea that you can 74 00:03:57,480 --> 00:04:02,000 Speaker 1: make a sale to sale all the deep blue blackness 75 00:04:02,000 --> 00:04:04,360 Speaker 1: of space. Yeah, it's really kind of an awesome idea. 76 00:04:04,600 --> 00:04:07,120 Speaker 1: I mean, you're we're familiar with the wind, right, and 77 00:04:07,400 --> 00:04:09,720 Speaker 1: the wind is a wonderful way to use a sailboat 78 00:04:09,760 --> 00:04:12,040 Speaker 1: because you don't have to bring any fuel with you. Right, 79 00:04:12,320 --> 00:04:14,080 Speaker 1: you go on a motor boat, you've got to bring 80 00:04:14,080 --> 00:04:16,040 Speaker 1: all that fuel with you. It makes your boat heavier, 81 00:04:16,120 --> 00:04:19,560 Speaker 1: it's loud, it's noisy, is obnoxious. Right, One of the 82 00:04:19,600 --> 00:04:22,360 Speaker 1: things I love about sailing is that it's quiet. Right. 83 00:04:22,480 --> 00:04:23,960 Speaker 1: First of all, you don't have to fuel up because 84 00:04:23,960 --> 00:04:26,360 Speaker 1: your fuel is just the wind. And then when you're sailing, 85 00:04:26,360 --> 00:04:29,719 Speaker 1: there's no obnoxious motor sound to listen to. So the 86 00:04:29,760 --> 00:04:32,720 Speaker 1: idea of traveling from one planet to another through space 87 00:04:33,240 --> 00:04:37,040 Speaker 1: using something similar like being propelled without bringing along your 88 00:04:37,040 --> 00:04:39,440 Speaker 1: own fuel, it's a beautiful idea. Yeah, it's kind of 89 00:04:39,440 --> 00:04:42,480 Speaker 1: cool to think that you can ride something out in space, right, 90 00:04:42,480 --> 00:04:45,719 Speaker 1: Like there's something already going there and you can just 91 00:04:45,760 --> 00:04:47,479 Speaker 1: kind of latch onto it and will push you to 92 00:04:47,520 --> 00:04:49,080 Speaker 1: where you want to go. That's right. And you might 93 00:04:49,120 --> 00:04:52,680 Speaker 1: be tempted to say, what's pushing the sail, Like obviously 94 00:04:52,720 --> 00:04:55,360 Speaker 1: on Earth here it's air, But what's pushing your sail 95 00:04:55,400 --> 00:04:57,520 Speaker 1: out in space? Because there's no air in space and 96 00:04:57,520 --> 00:04:59,960 Speaker 1: you're right, right if we're not sailing in that same way. 97 00:05:00,480 --> 00:05:02,360 Speaker 1: And then you might be tempted to say, what about 98 00:05:02,400 --> 00:05:04,560 Speaker 1: the solar wind? These guys have told us about all 99 00:05:04,560 --> 00:05:07,359 Speaker 1: the particles shooting out from the Sun, Is that the 100 00:05:07,400 --> 00:05:09,880 Speaker 1: solar wind that a solar sale would be riding. But 101 00:05:09,960 --> 00:05:12,479 Speaker 1: that's not even the case. It's not it's not the 102 00:05:12,520 --> 00:05:15,200 Speaker 1: solar wind that a solar sale works off of though 103 00:05:15,200 --> 00:05:18,400 Speaker 1: that would be some sort of poetic you know, beautiful parallel. Wait, 104 00:05:18,440 --> 00:05:20,880 Speaker 1: so it's not the solar wind that you would sail 105 00:05:20,920 --> 00:05:24,160 Speaker 1: on in space. No, it seems tempting, right, you'd like 106 00:05:24,200 --> 00:05:27,679 Speaker 1: to have a solar sail boat using the solar wind 107 00:05:27,920 --> 00:05:31,080 Speaker 1: for this beautiful analogy for our whiskey fueled adventures on 108 00:05:31,120 --> 00:05:33,800 Speaker 1: the high seas here. But it's not actually the solar 109 00:05:33,839 --> 00:05:36,320 Speaker 1: wind that pushes along a solar sail. Oh man. The 110 00:05:36,320 --> 00:05:39,200 Speaker 1: solar wind does it give you a sunburn and chapped 111 00:05:39,200 --> 00:05:43,479 Speaker 1: lips at the same time? That's right, It gives you 112 00:05:43,520 --> 00:05:46,400 Speaker 1: that solar wind touseled hair. Also you have deep fried 113 00:05:46,680 --> 00:05:51,800 Speaker 1: probably exactly not recommended, folks, not recommended. It's like a 114 00:05:51,800 --> 00:05:55,560 Speaker 1: Brazilian blowout. But um, Chris here, if you're listening to 115 00:05:55,600 --> 00:05:57,719 Speaker 1: this podcast on the space station, do not stick your 116 00:05:57,760 --> 00:06:01,080 Speaker 1: head at the window to get a solar wind tewseled look. Yeah, instead, right, 117 00:06:01,160 --> 00:06:02,880 Speaker 1: is because that'd be really cool to hear from you, 118 00:06:03,200 --> 00:06:06,520 Speaker 1: exactly exactly. Yeah, So we'll be talking to me about 119 00:06:06,560 --> 00:06:10,600 Speaker 1: the solar sales, the idea that you can go between 120 00:06:10,640 --> 00:06:14,000 Speaker 1: planets or stars or galaxies using a sale to catch 121 00:06:14,200 --> 00:06:16,800 Speaker 1: something out there in space to take you there. And so, 122 00:06:16,839 --> 00:06:19,239 Speaker 1: as we mentioned, this question came to us from Derek 123 00:06:19,320 --> 00:06:22,400 Speaker 1: from Cleveland, and so here is Derek asking his question. Hey, 124 00:06:22,480 --> 00:06:25,880 Speaker 1: Daniel Jorge, this is Derek from Cleveland, Ohio. My question 125 00:06:25,960 --> 00:06:28,840 Speaker 1: is how does solar sales work if photons are massless? 126 00:06:28,920 --> 00:06:31,440 Speaker 1: How can they impart momentum to a satellite? And how 127 00:06:31,560 --> 00:06:34,760 Speaker 1: is the conservation of momentum upheld? I quickly want to 128 00:06:34,800 --> 00:06:36,680 Speaker 1: say hi to my brother in law, Tim, who I'm 129 00:06:36,720 --> 00:06:39,080 Speaker 1: sure we'll listen and discuss your answer with me later. 130 00:06:39,360 --> 00:06:41,480 Speaker 1: Thanks guys, All right, thank you Derek. That's a pretty 131 00:06:41,520 --> 00:06:44,719 Speaker 1: interesting question. I mean, it's it's sort of um. It 132 00:06:44,760 --> 00:06:46,840 Speaker 1: sounds like he's heard of solar sales and he knows 133 00:06:46,920 --> 00:06:50,680 Speaker 1: they work by catching light, but his question was how 134 00:06:50,680 --> 00:06:53,160 Speaker 1: does that work if photons have no mass? Yeah, so 135 00:06:53,160 --> 00:06:55,560 Speaker 1: many good questions here, right, like how does the solar 136 00:06:55,600 --> 00:06:58,440 Speaker 1: sale work? He seems to understand that it catches light, 137 00:06:58,680 --> 00:07:01,920 Speaker 1: but it doesn't understand like does light half momentum because 138 00:07:01,960 --> 00:07:06,040 Speaker 1: he's probably thinking that momentum is mass times velocity, right, 139 00:07:06,080 --> 00:07:09,160 Speaker 1: which is the case for slow moving massive objects. So 140 00:07:09,200 --> 00:07:11,840 Speaker 1: he's wondering if the mass term is zero, how can 141 00:07:11,880 --> 00:07:13,720 Speaker 1: you have any momentum, Like, how do things with no 142 00:07:13,840 --> 00:07:16,240 Speaker 1: mass have any momentum? And if they have meantum, if 143 00:07:16,240 --> 00:07:18,320 Speaker 1: they don't have momentum, how can they push along a 144 00:07:18,400 --> 00:07:20,680 Speaker 1: solar sale? It's a great question, right, I mean, I 145 00:07:20,720 --> 00:07:23,160 Speaker 1: think it means, like, you know, if light has nothing 146 00:07:23,280 --> 00:07:25,800 Speaker 1: to it in terms of like mass, how can it 147 00:07:25,880 --> 00:07:28,840 Speaker 1: push you? Exactly? That's the question. And so I was 148 00:07:28,920 --> 00:07:31,800 Speaker 1: wondering what people thought about this. So people aware of 149 00:07:31,800 --> 00:07:34,840 Speaker 1: solar sales do they understand photons and momentum and all 150 00:07:34,840 --> 00:07:37,200 Speaker 1: this kind of stuff. And so I went around and 151 00:07:37,240 --> 00:07:40,360 Speaker 1: I asked people, um what they knew about solar sales. 152 00:07:40,640 --> 00:07:42,720 Speaker 1: And before you listen to these answers, think to yourself, 153 00:07:42,800 --> 00:07:45,000 Speaker 1: do you know how a solar sale works? Do you 154 00:07:45,080 --> 00:07:47,880 Speaker 1: understand how light can have momentum if it doesn't have mass. 155 00:07:47,920 --> 00:07:50,080 Speaker 1: Here's what they had to say. I feel like I've 156 00:07:50,120 --> 00:07:51,600 Speaker 1: heard of it, but I'm not sure. I mean, I've 157 00:07:51,640 --> 00:07:54,920 Speaker 1: seen like six once, but I haven't seen I know 158 00:07:54,960 --> 00:07:58,600 Speaker 1: that they're kind of transitioning like testas doing the roof 159 00:07:58,720 --> 00:08:01,360 Speaker 1: tiles and stuff that I was sore, but I don't 160 00:08:02,120 --> 00:08:05,800 Speaker 1: I don't know if I've seen a big pike. I 161 00:08:05,840 --> 00:08:08,720 Speaker 1: guess kind of like sheet of sunlight. Yes, actually I 162 00:08:08,800 --> 00:08:12,120 Speaker 1: have a solar sale is basically a really big sale 163 00:08:12,360 --> 00:08:14,880 Speaker 1: that doesn't get pushed by wind. It gets pushed by 164 00:08:15,120 --> 00:08:18,400 Speaker 1: energy from the sun. So basically energy has a little 165 00:08:18,440 --> 00:08:22,160 Speaker 1: bit of movement in it, and that big movement, a 166 00:08:22,200 --> 00:08:24,640 Speaker 1: little bit of movement can push it because it's not 167 00:08:24,720 --> 00:08:27,440 Speaker 1: too much movement, but it's a lot of energy in 168 00:08:27,880 --> 00:08:30,560 Speaker 1: a big area that that will push it. I'm honestly 169 00:08:30,560 --> 00:08:33,320 Speaker 1: not sure. I couldn't even I couldn't mean guess like 170 00:08:33,520 --> 00:08:36,760 Speaker 1: maybe the stilted price on solar system or something like that. 171 00:08:38,559 --> 00:08:41,280 Speaker 1: All right, I love these answers or I feel like 172 00:08:41,280 --> 00:08:46,199 Speaker 1: they're all correct. Like is it a boat powered by 173 00:08:46,200 --> 00:08:50,000 Speaker 1: solar power? Yes, technically that would be a solar That 174 00:08:50,000 --> 00:08:52,160 Speaker 1: would be like a boat with an electric engine on 175 00:08:52,200 --> 00:08:56,040 Speaker 1: it that's powered by solar cells. That's pretty cool. Yeah, sure, yeah, 176 00:08:56,080 --> 00:08:59,319 Speaker 1: that's like a solar boat for sure. Or like a discount, 177 00:08:59,480 --> 00:09:02,040 Speaker 1: I don't think is it? Is it like a discount 178 00:09:02,040 --> 00:09:04,880 Speaker 1: on solar panel? I think like a solar sale. I 179 00:09:04,920 --> 00:09:06,720 Speaker 1: think that guy might have thought I was actually trying 180 00:09:06,720 --> 00:09:09,240 Speaker 1: to sell him solar panels, like he looked kind of wary. 181 00:09:09,280 --> 00:09:12,480 Speaker 1: He's like, are you another one of those shady solar 182 00:09:12,520 --> 00:09:18,000 Speaker 1: salesman discounts. They are pretty shady quote unquote, that's right exactly. 183 00:09:18,120 --> 00:09:20,160 Speaker 1: Their business wouldn't stand up to sunlight. You have to 184 00:09:20,160 --> 00:09:23,120 Speaker 1: be pretty bright. And there was one folk, one guy 185 00:09:23,120 --> 00:09:25,559 Speaker 1: who actually had a pretty solid answer. Was this your 186 00:09:25,640 --> 00:09:29,200 Speaker 1: physics student sale and slash sale instructor? It was not. 187 00:09:29,720 --> 00:09:32,080 Speaker 1: Actually that was my eleven year old son, who I 188 00:09:32,120 --> 00:09:35,160 Speaker 1: think overheard me talking about solar sales to somebody else 189 00:09:35,200 --> 00:09:37,360 Speaker 1: before I asked him, so he had a preview of 190 00:09:37,400 --> 00:09:40,120 Speaker 1: the answer and just wound wanted to sound smart. You're 191 00:09:40,160 --> 00:09:44,000 Speaker 1: saying your son cheated, I'm saying I asked him the question, 192 00:09:44,000 --> 00:09:45,720 Speaker 1: and he knew the answer, and so he answered it. 193 00:09:48,800 --> 00:09:51,079 Speaker 1: That's right, it's it wasn't a test. Yeah, he had 194 00:09:51,120 --> 00:09:53,200 Speaker 1: a bit more of a head start than the rest 195 00:09:53,200 --> 00:09:55,200 Speaker 1: of the other folks that we asked. So, um, it's 196 00:09:55,200 --> 00:09:56,880 Speaker 1: not something that a lot of people seem to know 197 00:09:56,920 --> 00:09:59,679 Speaker 1: about or recognize the name of. That's right. It's not 198 00:09:59,720 --> 00:10:01,640 Speaker 1: a in concept. And that surprised me a little bit 199 00:10:01,720 --> 00:10:05,280 Speaker 1: because I thought that people had heard more about like 200 00:10:05,320 --> 00:10:07,600 Speaker 1: how to move through space or the kinds of engines 201 00:10:07,679 --> 00:10:10,000 Speaker 1: you might use. But I guess not which makes an 202 00:10:10,040 --> 00:10:12,880 Speaker 1: excellent topic for today's podcast. Yeah. Well, I have to 203 00:10:12,920 --> 00:10:16,960 Speaker 1: admit my only reference to a solar sale powered spaceship 204 00:10:17,240 --> 00:10:19,480 Speaker 1: is from Star Wars. Do they do solar sales? And 205 00:10:19,520 --> 00:10:21,200 Speaker 1: Star Wars? I don't even remember that. I thought they 206 00:10:21,240 --> 00:10:24,720 Speaker 1: all had ion engines and stuff. Yeah, I know. I mean, 207 00:10:24,760 --> 00:10:27,800 Speaker 1: if you if you've watched the prequels, which I'm sure 208 00:10:27,880 --> 00:10:30,720 Speaker 1: we can get into a whole episode about. But count 209 00:10:30,720 --> 00:10:33,640 Speaker 1: Dooku with that character has rise around in a ship 210 00:10:33,760 --> 00:10:36,840 Speaker 1: that has solar sales or what looks like what looked 211 00:10:36,880 --> 00:10:38,960 Speaker 1: like solar sales. Oh my gosh. Why you have like 212 00:10:38,960 --> 00:10:41,920 Speaker 1: an encyclopedic knowledge of all the ships in every science 213 00:10:41,920 --> 00:10:46,120 Speaker 1: fiction movie ever. That's that's impressive. And I have an 214 00:10:46,200 --> 00:10:50,719 Speaker 1: encyclopedic knowledge of all NERD movies. So that's what That's 215 00:10:50,760 --> 00:10:52,360 Speaker 1: what you do it for In the afternoon when you're 216 00:10:52,480 --> 00:10:54,400 Speaker 1: not feeling in the mood to do cartooning, it's like 217 00:10:54,679 --> 00:10:57,800 Speaker 1: turn on some science fiction movie. Yeah, isn't that what 218 00:10:57,840 --> 00:11:02,719 Speaker 1: everybody does? Yes, yes, that is exactly what everybody does 219 00:11:02,760 --> 00:11:05,520 Speaker 1: in the middle of the afternoon. Um, no, but you're right, 220 00:11:05,600 --> 00:11:07,959 Speaker 1: these things are in science fiction. Um. I've read lots 221 00:11:08,000 --> 00:11:11,400 Speaker 1: of books with solar sale powered chips in them. Uh, 222 00:11:11,440 --> 00:11:13,840 Speaker 1: it's a pretty common idea in terms of like how 223 00:11:13,880 --> 00:11:15,120 Speaker 1: to get from here to there. And you know what, 224 00:11:15,160 --> 00:11:17,400 Speaker 1: we don't have that many ideas for how to get 225 00:11:17,480 --> 00:11:20,160 Speaker 1: from one planet to another or one star to another, 226 00:11:20,640 --> 00:11:22,679 Speaker 1: and so it's on a pretty short list. Well, this 227 00:11:22,720 --> 00:11:24,480 Speaker 1: is how it kind of worked in Star Wars. So 228 00:11:24,600 --> 00:11:27,600 Speaker 1: count get on this ship. He takes off, he flies 229 00:11:27,679 --> 00:11:30,880 Speaker 1: up into orbit or space, and then he like unfurls 230 00:11:30,960 --> 00:11:35,199 Speaker 1: this huge giant sail, this like giant sheet that looks 231 00:11:35,280 --> 00:11:37,640 Speaker 1: kind of like it's made out of gold, and then 232 00:11:37,679 --> 00:11:40,280 Speaker 1: then he starts going. So it's like he's it's like 233 00:11:40,280 --> 00:11:43,120 Speaker 1: he opened a giant umbrella and then that pushed him forward. Yeah, 234 00:11:43,160 --> 00:11:46,680 Speaker 1: that's basically a solar sales are giant umbrellas. Podcast over, 235 00:11:47,000 --> 00:11:53,600 Speaker 1: you nailed it Star Wars for the wind. Yeah, let's 236 00:11:53,600 --> 00:11:55,760 Speaker 1: get into it, Daniel. What is a solar sale? So 237 00:11:55,800 --> 00:11:59,200 Speaker 1: a solar sale is an enormous flat sheet, just like 238 00:11:59,240 --> 00:12:01,600 Speaker 1: a sail on a sale boat. Um, and the thing 239 00:12:01,640 --> 00:12:05,079 Speaker 1: that it captures is not wind like in air, because 240 00:12:05,080 --> 00:12:07,079 Speaker 1: there is no wind in space and it's not the 241 00:12:07,120 --> 00:12:10,360 Speaker 1: solar wind because the solar wind member is protons being 242 00:12:10,360 --> 00:12:13,520 Speaker 1: shot out by the Sun and those could push the sail, 243 00:12:13,559 --> 00:12:15,520 Speaker 1: but there's just not that much of them. There's just 244 00:12:15,559 --> 00:12:17,320 Speaker 1: not that many of them. There's not enough of them. 245 00:12:17,640 --> 00:12:20,880 Speaker 1: What is capturing is light. So the light from the 246 00:12:20,920 --> 00:12:23,520 Speaker 1: sun is zooming out from the Sun and it's carrying 247 00:12:23,600 --> 00:12:25,680 Speaker 1: energy with it, and we'll dig into that in a moment. 248 00:12:25,720 --> 00:12:28,079 Speaker 1: But photons have momentum, and so what happens when they 249 00:12:28,280 --> 00:12:31,240 Speaker 1: hit the sail is that they give it a little push, 250 00:12:31,440 --> 00:12:34,160 Speaker 1: and you get enough little pushes and you can actually 251 00:12:34,200 --> 00:12:36,320 Speaker 1: get going somewhere. So this is a real thing, like 252 00:12:36,400 --> 00:12:41,160 Speaker 1: people have built these, Like there are functioning solar wind 253 00:12:42,040 --> 00:12:44,760 Speaker 1: sailboats out there in space. Um, yes, this is a 254 00:12:44,840 --> 00:12:47,400 Speaker 1: real thing. It's like physics says, there's no reason why 255 00:12:47,440 --> 00:12:51,079 Speaker 1: I shouldn't work. People have big plans to make huge 256 00:12:51,080 --> 00:12:53,320 Speaker 1: solar sales that can go all around the Solar System 257 00:12:53,400 --> 00:12:57,000 Speaker 1: or maybe even to other stars. And somebody has actually 258 00:12:57,040 --> 00:12:59,160 Speaker 1: built one of these things and made it work. The 259 00:12:59,280 --> 00:13:03,079 Speaker 1: Japanese they launched one um several years ago and showed 260 00:13:03,080 --> 00:13:05,520 Speaker 1: that it actually worked. Like the physics isn't just theoretical, 261 00:13:05,600 --> 00:13:08,280 Speaker 1: Like there is one thing out there that's solar sailing 262 00:13:08,360 --> 00:13:13,000 Speaker 1: right now, that's pretty cool the Japanese. The Japanese, nice job. 263 00:13:13,320 --> 00:13:16,920 Speaker 1: But the thing about solar sales is that it's gentle, right, 264 00:13:17,160 --> 00:13:20,600 Speaker 1: It's not really really powerful winds of light out there 265 00:13:20,640 --> 00:13:22,920 Speaker 1: for you to capture with your sales. So if you 266 00:13:22,960 --> 00:13:26,800 Speaker 1: have like even a really big sale, like eight hundred 267 00:13:26,840 --> 00:13:30,080 Speaker 1: meters by eight hundred meters, which is you know, enormous, right, 268 00:13:30,559 --> 00:13:33,760 Speaker 1: then that only gets five newton's of force, And five 269 00:13:33,760 --> 00:13:36,679 Speaker 1: newtons is not that much. It's like how much you know, 270 00:13:36,960 --> 00:13:39,800 Speaker 1: a fourth there isn't like a one pound object on Earth, 271 00:13:40,280 --> 00:13:43,440 Speaker 1: So like a one pound rock, you know, think about 272 00:13:43,440 --> 00:13:45,400 Speaker 1: how much that feels in your hand. That's the force 273 00:13:45,800 --> 00:13:48,280 Speaker 1: of the Earth's gravity on a one pound rock. That's 274 00:13:48,280 --> 00:13:51,199 Speaker 1: the same amount of force that the Sun would push 275 00:13:51,320 --> 00:13:54,720 Speaker 1: on a eight hundred meter by eight hundred meters sail 276 00:13:55,000 --> 00:13:58,200 Speaker 1: about the distance from of the Earth, which is huge, right, 277 00:13:58,240 --> 00:14:00,920 Speaker 1: I mean it's a several city blocks. Yeah, that is 278 00:14:00,960 --> 00:14:04,160 Speaker 1: not a small thing to build and to unferral and 279 00:14:04,200 --> 00:14:07,040 Speaker 1: to keep from getting shredded right by like micro meteorites 280 00:14:07,120 --> 00:14:10,360 Speaker 1: or whatever. But you're saying if I made a tarp 281 00:14:10,960 --> 00:14:14,959 Speaker 1: that was about a kilometer on each side over Manhattan, 282 00:14:15,679 --> 00:14:17,600 Speaker 1: it would get pushed down not just by the weight 283 00:14:17,600 --> 00:14:20,400 Speaker 1: of it, but also by the sun that's hitting it. Yes, exactly, 284 00:14:20,640 --> 00:14:24,400 Speaker 1: And every time a photon hits you, you're getting pushed. Like. 285 00:14:24,440 --> 00:14:29,000 Speaker 1: Photons are actually pushy. They are kind of rude, aren't they. 286 00:14:29,240 --> 00:14:31,280 Speaker 1: They just like zoom along wherever they want to go. 287 00:14:31,360 --> 00:14:33,840 Speaker 1: They don't ask questions, they don't take turns, or they 288 00:14:33,880 --> 00:14:37,600 Speaker 1: just going straight lines wherever they need to know. Photons 289 00:14:37,680 --> 00:14:40,320 Speaker 1: care momentum, and every time they hit something, they give 290 00:14:40,360 --> 00:14:42,200 Speaker 1: it a little push. So when you turn, when you 291 00:14:42,200 --> 00:14:44,640 Speaker 1: flip the switch and turn on the light, you get 292 00:14:44,680 --> 00:14:47,440 Speaker 1: pushed down a tiny little bit. And you might think, what, 293 00:14:47,680 --> 00:14:50,040 Speaker 1: I can't feel it, And you're right because it's a 294 00:14:50,040 --> 00:14:53,120 Speaker 1: small effect, which is why solar sales are very gentle, 295 00:14:53,200 --> 00:14:55,360 Speaker 1: and you need a huge one to add up to 296 00:14:55,400 --> 00:14:58,480 Speaker 1: any measurable force. Well, let's step us through a little 297 00:14:58,520 --> 00:14:59,880 Speaker 1: bit of how this works. I mean, so you're saying, 298 00:14:59,880 --> 00:15:02,080 Speaker 1: if I take a flashlight and I flash it at you, 299 00:15:02,360 --> 00:15:05,440 Speaker 1: I am technically kind of pushing you with it. You're 300 00:15:05,440 --> 00:15:09,840 Speaker 1: basically punching me in the face with light. Yeah. Yeah, 301 00:15:09,880 --> 00:15:11,880 Speaker 1: that's that's really me because we don't think of light 302 00:15:11,920 --> 00:15:14,600 Speaker 1: as having substance to it, right, Like you I mean, 303 00:15:14,640 --> 00:15:17,200 Speaker 1: we know we sort of associated with energy and heat 304 00:15:17,280 --> 00:15:20,520 Speaker 1: and warmth, but not um force. That's right. We don't 305 00:15:20,520 --> 00:15:23,120 Speaker 1: think of photons is having mass because they don't, but 306 00:15:23,160 --> 00:15:26,160 Speaker 1: they do have energy, right, Photons are energies is just 307 00:15:26,360 --> 00:15:29,960 Speaker 1: pure energy. And if you have energy, that means you 308 00:15:30,040 --> 00:15:33,520 Speaker 1: have momentum. And it's complicated because we're only used to 309 00:15:33,560 --> 00:15:36,360 Speaker 1: thinking about things having momentum when they have mass. We 310 00:15:36,400 --> 00:15:39,320 Speaker 1: think about you give something momentum because it's heavy and 311 00:15:39,360 --> 00:15:41,320 Speaker 1: it's hard to get going, and once you've pushed it, 312 00:15:41,320 --> 00:15:44,760 Speaker 1: it keeps going. It has momentum. Right, So something that's 313 00:15:44,800 --> 00:15:47,840 Speaker 1: like light and fluffy and you know, weighs nothing, it's 314 00:15:47,840 --> 00:15:50,240 Speaker 1: hard to understand how that can have momentum. Well, I 315 00:15:50,280 --> 00:15:52,240 Speaker 1: think I think we're all pretty familiar with like if 316 00:15:52,280 --> 00:15:54,720 Speaker 1: I shine a flashlight on you or a laser, like 317 00:15:54,800 --> 00:15:57,960 Speaker 1: your body is gonna absorb that energy or you know, 318 00:15:58,040 --> 00:16:00,360 Speaker 1: warm up a little bit or something. But you're saying 319 00:16:00,400 --> 00:16:02,600 Speaker 1: that if I have an atom on my skin and 320 00:16:02,880 --> 00:16:06,040 Speaker 1: you're flashing a flashlight on it, the photons actually sort 321 00:16:06,040 --> 00:16:07,880 Speaker 1: of hit it and the atom wants to go the 322 00:16:07,920 --> 00:16:11,440 Speaker 1: other way. Yes, exactly. Think about what happens with a mirror, right, 323 00:16:11,680 --> 00:16:13,840 Speaker 1: it's a little bit more complicated when the light gets absorbed. 324 00:16:13,840 --> 00:16:15,800 Speaker 1: So let's think about a mirror where the light gets reflected, 325 00:16:16,240 --> 00:16:18,720 Speaker 1: the light zooming in one direction, it hits the mirror, 326 00:16:18,760 --> 00:16:21,200 Speaker 1: and the lights going in the other direction. Right, how 327 00:16:21,240 --> 00:16:24,680 Speaker 1: does the light change direction? Right? What changes the direction 328 00:16:24,680 --> 00:16:27,840 Speaker 1: of the light. It's the mirror. Instead of thinking about 329 00:16:28,280 --> 00:16:30,160 Speaker 1: light in a mirror, think about a ping pong ball 330 00:16:30,200 --> 00:16:32,680 Speaker 1: and a paddle. Right, if you get hit. If a 331 00:16:32,720 --> 00:16:35,400 Speaker 1: ping pong paddle gets hit by the ball, then the 332 00:16:35,440 --> 00:16:38,040 Speaker 1: ball bounces the other direction, but the paddle gets pushed 333 00:16:38,040 --> 00:16:41,720 Speaker 1: back a little bit. Right, That balances the momentum. Momentum 334 00:16:41,760 --> 00:16:44,360 Speaker 1: is conserved. So in the same way, when the light 335 00:16:44,440 --> 00:16:46,800 Speaker 1: hits the mirror, it gives that mirror a little push, 336 00:16:46,800 --> 00:16:49,560 Speaker 1: and the mirror pushes back, and that's what turns the 337 00:16:49,680 --> 00:16:52,360 Speaker 1: light the other direction. And so when light reflects off 338 00:16:52,360 --> 00:16:55,240 Speaker 1: of something, it's giving it a little push. So pure 339 00:16:55,320 --> 00:16:58,800 Speaker 1: energy can push you basically exactly. It can result in 340 00:16:58,960 --> 00:17:01,800 Speaker 1: something wanting to move the other way. That's right. And 341 00:17:01,800 --> 00:17:03,560 Speaker 1: this is one of the cool things in physics when 342 00:17:03,560 --> 00:17:06,080 Speaker 1: you learn that a concept you thought you had a 343 00:17:06,119 --> 00:17:09,320 Speaker 1: firm grasp on, like momentum, is actually just a special 344 00:17:09,359 --> 00:17:11,919 Speaker 1: case of sort of a larger concept. Like we're familiar 345 00:17:11,960 --> 00:17:15,480 Speaker 1: with momentum is mass times velocity. But that's not it's definition. 346 00:17:15,520 --> 00:17:19,480 Speaker 1: That's just how you calculated for slow moving things with mass. 347 00:17:20,040 --> 00:17:22,480 Speaker 1: You can calculate momentum for things that don't have mass, 348 00:17:22,520 --> 00:17:26,080 Speaker 1: because momentum is a larger concept. It's just it captures 349 00:17:26,119 --> 00:17:29,320 Speaker 1: like the quantity of motion of something, not just it's 350 00:17:29,359 --> 00:17:31,639 Speaker 1: mass times velocity. It's just that it's more like the 351 00:17:31,640 --> 00:17:34,399 Speaker 1: total energy. Yeah, but it's fascinating because energy is just 352 00:17:34,440 --> 00:17:37,199 Speaker 1: a number. It doesn't have a direction, right, and physics 353 00:17:37,320 --> 00:17:40,359 Speaker 1: energies is a scaler, not a vector, like it doesn't 354 00:17:40,400 --> 00:17:43,880 Speaker 1: have a direction, just a magnitude, whereas momentum has a direction. 355 00:17:44,119 --> 00:17:46,800 Speaker 1: Like you know, pointed in one direction is different from 356 00:17:46,800 --> 00:17:51,200 Speaker 1: pointed in the other direction. Right, Uh, light has momentum. 357 00:17:51,320 --> 00:17:54,000 Speaker 1: Light has momentum, has energy, and it has momentum and 358 00:17:54,040 --> 00:17:56,520 Speaker 1: it has no mass. One way that some people like 359 00:17:56,640 --> 00:17:59,880 Speaker 1: to think about it is you can think about momentum 360 00:18:00,040 --> 00:18:02,720 Speaker 1: sort of the difference between the energy and the mass. 361 00:18:03,000 --> 00:18:04,960 Speaker 1: Right because in real and relativity we think of the 362 00:18:04,960 --> 00:18:08,040 Speaker 1: total energy as the energy store in the mass plus 363 00:18:08,080 --> 00:18:10,159 Speaker 1: the energy of the momentum. So you can sort of 364 00:18:10,200 --> 00:18:13,200 Speaker 1: invert that equation and say the momentum is the difference 365 00:18:13,440 --> 00:18:15,879 Speaker 1: between the total energy and the mass. And in the 366 00:18:15,880 --> 00:18:18,439 Speaker 1: case of the photon, there is no mass. Momentum just 367 00:18:18,560 --> 00:18:21,719 Speaker 1: comes from the energy, whereas in the case of another particle, right, 368 00:18:21,720 --> 00:18:23,200 Speaker 1: it has a bunch of energy. Some of that is 369 00:18:23,240 --> 00:18:25,040 Speaker 1: in the mass and some of it is in its motion. 370 00:18:25,480 --> 00:18:27,919 Speaker 1: But for the photon, all the energy is just in 371 00:18:27,920 --> 00:18:30,080 Speaker 1: its motion, so it just has momentum and no mass. 372 00:18:30,320 --> 00:18:33,280 Speaker 1: All right. Solar sales are a real thing, and they 373 00:18:33,320 --> 00:18:37,640 Speaker 1: work by taking the momentum that's in light, absorbing it 374 00:18:37,800 --> 00:18:40,399 Speaker 1: and then using that to push you along in space. 375 00:18:40,600 --> 00:18:42,760 Speaker 1: That's right, And it's the light from the Sun that's 376 00:18:42,760 --> 00:18:45,239 Speaker 1: doing this, not the protons from the solar wind. And 377 00:18:45,320 --> 00:18:47,560 Speaker 1: everybody actually can see this if you just have seen 378 00:18:47,560 --> 00:18:50,080 Speaker 1: a comet. You know, comet is just a big ice 379 00:18:50,119 --> 00:18:52,280 Speaker 1: ball and it falls towards the Sun and as it 380 00:18:52,320 --> 00:18:55,280 Speaker 1: does so it gets a big tail, right, and that's 381 00:18:55,320 --> 00:18:57,520 Speaker 1: the tail of it, like the stuff melting and dripping 382 00:18:57,520 --> 00:18:59,960 Speaker 1: out the back, and the tail points in a specific 383 00:19:00,000 --> 00:19:02,920 Speaker 1: direction away from the Sun, not in the direction of motion. 384 00:19:02,960 --> 00:19:05,320 Speaker 1: People think, like, you know, it's like a fuzzy lines 385 00:19:05,400 --> 00:19:08,200 Speaker 1: behind something that's moving fast. But the commet actually always 386 00:19:08,200 --> 00:19:11,680 Speaker 1: points away from the Sun, and that's because of this 387 00:19:11,800 --> 00:19:15,080 Speaker 1: effect of light. That's light pushing the tail of the commet. Really, 388 00:19:15,119 --> 00:19:17,040 Speaker 1: it's not like a trail of a dust that you 389 00:19:17,119 --> 00:19:19,560 Speaker 1: leave behind. No, Because as the common is moving towards 390 00:19:19,600 --> 00:19:21,720 Speaker 1: the Sun, the tail is behind it. But as the 391 00:19:21,760 --> 00:19:24,320 Speaker 1: comet goes around the Sun and then leaves, the tails 392 00:19:24,359 --> 00:19:27,240 Speaker 1: in front of it. Wow, so it shouldn't be called 393 00:19:27,280 --> 00:19:32,080 Speaker 1: the tail once again? Yeah, I guess. Or maybe it's 394 00:19:32,080 --> 00:19:34,040 Speaker 1: like backing away from the Sun as it leaves. It's 395 00:19:34,080 --> 00:19:36,840 Speaker 1: like whoa, that was close. All right, let's get into 396 00:19:37,040 --> 00:19:40,400 Speaker 1: will it work and how how can we make it work? 397 00:19:40,520 --> 00:19:55,040 Speaker 1: But first let's take a quick break. All right. So 398 00:19:55,080 --> 00:19:58,000 Speaker 1: that's solar sales Daniel. That's pretty cool. The question now, 399 00:19:58,040 --> 00:20:00,640 Speaker 1: I think is does it work? If you build it, 400 00:20:00,640 --> 00:20:04,120 Speaker 1: will it take us to other planets and maybe other galaxies? Yeah, 401 00:20:04,160 --> 00:20:05,919 Speaker 1: it's it seems like it will. And you know, we 402 00:20:05,960 --> 00:20:08,080 Speaker 1: know a lot about it. We can do these calculations. 403 00:20:08,080 --> 00:20:10,359 Speaker 1: We know how much light there is, we can calculate 404 00:20:10,640 --> 00:20:13,080 Speaker 1: how it will reflect and how much will be absorbed, 405 00:20:13,160 --> 00:20:15,240 Speaker 1: and we know all the numbers we need. And so 406 00:20:15,280 --> 00:20:18,120 Speaker 1: people have plugged all this stuff into calculations, and they said, 407 00:20:18,560 --> 00:20:21,040 Speaker 1: if you build a solar sale that's like a kilometer 408 00:20:21,119 --> 00:20:24,080 Speaker 1: by a kilometer and you have a really light ship, 409 00:20:24,240 --> 00:20:26,360 Speaker 1: you know, not too heavy, how long would it take 410 00:20:26,400 --> 00:20:29,040 Speaker 1: to get to Mars or to get to Jupiter. And 411 00:20:29,080 --> 00:20:32,040 Speaker 1: the thing you have to understand is that the strength 412 00:20:32,040 --> 00:20:33,960 Speaker 1: of the light, of course, gets weaker as you get 413 00:20:34,000 --> 00:20:36,720 Speaker 1: further from the Sun. So the solar sale is very 414 00:20:36,760 --> 00:20:39,480 Speaker 1: powerful close to the Sun because it's capturing more light, 415 00:20:39,640 --> 00:20:41,320 Speaker 1: and then as you get further and further away from 416 00:20:41,359 --> 00:20:44,119 Speaker 1: the Sun, it gets weaker and weaker. So solar sales 417 00:20:44,160 --> 00:20:46,520 Speaker 1: are great for navigating around the inner parts of a 418 00:20:46,520 --> 00:20:48,800 Speaker 1: solar system. Well, the question I have is, you know 419 00:20:49,119 --> 00:20:52,320 Speaker 1: these sales are catch the rays from the Sun, right, 420 00:20:52,440 --> 00:20:54,479 Speaker 1: they catch the light from the Sun and push it 421 00:20:55,000 --> 00:20:58,199 Speaker 1: get pushed away from the Sun. But what if you 422 00:20:58,200 --> 00:21:01,320 Speaker 1: want to travel towards the Sun are perpendicular to the Sun. 423 00:21:01,480 --> 00:21:02,920 Speaker 1: How would you do that? If you want to move 424 00:21:02,960 --> 00:21:04,800 Speaker 1: towards the Sun, It's not hard, right, you just need 425 00:21:04,880 --> 00:21:06,760 Speaker 1: to use gravity. Right, the Sun is going to pull 426 00:21:06,840 --> 00:21:09,440 Speaker 1: you towards the Sun, so that part is not hard. 427 00:21:09,640 --> 00:21:11,760 Speaker 1: But the only way you can use the sail to 428 00:21:11,840 --> 00:21:14,800 Speaker 1: build energies is moving away from the sun. So you 429 00:21:14,800 --> 00:21:18,400 Speaker 1: can play this game of gravity versus the solar sail 430 00:21:18,680 --> 00:21:20,720 Speaker 1: depending on which way you want to go. If you're 431 00:21:20,720 --> 00:21:22,399 Speaker 1: facing the sun, can you go side? What can it 432 00:21:22,560 --> 00:21:25,760 Speaker 1: push you sideways? Because gravity is pushing me towards the 433 00:21:25,800 --> 00:21:28,720 Speaker 1: sun and the solar sales pushing me away from the sun. 434 00:21:28,960 --> 00:21:32,280 Speaker 1: How do how do I gain speed sideways? WHOA, that's 435 00:21:32,320 --> 00:21:34,760 Speaker 1: a really good question. I haven't even thought about that. 436 00:21:34,840 --> 00:21:37,680 Speaker 1: How do you steer it? Because the photons are only 437 00:21:37,760 --> 00:21:40,199 Speaker 1: coming out from the sun, so can you move in 438 00:21:40,240 --> 00:21:43,679 Speaker 1: a direction that's not out away from the sun. My 439 00:21:43,760 --> 00:21:46,119 Speaker 1: first thought is, let's think about how a sale works 440 00:21:46,119 --> 00:21:48,560 Speaker 1: on a sail boat. Right, on a sail boat, you 441 00:21:48,560 --> 00:21:51,080 Speaker 1: can move in a different direction than the wind if 442 00:21:51,119 --> 00:21:54,200 Speaker 1: you put the sail across from the wind. But the 443 00:21:54,280 --> 00:21:57,520 Speaker 1: problem is a sailboat has a keel, right, has something 444 00:21:57,640 --> 00:22:00,240 Speaker 1: underneath it that keeps it from sliding sideway is and 445 00:22:00,320 --> 00:22:02,640 Speaker 1: so it can only use the part of the wind 446 00:22:02,640 --> 00:22:05,560 Speaker 1: that it wants by pointing in the right direction. A 447 00:22:05,680 --> 00:22:08,399 Speaker 1: solar sale, of course, on a spaceship doesn't have a keel, 448 00:22:09,200 --> 00:22:11,399 Speaker 1: So I first thought you might think, oh, a solar 449 00:22:11,440 --> 00:22:14,200 Speaker 1: sale can only take you in the direction the photons 450 00:22:14,200 --> 00:22:17,200 Speaker 1: are going. Right. Well, let's think about it for a moment. 451 00:22:17,240 --> 00:22:21,040 Speaker 1: What happens if you tilt the sale so that it's 452 00:22:21,080 --> 00:22:24,560 Speaker 1: not pointing um flat away from the sun right, if 453 00:22:24,560 --> 00:22:27,680 Speaker 1: it's at an angle with respect to the photons. You 454 00:22:27,800 --> 00:22:31,080 Speaker 1: might think, well, it doesn't really matter because the photons 455 00:22:31,160 --> 00:22:33,080 Speaker 1: hit it and bounce off, and they're giving a push 456 00:22:33,119 --> 00:22:36,240 Speaker 1: the direction they were going. Right. It's actually a tiny 457 00:22:36,440 --> 00:22:40,719 Speaker 1: bit more complicated. If the photons hit it at an angle, 458 00:22:41,040 --> 00:22:44,400 Speaker 1: then they also bounce off at an angle right. So 459 00:22:45,240 --> 00:22:47,560 Speaker 1: if the photons are coming directly out from the sun 460 00:22:47,640 --> 00:22:49,760 Speaker 1: and they hit flat on the solar sail, then they 461 00:22:49,800 --> 00:22:52,680 Speaker 1: bounced back the opposite direction, and the momentum they have 462 00:22:52,800 --> 00:22:55,800 Speaker 1: given is in the direction they were going. But if 463 00:22:55,840 --> 00:22:57,359 Speaker 1: they come out from the sun and they hit the 464 00:22:57,359 --> 00:23:00,560 Speaker 1: solar cell at an angle right, then they were flecked off. 465 00:23:00,600 --> 00:23:03,160 Speaker 1: Think about light hitting a mirror right. It doesn't come 466 00:23:03,160 --> 00:23:04,879 Speaker 1: back the way it was going. It reflects off at 467 00:23:04,880 --> 00:23:07,680 Speaker 1: an angle, and so the push that it gives is 468 00:23:07,720 --> 00:23:10,960 Speaker 1: actually in the direction that the solar sale was facing. 469 00:23:11,640 --> 00:23:15,040 Speaker 1: So I think that means that you can steer a 470 00:23:15,080 --> 00:23:17,560 Speaker 1: solar sale you just turn it through the way it 471 00:23:17,600 --> 00:23:20,600 Speaker 1: wants to go, and it will catch that part of 472 00:23:20,600 --> 00:23:23,879 Speaker 1: the photons momentum that pushes it in the direction it's facing. 473 00:23:24,160 --> 00:23:26,240 Speaker 1: You can't just point in that direction and drive the 474 00:23:26,240 --> 00:23:27,960 Speaker 1: way you came with your car. You have to take 475 00:23:28,000 --> 00:23:30,680 Speaker 1: an account all these limitations. But you can do it, 476 00:23:30,880 --> 00:23:32,800 Speaker 1: and you can take a pretty heavy load, you know, 477 00:23:32,840 --> 00:23:35,359 Speaker 1: a few tons to mercury, and it just takes a 478 00:23:35,400 --> 00:23:37,520 Speaker 1: few years. If you want to go to Venus, it 479 00:23:37,560 --> 00:23:39,840 Speaker 1: takes you know, about a year. If you want to 480 00:23:39,840 --> 00:23:42,879 Speaker 1: go the other direction, it starts taking longer because the 481 00:23:43,000 --> 00:23:45,880 Speaker 1: radiation from the Sun drops, right, So if you want 482 00:23:45,880 --> 00:23:47,520 Speaker 1: to go to Mars, it takes like a year and 483 00:23:47,520 --> 00:23:50,320 Speaker 1: a half maybe two. Takes like two years to get 484 00:23:50,320 --> 00:23:52,879 Speaker 1: to Jupiter, three to get to Saturn, and then like 485 00:23:52,960 --> 00:23:55,040 Speaker 1: six years and nine years to get out to the 486 00:23:55,520 --> 00:23:58,359 Speaker 1: outer planets. It's a lot of whiskey drinking on board. 487 00:23:59,600 --> 00:24:02,040 Speaker 1: That's your fuel, after all, right, there's no there's no 488 00:24:02,119 --> 00:24:06,120 Speaker 1: solar whiskey, and you'd be using it up. You could 489 00:24:06,160 --> 00:24:09,040 Speaker 1: have burned it to evade that asteroid, but no, you 490 00:24:09,400 --> 00:24:11,280 Speaker 1: had to drink it. Yeah, well, you know, it depends 491 00:24:11,280 --> 00:24:13,200 Speaker 1: on how well you get along with your crewmates, depending 492 00:24:13,440 --> 00:24:15,399 Speaker 1: that determines how much whiskey you have to drink. Can 493 00:24:15,400 --> 00:24:18,080 Speaker 1: you imagine being stuck in a spaceship with your physics 494 00:24:18,080 --> 00:24:20,920 Speaker 1: student for nine years? Tan? No, but I also can't 495 00:24:20,920 --> 00:24:24,119 Speaker 1: imagine being a spaceship by myself for nine years, right, Like, 496 00:24:24,320 --> 00:24:26,320 Speaker 1: what do you think would be easier to handle total 497 00:24:26,359 --> 00:24:29,160 Speaker 1: isolation or being stuck with one person in a tin 498 00:24:29,240 --> 00:24:32,840 Speaker 1: can for nine years? Oh? For me, would definitely be 499 00:24:32,880 --> 00:24:35,760 Speaker 1: by myself. Yeah, you and a big stack of science 500 00:24:35,760 --> 00:24:40,240 Speaker 1: fiction movies, right all you need and a cartooning pad, obviously, 501 00:24:40,400 --> 00:24:43,840 Speaker 1: so I can document my descent into madness, your further 502 00:24:43,920 --> 00:24:47,320 Speaker 1: descent into madness, you ment, surely, that's thank you for 503 00:24:47,520 --> 00:24:52,800 Speaker 1: reminding me. But yes, but what about beyond the Solar system? 504 00:24:52,800 --> 00:24:55,760 Speaker 1: Could you use the solar sale to leave the Solar system? 505 00:24:55,920 --> 00:24:57,640 Speaker 1: You could a little bit. I mean what you can 506 00:24:57,680 --> 00:25:00,280 Speaker 1: do is try One strategy is to just try to 507 00:25:00,280 --> 00:25:03,240 Speaker 1: get going as fast as you can using solar sales 508 00:25:03,320 --> 00:25:05,679 Speaker 1: and gravity, and then zoom off in the direction of 509 00:25:05,680 --> 00:25:08,840 Speaker 1: another star. So you're like you sling shot around the 510 00:25:08,840 --> 00:25:11,680 Speaker 1: Sun to get some speed up, and then as you're 511 00:25:11,720 --> 00:25:14,280 Speaker 1: leaving the Sun, you unfurl your sails and it pushes 512 00:25:14,280 --> 00:25:16,080 Speaker 1: you away from the sun is as hard as you can. 513 00:25:16,400 --> 00:25:18,280 Speaker 1: But then once you leave the solar system, it's really 514 00:25:18,320 --> 00:25:20,080 Speaker 1: going to stop pushing you very much, and so your 515 00:25:20,080 --> 00:25:23,119 Speaker 1: speed doesn't pick up anymore. But you know, if you 516 00:25:23,200 --> 00:25:24,840 Speaker 1: do it right and you have a light enough object, 517 00:25:24,920 --> 00:25:27,359 Speaker 1: you could get up to a reasonable speed UM and 518 00:25:27,440 --> 00:25:29,399 Speaker 1: head off in that direction. Yeah. I mean, at some 519 00:25:29,440 --> 00:25:32,000 Speaker 1: point when you leave the solar system, it's like the 520 00:25:32,000 --> 00:25:34,359 Speaker 1: there's no wind. It's like being on a sailboat with 521 00:25:34,400 --> 00:25:37,760 Speaker 1: no wind. There's nothing to push you anywhere. Yeah, and 522 00:25:37,800 --> 00:25:40,120 Speaker 1: you know there is radiation out there, and there are particles, 523 00:25:40,119 --> 00:25:42,280 Speaker 1: but it's very low density. It's not enough to really 524 00:25:42,680 --> 00:25:45,600 Speaker 1: really boost you. UM. One idea people have, and I 525 00:25:45,640 --> 00:25:48,960 Speaker 1: love this idea because it's so crazy plus ambitious, which 526 00:25:48,960 --> 00:25:53,199 Speaker 1: is my favorite combination, is to basically beam light at 527 00:25:53,240 --> 00:25:55,840 Speaker 1: these things. Like if you're in a solar sailboat and 528 00:25:55,920 --> 00:25:58,680 Speaker 1: you're leaving the solar system, maybe we could like build 529 00:25:58,720 --> 00:26:02,160 Speaker 1: a huge laser and beam the energy at your solar 530 00:26:02,200 --> 00:26:03,960 Speaker 1: sale to give you a push. What if you punch 531 00:26:04,000 --> 00:26:07,359 Speaker 1: a hole through the sale with their laser? Yeah, exactly. 532 00:26:07,359 --> 00:26:10,280 Speaker 1: It can't be too intense. UM. But you know these 533 00:26:10,359 --> 00:26:13,440 Speaker 1: lass these sales will be very reflective, right. They are 534 00:26:14,040 --> 00:26:17,680 Speaker 1: essentially the big sheets of aluminum or maybe plastic that's 535 00:26:17,720 --> 00:26:21,080 Speaker 1: covered with aluminum so that they're super reflective. So if 536 00:26:21,080 --> 00:26:23,879 Speaker 1: it's reflective enough, then even a really really powerful laser 537 00:26:23,920 --> 00:26:27,160 Speaker 1: won't punch a hole, right, because punching a hole means 538 00:26:27,320 --> 00:26:29,960 Speaker 1: the energy gets absorbed and so like melts and destroys 539 00:26:30,000 --> 00:26:32,320 Speaker 1: the sail. If it's reflective enough, then you should be 540 00:26:32,320 --> 00:26:34,720 Speaker 1: able to shoot even a really powerful laser and have 541 00:26:34,800 --> 00:26:37,159 Speaker 1: all the energy to be transferred into the momentum of 542 00:26:37,200 --> 00:26:41,000 Speaker 1: the sail. It's like blowing on a little sailboat. Yeah, exactly. 543 00:26:41,200 --> 00:26:43,200 Speaker 1: Or I'm sure I've seen some science fiction movie where 544 00:26:43,440 --> 00:26:47,080 Speaker 1: somebody like reflects a laser blaster with a mirror. Right, Oh, 545 00:26:47,119 --> 00:26:49,240 Speaker 1: you just have like a pure mirror shoot at it 546 00:26:49,320 --> 00:26:51,840 Speaker 1: and then that pushes you forward. Yeah, if somebody shoots 547 00:26:51,840 --> 00:26:54,119 Speaker 1: you with a laser blaster and you have a mirror, 548 00:26:54,119 --> 00:26:56,560 Speaker 1: you can just reflect their you know, energy pulse or 549 00:26:56,560 --> 00:26:59,320 Speaker 1: whatever back at them. All Right, Well, let's let's get 550 00:26:59,359 --> 00:27:02,840 Speaker 1: into how you actually build a solar sale, even if 551 00:27:02,880 --> 00:27:05,639 Speaker 1: it wasn't on sale. But first let's take a quick break. 552 00:27:18,680 --> 00:27:20,879 Speaker 1: That would be a pretty awesome idea for merch like 553 00:27:21,040 --> 00:27:24,640 Speaker 1: solar sale. Daniel and Jorge solar sale explore the universe 554 00:27:24,640 --> 00:27:27,760 Speaker 1: instead of explain the universe. That'd be pretty cool. What 555 00:27:27,800 --> 00:27:32,480 Speaker 1: do you mean, what will we sail sale sell? We'd 556 00:27:32,520 --> 00:27:35,439 Speaker 1: sell the solar sale like you are. We have a 557 00:27:35,440 --> 00:27:38,080 Speaker 1: shop where we sell t shirts and coffee mugs with 558 00:27:38,119 --> 00:27:40,040 Speaker 1: you know, Daniel and Jorge is playing the universe on it. 559 00:27:40,280 --> 00:27:44,919 Speaker 1: We should add to our Internet merch account a solar 560 00:27:44,960 --> 00:27:48,040 Speaker 1: sale that you can buy. Okay, cool, done, let's do it. 561 00:27:48,119 --> 00:27:50,320 Speaker 1: And then you just get a sheet of aluminum foil? 562 00:27:50,400 --> 00:27:54,680 Speaker 1: Is that the idea? That one kilometer by one kilometers 563 00:27:54,680 --> 00:27:57,520 Speaker 1: wherever loominum foil with your picture on it. There you go, 564 00:27:58,000 --> 00:28:02,320 Speaker 1: and you can sail way into bankruptcy, right, and you 565 00:28:02,359 --> 00:28:05,560 Speaker 1: can shoot a laser at that picture from Earth dual 566 00:28:05,640 --> 00:28:08,800 Speaker 1: purpose aluminum foil. You can wrap your leftovers and go 567 00:28:08,960 --> 00:28:12,960 Speaker 1: into space exactly. But that's basically what a solar sailing is. Right. 568 00:28:13,000 --> 00:28:15,320 Speaker 1: You wanted to be really really big, but you also 569 00:28:15,320 --> 00:28:17,520 Speaker 1: wanted to be really really light. You want your solar 570 00:28:17,520 --> 00:28:19,760 Speaker 1: sailboat to be as light as possible so that all 571 00:28:19,800 --> 00:28:23,360 Speaker 1: that momentum gets turned into speed um. The more massive 572 00:28:23,400 --> 00:28:25,639 Speaker 1: your sailboat, the slower it's going to go for the 573 00:28:25,680 --> 00:28:27,960 Speaker 1: same amount of momentum as you want it really big 574 00:28:28,000 --> 00:28:29,959 Speaker 1: and really thin. I mean, does it matter in the 575 00:28:29,960 --> 00:28:33,440 Speaker 1: long run how much here solar sail ways? Sure it does. Yeah. 576 00:28:33,520 --> 00:28:35,040 Speaker 1: I mean you want to get up to like half 577 00:28:35,040 --> 00:28:36,600 Speaker 1: the speed of light or a quarter of the speed 578 00:28:36,600 --> 00:28:38,880 Speaker 1: of light or something, it's gonna take a lot longer. 579 00:28:38,920 --> 00:28:41,080 Speaker 1: And if you don't have a laser push, then you 580 00:28:41,120 --> 00:28:43,360 Speaker 1: have a limited amount of time to get energy from 581 00:28:43,400 --> 00:28:45,160 Speaker 1: the sun as you want to get up to as 582 00:28:45,200 --> 00:28:47,600 Speaker 1: high as speed as possible. Oh, I mean, but that's 583 00:28:47,600 --> 00:28:51,400 Speaker 1: just in general the same for any acceleration, right, Absolutely, 584 00:28:51,760 --> 00:28:54,920 Speaker 1: the lighter you are, the faster it is to go faster. Yeah, exactly. 585 00:28:54,920 --> 00:28:58,680 Speaker 1: And that's like why people who you know, climb mountains 586 00:28:58,720 --> 00:29:02,080 Speaker 1: on their bicycles or move every tiny little thing that's 587 00:29:02,080 --> 00:29:04,280 Speaker 1: not necessary because they don't want to carry that mass 588 00:29:04,320 --> 00:29:06,520 Speaker 1: up the mountain. You know, I met a guy who's 589 00:29:06,520 --> 00:29:09,520 Speaker 1: climbing Matu Picchu and he like sawt his toothbrush in 590 00:29:09,560 --> 00:29:11,200 Speaker 1: half because he didn't need the bottom half of it. 591 00:29:11,200 --> 00:29:12,920 Speaker 1: And you didn't want to carry that thing up the mountain. 592 00:29:13,680 --> 00:29:15,680 Speaker 1: So yeah, you wanted these your spaceship to be as 593 00:29:15,760 --> 00:29:18,680 Speaker 1: light as possible so you can translate all of that 594 00:29:18,760 --> 00:29:21,800 Speaker 1: momentum into speed. So basically that's all you need is 595 00:29:21,840 --> 00:29:25,560 Speaker 1: just a thin aluminum foil. But usually they showed them, 596 00:29:25,600 --> 00:29:28,920 Speaker 1: show them in movies and and pictures. Is gold It 597 00:29:28,920 --> 00:29:31,000 Speaker 1: looks like gold foil. Does that give you a better 598 00:29:31,000 --> 00:29:34,320 Speaker 1: advantage if it's gold or golden? No? Um, you can't 599 00:29:34,360 --> 00:29:36,719 Speaker 1: just have aluminum foil because aluminium is too brittle. Like 600 00:29:36,760 --> 00:29:38,720 Speaker 1: you try to make a huge sheet of aluminum foil, 601 00:29:38,720 --> 00:29:40,520 Speaker 1: I mean, I can't even get like a one foot 602 00:29:40,560 --> 00:29:43,800 Speaker 1: square of aluminum foil to stay together without tearing. And 603 00:29:43,840 --> 00:29:46,320 Speaker 1: so you try to like fold and then unferral a 604 00:29:46,400 --> 00:29:49,200 Speaker 1: one kilometer square of aluminum foil, It's not gonna work. 605 00:29:49,480 --> 00:29:51,040 Speaker 1: So usually what they do is they have some sort 606 00:29:51,080 --> 00:29:55,000 Speaker 1: of plastic and they spray aluminium coating on it. Um 607 00:29:55,080 --> 00:29:57,120 Speaker 1: And so sometimes that plastic is gold. But I don't 608 00:29:57,120 --> 00:29:59,080 Speaker 1: think there's a reason why that's gold. I think that's 609 00:29:59,080 --> 00:30:01,520 Speaker 1: just to look cool. Right. Well, where are we at then, 610 00:30:01,680 --> 00:30:05,600 Speaker 1: in terms of projects that are trying to use solar 611 00:30:05,640 --> 00:30:08,080 Speaker 1: sales to get us out there? Yeah, So the best 612 00:30:08,080 --> 00:30:11,440 Speaker 1: solar sale ever so far is the Icarus project. Launched 613 00:30:11,480 --> 00:30:14,960 Speaker 1: in by Japan and they had a fourteen by fourteen 614 00:30:15,040 --> 00:30:17,840 Speaker 1: meter solar sale and that sounds small compared to what 615 00:30:17,880 --> 00:30:21,400 Speaker 1: we're talking about like eight eight hundred, but fourteen meters 616 00:30:21,560 --> 00:30:23,760 Speaker 1: is not small, and that's like, you know, the size 617 00:30:23,760 --> 00:30:25,800 Speaker 1: of an apartment. Can I just comment on their choice 618 00:30:25,800 --> 00:30:29,880 Speaker 1: of names, like have they read the whole story of Icarus? 619 00:30:30,120 --> 00:30:33,600 Speaker 1: Do they know how that story ends? I don't know. 620 00:30:33,680 --> 00:30:36,160 Speaker 1: I love I love the hubris in choosing the name 621 00:30:36,320 --> 00:30:40,040 Speaker 1: Icarus for a solar sale project. Right, it's they chose 622 00:30:40,040 --> 00:30:43,160 Speaker 1: a story about Hubris and they did it kind of hubristically. 623 00:30:43,240 --> 00:30:45,719 Speaker 1: They're like thumbing their nose in history. I love it. 624 00:30:46,600 --> 00:30:49,000 Speaker 1: That's not going to happen to us. We're gonna fly 625 00:30:49,200 --> 00:30:51,120 Speaker 1: really close to the sun and nothing bad is going 626 00:30:51,160 --> 00:30:53,760 Speaker 1: to happen to Maybe they're trying to regain the name Acharis. 627 00:30:53,800 --> 00:30:56,600 Speaker 1: They're claiming it back, you know the way some people 628 00:30:56,640 --> 00:30:59,080 Speaker 1: claim back bad words. That we're going to turn this 629 00:30:59,120 --> 00:31:03,000 Speaker 1: new a positive stereotype. Now, they want to redeem Icarus himself. 630 00:31:03,240 --> 00:31:10,640 Speaker 1: That's it exactly. Maybe they're like the descendants of Acharis himself. Yeah, 631 00:31:10,920 --> 00:31:13,200 Speaker 1: so they they're building it. They build it. They're going 632 00:31:13,240 --> 00:31:15,920 Speaker 1: to build it, they built it, they launched it. It worked. 633 00:31:16,000 --> 00:31:18,840 Speaker 1: It's solar sailing. It's zooming around the sun right now. Really, 634 00:31:19,080 --> 00:31:22,959 Speaker 1: it's out there. It's out there, sailing away. It's sipping 635 00:31:23,000 --> 00:31:25,800 Speaker 1: whiskey and looking down on us. And that's the most 636 00:31:25,800 --> 00:31:28,840 Speaker 1: successful solar sale so far. But it's not like a ship, 637 00:31:28,920 --> 00:31:31,640 Speaker 1: right It's like a satellite or a little vessel. Yeah, 638 00:31:31,640 --> 00:31:34,320 Speaker 1: it's it's a little vessel. It's basically just two experiments 639 00:31:34,320 --> 00:31:36,520 Speaker 1: that can we do this thing. Let's see if it 640 00:31:36,520 --> 00:31:38,920 Speaker 1: actually works. Because you know, sometimes in physics, you do 641 00:31:38,960 --> 00:31:41,920 Speaker 1: the calculations, they sound great, and then you know it 642 00:31:41,920 --> 00:31:44,040 Speaker 1: doesn't actually work the way you expected because you forgot 643 00:31:44,040 --> 00:31:46,640 Speaker 1: to account for something. But in this case, it's pretty 644 00:31:46,720 --> 00:31:48,920 Speaker 1: much worked as they expected. And that's a huge boost 645 00:31:49,160 --> 00:31:51,800 Speaker 1: for all the solar sale enthusiasts. I didn't know that 646 00:31:51,840 --> 00:31:54,440 Speaker 1: was such a thing. I'm a solar sale enthusiast. I'm 647 00:31:54,480 --> 00:31:57,400 Speaker 1: a big fan. First of all, I love sailing, but 648 00:31:57,440 --> 00:31:59,480 Speaker 1: I'm a big fan of anything that's going to take 649 00:31:59,560 --> 00:32:02,000 Speaker 1: us to other planets or take us to other stars 650 00:32:02,280 --> 00:32:04,320 Speaker 1: and it isn't going to require a huge ridiculous amount 651 00:32:04,320 --> 00:32:06,440 Speaker 1: of fuel cool Well, uh, and then you were telling 652 00:32:06,440 --> 00:32:11,280 Speaker 1: me there's another cool project called the Breakthrough star Shot project. Yeah, 653 00:32:11,480 --> 00:32:14,280 Speaker 1: they have this awesome idea. They say, let's not send 654 00:32:14,400 --> 00:32:17,400 Speaker 1: one big solar sale, let's build a hundred of like 655 00:32:17,440 --> 00:32:20,640 Speaker 1: a thousand nano sales. So there would be a bunch 656 00:32:20,680 --> 00:32:23,200 Speaker 1: of really small ones and they would push them along 657 00:32:23,240 --> 00:32:26,640 Speaker 1: with lasers between here and Alpha Centauri. The problem with 658 00:32:26,960 --> 00:32:29,960 Speaker 1: building a laser that pushes a big solar sales you 659 00:32:30,000 --> 00:32:32,040 Speaker 1: need a big laser. So they were like, okay, well, 660 00:32:32,080 --> 00:32:34,280 Speaker 1: let's just have a small solar sale that can be 661 00:32:34,320 --> 00:32:36,440 Speaker 1: pushed by a small laser and then just have like 662 00:32:36,440 --> 00:32:40,480 Speaker 1: a tiny little craft. And so they imagine that that 663 00:32:40,480 --> 00:32:43,360 Speaker 1: it would take twenty years to get to Alpha Centauri 664 00:32:43,480 --> 00:32:45,520 Speaker 1: with these little nano sailors, And so they would have 665 00:32:45,560 --> 00:32:48,280 Speaker 1: a giant laser gun on Earth shooting at these things, 666 00:32:49,280 --> 00:32:52,320 Speaker 1: pushing them along, a thousand laser guns pushing on them. Oh, 667 00:32:52,360 --> 00:32:54,720 Speaker 1: each one has their own little laser gun. Yeah, exactly, 668 00:32:54,720 --> 00:32:57,160 Speaker 1: each one needs its own little boost. But the cool 669 00:32:57,200 --> 00:32:59,200 Speaker 1: thing about solar sailing is that you know it's a 670 00:32:59,200 --> 00:33:01,240 Speaker 1: small effect, but it just adds up, and if you're 671 00:33:01,320 --> 00:33:03,520 Speaker 1: traveling for a long time, it's just like more and 672 00:33:03,600 --> 00:33:06,240 Speaker 1: more acceleration. Eventually these things can get up to a 673 00:33:06,400 --> 00:33:08,960 Speaker 1: respectable fraction of the speed of light, you know, so 674 00:33:09,280 --> 00:33:11,880 Speaker 1: they can cross the distances between stars, and then they 675 00:33:11,920 --> 00:33:14,440 Speaker 1: would communicate back what they find. But they can't come back, 676 00:33:14,880 --> 00:33:17,480 Speaker 1: can they. They cannot come back. No, because there's no 677 00:33:17,600 --> 00:33:20,480 Speaker 1: laser system over there for to shoot them back. I 678 00:33:20,520 --> 00:33:22,640 Speaker 1: mean that we're aware of. Maybe they'll get there and 679 00:33:22,640 --> 00:33:25,480 Speaker 1: find Elon Musk has built some you know station over 680 00:33:25,520 --> 00:33:28,800 Speaker 1: there for recharging your solar your solar lasers or something. 681 00:33:29,280 --> 00:33:31,200 Speaker 1: But but no, they it's just a it's a one 682 00:33:31,200 --> 00:33:34,280 Speaker 1: way trip. Well, that's cool. It's like instead of building 683 00:33:34,360 --> 00:33:37,680 Speaker 1: a giant boat, you build a whole bunch of little 684 00:33:37,760 --> 00:33:42,320 Speaker 1: rubber duckies into the river. Kind of exactly. That's gonna be. 685 00:33:42,360 --> 00:33:46,160 Speaker 1: Humanity's first contact with an alien species is the equivalent 686 00:33:46,160 --> 00:33:49,200 Speaker 1: of a rubber ducky. Hi, look at us, We're so impressive. 687 00:33:49,480 --> 00:33:51,600 Speaker 1: This is a little squeezed toy. And then the aliens 688 00:33:51,600 --> 00:33:54,720 Speaker 1: are like, this is a sign of war. That's sorry. 689 00:33:55,040 --> 00:33:57,280 Speaker 1: Maybe the rubber ducky is like holy to them and 690 00:33:57,320 --> 00:33:59,720 Speaker 1: it's offensive that we like through on in their face. 691 00:34:00,040 --> 00:34:02,040 Speaker 1: Plus we probably all of our lasers will be like 692 00:34:02,160 --> 00:34:04,920 Speaker 1: burning their eyeballs down for a twenty years while the 693 00:34:05,280 --> 00:34:07,520 Speaker 1: while the natocrafts are getting there. But if we fill 694 00:34:07,560 --> 00:34:12,239 Speaker 1: them up with whiskey, maybe they'll they'll like it. They'll 695 00:34:12,239 --> 00:34:13,920 Speaker 1: either love it or hate it. They'd be like, what 696 00:34:14,080 --> 00:34:19,280 Speaker 1: Scottish whiskey? I only drink irish? This needs war. Wars 697 00:34:19,280 --> 00:34:21,480 Speaker 1: have been fought over less, I'm sure. All right. So 698 00:34:21,520 --> 00:34:24,640 Speaker 1: that answers Derek's question, who wanted to know how do 699 00:34:24,680 --> 00:34:27,560 Speaker 1: sol of our sales work? And hopefully you guys enjoyed 700 00:34:27,600 --> 00:34:32,520 Speaker 1: that and are inspired to maybe think about taking off sailing. 701 00:34:33,000 --> 00:34:35,759 Speaker 1: That's right, and you know, maybe someday we'll go out 702 00:34:35,760 --> 00:34:38,000 Speaker 1: there and we'll sail among the stars. I think it's 703 00:34:38,000 --> 00:34:40,839 Speaker 1: really beautiful and poetic to imagine using the life from 704 00:34:40,840 --> 00:34:43,359 Speaker 1: the stars themselves to push ourselves from one to the other. 705 00:34:43,719 --> 00:34:46,320 Speaker 1: I really wish that could happen. All right, Thanks for listening, guys, 706 00:34:46,320 --> 00:34:56,200 Speaker 1: see you next time. If you still have a question 707 00:34:56,239 --> 00:34:59,640 Speaker 1: after listening to all these explanations, please drop us a line. 708 00:34:59,680 --> 00:35:01,840 Speaker 1: We'd love to hear from you. You can find us 709 00:35:01,880 --> 00:35:05,680 Speaker 1: at Facebook, Twitter, and Instagram at Daniel and Jorge that's 710 00:35:05,680 --> 00:35:09,080 Speaker 1: one word, or email us at Feedback at Daniel and 711 00:35:09,200 --> 00:35:12,640 Speaker 1: Jorge dot com. Thanks for listening and remember that. Daniel 712 00:35:12,640 --> 00:35:15,160 Speaker 1: and Jorge Explain the Universe is a production of I 713 00:35:15,400 --> 00:35:18,839 Speaker 1: heart Radio. For more podcast from my heart Radio, visit 714 00:35:18,880 --> 00:35:22,360 Speaker 1: the i heart Radio app, Apple Podcasts, or wherever you 715 00:35:22,480 --> 00:35:24,000 Speaker 1: listen to your favorite shows.