1 00:00:08,360 --> 00:00:11,400 Speaker 1: Hey, Daniel, is it true that everything gets stretched out 2 00:00:11,800 --> 00:00:13,360 Speaker 1: as the universe expands? 3 00:00:13,760 --> 00:00:15,600 Speaker 2: That's what the physics tells us so far. 4 00:00:15,760 --> 00:00:18,240 Speaker 1: Yeah, so is that why I feel so tired all 5 00:00:18,280 --> 00:00:19,880 Speaker 1: the time because I'm getting stretched thin? 6 00:00:21,440 --> 00:00:24,320 Speaker 2: You know? I think physics is always your first scapegoat, isn't. 7 00:00:24,120 --> 00:00:27,120 Speaker 1: It, But this time it's kind of true, right. I mean, 8 00:00:27,240 --> 00:00:30,400 Speaker 1: each day my gym gets a little bit further from 9 00:00:30,400 --> 00:00:34,280 Speaker 1: my house, right, so it is making it harder. It's 10 00:00:34,400 --> 00:00:34,960 Speaker 1: stained shape. 11 00:00:35,040 --> 00:00:37,479 Speaker 2: I mean, physics is telling you that the universe is 12 00:00:37,520 --> 00:00:40,360 Speaker 2: getting stretched out, but it's not physics fault. Don't blame 13 00:00:40,400 --> 00:00:40,959 Speaker 2: the messenger. 14 00:00:41,840 --> 00:00:45,360 Speaker 1: Oh well, he could have kept quiet, maybe we wouldn't 15 00:00:45,360 --> 00:00:45,839 Speaker 1: have noticed. 16 00:00:46,880 --> 00:00:49,720 Speaker 2: And that's the end of the podcast. Physics keeps quiet. 17 00:00:51,040 --> 00:01:07,880 Speaker 1: That's a bit of a stretch, though. Hi am for Hey. 18 00:01:07,880 --> 00:01:11,040 Speaker 1: I'm a cartoonist and the author of Oliver's Great Big Universe. 19 00:01:11,400 --> 00:01:14,080 Speaker 2: Hi, I'm Daniel. I'm a particle physicist and a professor 20 00:01:14,120 --> 00:01:16,920 Speaker 2: at UC Irvine, and I want to hear the message 21 00:01:16,959 --> 00:01:19,479 Speaker 2: from physics, whether it's good news or bad news. 22 00:01:19,840 --> 00:01:21,640 Speaker 1: Really, you want to know if like the Earth is 23 00:01:21,680 --> 00:01:24,080 Speaker 1: about to blow up, or if a supernova is about 24 00:01:24,120 --> 00:01:26,200 Speaker 1: to engulf us in flames. 25 00:01:26,440 --> 00:01:32,960 Speaker 2: I definitely want to know that. But that's not bad news. 26 00:01:30,800 --> 00:01:35,600 Speaker 1: Bad news for me and for the human race unless 27 00:01:35,600 --> 00:01:37,280 Speaker 1: you know something we don't know, Daniel. 28 00:01:37,120 --> 00:01:38,480 Speaker 2: No, I'm thinking much bigger. 29 00:01:38,520 --> 00:01:38,720 Speaker 3: You know. 30 00:01:38,840 --> 00:01:42,240 Speaker 2: Cosmic bad news is stuff like, oh, the universe is 31 00:01:42,280 --> 00:01:45,240 Speaker 2: inaccessible to you, or there's lots of dimensions to the 32 00:01:45,319 --> 00:01:47,960 Speaker 2: universe we can never see, or the universe will never 33 00:01:48,040 --> 00:01:52,000 Speaker 2: be understood. That's the kind of philosophically cosmic bad news 34 00:01:52,040 --> 00:01:52,680 Speaker 2: I'm afraid of. 35 00:01:52,880 --> 00:01:55,120 Speaker 1: Oh my goodness, Really that keeps you up at night. 36 00:01:55,520 --> 00:01:58,480 Speaker 2: Absolutely, Yeah. This whole project of physics is based on 37 00:01:58,520 --> 00:02:01,400 Speaker 2: the assumption that the universe follows laws and then we 38 00:02:01,440 --> 00:02:04,640 Speaker 2: can figure them out somehow with our tiny little brains. 39 00:02:05,080 --> 00:02:06,480 Speaker 2: Who knows if that's even true. 40 00:02:06,760 --> 00:02:10,799 Speaker 1: Well, so, what's the physics version of a horror movie? 41 00:02:11,800 --> 00:02:15,799 Speaker 1: Just some scientists coming up and tell you you're never 42 00:02:15,840 --> 00:02:16,680 Speaker 1: gonna know anything. 43 00:02:17,040 --> 00:02:21,400 Speaker 2: No, Now, the physics horror movie is the aliens arrive, 44 00:02:21,919 --> 00:02:24,400 Speaker 2: they explain the universe to us, and we just can't 45 00:02:24,440 --> 00:02:27,680 Speaker 2: get it. We're like, huh, what try again and it 46 00:02:27,800 --> 00:02:28,519 Speaker 2: just never works. 47 00:02:29,800 --> 00:02:31,400 Speaker 1: Or the aliens come and then you ask them what 48 00:02:31,440 --> 00:02:34,239 Speaker 1: are the secrets of the universe? And they go, I'm 49 00:02:34,240 --> 00:02:40,200 Speaker 1: not gonna tell you see you later, No. 50 00:02:41,880 --> 00:02:44,400 Speaker 2: Exactly they want serve man, but. 51 00:02:44,400 --> 00:02:47,680 Speaker 1: Anyways, welcome to our podcast Daniel and Horra Explain the Universe, 52 00:02:47,840 --> 00:02:49,960 Speaker 1: a production of iHeartRadio in. 53 00:02:49,919 --> 00:02:53,320 Speaker 2: Which we die bravely into the task of explaining the universe, 54 00:02:53,360 --> 00:02:57,359 Speaker 2: whether or not it is explainable or understandable, we think 55 00:02:57,400 --> 00:03:00,560 Speaker 2: it's at least worth trying to make sense of everything 56 00:03:00,600 --> 00:03:03,880 Speaker 2: that's happening out there in the cosmos, from tiny little 57 00:03:03,880 --> 00:03:07,240 Speaker 2: particles screaming through space nearly the speed of light, to 58 00:03:07,440 --> 00:03:11,120 Speaker 2: massive black holes gobbling up everything that they can, all 59 00:03:11,120 --> 00:03:13,560 Speaker 2: the way from the tiniest particles to the largest phenomena. 60 00:03:13,639 --> 00:03:17,400 Speaker 2: We try our best to understand the universe, to wrangle 61 00:03:17,400 --> 00:03:20,400 Speaker 2: it into some mathematical sense, and to explain all of 62 00:03:20,440 --> 00:03:21,040 Speaker 2: that to you. 63 00:03:21,680 --> 00:03:24,600 Speaker 1: That's right. We ponder the entire universe, and we wonder 64 00:03:24,639 --> 00:03:26,960 Speaker 1: what it would be like to be out there in space, 65 00:03:27,080 --> 00:03:30,600 Speaker 1: traveling the far reaches of the cosmos, maybe getting stretched 66 00:03:30,639 --> 00:03:34,080 Speaker 1: out by relativity or by the expansion of the universe, 67 00:03:34,600 --> 00:03:38,680 Speaker 1: and hopefully expanding and stretching your mind in the process. 68 00:03:38,920 --> 00:03:42,280 Speaker 2: The whole project of understanding the universe means fitting it 69 00:03:42,320 --> 00:03:45,560 Speaker 2: into your skull, means making it makes sense. The first 70 00:03:45,600 --> 00:03:47,480 Speaker 2: step of that is to figure out what the laws 71 00:03:47,520 --> 00:03:50,520 Speaker 2: are of physics, what are the rules that everything is following, 72 00:03:51,080 --> 00:03:53,840 Speaker 2: and then thinking about whether that clicks together, what happens 73 00:03:53,840 --> 00:03:56,160 Speaker 2: when I apply those rules over here or over there? 74 00:03:56,240 --> 00:03:58,320 Speaker 2: Are there really universal? How does that connect with this 75 00:03:58,440 --> 00:04:01,200 Speaker 2: other idea? I have a lot of physics is just 76 00:04:01,200 --> 00:04:04,160 Speaker 2: trying to stick these puzzle pieces together right right? 77 00:04:04,200 --> 00:04:05,840 Speaker 1: So then the engineer is going to be like, hey, 78 00:04:05,920 --> 00:04:10,560 Speaker 1: can we break that rule? Can we push push the 79 00:04:10,600 --> 00:04:12,880 Speaker 1: limit there? What's going to happen if we try? 80 00:04:12,960 --> 00:04:15,160 Speaker 2: The bridge is going to collapse. That's what's going to happen. 81 00:04:17,400 --> 00:04:19,640 Speaker 2: And that's why I'm glad I'm not an engineer. 82 00:04:19,240 --> 00:04:22,360 Speaker 1: MM, because you're not building bridges, you're just burning them. 83 00:04:23,880 --> 00:04:26,560 Speaker 2: I'm burning mathematical bridges. But when I make a mistake, 84 00:04:26,720 --> 00:04:27,480 Speaker 2: nobody dies. 85 00:04:27,760 --> 00:04:30,520 Speaker 1: Oh really, it seems kind of dangerous to be near 86 00:04:30,520 --> 00:04:34,320 Speaker 1: a particle collider. I mean there's a lot of security 87 00:04:34,320 --> 00:04:34,800 Speaker 1: around those. 88 00:04:35,000 --> 00:04:37,360 Speaker 2: Yeah, that's true, and that's why we rely on accelerator 89 00:04:37,400 --> 00:04:39,960 Speaker 2: physicists to build and operate those things. 90 00:04:41,760 --> 00:04:43,320 Speaker 1: That's why they don't allow me down there. 91 00:04:43,440 --> 00:04:45,880 Speaker 2: Yeah, probably not, But we aren't doing our best to 92 00:04:45,920 --> 00:04:49,200 Speaker 2: develop the most universal laws of physics, we can ones 93 00:04:49,240 --> 00:04:51,960 Speaker 2: that apply to everything under the Sun, including all the 94 00:04:51,960 --> 00:04:54,920 Speaker 2: different kinds of particles that come to us from the Sun. 95 00:04:55,080 --> 00:04:57,400 Speaker 1: Yeah, because the Sun is constantly spewing out not just 96 00:04:57,480 --> 00:04:59,640 Speaker 1: a lot of light and warmth and energy for us 97 00:04:59,680 --> 00:05:02,560 Speaker 1: to joy and to use, but also it's also spewed 98 00:05:02,600 --> 00:05:06,159 Speaker 1: out a ton of other things, particles and uh, lots 99 00:05:06,200 --> 00:05:07,480 Speaker 1: of different kinds of radiation. 100 00:05:07,600 --> 00:05:09,680 Speaker 2: Right, that's right. All the stars out there in the 101 00:05:09,720 --> 00:05:13,760 Speaker 2: universe are pumping out photons, but also a solar wind 102 00:05:14,080 --> 00:05:18,440 Speaker 2: made of all different kinds of particles protons, electrons, neutrinos. 103 00:05:18,839 --> 00:05:20,720 Speaker 2: And we talk a lot about what happens to those 104 00:05:20,760 --> 00:05:24,120 Speaker 2: photons as they move through an expanding universe from galaxies 105 00:05:24,160 --> 00:05:27,440 Speaker 2: moving away from us at very high recession velocities, But 106 00:05:27,480 --> 00:05:30,320 Speaker 2: we don't as often apply those same questions, those same 107 00:05:30,440 --> 00:05:34,360 Speaker 2: rules to the other particles being emitted by those stars. 108 00:05:34,760 --> 00:05:36,960 Speaker 1: So today on the podcast will be tagling the question 109 00:05:42,080 --> 00:05:46,000 Speaker 1: ken neutrinos get red shifted? Now, Daniel, when you talk 110 00:05:46,040 --> 00:05:48,000 Speaker 1: about the solar wind, do you say wind in the 111 00:05:48,040 --> 00:05:51,640 Speaker 1: sense of like a nice breezy summer wind, or do 112 00:05:51,680 --> 00:05:55,279 Speaker 1: you mean it like like a fart, like the sun 113 00:05:55,360 --> 00:05:56,240 Speaker 1: breaks wind. 114 00:05:58,120 --> 00:06:01,359 Speaker 2: Kind of neither of those? Are those the only two options? 115 00:06:02,880 --> 00:06:06,400 Speaker 2: Can I get an option C? Please? Nobody's ever out 116 00:06:06,400 --> 00:06:09,320 Speaker 2: there in space like hmm, I'd like some more solar wind, please. 117 00:06:09,360 --> 00:06:11,640 Speaker 2: I'm overheating. That's never happened. 118 00:06:13,480 --> 00:06:15,680 Speaker 1: Yeah, it's not refreshing out there in space. 119 00:06:15,800 --> 00:06:18,240 Speaker 2: No, I guess it. Yeah, I guess if I have 120 00:06:18,279 --> 00:06:20,599 Speaker 2: to pick between those two. Solar wind is more like 121 00:06:20,640 --> 00:06:23,280 Speaker 2: a fart, because it's kind of unpleasant and dangerous and 122 00:06:23,320 --> 00:06:25,160 Speaker 2: you want to be as far away from it as possible. 123 00:06:25,520 --> 00:06:30,080 Speaker 1: Right, Yeah, it stinky as well. 124 00:06:31,000 --> 00:06:34,600 Speaker 2: You know, people joke about what space smells like, and 125 00:06:34,640 --> 00:06:37,119 Speaker 2: it is partially due to the solar wind, but it's 126 00:06:37,240 --> 00:06:39,800 Speaker 2: also just due to trace other particles that are out 127 00:06:39,800 --> 00:06:42,360 Speaker 2: there that like adhere to the outside of a space 128 00:06:42,400 --> 00:06:45,479 Speaker 2: suit on a spacewalk, which then volatilize as you come 129 00:06:45,520 --> 00:06:48,680 Speaker 2: back inside. People say it smells like barbecue out there 130 00:06:48,680 --> 00:06:49,200 Speaker 2: in space. 131 00:06:49,760 --> 00:06:52,839 Speaker 1: Whoa, and not just because they're cooking in that radiation. 132 00:06:53,880 --> 00:06:56,799 Speaker 2: Yeah, that's right now. If your fart's smelled like barbecue, 133 00:06:57,200 --> 00:06:58,880 Speaker 2: then I don't know. I guess you'd be more popular 134 00:06:58,920 --> 00:06:59,760 Speaker 2: at parties. 135 00:07:00,560 --> 00:07:02,359 Speaker 1: If you fart on the space station. You would not 136 00:07:02,440 --> 00:07:06,880 Speaker 1: be popular up there. It's a pretty closed environment, but 137 00:07:06,920 --> 00:07:10,160 Speaker 1: it must happen. Sounds like a podcast episodedan. 138 00:07:10,560 --> 00:07:12,720 Speaker 2: Sounds like a question for Zach and Kelly, since they're 139 00:07:12,760 --> 00:07:15,800 Speaker 2: an expert in everything unpleasant in space. I'll ask her 140 00:07:15,840 --> 00:07:16,720 Speaker 2: next time she's on. 141 00:07:17,200 --> 00:07:19,679 Speaker 1: There You Go, There you go. What are the physics 142 00:07:19,680 --> 00:07:23,000 Speaker 1: of farts in space? Like how quickly would it dissipate? 143 00:07:23,480 --> 00:07:26,320 Speaker 1: Or like if you're out there and you smell without 144 00:07:26,320 --> 00:07:29,040 Speaker 1: a helmet, would you die first? Or would you smell 145 00:07:29,040 --> 00:07:29,720 Speaker 1: the fart first? 146 00:07:30,480 --> 00:07:33,239 Speaker 2: Or could a really stinky fart cause an international incident 147 00:07:33,320 --> 00:07:35,680 Speaker 2: on the space station which leads to World War three? 148 00:07:35,680 --> 00:07:38,440 Speaker 2: In the end of humanity. You've heard of the butterfly effect. 149 00:07:38,600 --> 00:07:40,480 Speaker 2: Now we're talking about the space fart effect. 150 00:07:40,840 --> 00:07:44,080 Speaker 1: Wow, jeez, it's a dangerous place space. 151 00:07:46,240 --> 00:07:48,080 Speaker 2: Now bring this back to neutrinos. 152 00:07:49,920 --> 00:07:51,800 Speaker 1: Is it like in space no one can hear you fart? 153 00:07:51,920 --> 00:07:55,560 Speaker 2: Or what if your farts were all neutrinos? Here we go, 154 00:07:55,600 --> 00:07:56,920 Speaker 2: I'm bringing this back to the topic. 155 00:07:57,040 --> 00:08:00,480 Speaker 1: Oh you're trying to bring it all right? Right? Smell 156 00:08:00,600 --> 00:08:02,720 Speaker 1: that also or do they have. 157 00:08:02,680 --> 00:08:03,800 Speaker 2: A neutral smell? M? 158 00:08:04,280 --> 00:08:04,440 Speaker 1: Yeah. 159 00:08:04,480 --> 00:08:07,480 Speaker 2: Another question is whether neutrinos have a color and whether 160 00:08:07,520 --> 00:08:10,560 Speaker 2: you could consider them being red shifted or blue shifted? 161 00:08:11,560 --> 00:08:12,040 Speaker 1: All right? 162 00:08:12,120 --> 00:08:12,360 Speaker 2: All right? 163 00:08:12,400 --> 00:08:14,120 Speaker 1: I can tell you're trying to get us back on 164 00:08:14,280 --> 00:08:14,840 Speaker 1: track here. 165 00:08:15,920 --> 00:08:18,640 Speaker 2: This is a physics podcast, not a fart podcast. 166 00:08:18,160 --> 00:08:22,680 Speaker 1: After all, But farts are physical. I dang it, sorry, 167 00:08:23,040 --> 00:08:25,400 Speaker 1: are you trying to ignore part of the physical universe? 168 00:08:26,320 --> 00:08:28,960 Speaker 2: I retract that comment, and I respectfully request we get 169 00:08:29,000 --> 00:08:29,600 Speaker 2: back on track. 170 00:08:32,800 --> 00:08:36,080 Speaker 1: So, yeah, are neutrino's parts of the sun. 171 00:08:36,160 --> 00:08:39,720 Speaker 2: That's the question today, right, The question is whether neutrinos 172 00:08:39,720 --> 00:08:43,079 Speaker 2: can get red shifted the way we know that photons. 173 00:08:42,600 --> 00:08:48,240 Speaker 1: Can, right right, all right, all right, Yeah, it's an 174 00:08:48,280 --> 00:08:51,880 Speaker 1: interesting question. Can I Natrina get red shifted? Because you know, 175 00:08:52,600 --> 00:08:56,040 Speaker 1: the word red shifted we usually applied to light, not neutrinos. 176 00:08:56,160 --> 00:08:59,719 Speaker 2: Yeah, that's right. But if these laws are universal, if 177 00:08:59,720 --> 00:09:02,959 Speaker 2: the same rules apply to everything, then you can ask 178 00:09:03,000 --> 00:09:05,680 Speaker 2: the question, and this is what some listeners have asked me, 179 00:09:06,440 --> 00:09:10,360 Speaker 2: whether the same rules apply to neutrinos from distant stars 180 00:09:10,400 --> 00:09:12,559 Speaker 2: as they do two photons from those stars? 181 00:09:12,920 --> 00:09:15,600 Speaker 1: Well, does that mean that the rules also apply to farts? 182 00:09:17,800 --> 00:09:23,400 Speaker 1: Can Farce get redshift? All right? 183 00:09:23,440 --> 00:09:23,840 Speaker 2: All right? 184 00:09:25,960 --> 00:09:28,480 Speaker 1: Well, as usually, when we're wondering how many people out 185 00:09:28,480 --> 00:09:31,160 Speaker 1: there had thought about Nutrina's and whether or not they 186 00:09:31,200 --> 00:09:32,880 Speaker 1: can get red shifted. 187 00:09:33,440 --> 00:09:35,800 Speaker 2: Thanks very much to everybody who answers questions for this 188 00:09:35,920 --> 00:09:37,800 Speaker 2: segment of the podcast. If you'd like to hear your 189 00:09:37,880 --> 00:09:40,400 Speaker 2: voice for a future episode, please don't be shy. Write 190 00:09:40,400 --> 00:09:43,600 Speaker 2: to me two questions at Danielandjorge dot com. 191 00:09:43,840 --> 00:09:45,560 Speaker 1: So think about it for a minute. Do you think 192 00:09:45,800 --> 00:09:49,520 Speaker 1: neutrinos can get red shifted? Here's what people had to say. 193 00:09:50,520 --> 00:09:53,679 Speaker 2: No, they're not an electron back that spectrum. 194 00:09:53,840 --> 00:09:58,480 Speaker 1: I think yes, neutrinos have la a proton away from 195 00:09:58,720 --> 00:10:01,480 Speaker 1: and if there's an ext arting body coming from there, 196 00:10:01,800 --> 00:10:03,160 Speaker 1: the camera just shifted, I think. 197 00:10:03,720 --> 00:10:06,480 Speaker 4: I assume this is to do with quantum mechanics and 198 00:10:06,520 --> 00:10:08,800 Speaker 4: how particles have a frequency. 199 00:10:11,600 --> 00:10:12,400 Speaker 2: What rechhift. 200 00:10:12,559 --> 00:10:14,640 Speaker 4: That just means like the frequency gets stretched, I think, 201 00:10:14,679 --> 00:10:17,800 Speaker 4: So I guess yeah, it can happen. I don't know 202 00:10:17,880 --> 00:10:18,480 Speaker 4: how or why. 203 00:10:19,400 --> 00:10:21,760 Speaker 3: I don't see why not, but I know the problem 204 00:10:21,760 --> 00:10:24,280 Speaker 3: with them is that they're just so hard to see. 205 00:10:25,000 --> 00:10:27,760 Speaker 3: They seem to pass through just about everything, and I 206 00:10:27,800 --> 00:10:31,120 Speaker 3: know there's a few different kinds. So I guess yes 207 00:10:31,559 --> 00:10:36,199 Speaker 3: they could, But how would you detect that? I'm not sure? 208 00:10:37,000 --> 00:10:41,560 Speaker 1: All right, Well, some pretty interesting answers sort of in 209 00:10:41,600 --> 00:10:45,000 Speaker 1: the range of why not. Who knows? 210 00:10:45,559 --> 00:10:48,319 Speaker 2: Yeah, some people saying yeah, they're a particle like everything else. 211 00:10:48,440 --> 00:10:51,320 Speaker 2: Other people saying no, that only applies to photons and 212 00:10:51,360 --> 00:10:53,439 Speaker 2: things in the electromagnetic spectrum. 213 00:10:53,559 --> 00:10:57,640 Speaker 1: Hmmm, all right, well, let's dig into it, Daniel. Let's 214 00:10:57,679 --> 00:10:59,640 Speaker 1: recap first of all, what is a neutrino. 215 00:11:00,080 --> 00:11:03,359 Speaker 2: Neutrinos are some of the weirdest and most fascinating particles 216 00:11:03,440 --> 00:11:06,559 Speaker 2: in the universe because they're sort of like an extreme 217 00:11:06,679 --> 00:11:09,880 Speaker 2: example of what the universe can do. You know, most 218 00:11:09,880 --> 00:11:12,920 Speaker 2: of the particles we're familiar with, quarks and electrons feel 219 00:11:12,920 --> 00:11:15,640 Speaker 2: a bunch of forces. Quarks feel the strong force and 220 00:11:15,720 --> 00:11:20,520 Speaker 2: the electromagnetic force and the weak force. Electrons feel only 221 00:11:20,559 --> 00:11:23,160 Speaker 2: the electromagnetic force and the weak force. They don't feel 222 00:11:23,160 --> 00:11:27,400 Speaker 2: the strong force. They're neutral in the strong force. Neutrinos 223 00:11:27,440 --> 00:11:29,520 Speaker 2: are like one step further. They're saying, hey, I'm going 224 00:11:29,559 --> 00:11:32,760 Speaker 2: to be neutral also in electromagnetism. I'm going to only 225 00:11:32,880 --> 00:11:36,280 Speaker 2: feel the weak force. So we have examples of particles 226 00:11:36,320 --> 00:11:39,440 Speaker 2: that feel all three quantum forces. The quarks an example 227 00:11:39,440 --> 00:11:42,760 Speaker 2: of particles that feel two of the quantum forces. Electrons 228 00:11:42,800 --> 00:11:46,200 Speaker 2: feel electromagnetism and the weak force, and then an example 229 00:11:46,200 --> 00:11:48,720 Speaker 2: of a particle that feels only one of those forces, 230 00:11:48,840 --> 00:11:52,400 Speaker 2: just the weakest one, the weak force. So neutrinos are 231 00:11:52,400 --> 00:11:54,800 Speaker 2: particles that are out there in the universe that we 232 00:11:54,800 --> 00:11:58,240 Speaker 2: can just baurreally sense, barely interact with, because the only 233 00:11:58,280 --> 00:12:00,440 Speaker 2: way they interact with us is through the way weakest 234 00:12:00,480 --> 00:12:02,559 Speaker 2: force we know about, right. 235 00:12:02,440 --> 00:12:04,960 Speaker 1: Right, But they can still exist, right like, They're still 236 00:12:05,000 --> 00:12:07,360 Speaker 1: made out of real energy in this universe, so you 237 00:12:07,400 --> 00:12:10,560 Speaker 1: can make them. They just sort of ignore us and 238 00:12:10,600 --> 00:12:12,480 Speaker 1: won't talk to us in the ways that most other 239 00:12:12,520 --> 00:12:13,400 Speaker 1: particles talk to us. 240 00:12:13,480 --> 00:12:15,920 Speaker 2: Yeah, exactly. And remember that all of these particles are 241 00:12:15,960 --> 00:12:18,200 Speaker 2: just ripples in fields, and these fields are all on 242 00:12:18,240 --> 00:12:20,360 Speaker 2: top of each other. The way to think about these 243 00:12:20,360 --> 00:12:23,920 Speaker 2: interactions is whether the fields can transfer energy back and forth. 244 00:12:24,240 --> 00:12:27,360 Speaker 2: Then neutrino fields couple very very weakly to all these 245 00:12:27,400 --> 00:12:30,120 Speaker 2: other fields. So it's sort of like having another universe 246 00:12:30,160 --> 00:12:33,160 Speaker 2: on top of us that we can just barely interact with. 247 00:12:33,480 --> 00:12:35,520 Speaker 2: Even if all sorts of crazy stuff is going on, 248 00:12:35,640 --> 00:12:38,480 Speaker 2: even if there's huge numbers of them and enormous amounts 249 00:12:38,480 --> 00:12:42,199 Speaker 2: of mass and energy and velocity, we just barely sense it. 250 00:12:42,679 --> 00:12:44,760 Speaker 2: So it's almost like having a parallel universe. Right on 251 00:12:44,840 --> 00:12:47,240 Speaker 2: top of us. And you know, the even more extreme 252 00:12:47,280 --> 00:12:49,680 Speaker 2: would be dark matter. Dark matter we think might be 253 00:12:49,720 --> 00:12:52,800 Speaker 2: a particle that feels none of these forces, and so 254 00:12:52,840 --> 00:12:55,880 Speaker 2: it's on top of us, but we only sense it gravitationally. 255 00:12:56,520 --> 00:12:59,200 Speaker 2: So neutrino is like almost the extreme limit of that. 256 00:12:59,880 --> 00:12:59,960 Speaker 3: Right. 257 00:13:00,200 --> 00:13:03,040 Speaker 2: They are energy, they're part of our universe, and they 258 00:13:03,080 --> 00:13:05,680 Speaker 2: even have mass. We know the neutrinos are not like 259 00:13:05,760 --> 00:13:08,920 Speaker 2: photons and other massive particles. There is a little bit 260 00:13:08,920 --> 00:13:12,440 Speaker 2: of stuff to them, an incredibly tiny amount of stuff 261 00:13:12,480 --> 00:13:13,440 Speaker 2: to these neutrinos. 262 00:13:13,600 --> 00:13:16,800 Speaker 1: And now, do neutrinos feel gravity? Do we know that. 263 00:13:17,160 --> 00:13:21,720 Speaker 2: Everything with energy feels gravity? Absolutely? Gravity is universal. You 264 00:13:21,800 --> 00:13:25,360 Speaker 2: can't have energy and not feel gravity because remember gravity. 265 00:13:25,480 --> 00:13:27,640 Speaker 1: But have we seen it that we see neutrinos like 266 00:13:28,160 --> 00:13:32,120 Speaker 1: bend by the path of the massive things. 267 00:13:32,280 --> 00:13:35,120 Speaker 2: Oh yeah, great question. We can't observe neutrinos well enough 268 00:13:35,120 --> 00:13:38,320 Speaker 2: to see their path bending, but we know something about 269 00:13:38,320 --> 00:13:41,480 Speaker 2: the massive neutrinos and the number of neutrinos, and that 270 00:13:41,520 --> 00:13:44,360 Speaker 2: affects the overall curvature of space and time, and we 271 00:13:44,400 --> 00:13:47,760 Speaker 2: can see their impact in the early universe and its curvature. 272 00:13:48,360 --> 00:13:50,720 Speaker 2: So we know the neutrinos have energy, and that energy 273 00:13:50,760 --> 00:13:53,640 Speaker 2: does contribute to the curvature of space time. Yeah. M, 274 00:13:54,559 --> 00:13:57,400 Speaker 2: but we haven't seen one bend to gravity, have we 275 00:13:57,679 --> 00:13:59,760 Speaker 2: We have not seen them move in a curved path. No, 276 00:14:00,240 --> 00:14:02,959 Speaker 2: but we know that their energy contributes to the curvature. 277 00:14:03,280 --> 00:14:08,520 Speaker 1: Hmm. Interesting. And is there sort of a perspective on 278 00:14:08,760 --> 00:14:12,160 Speaker 1: why some fields or why some particles interact with some 279 00:14:12,200 --> 00:14:15,439 Speaker 1: forces and not others, or is just sort of how 280 00:14:15,440 --> 00:14:18,600 Speaker 1: the universe was made or how these particles turn out 281 00:14:18,600 --> 00:14:20,240 Speaker 1: to be, you know, like, is there is it like 282 00:14:20,280 --> 00:14:22,600 Speaker 1: a parameter and the equations that is just kind of 283 00:14:22,640 --> 00:14:23,480 Speaker 1: random or what. 284 00:14:23,960 --> 00:14:26,320 Speaker 2: Yeah, it's a great question. Is there an explanation or 285 00:14:26,360 --> 00:14:30,680 Speaker 2: is it just descriptive? Currently it's mostly descriptive. Like we 286 00:14:30,840 --> 00:14:34,240 Speaker 2: say that quarks have a strong charge and electrons don't 287 00:14:34,560 --> 00:14:38,520 Speaker 2: because we see that electrons ignore colored fields. We say 288 00:14:38,560 --> 00:14:41,960 Speaker 2: that neutrinos don't have an electric charge because we see 289 00:14:42,000 --> 00:14:45,600 Speaker 2: that they don't get accelerated by electric fields. So that's 290 00:14:45,600 --> 00:14:47,240 Speaker 2: sort of what we mean by that. It's just a 291 00:14:47,280 --> 00:14:49,880 Speaker 2: description of what we see in these particles. Do we 292 00:14:49,920 --> 00:14:52,200 Speaker 2: do notice a bunch of patterns, like all the quarks 293 00:14:52,240 --> 00:14:54,800 Speaker 2: have the same kinds of charges and electrons and muons 294 00:14:54,800 --> 00:14:57,200 Speaker 2: and towels all have the same electric charge and this 295 00:14:57,320 --> 00:14:59,640 Speaker 2: kind of stuff. So there definitely some patterns and some 296 00:14:59,640 --> 00:15:02,960 Speaker 2: struct sure there, but we definitely do not understand it. 297 00:15:02,960 --> 00:15:06,360 Speaker 2: It's just descriptive. It might be explained by some future 298 00:15:06,400 --> 00:15:08,720 Speaker 2: theory physics that tells us what all these particles are 299 00:15:08,760 --> 00:15:11,840 Speaker 2: made out of, some quiz bits and what knots that 300 00:15:12,120 --> 00:15:14,040 Speaker 2: have fundamental pieces to them, and when you put them 301 00:15:14,040 --> 00:15:17,040 Speaker 2: together in certain ways, or they interact or oscillate in 302 00:15:17,080 --> 00:15:19,360 Speaker 2: certain ways, you get the particles that we see with 303 00:15:19,440 --> 00:15:22,360 Speaker 2: their various properties. But currently we can't explain it. We're 304 00:15:22,400 --> 00:15:24,560 Speaker 2: sort of at the stage of the periodic table one 305 00:15:24,640 --> 00:15:26,920 Speaker 2: hundred and fifty years ago where we see all these 306 00:15:26,960 --> 00:15:29,920 Speaker 2: elements with these different properties, but we don't understand why 307 00:15:29,960 --> 00:15:30,840 Speaker 2: they have that nature. 308 00:15:32,600 --> 00:15:36,240 Speaker 1: And you mentioned there's sort of like ghostly particles, but 309 00:15:36,480 --> 00:15:39,360 Speaker 1: I feel like that maybe understates because there's a huge 310 00:15:39,360 --> 00:15:42,080 Speaker 1: amount of neutrino's going through us right now. Right there's 311 00:15:42,120 --> 00:15:45,640 Speaker 1: like bazillions of them going through our bodies as we speak. 312 00:15:46,200 --> 00:15:49,520 Speaker 2: Yeah, that's right. Neutrinos hardly interact with us, but there's 313 00:15:49,520 --> 00:15:53,000 Speaker 2: no shortage of them because the Sun produces an incredible 314 00:15:53,120 --> 00:15:57,320 Speaker 2: number of neutrinos. Every fusion reaction produces neutrinos, and it 315 00:15:57,360 --> 00:16:01,440 Speaker 2: also produces photons, but those photons are mostly absorbed by 316 00:16:01,520 --> 00:16:04,160 Speaker 2: the Sun, Like the Sun is opaque to most of 317 00:16:04,200 --> 00:16:07,600 Speaker 2: the photons it produces, so those photons are reabsorbed by 318 00:16:07,600 --> 00:16:09,840 Speaker 2: the Sun and it generally heats it up. People talk 319 00:16:09,840 --> 00:16:12,320 Speaker 2: about the photons we see on Earth as having been 320 00:16:12,360 --> 00:16:16,080 Speaker 2: produced in fusion. Technically that's not really accurate. The photons 321 00:16:16,120 --> 00:16:18,560 Speaker 2: produced infusion heat up the Sun and then the Sun 322 00:16:18,680 --> 00:16:22,360 Speaker 2: glows as a black body or because its atmosphere is hot. 323 00:16:22,600 --> 00:16:25,520 Speaker 2: Those are the photons we see, but the neutrinos are different. 324 00:16:25,800 --> 00:16:29,520 Speaker 2: The Sun is transparent to neutrinos the way basically everything 325 00:16:29,600 --> 00:16:32,640 Speaker 2: is transparent to neutrinos. So if a neutrino is made 326 00:16:32,640 --> 00:16:34,920 Speaker 2: at the heart of the Sun, it flies out and 327 00:16:35,000 --> 00:16:38,000 Speaker 2: goes through the Earth and we can observe it directly 328 00:16:38,040 --> 00:16:41,040 Speaker 2: from that fusion process. And there's a huge number of 329 00:16:41,040 --> 00:16:43,920 Speaker 2: them passing through our bodies instead of a billion neutrinos 330 00:16:43,960 --> 00:16:45,960 Speaker 2: per square centimeter per second. 331 00:16:46,640 --> 00:16:49,200 Speaker 1: Yeah, it's huge, and none of them are interacting with 332 00:16:49,280 --> 00:16:51,400 Speaker 1: us or are they a little bit maybe a little 333 00:16:51,400 --> 00:16:54,520 Speaker 1: bit dangerous, Like are some of them maybe knocking on 334 00:16:54,560 --> 00:16:55,720 Speaker 1: some of my DNA. 335 00:16:55,960 --> 00:16:58,680 Speaker 2: Maybe some of them are definitely interacting with you, but 336 00:16:58,680 --> 00:17:01,240 Speaker 2: it's a tiny, tiny number. To give you a sense 337 00:17:01,280 --> 00:17:04,600 Speaker 2: of it, like we have many fewer muons passing through 338 00:17:04,600 --> 00:17:08,760 Speaker 2: our body every second, like one per square centimeter per minute, 339 00:17:08,840 --> 00:17:11,359 Speaker 2: but every single one of those is interacting with your body. 340 00:17:11,400 --> 00:17:13,320 Speaker 2: Like when a muon hits your body, it's like a 341 00:17:13,320 --> 00:17:16,600 Speaker 2: tiny bullet. It's hitting those atoms and it's depositing energy. 342 00:17:16,680 --> 00:17:19,600 Speaker 2: Mostly they're not doing damage, they don't hit anything important, 343 00:17:19,880 --> 00:17:22,439 Speaker 2: and you're fine because they're just these tiny bullets. But 344 00:17:22,520 --> 00:17:26,159 Speaker 2: every single muon does interact with your body. But for neutrinos, 345 00:17:26,200 --> 00:17:28,760 Speaker 2: most of them do not interact with you. So for scale, 346 00:17:28,800 --> 00:17:32,240 Speaker 2: the neutrinos were discovered in an enormous tank underground. We're 347 00:17:32,280 --> 00:17:35,920 Speaker 2: talking about like thousands and thousands and thousands of liters 348 00:17:36,280 --> 00:17:39,240 Speaker 2: of liquid run for a year to see like one 349 00:17:39,400 --> 00:17:43,320 Speaker 2: neutrino bounce off of one of those particles. So neutrino 350 00:17:43,440 --> 00:17:47,200 Speaker 2: interactions with our kind of matter are extraordinarily rare. So yes, 351 00:17:47,280 --> 00:17:49,880 Speaker 2: they are interacting with us, because it's a huge number, 352 00:17:50,119 --> 00:17:52,840 Speaker 2: but it's a tiny, tiny fraction of the neutrinos that 353 00:17:52,880 --> 00:17:56,560 Speaker 2: are created and a tiny overall number of interactions compared 354 00:17:56,600 --> 00:17:59,040 Speaker 2: to like the muons and other particles that are interacting 355 00:17:59,119 --> 00:17:59,399 Speaker 2: with you. 356 00:18:00,160 --> 00:18:01,679 Speaker 1: Now, are these the ones that you can see in 357 00:18:01,760 --> 00:18:04,240 Speaker 1: some science museums where they have like a little chamber 358 00:18:04,280 --> 00:18:06,760 Speaker 1: of water vapor and you see the traces. Are these 359 00:18:06,800 --> 00:18:08,440 Speaker 1: neutrinos or am I thinking of something else? 360 00:18:08,520 --> 00:18:11,199 Speaker 2: Those are mostly muons. Yeah, cloud chambers which you can 361 00:18:11,200 --> 00:18:13,560 Speaker 2: see in science museums, and you can actually build at 362 00:18:13,560 --> 00:18:16,359 Speaker 2: home in your garage without too much trouble. I got 363 00:18:16,400 --> 00:18:18,720 Speaker 2: an email from a listener who was inspired by a 364 00:18:18,760 --> 00:18:20,959 Speaker 2: comment I made a year ago, and she and her 365 00:18:21,000 --> 00:18:23,120 Speaker 2: son built a cloud chamber in her garage and they 366 00:18:23,119 --> 00:18:26,920 Speaker 2: saw muon tracks. So those are mostly muons. Neutrinos. You'd 367 00:18:26,920 --> 00:18:30,000 Speaker 2: need to build an enormous underground chamber of like xenon 368 00:18:30,200 --> 00:18:32,280 Speaker 2: or something in order to see one neutrino, and you 369 00:18:32,280 --> 00:18:35,080 Speaker 2: wouldn't see a track. You'd see the neutrino bumping into 370 00:18:35,119 --> 00:18:38,440 Speaker 2: a normal particle and you'd see the recoil of that particle. 371 00:18:38,920 --> 00:18:41,120 Speaker 2: You can never really see a track of neutrinos because 372 00:18:41,119 --> 00:18:44,400 Speaker 2: that would require multiple interactions of the same neutrino, which 373 00:18:44,440 --> 00:18:48,639 Speaker 2: would be astronomically unlikely. You only ever see like one interaction, 374 00:18:48,800 --> 00:18:51,439 Speaker 2: one push from a neutrino. 375 00:18:51,600 --> 00:18:53,880 Speaker 1: Meons go through the roof of your garage. 376 00:18:53,960 --> 00:18:56,720 Speaker 2: Oh yeah, muons can go through rock. Also, you can 377 00:18:56,720 --> 00:18:59,440 Speaker 2: see muons when you're underground. That's why they build the 378 00:18:59,480 --> 00:19:02,959 Speaker 2: neutrino detectors so deep underground to shield themselves from all 379 00:19:02,960 --> 00:19:06,080 Speaker 2: the muons which can penetrate through meters and meters of rock. 380 00:19:06,320 --> 00:19:09,800 Speaker 1: Mmm. Now, and neutrinos are not just ghostly, but they're 381 00:19:09,960 --> 00:19:13,720 Speaker 1: super duper fast, right, Because they're so little mass, they're 382 00:19:13,760 --> 00:19:16,160 Speaker 1: going almost at the speed of light all the time. 383 00:19:16,280 --> 00:19:19,040 Speaker 2: Yeah. Neutrinos have a tiny, tiny mass, much smaller than 384 00:19:19,080 --> 00:19:21,960 Speaker 2: even electrons, which means when they're produced, if they have 385 00:19:22,080 --> 00:19:25,520 Speaker 2: even a tiny smidge of energy, they're basically going at 386 00:19:25,560 --> 00:19:28,280 Speaker 2: the speed of light, very very close to the speed 387 00:19:28,359 --> 00:19:28,680 Speaker 2: of light. 388 00:19:28,880 --> 00:19:31,320 Speaker 1: Can you slow them down? Like, could you ever hold 389 00:19:31,359 --> 00:19:32,400 Speaker 1: innutrino in your hand? 390 00:19:32,600 --> 00:19:35,320 Speaker 2: Yeah, you could slow neutrinos down. Because they do have mass, 391 00:19:35,320 --> 00:19:39,560 Speaker 2: they can exist at zero velocity. Unlike photons. Photons, there 392 00:19:39,600 --> 00:19:41,920 Speaker 2: is nothing to them if they have no velocity because 393 00:19:41,920 --> 00:19:45,400 Speaker 2: they are just velocity. But if you slow a neutrino down, 394 00:19:45,440 --> 00:19:48,960 Speaker 2: it has mass, right, mass means rest energy, So you 395 00:19:49,000 --> 00:19:51,040 Speaker 2: can be in the same reference frame as a neutrino. 396 00:19:51,080 --> 00:19:53,040 Speaker 2: You could like catch up to a neutrino and look 397 00:19:53,080 --> 00:19:55,880 Speaker 2: at it, or equivalently, you could slow a neutrino down 398 00:19:56,080 --> 00:19:57,160 Speaker 2: and hold it in your hand. 399 00:19:57,240 --> 00:20:00,800 Speaker 1: Yeah, m pretty cool. All right, Well, now the question 400 00:20:00,920 --> 00:20:04,520 Speaker 1: is do neutrinos get red shifted as the universe expands? 401 00:20:04,560 --> 00:20:07,840 Speaker 1: And so let's get into what red shifting is. Can 402 00:20:07,920 --> 00:20:10,840 Speaker 1: it happen for neutrinas and does it make them smell 403 00:20:10,880 --> 00:20:13,199 Speaker 1: like farts or maybe not? We maybe we won't get 404 00:20:13,240 --> 00:20:15,560 Speaker 1: to that in time, but let's give it a try. 405 00:20:16,119 --> 00:20:18,760 Speaker 1: We'll dig into that, but first let's take a quick break. 406 00:20:31,520 --> 00:20:34,000 Speaker 1: All right, we're talking about nutrinas and whether they can 407 00:20:34,000 --> 00:20:38,040 Speaker 1: get red shifted as the universe expands, So those are 408 00:20:38,080 --> 00:20:42,960 Speaker 1: all pretty interesting concept there in one sentence, let's start 409 00:20:42,960 --> 00:20:43,760 Speaker 1: with red shifting. 410 00:20:43,840 --> 00:20:47,199 Speaker 2: What is red shifting and a sentence. Red shifting is 411 00:20:47,240 --> 00:20:50,480 Speaker 2: when a wave gets a longer frequency because it's being 412 00:20:50,480 --> 00:20:54,320 Speaker 2: omitted by something that's moving away from you. So all 413 00:20:54,359 --> 00:20:57,679 Speaker 2: waves have frequency, like sound waves, the sounds you're hearing 414 00:20:57,720 --> 00:21:02,320 Speaker 2: from us have certain frequencies, frequencies and higher frequencies and 415 00:21:02,359 --> 00:21:04,920 Speaker 2: all that kind of stuff. We can describe sound as waves, 416 00:21:04,960 --> 00:21:07,600 Speaker 2: and we can measure the number of times the wave 417 00:21:07,760 --> 00:21:12,240 Speaker 2: waves per second. That's its frequency, just inversely proportional to 418 00:21:12,320 --> 00:21:16,040 Speaker 2: its wavelength, So longer wavelengths lower frequency. 419 00:21:16,200 --> 00:21:17,960 Speaker 1: It sounded like you're trying to hit like a high 420 00:21:18,000 --> 00:21:19,720 Speaker 1: scene and a low S there, Daniel. 421 00:21:20,160 --> 00:21:21,800 Speaker 2: That's sort of like a very low CE and a 422 00:21:21,880 --> 00:21:23,679 Speaker 2: less low C. That's all I'm capable of. 423 00:21:26,119 --> 00:21:28,359 Speaker 1: Low. You can't do falsetto. 424 00:21:28,440 --> 00:21:32,840 Speaker 2: That was my false Oh that was you. I think 425 00:21:32,880 --> 00:21:36,080 Speaker 2: I think you can do better. You're I'm gonna rely 426 00:21:36,240 --> 00:21:38,439 Speaker 2: on our sound editor here, Corey. Can you make this 427 00:21:38,520 --> 00:21:39,560 Speaker 2: sound like a high se. 428 00:21:41,400 --> 00:21:43,720 Speaker 1: Just get a healum balloon there. You don't need. 429 00:21:43,640 --> 00:21:46,480 Speaker 2: Special sects, Chipmunk. Daniel, Yeah, I. 430 00:21:46,480 --> 00:21:49,800 Speaker 1: Think I've seen a video of Morgan Freeman red shifting 431 00:21:49,840 --> 00:21:53,080 Speaker 1: his voice or blue shifting his voice with a healum balloon. 432 00:21:53,720 --> 00:21:54,320 Speaker 2: That's amazing. 433 00:21:54,440 --> 00:21:57,040 Speaker 1: So red shifting is and whenever any kind of wave 434 00:21:57,560 --> 00:22:00,800 Speaker 1: gets stretched out basically right, it becomes a low lower frequency, 435 00:22:01,160 --> 00:22:02,840 Speaker 1: which means bigger wavelengths. 436 00:22:02,920 --> 00:22:05,520 Speaker 2: Yeah, and shift there just tells us that we're changing something. 437 00:22:05,800 --> 00:22:08,760 Speaker 2: And red shift means we're changing it to be more red. 438 00:22:09,160 --> 00:22:13,040 Speaker 2: And red is on the long wavelength low frequency end 439 00:22:13,160 --> 00:22:16,000 Speaker 2: of the visible spectrum. So when we say we're getting 440 00:22:16,080 --> 00:22:20,360 Speaker 2: longer wavelengths or lower frequency, we talk about red shifting, 441 00:22:20,400 --> 00:22:22,880 Speaker 2: and the opposite is blue shifting. If you're making something 442 00:22:22,960 --> 00:22:26,520 Speaker 2: higher frequency or shorter wavelengths, you're making it blue er. 443 00:22:26,880 --> 00:22:30,200 Speaker 2: So red shifting just means you're extending the wavelength, you're 444 00:22:30,240 --> 00:22:31,919 Speaker 2: lowering the frequency, right. 445 00:22:31,840 --> 00:22:33,880 Speaker 1: Right, Although I have to say, I feel like you're 446 00:22:33,920 --> 00:22:36,480 Speaker 1: kind of cheating a little bit here because I don't 447 00:22:36,480 --> 00:22:39,760 Speaker 1: think I've ever heard anyone used to phrase red shifting 448 00:22:39,920 --> 00:22:43,639 Speaker 1: or blue shifting when it comes to anything except light waves. Like, 449 00:22:43,680 --> 00:22:47,840 Speaker 1: nobody ever says, can you give me a blue shifted 450 00:22:47,960 --> 00:22:52,119 Speaker 1: C note or a red shifted D note? Do you 451 00:22:52,200 --> 00:22:52,680 Speaker 1: know what I mean? 452 00:22:53,800 --> 00:22:57,400 Speaker 2: Yeah, that's true. We apply red shifting mostly to astronomical objects, 453 00:22:57,440 --> 00:23:00,640 Speaker 2: and mostly astronomical stuff we see with photon, so that's 454 00:23:00,680 --> 00:23:03,119 Speaker 2: why it's applied there. But you know, if a police 455 00:23:03,160 --> 00:23:06,240 Speaker 2: car is passing by you, as it's driving towards you, 456 00:23:06,280 --> 00:23:09,200 Speaker 2: the wavelengths are shortened, and as it's driving away from you, 457 00:23:09,240 --> 00:23:12,479 Speaker 2: the wavelengths are lengthened, and so you could call that 458 00:23:12,480 --> 00:23:14,320 Speaker 2: blue shifting and red shifting in. 459 00:23:14,240 --> 00:23:16,240 Speaker 1: That case we call it the Doppler effect. 460 00:23:15,880 --> 00:23:18,160 Speaker 2: Right, yeah, exactly, the Doppler effect. 461 00:23:18,160 --> 00:23:20,080 Speaker 1: No, he calls it the red shifting or blue shift. 462 00:23:20,560 --> 00:23:22,879 Speaker 2: But police cars have red and blue lights, so maybe 463 00:23:22,920 --> 00:23:24,200 Speaker 2: somehow I don't know. 464 00:23:25,200 --> 00:23:28,479 Speaker 1: Yeah, yeah, yeah, I figure if I create a if 465 00:23:28,480 --> 00:23:29,800 Speaker 1: you're cheating, Danieler, come on. 466 00:23:30,560 --> 00:23:32,399 Speaker 2: I'm just trying to throw a bunch of random ideas 467 00:23:32,440 --> 00:23:34,280 Speaker 2: at you to distract you from the fact that you're 468 00:23:34,320 --> 00:23:34,840 Speaker 2: right about this. 469 00:23:37,320 --> 00:23:39,680 Speaker 1: Well, I think what you're trying to get at is that, 470 00:23:39,960 --> 00:23:43,120 Speaker 1: you know, anything with a wave, it can get stretched 471 00:23:43,160 --> 00:23:45,959 Speaker 1: out or or it can get shortened, right like anything, 472 00:23:46,119 --> 00:23:49,280 Speaker 1: sound wave, an ocean wave, anything like that can increase 473 00:23:49,359 --> 00:23:54,520 Speaker 1: or decrease in frequency. And for light, that usually means 474 00:23:54,520 --> 00:23:57,200 Speaker 1: that it's changing color, which is where the name red 475 00:23:57,200 --> 00:23:58,720 Speaker 1: shifting and blue shifting come from. 476 00:23:58,920 --> 00:24:02,439 Speaker 2: That's right, And because we're normally applying it to astronomical stuff, 477 00:24:02,680 --> 00:24:06,280 Speaker 2: you know, light from distant galaxies. If that distant galaxy 478 00:24:06,320 --> 00:24:08,439 Speaker 2: is moving away from us, for example, we say that 479 00:24:08,480 --> 00:24:11,160 Speaker 2: it's red shifted and the light from that galaxy looks 480 00:24:11,160 --> 00:24:13,840 Speaker 2: redder than if that galaxy had not been moving away 481 00:24:13,880 --> 00:24:15,879 Speaker 2: from us. And if an object in the sky like 482 00:24:15,920 --> 00:24:19,520 Speaker 2: Andromeda is moving towards us, its light gets blue shifted. 483 00:24:20,000 --> 00:24:22,040 Speaker 2: And you're right that it applies to the wavelength of 484 00:24:22,080 --> 00:24:24,520 Speaker 2: the light and also applies to the color of the 485 00:24:24,600 --> 00:24:27,199 Speaker 2: light as we see it if it's in the visible spectrum, 486 00:24:27,520 --> 00:24:29,920 Speaker 2: and it tells us something about the energy of that light, 487 00:24:30,000 --> 00:24:33,760 Speaker 2: because for light, the wavelength is very closely connected to 488 00:24:33,880 --> 00:24:36,800 Speaker 2: the energy, like red or light is lower energy and 489 00:24:36,880 --> 00:24:38,760 Speaker 2: blue or light is higher energy. 490 00:24:39,080 --> 00:24:42,440 Speaker 1: Right, And this red shifting and blue shifting of light 491 00:24:42,680 --> 00:24:45,200 Speaker 1: out there in the universe happens not just because things 492 00:24:45,200 --> 00:24:47,840 Speaker 1: are moving away from us or towards us, but also 493 00:24:47,960 --> 00:24:50,000 Speaker 1: because the universe is expanding, right. 494 00:24:50,320 --> 00:24:52,520 Speaker 2: Yeah, And these are actually two different ways to talk 495 00:24:52,560 --> 00:24:55,439 Speaker 2: about the same phenomena. You can get confused and think, oh, 496 00:24:55,440 --> 00:24:58,280 Speaker 2: there's two red shifts happening. One that the universe is 497 00:24:58,359 --> 00:25:01,560 Speaker 2: expanding and it makes all waves links longer than the other. 498 00:25:01,680 --> 00:25:04,520 Speaker 2: The galaxies are moving away from us faster and faster 499 00:25:05,000 --> 00:25:07,440 Speaker 2: than the Doppler ship is making their light redder. Those 500 00:25:07,440 --> 00:25:10,320 Speaker 2: are actually two different ways to think about the same phenomenon. 501 00:25:10,680 --> 00:25:13,080 Speaker 2: What's happening there is that your description depends on your 502 00:25:13,119 --> 00:25:16,359 Speaker 2: frame of reference. If you think about the whole universe 503 00:25:16,440 --> 00:25:19,080 Speaker 2: in a single frame, like we're at the center and 504 00:25:19,119 --> 00:25:22,240 Speaker 2: everything is moving away from us. You're measuring the velocity 505 00:25:22,240 --> 00:25:24,919 Speaker 2: of those galaxies relative to us. Then you can use 506 00:25:24,960 --> 00:25:28,560 Speaker 2: the Doppler story to describe what's happening, but instead, in 507 00:25:28,600 --> 00:25:31,840 Speaker 2: a more general relativity sense, you say, well, you can't 508 00:25:31,880 --> 00:25:34,439 Speaker 2: really put everything into a frame because the universe is 509 00:25:34,480 --> 00:25:37,679 Speaker 2: expanding and space is curved between here and other galaxies. 510 00:25:37,920 --> 00:25:40,760 Speaker 2: Which you really have to do is imagine every galaxy 511 00:25:40,880 --> 00:25:44,639 Speaker 2: in its own frame and space increasing between them. And 512 00:25:44,680 --> 00:25:47,680 Speaker 2: in that picture there is really no relative velocity because 513 00:25:47,680 --> 00:25:50,520 Speaker 2: every galaxy has no velocity in its own frame. And 514 00:25:50,600 --> 00:25:52,560 Speaker 2: so what happens to the photons as they go from 515 00:25:52,560 --> 00:25:55,919 Speaker 2: galaxy to galaxy is the expanding space between them is 516 00:25:55,960 --> 00:25:58,520 Speaker 2: doing the work of expansion. It's a good example of 517 00:25:58,560 --> 00:26:00,760 Speaker 2: how you can build physics and lasts to different ways. 518 00:26:00,800 --> 00:26:03,000 Speaker 2: You can start from a few different axioms and end 519 00:26:03,080 --> 00:26:06,520 Speaker 2: up with a different description of the same physical process. 520 00:26:07,119 --> 00:26:09,760 Speaker 1: Right, But it is two separate effects, isn't it, Like 521 00:26:09,840 --> 00:26:12,400 Speaker 1: one is just from its motion and the other one 522 00:26:12,440 --> 00:26:13,960 Speaker 1: is from the expanding of the universe. 523 00:26:14,320 --> 00:26:16,879 Speaker 2: No, it's two descriptions of the same thing. Like in 524 00:26:16,920 --> 00:26:20,119 Speaker 2: the expansion of the universe model, there is no relative velocity. 525 00:26:20,400 --> 00:26:22,960 Speaker 2: In fact, that's more accurate because you can't really talk 526 00:26:22,960 --> 00:26:26,160 Speaker 2: about relative velocity across the whole universe. That's also why 527 00:26:26,200 --> 00:26:28,680 Speaker 2: you end up with sort of nonsense answers, like those 528 00:26:28,720 --> 00:26:31,280 Speaker 2: galaxies are moving away from us faster than the speed 529 00:26:31,320 --> 00:26:34,680 Speaker 2: of light because you're making measurements across two different frames 530 00:26:34,680 --> 00:26:36,320 Speaker 2: where space is curved between them. 531 00:26:36,600 --> 00:26:38,199 Speaker 1: Right, But I feel like there are sort of two 532 00:26:38,240 --> 00:26:40,639 Speaker 1: effects there that can maybe add or subtract, Right, Like, 533 00:26:40,720 --> 00:26:44,840 Speaker 1: if there's a galaxy really far away from us that's 534 00:26:44,880 --> 00:26:49,440 Speaker 1: maybe spinning, for example, then some things they'll be moving 535 00:26:49,520 --> 00:26:51,600 Speaker 1: away from us, and sometimes they'll be moving towards us, 536 00:26:51,760 --> 00:26:54,080 Speaker 1: so they'll be shifting of the light because of that. 537 00:26:54,119 --> 00:26:57,320 Speaker 1: But then also it's really far away, which means that 538 00:26:57,520 --> 00:26:59,600 Speaker 1: on top of that, there's going to be some sort 539 00:26:59,600 --> 00:27:03,080 Speaker 1: of wretch due to the long distances getting longer and longer. 540 00:27:03,359 --> 00:27:05,560 Speaker 2: You can add more layers to it, certainly, like you 541 00:27:05,600 --> 00:27:08,160 Speaker 2: can add not just the fact that these galaxies are 542 00:27:08,200 --> 00:27:11,400 Speaker 2: moving away from us, or equivalently, that space is expanding 543 00:27:11,440 --> 00:27:14,719 Speaker 2: between us, but that also within those frames there is 544 00:27:14,760 --> 00:27:17,280 Speaker 2: some motion relative to the frame itself. So as you 545 00:27:17,320 --> 00:27:20,000 Speaker 2: say galaxies are spinning, and that spinning is what we 546 00:27:20,080 --> 00:27:23,440 Speaker 2: call peculiar motion relative to the frame of the galaxy, 547 00:27:23,480 --> 00:27:26,240 Speaker 2: which is moving with the center of mass of the galaxy. 548 00:27:26,560 --> 00:27:28,960 Speaker 2: And you're right that moving relative to the center mass 549 00:27:28,960 --> 00:27:31,480 Speaker 2: of the galaxy can cause an additional red shift or 550 00:27:31,560 --> 00:27:34,199 Speaker 2: blue shift, so that really is a separate effect. The 551 00:27:34,280 --> 00:27:37,760 Speaker 2: rotation of the galaxy does add another contribution to red 552 00:27:37,760 --> 00:27:39,720 Speaker 2: shifting and blue shifting, and we can see that in 553 00:27:39,760 --> 00:27:42,119 Speaker 2: distant galaxies and we can use it to help measure 554 00:27:42,160 --> 00:27:42,800 Speaker 2: their rotation. 555 00:27:43,200 --> 00:27:45,000 Speaker 1: Right, So there are two effects, right. 556 00:27:45,200 --> 00:27:47,960 Speaker 2: The expansion of the universe and the recession velocity of 557 00:27:47,960 --> 00:27:51,280 Speaker 2: an entire galaxy are two equivalent ways of talking about 558 00:27:51,280 --> 00:27:55,200 Speaker 2: one effect. The rotation of a galaxy does add another effect. Yes, 559 00:27:55,400 --> 00:27:58,679 Speaker 2: you're right that there are multiple contributions to the red shift, 560 00:27:58,760 --> 00:28:01,720 Speaker 2: the motion and the sin but if you're thinking in 561 00:28:01,760 --> 00:28:04,800 Speaker 2: the relative velocity point of view, they're both just contributing 562 00:28:05,000 --> 00:28:09,000 Speaker 2: to the relative velocity. So it's two contributions to one 563 00:28:09,160 --> 00:28:11,840 Speaker 2: red shift effect, not two different effects. 564 00:28:12,119 --> 00:28:14,080 Speaker 1: So how do we measure all this red shifting that's 565 00:28:14,119 --> 00:28:16,240 Speaker 1: going on in the light of the universe. 566 00:28:16,359 --> 00:28:19,640 Speaker 2: Yeah, it's really tricky because you can't stop the galaxies, right, 567 00:28:19,760 --> 00:28:21,840 Speaker 2: or like go to the galaxy and measure like it's 568 00:28:21,920 --> 00:28:23,920 Speaker 2: light that you would measure if you were right there 569 00:28:23,960 --> 00:28:26,439 Speaker 2: next to it. So you have to sort of imagine 570 00:28:27,000 --> 00:28:29,600 Speaker 2: what light you think the galaxy was emitting in its 571 00:28:29,680 --> 00:28:33,760 Speaker 2: own frame and then compare that to what we're seeing. Fortunately, 572 00:28:33,800 --> 00:28:37,600 Speaker 2: galaxies are filled with objects we pretty much understand, stars, 573 00:28:37,600 --> 00:28:40,440 Speaker 2: et cetera, and those are following physics that we pretty 574 00:28:40,480 --> 00:28:42,720 Speaker 2: much understand, so we have a pretty good way to 575 00:28:42,800 --> 00:28:45,680 Speaker 2: predict the light we think a galaxy should be emitting, 576 00:28:45,840 --> 00:28:47,480 Speaker 2: and then we can compare it to the light we're 577 00:28:47,480 --> 00:28:50,400 Speaker 2: seeing from the galaxy and we can tell that it's shifted. 578 00:28:50,760 --> 00:28:53,720 Speaker 2: And specifically, the frequency of the light from these galaxies 579 00:28:54,000 --> 00:28:56,760 Speaker 2: has a few specific handles in it, like a fingerprint 580 00:28:56,960 --> 00:28:59,600 Speaker 2: where we can tell that it's been shifted along Like 581 00:28:59,720 --> 00:29:02,520 Speaker 2: we know that atoms tend to emit light at very 582 00:29:02,560 --> 00:29:06,560 Speaker 2: specific narrow frequency ranges that correspond to the energy levels 583 00:29:06,560 --> 00:29:09,680 Speaker 2: of the atoms. As an electron jumps down one energy 584 00:29:09,720 --> 00:29:12,760 Speaker 2: level around hydrogen, for example, it tends to emit a 585 00:29:12,760 --> 00:29:16,120 Speaker 2: photon with the specific energy of the gap between those 586 00:29:16,200 --> 00:29:19,160 Speaker 2: energy levels. And so if we see light from a 587 00:29:19,200 --> 00:29:22,239 Speaker 2: distant galaxy and it has a huge spike close to 588 00:29:22,320 --> 00:29:25,200 Speaker 2: that energy level, but a little bit shifted. We can say, oh, 589 00:29:25,240 --> 00:29:28,479 Speaker 2: that's probably from hydrogen. It's just shifted a certain amount 590 00:29:28,640 --> 00:29:30,800 Speaker 2: in the red or in the blue. So these like 591 00:29:30,880 --> 00:29:34,080 Speaker 2: standard candles help us understand how the light is shifted 592 00:29:34,080 --> 00:29:35,360 Speaker 2: from these distant galaxies. 593 00:29:35,840 --> 00:29:38,080 Speaker 1: Right. It kind of goes to that idea that stars 594 00:29:38,120 --> 00:29:40,560 Speaker 1: have a sort of fingerprint to them, like the light 595 00:29:40,560 --> 00:29:44,280 Speaker 1: they emit have a very specific pattern of them in 596 00:29:44,320 --> 00:29:47,040 Speaker 1: the fregency spectrum that you can sort of identify what's 597 00:29:47,040 --> 00:29:49,320 Speaker 1: in the star or what it's supposed to have. And 598 00:29:49,320 --> 00:29:52,720 Speaker 1: so if you see that fingerprint kind of smearred, then 599 00:29:52,760 --> 00:29:55,760 Speaker 1: you know that it's red shifted. Right. But then I 600 00:29:55,800 --> 00:29:58,520 Speaker 1: think you can also just generally tell right, because most 601 00:29:58,560 --> 00:30:01,760 Speaker 1: of the light from those things around us is mostly 602 00:30:02,000 --> 00:30:05,440 Speaker 1: you know, a certain color. But I imagine as you 603 00:30:05,480 --> 00:30:07,760 Speaker 1: look out into the universe and things are further away 604 00:30:07,760 --> 00:30:09,600 Speaker 1: from us, things just look redder. 605 00:30:10,000 --> 00:30:12,240 Speaker 2: Yeah, But that's how we can tell the distance to 606 00:30:12,320 --> 00:30:15,200 Speaker 2: things by measuring the red shift. Because there's a correlation 607 00:30:15,280 --> 00:30:18,240 Speaker 2: between how far away things are and how quickly away 608 00:30:18,280 --> 00:30:20,880 Speaker 2: from us they're moving. Then you can use the red 609 00:30:20,880 --> 00:30:23,720 Speaker 2: shift as a measure of distance. Now you have to 610 00:30:23,760 --> 00:30:25,800 Speaker 2: calibrate that is we have a whole episode about the 611 00:30:25,840 --> 00:30:29,840 Speaker 2: cosmic distance ladder to calibrate these things. But generally things 612 00:30:29,880 --> 00:30:32,200 Speaker 2: that are farther away are moving away from us faster. 613 00:30:32,560 --> 00:30:34,440 Speaker 2: So if you measure the red shift of an object, 614 00:30:34,560 --> 00:30:36,920 Speaker 2: you can tell how far away it is or how 615 00:30:36,960 --> 00:30:39,800 Speaker 2: old that light is. But there can also be a 616 00:30:39,840 --> 00:30:43,040 Speaker 2: lot of uncertainty on those measurements because the wider the 617 00:30:43,040 --> 00:30:45,520 Speaker 2: spectrum you measure, like the more of these fingerprints, the 618 00:30:45,520 --> 00:30:49,440 Speaker 2: more of these atomic lines that these spikes that you identify, 619 00:30:49,720 --> 00:30:52,479 Speaker 2: the more accurately you can measure this red shift. This 620 00:30:52,560 --> 00:30:55,200 Speaker 2: is why, for example, when you point multiple telescopes at 621 00:30:55,200 --> 00:30:58,160 Speaker 2: different frequencies at the same galaxy, you can get a 622 00:30:58,200 --> 00:31:01,560 Speaker 2: better measurement for its red shift. Like James Webb recently 623 00:31:01,600 --> 00:31:04,480 Speaker 2: saw some galaxies that were like crazy weird far away. 624 00:31:04,920 --> 00:31:07,240 Speaker 2: Those numbers came from the red shift numbers which were 625 00:31:07,440 --> 00:31:10,360 Speaker 2: pretty uncertain because James Webb didn't have a chance to 626 00:31:10,400 --> 00:31:13,000 Speaker 2: do a broader spectrum and Hubble hadn't looked at it 627 00:31:13,040 --> 00:31:15,640 Speaker 2: yet in a different spectrum. And so that's why sometimes 628 00:31:15,680 --> 00:31:17,920 Speaker 2: when you follow up with more measurements, you can get 629 00:31:18,120 --> 00:31:21,000 Speaker 2: more handles on the light from that galaxy, and that 630 00:31:21,040 --> 00:31:24,240 Speaker 2: revises the red shift measurement, which tells you how far 631 00:31:24,280 --> 00:31:25,480 Speaker 2: away this thing really is. 632 00:31:25,880 --> 00:31:27,720 Speaker 1: Right, But I guess what I'm saying is that that's 633 00:31:27,800 --> 00:31:30,160 Speaker 1: kind of if you want to get really granular and 634 00:31:30,240 --> 00:31:33,080 Speaker 1: know exactly how much the red shifting is. But I wonder, 635 00:31:33,120 --> 00:31:34,960 Speaker 1: and I'm asking if there's a kind of a general 636 00:31:34,960 --> 00:31:37,680 Speaker 1: effect that anyone could affect with their naked eye. You know, 637 00:31:37,760 --> 00:31:39,280 Speaker 1: as the star that we see at night are in 638 00:31:39,280 --> 00:31:41,960 Speaker 1: our galaxy, so I imagine they're not very red shifted. So 639 00:31:42,000 --> 00:31:44,680 Speaker 1: all the light we see from our stars look white 640 00:31:44,960 --> 00:31:49,560 Speaker 1: or yellowish. But if you were to look at the 641 00:31:49,600 --> 00:31:51,960 Speaker 1: rest of this guy, that things are not stars, and 642 00:31:52,360 --> 00:31:54,959 Speaker 1: generally the light we'll see from that is redder. 643 00:31:55,440 --> 00:31:59,360 Speaker 2: Yeah, that's exactly right. And that was Hubble's experience, right, 644 00:31:59,480 --> 00:32:01,040 Speaker 2: you looked up in the night sky. He saw a 645 00:32:01,080 --> 00:32:03,600 Speaker 2: bunch of stars, but he also saw these smudges that 646 00:32:03,640 --> 00:32:06,280 Speaker 2: people thought, oh, those are just like clouds or nebula 647 00:32:06,360 --> 00:32:09,280 Speaker 2: or whatever within our galaxy. But then by calculating the 648 00:32:09,320 --> 00:32:12,240 Speaker 2: red shift and by understanding the relationship between red shift 649 00:32:12,280 --> 00:32:14,480 Speaker 2: and distance, he was like, oh my gosh, look these 650 00:32:14,520 --> 00:32:17,320 Speaker 2: things are redshift. That means they're super duperor far away. 651 00:32:17,520 --> 00:32:20,920 Speaker 2: They're actually other galaxies. So the red shift gives us 652 00:32:20,960 --> 00:32:23,360 Speaker 2: that like third dimension to the night sky rather than 653 00:32:23,440 --> 00:32:26,200 Speaker 2: just seeing like a screen. He gives us the ability 654 00:32:26,240 --> 00:32:28,880 Speaker 2: to project that into the third dimension and understand the 655 00:32:28,960 --> 00:32:30,320 Speaker 2: depth of the night sky. 656 00:32:30,800 --> 00:32:32,600 Speaker 1: Right. Or I wonder if you just put on like 657 00:32:32,800 --> 00:32:37,360 Speaker 1: infrared glasses, right or use an infrared camera, you will 658 00:32:37,480 --> 00:32:40,000 Speaker 1: sort of see more of the rest of the universe. 659 00:32:39,680 --> 00:32:42,840 Speaker 2: Right, yeah, exactly. And that's why James Web, for example, 660 00:32:42,960 --> 00:32:46,240 Speaker 2: is an infrared telescope. They're like, let's focus on the deepest, 661 00:32:46,400 --> 00:32:49,320 Speaker 2: reddest light in the universe, because that's from the most 662 00:32:49,400 --> 00:32:52,800 Speaker 2: distant objects that things were seeing from the early universe. 663 00:32:53,000 --> 00:32:56,280 Speaker 2: That's why you build infrared telescopes exactly, right. 664 00:32:56,160 --> 00:32:58,680 Speaker 1: Right, And if you get really mad, then you'll be 665 00:32:58,680 --> 00:33:01,720 Speaker 1: seen red and so opening your eyes up to more 666 00:33:01,800 --> 00:33:06,560 Speaker 1: of the universe. No, no, not a valid theory. 667 00:33:07,000 --> 00:33:09,320 Speaker 2: Yeah. I mean, if somebody farts really badly at your 668 00:33:09,360 --> 00:33:12,800 Speaker 2: astronomy party, that can make you sopid also yeah. 669 00:33:12,480 --> 00:33:18,640 Speaker 1: Yeah yeah, or in your space station the universe the 670 00:33:18,680 --> 00:33:33,080 Speaker 1: costumers will open up to you. All right. Well, now, 671 00:33:33,120 --> 00:33:36,360 Speaker 1: the main question we're asking here today is whether neutrinos 672 00:33:36,640 --> 00:33:39,000 Speaker 1: can be red shifted, which again I feel like it's 673 00:33:39,040 --> 00:33:43,360 Speaker 1: a little bit of a cheat here because it depends 674 00:33:43,600 --> 00:33:46,200 Speaker 1: on whether you only apply the word redshifting to light, 675 00:33:46,240 --> 00:33:48,280 Speaker 1: which is kind of what some of our listeners brought up. 676 00:33:49,160 --> 00:33:52,120 Speaker 1: So maybe let's settle that right now, Daniel, are you 677 00:33:52,200 --> 00:33:55,440 Speaker 1: expanding the definition of red shifting to things that are 678 00:33:55,480 --> 00:33:55,920 Speaker 1: not light? 679 00:33:56,320 --> 00:33:58,320 Speaker 2: I see, that's a fair question. I hadn't even thought 680 00:33:58,320 --> 00:34:01,200 Speaker 2: about that. To me, redshifting up lies to all sorts 681 00:34:01,240 --> 00:34:04,280 Speaker 2: of waves, even the Doppler effect. Like when that police 682 00:34:04,320 --> 00:34:06,640 Speaker 2: siren is coming at me, I think of that sound 683 00:34:06,720 --> 00:34:10,359 Speaker 2: as blue shifted. I see how blue there implies something 684 00:34:10,400 --> 00:34:13,080 Speaker 2: about visual light, But to me, it's a more general meaning, 685 00:34:13,120 --> 00:34:14,800 Speaker 2: and just that it's changing the frequency. 686 00:34:15,520 --> 00:34:18,640 Speaker 1: Right. But I mean like if a ocean wave got, 687 00:34:18,840 --> 00:34:21,400 Speaker 1: you know, higher frequency, you wouldn't say it got red shifted, 688 00:34:21,440 --> 00:34:24,239 Speaker 1: like nobody would understand you. 689 00:34:24,360 --> 00:34:25,960 Speaker 2: If you got a higher frequency, I would say it 690 00:34:25,960 --> 00:34:28,479 Speaker 2: got blue shifted. Yeah. I think that's pretty cool. Blue 691 00:34:28,480 --> 00:34:31,799 Speaker 2: shifting ocean waves awesome. I'm gonna start saying that everywhere. Now. 692 00:34:32,080 --> 00:34:35,719 Speaker 1: It wouldn't get bluer, right or like you know, a 693 00:34:35,800 --> 00:34:38,840 Speaker 1: high C note, it isn't bluer than a low C note. 694 00:34:38,960 --> 00:34:41,640 Speaker 1: It's sort of a subtle thing. But some of our 695 00:34:41,680 --> 00:34:43,920 Speaker 1: listeners did say that the answer is that it cannot 696 00:34:44,000 --> 00:34:47,000 Speaker 1: because nutrinos are not light, so therefore they can't be 697 00:34:47,080 --> 00:34:47,680 Speaker 1: red shifted. 698 00:34:48,440 --> 00:34:50,600 Speaker 2: I see that that's a fair point. I think blue 699 00:34:50,680 --> 00:34:53,719 Speaker 2: to just mean it's changing in that direction of the frequency. 700 00:34:54,160 --> 00:34:56,439 Speaker 2: You could extend that argument even further and say, like, well, 701 00:34:56,680 --> 00:34:59,879 Speaker 2: that only applies to visible light, because invisible light isn't 702 00:35:00,239 --> 00:35:03,080 Speaker 2: bluer or redder even if its frequency is shifting. 703 00:35:03,320 --> 00:35:05,319 Speaker 1: So what's the answer here for the people who said 704 00:35:05,440 --> 00:35:07,560 Speaker 1: nutinios can be red shifted because they're not light. 705 00:35:07,719 --> 00:35:09,920 Speaker 2: I think we should consider red shifting blue shifting more 706 00:35:10,000 --> 00:35:12,960 Speaker 2: generally to refer to changing the frequency of the waves. 707 00:35:13,200 --> 00:35:17,120 Speaker 1: Okay, so just for today, we're gonna go against what 708 00:35:17,160 --> 00:35:19,200 Speaker 1: most people consider the English language. 709 00:35:19,400 --> 00:35:21,640 Speaker 2: I think that's the accepted meaning of red shifting and 710 00:35:21,640 --> 00:35:24,239 Speaker 2: blue shifting, and I. 711 00:35:24,200 --> 00:35:26,160 Speaker 1: Think we're just going to consider the question of whether 712 00:35:26,200 --> 00:35:30,080 Speaker 1: the wavelength of a nutrinia can change as the universe expands. 713 00:35:30,239 --> 00:35:33,640 Speaker 2: So, according to Wikipedia, which is just looked up and physics, 714 00:35:33,640 --> 00:35:36,640 Speaker 2: a redshift is an increase in the wavelength and corresponding 715 00:35:36,680 --> 00:35:41,239 Speaker 2: decrease in the frequency and energy of electromagnetic radiations. Such 716 00:35:41,280 --> 00:35:43,240 Speaker 2: as light. That's interesting. 717 00:35:46,480 --> 00:35:48,560 Speaker 1: So even Wikipedia disagrees with you. 718 00:35:48,600 --> 00:35:53,239 Speaker 2: Dariel, Yeah, interesting, Yeah, some subtle wrinkles in the definitions here. 719 00:35:54,239 --> 00:35:58,680 Speaker 1: Okay, So then officially, according to Wikipedia, and you know 720 00:35:59,080 --> 00:36:03,720 Speaker 1: most humans who speaks English, the answer to our question 721 00:36:03,760 --> 00:36:05,520 Speaker 1: is no, neutrinus can get red shifted. 722 00:36:06,600 --> 00:36:08,960 Speaker 2: If you define red shifting to only apply to photons, 723 00:36:09,000 --> 00:36:10,000 Speaker 2: then yes, yeah. 724 00:36:10,040 --> 00:36:16,920 Speaker 1: If disregard language, then anything can be anything. But basically, 725 00:36:17,320 --> 00:36:19,680 Speaker 1: I'm saying the listener who said the answer is no, 726 00:36:19,840 --> 00:36:23,160 Speaker 1: because neutrinos are not light, then they're partly right. 727 00:36:23,400 --> 00:36:26,400 Speaker 2: Yeah, they're partly right according to that definition. I'm surprised 728 00:36:26,440 --> 00:36:27,920 Speaker 2: to have to make the argument to you that, like, 729 00:36:28,160 --> 00:36:31,720 Speaker 2: you know, language can be evocative of broader themes and 730 00:36:31,760 --> 00:36:35,320 Speaker 2: deeper ideas that we find patterns of across the universe 731 00:36:35,360 --> 00:36:38,279 Speaker 2: and across phenomena. But you know, to me, I think 732 00:36:38,280 --> 00:36:40,560 Speaker 2: the interesting part of the question is, like, you. 733 00:36:40,520 --> 00:36:42,720 Speaker 1: Mean, you're surprised that you have to be clear about 734 00:36:42,760 --> 00:36:46,080 Speaker 1: what you call things in physics. You're surprised. But at 735 00:36:46,080 --> 00:36:48,160 Speaker 1: this point five years. 736 00:36:47,880 --> 00:36:49,919 Speaker 2: In, yeah, I should learned that should have learned. 737 00:36:51,160 --> 00:36:53,920 Speaker 1: Well, okay, so let's just say the answer is no, 738 00:36:54,040 --> 00:36:57,880 Speaker 1: Nutritius cannot get red shifted because I think even Wikipedia 739 00:36:58,000 --> 00:37:01,160 Speaker 1: agrees that it applies to light only. But it's still 740 00:37:01,160 --> 00:37:04,160 Speaker 1: an interesting question to ask whether neutrinos that are traveling 741 00:37:04,160 --> 00:37:07,560 Speaker 1: out there in space do their wavelengths get stretched out 742 00:37:07,560 --> 00:37:09,320 Speaker 1: by the expansion of the universe. 743 00:37:10,280 --> 00:37:13,560 Speaker 2: Do they get shifted to longer or shorter wavelengths? 744 00:37:14,120 --> 00:37:18,120 Speaker 1: Yeah, do their wavelengths get stretched or squeeze as the 745 00:37:18,200 --> 00:37:20,040 Speaker 1: universe expands? So let's tackle that question. 746 00:37:20,400 --> 00:37:23,560 Speaker 2: So I agree that is right, interesting question. 747 00:37:23,400 --> 00:37:27,040 Speaker 1: Yes, okay, So then so it happens to light because 748 00:37:27,040 --> 00:37:31,000 Speaker 1: the universe is expanding, right, So as it's traveling, it's 749 00:37:31,040 --> 00:37:34,400 Speaker 1: having to travel through more space as it goes along. 750 00:37:34,440 --> 00:37:37,040 Speaker 1: Is that why it stretches, Just because it's sitting in 751 00:37:37,080 --> 00:37:39,840 Speaker 1: space and space is being stretched, its frequency gets stretched. 752 00:37:39,920 --> 00:37:42,959 Speaker 2: Yes, the second one, space itself is getting stretched out, 753 00:37:43,400 --> 00:37:46,560 Speaker 2: and radiation gets stretched out differently than like matter. Does 754 00:37:47,080 --> 00:37:49,920 Speaker 2: you know, electrons sitting in space, you stretch out the space. 755 00:37:49,960 --> 00:37:52,720 Speaker 2: You still have one electron and now you have more space, 756 00:37:53,000 --> 00:37:55,560 Speaker 2: so you have less matter per volume where things get 757 00:37:55,600 --> 00:37:58,800 Speaker 2: diluted in a certain way. The same thing happens to radiation. 758 00:37:58,880 --> 00:38:01,680 Speaker 2: You have one photon in that volume, but that photon's 759 00:38:01,840 --> 00:38:06,280 Speaker 2: energy also decreases because the wavelength of that photon also changes. 760 00:38:06,760 --> 00:38:09,160 Speaker 1: Right, So then the question is do neutrinos have a 761 00:38:09,440 --> 00:38:10,880 Speaker 1: frequency or a wavelength? 762 00:38:11,480 --> 00:38:13,359 Speaker 2: Yeah, So in this sense, you can think of all 763 00:38:13,440 --> 00:38:18,320 Speaker 2: particles as ripples in some field, right, and those ripples 764 00:38:18,360 --> 00:38:21,680 Speaker 2: have frequencies. Like we talked to Mats Dressler about this recently, 765 00:38:21,920 --> 00:38:24,560 Speaker 2: and you can imagine electrons is having like a standing wave, 766 00:38:24,560 --> 00:38:26,919 Speaker 2: which is an oscillation in that field, and a traveling wave, 767 00:38:26,960 --> 00:38:30,120 Speaker 2: which is like the motion of the electron through that field. 768 00:38:30,400 --> 00:38:33,560 Speaker 2: Photons only have a traveling wave because they have no mass. 769 00:38:33,800 --> 00:38:36,799 Speaker 1: Where there's two kinds of waves, a traveling wave and 770 00:38:36,840 --> 00:38:40,799 Speaker 1: a standing wave, what's the difference, Like, do electrons have 771 00:38:40,880 --> 00:38:41,640 Speaker 1: both waves? 772 00:38:41,800 --> 00:38:44,280 Speaker 2: Yeah, the electron field can do both, right. The electron 773 00:38:44,360 --> 00:38:47,000 Speaker 2: field can just oscillate in place in a certain way, 774 00:38:47,280 --> 00:38:50,120 Speaker 2: and that's what a stationary electron is. That's why electrons 775 00:38:50,120 --> 00:38:53,640 Speaker 2: have mass. An electron field can also ripple in a direction. Right, 776 00:38:53,640 --> 00:38:56,520 Speaker 2: that's a traveling wave. Don't think of it as two waves. 777 00:38:56,520 --> 00:38:59,279 Speaker 2: It's the same wave. It's just that electrons you can 778 00:38:59,320 --> 00:39:01,680 Speaker 2: see standing still in which case they're just doing the 779 00:39:01,719 --> 00:39:04,360 Speaker 2: standing wave thing, or you can see them moving, in 780 00:39:04,360 --> 00:39:07,240 Speaker 2: which case it's also a traveling wave, but that depends 781 00:39:07,280 --> 00:39:10,680 Speaker 2: on your frame of reference. Right now, For photons, you 782 00:39:10,800 --> 00:39:13,319 Speaker 2: can't see them standing still because there's no frame of 783 00:39:13,360 --> 00:39:16,440 Speaker 2: reference in which they're at rest. They're always traveling waves. 784 00:39:16,680 --> 00:39:19,240 Speaker 1: When things have a standing wave, are those waves actually 785 00:39:19,400 --> 00:39:21,920 Speaker 1: rippling or are they more like probability waves. 786 00:39:22,040 --> 00:39:24,520 Speaker 2: These are ripples in a field, which some people think 787 00:39:24,600 --> 00:39:27,400 Speaker 2: is a physical thing, right, and so these are should 788 00:39:27,440 --> 00:39:29,160 Speaker 2: and so these should be thought of as like actual 789 00:39:29,200 --> 00:39:33,279 Speaker 2: oscillations in a physical quantity. People think the field is 790 00:39:33,400 --> 00:39:35,600 Speaker 2: real and it's out there. That's sort of a question 791 00:39:35,640 --> 00:39:40,280 Speaker 2: of philosophy. This is separate from like wave functions and probabilities, 792 00:39:40,640 --> 00:39:44,520 Speaker 2: which are in an abstract probability space. These are ripples 793 00:39:44,560 --> 00:39:47,359 Speaker 2: in real space what we think is a real physical thing, 794 00:39:48,000 --> 00:39:50,200 Speaker 2: whether or not it's actually happening, whether you can observe it, 795 00:39:50,239 --> 00:39:52,520 Speaker 2: and what happens when you take measurements, et cetera. There's 796 00:39:52,520 --> 00:39:55,359 Speaker 2: a whole other question in philosophy. But we think these 797 00:39:55,400 --> 00:39:56,920 Speaker 2: are physical ripples of a field. 798 00:39:56,920 --> 00:40:00,680 Speaker 1: It's actually oscillating, and so they're different than the quantum 799 00:40:00,680 --> 00:40:04,160 Speaker 1: probability waves. Right, yes, Okay, Now what does it mean 800 00:40:04,200 --> 00:40:07,560 Speaker 1: that an electron is rippling? In place, like it's jiggling. 801 00:40:07,840 --> 00:40:13,080 Speaker 1: Its energy is increasing and decreasing and pulsating, or what 802 00:40:13,120 --> 00:40:15,880 Speaker 1: does it mean if it's standing still because it's not moving. 803 00:40:15,960 --> 00:40:17,759 Speaker 2: Well, as we talked about with Matt Stresslo, you can 804 00:40:17,800 --> 00:40:19,600 Speaker 2: think about the wave as sort of like the way 805 00:40:19,600 --> 00:40:22,240 Speaker 2: you think about a string oscillating. Right, a guitar string 806 00:40:22,280 --> 00:40:25,400 Speaker 2: can oscillate in place as a standing wave. What's happening 807 00:40:25,440 --> 00:40:28,600 Speaker 2: there is it's oscillating between kinetic and potential energy. Right, 808 00:40:28,600 --> 00:40:30,920 Speaker 2: it gets distorted, it has more potential energy, and then 809 00:40:30,960 --> 00:40:33,400 Speaker 2: it comes back and has kinetic energy, then it slashes 810 00:40:33,440 --> 00:40:36,520 Speaker 2: back into potential energy. So the same way the electron 811 00:40:36,640 --> 00:40:40,080 Speaker 2: field can oscillate between having kinetic and potential energy. So 812 00:40:40,120 --> 00:40:42,800 Speaker 2: the value of the field is changing. It's some values 813 00:40:42,840 --> 00:40:45,239 Speaker 2: that has more potential energy, some values that has less 814 00:40:45,280 --> 00:40:48,480 Speaker 2: potential energy but more kinetic energy, so that energy is 815 00:40:48,520 --> 00:40:51,239 Speaker 2: conserved within the field. It's just oscillating back and forth 816 00:40:51,280 --> 00:40:54,080 Speaker 2: between kinetic and potential energy, the way like a ball 817 00:40:54,320 --> 00:40:57,280 Speaker 2: inside a glass can roll around if you ignore friction, 818 00:40:57,520 --> 00:40:59,920 Speaker 2: it could roll around forever. It's like oscillating within them. 819 00:41:00,560 --> 00:41:03,799 Speaker 1: Or I guess I'm imagining like a balloon sitting in 820 00:41:03,840 --> 00:41:07,919 Speaker 1: space it's maybe squashing and stretching in different directions. Right. 821 00:41:08,280 --> 00:41:11,920 Speaker 1: That means it energy is going between the potential energy 822 00:41:11,960 --> 00:41:16,000 Speaker 1: and kinetic energy as it squeezes and compresses. But then, 823 00:41:16,040 --> 00:41:18,800 Speaker 1: how is that different than traveling waves. 824 00:41:18,960 --> 00:41:21,560 Speaker 2: In order to do this special trick of oscillating in place, 825 00:41:21,880 --> 00:41:24,319 Speaker 2: you have to have mass. Mass is the thing that 826 00:41:24,360 --> 00:41:26,520 Speaker 2: allows you to do that. That's really what mass is 827 00:41:26,960 --> 00:41:30,040 Speaker 2: is the ability to store energy in one location within 828 00:41:30,080 --> 00:41:31,880 Speaker 2: the field. Because remember that mass is just like a 829 00:41:31,920 --> 00:41:36,200 Speaker 2: measurement of internal stored energy. But some fields can't do that, 830 00:41:36,320 --> 00:41:38,959 Speaker 2: Like the photon field doesn't have any mass. There's something 831 00:41:39,000 --> 00:41:41,839 Speaker 2: the electron field can do that the photon field cannot do. 832 00:41:42,360 --> 00:41:44,720 Speaker 2: But the photon field and the electron fields can both 833 00:41:44,800 --> 00:41:48,240 Speaker 2: have traveling waves, which is like a wave moving through space. 834 00:41:48,520 --> 00:41:50,719 Speaker 2: You have an oscillation here, and then the oscillation is 835 00:41:50,719 --> 00:41:53,480 Speaker 2: over there, and the oscillation is further along, So it's 836 00:41:53,480 --> 00:41:55,720 Speaker 2: sort of like that energy is moving through the field 837 00:41:55,960 --> 00:41:57,360 Speaker 2: rather than just staying in place. 838 00:41:57,880 --> 00:41:59,960 Speaker 1: Okay, now, let's say for an electron. Doesn't mean that 839 00:42:00,000 --> 00:42:02,279 Speaker 1: the electron is physically like going up and down as 840 00:42:02,320 --> 00:42:05,720 Speaker 1: it moves or as it's moving in a straight line. 841 00:42:06,160 --> 00:42:09,000 Speaker 1: It's somehow undulating. What exactly is a traveling wave for 842 00:42:09,160 --> 00:42:10,320 Speaker 1: a particle like the electron. 843 00:42:10,760 --> 00:42:12,200 Speaker 2: Yeah, well, it sounds like you're trying to hold in 844 00:42:12,200 --> 00:42:14,600 Speaker 2: your mind simultaneously the picture of an electron is a 845 00:42:14,600 --> 00:42:17,680 Speaker 2: little particle that has a definite location, and you're trying 846 00:42:17,680 --> 00:42:19,239 Speaker 2: to marry that with the idea of a wave. But 847 00:42:19,320 --> 00:42:22,560 Speaker 2: instead just think about the electron as a fluctuation in 848 00:42:22,600 --> 00:42:25,200 Speaker 2: the wave. And as we talked about recently, when you 849 00:42:25,239 --> 00:42:28,200 Speaker 2: think about like how photons ripple, photons are not undulating, 850 00:42:28,200 --> 00:42:31,640 Speaker 2: they're not moving side to side. What's changing along a 851 00:42:31,719 --> 00:42:35,200 Speaker 2: straight line is the value of the field along that line. 852 00:42:35,320 --> 00:42:37,800 Speaker 2: A fields pointing in one direction, and then another direction, 853 00:42:37,840 --> 00:42:40,239 Speaker 2: and then a third direction. Because the photon field is 854 00:42:40,280 --> 00:42:42,960 Speaker 2: actually a vector, it's not just a number, it's a direction. 855 00:42:43,600 --> 00:42:46,480 Speaker 2: So for the electron, again, moving along a straight line, 856 00:42:46,480 --> 00:42:49,320 Speaker 2: as an electron moves, what's changing is the value of 857 00:42:49,360 --> 00:42:52,520 Speaker 2: the electron field along that line. It isn't like wiggle 858 00:42:52,680 --> 00:42:55,440 Speaker 2: sideways in any way, except sometimes when we draw this 859 00:42:55,600 --> 00:42:59,280 Speaker 2: on paper, we draw sideways wiggles to indicate the value 860 00:42:59,280 --> 00:43:03,160 Speaker 2: of the field. In a physical sense, there's no sideways undulation. 861 00:43:03,200 --> 00:43:06,360 Speaker 2: It's just like the numbers of the electron field are changing. 862 00:43:06,800 --> 00:43:09,120 Speaker 2: The electron field is not as complicated as the photon 863 00:43:09,200 --> 00:43:11,960 Speaker 2: field because it's a fermion and not a spin one 864 00:43:11,960 --> 00:43:14,640 Speaker 2: boson like the photon is, which is a full vector. 865 00:43:15,280 --> 00:43:17,400 Speaker 1: Well, just following what you said, which is that you know, 866 00:43:17,719 --> 00:43:20,680 Speaker 1: like an electron has a standing wave like a standing ribble, 867 00:43:21,200 --> 00:43:24,120 Speaker 1: and then it has a traveling wave. But you can 868 00:43:24,120 --> 00:43:26,880 Speaker 1: also imagine a standing wave that's moving in a constant 869 00:43:26,960 --> 00:43:30,080 Speaker 1: speed in a straight line that doesn't need a traveling wave. 870 00:43:30,239 --> 00:43:32,799 Speaker 1: Or is this traveling wave basically a moving standing wave. 871 00:43:33,000 --> 00:43:36,319 Speaker 2: Yeah, that's what a traveling wave is, and it maintains 872 00:43:36,400 --> 00:43:38,880 Speaker 2: its shape, right. One of the cool things about particles 873 00:43:39,160 --> 00:43:42,160 Speaker 2: is as they move through the universe, they maintain their energy. 874 00:43:42,320 --> 00:43:45,399 Speaker 2: They don't like diffuse and spread out, right, because it's 875 00:43:45,400 --> 00:43:48,200 Speaker 2: a minimum oscillation of this quantum field, so it can't 876 00:43:48,239 --> 00:43:50,560 Speaker 2: go down to a lower value. You can't have like 877 00:43:50,800 --> 00:43:53,600 Speaker 2: a half an electron than a quarter electron. So this 878 00:43:53,719 --> 00:43:57,160 Speaker 2: shape maintains itself as it moves through the electron field. 879 00:43:58,520 --> 00:44:00,959 Speaker 1: So then I wonder if maybe the question you're really 880 00:44:01,000 --> 00:44:05,440 Speaker 1: asking here today is whether the standing wave of nutrino 881 00:44:05,760 --> 00:44:08,839 Speaker 1: gets stretched out as the universe expands, like you don't 882 00:44:08,840 --> 00:44:10,480 Speaker 1: even need a natrina to be moving. You can just 883 00:44:10,480 --> 00:44:13,360 Speaker 1: have anatrino standing in space out there. And as the 884 00:44:13,480 --> 00:44:17,080 Speaker 1: universe expands, does the neutrinos standing wave also expand? 885 00:44:17,560 --> 00:44:17,680 Speaker 2: Like? 886 00:44:17,719 --> 00:44:18,920 Speaker 1: Are those do the same question? 887 00:44:19,280 --> 00:44:21,560 Speaker 2: They're not quite the same question, because now you're talking 888 00:44:21,560 --> 00:44:25,120 Speaker 2: about particles at rest, and because the neutrino field and 889 00:44:25,120 --> 00:44:27,920 Speaker 2: the electron field and everything else that has mass has 890 00:44:27,960 --> 00:44:31,000 Speaker 2: a specific frequency at which it can oscillate that isn't 891 00:44:31,040 --> 00:44:35,040 Speaker 2: affected as the universe expands. What is directly affected by 892 00:44:35,080 --> 00:44:37,600 Speaker 2: the expansion of the universe is not the frequency, but 893 00:44:37,640 --> 00:44:41,640 Speaker 2: the wavelength that's always stretched out for all particles. For photons, 894 00:44:41,880 --> 00:44:44,480 Speaker 2: which only have a traveling wave, the wavelength and the 895 00:44:44,560 --> 00:44:49,360 Speaker 2: frequency have a very simple relationship. Longer wavelength, lower frequency. 896 00:44:49,560 --> 00:44:52,640 Speaker 2: For electrons, which also have mass, it works in the 897 00:44:52,680 --> 00:44:56,200 Speaker 2: same direction, but the relationship is more complicated because of 898 00:44:56,239 --> 00:44:59,239 Speaker 2: the mass part. The mass part isn't affected directly by 899 00:44:59,280 --> 00:45:04,279 Speaker 2: the wavelength, but the expansion still influences the overall frequency, 900 00:45:04,520 --> 00:45:07,040 Speaker 2: and that frequency is also affected by the mass part. 901 00:45:07,440 --> 00:45:10,920 Speaker 2: So as the universe expands, it stretches out the wavelength, 902 00:45:11,120 --> 00:45:14,160 Speaker 2: which does in the end lower the electrons frequency. But 903 00:45:14,239 --> 00:45:16,360 Speaker 2: the math is a little bit different. There's a minimum 904 00:45:16,360 --> 00:45:19,600 Speaker 2: frequency for the electrons that they can't lose because they 905 00:45:19,640 --> 00:45:22,880 Speaker 2: still have mass. This effect really only changes how particles 906 00:45:22,920 --> 00:45:25,799 Speaker 2: move through the universe, not how much mass they have. 907 00:45:26,880 --> 00:45:29,120 Speaker 1: All Right, So, then if we're asking the question, do 908 00:45:29,239 --> 00:45:34,000 Speaker 1: neutrinos change wavelengths as the universe expands? What exactly does 909 00:45:34,040 --> 00:45:36,440 Speaker 1: that mean? Does that mean that it's standing wave gets 910 00:45:36,440 --> 00:45:38,759 Speaker 1: stretched or it's traveling wave gets thressed. But then you 911 00:45:38,840 --> 00:45:40,880 Speaker 1: just said that the traveling wave is just as standing 912 00:45:40,920 --> 00:45:43,800 Speaker 1: wave moving in a straight line, So I guess I'm confused. 913 00:45:43,880 --> 00:45:47,520 Speaker 1: What do you mean by a neutrino's wavelength getting stretched 914 00:45:47,680 --> 00:45:48,880 Speaker 1: by this expension. 915 00:45:49,120 --> 00:45:51,759 Speaker 2: There's two different kinds of things that these fields can do, right. 916 00:45:51,840 --> 00:45:54,560 Speaker 2: They can oscillate in place, some of them, and they 917 00:45:54,600 --> 00:45:58,000 Speaker 2: can also oscillate in a traveling wave motion. And so 918 00:45:58,080 --> 00:45:59,359 Speaker 2: for those of you who want to know more about 919 00:45:59,360 --> 00:46:01,520 Speaker 2: the technicality details of that, go back and check out 920 00:46:01,520 --> 00:46:04,040 Speaker 2: our episodes at Matt Strassler about exactly what that means. 921 00:46:04,600 --> 00:46:06,920 Speaker 2: For the purposes of today's episode, we just need to 922 00:46:06,920 --> 00:46:09,760 Speaker 2: think about the motion of those particles, the traveling waves, 923 00:46:10,120 --> 00:46:13,400 Speaker 2: and the frequency of those particles as they're moving, and 924 00:46:13,520 --> 00:46:15,560 Speaker 2: for photons, for example, we know that they get stretched 925 00:46:15,560 --> 00:46:17,600 Speaker 2: out if you see something being emitted from a high 926 00:46:17,640 --> 00:46:20,880 Speaker 2: velocity object, or if the universe is expanding between you 927 00:46:20,920 --> 00:46:23,920 Speaker 2: and them. Really the same effect described in two ways. 928 00:46:24,440 --> 00:46:26,600 Speaker 2: And so the question today is like, does that also 929 00:46:26,640 --> 00:46:29,719 Speaker 2: apply to neutrinos, which we know are generated by stars 930 00:46:29,800 --> 00:46:32,600 Speaker 2: far away and fly to us across space. Does the 931 00:46:32,640 --> 00:46:37,160 Speaker 2: expansion of space also affect them? And the answer is yes, absolutely, 932 00:46:37,640 --> 00:46:40,840 Speaker 2: Their wavelength is also shifted as they move through space 933 00:46:41,440 --> 00:46:44,319 Speaker 2: because everything is just a ripple in these fields, and 934 00:46:44,520 --> 00:46:46,719 Speaker 2: other than the mass ripple, which is controlled by some 935 00:46:46,760 --> 00:46:50,000 Speaker 2: fundamental properties of the field, the velocity of it reflects 936 00:46:50,040 --> 00:46:53,680 Speaker 2: the energy of that particle and that decreases as space expands. 937 00:46:54,719 --> 00:46:57,320 Speaker 1: So what does that mean for a particle like the neutrino? 938 00:46:57,920 --> 00:47:00,160 Speaker 1: Does it? Is it going to look different or is 939 00:47:00,160 --> 00:47:02,800 Speaker 1: going to end up looking or being a different particle 940 00:47:02,840 --> 00:47:04,960 Speaker 1: when it reaches the other side of the universe. 941 00:47:05,120 --> 00:47:07,120 Speaker 2: Yeah, it means that it has less energy, right, It 942 00:47:07,160 --> 00:47:10,359 Speaker 2: doesn't change its fundamental nature. It still has the same mass, 943 00:47:10,400 --> 00:47:12,480 Speaker 2: just like an electron will always have the same mass. 944 00:47:12,560 --> 00:47:14,479 Speaker 2: It still looks the same, It still looks the same, 945 00:47:14,520 --> 00:47:17,120 Speaker 2: but it has less energy. The same way a photon does. Right, 946 00:47:17,160 --> 00:47:19,880 Speaker 2: when a photon gets red shifted, it has less energy 947 00:47:19,920 --> 00:47:24,160 Speaker 2: than it did before. When the universe expands, photons lose energy, 948 00:47:24,400 --> 00:47:27,120 Speaker 2: which is sort of fascinating. Then violets our intuition that 949 00:47:27,160 --> 00:47:30,319 Speaker 2: like energy should be conserved, but it isn't for photons, right, 950 00:47:30,360 --> 00:47:33,400 Speaker 2: photons get lower energy. We have a great example of that, 951 00:47:33,440 --> 00:47:36,480 Speaker 2: which is the cosmic microwave background radiation, which is very 952 00:47:36,560 --> 00:47:39,279 Speaker 2: very red. Photons they're down in the microwave, but when 953 00:47:39,280 --> 00:47:41,560 Speaker 2: they were emitted back in the very early universe, they 954 00:47:41,600 --> 00:47:43,960 Speaker 2: were very high energy because they were emitted from a 955 00:47:43,960 --> 00:47:47,800 Speaker 2: super duper hot, bright gas. And as the universe has expanded, 956 00:47:48,000 --> 00:47:51,160 Speaker 2: they've been stretched out to very low energies. So the 957 00:47:51,160 --> 00:47:54,399 Speaker 2: same thing happens to neutrinos and electrons and every other 958 00:47:54,440 --> 00:47:58,600 Speaker 2: particle moving through the universe as the universe expands. Or equivalently, again, 959 00:47:58,600 --> 00:48:01,239 Speaker 2: if you emitted from something moving at high speed away 960 00:48:01,239 --> 00:48:05,120 Speaker 2: from you, and those particles are red shifted to lower energy, 961 00:48:05,280 --> 00:48:07,320 Speaker 2: same mass, but lower kinetic energy. 962 00:48:07,440 --> 00:48:09,600 Speaker 1: So wait, wait, are you just basically saying that the 963 00:48:09,640 --> 00:48:12,920 Speaker 1: expansion of the universe slows down neutrinos. 964 00:48:13,160 --> 00:48:15,479 Speaker 2: Yes, absolutely it does, and it's a really interesting point, 965 00:48:15,560 --> 00:48:19,080 Speaker 2: because photons don't get slower, right, They just get lower 966 00:48:19,160 --> 00:48:22,239 Speaker 2: energy at the same velocity, because photons are always moving 967 00:48:22,239 --> 00:48:24,640 Speaker 2: at the speed of light. But neutrinos have mass, and 968 00:48:24,680 --> 00:48:27,240 Speaker 2: so as they get lower energy, they do get slower. 969 00:48:27,600 --> 00:48:30,160 Speaker 2: They're basically always traveling at almost the speed of light 970 00:48:30,200 --> 00:48:33,760 Speaker 2: anyway because their mass is so small. But yes, technically 971 00:48:33,840 --> 00:48:36,400 Speaker 2: they do get slower as their wavelength gets longer. 972 00:48:36,640 --> 00:48:40,600 Speaker 1: Right, right, So then what's the difference between neutrino that 973 00:48:40,680 --> 00:48:43,239 Speaker 1: I detegged from the Sun which is really close to us, 974 00:48:43,480 --> 00:48:45,600 Speaker 1: and in neutrina that is emitted by the Sun really 975 00:48:45,600 --> 00:48:48,600 Speaker 1: far away that gets to us after billions of years 976 00:48:48,600 --> 00:48:52,280 Speaker 1: and it's been going through expanding space when it gets 977 00:48:52,320 --> 00:48:55,839 Speaker 1: to me and I compare to the nutrina from our sun. 978 00:48:56,280 --> 00:48:57,840 Speaker 1: Do they look the same? It's just that one of 979 00:48:57,880 --> 00:49:00,279 Speaker 1: them is going faster than the other. Or are they 980 00:49:00,320 --> 00:49:01,200 Speaker 1: going to look different? 981 00:49:01,480 --> 00:49:04,360 Speaker 2: Well, each individual neutrino will not look different, but the 982 00:49:04,400 --> 00:49:07,120 Speaker 2: spectrum of them will. So if you measure the energy 983 00:49:07,160 --> 00:49:09,279 Speaker 2: of all the neutrinos from the Sun you make a 984 00:49:09,280 --> 00:49:11,640 Speaker 2: graph of that, it's going to have some distribution. And 985 00:49:11,640 --> 00:49:15,000 Speaker 2: then if you measure the energies of neutrinos from distant stars, 986 00:49:15,120 --> 00:49:16,840 Speaker 2: stars that are really far away from us, where the 987 00:49:16,920 --> 00:49:19,719 Speaker 2: universes expanded between us and them, those will have a 988 00:49:19,760 --> 00:49:23,680 Speaker 2: lower energy distribution, exactly the same way is for photons. 989 00:49:24,000 --> 00:49:27,280 Speaker 2: Photons from distant stars are shifted down lower in energy. 990 00:49:27,560 --> 00:49:30,560 Speaker 2: Neutrino energy distribution should also be shifted down. 991 00:49:30,960 --> 00:49:32,600 Speaker 1: Shoot, so they'll just be slower. 992 00:49:33,960 --> 00:49:34,280 Speaker 2: Yeah. 993 00:49:34,320 --> 00:49:37,000 Speaker 1: So I mean basically you can ask this question of anything. 994 00:49:37,120 --> 00:49:38,920 Speaker 1: Any particle doesn't have to be neutrinos. 995 00:49:39,000 --> 00:49:39,200 Speaker 2: Yeah. 996 00:49:39,560 --> 00:49:42,680 Speaker 1: So, like an electron that is shot at us from 997 00:49:42,719 --> 00:49:44,960 Speaker 1: really far away, by the time it gets us, it's 998 00:49:45,000 --> 00:49:47,040 Speaker 1: going to be going at a slower speed. 999 00:49:47,480 --> 00:49:50,080 Speaker 2: Yeah, or as we say, colder or redder. But yeah, 1000 00:49:50,080 --> 00:49:51,800 Speaker 2: fundamentally it's a lower velocity. 1001 00:49:52,000 --> 00:49:55,200 Speaker 1: Right. I mean you can say smeliar too, but I 1002 00:49:55,280 --> 00:49:58,840 Speaker 1: think the practical says you would just say it's slower. 1003 00:49:59,000 --> 00:50:01,960 Speaker 2: Yeah, it's definitely slower as less kinetic energy. 1004 00:50:02,400 --> 00:50:05,160 Speaker 1: Ah. Wait, so that means like if I was Superman, 1005 00:50:05,760 --> 00:50:08,680 Speaker 1: or if I was shot out of a cannon from 1006 00:50:08,680 --> 00:50:11,960 Speaker 1: a space station in orbit around Earth and I was 1007 00:50:12,239 --> 00:50:16,360 Speaker 1: flying through space, nothing gets in my way, no dust, nothing, 1008 00:50:16,719 --> 00:50:19,400 Speaker 1: I would still slow down eventually to a standstill. 1009 00:50:19,560 --> 00:50:21,680 Speaker 2: Depends on what you mean by standstill, because there's no 1010 00:50:21,719 --> 00:50:25,480 Speaker 2: absolute velocity in space, right, And I think that this 1011 00:50:25,560 --> 00:50:27,600 Speaker 2: slow down is a relative effect, so you would as 1012 00:50:27,600 --> 00:50:32,640 Speaker 2: symptotically approach zero velocity relative to some observer. But yes, 1013 00:50:32,719 --> 00:50:35,200 Speaker 2: things do get slowed down as the universe expands. 1014 00:50:35,480 --> 00:50:38,279 Speaker 1: Yeah, Like initially I would see planets whizzing by me, 1015 00:50:39,400 --> 00:50:42,200 Speaker 1: but then eventually at the end of the universe, planets 1016 00:50:42,239 --> 00:50:43,879 Speaker 1: would not be whizzing by me. That would be going 1017 00:50:44,080 --> 00:50:45,279 Speaker 1: slower relative to them. 1018 00:50:45,760 --> 00:50:48,399 Speaker 2: Yeah, I remember that this is a relative effect, right. 1019 00:50:48,560 --> 00:50:50,960 Speaker 2: One person will see a photon red shifted, somebody else 1020 00:50:50,960 --> 00:50:54,000 Speaker 2: see that same photon not red shifted. So this is 1021 00:50:54,040 --> 00:50:56,279 Speaker 2: a frame dependent effect. 1022 00:50:56,040 --> 00:50:59,400 Speaker 1: Right, But it's basically as I just describe. But initially 1023 00:50:59,400 --> 00:51:02,480 Speaker 1: things will whizzing by me, but eventually the things will 1024 00:51:02,520 --> 00:51:03,400 Speaker 1: be going by me slower. 1025 00:51:03,480 --> 00:51:05,600 Speaker 2: I'm not one hundred percent sure about the thrust of 1026 00:51:05,680 --> 00:51:08,640 Speaker 2: Superman here, but if he only has an initial velocity 1027 00:51:08,640 --> 00:51:09,920 Speaker 2: and that he's coasting. 1028 00:51:09,840 --> 00:51:11,920 Speaker 1: Forget I said, Superman. That's why I shipped it to 1029 00:51:12,040 --> 00:51:14,640 Speaker 1: a cannon, Like if I get shot out of a cannon. Now, 1030 00:51:14,680 --> 00:51:17,440 Speaker 1: does that mean that our whole episode here today? Instead 1031 00:51:17,440 --> 00:51:20,040 Speaker 1: of calling it can Neutrina's be red shifted if they 1032 00:51:20,200 --> 00:51:22,640 Speaker 1: we could have just called it. Do things in space 1033 00:51:22,680 --> 00:51:24,680 Speaker 1: get slowed down by the expansion of the universe? 1034 00:51:25,080 --> 00:51:29,160 Speaker 2: And the answer is yes, except for photons. Photons get 1035 00:51:29,239 --> 00:51:31,799 Speaker 2: red shifted, but they don't get slowed down because they 1036 00:51:31,840 --> 00:51:35,160 Speaker 2: have no mass. They're always traveling at the speed of light, right. 1037 00:51:35,000 --> 00:51:38,160 Speaker 1: But the light is not a thing. Basically, does anything 1038 00:51:38,200 --> 00:51:42,680 Speaker 1: with mass things matter gets slowed down as the universe expands, 1039 00:51:42,719 --> 00:51:44,320 Speaker 1: and it seems like answers yes. 1040 00:51:44,160 --> 00:51:46,680 Speaker 2: The answer is yes, but it's very difficult to see 1041 00:51:46,719 --> 00:51:49,040 Speaker 2: because in order to detect that, to do the experiment 1042 00:51:49,080 --> 00:51:51,960 Speaker 2: I mentioned, you'd need to have a source of neutrinos 1043 00:51:52,000 --> 00:51:54,800 Speaker 2: with very specific energies. And because we see so few 1044 00:51:54,920 --> 00:51:58,200 Speaker 2: neutrinos it's so difficult to pin them down to observe them. 1045 00:51:58,560 --> 00:52:01,000 Speaker 2: We can't actually do the experiment that I talked about earlier, 1046 00:52:01,080 --> 00:52:04,200 Speaker 2: like looking at the distribution of energies of neutrinos from 1047 00:52:04,200 --> 00:52:07,920 Speaker 2: a distant star. And also stars don't emit neutrinos a 1048 00:52:08,080 --> 00:52:11,880 Speaker 2: very specific energies the way they do photons, right, and 1049 00:52:11,920 --> 00:52:14,799 Speaker 2: so we don't have like spectral lines of neutrinos that 1050 00:52:14,840 --> 00:52:18,120 Speaker 2: we can use to measure these redshifts. But the only 1051 00:52:18,160 --> 00:52:21,560 Speaker 2: thing we can do is look for the cosmic neutrino background, 1052 00:52:21,600 --> 00:52:24,680 Speaker 2: which is similar to the cosmic microwave background. We think 1053 00:52:24,719 --> 00:52:27,080 Speaker 2: there were a bunch of neutrinos created in the early universe, 1054 00:52:27,200 --> 00:52:30,200 Speaker 2: very high speed, very high energy, and the expansion of 1055 00:52:30,239 --> 00:52:33,799 Speaker 2: space has cooled them all down to much slower moving neutrinos, 1056 00:52:33,960 --> 00:52:36,760 Speaker 2: still nearly the speed of light, but much slower moving. 1057 00:52:36,960 --> 00:52:40,520 Speaker 2: If we can measure the cosmic neutrino background and basically 1058 00:52:40,600 --> 00:52:44,160 Speaker 2: measure their velocity their energy distribution, that would be direct 1059 00:52:44,200 --> 00:52:47,080 Speaker 2: evidence of seeing particles slowed down by the expansion of 1060 00:52:47,120 --> 00:52:50,399 Speaker 2: the universe, or red shifted neutrinos. But we haven't seen 1061 00:52:50,440 --> 00:52:50,879 Speaker 2: them yet. 1062 00:52:51,080 --> 00:52:53,279 Speaker 1: But I wonder if there's maybe an easier experiment you 1063 00:52:53,280 --> 00:52:55,359 Speaker 1: can do. Can you look at other particles that are 1064 00:52:55,360 --> 00:52:57,680 Speaker 1: getting to us from far away. Can we just tell 1065 00:52:57,719 --> 00:53:00,640 Speaker 1: that they're somehow slower than the particles that are being 1066 00:53:00,880 --> 00:53:03,920 Speaker 1: sent to us from closer sources, or is there no 1067 00:53:04,000 --> 00:53:04,439 Speaker 1: such thing. 1068 00:53:04,880 --> 00:53:07,680 Speaker 2: It's difficult because we're talking about particles, and particles don't 1069 00:53:07,719 --> 00:53:09,920 Speaker 2: make it through the universe the same way photons do, 1070 00:53:10,480 --> 00:53:14,040 Speaker 2: so it's harder to attribute individual particles to like specific 1071 00:53:14,120 --> 00:53:17,880 Speaker 2: extragalactic sources and we're talking about like electrons or protons 1072 00:53:17,920 --> 00:53:21,400 Speaker 2: from another galaxy with a very small number of those. 1073 00:53:21,800 --> 00:53:24,120 Speaker 2: Those are very high energy cosmic rays, and we have 1074 00:53:24,239 --> 00:53:27,000 Speaker 2: lots of questions about what's even making those. So no, 1075 00:53:27,120 --> 00:53:30,120 Speaker 2: we don't have a good sample of electrons or protons 1076 00:53:30,120 --> 00:53:31,799 Speaker 2: from other galaxies to do that kind of. 1077 00:53:31,719 --> 00:53:33,840 Speaker 1: Experiment with, or would you even need to do the 1078 00:53:33,880 --> 00:53:37,319 Speaker 1: experiment just because that's what relativity says it's going to happen. Right, 1079 00:53:37,400 --> 00:53:38,960 Speaker 1: things are going to slow down as you move through 1080 00:53:38,960 --> 00:53:42,400 Speaker 1: expanding space, and we already know that a lot of 1081 00:53:42,800 --> 00:53:45,839 Speaker 1: relativity is true, So why wouldn't it work for this case. 1082 00:53:45,960 --> 00:53:48,120 Speaker 2: Yeah, we have no reason to think it wouldn't, but 1083 00:53:48,200 --> 00:53:50,520 Speaker 2: it's always a good idea to double check because there 1084 00:53:50,520 --> 00:53:52,680 Speaker 2: could be a surprise. It could be one of those 1085 00:53:52,680 --> 00:53:54,800 Speaker 2: things where we're like, yeah, that's totally going to be boring, 1086 00:53:55,400 --> 00:53:57,720 Speaker 2: go out and do it, yon yon yon, Oh my gosh, 1087 00:53:57,719 --> 00:54:01,040 Speaker 2: what and the universe tells us something new. So we 1088 00:54:01,080 --> 00:54:03,840 Speaker 2: strongly suspect and believe that this is what's happening. But 1089 00:54:03,920 --> 00:54:05,200 Speaker 2: you always got to check the stuff. 1090 00:54:05,440 --> 00:54:07,040 Speaker 1: Right, Right, you're saying it's a good idea to shoot 1091 00:54:07,080 --> 00:54:08,800 Speaker 1: Joorge out of a cannon, space. 1092 00:54:10,520 --> 00:54:12,520 Speaker 2: Good idea aboutity? I don't know, but we could learn 1093 00:54:12,560 --> 00:54:12,839 Speaker 2: a lot. 1094 00:54:13,200 --> 00:54:15,680 Speaker 1: Yeah, yeah, although it would be hard because you know, 1095 00:54:15,719 --> 00:54:19,040 Speaker 1: to make it a perfect experiment. As I'm flying through space, 1096 00:54:19,120 --> 00:54:23,400 Speaker 1: I can't eject any matter because it would ruin the experiment. 1097 00:54:23,480 --> 00:54:24,719 Speaker 2: Right, mm hmmm yeah. 1098 00:54:24,760 --> 00:54:30,920 Speaker 1: So if you I see where you're going with just 1099 00:54:30,960 --> 00:54:34,160 Speaker 1: trying to bring it back around or down, as the 1100 00:54:34,239 --> 00:54:37,960 Speaker 1: case may be. So if we do an experiment, uh no, 1101 00:54:38,239 --> 00:54:39,880 Speaker 1: the person can fart fart right. 1102 00:54:40,360 --> 00:54:42,880 Speaker 2: That's right. You got to hold it in, hold it in. 1103 00:54:43,040 --> 00:54:45,000 Speaker 1: Hold it in, hold it in for billions of years, 1104 00:54:45,040 --> 00:54:50,400 Speaker 1: hold it in for I think I feel like like 1105 00:54:50,440 --> 00:54:54,960 Speaker 1: that just describes my job here in the podcast, holding 1106 00:54:55,000 --> 00:54:56,960 Speaker 1: it in or not hold it in, hold it in. 1107 00:54:58,239 --> 00:54:59,720 Speaker 1: I don't think you've been holding it together. 1108 00:55:00,000 --> 00:55:03,600 Speaker 2: You've been letting it all out on this episode. 1109 00:55:04,520 --> 00:55:08,399 Speaker 1: Are you saying I've been I've been stinking it up? 1110 00:55:08,760 --> 00:55:12,919 Speaker 1: What you're saying with far jokes, you're like you said 1111 00:55:12,920 --> 00:55:16,560 Speaker 1: it or on me? All right? Well, I guess just 1112 00:55:16,560 --> 00:55:20,279 Speaker 1: to recap the question, we started asking, can Neutrino's get 1113 00:55:20,320 --> 00:55:23,240 Speaker 1: red shifted right off the gate? The answers no, because 1114 00:55:23,760 --> 00:55:26,560 Speaker 1: I think most people would agree redshifting only applies to 1115 00:55:27,280 --> 00:55:30,080 Speaker 1: electromagnetic light, as some of our listeners pointed out. 1116 00:55:30,080 --> 00:55:33,320 Speaker 2: Where most people notably doesn't include me. But yes, go ahead, Oh. 1117 00:55:33,120 --> 00:55:37,560 Speaker 1: That's why it's most But if you have a question, 1118 00:55:37,840 --> 00:55:40,760 Speaker 1: the wavelength of the neutrino get stretched out by explaining universe, 1119 00:55:40,840 --> 00:55:43,319 Speaker 1: and the answers yes, in fact, it happens to all 1120 00:55:43,360 --> 00:55:47,600 Speaker 1: particles with mass, right, And really what that means doesn't 1121 00:55:47,640 --> 00:55:49,879 Speaker 1: mean that it somehow changes the neutrina It just means 1122 00:55:49,920 --> 00:55:50,719 Speaker 1: that it slows down. 1123 00:55:50,920 --> 00:55:51,160 Speaker 2: Yeah. 1124 00:55:51,239 --> 00:55:55,480 Speaker 1: So really the question is do particles get slowed down 1125 00:55:55,520 --> 00:55:58,000 Speaker 1: by the expansion of the universe, And you're saying the 1126 00:55:58,040 --> 00:56:00,640 Speaker 1: answers yes, because that's what relativity tells us. 1127 00:56:00,920 --> 00:56:04,640 Speaker 2: Yeah, all particles have their wavelength extended when the universe expands. 1128 00:56:04,640 --> 00:56:06,880 Speaker 2: For photons, that doesn't mean a change in the velocity, 1129 00:56:06,920 --> 00:56:08,479 Speaker 2: but for particles with mass it does. 1130 00:56:08,920 --> 00:56:13,279 Speaker 1: All right, Well, it was a circuitous path, but we 1131 00:56:13,360 --> 00:56:15,480 Speaker 1: got here. Now, what happens to a fart with the 1132 00:56:15,520 --> 00:56:20,240 Speaker 1: expansion of the universe. It also slows down, right. 1133 00:56:20,080 --> 00:56:22,520 Speaker 2: It slows down, But the stink is invariant like mass. 1134 00:56:22,560 --> 00:56:25,200 Speaker 2: It's a fundamental quality of the fart. Something the fart 1135 00:56:25,200 --> 00:56:25,919 Speaker 2: field can do. 1136 00:56:25,920 --> 00:56:30,000 Speaker 1: Each individual particle. Its stinkiness does not decrease because its 1137 00:56:30,080 --> 00:56:30,919 Speaker 1: nature doesn't change. 1138 00:56:31,239 --> 00:56:33,560 Speaker 2: I prefer to think about farts it's waves as they 1139 00:56:33,560 --> 00:56:35,520 Speaker 2: sort of pass over you, rather than think about the 1140 00:56:35,520 --> 00:56:37,360 Speaker 2: individual fart particles than where they came. 1141 00:56:37,239 --> 00:56:41,480 Speaker 1: From sticking in your nose. Yeah, nobody wants to think 1142 00:56:41,480 --> 00:56:45,640 Speaker 1: about that exactly. Yeah, all right, well, I think another 1143 00:56:45,760 --> 00:56:49,600 Speaker 1: lesson about how crazy this universe is and how big 1144 00:56:49,640 --> 00:56:52,920 Speaker 1: it is, and how the effects of it getting even bigger. 1145 00:56:53,200 --> 00:56:54,839 Speaker 1: What's that going to do to everything in it? 1146 00:56:55,000 --> 00:56:57,600 Speaker 2: That's right, And our intuition for what happens to photons 1147 00:56:57,600 --> 00:57:01,000 Speaker 2: sometimes does apply to other particles. Because they have mass, 1148 00:57:01,000 --> 00:57:02,920 Speaker 2: they follow slightly different rules. 1149 00:57:03,280 --> 00:57:06,120 Speaker 1: All right, We hope you enjoyed that. Thanks for joining us. 1150 00:57:06,880 --> 00:57:07,720 Speaker 1: See you next time. 1151 00:57:12,640 --> 00:57:15,799 Speaker 2: For more science and curiosity, come find us on social media, 1152 00:57:15,920 --> 00:57:20,440 Speaker 2: where we answer questions and post videos. We're on Twitter, This, Org, Insta, 1153 00:57:20,560 --> 00:57:24,280 Speaker 2: and now TikTok. Thanks for listening, and remember that Daniel 1154 00:57:24,280 --> 00:57:27,760 Speaker 2: and Jorge Explain the Universe is a production of iHeartRadio. 1155 00:57:28,000 --> 00:57:33,200 Speaker 2: For more podcasts from iHeartRadio, visit the iHeartRadio Apple Apple Podcasts, 1156 00:57:33,280 --> 00:57:35,640 Speaker 2: or wherever you listen to your favorite shows.