1 00:00:09,080 --> 00:00:12,160 Speaker 1: Or Hey, what's your favorite number? Well, I like all numbers. 2 00:00:12,160 --> 00:00:14,400 Speaker 1: I try not to discriminate between numbers, but you know, 3 00:00:14,440 --> 00:00:16,400 Speaker 1: I think since I was little, I've always liked the 4 00:00:16,480 --> 00:00:19,680 Speaker 1: number four. Number four. Why is that that's a lot 5 00:00:19,800 --> 00:00:23,400 Speaker 1: less than the number of bananas in a bunch for example? Well, 6 00:00:23,520 --> 00:00:25,360 Speaker 1: I think I liked it because when I was literally 7 00:00:25,440 --> 00:00:27,639 Speaker 1: kind of blew my mind that, you know, four was 8 00:00:27,760 --> 00:00:30,440 Speaker 1: two plus two and it was two times two, and 9 00:00:30,480 --> 00:00:32,600 Speaker 1: it was two to the two, and so I just 10 00:00:32,600 --> 00:00:35,080 Speaker 1: thought that was like amazing, Right, it's pretty two two. 11 00:00:35,320 --> 00:00:37,600 Speaker 1: What about you, what is your favorite number? Oh, that's easy. 12 00:00:37,680 --> 00:00:41,040 Speaker 1: It's got to be forty two, because forty two. It's 13 00:00:41,040 --> 00:00:43,680 Speaker 1: the answer to everything. So maybe that should be our 14 00:00:43,680 --> 00:00:47,120 Speaker 1: podcast title. Forty two explains the universe forget about those 15 00:00:47,159 --> 00:00:49,920 Speaker 1: two guys. I guess we could stretch that to forty 16 00:00:49,920 --> 00:00:52,600 Speaker 1: five minutes, right, The answered everything is just forty two. 17 00:00:52,840 --> 00:00:57,680 Speaker 1: Every episode would be forty two minutes long, and we'd 18 00:00:57,680 --> 00:01:00,760 Speaker 1: have forty two good jokes. They would cancel it after 19 00:01:00,800 --> 00:01:05,160 Speaker 1: forty two episodes, and I hope we have forty two 20 00:01:05,520 --> 00:01:21,959 Speaker 1: million listeners. Hi am more hand made cartoonists and the 21 00:01:22,000 --> 00:01:25,560 Speaker 1: creator of PhD comments, Hi, I'm Daniel Whitzen. I'm a 22 00:01:25,600 --> 00:01:28,520 Speaker 1: particle physicist, and I'm a co author of our book 23 00:01:28,680 --> 00:01:32,080 Speaker 1: We Have No Idea, a Guide to the Unknown Universe, 24 00:01:32,120 --> 00:01:35,360 Speaker 1: and which we talk about all the amazing open mysteries 25 00:01:35,360 --> 00:01:38,000 Speaker 1: of the universe, all the things science has figured out, 26 00:01:38,160 --> 00:01:41,120 Speaker 1: and all the things science has not figured out. It's right, 27 00:01:41,120 --> 00:01:42,520 Speaker 1: there are a lot of books out there about all 28 00:01:42,560 --> 00:01:44,440 Speaker 1: the things we know about the universe, but ours is 29 00:01:44,520 --> 00:01:47,280 Speaker 1: about all the things we don't know. And believe it 30 00:01:47,319 --> 00:01:49,920 Speaker 1: or not, we filled the whole book with things we 31 00:01:50,000 --> 00:01:52,160 Speaker 1: don't know. And it's not just what Jorge and I 32 00:01:52,200 --> 00:01:54,480 Speaker 1: don't know about the universe, which is a lot, but 33 00:01:54,520 --> 00:01:56,840 Speaker 1: it's about what science in general. We try to speak 34 00:01:56,880 --> 00:02:00,000 Speaker 1: for humanity and bring you to the forefront of human knowledge, 35 00:02:00,360 --> 00:02:03,440 Speaker 1: to delve into the deepest questions about the biggest things 36 00:02:03,440 --> 00:02:06,680 Speaker 1: in the universe, i e. The entire universe, Because it 37 00:02:06,720 --> 00:02:09,040 Speaker 1: turns out there's a lot that scientists don't know about 38 00:02:09,440 --> 00:02:13,480 Speaker 1: this great, big and complex and beautiful universe, including sometimes 39 00:02:13,520 --> 00:02:16,400 Speaker 1: things about numbers. Yeah, because one way to tear the 40 00:02:16,480 --> 00:02:20,359 Speaker 1: universe apart is to sort of take it apart literally physically, 41 00:02:20,440 --> 00:02:22,960 Speaker 1: and say I am made of bits. What are those 42 00:02:23,000 --> 00:02:25,400 Speaker 1: bits made out of what are those bits made out of? 43 00:02:25,600 --> 00:02:27,440 Speaker 1: And then you can drill down to the sort of 44 00:02:27,480 --> 00:02:31,280 Speaker 1: the the core bit, the fundamental element of the universe. 45 00:02:31,600 --> 00:02:33,960 Speaker 1: But there's another way to look at the universe, another 46 00:02:33,960 --> 00:02:36,600 Speaker 1: way to think about it, and that's more mathematical, to 47 00:02:36,639 --> 00:02:40,120 Speaker 1: think about what are the basic numbers? Like if you 48 00:02:40,240 --> 00:02:43,640 Speaker 1: had a theory of the universe, what numbers would appear 49 00:02:43,680 --> 00:02:45,560 Speaker 1: in it? Yeah, Like if you had an equation that 50 00:02:45,639 --> 00:02:49,160 Speaker 1: just describes everything in the universe, would it have any 51 00:02:49,280 --> 00:02:52,840 Speaker 1: numbers in it or not? Or just symbols or concepts? 52 00:02:52,880 --> 00:02:55,919 Speaker 1: And what would those numbers be, right? And why would 53 00:02:55,960 --> 00:02:58,720 Speaker 1: they be those numbers and not other numbers? I like 54 00:02:58,800 --> 00:03:01,440 Speaker 1: to think about some he's sitting at a control panel 55 00:03:01,480 --> 00:03:03,840 Speaker 1: for the universe. Maybe the universe is a simulation and 56 00:03:03,880 --> 00:03:06,440 Speaker 1: somebody up there has knobs and they're twiddling it. And 57 00:03:06,560 --> 00:03:09,720 Speaker 1: you know, as you change those knobs, the universe looks different. 58 00:03:09,880 --> 00:03:12,840 Speaker 1: And so our job is to measure the value of 59 00:03:12,840 --> 00:03:15,320 Speaker 1: those knobs and then to ask, like why this value 60 00:03:15,440 --> 00:03:17,680 Speaker 1: not something else could have been anything? Are these two 61 00:03:17,720 --> 00:03:21,000 Speaker 1: knobs actually connected? Is there just one big knob? Yeah? 62 00:03:21,040 --> 00:03:24,280 Speaker 1: Like why are our podcast always about forty five minutes? 63 00:03:24,440 --> 00:03:26,639 Speaker 1: Is there a universe in which our podcasts are shorter 64 00:03:26,919 --> 00:03:30,359 Speaker 1: or longer. That's as long as we can be funny. 65 00:03:30,360 --> 00:03:34,200 Speaker 1: For after that it just trails off. Yeah. In fact, 66 00:03:34,240 --> 00:03:36,480 Speaker 1: even the number of knobs that the universe might have 67 00:03:36,760 --> 00:03:39,840 Speaker 1: would be significant, Like if the universe had seven knobs 68 00:03:39,960 --> 00:03:42,839 Speaker 1: versus three knobs, that would be pretty significant and would 69 00:03:42,880 --> 00:03:46,480 Speaker 1: tell you a lot about whoever or whatever made this universe. Yeah, 70 00:03:46,520 --> 00:03:48,960 Speaker 1: and this is a deep question, not just of science, 71 00:03:49,000 --> 00:03:51,880 Speaker 1: but also of philosophy. If you think the goal of 72 00:03:51,920 --> 00:03:54,640 Speaker 1: science is to reveal the truth about the universe, then 73 00:03:54,680 --> 00:03:57,120 Speaker 1: you have to be prepared to answer the question what 74 00:03:57,240 --> 00:04:00,360 Speaker 1: does that truth mean or does it inform us? Right? 75 00:04:00,480 --> 00:04:02,320 Speaker 1: If you're going to ask a question, you better know 76 00:04:02,360 --> 00:04:04,120 Speaker 1: how to interpret the answer, which is of course the 77 00:04:04,160 --> 00:04:07,080 Speaker 1: underlying joke behind forty two. Those folks that build a 78 00:04:07,160 --> 00:04:09,800 Speaker 1: huge planet sized computer to figure out the answer to life, 79 00:04:09,840 --> 00:04:12,480 Speaker 1: the universe and everything and then have no idea what 80 00:04:12,600 --> 00:04:14,480 Speaker 1: it means. You think they know there's a universe out 81 00:04:14,480 --> 00:04:17,680 Speaker 1: there in which there Douglas Adam wrote the same book 82 00:04:17,720 --> 00:04:22,720 Speaker 1: but used the number forty one, or and there are 83 00:04:22,800 --> 00:04:25,479 Speaker 1: jokes are all about that number. I don't know. I'd 84 00:04:25,480 --> 00:04:27,200 Speaker 1: love to read an interview with him about how he 85 00:04:27,279 --> 00:04:31,120 Speaker 1: chose that number, because it's achieved such cultural prominence. You know, 86 00:04:31,200 --> 00:04:33,560 Speaker 1: they did a survey of like all the numbers that 87 00:04:33,640 --> 00:04:38,480 Speaker 1: appear in Python code on GitHub, and they plotted the distribution, 88 00:04:38,520 --> 00:04:40,720 Speaker 1: and there's a big spike at forty two. People just 89 00:04:40,760 --> 00:04:42,960 Speaker 1: like use it as an arbitrary number all the time. 90 00:04:44,120 --> 00:04:47,760 Speaker 1: Maybe it's not a coincidence, or you know, maybe it 91 00:04:47,880 --> 00:04:50,040 Speaker 1: is a basic number that just pops up. It's the 92 00:04:50,120 --> 00:04:54,080 Speaker 1: number of neurons that work in an average person's head. Maybe. Yeah, 93 00:04:54,080 --> 00:04:56,520 Speaker 1: So this is an interesting concept to think about the 94 00:04:56,520 --> 00:04:58,720 Speaker 1: constants of the universe. And so today on the episode, 95 00:04:58,720 --> 00:05:06,760 Speaker 1: we'll be asking the question what are the basic constants 96 00:05:06,760 --> 00:05:10,120 Speaker 1: of the universe? And are they even constants? And why 97 00:05:10,160 --> 00:05:12,920 Speaker 1: do physicists keep calling things constant when they don't know 98 00:05:12,960 --> 00:05:15,120 Speaker 1: if they are. Why can't they be consistent about it 99 00:05:15,760 --> 00:05:19,400 Speaker 1: or at least conscientious, Right, It seems like a constant 100 00:05:19,400 --> 00:05:23,240 Speaker 1: annoyance to have to recalibrate my meaning of words when 101 00:05:23,279 --> 00:05:25,240 Speaker 1: I talk to physicists. Yeah, and I don't think it's 102 00:05:25,240 --> 00:05:28,159 Speaker 1: even a conscious thing. You know, we talk about constants, 103 00:05:28,160 --> 00:05:30,279 Speaker 1: we really mean numbers. But then there's a question, you know, 104 00:05:30,400 --> 00:05:33,680 Speaker 1: are these numbers actually constant. Are they changing? How could 105 00:05:33,760 --> 00:05:35,599 Speaker 1: we tell if they were changing? What if two of 106 00:05:35,600 --> 00:05:38,080 Speaker 1: them are changing at the same time, would we even notice? 107 00:05:38,400 --> 00:05:41,040 Speaker 1: These are really fun, interesting questions, and they really go 108 00:05:41,200 --> 00:05:43,760 Speaker 1: deep into the nature of the universe itself. You know, 109 00:05:43,839 --> 00:05:46,800 Speaker 1: we have these basic laws that describe sort of how 110 00:05:46,839 --> 00:05:49,520 Speaker 1: things interact. But then they're just seemed to be numbers 111 00:05:49,560 --> 00:05:52,160 Speaker 1: that determine, you know, the relative power, like why is 112 00:05:52,200 --> 00:05:55,360 Speaker 1: the gravitational force so much weaker than the other forces? 113 00:05:55,839 --> 00:05:59,080 Speaker 1: You know, why our stars so far apart. There's has 114 00:05:59,120 --> 00:06:01,440 Speaker 1: to be something to say at these scales to determine 115 00:06:01,600 --> 00:06:04,680 Speaker 1: why the universe turned out this way and not other ways. Daniel, 116 00:06:04,720 --> 00:06:07,240 Speaker 1: I feel like this baby. This question assumes that there 117 00:06:07,279 --> 00:06:09,520 Speaker 1: are basic constants in the universe. Do we know for 118 00:06:09,600 --> 00:06:11,520 Speaker 1: sure that there are constants in the universe? Is it 119 00:06:11,600 --> 00:06:15,440 Speaker 1: may be just something that we haven't discovered or something Well, 120 00:06:15,480 --> 00:06:18,440 Speaker 1: we have constants that we've measured and we do not 121 00:06:18,600 --> 00:06:20,760 Speaker 1: know how to derive them, and we'll get into the 122 00:06:20,760 --> 00:06:22,880 Speaker 1: definition of what it means to be a basic constant. 123 00:06:23,320 --> 00:06:26,280 Speaker 1: Um there used to be more right, and sometimes we discover, oh, 124 00:06:26,279 --> 00:06:28,960 Speaker 1: this thing that we thought was fundamental turns out to 125 00:06:29,000 --> 00:06:31,039 Speaker 1: just be a combination of these other numbers, and so 126 00:06:31,120 --> 00:06:33,360 Speaker 1: we don't need it. Sometimes, like a basic number is 127 00:06:33,400 --> 00:06:35,920 Speaker 1: just a combination of other numbers, just a combination to 128 00:06:36,000 --> 00:06:38,720 Speaker 1: other numbers. So what we're looking for is the minimal set, right, 129 00:06:38,760 --> 00:06:41,680 Speaker 1: We want the smallest number of constants, just like we 130 00:06:41,720 --> 00:06:44,240 Speaker 1: want the smallest number of physical laws. We don't want 131 00:06:44,279 --> 00:06:47,360 Speaker 1: to describe five thousand forces. We wanted to have one 132 00:06:47,400 --> 00:06:51,240 Speaker 1: force that describes everything. All the features of electromagnetism. We've 133 00:06:51,240 --> 00:06:54,080 Speaker 1: tied them up so nicely into a few equations with 134 00:06:54,120 --> 00:06:56,760 Speaker 1: a small number of numbers in them. So we're always 135 00:06:56,800 --> 00:06:59,479 Speaker 1: working to reduce the number of ideas and then the 136 00:06:59,520 --> 00:07:02,520 Speaker 1: number of parameters of those ideas. And we're not talking 137 00:07:02,560 --> 00:07:05,920 Speaker 1: about things like pie or e, right, which are sort 138 00:07:05,920 --> 00:07:09,400 Speaker 1: of mathematical or geometric constants in the universe. We're talking 139 00:07:09,440 --> 00:07:12,160 Speaker 1: more about physical constants, right, Yeah, things that you have 140 00:07:12,280 --> 00:07:15,040 Speaker 1: to measure, right, not just geometrical stuff that you could 141 00:07:15,080 --> 00:07:18,120 Speaker 1: calculate without having access to the universe. Things you have 142 00:07:18,200 --> 00:07:20,640 Speaker 1: to go out and actually measure. Because things like pie 143 00:07:20,640 --> 00:07:24,160 Speaker 1: and e are like sort of like basic constants in mathematics, 144 00:07:24,680 --> 00:07:27,280 Speaker 1: you know, which is sort of abstract. We're talking about 145 00:07:27,320 --> 00:07:30,320 Speaker 1: the constants in the universe that seemed to be there 146 00:07:30,400 --> 00:07:33,720 Speaker 1: that sort of define how things work. Yes, things that 147 00:07:33,840 --> 00:07:37,000 Speaker 1: if you change them, the nature of the universe would change. 148 00:07:37,200 --> 00:07:39,920 Speaker 1: Things would be different. You wouldn't have chemistry anymore, or 149 00:07:39,960 --> 00:07:42,600 Speaker 1: you wouldn't have stars, or you'd have more stars, or 150 00:07:42,840 --> 00:07:45,880 Speaker 1: you know, if different forces would be more powerful, or 151 00:07:46,040 --> 00:07:48,320 Speaker 1: we'd be made out of different kinds of particles. You know, 152 00:07:48,440 --> 00:07:51,120 Speaker 1: this kind of stuff that fundamentally changed our description of 153 00:07:51,120 --> 00:07:53,840 Speaker 1: the universe. But you're right, we don't know how many 154 00:07:53,920 --> 00:07:57,200 Speaker 1: constants we actually need right now. We need quite a 155 00:07:57,240 --> 00:07:59,280 Speaker 1: few to describe in the number. But if we had 156 00:07:59,280 --> 00:08:02,000 Speaker 1: the ultimate theory, how many constants would it happen? It 157 00:08:02,080 --> 00:08:04,720 Speaker 1: maybe one, maybe five, maybe ten, Maybe you have pie 158 00:08:04,800 --> 00:08:09,320 Speaker 1: number of constants. What does that even mean? It means 159 00:08:09,360 --> 00:08:11,160 Speaker 1: I just blew your mind, Daniel. Well, you know we 160 00:08:11,200 --> 00:08:13,440 Speaker 1: talked about how in Steven Wolfram's world there are two 161 00:08:13,520 --> 00:08:15,960 Speaker 1: point seven dimensions, so maybe you can have three point 162 00:08:16,000 --> 00:08:21,160 Speaker 1: one four numbers. Me and Stephen Wolfram are at the forefront. Well, 163 00:08:21,200 --> 00:08:23,960 Speaker 1: I pulled our listeners who are willing to participate in 164 00:08:24,360 --> 00:08:27,840 Speaker 1: virtual person on the street interviews and ask them this 165 00:08:27,960 --> 00:08:30,840 Speaker 1: question about the basic constants of the universe. And if 166 00:08:30,960 --> 00:08:33,599 Speaker 1: you would like to participate in these virtual person on 167 00:08:33,640 --> 00:08:36,360 Speaker 1: the street interviews, just right to us two questions at 168 00:08:36,440 --> 00:08:39,600 Speaker 1: Daniel and Jorge dot com. And you can also display 169 00:08:39,640 --> 00:08:42,480 Speaker 1: your knowledge or lack thereof on the podcast. So think 170 00:08:42,480 --> 00:08:44,960 Speaker 1: about it for a second. If someone asked you, what 171 00:08:45,040 --> 00:08:47,840 Speaker 1: are the basic constants of the universe? What would you answer? 172 00:08:48,160 --> 00:08:51,200 Speaker 1: Here's what people had to say this one. It's easy. 173 00:08:51,559 --> 00:08:56,360 Speaker 1: I don't know the gravitational constant and Avogadro constant. Other 174 00:08:56,400 --> 00:08:59,560 Speaker 1: than light speed, I would say that pie and oiler's 175 00:08:59,600 --> 00:09:02,760 Speaker 1: number also constants of the universe. At It's just like 176 00:09:02,840 --> 00:09:07,280 Speaker 1: things that we've measured. Well, I don't know. Well, they 177 00:09:07,280 --> 00:09:09,240 Speaker 1: gave us one hint of the speed of light, but 178 00:09:09,840 --> 00:09:12,600 Speaker 1: I think based on other podcasts that I've listened to 179 00:09:12,679 --> 00:09:15,760 Speaker 1: and learned from them, I think entropy might be a constant. 180 00:09:16,880 --> 00:09:21,720 Speaker 1: Gravity is a constant. And my last guest would be 181 00:09:21,840 --> 00:09:26,360 Speaker 1: maybe thermodynamics. I think physics, the you know, the standard 182 00:09:26,400 --> 00:09:28,679 Speaker 1: model of physics as we know it is constant. Right, 183 00:09:29,360 --> 00:09:35,920 Speaker 1: coals one equals one um? What else equals one pie? 184 00:09:35,920 --> 00:09:41,679 Speaker 1: There's Avogadro's number from ancient chemistry, listens plank mass, plank, 185 00:09:41,800 --> 00:09:49,600 Speaker 1: lenks um, Boltzman's constant reintropy. I think there was a 186 00:09:49,720 --> 00:09:52,800 Speaker 1: Daniel Why I explained the universe episode onto my dynamics. 187 00:09:52,800 --> 00:09:59,760 Speaker 1: I mentioned that the gravitational constant, elementary charge, the exponent 188 00:09:59,840 --> 00:10:03,880 Speaker 1: of the radius, the radius squared, and uh Gaussian formula, 189 00:10:04,480 --> 00:10:09,280 Speaker 1: and probably, I guess also called Maxwell's equations, death and taxes. 190 00:10:10,040 --> 00:10:16,200 Speaker 1: And there's also the charge of an electron and um 191 00:10:16,400 --> 00:10:21,080 Speaker 1: maybe the mass of the part of fundamental particles that 192 00:10:21,240 --> 00:10:24,679 Speaker 1: have mass. I know there are several constants in the universe, 193 00:10:24,679 --> 00:10:27,440 Speaker 1: however I can't remember most of them. The ones I 194 00:10:27,480 --> 00:10:32,040 Speaker 1: do remember are the speed of light, the gravitational constant, 195 00:10:32,520 --> 00:10:36,040 Speaker 1: and planks constant. Alright, some pretty good answer, is man? 196 00:10:36,120 --> 00:10:38,640 Speaker 1: Some of these I've never even heard of. Death and taxes? 197 00:10:38,679 --> 00:10:41,680 Speaker 1: You never heard it before? You know, what are taxes? 198 00:10:41,720 --> 00:10:44,760 Speaker 1: I don't understand. Is that what I keep playing any 199 00:10:44,840 --> 00:10:46,960 Speaker 1: letters in the midid Do you live in the sovereign 200 00:10:47,000 --> 00:10:50,599 Speaker 1: state of Jorge? Maybe I'll ask my accountant. But you know, 201 00:10:50,600 --> 00:10:53,480 Speaker 1: a lot of people are are talking about real physical 202 00:10:53,559 --> 00:10:57,800 Speaker 1: things like light speed and soul and entropy and the 203 00:10:57,840 --> 00:11:00,520 Speaker 1: speed of light. Yeah, people are saying things that are 204 00:11:00,960 --> 00:11:04,040 Speaker 1: sort of parameters of physical theories. But these are not. 205 00:11:04,160 --> 00:11:08,440 Speaker 1: Actually the basic constants that physicists talk about the speed 206 00:11:08,480 --> 00:11:12,080 Speaker 1: of light, planks constant, the gravitational constant. They seem basic, 207 00:11:12,520 --> 00:11:16,400 Speaker 1: but they're actually susceptible to sort of arbitrary definitions because 208 00:11:16,400 --> 00:11:19,360 Speaker 1: they're expressed in terms of human units. Oh, I see, 209 00:11:19,559 --> 00:11:22,679 Speaker 1: Meaning that, for example, the speed of light could be 210 00:11:22,720 --> 00:11:25,440 Speaker 1: a constant, but the constant wouldn't be three hundred thousand 211 00:11:25,520 --> 00:11:29,200 Speaker 1: meters per second, yeah, because that's subject to units. Yeah, 212 00:11:29,240 --> 00:11:31,160 Speaker 1: so let's get into that, Like what do we mean 213 00:11:31,240 --> 00:11:34,880 Speaker 1: by a basic physical constant? And one important thing is 214 00:11:34,920 --> 00:11:38,200 Speaker 1: that it should be dimensionless, like it shouldn't have units. 215 00:11:38,440 --> 00:11:41,920 Speaker 1: It shouldn't be expressed in terms of like furlongs per fortnite, 216 00:11:42,080 --> 00:11:44,800 Speaker 1: you know, or gallons per second or something. It should 217 00:11:44,840 --> 00:11:48,160 Speaker 1: just be a pure number, like a pure number without unit, 218 00:11:48,280 --> 00:11:50,959 Speaker 1: without units, like is a number without units, pies a 219 00:11:51,000 --> 00:11:53,520 Speaker 1: number without units. But it's not a physical constant because 220 00:11:53,520 --> 00:11:55,800 Speaker 1: it doesn't need to be measured with experiment, right, you 221 00:11:55,840 --> 00:11:58,000 Speaker 1: can do it in a simulation or on the computer 222 00:11:58,080 --> 00:12:00,560 Speaker 1: or something. But we're talking about physical instance that have 223 00:12:00,640 --> 00:12:02,800 Speaker 1: to be measured, and those are things like we'll get 224 00:12:02,800 --> 00:12:05,120 Speaker 1: into the whole list, but you know, things like the 225 00:12:05,160 --> 00:12:08,079 Speaker 1: mass of a particle relative to the mass of another particle, 226 00:12:08,480 --> 00:12:12,160 Speaker 1: like ratios, like ratios, which wouldn't change if you suddenly 227 00:12:12,280 --> 00:12:14,480 Speaker 1: change what it means if you change, like from English 228 00:12:14,559 --> 00:12:18,560 Speaker 1: units to international unit exactly. And there's two important reasons 229 00:12:18,640 --> 00:12:21,439 Speaker 1: why you have to use numbers without units. The first 230 00:12:21,559 --> 00:12:23,760 Speaker 1: is you want to look at the number and know 231 00:12:23,800 --> 00:12:26,360 Speaker 1: what it means, and it doesn't mean anything if it's 232 00:12:26,400 --> 00:12:29,840 Speaker 1: relative to some stick in Paris, or you know the 233 00:12:29,960 --> 00:12:33,400 Speaker 1: length of somebody's foot a hundred years ago. Right. If 234 00:12:33,400 --> 00:12:35,400 Speaker 1: you're interested in knowing a number, then you don't want 235 00:12:35,400 --> 00:12:38,360 Speaker 1: to express in terms of human units because it's totally arbitrary, 236 00:12:38,400 --> 00:12:40,120 Speaker 1: and you could change that number. It could be a 237 00:12:40,200 --> 00:12:43,440 Speaker 1: hundred eighties six thousand miles per second or three times 238 00:12:43,440 --> 00:12:46,240 Speaker 1: ten meters per second. Like, you can't look at the 239 00:12:46,280 --> 00:12:49,000 Speaker 1: number and say it means anything if it's defined relative 240 00:12:49,040 --> 00:12:51,559 Speaker 1: to something totally arbitrary. You need a basic constant to 241 00:12:51,640 --> 00:12:55,520 Speaker 1: feel classic, like not subject to the whims of man 242 00:12:55,600 --> 00:12:58,120 Speaker 1: and what they consider foot. That's right, And it's more 243 00:12:58,160 --> 00:13:01,840 Speaker 1: than just you know, having an maturity standard. You also 244 00:13:02,000 --> 00:13:05,000 Speaker 1: need the basic constants to be dimensionless so that you 245 00:13:05,040 --> 00:13:07,680 Speaker 1: can tell if they're changing, if they're changing, then you 246 00:13:07,679 --> 00:13:10,720 Speaker 1: can tell what's changing. I see, you don't want a 247 00:13:10,760 --> 00:13:14,640 Speaker 1: meter to be, you know, the length of a length 248 00:13:14,679 --> 00:13:17,760 Speaker 1: of putty, because the length of putty might change. That's right, 249 00:13:17,960 --> 00:13:20,240 Speaker 1: of the length of putty might change. But also like 250 00:13:20,400 --> 00:13:22,480 Speaker 1: you know, say you're interested in the question, you know, 251 00:13:22,559 --> 00:13:25,120 Speaker 1: does the speed of light change? Right? This is a 252 00:13:25,200 --> 00:13:27,560 Speaker 1: question you see in science all the time. It turns 253 00:13:27,600 --> 00:13:30,000 Speaker 1: out it doesn't actually have the meaning that you think 254 00:13:30,040 --> 00:13:32,640 Speaker 1: it does when you drill down into it, because it's 255 00:13:32,679 --> 00:13:36,800 Speaker 1: so subject to human conventions. Depends on how you're defining units. 256 00:13:36,880 --> 00:13:39,920 Speaker 1: And in fact, in Night three we change what we 257 00:13:39,960 --> 00:13:42,520 Speaker 1: meant by the speed of light. Really, yeah, the speed 258 00:13:42,520 --> 00:13:47,120 Speaker 1: of light change in after three, it doesn't make any 259 00:13:47,160 --> 00:13:50,320 Speaker 1: sense to measure the speed of light. And that's because 260 00:13:50,360 --> 00:13:53,480 Speaker 1: before nine eight three, we defind the meter to be 261 00:13:53,480 --> 00:13:56,240 Speaker 1: the length of some rod in Paris, and the second 262 00:13:56,320 --> 00:13:59,559 Speaker 1: to be um you know, ten trillion oscillations of C 263 00:13:59,720 --> 00:14:01,600 Speaker 1: C and one thirty three. So we had the meter 264 00:14:01,960 --> 00:14:03,680 Speaker 1: and we had the second, and then you could go 265 00:14:03,720 --> 00:14:05,559 Speaker 1: out and you could measure the speed of light. You 266 00:14:05,559 --> 00:14:07,760 Speaker 1: could say, how far did a beam of light go 267 00:14:07,880 --> 00:14:10,600 Speaker 1: in ten seconds? And I'll measure that distance with my 268 00:14:11,200 --> 00:14:13,280 Speaker 1: ruler from Paris or my copy of it, and get 269 00:14:13,320 --> 00:14:17,480 Speaker 1: a number. Cool. But then a bunch of people got 270 00:14:17,520 --> 00:14:20,600 Speaker 1: together and decided that will keep the second as like 271 00:14:20,680 --> 00:14:23,720 Speaker 1: you know, the number of oscillations of set three. But 272 00:14:23,800 --> 00:14:25,520 Speaker 1: then we're going to fix the speed of light. We're 273 00:14:25,520 --> 00:14:27,880 Speaker 1: going to define it to be something. So we just 274 00:14:28,000 --> 00:14:30,560 Speaker 1: pick a number. We say it's two point nine nine 275 00:14:30,560 --> 00:14:35,400 Speaker 1: whatever times ten per second. Okay, So once you do that, 276 00:14:35,480 --> 00:14:38,440 Speaker 1: you don't have to define the meter anymore. It's already 277 00:14:38,480 --> 00:14:42,440 Speaker 1: defined by the other constants. Right, You've got time, and 278 00:14:42,480 --> 00:14:44,920 Speaker 1: you've got speed because you have the speed of light. 279 00:14:45,280 --> 00:14:48,440 Speaker 1: So a meter then is just defined as how far 280 00:14:48,640 --> 00:14:51,800 Speaker 1: light goes in a certain tiny fraction of a second. 281 00:14:52,240 --> 00:14:54,760 Speaker 1: So the meter is now defined to be a fraction 282 00:14:54,960 --> 00:14:58,400 Speaker 1: of a light second. Right. Light seconds are the reference 283 00:14:58,440 --> 00:15:01,600 Speaker 1: for distance now the under mental way we measure distance 284 00:15:01,640 --> 00:15:05,240 Speaker 1: to the universe instead of that crazy rod in Paris, 285 00:15:05,560 --> 00:15:08,720 Speaker 1: and we're used to measuring distances in terms of time, 286 00:15:08,840 --> 00:15:12,200 Speaker 1: like a light year is a unit for distance to 287 00:15:12,240 --> 00:15:15,520 Speaker 1: the stars. Right, that's familiar. Well, a meter is now 288 00:15:15,600 --> 00:15:17,600 Speaker 1: just a tiny bit of a light second. It's not 289 00:15:17,840 --> 00:15:21,560 Speaker 1: defined anymore by a rod in Paris. It's measured by 290 00:15:21,600 --> 00:15:25,640 Speaker 1: how far light goes in that tiny slice of a second. Yeah, 291 00:15:25,680 --> 00:15:28,240 Speaker 1: we flipped it. And so now you ask, well, a 292 00:15:28,360 --> 00:15:30,480 Speaker 1: meter is now measured instead of the speed of light 293 00:15:30,520 --> 00:15:34,920 Speaker 1: being measured. Isn't even time variable? You know, according to relativity? 294 00:15:35,000 --> 00:15:37,760 Speaker 1: You know how close you are to a gravitational object, 295 00:15:38,320 --> 00:15:41,440 Speaker 1: you know, like, isn't even the oscillations of of season 296 00:15:41,480 --> 00:15:46,320 Speaker 1: one thirty three also may be subject to you know, relativity. Yeah, absolutely, 297 00:15:46,800 --> 00:15:50,400 Speaker 1: And that's why you want to focus on dimensionless constants, right. 298 00:15:50,800 --> 00:15:52,640 Speaker 1: But the point here, the point I was trying to make, 299 00:15:52,720 --> 00:15:55,880 Speaker 1: is that, like you can't even tell in this example 300 00:15:56,240 --> 00:15:58,840 Speaker 1: if the speed of light is changing, or you know, 301 00:15:58,880 --> 00:16:01,640 Speaker 1: the length scale the uni verse itself is changing. It 302 00:16:01,680 --> 00:16:03,920 Speaker 1: depends on if you're defining the speed of light to 303 00:16:03,920 --> 00:16:06,800 Speaker 1: be fixed and measuring the meter relative to that, or 304 00:16:06,800 --> 00:16:09,000 Speaker 1: you're defining the meter to be fixed and measuring the 305 00:16:09,040 --> 00:16:11,800 Speaker 1: speed of light relative to that. So the way to 306 00:16:11,840 --> 00:16:14,400 Speaker 1: figure out if the universe is changing, if the physics 307 00:16:14,440 --> 00:16:17,840 Speaker 1: of the universe are changing in time or static, which 308 00:16:17,880 --> 00:16:19,440 Speaker 1: is really what we're trying to get at, where we 309 00:16:19,480 --> 00:16:22,200 Speaker 1: measure these numbers and see if they're changing, is to 310 00:16:22,320 --> 00:16:25,960 Speaker 1: define only dimensionless numbers, numbers without any units because they're 311 00:16:25,960 --> 00:16:30,000 Speaker 1: not subject to any of these totally arbitrary definitions. All right, 312 00:16:30,080 --> 00:16:32,960 Speaker 1: So that's kind of what a basic constant is. It's 313 00:16:33,120 --> 00:16:36,240 Speaker 1: a number that defines some kind of ratio about physical 314 00:16:36,280 --> 00:16:38,720 Speaker 1: things in the universe, which may be there at the 315 00:16:38,800 --> 00:16:41,320 Speaker 1: end when we discover the equation of the universe. Yeah, 316 00:16:41,320 --> 00:16:43,640 Speaker 1: and I really like thinking about this this way, like 317 00:16:43,680 --> 00:16:48,360 Speaker 1: thinking about measuring distances in terms of times. You know, 318 00:16:48,400 --> 00:16:50,080 Speaker 1: it makes a lot of sense when you think about, 319 00:16:50,640 --> 00:16:53,120 Speaker 1: you know, measuring distances to stars in terms of the 320 00:16:53,160 --> 00:16:55,760 Speaker 1: speed of light um and it just shows you that 321 00:16:55,880 --> 00:16:58,040 Speaker 1: all these numbers we measure, like the speed of light, 322 00:16:58,120 --> 00:17:01,240 Speaker 1: they're really just ways to convert between meters and seconds. 323 00:17:01,240 --> 00:17:05,640 Speaker 1: They're just like translations between arbitrary human conventions. So they're 324 00:17:05,640 --> 00:17:08,439 Speaker 1: not actually fundamental. The things that are fundamental are things 325 00:17:08,520 --> 00:17:10,480 Speaker 1: we'll talk about, you know, a little bit. But yes, 326 00:17:10,800 --> 00:17:14,200 Speaker 1: we're looking for sort of a minimal list of dimensionless 327 00:17:14,240 --> 00:17:18,240 Speaker 1: quantities which would change the world if if they changed, right, 328 00:17:18,280 --> 00:17:21,240 Speaker 1: So let's maybe get into what is that minimal list 329 00:17:21,440 --> 00:17:24,399 Speaker 1: of basic constants in the universe and what we know 330 00:17:24,440 --> 00:17:27,200 Speaker 1: about them so far. But first let's take a quick break, 331 00:17:40,440 --> 00:17:44,199 Speaker 1: all right, Daniel, we're talking about this constant topic that 332 00:17:44,280 --> 00:17:48,320 Speaker 1: keeps coming up in physics, which is constants and what 333 00:17:48,520 --> 00:17:51,120 Speaker 1: is and what isn't changing about the universe? And are 334 00:17:51,160 --> 00:17:54,600 Speaker 1: there constants in the basic equation of the universe? And 335 00:17:54,640 --> 00:17:58,160 Speaker 1: there are how many? And what are they? And let's 336 00:17:58,200 --> 00:18:00,000 Speaker 1: just get out of the way. It's probably forty two, 337 00:18:00,040 --> 00:18:03,720 Speaker 1: but you know, we still have to check. Well, forty 338 00:18:03,720 --> 00:18:05,760 Speaker 1: two would be wonderful because it'd be kind of a 339 00:18:05,760 --> 00:18:08,280 Speaker 1: good joke, but it would also be kind of disappointing 340 00:18:08,359 --> 00:18:11,520 Speaker 1: because forty two is a big number. You're never happy, Daniel. 341 00:18:12,600 --> 00:18:16,880 Speaker 1: All answers have both good and bad consequence. I'm constantly disappointed. Now. 342 00:18:17,000 --> 00:18:19,679 Speaker 1: What we're looking for. What we'd love is to have 343 00:18:19,720 --> 00:18:22,199 Speaker 1: a small number of constants, because that would tell us 344 00:18:22,200 --> 00:18:24,560 Speaker 1: that we're close, right like the way we're trying to 345 00:18:24,600 --> 00:18:28,000 Speaker 1: boil down the universe to one particle and one rule, 346 00:18:28,560 --> 00:18:30,800 Speaker 1: that tells you something deep about the universe. If your 347 00:18:31,080 --> 00:18:33,159 Speaker 1: list of particles and your list of rules about how 348 00:18:33,200 --> 00:18:36,200 Speaker 1: they interact is fifty pages long, it tells you you're 349 00:18:36,200 --> 00:18:38,560 Speaker 1: not really close to the answer. So we want to 350 00:18:38,560 --> 00:18:40,879 Speaker 1: get down to a small number of constants because we 351 00:18:40,960 --> 00:18:43,199 Speaker 1: think those are probably fundamental. We want to look at 352 00:18:43,240 --> 00:18:46,360 Speaker 1: those and say, you know, the theory of the universe 353 00:18:46,359 --> 00:18:48,640 Speaker 1: has the number seven in it. What does that mean? 354 00:18:48,880 --> 00:18:52,280 Speaker 1: Why is the universe seven? Ish? You know, why seven 355 00:18:52,280 --> 00:18:54,640 Speaker 1: and not six? And we're looking for that moment where 356 00:18:54,600 --> 00:18:57,600 Speaker 1: we get to ask that philosophical question about the universe. 357 00:18:57,640 --> 00:19:00,200 Speaker 1: And you can't really do that if you suspect your 358 00:19:00,200 --> 00:19:02,840 Speaker 1: list of numbers is sort of an artifact of not 359 00:19:02,880 --> 00:19:05,439 Speaker 1: having gotten there yet. Do you think maybe the last 360 00:19:05,600 --> 00:19:08,000 Speaker 1: number in the universe. Do you think it's an integer 361 00:19:08,600 --> 00:19:10,800 Speaker 1: like a whole number, or do you think it's gonna 362 00:19:10,800 --> 00:19:12,679 Speaker 1: be some weird numbers? I don't know. You know a 363 00:19:12,680 --> 00:19:16,280 Speaker 1: lot of particle theorists like numbers that are close to one. 364 00:19:16,960 --> 00:19:19,040 Speaker 1: They think all the numbers and there should just be one. 365 00:19:19,160 --> 00:19:22,080 Speaker 1: They're like, we got one, we don't need anymore. Yeah, 366 00:19:22,200 --> 00:19:24,520 Speaker 1: And they wonder when they find a number that's not one. 367 00:19:24,960 --> 00:19:27,679 Speaker 1: You know, they see things and like, well, why is 368 00:19:28,119 --> 00:19:31,400 Speaker 1: electromagnetism so much stronger than the weak force? And why 369 00:19:31,440 --> 00:19:33,439 Speaker 1: is it so much stronger than gravity? And they have 370 00:19:33,560 --> 00:19:36,520 Speaker 1: these numbers and that reflect the relative strength of those forces, 371 00:19:36,520 --> 00:19:38,480 Speaker 1: and they wonder, why is it not one? They look 372 00:19:38,520 --> 00:19:41,440 Speaker 1: for symmetry and simplicity, so anytime they see a number 373 00:19:41,480 --> 00:19:44,040 Speaker 1: that's not one, they get suspicious because they think maybe 374 00:19:44,040 --> 00:19:46,720 Speaker 1: there's a reason, maybe there's a simpler way to express things, 375 00:19:46,720 --> 00:19:48,359 Speaker 1: where all these things are just one. And that's how 376 00:19:48,400 --> 00:19:50,480 Speaker 1: they conduct your social life too. They're like, there's more 377 00:19:50,480 --> 00:19:53,280 Speaker 1: than one people here, what's going on? This is not 378 00:19:53,359 --> 00:19:56,840 Speaker 1: what I ordered? They have one friend at a time, 379 00:19:57,359 --> 00:20:00,040 Speaker 1: you know, one friend at a time. It's like of 380 00:20:00,080 --> 00:20:03,480 Speaker 1: one else is apparently that's right. So we are not 381 00:20:03,560 --> 00:20:06,080 Speaker 1: there yet. We are not down to one constant. In fact, 382 00:20:06,200 --> 00:20:08,920 Speaker 1: we sort of have an embarrassing number of constants so far. 383 00:20:09,040 --> 00:20:12,840 Speaker 1: We have twenty six basic constants of the unit. Twenty six. 384 00:20:13,080 --> 00:20:16,040 Speaker 1: Oh man, that seems like a significant number in itself, 385 00:20:16,440 --> 00:20:19,360 Speaker 1: seems like a special number because it's what two times thirteen, Yeah, 386 00:20:19,359 --> 00:20:22,240 Speaker 1: and thirteen is the prime number. Yeah, but that means 387 00:20:22,320 --> 00:20:26,240 Speaker 1: twenty six isn't right, so it's much less exciting. Alright, 388 00:20:26,480 --> 00:20:28,520 Speaker 1: what do you mean? We have twenty six constants? Meaning 389 00:20:28,640 --> 00:20:30,679 Speaker 1: in all of physics and all of the equations that 390 00:20:30,720 --> 00:20:34,520 Speaker 1: we currently have about the universe, there twenty six numbers 391 00:20:34,560 --> 00:20:37,119 Speaker 1: that you can't break down anymore or that are not 392 00:20:37,200 --> 00:20:39,200 Speaker 1: related to each other. If you wrote down the whole 393 00:20:39,200 --> 00:20:42,080 Speaker 1: standard model of particle physics, and you have to put 394 00:20:42,080 --> 00:20:44,439 Speaker 1: all the numbers into all the four strengths and all 395 00:20:44,440 --> 00:20:46,760 Speaker 1: the mass particles and all the way things change to 396 00:20:46,760 --> 00:20:48,480 Speaker 1: each other. There are a lot of numbers in there, 397 00:20:48,520 --> 00:20:51,560 Speaker 1: like thousands of thousands of numbers, but most of those 398 00:20:51,640 --> 00:20:54,840 Speaker 1: numbers come from other numbers, Like how long does the 399 00:20:54,920 --> 00:20:58,119 Speaker 1: muan live? That's a number, but you can calculate that 400 00:20:58,200 --> 00:21:00,560 Speaker 1: based on the muan mass and the elect on mass 401 00:21:00,600 --> 00:21:02,800 Speaker 1: and the fourth strength between them. And so if you 402 00:21:02,880 --> 00:21:05,720 Speaker 1: boil it down to the minimal set of numbers that 403 00:21:05,760 --> 00:21:08,560 Speaker 1: you needed to find all those other numbers, right, the 404 00:21:08,600 --> 00:21:12,040 Speaker 1: ones that, according to our understanding currently are the knobs 405 00:21:12,119 --> 00:21:14,800 Speaker 1: of the universe, then you get twenty six. Like I 406 00:21:14,840 --> 00:21:16,520 Speaker 1: toss a ball up into the air and catch it, 407 00:21:16,720 --> 00:21:19,960 Speaker 1: you can maybe derive that time using other numbers. Yeah, exactly. 408 00:21:20,359 --> 00:21:22,320 Speaker 1: If I know the mass to the electron relative to 409 00:21:22,320 --> 00:21:25,600 Speaker 1: the gravitational constant and stuff like that, I can derive 410 00:21:25,960 --> 00:21:28,960 Speaker 1: most of physics from just a few numbers. All right, Well, 411 00:21:29,000 --> 00:21:31,880 Speaker 1: then let's let's talk numbers. Danuel, What what are these 412 00:21:31,960 --> 00:21:33,800 Speaker 1: twenty six? Break it down for us. What are these 413 00:21:33,800 --> 00:21:37,480 Speaker 1: twenty six apparently basic constants of the universe that we 414 00:21:37,520 --> 00:21:41,280 Speaker 1: have right now. Yeah, So there are sort of three categories. 415 00:21:41,359 --> 00:21:44,640 Speaker 1: One is like the strength of forces, another is the 416 00:21:44,680 --> 00:21:48,000 Speaker 1: masses of particles and how they mix, and then there's 417 00:21:48,080 --> 00:21:52,119 Speaker 1: the cosmological constant and its own category. The first ones 418 00:21:52,160 --> 00:21:54,560 Speaker 1: are really really interesting, and these are the fourth ones. 419 00:21:54,760 --> 00:21:56,720 Speaker 1: The most important one, the one that you hear about 420 00:21:56,720 --> 00:21:58,520 Speaker 1: a lot and I think reveals a lot about what 421 00:21:58,560 --> 00:22:02,439 Speaker 1: we mean by a engineless physical constant. Is this one 422 00:22:02,520 --> 00:22:07,600 Speaker 1: called the fine structure constant. Fine structure constant, all right, 423 00:22:07,720 --> 00:22:10,359 Speaker 1: I'm intrigued. It's a weird name. It's called the fine 424 00:22:10,440 --> 00:22:13,400 Speaker 1: structure constant because it comes from when people were trying 425 00:22:13,400 --> 00:22:17,159 Speaker 1: to understand the nature of the atom and the structure 426 00:22:17,320 --> 00:22:19,760 Speaker 1: of the spectra that it emitted. And so what it 427 00:22:19,800 --> 00:22:23,280 Speaker 1: really reveals sort of the strength of the electromagnetic force. 428 00:22:23,760 --> 00:22:26,159 Speaker 1: And so this number here tells you about the power 429 00:22:26,200 --> 00:22:30,040 Speaker 1: of electromagnetism as probed by the internals of the atom, 430 00:22:30,040 --> 00:22:32,280 Speaker 1: but it turns out to be a fundamental number of 431 00:22:32,320 --> 00:22:35,240 Speaker 1: the universe. What does it mean? Is it like how 432 00:22:35,520 --> 00:22:38,200 Speaker 1: how attracted an electron is to a proton or something 433 00:22:38,240 --> 00:22:42,560 Speaker 1: like that. Yeah, it's something like the probability for an 434 00:22:42,560 --> 00:22:46,040 Speaker 1: electron to emit a photon, and that number is a 435 00:22:46,119 --> 00:22:51,240 Speaker 1: vacuum or um. Will electrons only emit photons inside electromagnetic fields, 436 00:22:51,280 --> 00:22:55,240 Speaker 1: of course, And that number everyone knows that. And that 437 00:22:55,359 --> 00:22:58,679 Speaker 1: number turns out to be one over one thirty seven. 438 00:22:58,800 --> 00:23:02,280 Speaker 1: What exact one over one thirty seven, not exactly. For 439 00:23:02,320 --> 00:23:04,400 Speaker 1: a long time people thought it was exactly one over 440 00:23:04,440 --> 00:23:06,919 Speaker 1: on seven, and there was a big mystery in physics 441 00:23:07,000 --> 00:23:09,800 Speaker 1: like why that number. And Richard Feynman likes to say 442 00:23:09,840 --> 00:23:11,520 Speaker 1: that if you were a physicist and you were ever 443 00:23:11,600 --> 00:23:14,399 Speaker 1: like stranded in a foreign city, you just hold up 444 00:23:14,520 --> 00:23:17,280 Speaker 1: a piece of cardboard that says one over seven on it, 445 00:23:17,400 --> 00:23:19,639 Speaker 1: and some other physicists will see that and know that 446 00:23:19,640 --> 00:23:23,880 Speaker 1: you're a physicist, come rescuing. It's like a code. I'm 447 00:23:23,920 --> 00:23:25,760 Speaker 1: not sure if you're stranded in a city you want, 448 00:23:26,080 --> 00:23:28,600 Speaker 1: what you need is a physicist to rescue you. But 449 00:23:29,280 --> 00:23:31,600 Speaker 1: you know, let's leave that aside. And um. Alright, So 450 00:23:32,080 --> 00:23:34,840 Speaker 1: one of these constants of the universe is kind of 451 00:23:35,600 --> 00:23:38,360 Speaker 1: how likely an electron is to admit a photon. Yeah, 452 00:23:38,400 --> 00:23:41,920 Speaker 1: it's like the probability for an electron to emit a photon, 453 00:23:42,400 --> 00:23:46,320 Speaker 1: and it's it's actually expressed in terms of other numbers 454 00:23:46,320 --> 00:23:49,120 Speaker 1: that you will find familiar. Like the way you calculated 455 00:23:49,680 --> 00:23:55,560 Speaker 1: is the charge of the electron squared divided by planks 456 00:23:55,600 --> 00:23:59,040 Speaker 1: constant h bar times the speed of light, and so 457 00:23:59,080 --> 00:24:01,800 Speaker 1: it has all these other of familiar things built into it. 458 00:24:02,480 --> 00:24:05,199 Speaker 1: But when you put all those things together, the units cancel, 459 00:24:05,760 --> 00:24:08,040 Speaker 1: Like you get up a number that has no units 460 00:24:08,080 --> 00:24:10,840 Speaker 1: in it, And that means something really really deep. Um, 461 00:24:10,920 --> 00:24:12,399 Speaker 1: what do you mean? What I mean is that it 462 00:24:12,440 --> 00:24:15,000 Speaker 1: tells you something about the importance of the speed of light. 463 00:24:15,040 --> 00:24:17,320 Speaker 1: It tells you, for example, that the speed of light 464 00:24:17,440 --> 00:24:20,560 Speaker 1: is not actually a fundamental constant. That if you change 465 00:24:20,720 --> 00:24:23,240 Speaker 1: the speed of light, but then you also change these 466 00:24:23,280 --> 00:24:26,600 Speaker 1: other numbers inside the fine structure constant to keep the 467 00:24:26,640 --> 00:24:29,720 Speaker 1: fine constructure constant the same, you would not be able 468 00:24:29,760 --> 00:24:32,320 Speaker 1: to tell the difference. The universe would work the same way. 469 00:24:32,359 --> 00:24:35,120 Speaker 1: As long as you keep these numbers the same, then 470 00:24:35,200 --> 00:24:37,439 Speaker 1: you can change the speed of light and the strength 471 00:24:37,560 --> 00:24:40,439 Speaker 1: electromagnetic force, and you could not do an experiment that 472 00:24:40,520 --> 00:24:42,600 Speaker 1: showed that anything had change, Like it doesn't have any 473 00:24:42,680 --> 00:24:45,879 Speaker 1: consequences anywhere else in the universe. That's right. When if 474 00:24:45,880 --> 00:24:47,520 Speaker 1: you change the speed of light, Wooden, you we know 475 00:24:47,640 --> 00:24:50,199 Speaker 1: it is like, oh, it takes longer for light to 476 00:24:50,240 --> 00:24:52,520 Speaker 1: come to us from the sun. If you only change 477 00:24:52,520 --> 00:24:55,280 Speaker 1: the speed of light, which means that you're effectively changing 478 00:24:55,320 --> 00:24:57,840 Speaker 1: the fine structure constant, then yes. But if you change 479 00:24:57,840 --> 00:25:00,640 Speaker 1: the speed of light and you also change like the 480 00:25:00,720 --> 00:25:04,800 Speaker 1: charge of the electron or planks constant, or you manipulated 481 00:25:04,840 --> 00:25:06,800 Speaker 1: these things in such a way to keep the fine 482 00:25:06,800 --> 00:25:09,560 Speaker 1: structure constant the ratio of these things the same, then 483 00:25:09,680 --> 00:25:12,520 Speaker 1: you could not tell the difference. It's like, Okay, distance 484 00:25:12,520 --> 00:25:16,720 Speaker 1: now means something different. But you know, the electromagnetic force 485 00:25:16,840 --> 00:25:20,800 Speaker 1: is now stronger. So what are you using to measure distance. 486 00:25:20,840 --> 00:25:24,359 Speaker 1: You're using you know, the photons admitted by electrons or something. 487 00:25:24,600 --> 00:25:27,520 Speaker 1: So you cannot devise an experiment that is sensitive to 488 00:25:27,960 --> 00:25:32,199 Speaker 1: changes of just planks constant or just the speed of light. Um, 489 00:25:32,240 --> 00:25:36,560 Speaker 1: if you keep the fine structure constant fixed, somebody could 490 00:25:36,680 --> 00:25:40,040 Speaker 1: change these things and nobody in the universe would even notice. 491 00:25:40,119 --> 00:25:42,800 Speaker 1: Nobody in the universe could even notice, you know. Imagine 492 00:25:42,800 --> 00:25:44,560 Speaker 1: a simpler example, like, I feel like, I feel like 493 00:25:44,560 --> 00:25:48,280 Speaker 1: this is a conspiracy. Suddenly I feel nervous. It's about 494 00:25:48,280 --> 00:25:51,600 Speaker 1: our world is relative to our units. Imagine, for example, 495 00:25:51,680 --> 00:25:54,600 Speaker 1: somebody came in and change the universe so that now 496 00:25:55,080 --> 00:25:59,680 Speaker 1: every distance was doubled. This distance between all particles was doubled. Suddenly, 497 00:26:00,119 --> 00:26:02,840 Speaker 1: could you notice? Well? Sure, but not if then they 498 00:26:03,080 --> 00:26:05,840 Speaker 1: also increase the power of all the forces so that 499 00:26:05,920 --> 00:26:09,040 Speaker 1: things didn't seem as far, and they increase the maximum 500 00:26:09,040 --> 00:26:12,119 Speaker 1: speed you could go. Right, then it would take you 501 00:26:12,200 --> 00:26:15,160 Speaker 1: just as long to get from here to work, and 502 00:26:15,359 --> 00:26:18,119 Speaker 1: your rulers would also change, right, so you would say, oh, 503 00:26:18,160 --> 00:26:20,360 Speaker 1: I'm still the same high as that was yesterday. It's 504 00:26:20,359 --> 00:26:22,800 Speaker 1: like if somebody just scaled up the universe, but they 505 00:26:22,880 --> 00:26:26,399 Speaker 1: made sure that everything worked same, would we even notice? Exactly? Like, 506 00:26:26,440 --> 00:26:28,720 Speaker 1: could somebody bottle up the whole universe into a little 507 00:26:28,840 --> 00:26:31,840 Speaker 1: bottle and then made sure that all the knobs were 508 00:26:31,840 --> 00:26:34,680 Speaker 1: also changed that we wouldn't notice the difference. It could happen. 509 00:26:34,800 --> 00:26:36,680 Speaker 1: It could happen. And that's why we focus on these 510 00:26:36,680 --> 00:26:41,000 Speaker 1: dimensionless quantities, because you can't change those without changing the physics. 511 00:26:41,480 --> 00:26:43,639 Speaker 1: You can change the things that they express, you know, 512 00:26:43,680 --> 00:26:46,760 Speaker 1: this fine structure constant. You can change the dimension full 513 00:26:46,800 --> 00:26:50,280 Speaker 1: of the unit quantities inside them. But if you change 514 00:26:50,320 --> 00:26:52,840 Speaker 1: these fine structure constants, then there's no way to hide 515 00:26:52,840 --> 00:26:55,840 Speaker 1: that they do seem like basic constants of the university. 516 00:26:56,040 --> 00:26:58,600 Speaker 1: They do. And it's like a basic ratio of the universe, 517 00:26:58,680 --> 00:27:01,439 Speaker 1: you know, just like pies, like the ratio of you know, 518 00:27:01,520 --> 00:27:04,439 Speaker 1: the radius and the circumference. This is like the basic 519 00:27:04,640 --> 00:27:07,520 Speaker 1: ratio of matter and how it moves in the world. 520 00:27:07,520 --> 00:27:09,400 Speaker 1: And now I'm gonna disappoint you because it turns out 521 00:27:09,440 --> 00:27:13,199 Speaker 1: it's not actually constant. No. No, but it's not that 522 00:27:13,240 --> 00:27:16,040 Speaker 1: it's not constant in time. It's really weird and we're 523 00:27:16,040 --> 00:27:18,640 Speaker 1: gonna dig into this next week when you talk about renormalization. 524 00:27:19,200 --> 00:27:22,199 Speaker 1: But it depends on how fast you're going when you 525 00:27:22,280 --> 00:27:24,439 Speaker 1: measure it. Isn't that what I brought up earlier, like 526 00:27:24,840 --> 00:27:28,000 Speaker 1: relativity special relativity. Yeah, it's actually it's more about the 527 00:27:28,040 --> 00:27:30,680 Speaker 1: momentum you have relative to the thing that you're measuring, 528 00:27:31,000 --> 00:27:33,879 Speaker 1: rather than actual velocity. You just can't admit I was right, 529 00:27:34,400 --> 00:27:37,080 Speaker 1: You're always right, or hey, that's one constant of the 530 00:27:37,160 --> 00:27:41,640 Speaker 1: universe relatively speaking. All right, So that's that's a good flavor. 531 00:27:41,680 --> 00:27:43,600 Speaker 1: I think that gives us a good flavor for what 532 00:27:43,720 --> 00:27:47,000 Speaker 1: these constants mean. And it blows my mind that there 533 00:27:47,040 --> 00:27:49,520 Speaker 1: are twenty six of these that we think we know 534 00:27:49,560 --> 00:27:52,760 Speaker 1: about twenty six things that can't change or could change 535 00:27:52,760 --> 00:27:55,600 Speaker 1: internally but we wouldn't notice. Yeah, all right, Well, let's 536 00:27:55,600 --> 00:27:58,719 Speaker 1: get into the other kinds of constants in the universe 537 00:27:58,760 --> 00:28:01,320 Speaker 1: that we have and what they mean and whether or 538 00:28:01,400 --> 00:28:03,560 Speaker 1: not there are more of them. But first let's take 539 00:28:03,600 --> 00:28:18,600 Speaker 1: another quick break. All right, then, we're talking about the 540 00:28:18,640 --> 00:28:21,760 Speaker 1: basic constants of the universe that are not constant, but 541 00:28:22,080 --> 00:28:24,960 Speaker 1: we think are sort of constant consistently. Well, that's one 542 00:28:24,960 --> 00:28:27,840 Speaker 1: thing we don't know, right. We measure this thing, we've 543 00:28:27,920 --> 00:28:30,439 Speaker 1: measured a lot of different times, over many different years, 544 00:28:30,520 --> 00:28:32,639 Speaker 1: and we do not see it changing in time, and 545 00:28:32,640 --> 00:28:36,119 Speaker 1: so we say, maybe this is constant, and it's just 546 00:28:36,240 --> 00:28:38,040 Speaker 1: like the rest of science. We have no reason to 547 00:28:38,120 --> 00:28:40,320 Speaker 1: believe that you do an experiment today and you do 548 00:28:40,400 --> 00:28:42,320 Speaker 1: experiment in a week, you should get the same answer 549 00:28:42,320 --> 00:28:44,520 Speaker 1: in the same conditions. But it seems to be true. 550 00:28:44,920 --> 00:28:48,200 Speaker 1: We live in an empirical universe where you can repeat experiments, 551 00:28:48,480 --> 00:28:52,120 Speaker 1: and it seems like these numbers are fixed. We may discover, 552 00:28:52,240 --> 00:28:54,640 Speaker 1: if we keep doing science over a thousand years or 553 00:28:54,640 --> 00:28:57,840 Speaker 1: a million years, that they're very slowly varying, and that 554 00:28:57,880 --> 00:29:00,640 Speaker 1: would be fascinating, But so far they do seem constant. 555 00:29:00,760 --> 00:29:02,840 Speaker 1: All right, And so you're telling me that physicists have 556 00:29:03,000 --> 00:29:05,800 Speaker 1: twenty six of these constants, and some of them are 557 00:29:05,800 --> 00:29:08,480 Speaker 1: related to like how particles interact with each other and 558 00:29:08,480 --> 00:29:10,920 Speaker 1: how attracted they are to each other, but some of 559 00:29:11,000 --> 00:29:13,840 Speaker 1: them are also related to their masses. So tell me 560 00:29:13,960 --> 00:29:16,440 Speaker 1: about this, yea. So we have to the determine the forces. 561 00:29:16,520 --> 00:29:19,760 Speaker 1: One is the fine structure constant that tells you about electromagnetism. 562 00:29:19,920 --> 00:29:21,880 Speaker 1: There's a second one which tells you about the strong 563 00:29:21,960 --> 00:29:25,200 Speaker 1: nuclear force. But then most of these constants actually relate 564 00:29:25,280 --> 00:29:27,920 Speaker 1: to the particles, and that's because we just don't know 565 00:29:28,360 --> 00:29:31,480 Speaker 1: why the particle masses are what they are. Like, we 566 00:29:31,560 --> 00:29:35,400 Speaker 1: have twelve matter particles that make up the standard model. 567 00:29:35,760 --> 00:29:40,120 Speaker 1: There are six kinds of quirks up down, charm strange 568 00:29:40,280 --> 00:29:44,240 Speaker 1: top bottom. Those are six different particles with six different masses. 569 00:29:44,720 --> 00:29:48,880 Speaker 1: And then there's six leptons, electrons, muans, towels, and their 570 00:29:49,000 --> 00:29:52,959 Speaker 1: three neutrinos. So those are twelve particles and we do 571 00:29:53,040 --> 00:29:54,960 Speaker 1: not know why they have the masses they do. We 572 00:29:55,000 --> 00:29:57,560 Speaker 1: can't predict it, we can't calculate it. We don't even 573 00:29:57,560 --> 00:29:59,880 Speaker 1: see a pattern. And so we just have to put 574 00:30:00,200 --> 00:30:03,320 Speaker 1: one parameter when to mention this constant for each one. 575 00:30:03,960 --> 00:30:06,160 Speaker 1: You wish they were related, but so far they don't 576 00:30:06,200 --> 00:30:08,720 Speaker 1: seem to be. Yeah, we wish that. You know, the 577 00:30:08,840 --> 00:30:11,040 Speaker 1: muon was twice the mass of the electron and the 578 00:30:11,120 --> 00:30:14,520 Speaker 1: towel was four times the mass or there was some relationship, 579 00:30:15,040 --> 00:30:17,240 Speaker 1: so you could only fix one number that would determine 580 00:30:17,280 --> 00:30:19,160 Speaker 1: all the rest of them, and also that would give 581 00:30:19,240 --> 00:30:21,520 Speaker 1: us some insight to like why are there these other 582 00:30:21,600 --> 00:30:24,400 Speaker 1: particles and why are they heavier and stuff like that, 583 00:30:24,520 --> 00:30:27,480 Speaker 1: But we see no pattern at all. There's a huge range. 584 00:30:27,800 --> 00:30:31,320 Speaker 1: The electron is super duper light, the neutrinos are even lighter. 585 00:30:31,520 --> 00:30:35,200 Speaker 1: The top cork is like enormously heavy relative to all 586 00:30:35,280 --> 00:30:38,600 Speaker 1: the other ones. So there are some very general rough patterns, 587 00:30:38,600 --> 00:30:40,560 Speaker 1: but really nothing we can put our finger on. So 588 00:30:40,560 --> 00:30:42,680 Speaker 1: it's the masses of these particles. And I guess the 589 00:30:42,760 --> 00:30:44,760 Speaker 1: question is how do you measure these masses? Is it 590 00:30:44,880 --> 00:30:46,360 Speaker 1: like how much they weigh when you put them on 591 00:30:46,400 --> 00:30:49,520 Speaker 1: a scale in Paris, or you know, it more like 592 00:30:50,280 --> 00:30:53,040 Speaker 1: if you push a towel particle, how much does it move? 593 00:30:53,200 --> 00:30:55,320 Speaker 1: What he called the mass of these particles. Yeah, so 594 00:30:55,400 --> 00:30:57,880 Speaker 1: here we're talking about the rest mass, right, which means 595 00:30:57,880 --> 00:31:00,280 Speaker 1: how much energy it has essentially when it's at rest, 596 00:31:00,320 --> 00:31:03,680 Speaker 1: when you're in its reference frame, and it's hard to 597 00:31:03,720 --> 00:31:06,520 Speaker 1: measure because particles are very very small and their masses 598 00:31:06,520 --> 00:31:09,000 Speaker 1: are very very light. And so what we do instead 599 00:31:09,040 --> 00:31:10,959 Speaker 1: is we wait for one of these things to decay, 600 00:31:11,080 --> 00:31:15,440 Speaker 1: for example, and we measure the energy of the particles 601 00:31:15,440 --> 00:31:18,960 Speaker 1: that come out. So if a massive particle turns into 602 00:31:19,040 --> 00:31:22,360 Speaker 1: massless particles, then the mass of the original particle gets 603 00:31:22,360 --> 00:31:25,840 Speaker 1: turned into energy of those massless particles. We measure those 604 00:31:25,920 --> 00:31:29,160 Speaker 1: energies like the photons, etcetera. Then we can measure the 605 00:31:29,200 --> 00:31:31,960 Speaker 1: mass of the original particle, and so we can do 606 00:31:32,040 --> 00:31:33,840 Speaker 1: things like that, but it gets harder. The particles that 607 00:31:33,920 --> 00:31:37,000 Speaker 1: don't do that, like the electron stable, so there you 608 00:31:37,000 --> 00:31:39,160 Speaker 1: have to do things like put it in a magnetic 609 00:31:39,200 --> 00:31:42,280 Speaker 1: field and see how much it bends, because that's partially 610 00:31:42,280 --> 00:31:44,920 Speaker 1: determined by its mass. I guess it would be route 611 00:31:44,960 --> 00:31:47,120 Speaker 1: just to ask him what the mass. They don't like 612 00:31:47,200 --> 00:31:50,040 Speaker 1: to talk about it constantly, but they have to be 613 00:31:50,080 --> 00:31:52,600 Speaker 1: dimensionless numbers. And so what you could do is, because 614 00:31:52,640 --> 00:31:54,680 Speaker 1: I'm gonna fix the mass of the electron, and I 615 00:31:54,680 --> 00:31:56,880 Speaker 1: would measure everything relative to the mass of the electron. 616 00:31:57,360 --> 00:31:59,800 Speaker 1: But then the electron mass then is still a dimension 617 00:31:59,800 --> 00:32:02,120 Speaker 1: full number. And so what we do is we set 618 00:32:02,120 --> 00:32:06,040 Speaker 1: all these things relative to the gravitational constant big G, 619 00:32:06,240 --> 00:32:09,120 Speaker 1: which has the same units of mass, and so all 620 00:32:09,120 --> 00:32:12,240 Speaker 1: these things are relative to big G. Big G meaning 621 00:32:12,640 --> 00:32:15,800 Speaker 1: like nine eight per second square. No, that's little little 622 00:32:15,840 --> 00:32:20,760 Speaker 1: G is But just you said louder, little G is 623 00:32:20,840 --> 00:32:23,600 Speaker 1: the force of gravity at the surface of the Earth, right, 624 00:32:23,640 --> 00:32:26,000 Speaker 1: And that's a number that's important to us, irrelevant, but 625 00:32:26,080 --> 00:32:29,160 Speaker 1: definitely not a constant of the universe. It just depends 626 00:32:29,160 --> 00:32:30,840 Speaker 1: on the size of the Earth and how much mass 627 00:32:30,880 --> 00:32:33,680 Speaker 1: it is, and this kind of stuff. Big G is 628 00:32:33,720 --> 00:32:36,760 Speaker 1: the number that goes inside Newton's equation and then later 629 00:32:36,840 --> 00:32:40,240 Speaker 1: also in Einstein's field equations for gravity that determines the 630 00:32:40,280 --> 00:32:44,600 Speaker 1: strength of the gravitational force. It's more basic. It's more basic, yeah, 631 00:32:44,960 --> 00:32:47,360 Speaker 1: and it should be true all over the universe. And 632 00:32:47,400 --> 00:32:49,680 Speaker 1: so we measure the mass of these particles relative to 633 00:32:49,800 --> 00:32:52,560 Speaker 1: that because usually what you're interested in is actually the 634 00:32:52,680 --> 00:32:56,440 Speaker 1: ratio of inertial mass two forces, right, like how much 635 00:32:56,440 --> 00:32:58,360 Speaker 1: gravity are you putting on this thing? How much is 636 00:32:58,360 --> 00:33:01,520 Speaker 1: it going to accelerate? That depends on how much mass 637 00:33:01,600 --> 00:33:04,040 Speaker 1: it has, and so we measure these things relative to 638 00:33:04,040 --> 00:33:06,680 Speaker 1: big g also to keep them dimensionless. And so it 639 00:33:06,720 --> 00:33:09,720 Speaker 1: seems that we have twelve particles and their masses. That 640 00:33:10,000 --> 00:33:12,600 Speaker 1: seems to be basic about the universe. And are these 641 00:33:12,800 --> 00:33:15,560 Speaker 1: constants sort of like define structure constant where I could, 642 00:33:15,600 --> 00:33:17,400 Speaker 1: you know, change the mass of an electron and I 643 00:33:17,400 --> 00:33:20,080 Speaker 1: wouldn't notice. Now, if you change the fine structure constant, 644 00:33:20,120 --> 00:33:22,160 Speaker 1: you would definitely notice. But if you change one of 645 00:33:22,160 --> 00:33:24,480 Speaker 1: the numbers inside of it, you you might not notice. 646 00:33:24,520 --> 00:33:26,200 Speaker 1: So as long as it's a constant, then we would 647 00:33:26,240 --> 00:33:28,120 Speaker 1: have noticed. Yeah. And so if you change the mass 648 00:33:28,160 --> 00:33:30,840 Speaker 1: of the electron, for example, and made it heavier than 649 00:33:30,880 --> 00:33:33,960 Speaker 1: the muan, then a lot of things would change, because 650 00:33:33,960 --> 00:33:36,960 Speaker 1: then the electron wouldn't be stable anymore. It could decay 651 00:33:37,120 --> 00:33:40,560 Speaker 1: into muans. And then maybe our atoms would we have 652 00:33:40,800 --> 00:33:44,040 Speaker 1: muans in them instead of electrons, right, we'd be muonic 653 00:33:44,120 --> 00:33:47,160 Speaker 1: matter instead of electronic matter. But what you're I guess 654 00:33:47,200 --> 00:33:49,000 Speaker 1: what you're saying is that the speed of light could change. 655 00:33:49,040 --> 00:33:51,720 Speaker 1: But as long as you change everything else, we wouldn't notice. 656 00:33:52,080 --> 00:33:54,240 Speaker 1: And as long as you also don't change the masses 657 00:33:54,240 --> 00:33:56,440 Speaker 1: of the particles, yeah, but if you change these massive 658 00:33:56,440 --> 00:34:00,360 Speaker 1: the particles relative to the gravitational constant, you'll definitely notice, 659 00:34:00,960 --> 00:34:03,440 Speaker 1: and especially if you change their relative orders, you know, 660 00:34:03,480 --> 00:34:06,160 Speaker 1: because there's a hierarchy there, and if you change those 661 00:34:06,160 --> 00:34:08,120 Speaker 1: things then we will definitely notice. It would change the 662 00:34:08,120 --> 00:34:10,960 Speaker 1: way physics and chemistry works. All right, Okay, we have 663 00:34:11,000 --> 00:34:13,400 Speaker 1: twenty six constants. Two of them are about the forces 664 00:34:13,400 --> 00:34:18,040 Speaker 1: of the universe, twelve are about the masses of the particles, 665 00:34:18,080 --> 00:34:20,359 Speaker 1: and some of them are also sort of related to 666 00:34:20,840 --> 00:34:24,040 Speaker 1: how particles mixed together. Right, and then we have the 667 00:34:24,280 --> 00:34:28,920 Speaker 1: cosmological constants, which we talked about in a previous episode. Yeah, 668 00:34:29,120 --> 00:34:31,400 Speaker 1: and so all the other ones relate to the particles 669 00:34:31,400 --> 00:34:33,200 Speaker 1: and how they mix and and all of that stuff. 670 00:34:33,200 --> 00:34:36,759 Speaker 1: There's three more for the force particles Higgs, W, and Z, 671 00:34:37,320 --> 00:34:39,879 Speaker 1: and then eight for how the particles turn into each 672 00:34:39,920 --> 00:34:42,279 Speaker 1: other and how often it happens. But then you write 673 00:34:42,280 --> 00:34:44,600 Speaker 1: the big one, the one at the end, is the 674 00:34:44,640 --> 00:34:48,240 Speaker 1: cosmological constant. That's the one that tells us how fast 675 00:34:48,280 --> 00:34:51,319 Speaker 1: the expansion of the universe is accelerating, or if it's 676 00:34:51,320 --> 00:34:55,560 Speaker 1: accelerating at all, and it determines like the overall shape 677 00:34:55,600 --> 00:34:59,080 Speaker 1: of the universe. But you guys, don't go in between here, 678 00:34:59,360 --> 00:35:02,440 Speaker 1: it's either but little tiny particles or the entire universe. 679 00:35:03,640 --> 00:35:07,440 Speaker 1: It turns out little tiny particles determine the entire universe. 680 00:35:07,560 --> 00:35:10,000 Speaker 1: Do you think maybe the cosmological constant is related to 681 00:35:10,040 --> 00:35:12,760 Speaker 1: something about particles? It could be right. People have tried 682 00:35:12,800 --> 00:35:15,000 Speaker 1: to calculate it. They say, let's try to predict the 683 00:35:15,000 --> 00:35:18,640 Speaker 1: cosmological constant. If it's in fact just the energy of 684 00:35:18,680 --> 00:35:21,440 Speaker 1: empty space, like the vacuum of empty space it becomes, 685 00:35:21,520 --> 00:35:24,200 Speaker 1: for example, from the Higgs Boson field, then we should 686 00:35:24,239 --> 00:35:26,560 Speaker 1: be able to calculate it. And they've tried. But the 687 00:35:26,640 --> 00:35:29,800 Speaker 1: number they get is different from the number we measure 688 00:35:30,120 --> 00:35:32,839 Speaker 1: by ten to the hundred and twenty a little bit. 689 00:35:33,200 --> 00:35:35,480 Speaker 1: We're not even close. Yeah, we're not even close to 690 00:35:35,480 --> 00:35:37,520 Speaker 1: getting that one right. But we'd love to. You're right, 691 00:35:37,520 --> 00:35:39,839 Speaker 1: we'd love to be able to derive this number from 692 00:35:39,920 --> 00:35:41,719 Speaker 1: the other numbers, because then we could take it off 693 00:35:41,719 --> 00:35:43,680 Speaker 1: our list and we'd be down to a thin and 694 00:35:43,719 --> 00:35:46,839 Speaker 1: trim twenty five numbers, and you would make a little 695 00:35:46,840 --> 00:35:50,879 Speaker 1: bit of progress in the constant define the universe. All right, Well, 696 00:35:50,880 --> 00:35:53,120 Speaker 1: we uh, there are twenty six right now that physicists 697 00:35:53,160 --> 00:35:55,239 Speaker 1: can't break down anymore. And is that it do you 698 00:35:55,239 --> 00:35:57,400 Speaker 1: think maybe there are more? Do you think there should 699 00:35:57,400 --> 00:36:00,160 Speaker 1: be less? Are you guys aiming to collect more? Are 700 00:36:00,440 --> 00:36:03,080 Speaker 1: or to you know, do some spring cleaning and get 701 00:36:03,160 --> 00:36:05,040 Speaker 1: rid of some of these. I think there should definitely 702 00:36:05,040 --> 00:36:07,760 Speaker 1: be a fewer, right, we should have one number, maybe 703 00:36:08,120 --> 00:36:10,360 Speaker 1: maybe even zero. I'd love a theory the universe that 704 00:36:10,400 --> 00:36:14,520 Speaker 1: has zero numbers. Yeah, well, zero numbers in terms of physics, 705 00:36:14,560 --> 00:36:16,399 Speaker 1: but maybe like if you can get it to come 706 00:36:16,440 --> 00:36:18,960 Speaker 1: down to a mathematical constant, then that would be cool, 707 00:36:19,040 --> 00:36:20,719 Speaker 1: that's what you mean, right, Yeah, maybe you could have 708 00:36:20,800 --> 00:36:22,719 Speaker 1: pie and E and I and there. It would be 709 00:36:22,719 --> 00:36:26,080 Speaker 1: cool if there are no physical parameters in the fundamental theory. 710 00:36:26,640 --> 00:36:29,480 Speaker 1: But we're sort of working in the other direction right now, Like, 711 00:36:29,680 --> 00:36:32,720 Speaker 1: if anything, we're moving in the direction of adding more numbers. 712 00:36:32,760 --> 00:36:36,400 Speaker 1: Because this theory we've been talking about, the standard model 713 00:36:36,560 --> 00:36:40,160 Speaker 1: that describes the universe, we know, doesn't actually describe everything 714 00:36:40,160 --> 00:36:42,200 Speaker 1: in the universe, and so as we add to it 715 00:36:42,320 --> 00:36:45,160 Speaker 1: to describe those other bits, were just figuring out that 716 00:36:45,200 --> 00:36:47,399 Speaker 1: we're gonna need more numbers. Yeah, because it turns out 717 00:36:47,400 --> 00:36:51,560 Speaker 1: that apparently the standard model only covers about five percent 718 00:36:52,200 --> 00:36:55,279 Speaker 1: of the entire universe, right, Yeah, And you know, it's 719 00:36:55,280 --> 00:36:57,880 Speaker 1: a staggering achievement so far. But there's a lot of 720 00:36:57,880 --> 00:37:00,319 Speaker 1: stuff out there it does not describe. And so what 721 00:37:00,440 --> 00:37:04,320 Speaker 1: about dark matter? For example, if dark matter is fifty 722 00:37:04,480 --> 00:37:07,239 Speaker 1: kinds of particles and we don't understand why they are 723 00:37:07,239 --> 00:37:09,680 Speaker 1: fifty and why they all have different masses, Boom, that's 724 00:37:09,719 --> 00:37:12,800 Speaker 1: fifty more numbers right there, or maybe could have one number, 725 00:37:12,960 --> 00:37:14,920 Speaker 1: or I wonder if it could help you cancel some 726 00:37:14,960 --> 00:37:17,640 Speaker 1: of your numbers. Dark matter has the same structure as 727 00:37:17,719 --> 00:37:20,319 Speaker 1: normal matter, and now we understand the masses because we 728 00:37:20,360 --> 00:37:22,680 Speaker 1: see more of the pattern and it reveals itself and 729 00:37:22,760 --> 00:37:24,919 Speaker 1: we get some insights and it helps us figure it out. 730 00:37:25,160 --> 00:37:27,880 Speaker 1: That's why we're always struggling to attack the parts of 731 00:37:27,880 --> 00:37:30,560 Speaker 1: the universe we don't understand, because they could be the 732 00:37:30,600 --> 00:37:34,040 Speaker 1: puzzle piece that lets us see the whole picture. And so, yeah, 733 00:37:34,160 --> 00:37:36,440 Speaker 1: there could be more out there, because there's a lot 734 00:37:36,520 --> 00:37:40,080 Speaker 1: of the universe we don't know about. And you're also 735 00:37:40,120 --> 00:37:42,960 Speaker 1: telling me that they're not really Maybe even constants, like 736 00:37:43,080 --> 00:37:45,680 Speaker 1: maybe the mass of the electron could be changing, is 737 00:37:45,680 --> 00:37:48,919 Speaker 1: that possible, or you know, this fine structure constant could 738 00:37:48,960 --> 00:37:51,400 Speaker 1: also be different, not just in time, but in different 739 00:37:51,440 --> 00:37:53,480 Speaker 1: parts of the universe. Yeah, we don't know if these 740 00:37:53,480 --> 00:37:56,319 Speaker 1: things are constant in space and in time. It's sort 741 00:37:56,360 --> 00:37:59,680 Speaker 1: of like a hypothesis. It's the simplest description so far, 742 00:38:00,000 --> 00:38:02,680 Speaker 1: because we haven't seen them change, and they seem really 743 00:38:02,680 --> 00:38:05,560 Speaker 1: basic and fundamental. But because we don't know where they 744 00:38:05,560 --> 00:38:08,120 Speaker 1: come from and why they're important, why we have this 745 00:38:08,160 --> 00:38:11,840 Speaker 1: set not a smaller set, we can't say anything about 746 00:38:11,840 --> 00:38:15,439 Speaker 1: whether they really are constant. It's just an observation. It's 747 00:38:15,480 --> 00:38:16,840 Speaker 1: like if you live in l A. And you go 748 00:38:16,880 --> 00:38:19,080 Speaker 1: outside and you're like, hey, every day is sunny. Well, 749 00:38:19,120 --> 00:38:21,120 Speaker 1: that doesn't mean it's gonna be sunny every day. There 750 00:38:21,160 --> 00:38:22,880 Speaker 1: might be a reason why it's sunny or in l 751 00:38:22,920 --> 00:38:25,360 Speaker 1: A than it is in New York, but unless you 752 00:38:25,440 --> 00:38:27,319 Speaker 1: understand the reason for it, you can't really make an 753 00:38:27,320 --> 00:38:30,239 Speaker 1: accurate prediction. But you know, I like looking forward to 754 00:38:30,280 --> 00:38:32,799 Speaker 1: the end days when we have that theory and we're 755 00:38:32,840 --> 00:38:35,439 Speaker 1: looking at it and we're asking questions about what those 756 00:38:35,560 --> 00:38:37,759 Speaker 1: numbers mean. So I went around and I did a 757 00:38:37,760 --> 00:38:40,600 Speaker 1: little informal survey in my department. I asked some of 758 00:38:40,640 --> 00:38:43,279 Speaker 1: the particle theorists. I said, how many numbers do you 759 00:38:43,320 --> 00:38:46,680 Speaker 1: expect to see in a theory of everything expect to 760 00:38:46,680 --> 00:38:51,040 Speaker 1: be or want there to be. I think, I think, 761 00:38:51,080 --> 00:38:56,080 Speaker 1: isn't it the same seem you know, you're asking whether 762 00:38:56,080 --> 00:38:59,400 Speaker 1: they expect to be disappointed? Essentially? Yeah, kind of. So 763 00:38:59,440 --> 00:39:02,400 Speaker 1: what did they say? How many numbers did they predict 764 00:39:02,440 --> 00:39:05,680 Speaker 1: our final theory of the universe will have? I was surprised. 765 00:39:05,800 --> 00:39:07,960 Speaker 1: I was expecting them to say one number, and that 766 00:39:08,080 --> 00:39:11,240 Speaker 1: numbers shouldn't be one or close to one one number 767 00:39:11,360 --> 00:39:14,839 Speaker 1: one quantity, Yeah, exactly, but they really didn't know. They said, 768 00:39:14,840 --> 00:39:17,000 Speaker 1: you know, could be one number, could be seven numbers. 769 00:39:17,160 --> 00:39:19,880 Speaker 1: You know, they expected to be smallish, you know, maybe 770 00:39:19,960 --> 00:39:22,720 Speaker 1: less than ten numbers, but they wouldn't give a firm prediction. 771 00:39:23,120 --> 00:39:24,600 Speaker 1: And then I asked them, well, what do you expect 772 00:39:24,600 --> 00:39:26,839 Speaker 1: those numbers to look like? Like? Should they be huge 773 00:39:26,920 --> 00:39:29,040 Speaker 1: numbers or small numbers? Should they all be close to 774 00:39:29,120 --> 00:39:31,440 Speaker 1: one and one of them? A friend of mine, Tim Tait, 775 00:39:31,520 --> 00:39:33,400 Speaker 1: sort of blew my mind, and he said, it doesn't 776 00:39:33,400 --> 00:39:36,040 Speaker 1: really matter if it's close to one, because close to 777 00:39:36,040 --> 00:39:38,799 Speaker 1: one is just relative to the integers, and who knows 778 00:39:38,840 --> 00:39:43,280 Speaker 1: if like equally spaced numbers one unit apart means anything anyway. 779 00:39:43,560 --> 00:39:46,400 Speaker 1: So he's like thinking about like whether integers are a 780 00:39:46,480 --> 00:39:50,719 Speaker 1: kind of unit. But yeah, exactly, questioning the nature of 781 00:39:50,840 --> 00:39:54,560 Speaker 1: numbers themselves. Yes, yes, And you know, it doesn't even 782 00:39:54,600 --> 00:39:58,160 Speaker 1: make sense to have mathematics in terms of equally space numbers, 783 00:39:58,200 --> 00:40:01,160 Speaker 1: because you know, the numbers were all there. Just declaring 784 00:40:01,200 --> 00:40:04,279 Speaker 1: these equally space numbers to be meaningful, you know, it's 785 00:40:04,320 --> 00:40:06,640 Speaker 1: sort of a human convention. Let's just throw everything out 786 00:40:06,640 --> 00:40:10,560 Speaker 1: the door, Daniel, numbers don't mean anything. Distance, the word constant, Yeah, 787 00:40:10,960 --> 00:40:13,440 Speaker 1: that doesn't mean anything. Well, that's why we try to 788 00:40:13,520 --> 00:40:15,760 Speaker 1: drill down, because we try to peel away the human 789 00:40:15,800 --> 00:40:18,200 Speaker 1: bias and look at the universe the way it actually is, 790 00:40:18,640 --> 00:40:21,680 Speaker 1: which is why you know, I like stories about alien 791 00:40:21,880 --> 00:40:26,359 Speaker 1: scientists where the aliens don't have differentiated bodies that they're 792 00:40:26,400 --> 00:40:29,160 Speaker 1: like part of some larger mass, and so they never 793 00:40:29,200 --> 00:40:31,319 Speaker 1: come up with this idea of integers because they never 794 00:40:31,360 --> 00:40:35,000 Speaker 1: count like me and you and indistinct objects, and they 795 00:40:35,040 --> 00:40:38,200 Speaker 1: aren't linked to this kind of assumption in their mathematics, 796 00:40:38,200 --> 00:40:40,400 Speaker 1: and that makes them think differently about the universe. And 797 00:40:40,800 --> 00:40:43,399 Speaker 1: that's what we're trying to do here, not specifically meet 798 00:40:43,520 --> 00:40:47,040 Speaker 1: those weird aliens, but get out of our human bias 799 00:40:47,080 --> 00:40:50,480 Speaker 1: and think about the universe as close to objectively as 800 00:40:50,520 --> 00:40:52,960 Speaker 1: we can, right, Yeah, I think the lesson here is 801 00:40:53,000 --> 00:40:54,960 Speaker 1: don't go to a physics theorist if you want the 802 00:40:55,000 --> 00:40:59,400 Speaker 1: concept simplified. That's what I'm here for. I'm trying to 803 00:40:59,440 --> 00:41:04,239 Speaker 1: filter the sixth theory for everybody. All Right, Well, that 804 00:41:04,360 --> 00:41:08,080 Speaker 1: was a pretty cool discussion. I feel like it's amazing 805 00:41:08,120 --> 00:41:10,759 Speaker 1: to think that there are constants that you know, kind 806 00:41:10,800 --> 00:41:13,600 Speaker 1: of define our universe and that maybe in another universe 807 00:41:13,640 --> 00:41:16,959 Speaker 1: those numbers are different and they're having different discussions about 808 00:41:16,960 --> 00:41:18,560 Speaker 1: the whole thing. Yeah, And it could be that we 809 00:41:18,560 --> 00:41:20,440 Speaker 1: get down the theory of everything and it has a 810 00:41:20,520 --> 00:41:22,920 Speaker 1: few numbers in it, and we wonder, like why those numbers, 811 00:41:22,960 --> 00:41:25,080 Speaker 1: And you know, it could be that those numbers are 812 00:41:25,120 --> 00:41:27,759 Speaker 1: just an accident that there are zillions universes and they're 813 00:41:27,760 --> 00:41:30,799 Speaker 1: all set randomly, or it could be that, you know, 814 00:41:30,840 --> 00:41:32,839 Speaker 1: they were set for some other reason, or it could 815 00:41:32,920 --> 00:41:36,359 Speaker 1: be that they could only be those numbers. It will 816 00:41:36,400 --> 00:41:39,239 Speaker 1: be a fascinating moment when if we finally get there, 817 00:41:39,280 --> 00:41:43,319 Speaker 1: there could be no answer. You're preparing to be disappointed. 818 00:41:43,560 --> 00:41:46,120 Speaker 1: I'm always looking forward to the future the universe, expecting 819 00:41:46,120 --> 00:41:49,279 Speaker 1: it to be chock full of insights and discoveries. And 820 00:41:49,360 --> 00:41:52,319 Speaker 1: mind blowing revelations. That's why I'm helping out. You're a 821 00:41:52,360 --> 00:41:57,760 Speaker 1: constant optimist, and yeah, exactly so far, I've revealed exactly 822 00:41:57,840 --> 00:42:00,680 Speaker 1: zero truths about the universe in my professional career, but 823 00:42:00,880 --> 00:42:04,919 Speaker 1: I am optimistic. Hey, zero is a basic constantly the universe. 824 00:42:05,480 --> 00:42:08,840 Speaker 1: You know, Douglas Adam would be proud today. Zero What 825 00:42:08,880 --> 00:42:11,000 Speaker 1: I've accomplished today, the number of pairs of pants I 826 00:42:11,080 --> 00:42:16,279 Speaker 1: put on today. Well, we hope you guys enjoyed that. 827 00:42:16,760 --> 00:42:19,239 Speaker 1: Thank you for joining us, and think about whether the 828 00:42:19,280 --> 00:42:22,000 Speaker 1: universe around you is constant and what that means. See 829 00:42:22,040 --> 00:42:32,320 Speaker 1: you next time. Thanks for listening, and remember that Daniel 830 00:42:32,360 --> 00:42:34,880 Speaker 1: and Jorge Explain the Universe is a production of I 831 00:42:35,120 --> 00:42:38,560 Speaker 1: Heart Radio. For more podcasts for my Heart Radio, visit 832 00:42:38,560 --> 00:42:42,080 Speaker 1: the I Heart Radio Apple Apple Podcasts, or wherever you 833 00:42:42,160 --> 00:42:43,680 Speaker 1: listen to your favorite shows.