1 00:00:07,240 --> 00:00:10,440 Speaker 1: I just think it's fascinating that it's such a fundamental 2 00:00:10,840 --> 00:00:14,720 Speaker 1: force in the universe, right, Like, it's basically the thing 3 00:00:14,800 --> 00:00:20,000 Speaker 1: that builds galaxies and keeps planets moving right, and gives 4 00:00:20,000 --> 00:00:21,880 Speaker 1: structure to the entire cosmos. 5 00:00:22,239 --> 00:00:25,079 Speaker 2: That's right. On the largest scale, it's actually the most 6 00:00:25,200 --> 00:00:28,360 Speaker 2: important force. It's the reason why things look the way 7 00:00:28,360 --> 00:00:31,080 Speaker 2: they do. It's the reason why our planet is round, 8 00:00:31,120 --> 00:00:33,200 Speaker 2: it's the reason why we're on the planet. 9 00:00:33,479 --> 00:00:37,120 Speaker 1: It's pretty important, and yet we don't know a lot 10 00:00:37,159 --> 00:00:40,560 Speaker 1: about it, right Like, there's some really deep and strange 11 00:00:40,880 --> 00:00:41,800 Speaker 1: mysteries about it. 12 00:00:41,960 --> 00:00:44,200 Speaker 2: On one hand, we have a theory which works really 13 00:00:44,200 --> 00:00:46,360 Speaker 2: really well. On the other hand, we have questions about 14 00:00:46,360 --> 00:00:48,120 Speaker 2: it which seems really really basic. 15 00:00:48,560 --> 00:00:51,040 Speaker 1: And not only that, it's very different than all the 16 00:00:51,040 --> 00:00:52,600 Speaker 1: other forces of nature. 17 00:00:53,159 --> 00:00:55,840 Speaker 2: That's right, one of these things is not like the 18 00:00:55,920 --> 00:00:56,440 Speaker 2: other ones. 19 00:01:15,080 --> 00:01:17,160 Speaker 1: Hi, I'm Hohe, I'm a cartoonist. 20 00:01:16,880 --> 00:01:19,000 Speaker 2: And I'm Daniel. I'm a particle physicist. 21 00:01:19,240 --> 00:01:22,920 Speaker 1: And this is our podcast Daniel and Jorge explain the universe. 22 00:01:22,680 --> 00:01:25,199 Speaker 2: In which a cartoonist and a physicists try to figure 23 00:01:25,200 --> 00:01:28,600 Speaker 2: out how to make the universe understandable to anybody. 24 00:01:28,880 --> 00:01:32,560 Speaker 1: Yeah, and today on the podcast we are examining a 25 00:01:32,680 --> 00:01:43,640 Speaker 1: very heavy topic, gravity and specifically why is gravity so. 26 00:01:43,840 --> 00:01:48,800 Speaker 2: Weak and strange. Gravity, as we said earlier, is something 27 00:01:48,800 --> 00:01:51,400 Speaker 2: which controls the structure of the universe. I mean, the 28 00:01:51,480 --> 00:01:53,720 Speaker 2: reason the Solar system looks the way it does is 29 00:01:53,760 --> 00:01:56,560 Speaker 2: because of gravity. The reason the Earth is round is 30 00:01:56,560 --> 00:01:59,440 Speaker 2: because of gravity. The reason we have galaxies is because 31 00:01:59,440 --> 00:02:00,000 Speaker 2: of gravity. 32 00:02:00,280 --> 00:02:02,960 Speaker 1: The reason we weigh so much, it is because of gravity. Right, 33 00:02:03,000 --> 00:02:04,920 Speaker 1: it's not my belt. 34 00:02:06,520 --> 00:02:08,320 Speaker 2: No, that's because of late night cake eating. 35 00:02:10,080 --> 00:02:13,320 Speaker 1: But it's such a fundamental force of nature, right, Like 36 00:02:13,360 --> 00:02:16,519 Speaker 1: it's present in our everyday life. We spend a lot 37 00:02:16,560 --> 00:02:20,560 Speaker 1: of time thinking about gravity, right, how not to fall down, 38 00:02:20,840 --> 00:02:23,560 Speaker 1: how not to drop things, how to go up buildings, 39 00:02:23,600 --> 00:02:24,639 Speaker 1: how to go down buildings. 40 00:02:24,720 --> 00:02:26,760 Speaker 2: Right, that's right. It seems like one of the most 41 00:02:26,760 --> 00:02:29,320 Speaker 2: important forces. I mean, if you ask people, you know, 42 00:02:29,480 --> 00:02:31,680 Speaker 2: to name a force or what kind of forces they 43 00:02:31,760 --> 00:02:34,040 Speaker 2: experience in their life, gravity is the one that's present 44 00:02:34,080 --> 00:02:36,880 Speaker 2: in their lives. Right, you're climbing upstairs, you're fighting gravity, 45 00:02:36,880 --> 00:02:39,560 Speaker 2: your trip, you fall down, you're feeling gravity. You look 46 00:02:39,600 --> 00:02:42,440 Speaker 2: around you. The shape of things is controlled by gravity, 47 00:02:42,760 --> 00:02:46,440 Speaker 2: and that's why it's particularly strange that gravity is the 48 00:02:46,480 --> 00:02:50,320 Speaker 2: weakest force of all the forces we've discovered, it's by 49 00:02:50,440 --> 00:02:51,280 Speaker 2: far the weakest. 50 00:02:51,480 --> 00:02:54,360 Speaker 1: Yeah, it's really strange to hear you say that, Like, 51 00:02:54,440 --> 00:02:56,880 Speaker 1: how can gravity be weak? Like you know, like it's 52 00:02:57,200 --> 00:02:59,960 Speaker 1: it's keeping the whole Earth together, it's making the entire 53 00:03:00,080 --> 00:03:04,440 Speaker 1: higher planet swing around going a circle basically, right. Without gravity, 54 00:03:04,480 --> 00:03:05,959 Speaker 1: we would just shoot off into space. 55 00:03:06,280 --> 00:03:09,280 Speaker 2: That's right. It's a really strange situation. And there's other 56 00:03:09,320 --> 00:03:12,520 Speaker 2: things about gravity we don't understand as well. It's really strange. 57 00:03:12,520 --> 00:03:15,119 Speaker 2: It doesn't play well with the other forces. It's very, 58 00:03:15,200 --> 00:03:18,080 Speaker 2: very weak. It's a total mystery to science, except that 59 00:03:18,120 --> 00:03:20,560 Speaker 2: we have a theory which works beautifully right. We can 60 00:03:20,600 --> 00:03:24,080 Speaker 2: calculate exactly how mercury orbits the Sun. We can send 61 00:03:24,080 --> 00:03:26,920 Speaker 2: things into outer space and know with to millimeter precision 62 00:03:26,960 --> 00:03:29,079 Speaker 2: exactly where they're going to land. We have a working 63 00:03:29,120 --> 00:03:32,320 Speaker 2: theory that we can use, right, but we don't understand 64 00:03:32,360 --> 00:03:34,840 Speaker 2: it on a conceptual level. We have these basic, deep 65 00:03:34,920 --> 00:03:38,040 Speaker 2: questions about what gravity is and how the universe works 66 00:03:38,080 --> 00:03:38,600 Speaker 2: because of it. 67 00:03:38,800 --> 00:03:41,160 Speaker 1: So it's a weird question, and maybe one of the 68 00:03:41,160 --> 00:03:44,080 Speaker 1: people hadn't thought about before. So Daniel went out as 69 00:03:44,160 --> 00:03:46,760 Speaker 1: usual and asked people on the street, why do you 70 00:03:46,800 --> 00:03:48,040 Speaker 1: think gravity is so weak. 71 00:03:48,320 --> 00:03:50,520 Speaker 2: Here's what a random selection of folks who were willing 72 00:03:50,560 --> 00:03:52,560 Speaker 2: to talk to me on a Tuesday morning had to 73 00:03:52,560 --> 00:03:55,640 Speaker 2: say about gravity. I don't know. I should don't know 74 00:03:55,760 --> 00:03:58,320 Speaker 2: about that, all right. I thought it was a pretty 75 00:03:58,320 --> 00:03:59,280 Speaker 2: strong force, so I don't know. 76 00:04:00,080 --> 00:04:05,520 Speaker 1: But yeah, because it depends on the distance, and it's 77 00:04:05,560 --> 00:04:08,040 Speaker 1: a long range one, so that's why we feel it 78 00:04:08,240 --> 00:04:12,120 Speaker 1: very weak most of the time. Cool, No, okay, I 79 00:04:12,120 --> 00:04:14,400 Speaker 1: have no I'm sorry, it's not very fruitful. 80 00:04:14,960 --> 00:04:18,599 Speaker 2: Hmmm, I have no idea, but I'd be interested in 81 00:04:18,640 --> 00:04:19,880 Speaker 2: finding out why. 82 00:04:20,320 --> 00:04:23,520 Speaker 1: All right, that that was pretty good. Most people weren't 83 00:04:23,600 --> 00:04:25,320 Speaker 1: surprised when you said gravity's weak. 84 00:04:26,200 --> 00:04:28,360 Speaker 2: I don't know. I feel like, of all the questions 85 00:04:28,360 --> 00:04:30,680 Speaker 2: I've asked people, this is the one that flumms them 86 00:04:30,680 --> 00:04:33,159 Speaker 2: the most. You know. People were like, what, I have 87 00:04:33,279 --> 00:04:37,200 Speaker 2: no idea, or they had crazy ideas why gravity must 88 00:04:37,240 --> 00:04:40,000 Speaker 2: be weak. I feel like usually we get one person 89 00:04:40,040 --> 00:04:41,880 Speaker 2: who knows what the answer is or has a good 90 00:04:41,920 --> 00:04:44,520 Speaker 2: clue about what's going on. This time, I feel like 91 00:04:44,600 --> 00:04:47,040 Speaker 2: almost everybody was pretty clueless. I mean, one person said 92 00:04:47,120 --> 00:04:49,760 Speaker 2: I always thought gravity was pretty strong, right, which kind 93 00:04:49,800 --> 00:04:53,800 Speaker 2: of sums up the situation. Right, Gravity's omnipresent in our lives. 94 00:04:53,800 --> 00:04:57,440 Speaker 2: It dominates our experience, and yet it's so weak compared 95 00:04:57,480 --> 00:04:59,640 Speaker 2: to the other really powerful forces we've discovered. 96 00:04:59,800 --> 00:05:02,160 Speaker 1: Well, some people a couple of answers were that it 97 00:05:02,200 --> 00:05:05,719 Speaker 1: had to do with distance, Like gravity gets really weak 98 00:05:05,760 --> 00:05:06,400 Speaker 1: with distance. 99 00:05:06,680 --> 00:05:08,400 Speaker 2: That's right. And the problem there is that all the 100 00:05:08,400 --> 00:05:13,159 Speaker 2: forces get weak with distance, like electromagnetism also falls as 101 00:05:13,520 --> 00:05:16,920 Speaker 2: a distance grows. Right, So all of these forces follow 102 00:05:16,960 --> 00:05:19,280 Speaker 2: this one over R squared rule or are as your 103 00:05:19,320 --> 00:05:21,840 Speaker 2: distance from the things that's giving. 104 00:05:21,640 --> 00:05:23,919 Speaker 1: You the force, right, maybe maybe right. 105 00:05:24,240 --> 00:05:28,000 Speaker 2: Maybe, yeah, mostly we think, And so that can't be 106 00:05:28,040 --> 00:05:29,919 Speaker 2: the answer, right, because all the other forces have that 107 00:05:29,960 --> 00:05:30,520 Speaker 2: same feature. 108 00:05:30,640 --> 00:05:32,080 Speaker 1: So when you say it's the weak is it's not 109 00:05:32,160 --> 00:05:35,719 Speaker 1: that it changes over distances differently than the other forces. 110 00:05:35,839 --> 00:05:38,040 Speaker 2: That's right. So maybe we should talk about what the 111 00:05:38,040 --> 00:05:41,480 Speaker 2: forces are and compare them to each other so folks 112 00:05:41,520 --> 00:05:44,839 Speaker 2: can get understanding of how crazy weak gravity is. Right. 113 00:05:44,880 --> 00:05:48,400 Speaker 1: So, Daniel, what are the forces of nature besides a 114 00:05:48,440 --> 00:05:50,720 Speaker 1: bad movie with Ben Affleck than center bullet. 115 00:05:52,240 --> 00:05:55,240 Speaker 2: Well, I think comedy. Comedy is definitely a force of nature. 116 00:05:55,960 --> 00:05:58,720 Speaker 2: You know, it solves big problems around the world. Now, 117 00:05:59,240 --> 00:06:02,880 Speaker 2: the fundamental force are electromagnetism, right, that's the one that 118 00:06:02,960 --> 00:06:06,640 Speaker 2: controls electricity and magnetism obviously, and is responsible for the 119 00:06:06,680 --> 00:06:11,040 Speaker 2: cool things like light and lightning and all that cool stuff. 120 00:06:11,960 --> 00:06:15,040 Speaker 2: And then there's the weak nuclear force, which is a 121 00:06:15,120 --> 00:06:18,560 Speaker 2: force which is responsible for radioactive decay of a nuclei. Right. 122 00:06:18,600 --> 00:06:21,359 Speaker 2: And the cool thing about electricity and magnetism and the 123 00:06:21,400 --> 00:06:24,080 Speaker 2: weak nuclear force is that we actually have shown that 124 00:06:24,080 --> 00:06:26,880 Speaker 2: there are two sides of the same coin. As a 125 00:06:26,920 --> 00:06:29,359 Speaker 2: particle physicist, we refer to them as one force. We 126 00:06:29,400 --> 00:06:33,159 Speaker 2: call it the electro week. So sort of magnetism lost 127 00:06:33,160 --> 00:06:35,479 Speaker 2: out there in the name merger, right, it should be 128 00:06:35,520 --> 00:06:39,160 Speaker 2: electromagnetic week. But nobody voted to keep magnetism in the 129 00:06:39,279 --> 00:06:41,160 Speaker 2: sort of the name of the partners in the law firm. 130 00:06:41,440 --> 00:06:44,200 Speaker 1: Nobody lobbied for weak electro. 131 00:06:44,320 --> 00:06:50,719 Speaker 2: Or magneto weak force. Yeah. Yeah, again, we are suffering 132 00:06:50,760 --> 00:06:53,520 Speaker 2: the fate of some anonymous committee of scientists that get 133 00:06:53,520 --> 00:06:55,480 Speaker 2: to name these things. Right, Who are these people? 134 00:06:55,680 --> 00:06:58,919 Speaker 1: Probably some grad student, right or some you know, like 135 00:06:59,000 --> 00:07:01,320 Speaker 1: this is really weird, we'll call it this. 136 00:07:01,839 --> 00:07:04,760 Speaker 2: Yeah. So we have electricity and magnetism, which is a 137 00:07:04,800 --> 00:07:06,919 Speaker 2: single force. We have the weak nuclear force, which is 138 00:07:06,960 --> 00:07:09,800 Speaker 2: really should be combined with electricity and magnetism. And then 139 00:07:09,800 --> 00:07:12,040 Speaker 2: there's the strong nuclear force, and this is the one 140 00:07:12,040 --> 00:07:14,640 Speaker 2: that holds the nucleus together. You know, the nucleus is 141 00:07:14,680 --> 00:07:18,760 Speaker 2: of just a bunch of positively charged protons and neutral neutrons. Right, 142 00:07:19,000 --> 00:07:22,080 Speaker 2: it says only positively charged particles in the nucleus. So 143 00:07:22,120 --> 00:07:24,800 Speaker 2: you might think, what it even holds the nucleus together? Right, 144 00:07:24,800 --> 00:07:28,280 Speaker 2: you have all this positively charged stuff should be repelling themselves. Well, 145 00:07:28,320 --> 00:07:31,000 Speaker 2: it's the strong nuclear force, and it does so by 146 00:07:31,000 --> 00:07:34,760 Speaker 2: exchanging these crazy little particles we call gluons, and that 147 00:07:34,880 --> 00:07:37,480 Speaker 2: holds the nucleus together, and it's pretty strong. It's even 148 00:07:37,520 --> 00:07:38,960 Speaker 2: stronger than electromagnetism. 149 00:07:39,080 --> 00:07:41,560 Speaker 1: Well, let's take a step back. So in the universe 150 00:07:41,600 --> 00:07:42,239 Speaker 1: there's stuff. 151 00:07:43,000 --> 00:07:47,240 Speaker 2: There's like, yes, firm that there is stuff in the university. Yes, 152 00:07:47,720 --> 00:07:49,280 Speaker 2: without reservation, there is stuff. 153 00:07:49,320 --> 00:07:52,480 Speaker 1: I'm glad we saw that question. But I mean it's 154 00:07:52,480 --> 00:07:55,480 Speaker 1: like there's stuff that has substance to it, that has 155 00:07:55,720 --> 00:07:58,280 Speaker 1: mass to it, or you know that it sort of exists. 156 00:07:58,320 --> 00:08:01,360 Speaker 1: And then there's also besides the at how these things 157 00:08:01,680 --> 00:08:03,960 Speaker 1: interact with each other, like how they affect each other. 158 00:08:04,120 --> 00:08:07,080 Speaker 2: That's right, there's the matter and then there's the forces, right, 159 00:08:07,080 --> 00:08:09,240 Speaker 2: and the forces affect how they interact with each other. 160 00:08:09,120 --> 00:08:11,760 Speaker 1: And that's pretty much the universe. That's like, it's matter 161 00:08:11,800 --> 00:08:12,360 Speaker 1: and forces. 162 00:08:13,360 --> 00:08:15,040 Speaker 2: Yeah. One way to look at the universe is that 163 00:08:15,080 --> 00:08:18,240 Speaker 2: it's particles, right, or you would say matter and their forces. 164 00:08:18,680 --> 00:08:21,360 Speaker 2: In modern particle physics, we think about one level deeper, 165 00:08:21,400 --> 00:08:24,520 Speaker 2: which is we think of quantum fields, and quantum fields 166 00:08:24,520 --> 00:08:27,600 Speaker 2: are responsible both for matter and for forces. So we 167 00:08:27,600 --> 00:08:30,000 Speaker 2: can talk about that maybe in another podcast. What is 168 00:08:30,040 --> 00:08:32,400 Speaker 2: a quantum field? And how can I get one? You know, 169 00:08:32,440 --> 00:08:35,040 Speaker 2: for lease or rent? What can they do for me? 170 00:08:35,320 --> 00:08:37,319 Speaker 2: But yeah, I think it's fair still to think about 171 00:08:37,600 --> 00:08:39,880 Speaker 2: the universe in terms of particles and forces. 172 00:08:40,679 --> 00:08:56,160 Speaker 1: On that note, let's take a quick break. There are 173 00:08:56,160 --> 00:08:57,720 Speaker 1: only four kinds of forces. 174 00:08:58,040 --> 00:09:01,400 Speaker 2: Yeah, there are four kinds of forces, so electromagnetism, weak 175 00:09:01,480 --> 00:09:05,320 Speaker 2: nuclear force, strong nuclear force, and then of course gravity. Right, 176 00:09:05,320 --> 00:09:07,079 Speaker 2: that's the fourth force that we've discovered. 177 00:09:07,320 --> 00:09:07,600 Speaker 1: Okay. 178 00:09:07,920 --> 00:09:12,520 Speaker 2: The fascinating thing is that different particles feel different forces, right, Like, 179 00:09:12,559 --> 00:09:15,080 Speaker 2: some particles feel this set of forces, some particles feel 180 00:09:15,120 --> 00:09:18,880 Speaker 2: those set of forces. For example, right, particles with electric 181 00:09:19,000 --> 00:09:23,920 Speaker 2: charge feel electromagnetism. Right. The electron, for example, is negatively charged. 182 00:09:24,160 --> 00:09:27,440 Speaker 2: The proton is positively charged. You bring them close together, 183 00:09:27,679 --> 00:09:29,920 Speaker 2: they're gonna pull on each other, They're gonna suck each 184 00:09:29,960 --> 00:09:32,439 Speaker 2: other together, right, because they have opposite charges. We all 185 00:09:32,480 --> 00:09:36,240 Speaker 2: know that. But you bring a neutral particle nearby, it 186 00:09:36,320 --> 00:09:39,360 Speaker 2: just totally ignores it, right, It doesn't feel it at all. Right, Right, 187 00:09:39,440 --> 00:09:42,240 Speaker 2: It's like it's like somebody's walking through a crowd of 188 00:09:42,280 --> 00:09:44,600 Speaker 2: people shouting, but they have headphones on, so they can't 189 00:09:44,600 --> 00:09:46,960 Speaker 2: hear anything, and they're totally oblivious to it. 190 00:09:46,960 --> 00:09:48,440 Speaker 1: It's kind of like how we talked about in a 191 00:09:48,440 --> 00:09:53,200 Speaker 1: previous podcast. They're almost like languages or like social media platforms. 192 00:09:53,240 --> 00:09:55,880 Speaker 1: Like some people are on Twitter, some people are on Facebook, 193 00:09:55,880 --> 00:09:58,000 Speaker 1: but some people are not on this. And so if somebody, 194 00:09:58,200 --> 00:09:59,960 Speaker 1: if you're not on Twitter and somebody sends you a tweet, 195 00:10:00,080 --> 00:10:02,280 Speaker 1: you're not gonna get it. And so it's just different 196 00:10:02,320 --> 00:10:04,200 Speaker 1: ways that particles interact. 197 00:10:03,880 --> 00:10:07,240 Speaker 2: That's right. Gravity is the Google plus of social media, 198 00:10:07,360 --> 00:10:14,560 Speaker 2: right because nobody uses the trends. It's ancient but powerless. Yeah, 199 00:10:14,600 --> 00:10:17,360 Speaker 2: And so different particles feel different forces. And for example, 200 00:10:17,360 --> 00:10:20,800 Speaker 2: an electron, while it feels electromagnetism because it has a 201 00:10:20,840 --> 00:10:23,880 Speaker 2: negative charge, it doesn't feel the strong force at all. 202 00:10:24,200 --> 00:10:26,400 Speaker 2: It will pass right by a bunch of particles that 203 00:10:26,440 --> 00:10:28,600 Speaker 2: are really tugging on each other with a strong force 204 00:10:28,800 --> 00:10:32,319 Speaker 2: and not be affected at all. Whereas quarks, quarks feel 205 00:10:32,440 --> 00:10:35,560 Speaker 2: all the forces. They feel a strong force, which is 206 00:10:35,559 --> 00:10:37,920 Speaker 2: how they get pulled together in the nucleus. Remember, protons 207 00:10:37,960 --> 00:10:41,320 Speaker 2: and neutrons are made of quarks. Quarks feel electromagnetism because 208 00:10:41,360 --> 00:10:44,160 Speaker 2: they have electric charge. They feel the weak force. They 209 00:10:44,200 --> 00:10:46,360 Speaker 2: also feel gravity, of course, because they have masks. So 210 00:10:46,720 --> 00:10:49,840 Speaker 2: quarks get their fingers in everything feel. 211 00:10:49,960 --> 00:10:51,400 Speaker 1: They get the feels for everything. 212 00:10:51,640 --> 00:10:54,319 Speaker 2: They feel everything that's right, They got the strong feels. 213 00:10:55,840 --> 00:10:57,480 Speaker 2: They're really deeply emotional. 214 00:10:57,480 --> 00:10:57,880 Speaker 1: Part of the. 215 00:11:00,000 --> 00:11:01,439 Speaker 2: And the other side of the spectrum you got things 216 00:11:01,480 --> 00:11:04,719 Speaker 2: like neutrinos. The trinos don't have electric charge, so they 217 00:11:04,760 --> 00:11:08,360 Speaker 2: ignore all electricity and magnetism. Right, They don't interact with light. 218 00:11:08,640 --> 00:11:12,960 Speaker 2: They're invisible. They pass right through anything that They ignore 219 00:11:13,000 --> 00:11:16,800 Speaker 2: electromagnetic bonds, so they pass through most materials. They don't 220 00:11:16,800 --> 00:11:19,360 Speaker 2: feel the strong force. The only way they interact is 221 00:11:19,400 --> 00:11:21,840 Speaker 2: with the weak force, and the weak force is pretty weak, 222 00:11:22,000 --> 00:11:24,959 Speaker 2: which is why neutrinos can mostly just pass through matter unaffected. 223 00:11:29,320 --> 00:11:32,080 Speaker 1: So we have four fundamental forces right, And gravity is 224 00:11:32,120 --> 00:11:33,880 Speaker 1: one of these forces, and so when you say that 225 00:11:33,960 --> 00:11:37,640 Speaker 1: gravity is weak, you actually mean it's weak compared to 226 00:11:37,720 --> 00:11:39,520 Speaker 1: these other three forces. 227 00:11:39,280 --> 00:11:42,160 Speaker 2: That's right. And so the ranking is the strong force 228 00:11:42,440 --> 00:11:45,439 Speaker 2: is the strongest, so that one is actually well named. 229 00:11:45,480 --> 00:11:50,120 Speaker 2: Congratulations anonymous group of scientists. Yeah, we should be called 230 00:11:50,120 --> 00:11:52,400 Speaker 2: the as of twenty eighteen, currently known to be the 231 00:11:52,440 --> 00:11:58,320 Speaker 2: strongest force force. After that comes electromagnetism. And you know, 232 00:11:58,400 --> 00:12:00,560 Speaker 2: we know that force is pretty powerful. Stick your finger 233 00:12:00,559 --> 00:12:03,520 Speaker 2: in a socket, you're gonna feel the wrath of electromagnetism. Right, 234 00:12:03,559 --> 00:12:05,640 Speaker 2: It's not an unfamiliar feeling, right. 235 00:12:05,559 --> 00:12:07,680 Speaker 1: Try to stick your finger in anything. You feel it, right, 236 00:12:07,720 --> 00:12:11,440 Speaker 1: because it's Electromagnetism is the force that keeps you from 237 00:12:11,800 --> 00:12:16,760 Speaker 1: basically passing through the table or passing through your car. 238 00:12:16,920 --> 00:12:20,920 Speaker 2: Right, that's right. Because electromagnetism is the basis of chemical bonds, right, 239 00:12:20,960 --> 00:12:22,960 Speaker 2: And chemical bonds are really the thing that form the 240 00:12:23,000 --> 00:12:25,480 Speaker 2: structure of your body. Right. You think of your body 241 00:12:25,520 --> 00:12:27,720 Speaker 2: is like a bunch of particles, but it's held together 242 00:12:27,760 --> 00:12:30,320 Speaker 2: by all these forces. It's like a chain link fence 243 00:12:30,640 --> 00:12:33,439 Speaker 2: binding together these little particles that prevents you from passing 244 00:12:33,520 --> 00:12:36,800 Speaker 2: through something else. Yeah, So we got the strong force, 245 00:12:36,880 --> 00:12:40,640 Speaker 2: and then electromagnetism, and then actually the weak nuclear force. Right, 246 00:12:40,679 --> 00:12:43,560 Speaker 2: this is the force that like powers neutrinos and radioactive decay. 247 00:12:43,800 --> 00:12:48,079 Speaker 2: It's much weaker than electromagnetism and much weaker than the 248 00:12:48,120 --> 00:12:48,760 Speaker 2: strong force. 249 00:12:49,120 --> 00:12:51,280 Speaker 1: Even weaker than the weak is gravity. 250 00:12:51,440 --> 00:12:55,000 Speaker 2: That's right. If you make a list like strong force, electromagnetism, 251 00:12:55,040 --> 00:12:57,040 Speaker 2: in the weak force, then you should leave like one 252 00:12:57,120 --> 00:13:00,840 Speaker 2: hundred blank pages and then you get to grab because 253 00:13:00,840 --> 00:13:03,199 Speaker 2: when we compare these forces, we put things like an 254 00:13:03,200 --> 00:13:06,280 Speaker 2: equal distance apart, and we compare the strength of the forces. 255 00:13:06,520 --> 00:13:11,040 Speaker 2: Gravity is ten to the thirty six times weaker than 256 00:13:11,040 --> 00:13:15,000 Speaker 2: the weak force. That's ten with thirty six zeros in 257 00:13:15,040 --> 00:13:15,520 Speaker 2: front of it. 258 00:13:15,720 --> 00:13:19,360 Speaker 1: But isn't that sort of a matter of units or scale? 259 00:13:19,440 --> 00:13:21,840 Speaker 1: Do you know what I mean? Like, it's much weaker, 260 00:13:21,880 --> 00:13:26,120 Speaker 1: but only if you compare apples to apples, right, orange oranges? 261 00:13:26,200 --> 00:13:28,480 Speaker 2: That's right. But put two protons next to each other, right, 262 00:13:28,760 --> 00:13:31,400 Speaker 2: h two protons have a certain amount of mass and 263 00:13:31,440 --> 00:13:34,000 Speaker 2: a certain amount of electric charge, and the force of 264 00:13:34,040 --> 00:13:36,640 Speaker 2: their charges is going to be much much stronger than 265 00:13:36,640 --> 00:13:38,640 Speaker 2: the force from their masses. Oh I see, So yeah, 266 00:13:38,679 --> 00:13:41,520 Speaker 2: if everything was much much more massive, then there would 267 00:13:41,520 --> 00:13:44,200 Speaker 2: be stronger gravity. But you can compare these things apples 268 00:13:44,200 --> 00:13:46,040 Speaker 2: to apples by comparing them at you know, the same 269 00:13:46,080 --> 00:13:48,560 Speaker 2: distance and the same basic unit of interaction. 270 00:13:48,840 --> 00:13:50,319 Speaker 1: Right, But what if you take an apple put it 271 00:13:50,400 --> 00:13:51,280 Speaker 1: next to another apple? 272 00:13:52,280 --> 00:13:54,360 Speaker 2: Well, I think you can do that experiment. Nothing's going 273 00:13:54,400 --> 00:13:56,719 Speaker 2: to happen because gravity is so weak. Right. You don't 274 00:13:56,760 --> 00:13:59,360 Speaker 2: see two apples like pulling themselves together on the counter, right, 275 00:14:00,040 --> 00:14:02,960 Speaker 2: built in apple collider. You know, the apples are not 276 00:14:03,040 --> 00:14:05,800 Speaker 2: drawn to each other. Gravity is a super weak force, 277 00:14:05,800 --> 00:14:08,200 Speaker 2: and you can see this yourself. Right, you can do 278 00:14:08,240 --> 00:14:12,240 Speaker 2: an experiment where you counter the entire gravitational force of 279 00:14:12,280 --> 00:14:15,720 Speaker 2: an enormous celestial body like the Earth. Right, take a 280 00:14:15,960 --> 00:14:18,880 Speaker 2: small kitchen magnet and use it to hold up a nail, 281 00:14:19,160 --> 00:14:21,600 Speaker 2: and think about what's happening there. Right, you have the 282 00:14:21,680 --> 00:14:25,120 Speaker 2: nail is being pulled down by every single rock in 283 00:14:25,160 --> 00:14:27,760 Speaker 2: the Earth. It's pulling with all of its gravity. But 284 00:14:27,840 --> 00:14:30,600 Speaker 2: a tiny little kitchen magnet totally overcomes that. 285 00:14:31,840 --> 00:14:34,400 Speaker 1: It can lift a nail even though it's pulling. It's 286 00:14:34,440 --> 00:14:37,200 Speaker 1: being pulled down by the whole entire planet Earth. 287 00:14:37,080 --> 00:14:39,480 Speaker 2: Right exactly. And now imagine a magnet the size of 288 00:14:39,520 --> 00:14:42,320 Speaker 2: the Earth, right, I mean that would be that would 289 00:14:42,320 --> 00:14:46,080 Speaker 2: be extraordinarily powerful. And so you have basically like a 290 00:14:46,120 --> 00:14:49,600 Speaker 2: gravitational blob the size of the Earth. Still pretty ineffective 291 00:14:49,680 --> 00:14:51,240 Speaker 2: compared to electromagnetism. 292 00:14:51,400 --> 00:14:56,720 Speaker 1: Mmmm, so it's weak if you sort of compare it 293 00:14:56,760 --> 00:14:59,400 Speaker 1: by object, Like you said, if you take a proton 294 00:14:59,440 --> 00:15:02,600 Speaker 1: and put a nice proton, the force are going to 295 00:15:02,640 --> 00:15:06,200 Speaker 1: feel from electromagnetism is so much bigger than the force 296 00:15:06,200 --> 00:15:08,520 Speaker 1: of gravity. They're going to feel towards each other, the 297 00:15:08,560 --> 00:15:12,440 Speaker 1: same with like two electrons or two quarks and things. 298 00:15:12,680 --> 00:15:14,720 Speaker 1: So in the scale of like the particles that we know, 299 00:15:15,120 --> 00:15:16,359 Speaker 1: it's a really weak. 300 00:15:16,160 --> 00:15:20,320 Speaker 2: Force, that's right, exactly, And yet and yet it seems 301 00:15:20,360 --> 00:15:22,320 Speaker 2: to dominate, right. That's a bit of a puzzle, Like, 302 00:15:22,800 --> 00:15:25,080 Speaker 2: on one hand, it's super duper weak, and we're telling 303 00:15:25,080 --> 00:15:27,200 Speaker 2: you that it hardly counts for anything. On the other hand, 304 00:15:27,520 --> 00:15:29,960 Speaker 2: it's responsible for the structure of the Solar System, man 305 00:15:30,000 --> 00:15:32,360 Speaker 2: for the galaxy, and it's the reason the universe looks 306 00:15:32,360 --> 00:15:34,240 Speaker 2: the way it is, right, right, And so that can 307 00:15:34,280 --> 00:15:36,400 Speaker 2: be confusing to people, Like how do you reconcile those 308 00:15:36,400 --> 00:15:37,400 Speaker 2: two things in your head? 309 00:15:37,560 --> 00:15:40,520 Speaker 1: Yeah, Like, why doesn't the Earth feel an electromagnetic force 310 00:15:40,600 --> 00:15:43,280 Speaker 1: with the Sun, which it would be so much bigger 311 00:15:43,320 --> 00:15:44,960 Speaker 1: than the force of gravity. 312 00:15:45,080 --> 00:15:48,000 Speaker 2: Yeah, well it would be pretty shocking. And that's actually 313 00:15:48,080 --> 00:15:51,360 Speaker 2: the reason is gravity is different from the other forces 314 00:15:51,400 --> 00:15:53,960 Speaker 2: and that it can't be canceled out right, If there 315 00:15:53,960 --> 00:15:57,240 Speaker 2: was some huge electrostatic difference between the Sun and the Earth, 316 00:15:57,360 --> 00:15:59,080 Speaker 2: like a bunch of positive charges there and a bunch 317 00:15:59,120 --> 00:16:02,800 Speaker 2: of negative charges, it would create such an enormous force 318 00:16:03,200 --> 00:16:06,400 Speaker 2: that it would be very quickly balanced. Like that's what 319 00:16:06,560 --> 00:16:10,320 Speaker 2: lightning is. Right. When there's a charge differential between clouds 320 00:16:10,320 --> 00:16:13,720 Speaker 2: and the grounds, it doesn't take that much before those 321 00:16:13,800 --> 00:16:16,880 Speaker 2: charges want to rearrange themselves to a lower energy configuration. 322 00:16:16,960 --> 00:16:18,960 Speaker 2: They rush down to the ground, or they rush up 323 00:16:18,960 --> 00:16:21,080 Speaker 2: to the clouds, or they jump from clouded cloud to 324 00:16:21,120 --> 00:16:24,040 Speaker 2: balance themselves out. Because you have two kinds of charges, 325 00:16:24,040 --> 00:16:26,680 Speaker 2: you have positive and you have negative, so you can 326 00:16:26,840 --> 00:16:30,520 Speaker 2: find an arrangement where basically everybody's happy. It's an equilibrium, right, 327 00:16:30,720 --> 00:16:32,720 Speaker 2: But that's not true for gravity. 328 00:16:32,520 --> 00:16:34,400 Speaker 1: Okay, I get it. So for example, if the Earth 329 00:16:34,640 --> 00:16:38,840 Speaker 1: was every particle on Earth had a positive electromagnetic charge, 330 00:16:39,240 --> 00:16:42,640 Speaker 1: and every particle in the Sun had a negative electromagnetic charge, 331 00:16:43,120 --> 00:16:48,200 Speaker 1: there would be a humongous pull from electromagnetism pulling the 332 00:16:48,240 --> 00:16:49,120 Speaker 1: Earth into the Sun. 333 00:16:49,320 --> 00:16:53,280 Speaker 2: Yeah, we'd be toast pretty quick. Yeah, very long lived experment. 334 00:16:53,400 --> 00:16:56,000 Speaker 1: Yeah, it would be huge. Even the opposite, if we 335 00:16:56,040 --> 00:16:58,240 Speaker 1: were all positive and the Sun was all positive, we 336 00:16:58,240 --> 00:17:01,360 Speaker 1: would get shot out of the sort of system very quickly. 337 00:17:01,440 --> 00:17:03,920 Speaker 2: That's right. And that's why you know, early days of 338 00:17:03,960 --> 00:17:07,359 Speaker 2: the Solar system being formed, you have these gases and 339 00:17:07,400 --> 00:17:11,840 Speaker 2: the gas and dust coalescing, and very rapidly things neutralize, right, 340 00:17:11,840 --> 00:17:15,560 Speaker 2: because anything that feels an electrostatic force to something else 341 00:17:15,800 --> 00:17:18,119 Speaker 2: is going to find the opposite charge and they're going 342 00:17:18,119 --> 00:17:20,080 Speaker 2: to coalesce and they're going to make something neutral. Right. 343 00:17:20,400 --> 00:17:22,840 Speaker 2: That's why most of the things around you are neutral, right, 344 00:17:22,880 --> 00:17:26,560 Speaker 2: Most of the elements are neutral because any deviation from 345 00:17:26,600 --> 00:17:29,600 Speaker 2: neutral results in a powerful force to neutralize it. 346 00:17:29,800 --> 00:17:32,679 Speaker 1: So, thankfully the Earth is made out of both like 347 00:17:32,800 --> 00:17:36,720 Speaker 1: equal amounts of positive and negative particles, right, that's right. 348 00:17:36,960 --> 00:17:40,679 Speaker 1: Thankfully we're sort of balanced electromagnetically, and so even if 349 00:17:40,720 --> 00:17:44,080 Speaker 1: the Sun was all positive, we would look like neutral, 350 00:17:44,200 --> 00:17:45,880 Speaker 1: like a neutral ball to the Sun. 351 00:17:46,160 --> 00:17:49,199 Speaker 2: Yeah, that's right. Where on large scales the Earth is neutral, right, 352 00:17:49,240 --> 00:17:52,000 Speaker 2: I mean there might be some residual positive or negative 353 00:17:52,040 --> 00:17:55,240 Speaker 2: charge depending on the solar wind, et cetera. But basically 354 00:17:55,320 --> 00:17:58,040 Speaker 2: the Earth is neutral, and so the largest force of 355 00:17:58,119 --> 00:18:00,840 Speaker 2: the Earth feels is the gravity from the Sun. Even 356 00:18:00,840 --> 00:18:03,639 Speaker 2: though gravity is super duper weak, right, it doesn't take 357 00:18:03,680 --> 00:18:05,879 Speaker 2: a lot to counteract gravity. But it's the only player 358 00:18:06,000 --> 00:18:08,400 Speaker 2: left because everybody else is sort of pair it up 359 00:18:08,760 --> 00:18:11,600 Speaker 2: and danced off for the night, and gravity's just there left, 360 00:18:11,600 --> 00:18:14,680 Speaker 2: hold in the bag. And gravity can't be balanced, right. 361 00:18:14,800 --> 00:18:17,720 Speaker 2: You feel gravity if you have any mass, right, there's 362 00:18:17,760 --> 00:18:20,679 Speaker 2: only positive masses. There's no such thing as a negative 363 00:18:20,760 --> 00:18:22,560 Speaker 2: mass to give anti gravity. 364 00:18:22,960 --> 00:18:26,320 Speaker 1: Wow, well, let's keep going, but first let's take a 365 00:18:26,400 --> 00:18:42,720 Speaker 1: quick break. Okay, So that's how gravity is so much 366 00:18:42,760 --> 00:18:46,359 Speaker 1: weaker than the other forces. So how's it different than 367 00:18:46,359 --> 00:18:48,160 Speaker 1: the other three forces of nature? 368 00:18:48,320 --> 00:18:51,639 Speaker 2: There's like no end to waste. The gravity is weird, 369 00:18:51,720 --> 00:18:53,639 Speaker 2: you know, there's no end to like the puzzles of 370 00:18:53,680 --> 00:18:55,280 Speaker 2: gravity is fascinating. 371 00:18:54,800 --> 00:18:55,520 Speaker 1: Bottomless pit. 372 00:18:56,560 --> 00:19:00,600 Speaker 2: That's right, it's a black hole of questions. And one 373 00:19:00,680 --> 00:19:03,080 Speaker 2: of my favorites is just that we have no way 374 00:19:03,160 --> 00:19:06,000 Speaker 2: to sort of fit gravity in with the way the 375 00:19:06,080 --> 00:19:08,960 Speaker 2: universe works according to everything else. You know, we talked 376 00:19:08,960 --> 00:19:11,560 Speaker 2: earlier about how we have particles and we have forces 377 00:19:11,640 --> 00:19:15,880 Speaker 2: or quantum fields equivalently, and that's a really successful way 378 00:19:15,880 --> 00:19:17,800 Speaker 2: to describe the universe. You know, we have the Large 379 00:19:17,840 --> 00:19:20,639 Speaker 2: Hadron Collider to explore these things really high energies, and 380 00:19:20,680 --> 00:19:24,199 Speaker 2: we've understood all sorts of things using this theory. But 381 00:19:24,280 --> 00:19:27,520 Speaker 2: that theory is used as quantum mechanics. So the way 382 00:19:27,520 --> 00:19:30,480 Speaker 2: we describe interactions, you know, the way we talk about 383 00:19:30,480 --> 00:19:34,000 Speaker 2: two electrons repelling each other, or the way lightning is 384 00:19:34,040 --> 00:19:37,919 Speaker 2: formed or anything, involves passing quantum particles back and forth. 385 00:19:38,200 --> 00:19:39,720 Speaker 2: And that's just not true for gravity. 386 00:19:40,359 --> 00:19:42,960 Speaker 1: What does that mean? Passing particles back and forth? Like 387 00:19:43,000 --> 00:19:46,920 Speaker 1: when like if I have two magnets and they're attracted 388 00:19:46,960 --> 00:19:49,119 Speaker 1: to each other, they're not. They're not It's not like 389 00:19:49,119 --> 00:19:52,679 Speaker 1: an invisible telekinesis pulling on each other. They're actually swapping 390 00:19:52,720 --> 00:19:54,760 Speaker 1: particles and I can't see that is that kind of 391 00:19:54,800 --> 00:19:55,200 Speaker 1: what do you mean? 392 00:19:55,359 --> 00:19:58,639 Speaker 2: That's exactly what I mean. That the way two things 393 00:19:58,680 --> 00:20:02,280 Speaker 2: interact via some four is by exchanging particles. And so 394 00:20:02,359 --> 00:20:06,360 Speaker 2: for example, electromagnetism, right, is the force behind a magnet, 395 00:20:06,720 --> 00:20:09,240 Speaker 2: and the way electromagnetism works, we think at a sort 396 00:20:09,240 --> 00:20:12,600 Speaker 2: of microscopic particle level is that there's a particle that 397 00:20:12,680 --> 00:20:15,840 Speaker 2: transmits that force, that sends sort of the information back 398 00:20:15,880 --> 00:20:18,560 Speaker 2: and forth between two things that are feeling it. And 399 00:20:18,600 --> 00:20:21,840 Speaker 2: in the case of electromagnetism, that particle is the photon. 400 00:20:22,560 --> 00:20:25,560 Speaker 2: The particle is also a packet of light. So each 401 00:20:25,600 --> 00:20:29,120 Speaker 2: of the quantum forces that we talked about before electromagnetism, 402 00:20:29,359 --> 00:20:31,760 Speaker 2: the weak force and the strong force, each of them 403 00:20:31,800 --> 00:20:34,520 Speaker 2: have a particle we associate with it. And that's not 404 00:20:34,600 --> 00:20:37,320 Speaker 2: just like some name tag we put on and say, hey, 405 00:20:37,320 --> 00:20:39,280 Speaker 2: you get this one, you get this one. We think 406 00:20:39,280 --> 00:20:42,679 Speaker 2: that that's the particle that's responsible for making the force work. 407 00:20:43,080 --> 00:20:45,880 Speaker 2: So when two electrons come near each other, how do 408 00:20:45,880 --> 00:20:48,560 Speaker 2: they repel each other? How does that actually happen? What 409 00:20:48,680 --> 00:20:51,840 Speaker 2: we think that they send photons out right, the electric 410 00:20:51,960 --> 00:20:56,920 Speaker 2: field of a moving electron, Right, an accelerating electron generates photons, 411 00:20:57,160 --> 00:21:01,600 Speaker 2: and those photons interact with the others, and so basically 412 00:21:01,640 --> 00:21:05,480 Speaker 2: the passing messages back and forth using these quantum particles. 413 00:21:05,760 --> 00:21:09,080 Speaker 1: So gravity is weird because we don't know that there 414 00:21:09,160 --> 00:21:12,600 Speaker 1: is a quantum particle being exchanged when two things get 415 00:21:12,600 --> 00:21:14,680 Speaker 1: attracted gravitationally. 416 00:21:14,080 --> 00:21:16,440 Speaker 2: That's right. So we have this great framework. We say, oh, 417 00:21:16,720 --> 00:21:21,960 Speaker 2: maybe all forces are quantum mechanical fields interacting with each other. Right, 418 00:21:22,040 --> 00:21:24,600 Speaker 2: Let's apply that to the electromagnetic field. Yeah it works. 419 00:21:24,760 --> 00:21:26,720 Speaker 2: Let's apply that to the weak force. Yeah it works. 420 00:21:26,840 --> 00:21:29,159 Speaker 2: Let's apply to the strong force. Ooh, cool, it works. 421 00:21:29,320 --> 00:21:31,639 Speaker 2: Maybe this is something deep about the way the universe works. 422 00:21:31,800 --> 00:21:36,000 Speaker 2: Let's apply it to gravity. Uh oh, it doesn't work, right, 423 00:21:36,960 --> 00:21:38,399 Speaker 2: So what does that mean? What does it mean when 424 00:21:38,440 --> 00:21:40,960 Speaker 2: I say it doesn't work? Well? For a theory to work, 425 00:21:41,320 --> 00:21:44,680 Speaker 2: it has to provide predictions for experiments. You have to 426 00:21:44,720 --> 00:21:47,399 Speaker 2: be able to say, okay, theory, what would happen in 427 00:21:47,480 --> 00:21:51,040 Speaker 2: this configuration if I shot a proton and another particle, 428 00:21:51,480 --> 00:21:53,360 Speaker 2: predict what would happen, and then you can go off 429 00:21:53,359 --> 00:21:56,280 Speaker 2: and do the experiments and compare it. Right. Well, when 430 00:21:56,280 --> 00:21:57,840 Speaker 2: you do that for gravity, you try to form a 431 00:21:57,960 --> 00:22:02,160 Speaker 2: quantum theory of gravity, it doesn't work. You get nonsense answers. 432 00:22:02,440 --> 00:22:05,760 Speaker 2: You get answers like infinity right, or things disappear, or 433 00:22:06,040 --> 00:22:09,560 Speaker 2: it's just it doesn't mathematically function. Like, there's no way 434 00:22:09,600 --> 00:22:12,639 Speaker 2: to build a theory of gravity that we've discovered so 435 00:22:12,720 --> 00:22:16,480 Speaker 2: far that works, that actually explains the way these things happen. 436 00:22:17,280 --> 00:22:19,880 Speaker 2: There are a few candidates out there there pretty far 437 00:22:19,920 --> 00:22:23,280 Speaker 2: from being a functional theory of quantum gravity, things like 438 00:22:23,359 --> 00:22:26,359 Speaker 2: loop quantum gravity or string theory. But the basic problem 439 00:22:26,520 --> 00:22:30,239 Speaker 2: is that quantum mechanics and general relativity, which is our 440 00:22:30,240 --> 00:22:32,879 Speaker 2: best theory of gravity, do not play well together, and 441 00:22:32,880 --> 00:22:35,400 Speaker 2: we have no functioning quantum theory of gravity. 442 00:22:37,119 --> 00:22:38,920 Speaker 1: So does that mean that we don't have the right 443 00:22:38,960 --> 00:22:42,760 Speaker 1: theory or is that gravity is just not quantum in nature? 444 00:22:43,000 --> 00:22:45,280 Speaker 2: That's exactly the question we don't know the answer to. 445 00:22:45,560 --> 00:22:47,840 Speaker 2: Right in one hundred years from now, somebody will know 446 00:22:47,880 --> 00:22:49,640 Speaker 2: the answer to that, I hope, and they'll look back 447 00:22:49,680 --> 00:22:51,720 Speaker 2: and they'll wonder, you know, why did those guys see 448 00:22:51,760 --> 00:22:54,399 Speaker 2: the clues? But we don't know. It could be that 449 00:22:54,440 --> 00:22:56,359 Speaker 2: there is a quantum theory of gravity. We're just not 450 00:22:56,400 --> 00:22:58,240 Speaker 2: smart enough to think it up yet, right, Like the 451 00:22:58,320 --> 00:23:01,320 Speaker 2: right person hasn't been born yet to put the math together. 452 00:23:01,440 --> 00:23:03,399 Speaker 2: Or maybe it requires a different kind of math that 453 00:23:03,400 --> 00:23:07,080 Speaker 2: we're using. Right, there's some assumption we're making that's a mistake. 454 00:23:06,920 --> 00:23:09,000 Speaker 1: Or maybe just giving it a wrong name, like maybe 455 00:23:09,000 --> 00:23:17,240 Speaker 1: it should be gravi tunis or gravitinos gravitas. Wait, that's 456 00:23:17,280 --> 00:23:18,200 Speaker 1: taken exactly. 457 00:23:19,119 --> 00:23:21,280 Speaker 2: That's definitely the problem. That's step number one, right. We 458 00:23:21,280 --> 00:23:22,880 Speaker 2: made a mistake in step number one when we could 459 00:23:22,960 --> 00:23:26,359 Speaker 2: define the particle. The other option, of course, is that 460 00:23:26,400 --> 00:23:28,919 Speaker 2: maybe gravity is not a quantum force the way the 461 00:23:28,960 --> 00:23:31,399 Speaker 2: other forces are. Right. The other forces we call them 462 00:23:31,480 --> 00:23:35,040 Speaker 2: quantum forces because they're well described by quantum mechanics. But 463 00:23:35,080 --> 00:23:37,960 Speaker 2: gravity is kind of different. I mean, the current theory 464 00:23:38,000 --> 00:23:41,480 Speaker 2: we have a gravity general relativity. It doesn't like to 465 00:23:41,480 --> 00:23:44,520 Speaker 2: describe gravity as a force, right, describes gravity instead as 466 00:23:44,520 --> 00:23:47,560 Speaker 2: a bending of space. It says that when you have 467 00:23:47,760 --> 00:23:52,800 Speaker 2: mass somewhere in space, space no longer becomes straight, becomes bent. Right, 468 00:23:52,880 --> 00:23:54,920 Speaker 2: So the things move in curves and circles. 469 00:23:55,200 --> 00:23:58,840 Speaker 1: And it's not like an actual just a mathematical nuance 470 00:23:58,920 --> 00:24:01,840 Speaker 1: or a mathematical persons afect of What really confirms it 471 00:24:02,080 --> 00:24:05,600 Speaker 1: is the idea that gravity can affect things that don't 472 00:24:05,640 --> 00:24:07,760 Speaker 1: have mass. Right. That's how we know it's more than 473 00:24:07,880 --> 00:24:10,720 Speaker 1: just a force between things that have mass. It actually 474 00:24:10,760 --> 00:24:14,000 Speaker 1: like affects space for things that don't have mass. 475 00:24:14,080 --> 00:24:16,680 Speaker 2: Right, that's exactly right. So if you shoot a photon 476 00:24:17,320 --> 00:24:21,040 Speaker 2: through space that has mass nearby, the photon will not 477 00:24:21,119 --> 00:24:23,320 Speaker 2: move in what we consider to be a straight line, right, 478 00:24:23,680 --> 00:24:26,920 Speaker 2: it'll find a path through this bent space that involves 479 00:24:26,920 --> 00:24:30,480 Speaker 2: basically curving. And this is what Einstein predicted with his theory, 480 00:24:30,240 --> 00:24:32,680 Speaker 2: and they saw it, you know. And you can see 481 00:24:33,000 --> 00:24:35,960 Speaker 2: in space it's called gravitational lensing. You can see photons 482 00:24:36,000 --> 00:24:39,240 Speaker 2: get bent by heavy objects. And it's because, as you say, 483 00:24:39,280 --> 00:24:41,560 Speaker 2: the heavy objects are bending space itself. 484 00:24:41,880 --> 00:24:44,760 Speaker 1: Right, It's not like gravity is pulling the photon because 485 00:24:44,920 --> 00:24:46,720 Speaker 1: the photon doesn't have any mass. 486 00:24:46,760 --> 00:24:48,960 Speaker 2: Right, that's right, the photon doesn't have any mass. 487 00:24:49,040 --> 00:24:52,359 Speaker 1: Yeah, So that's how it's different. Like gravity seems to 488 00:24:52,400 --> 00:24:56,520 Speaker 1: affect things that don't have sort of its fundamental property, 489 00:24:56,640 --> 00:25:00,360 Speaker 1: you know, like electromanicnetic forces can affect something that does 490 00:25:00,400 --> 00:25:01,800 Speaker 1: not have an electric charge. 491 00:25:01,840 --> 00:25:02,240 Speaker 2: That's true. 492 00:25:02,280 --> 00:25:04,320 Speaker 1: Gravity can affect thing everything else, right. 493 00:25:04,720 --> 00:25:06,320 Speaker 2: Yeah, that's a pretty deep insight there. 494 00:25:06,760 --> 00:25:10,520 Speaker 1: Well, not bad for a cartoonist, not at all. 495 00:25:10,760 --> 00:25:13,320 Speaker 2: Yeah, that's a fascinating way to think about it. I 496 00:25:13,320 --> 00:25:16,960 Speaker 2: think that's totally correct. Yeah. And so if gravity is 497 00:25:17,040 --> 00:25:19,280 Speaker 2: instead of being a force, if it's a way we 498 00:25:19,480 --> 00:25:22,600 Speaker 2: change the shape of space itself, then maybe that's why 499 00:25:22,640 --> 00:25:25,000 Speaker 2: we don't have a quantum theory of it. Right, And 500 00:25:25,320 --> 00:25:28,960 Speaker 2: that's amazing and it's fantastic and it's exciting. And another 501 00:25:29,000 --> 00:25:30,920 Speaker 2: reason why we have a hard time bringing these two 502 00:25:30,920 --> 00:25:34,680 Speaker 2: things together is that quantum mechanics, the theory we've developed 503 00:25:34,960 --> 00:25:38,360 Speaker 2: only works so far in flat space. That is, if 504 00:25:38,400 --> 00:25:41,280 Speaker 2: there's really heavy stuff nearby, we don't know how to 505 00:25:41,280 --> 00:25:44,480 Speaker 2: do those quantum calculations. We can basically only do quantum 506 00:25:44,520 --> 00:25:47,360 Speaker 2: mechanics in places where there isn't really strong gravity. 507 00:25:47,680 --> 00:25:52,040 Speaker 1: So wait, it's a quantum physics doesn't work in reality basically? 508 00:25:52,359 --> 00:25:54,960 Speaker 1: Is that what you're saying, Like, it doesn't work in 509 00:25:56,040 --> 00:25:57,639 Speaker 1: the space that we actually live. 510 00:25:57,520 --> 00:26:00,399 Speaker 2: In, Well, it works basically everywhere except for close to 511 00:26:00,440 --> 00:26:04,360 Speaker 2: black holes. Mmm, right, you need basically a black hole. 512 00:26:04,400 --> 00:26:07,320 Speaker 2: I have enough gravity to break down quantum mechanics because 513 00:26:07,320 --> 00:26:10,480 Speaker 2: it's when when space gets really distorted that you start 514 00:26:10,560 --> 00:26:13,520 Speaker 2: to see the effects of gravity on space, and then 515 00:26:13,560 --> 00:26:16,359 Speaker 2: it becomes comparable to the strength of other stuff, and 516 00:26:16,400 --> 00:26:19,520 Speaker 2: that's when that's when quantum mechanics breaks down. Yeah, quantum 517 00:26:19,680 --> 00:26:22,399 Speaker 2: quantum field theory works basically what we call flat space, 518 00:26:22,440 --> 00:26:24,560 Speaker 2: whereas gravity bends space. 519 00:26:24,800 --> 00:26:32,240 Speaker 1: Wow, so earlier when we categorize gravity as part of 520 00:26:32,240 --> 00:26:35,320 Speaker 1: these four fundamental forces, maybe that's just the wrong approach. 521 00:26:35,400 --> 00:26:36,639 Speaker 1: Maybe you know, do you know what I mean? Like, 522 00:26:36,680 --> 00:26:41,160 Speaker 1: maybe we shouldn't be categorizing these four things as one 523 00:26:41,240 --> 00:26:43,240 Speaker 1: category of quote forces. 524 00:26:44,119 --> 00:26:45,679 Speaker 2: That's right. It could be that it could be that 525 00:26:45,720 --> 00:26:48,520 Speaker 2: there is no quantum theory of gravity as a fundamental 526 00:26:48,520 --> 00:26:50,800 Speaker 2: force because it isn't one. Yeah, and it's just a 527 00:26:50,840 --> 00:26:54,959 Speaker 2: feature of space, right, Absolutely, that's one possible explanation. But 528 00:26:55,000 --> 00:26:57,800 Speaker 2: then we still need a way to make quantum mechanics 529 00:26:57,840 --> 00:27:00,119 Speaker 2: work in bend space, right, And we still need to 530 00:27:00,200 --> 00:27:04,320 Speaker 2: understand how to make our theory of general relativity play 531 00:27:04,400 --> 00:27:07,320 Speaker 2: well with quantum mechanics, because we think quantum mechanics describes 532 00:27:07,400 --> 00:27:10,920 Speaker 2: the universe, right, and general relativity is not a quantized theory. 533 00:27:10,920 --> 00:27:14,679 Speaker 2: It's it's continuous, right. It treats space and everything as 534 00:27:14,720 --> 00:27:18,520 Speaker 2: if it's infinitely divisible. Right, it's not a quantum theory 535 00:27:18,520 --> 00:27:20,359 Speaker 2: at all. In fact that it came about before quantum 536 00:27:20,359 --> 00:27:23,200 Speaker 2: mechanics was even invented. Right. And so while the basic 537 00:27:23,320 --> 00:27:25,800 Speaker 2: tenets of it and how it distorted space are probably correct, 538 00:27:25,800 --> 00:27:29,439 Speaker 2: i mean, been verified to zillion degrees of accuracy, it 539 00:27:29,480 --> 00:27:32,320 Speaker 2: doesn't feel like it can be a fundamental description of 540 00:27:32,400 --> 00:27:34,320 Speaker 2: nature because it's not quantum mechanical. 541 00:27:34,640 --> 00:27:36,680 Speaker 1: So like we want to call it a force because 542 00:27:36,720 --> 00:27:39,600 Speaker 1: it seems to move things like all the other forces, 543 00:27:40,080 --> 00:27:42,119 Speaker 1: but it's maybe it's not a force. Maybe it's just 544 00:27:42,240 --> 00:27:45,360 Speaker 1: kind of like some other weird property of space. 545 00:27:45,760 --> 00:27:48,000 Speaker 2: Yeah, exactly. You know, maybe we've been trying to put 546 00:27:48,040 --> 00:27:50,639 Speaker 2: a round peg into a square hole all these years. 547 00:27:52,280 --> 00:27:54,000 Speaker 1: A gravity peg and a quantum hole. 548 00:27:54,960 --> 00:27:57,560 Speaker 2: That's right, that's right. And there are other ways that 549 00:27:57,560 --> 00:27:59,560 Speaker 2: people are trying to solve this problem. Like one way 550 00:27:59,680 --> 00:28:02,399 Speaker 2: is things that maybe gravity is a fundamental force, but 551 00:28:02,440 --> 00:28:04,800 Speaker 2: it just works a little bit differently from the other forces. 552 00:28:05,119 --> 00:28:07,919 Speaker 2: For example, people think about how the universe might have 553 00:28:08,000 --> 00:28:11,200 Speaker 2: additional spatial dimensions, you know, like instead of just being 554 00:28:11,200 --> 00:28:13,680 Speaker 2: able to move in three directions, maybe there's like four 555 00:28:13,720 --> 00:28:16,359 Speaker 2: or five six dimensions that you can move in. And 556 00:28:16,400 --> 00:28:18,160 Speaker 2: folks who are interested in that should listen to our 557 00:28:18,400 --> 00:28:19,879 Speaker 2: podcast on extra dimensions. 558 00:28:20,160 --> 00:28:22,240 Speaker 1: No, yeah, we did a whole episode on extra dimensions, 559 00:28:22,240 --> 00:28:24,240 Speaker 1: but we didn't sort of get into this particular topic. 560 00:28:24,880 --> 00:28:29,280 Speaker 1: So tell us how extra dimensions might explain why gravity 561 00:28:29,359 --> 00:28:29,919 Speaker 1: is so weak. 562 00:28:30,240 --> 00:28:32,960 Speaker 2: Yeah, The idea is that maybe gravity isn't so weak. 563 00:28:33,040 --> 00:28:36,200 Speaker 2: Maybe gravity is just as strong as all the other forces. 564 00:28:36,760 --> 00:28:40,080 Speaker 2: But if there's a whole other set of dimensions out there. 565 00:28:40,160 --> 00:28:43,960 Speaker 2: There's ways directions that think can move. It might be 566 00:28:44,160 --> 00:28:47,280 Speaker 2: that gravity is the only thing that feels those dimensions, right. 567 00:28:47,280 --> 00:28:50,360 Speaker 2: It might be that those dimensions are invisible to electromagnetism 568 00:28:50,680 --> 00:28:52,760 Speaker 2: and to the weak force into the strong force, but 569 00:28:52,960 --> 00:28:56,640 Speaker 2: visible to gravity. And what that means is that gravity 570 00:28:56,720 --> 00:29:00,200 Speaker 2: might be basically leaking out into those other dimensions. You know, 571 00:29:00,240 --> 00:29:03,040 Speaker 2: we talked about how the farther away you get from something, 572 00:29:03,040 --> 00:29:06,160 Speaker 2: the weaker the forces. So like Mercury feels the force 573 00:29:06,200 --> 00:29:09,400 Speaker 2: of the Sun's gravity much more strongly than Pluto does. Right, 574 00:29:09,640 --> 00:29:11,360 Speaker 2: irrelevant of whether or not you call it a planet, 575 00:29:11,480 --> 00:29:14,160 Speaker 2: it doesn't feel gravity very strongly. And that's because it's 576 00:29:14,200 --> 00:29:15,920 Speaker 2: further from the Sun, right. I mean that goes like 577 00:29:15,960 --> 00:29:18,960 Speaker 2: one over are squared or are as the distance it's 578 00:29:19,000 --> 00:29:21,800 Speaker 2: one of our squared because we have three dimensions. If 579 00:29:21,800 --> 00:29:25,520 Speaker 2: we had six dimensions, it would be one over R five, right, 580 00:29:25,600 --> 00:29:29,400 Speaker 2: which falls much more rapidly. So if there are additional 581 00:29:29,400 --> 00:29:33,760 Speaker 2: dimensions out there, okay, and only gravity feels them, then 582 00:29:33,840 --> 00:29:37,680 Speaker 2: that might be the reason why gravitational force falls so quickly. 583 00:29:37,960 --> 00:29:40,600 Speaker 2: Maybe gravity's actually just as strong as everything else. When 584 00:29:40,600 --> 00:29:43,920 Speaker 2: you get really really close. But then these extra dimensions exist, 585 00:29:43,960 --> 00:29:46,720 Speaker 2: and most of gravity leaks out into those other dimensions. 586 00:29:47,040 --> 00:29:50,480 Speaker 1: Oh, sort of like between you and me, there's not 587 00:29:50,600 --> 00:29:53,440 Speaker 1: just the three dimensions between you and me. May there 588 00:29:53,440 --> 00:29:56,960 Speaker 1: are other secret hidden spaces kind of between you and me? 589 00:29:57,320 --> 00:29:59,640 Speaker 1: Are these other dimensions exactly? 590 00:29:59,640 --> 00:30:02,200 Speaker 2: Other ways for gravity to spread out, all right? 591 00:30:02,320 --> 00:30:04,280 Speaker 1: And so gravity would be like just as strong as 592 00:30:04,400 --> 00:30:07,440 Speaker 1: all the other forces, but it's just fleshing its muscles 593 00:30:07,680 --> 00:30:11,760 Speaker 1: in these other spaces that we can't see or feel exactly. 594 00:30:11,800 --> 00:30:13,480 Speaker 2: It's like, you know, if somebody's at the center of 595 00:30:13,520 --> 00:30:16,120 Speaker 2: a crowd and they let go a really stinky far right. 596 00:30:16,200 --> 00:30:18,520 Speaker 2: The people next to them they smell it strongly, and 597 00:30:18,520 --> 00:30:21,040 Speaker 2: the people further away they smell it much more weakly, 598 00:30:21,080 --> 00:30:22,880 Speaker 2: and people outside don't smell it at all. 599 00:30:22,920 --> 00:30:26,080 Speaker 1: All right, now, imagine the farts really suddenly. But let's 600 00:30:26,160 --> 00:30:27,120 Speaker 1: let's let's go with it. 601 00:30:27,200 --> 00:30:29,600 Speaker 2: Hey, I'm trying to make this successible. You know, this 602 00:30:29,640 --> 00:30:30,840 Speaker 2: is something everybody canna. 603 00:30:30,600 --> 00:30:32,840 Speaker 1: Appreciate it trying to make way I get it cut it. 604 00:30:35,120 --> 00:30:37,200 Speaker 2: But if there was somewhere else for that far to go, 605 00:30:37,320 --> 00:30:39,720 Speaker 2: you know, if it could move not just sideways, but 606 00:30:39,800 --> 00:30:42,040 Speaker 2: also could float up right so you had a really 607 00:30:42,080 --> 00:30:44,959 Speaker 2: tall room in the far floated up, then people wouldn't 608 00:30:44,960 --> 00:30:46,720 Speaker 2: feel it as much because most of them far would 609 00:30:46,720 --> 00:30:50,400 Speaker 2: dissipate into the upper corners of the room. And so 610 00:30:50,520 --> 00:30:52,320 Speaker 2: gravity might be the same way. It might be that 611 00:30:52,520 --> 00:30:55,160 Speaker 2: you know, for the first millimeters, so the first centimeters, 612 00:30:55,240 --> 00:30:59,280 Speaker 2: so gravity gets very weak, very quickly. It falls off 613 00:30:59,360 --> 00:31:02,520 Speaker 2: really rapidly, and that then you know, at normal distances 614 00:31:02,520 --> 00:31:04,840 Speaker 2: like a meter or ten meters or whatever, you don't 615 00:31:04,840 --> 00:31:07,640 Speaker 2: feel those other dimensions anymore because the other other dimensions 616 00:31:07,720 --> 00:31:10,520 Speaker 2: only activate it really really short distances. This is the 617 00:31:10,520 --> 00:31:12,400 Speaker 2: theory people came up with, and we don't know if 618 00:31:12,440 --> 00:31:14,520 Speaker 2: it's real. You know, we've tested it so far. It 619 00:31:14,520 --> 00:31:18,960 Speaker 2: seems like gravity works the same way for galactic scales 620 00:31:19,040 --> 00:31:21,760 Speaker 2: and for Earth scales, and for microscopic scales. It seems 621 00:31:21,760 --> 00:31:24,120 Speaker 2: to always fall off at the same rate as a 622 00:31:24,160 --> 00:31:26,760 Speaker 2: function of distance. So nobody's ever seen any evidence of 623 00:31:26,800 --> 00:31:29,560 Speaker 2: these extra dimensions. But it's a fascinating theory and it's 624 00:31:29,560 --> 00:31:31,160 Speaker 2: a you know, it's one that would give kind of 625 00:31:31,160 --> 00:31:34,560 Speaker 2: a natural explanation for why gravity would fall off so 626 00:31:34,680 --> 00:31:37,120 Speaker 2: quickly and why gravity is so weak. It wouldn't explain 627 00:31:37,160 --> 00:31:38,240 Speaker 2: all these other things, But. 628 00:31:38,640 --> 00:31:40,560 Speaker 1: In fact people sort of try to use gravity to 629 00:31:40,680 --> 00:31:42,720 Speaker 1: see if there are other dimensions. 630 00:31:42,320 --> 00:31:44,680 Speaker 2: Right, Yeah, that's right. It would be a really cool clue, 631 00:31:44,760 --> 00:31:48,280 Speaker 2: right if And that's a fascinating way that science has done. 632 00:31:48,360 --> 00:31:50,640 Speaker 2: You know, you try to look at everything around you 633 00:31:50,680 --> 00:31:52,760 Speaker 2: and see if you can fit it all into one framework, 634 00:31:53,000 --> 00:31:55,480 Speaker 2: like can I use this one set of ideas to 635 00:31:55,520 --> 00:32:00,560 Speaker 2: describe everything? Right? Can irge edit onto one part of concepts? Yeah, 636 00:32:00,880 --> 00:32:03,800 Speaker 2: that's right. In my fart theory of you in the universe. 637 00:32:09,000 --> 00:32:11,040 Speaker 2: The best possible way I think to unravel this is 638 00:32:11,080 --> 00:32:14,080 Speaker 2: to actually go visit a black hole, because quantum mechanics 639 00:32:14,080 --> 00:32:17,280 Speaker 2: and general relativity tell you very different things about what's 640 00:32:17,320 --> 00:32:20,280 Speaker 2: happening inside a black hole. Right, As we said before, 641 00:32:20,720 --> 00:32:23,440 Speaker 2: general relativity tells you it's an infinite tesimal dot of 642 00:32:23,720 --> 00:32:27,240 Speaker 2: almost infinite density. Quantum mechanics says, you know, the universe 643 00:32:27,320 --> 00:32:29,840 Speaker 2: is quantized first of all, so you can't have infinite 644 00:32:29,840 --> 00:32:33,200 Speaker 2: testimal dots. And also there's sort of a minimum size 645 00:32:33,200 --> 00:32:35,680 Speaker 2: to stuff, right, and you can't have all that stuff 646 00:32:35,760 --> 00:32:38,760 Speaker 2: compressed in such a tiny little area. And so if 647 00:32:38,760 --> 00:32:40,560 Speaker 2: you could see inside a black hole, you would learn 648 00:32:40,600 --> 00:32:41,760 Speaker 2: a lot about gravity. 649 00:32:42,040 --> 00:32:43,600 Speaker 1: So what would be the plan. You would go into 650 00:32:43,600 --> 00:32:46,480 Speaker 1: a black hole. You would observe and discover how the 651 00:32:46,560 --> 00:32:49,480 Speaker 1: universe works, and then and then you'd be stuck there. 652 00:32:49,800 --> 00:32:51,360 Speaker 2: That's right. They would have to send you a Nobel 653 00:32:51,400 --> 00:32:53,560 Speaker 2: Prize into the black hole after that, which is assume 654 00:32:53,600 --> 00:32:57,080 Speaker 2: you'd figure it out and pause the Nobel Prize into 655 00:32:57,080 --> 00:33:01,320 Speaker 2: space into the black hole. Anybod who's listening, please do 656 00:33:01,440 --> 00:33:03,680 Speaker 2: not go into a black hole. Please please do not 657 00:33:03,720 --> 00:33:05,400 Speaker 2: go into a black hole. But you know, we don't 658 00:33:05,400 --> 00:33:07,520 Speaker 2: need to visit black holes. We could try to create 659 00:33:07,520 --> 00:33:08,400 Speaker 2: them here on Earth. 660 00:33:08,560 --> 00:33:10,120 Speaker 1: That sounds like a great idea. 661 00:33:10,480 --> 00:33:12,360 Speaker 2: Yeah, doesn't that sound like a great idea? I mean 662 00:33:12,640 --> 00:33:17,200 Speaker 2: I'm excited make it. So, Yeah, let's create a black 663 00:33:17,200 --> 00:33:20,880 Speaker 2: hole and study it. Right, if gravity gets really really 664 00:33:20,920 --> 00:33:23,440 Speaker 2: powerful when you get to really short distances because of 665 00:33:23,480 --> 00:33:25,720 Speaker 2: this extra dimension theory, then it might be that if 666 00:33:25,760 --> 00:33:28,080 Speaker 2: you shoot two protons together really really hard and they 667 00:33:28,120 --> 00:33:29,920 Speaker 2: get really really close to each other, that you can 668 00:33:29,960 --> 00:33:33,840 Speaker 2: create a super duper mini extra cute, little fuzzy black hole. Right, 669 00:33:34,040 --> 00:33:35,800 Speaker 2: I'm trying to make it sound like a cozy thing. 670 00:33:36,640 --> 00:33:40,040 Speaker 1: Yeah, you're trying to sell it, right. 671 00:33:42,840 --> 00:33:46,120 Speaker 2: And so before we turned on the large Hadron collide. 672 00:33:46,120 --> 00:33:48,800 Speaker 2: About ten years ago, people thought maybe by smashing these 673 00:33:48,800 --> 00:33:51,200 Speaker 2: protons together we could actually create black holes and we 674 00:33:51,200 --> 00:33:54,240 Speaker 2: could study them. We can reveal the deep secrets of gravity. 675 00:33:54,360 --> 00:33:58,280 Speaker 1: Right, hmmm, So then the idea would be to try 676 00:33:58,280 --> 00:34:00,280 Speaker 1: to make them at the Large Headron Collider and just 677 00:34:00,360 --> 00:34:02,880 Speaker 1: can of see what happens, Like, does it tell us 678 00:34:02,920 --> 00:34:05,920 Speaker 1: something about gravity or quantum physics at the same. 679 00:34:05,760 --> 00:34:09,080 Speaker 2: Time, Yeah, exactly. By seeing how often they're made and 680 00:34:09,120 --> 00:34:11,480 Speaker 2: how strong they are and what they turned into, whether 681 00:34:11,480 --> 00:34:14,799 Speaker 2: they decay, we could understand something about the way black 682 00:34:14,840 --> 00:34:17,360 Speaker 2: holes work, and that would have been really powerful. But 683 00:34:17,440 --> 00:34:21,080 Speaker 2: unfortunately or fortunately, depending on how you feel above black holes. 684 00:34:21,239 --> 00:34:23,160 Speaker 2: We haven't made any black holes at the Large Hadron 685 00:34:23,200 --> 00:34:24,719 Speaker 2: Collider that we've discovered. 686 00:34:25,440 --> 00:34:27,680 Speaker 1: But maybe isn't it true that maybe you've made them 687 00:34:27,680 --> 00:34:28,480 Speaker 1: but they evaporate. 688 00:34:28,840 --> 00:34:31,080 Speaker 2: Yes, these black holes would be very short lived, but 689 00:34:31,160 --> 00:34:33,080 Speaker 2: you know, everything we make at the Large Hadron Collider 690 00:34:33,120 --> 00:34:34,920 Speaker 2: is really short lived. These things last for like ten 691 00:34:34,960 --> 00:34:36,920 Speaker 2: to the negative thirty seconds or ten to the negative 692 00:34:36,920 --> 00:34:39,680 Speaker 2: twenty three seconds. We're pretty good at seeing short lived 693 00:34:39,680 --> 00:34:42,440 Speaker 2: stuff because it usually blows up into other things, and 694 00:34:42,480 --> 00:34:45,000 Speaker 2: a black hole would have a really unusual signature in 695 00:34:45,040 --> 00:34:47,200 Speaker 2: our detector, it would be pretty clear to see if 696 00:34:47,200 --> 00:34:47,960 Speaker 2: we had made them. 697 00:34:48,080 --> 00:34:51,520 Speaker 1: Okay, but short of going into a black hole or 698 00:34:51,719 --> 00:34:56,040 Speaker 1: detecting farts in extra dimensions, we may not know in 699 00:34:56,080 --> 00:34:59,040 Speaker 1: the near future what what makes gravity so different? 700 00:34:59,160 --> 00:35:01,840 Speaker 2: That's right, take some work. I mean. The other direction, 701 00:35:02,160 --> 00:35:04,600 Speaker 2: is theoretical, is to build up a theory of quantum 702 00:35:04,640 --> 00:35:06,920 Speaker 2: gravity sort of from the bottom up. 703 00:35:06,840 --> 00:35:09,759 Speaker 1: Like start from the beauty of math and physics, and 704 00:35:09,800 --> 00:35:13,520 Speaker 1: then try to build it up to our level exactly. 705 00:35:13,520 --> 00:35:15,719 Speaker 2: And that's that's a wonderful way to do, is to say, like, 706 00:35:15,960 --> 00:35:18,800 Speaker 2: maybe the universe works in this way its most basic 707 00:35:18,880 --> 00:35:21,600 Speaker 2: fundamental nature, and build it up from there and see 708 00:35:21,640 --> 00:35:24,480 Speaker 2: if you can describe the universe that we see around us. Wow. 709 00:35:25,440 --> 00:35:29,759 Speaker 1: All right, well, that's pretty shocking to think gravity is 710 00:35:29,840 --> 00:35:32,000 Speaker 1: such a place, such a big role in our lives, 711 00:35:32,000 --> 00:35:36,080 Speaker 1: and yet it's like the weakling in the universe, right. 712 00:35:36,320 --> 00:35:40,160 Speaker 1: It's like, imagine if if gravity was stronger, life would 713 00:35:40,200 --> 00:35:42,360 Speaker 1: be a lot more chaotic, right and crazy? 714 00:35:42,600 --> 00:35:44,759 Speaker 2: Yeah, exactly. We would be closer to the Sun and 715 00:35:44,880 --> 00:35:47,680 Speaker 2: everything would feel more intense. It's fascinating to me that 716 00:35:47,760 --> 00:35:50,959 Speaker 2: gravity has been a mystery to physics for hundreds of years. 717 00:35:50,960 --> 00:35:53,320 Speaker 2: I mean it was the focus of Isaac Newton's studies, 718 00:35:53,360 --> 00:35:56,120 Speaker 2: you know, like hundreds of years ago, people working on gravity. 719 00:35:56,160 --> 00:35:59,200 Speaker 2: And still today, even though we've made so much progress 720 00:35:59,200 --> 00:36:01,680 Speaker 2: in terms of gravity, we still have so much, so 721 00:36:01,760 --> 00:36:04,040 Speaker 2: many basic questions about it that we don't know the 722 00:36:04,080 --> 00:36:06,360 Speaker 2: answers to, not even the really beginning of how to 723 00:36:06,400 --> 00:36:09,439 Speaker 2: answer them to meet. That's fascinating. Gravity such a rich 724 00:36:09,560 --> 00:36:12,239 Speaker 2: source of mystery for physics and for everybody. 725 00:36:12,640 --> 00:36:15,400 Speaker 1: Wow, all right, cool, I think it's maybe time to 726 00:36:16,160 --> 00:36:18,319 Speaker 1: push down this question. Thanks for joining us. 727 00:36:26,640 --> 00:36:28,960 Speaker 2: If you still have a question after listening to all 728 00:36:28,960 --> 00:36:32,200 Speaker 2: these explanations, please drop us a line. We'd love to 729 00:36:32,239 --> 00:36:34,680 Speaker 2: hear from you. You can find us at Facebook, Twitter, 730 00:36:34,719 --> 00:36:38,400 Speaker 2: and Instagram at Daniel and Jorge that's one word, or 731 00:36:38,520 --> 00:36:50,759 Speaker 2: email us at Feedback at Daniel Andorge dot com.