1 00:00:07,160 --> 00:00:10,200 Speaker 1: I just think it's fascinating that it's such a fundamental 2 00:00:10,720 --> 00:00:14,440 Speaker 1: force in the universe, right Like, it's it's basically the 3 00:00:14,480 --> 00:00:19,520 Speaker 1: thing that builds galaxies and keeps planets moving right and 4 00:00:19,640 --> 00:00:23,000 Speaker 1: gets structured to the entire cosmos. That's right on the 5 00:00:23,079 --> 00:00:26,880 Speaker 1: largest scales, actually the most important force. It's the reason 6 00:00:26,960 --> 00:00:29,520 Speaker 1: why things look the way they do, the reason why 7 00:00:29,800 --> 00:00:32,559 Speaker 1: our planet is around, it's the reason why we're on 8 00:00:32,640 --> 00:00:36,239 Speaker 1: the planet. It's pretty important, and yet we don't know 9 00:00:36,760 --> 00:00:39,240 Speaker 1: a lot about it, right, Like, there's some really deep 10 00:00:39,560 --> 00:00:42,760 Speaker 1: and strange mysteries about it. On one hand, we have 11 00:00:42,840 --> 00:00:45,360 Speaker 1: a theory which works really really well. On the other hand, 12 00:00:45,400 --> 00:00:48,040 Speaker 1: we have questions about it, but to seem really really basic. 13 00:00:48,520 --> 00:00:50,879 Speaker 1: And not only that, it's it's very different than all 14 00:00:50,880 --> 00:00:54,240 Speaker 1: the other forces of nature. That's right, one of these 15 00:00:54,280 --> 00:01:15,520 Speaker 1: things is not like the other ones. Ye hi am more. 16 00:01:15,640 --> 00:01:18,920 Speaker 1: I'm a cartoonist and I'm Daniel, I'm a particle physicist. 17 00:01:19,160 --> 00:01:22,440 Speaker 1: And this is our podcast Daniel and Joe explained the universe, 18 00:01:22,600 --> 00:01:25,320 Speaker 1: in which our cartoonist and physicists try to figure out 19 00:01:25,360 --> 00:01:29,960 Speaker 1: how to make the universe understandable to anybody. Yeah, and 20 00:01:30,000 --> 00:01:34,360 Speaker 1: today on the podcast we are examining a very heavy topic, 21 00:01:39,440 --> 00:01:46,959 Speaker 1: gravity and specifically why is gravity so weak and strange. Gravity, 22 00:01:47,120 --> 00:01:50,200 Speaker 1: as we said earlier, is something which controls the structure 23 00:01:50,280 --> 00:01:52,520 Speaker 1: of the universe. I mean, the reason the Solar system 24 00:01:52,560 --> 00:01:54,920 Speaker 1: looks the way it does is because of gravity. The 25 00:01:54,960 --> 00:01:57,560 Speaker 1: reason the Earth is round is because of gravity. The 26 00:01:57,600 --> 00:02:00,600 Speaker 1: reason we have galaxies is because of gravity. The reason 27 00:02:00,640 --> 00:02:02,920 Speaker 1: we weighed so much, it's it's because of gravity. Right, 28 00:02:02,960 --> 00:02:07,640 Speaker 1: it's not my belt, No, that's because of late night 29 00:02:07,720 --> 00:02:13,200 Speaker 1: cake eating. Um. But it's such a fundamental force of nature. Rights, Like, 30 00:02:13,280 --> 00:02:16,440 Speaker 1: it's present in our everyday live We spend a lot 31 00:02:16,480 --> 00:02:20,480 Speaker 1: of time thinking about gravity, right, how not to fall down, 32 00:02:20,760 --> 00:02:23,639 Speaker 1: how not drop things, how to go up buildings, how 33 00:02:23,680 --> 00:02:26,120 Speaker 1: to go down buildings? Right, that's right. It seems like 34 00:02:26,200 --> 00:02:27,799 Speaker 1: one of the most important forces. I mean, if you 35 00:02:27,880 --> 00:02:30,840 Speaker 1: ask people, you know, to name a force or what 36 00:02:30,919 --> 00:02:33,200 Speaker 1: kind of forces the experience in their life, gravity is 37 00:02:33,200 --> 00:02:35,919 Speaker 1: the one that's present in their lives. Right, you're climbing upstairs, 38 00:02:35,919 --> 00:02:38,960 Speaker 1: you're fighting gravity. Trip, you fall down, you're feeling gravity. 39 00:02:39,160 --> 00:02:41,720 Speaker 1: You look around you. The shape of things is controlled 40 00:02:41,720 --> 00:02:46,000 Speaker 1: by gravity, and that's why it's particularly strange that gravity 41 00:02:46,120 --> 00:02:49,200 Speaker 1: is the weakest force of all the forces we've discovered, 42 00:02:49,440 --> 00:02:52,760 Speaker 1: it's by far the weakest. Yeah, it's really strange to 43 00:02:53,120 --> 00:02:55,680 Speaker 1: hear you say that, Like, how can gravity be weak? 44 00:02:56,000 --> 00:02:58,600 Speaker 1: Like you know, like it's it's keeping the whole Earth together, 45 00:02:58,680 --> 00:03:02,200 Speaker 1: it's making the entire higher planet swing around, going to 46 00:03:02,240 --> 00:03:05,359 Speaker 1: circle basically, right. Without gravity, we would just shoot off 47 00:03:05,360 --> 00:03:08,760 Speaker 1: into space. That's right. It's a really strange situation. And 48 00:03:08,800 --> 00:03:11,160 Speaker 1: there's other things about gravity we don't understand as well. 49 00:03:11,520 --> 00:03:14,040 Speaker 1: It's really strange. It doesn't play well with the other forces. 50 00:03:14,400 --> 00:03:17,400 Speaker 1: It's very, very weak. It's a total mystery to science, 51 00:03:17,480 --> 00:03:20,160 Speaker 1: except that we have a theory which works beautifully. Right. 52 00:03:20,200 --> 00:03:23,200 Speaker 1: We can calculate exactly how mercury orbits the Sun. We 53 00:03:23,200 --> 00:03:25,880 Speaker 1: can send things into outer space and note with two 54 00:03:25,919 --> 00:03:28,400 Speaker 1: millimeter precision exactly where they're going to land. We have 55 00:03:28,520 --> 00:03:31,360 Speaker 1: a working theory that we can use, right, but we 56 00:03:31,440 --> 00:03:34,400 Speaker 1: don't understand it on a conceptual level. We have these basic, 57 00:03:34,520 --> 00:03:37,240 Speaker 1: deep questions about about what gravity is and how the 58 00:03:37,320 --> 00:03:39,840 Speaker 1: universe works because of it. So it's a weird question, 59 00:03:40,160 --> 00:03:42,560 Speaker 1: and maybe one of the people hadn't thought about before. 60 00:03:43,000 --> 00:03:45,240 Speaker 1: So Daniel went out as usual and ask people on 61 00:03:45,280 --> 00:03:47,960 Speaker 1: the street, why do you think gravity is so weak. 62 00:03:48,240 --> 00:03:50,440 Speaker 1: Here's what a random selection of folks who are willing 63 00:03:50,440 --> 00:03:52,480 Speaker 1: to talk to me on a Tuesday morning had to 64 00:03:52,480 --> 00:03:55,600 Speaker 1: say about gravity. I don't know. I should don't know 65 00:03:55,680 --> 00:03:57,880 Speaker 1: about that, all right, I was. I was thought it 66 00:03:57,880 --> 00:04:03,720 Speaker 1: was a pretty strong force. So I don't know. But yeah, because, um, 67 00:04:03,760 --> 00:04:06,480 Speaker 1: it depends on the distance and it's long range one, 68 00:04:06,880 --> 00:04:08,880 Speaker 1: so that's why we feel it's very weak most of 69 00:04:08,920 --> 00:04:13,200 Speaker 1: the time. Cool. No, okay, I have no I'm sorry, 70 00:04:13,280 --> 00:04:18,000 Speaker 1: it's not very fruitful. I have no idea, but I'd 71 00:04:18,000 --> 00:04:21,240 Speaker 1: be interested in finding out why. All right, that wasn't 72 00:04:21,279 --> 00:04:24,240 Speaker 1: that was pretty good. Most people weren't surprised when you 73 00:04:24,279 --> 00:04:27,520 Speaker 1: said gravity is weak. I don't know. I feel like 74 00:04:27,520 --> 00:04:29,320 Speaker 1: of all the questions I've asked people, this is the 75 00:04:29,360 --> 00:04:32,720 Speaker 1: one that flams them the most. You know. People were like, what, 76 00:04:32,880 --> 00:04:36,040 Speaker 1: I have no idea, or um, they had crazy ideas 77 00:04:36,040 --> 00:04:39,000 Speaker 1: why gravity must must be weak. I feel like, usually 78 00:04:39,040 --> 00:04:41,200 Speaker 1: we get one person who knows what the answer is 79 00:04:41,279 --> 00:04:43,440 Speaker 1: or has a good clue about what what's going on. 80 00:04:43,640 --> 00:04:46,080 Speaker 1: This time, I feel like almost everybody was pretty clueless. 81 00:04:46,120 --> 00:04:48,120 Speaker 1: I mean, one person said I always thought gravity was 82 00:04:48,120 --> 00:04:51,680 Speaker 1: pretty strong, right, which kind of sums up the situation. Right. 83 00:04:51,720 --> 00:04:55,040 Speaker 1: Gravity is omnipresent in our lives. It dominates our experience, 84 00:04:55,320 --> 00:04:58,039 Speaker 1: and yet it's so weak compared to the other really 85 00:04:58,080 --> 00:05:00,800 Speaker 1: powerful forces we've discovered. Well of people, A couple of 86 00:05:00,880 --> 00:05:04,440 Speaker 1: answers were that had to do with distance, Like, gravity 87 00:05:04,800 --> 00:05:07,560 Speaker 1: gets really weak with distance, that's right. And the problem 88 00:05:07,600 --> 00:05:09,640 Speaker 1: there is that all the forces get weak with distance, 89 00:05:09,800 --> 00:05:15,120 Speaker 1: like electromagnetism also falls as a as a distance grows. Right, 90 00:05:15,160 --> 00:05:17,760 Speaker 1: So all of these forces followed this one over our 91 00:05:17,839 --> 00:05:20,600 Speaker 1: squared rule or are as your distance from the thing 92 00:05:20,680 --> 00:05:24,839 Speaker 1: that's that's giving you the force, right, maybe maybe right? Maybe? Yeah, 93 00:05:24,920 --> 00:05:27,919 Speaker 1: mostly we think and uh, and so that can't be 94 00:05:27,960 --> 00:05:29,880 Speaker 1: the answer, right, because all the other forces have that 95 00:05:29,920 --> 00:05:31,640 Speaker 1: same feature. So when you say it's the weak is 96 00:05:31,720 --> 00:05:34,960 Speaker 1: it's not that it changes over distances differently than the 97 00:05:35,000 --> 00:05:37,320 Speaker 1: other forces. That's right. So maybe we should talk about 98 00:05:37,680 --> 00:05:40,640 Speaker 1: what the forces are and compare them to each other. 99 00:05:40,680 --> 00:05:45,320 Speaker 1: So focus and get understanding of how crazy weak gravity is. Right. So, Daniel, 100 00:05:45,320 --> 00:05:48,960 Speaker 1: what are the forces of nature besides a bad movie 101 00:05:49,000 --> 00:05:53,320 Speaker 1: with Ben Affleck in center Bullock? Well, I think comedy. 102 00:05:53,520 --> 00:05:57,279 Speaker 1: Comedy is definitely force of nature. You know, it solves 103 00:05:57,279 --> 00:06:00,240 Speaker 1: big problems around the world. You know. The fundamental forces 104 00:06:00,360 --> 00:06:04,400 Speaker 1: are electromagnetism, right, that's the one that controls electricity and 105 00:06:04,520 --> 00:06:07,240 Speaker 1: magnetism obviously and is responsible for the cool things like 106 00:06:07,640 --> 00:06:11,839 Speaker 1: light and lightning and all that all that cool stuff. Um. 107 00:06:11,880 --> 00:06:14,960 Speaker 1: And then there's the weak nuclear force, which is a 108 00:06:15,040 --> 00:06:18,440 Speaker 1: force which is responsible for radioactive decay of a nuclei. Right. 109 00:06:18,520 --> 00:06:21,279 Speaker 1: And the cool thing about electricity and magnetism and the 110 00:06:21,320 --> 00:06:24,000 Speaker 1: weak nuclear force is that we actually have shown that 111 00:06:24,040 --> 00:06:27,760 Speaker 1: there are two sides of the same coin as a particle. Physicists, 112 00:06:27,760 --> 00:06:29,599 Speaker 1: we refer to them as one force. We call it 113 00:06:29,640 --> 00:06:33,440 Speaker 1: the electro week. So sort of magnetism lost out there 114 00:06:33,440 --> 00:06:36,800 Speaker 1: in the name merger, right, it should be electro magnetic week. 115 00:06:36,839 --> 00:06:39,680 Speaker 1: But nobody voted to keep magnetism in the the name 116 00:06:39,720 --> 00:06:42,520 Speaker 1: of the partners on the law firm. Nobody, nobody lobbied 117 00:06:42,560 --> 00:06:49,599 Speaker 1: for weak electro or magneto weak force. Yeah. Yeah, again, 118 00:06:49,880 --> 00:06:52,720 Speaker 1: we are suffering the fate of some anonymous committee of 119 00:06:52,760 --> 00:06:54,839 Speaker 1: scientists that get to name these things. Right, who are 120 00:06:54,920 --> 00:06:57,360 Speaker 1: these people? It's probably some grad student, right or some 121 00:06:58,120 --> 00:07:02,240 Speaker 1: you know, like this is really weird call it this. Yeah. 122 00:07:02,320 --> 00:07:05,280 Speaker 1: So we have electricity and magnetism, which is a single force. 123 00:07:05,320 --> 00:07:07,520 Speaker 1: We have the weak nuclear force, which is really should 124 00:07:07,520 --> 00:07:10,560 Speaker 1: be combined with electricity magnetism. And then there's the strong 125 00:07:10,720 --> 00:07:12,520 Speaker 1: nuclear force, and this is the one that holds the 126 00:07:12,600 --> 00:07:15,160 Speaker 1: nucleus together. You know, the nucleus is just a bunch 127 00:07:15,200 --> 00:07:19,320 Speaker 1: of positively charged protons and neutral neutrons, right, so it's 128 00:07:19,400 --> 00:07:22,520 Speaker 1: only positively charged particles in the nucleus. So you might think, 129 00:07:22,560 --> 00:07:24,920 Speaker 1: what it even holds the nucleus together, right, you have 130 00:07:24,960 --> 00:07:28,200 Speaker 1: all this positively charged stuff should be repelling themselves. Well, 131 00:07:28,240 --> 00:07:30,920 Speaker 1: it's the strong nuclear force, and it does so by 132 00:07:30,920 --> 00:07:34,720 Speaker 1: exchanging these crazy little particles we call gluons, and that 133 00:07:34,800 --> 00:07:37,360 Speaker 1: holds the nucleus together, and it's pretty strong. It's even 134 00:07:37,440 --> 00:07:40,680 Speaker 1: stronger than electromagnetism. Well, let's take a step back. So 135 00:07:40,760 --> 00:07:45,400 Speaker 1: in the universe there's stuff. There's like, yes, affirm that 136 00:07:45,440 --> 00:07:49,400 Speaker 1: there is stuff in without reservation, there is stuff. I'm 137 00:07:49,400 --> 00:07:52,480 Speaker 1: glad we saw that question. But I mean it's like 138 00:07:52,520 --> 00:07:56,000 Speaker 1: there's stuff that has substance to it, that has masked 139 00:07:56,000 --> 00:07:58,240 Speaker 1: to it, or you know that it sort of exists. 140 00:07:58,240 --> 00:08:01,240 Speaker 1: And then there's also besides the at how these things 141 00:08:01,600 --> 00:08:03,920 Speaker 1: interact with each other, like how they affect each other 142 00:08:04,080 --> 00:08:07,040 Speaker 1: that's right. There's the matter and then there's the forces. Right. 143 00:08:07,120 --> 00:08:09,120 Speaker 1: The forces affect how they interact with each other, and 144 00:08:09,160 --> 00:08:11,640 Speaker 1: that's pretty much the universe. That's that's like, it's matter 145 00:08:11,720 --> 00:08:14,679 Speaker 1: and forces. Yeah. One way to look at the universe 146 00:08:14,760 --> 00:08:17,320 Speaker 1: is that it's particles, right, or you would say matter 147 00:08:17,360 --> 00:08:20,440 Speaker 1: and their forces. In modern particle physics we think about 148 00:08:20,560 --> 00:08:23,120 Speaker 1: one level deeper, which if we think of quantum fields, 149 00:08:23,520 --> 00:08:26,840 Speaker 1: and quantum fields are responsible both for matter and for forces. 150 00:08:27,320 --> 00:08:29,560 Speaker 1: So we can talk about that maybe in another podcast. 151 00:08:29,600 --> 00:08:32,040 Speaker 1: What is a quantum field and how can I get one? 152 00:08:32,120 --> 00:08:34,600 Speaker 1: You know for leaser rent um? What can they do 153 00:08:34,679 --> 00:08:36,600 Speaker 1: for me? But yeah, I think it's it's fair still 154 00:08:36,720 --> 00:08:40,480 Speaker 1: to think about the universe in terms of particles and forces. 155 00:08:40,640 --> 00:08:56,080 Speaker 1: On that note, let's take a quick break. There are 156 00:08:56,120 --> 00:08:58,880 Speaker 1: only four kinds of forces. Yeah, there are four kinds 157 00:08:58,880 --> 00:09:03,360 Speaker 1: of forces. So after magnetism, weak nuclear force, strong nuclear force, 158 00:09:03,440 --> 00:09:06,120 Speaker 1: and then of course gravity, right, that's the fourth force 159 00:09:06,120 --> 00:09:10,360 Speaker 1: that we've discovered. The fascinating thing is that different particles 160 00:09:10,440 --> 00:09:13,840 Speaker 1: feel different forces, right, Like, some particles feel this set 161 00:09:13,840 --> 00:09:17,160 Speaker 1: of forces, some particles feel those set of forces. For example, right, 162 00:09:17,559 --> 00:09:22,800 Speaker 1: particles with electric charge feel electromagnetism. Right. The electron, for example, 163 00:09:22,880 --> 00:09:26,600 Speaker 1: is negatively charged, the proton is positively charged. You bring 164 00:09:26,640 --> 00:09:28,920 Speaker 1: them close together, they're gonna pull on each other. They're 165 00:09:28,920 --> 00:09:32,040 Speaker 1: gonna suck each other together, right, because they have opposite charges. 166 00:09:32,080 --> 00:09:34,920 Speaker 1: We all know that, um. But you bring a neutral 167 00:09:34,960 --> 00:09:37,680 Speaker 1: particle nearby, it just totally ignores it. Right, It doesn't 168 00:09:37,760 --> 00:09:41,120 Speaker 1: feel it at all. Right, It's like it's like somebody's 169 00:09:41,160 --> 00:09:43,360 Speaker 1: walking through a crowd of people shouting, but they have 170 00:09:43,400 --> 00:09:45,880 Speaker 1: headphones on so they can't hear anything, and they're totally 171 00:09:45,960 --> 00:09:47,920 Speaker 1: oblivious to it. It's kind of like how we talked 172 00:09:47,920 --> 00:09:51,320 Speaker 1: about in a previous podcast. They're almost like languages or 173 00:09:51,400 --> 00:09:54,320 Speaker 1: like social media platforms. Like some people are on Twitter, 174 00:09:54,559 --> 00:09:56,720 Speaker 1: some people are on Facebook, but some people are not 175 00:09:56,800 --> 00:09:58,640 Speaker 1: on this. And so if somebody if you're not on 176 00:09:58,640 --> 00:10:00,320 Speaker 1: Twitter and so many sense to your tweet, you're not 177 00:10:00,320 --> 00:10:02,560 Speaker 1: going to get it. And so it's just different ways 178 00:10:02,640 --> 00:10:05,240 Speaker 1: the particles in right, that's right. Gravity is the Google 179 00:10:05,280 --> 00:10:12,240 Speaker 1: plus social media right because nobody uses the trendstor it's 180 00:10:12,320 --> 00:10:16,640 Speaker 1: ancient but powerless. Yeah, And so different particles feel different forces. 181 00:10:16,640 --> 00:10:20,120 Speaker 1: And for example, an electron, while it feels electromagnetism. Because 182 00:10:20,120 --> 00:10:22,880 Speaker 1: it has a negative charge, it doesn't feel a strong 183 00:10:22,920 --> 00:10:25,720 Speaker 1: force at all. It will pass right by a bunch 184 00:10:25,720 --> 00:10:27,840 Speaker 1: of particles that are really tugging on each other with 185 00:10:27,880 --> 00:10:31,160 Speaker 1: a strong force and not be affected at all. Whereas corks. 186 00:10:31,559 --> 00:10:34,760 Speaker 1: Corks feel all the forces. They feel a strong force, 187 00:10:35,160 --> 00:10:37,440 Speaker 1: which is how they get pulled together in the nucleus. Remember, 188 00:10:37,440 --> 00:10:41,040 Speaker 1: protons and neutrons are made of quarks. Quarks feel electromagnetism 189 00:10:41,040 --> 00:10:43,760 Speaker 1: because they have electric charge. They feel the weak force. 190 00:10:43,960 --> 00:10:46,160 Speaker 1: They also feel gravity, of course, because they have mass. 191 00:10:46,160 --> 00:10:50,040 Speaker 1: So quarks get their fingers in everything they feel. They 192 00:10:50,080 --> 00:10:53,160 Speaker 1: get the feels for everything. They feel everything's right, They 193 00:10:53,200 --> 00:10:57,640 Speaker 1: got the strong feels. Course, they're really deeply emotional part 194 00:10:57,640 --> 00:11:00,960 Speaker 1: of um. And on the other side of the spectrum, 195 00:11:00,960 --> 00:11:04,080 Speaker 1: you've got things like neutrinos. Patrinos don't have electric charge, 196 00:11:04,360 --> 00:11:07,880 Speaker 1: so they ignore all electricity magnetism, right, They don't interact 197 00:11:07,920 --> 00:11:11,319 Speaker 1: with light. They're invisible. They pass right through anything that that. 198 00:11:12,360 --> 00:11:16,000 Speaker 1: They ignore electro magnetic bonds, so they pass through most materials. 199 00:11:16,360 --> 00:11:18,760 Speaker 1: They don't feel the strong force. The only way they 200 00:11:18,760 --> 00:11:20,880 Speaker 1: interact is with the weak force, and the weak force 201 00:11:20,960 --> 00:11:23,480 Speaker 1: is pretty weak, which is why neutrinos can mostly just 202 00:11:23,520 --> 00:11:31,160 Speaker 1: pass through matter unaffected. So we have four fundamental forces, right, 203 00:11:31,200 --> 00:11:33,439 Speaker 1: and gravity is one of these forces. And so when 204 00:11:33,440 --> 00:11:36,480 Speaker 1: you say that antravity is weak, you actually mean it's 205 00:11:36,559 --> 00:11:39,960 Speaker 1: weak compared to these other three forces, that's right. And 206 00:11:40,000 --> 00:11:43,160 Speaker 1: so the ranking is the strong force is the strongest, 207 00:11:43,720 --> 00:11:46,800 Speaker 1: so that one is actually well named. Congratulations, you know, 208 00:11:46,840 --> 00:11:50,040 Speaker 1: anonymous group of scientists. Yeah, yeah, we should be called 209 00:11:50,040 --> 00:11:55,120 Speaker 1: the as currently known to be the strongest force force. Um. 210 00:11:55,360 --> 00:11:58,600 Speaker 1: Right after that comes electromagnetism, and you know, we know 211 00:11:58,679 --> 00:12:00,559 Speaker 1: that force is pretty powerful. You stick your finger in 212 00:12:00,559 --> 00:12:03,480 Speaker 1: a socket, you're going to feel the wrath of electromagnetism, right. 213 00:12:03,520 --> 00:12:05,920 Speaker 1: It's it's not an unfamiliar feeling, right, right to think 214 00:12:05,960 --> 00:12:08,480 Speaker 1: your finger in anything? You feel it, right, because it's 215 00:12:08,640 --> 00:12:13,000 Speaker 1: electromagnetism is the force that keeps you from basically passing 216 00:12:13,040 --> 00:12:17,640 Speaker 1: through the table or passing through your car. Right, that's right. 217 00:12:17,679 --> 00:12:20,960 Speaker 1: Because electromagnetism is the basis of chemical bonds, right. And 218 00:12:21,080 --> 00:12:23,400 Speaker 1: chemical bonds are really the thing that form the structure 219 00:12:23,440 --> 00:12:25,520 Speaker 1: of your body. Right. You think if your body is 220 00:12:25,520 --> 00:12:27,839 Speaker 1: like a bunch of particles, but it's held together by 221 00:12:27,840 --> 00:12:30,920 Speaker 1: all these forces, it's like a chain link fence binding 222 00:12:30,960 --> 00:12:33,640 Speaker 1: together these little particles and prevents you from passing through 223 00:12:33,679 --> 00:12:36,880 Speaker 1: something else. Yeah, so we got the strong force, and 224 00:12:36,920 --> 00:12:40,560 Speaker 1: then electromagnetism, and then actually the weak nuclear force. Right, 225 00:12:40,600 --> 00:12:43,480 Speaker 1: this is the force that like powers neutrinos and radioactive decay. 226 00:12:43,760 --> 00:12:47,920 Speaker 1: It's much weaker than electromagnetism um and much weaker than 227 00:12:47,960 --> 00:12:51,360 Speaker 1: the strong force. Even weaker than the weak is gravity. 228 00:12:51,400 --> 00:12:54,920 Speaker 1: That's right. If you make a list like strong force, electromagnetism, 229 00:12:55,000 --> 00:12:57,480 Speaker 1: the weak force, then you should leave like a hundred 230 00:12:57,480 --> 00:13:00,920 Speaker 1: blank pages and then you get to grab because when 231 00:13:00,920 --> 00:13:03,480 Speaker 1: we compare these forces, we put things like an equal 232 00:13:03,520 --> 00:13:07,040 Speaker 1: distance apart and compare the strength of the forces. Gravity 233 00:13:07,080 --> 00:13:11,080 Speaker 1: is ten to the thirty six times weaker than the 234 00:13:11,080 --> 00:13:14,920 Speaker 1: weak force. But that's ten with thirty six zeros in 235 00:13:14,960 --> 00:13:16,920 Speaker 1: front of it. But it isn't that sort of a 236 00:13:16,920 --> 00:13:20,280 Speaker 1: matter of units or scale, do you know what I mean? Like, 237 00:13:20,640 --> 00:13:24,839 Speaker 1: it's much weaker, but only if you compare apples to apples, right, 238 00:13:25,160 --> 00:13:27,480 Speaker 1: or orange to oranges. That's right. But put two protons 239 00:13:27,559 --> 00:13:30,559 Speaker 1: next to each other, right, Two protons have a certain 240 00:13:30,600 --> 00:13:32,760 Speaker 1: amount of mass and a certain amount of electric charge, 241 00:13:33,200 --> 00:13:35,360 Speaker 1: and the force of their charges is going to be 242 00:13:35,480 --> 00:13:38,560 Speaker 1: much much stronger than the force from their masses. So yeah, 243 00:13:38,600 --> 00:13:41,440 Speaker 1: if everything was much much more massive, then there would 244 00:13:41,480 --> 00:13:44,120 Speaker 1: be stronger gravity. But you can compare these things apples 245 00:13:44,120 --> 00:13:46,400 Speaker 1: to apples by comparing them, you know, the same distance 246 00:13:46,440 --> 00:13:49,120 Speaker 1: and the same basic unit of interaction. Right, But what 247 00:13:49,160 --> 00:13:52,400 Speaker 1: if you take an apple put it next to another apple? Well, 248 00:13:52,440 --> 00:13:54,319 Speaker 1: I think you can do that experiment. Nothing's going to 249 00:13:54,400 --> 00:13:56,839 Speaker 1: happen because gravity is so weak. Right. You don't see 250 00:13:56,840 --> 00:13:59,280 Speaker 1: two apples like pulling themselves together on the counter, right, 251 00:13:59,320 --> 00:14:02,680 Speaker 1: then they'll alden apple collider um. You know, the apples 252 00:14:02,679 --> 00:14:05,200 Speaker 1: are not drawn to each other. Gravity is a super 253 00:14:05,240 --> 00:14:07,319 Speaker 1: weak force, and you can see this yourself. Right, you 254 00:14:07,840 --> 00:14:11,520 Speaker 1: can do an experiment where you counter the entire gravitational 255 00:14:11,559 --> 00:14:14,640 Speaker 1: force of an enormous celestial body like the Earth. Right, 256 00:14:15,200 --> 00:14:18,199 Speaker 1: take a small kitchen magnet and use it to hold 257 00:14:18,280 --> 00:14:20,520 Speaker 1: up a nail and think about what's happening there. Right, 258 00:14:20,560 --> 00:14:23,960 Speaker 1: you have the nail is being pulled down by every 259 00:14:24,080 --> 00:14:26,560 Speaker 1: single rock in the Earth. It's pulling with all of 260 00:14:26,600 --> 00:14:30,480 Speaker 1: its gravity. But a tiny little kitchen magnet totally overcomes that. 261 00:14:31,760 --> 00:14:34,320 Speaker 1: It can lift the nail even though it's pulling. It's 262 00:14:34,360 --> 00:14:37,760 Speaker 1: being pulled down by the whole entire planet Earth, right exactly. Now, 263 00:14:37,800 --> 00:14:41,120 Speaker 1: imagine a magnet the size of the Earth, right, I 264 00:14:41,120 --> 00:14:44,440 Speaker 1: mean that would be that would be extraordinarily powerful. And 265 00:14:44,480 --> 00:14:47,400 Speaker 1: so you have basically like a gravitational blob the size 266 00:14:47,440 --> 00:14:53,320 Speaker 1: of the Earth. Still pretty ineffective compared to electromagnetism. So 267 00:14:53,320 --> 00:14:57,520 Speaker 1: so it's weak if you sort of compare it by object, 268 00:14:58,080 --> 00:14:59,600 Speaker 1: Like you said, if you take a proton and put 269 00:14:59,600 --> 00:15:02,480 Speaker 1: it next to proton, the the force are going to 270 00:15:02,560 --> 00:15:05,680 Speaker 1: feel from electro magnetism is so much bigger than the 271 00:15:05,840 --> 00:15:07,960 Speaker 1: force of gravity. They're going to feel towards each other 272 00:15:08,400 --> 00:15:12,360 Speaker 1: the same with like two electrons or two cords and things. 273 00:15:12,560 --> 00:15:14,640 Speaker 1: So in the scale of like the particles that we know, 274 00:15:15,080 --> 00:15:18,920 Speaker 1: it's a really weak force, that's right, exactly. And yet 275 00:15:19,280 --> 00:15:21,480 Speaker 1: and yet it seems to dominate. Right. That's a bit 276 00:15:21,520 --> 00:15:24,440 Speaker 1: of a puzzle. Like, on one hand, it's super duper weak, 277 00:15:24,520 --> 00:15:26,360 Speaker 1: and we're telling you that it hardly counts for anything. 278 00:15:26,400 --> 00:15:28,880 Speaker 1: On the other hand, it's responsible for the structure of 279 00:15:28,880 --> 00:15:31,160 Speaker 1: the Solar System, man for the galaxy, and it's the 280 00:15:31,160 --> 00:15:33,720 Speaker 1: reason the universe looks the way it is, right, And 281 00:15:33,760 --> 00:15:35,520 Speaker 1: so that can be confusing to people, Like how do 282 00:15:35,560 --> 00:15:38,040 Speaker 1: you reconcile those two things in your head? Yeah, Like 283 00:15:38,080 --> 00:15:41,040 Speaker 1: why doesn't the Earth feel an electromagnetic force with the Sun, 284 00:15:41,360 --> 00:15:44,320 Speaker 1: which it would be so much bigger than the force 285 00:15:44,360 --> 00:15:47,200 Speaker 1: of gravity. Yeah, what, it would be pretty shocking. And 286 00:15:47,320 --> 00:15:50,440 Speaker 1: and that's actually the reason is um gravity is different 287 00:15:50,480 --> 00:15:53,280 Speaker 1: from the other forces and that it can't be canceled out. Right, 288 00:15:53,560 --> 00:15:56,680 Speaker 1: if there was some huge electrostatic difference between the Sun 289 00:15:56,720 --> 00:15:58,680 Speaker 1: and the Earth, like a bunch of positive charges there 290 00:15:58,720 --> 00:16:01,280 Speaker 1: and a bunch of negative charges year, it would create 291 00:16:01,400 --> 00:16:05,560 Speaker 1: such an enormous force that it would be very quickly balanced. 292 00:16:05,800 --> 00:16:08,360 Speaker 1: Like that's what lightning is, right, When there's a charge 293 00:16:08,400 --> 00:16:12,520 Speaker 1: differential between clouds and the ground, it's it doesn't take 294 00:16:12,560 --> 00:16:15,360 Speaker 1: that much before those charges want to rearrange themselves to 295 00:16:15,400 --> 00:16:18,160 Speaker 1: a lower energy configuration. They rushed down to the ground, 296 00:16:18,240 --> 00:16:19,800 Speaker 1: or they rushed up to the clouds and they jump 297 00:16:20,880 --> 00:16:23,960 Speaker 1: to balance themselves up. Because you have two kinds of charges, 298 00:16:23,960 --> 00:16:26,600 Speaker 1: you have positive and you have negative, so you can 299 00:16:26,760 --> 00:16:30,440 Speaker 1: find an arrangement where basically everybody is happy. It's an equilibrium, right, 300 00:16:30,640 --> 00:16:33,120 Speaker 1: But that's not true for gravity, Okay, I get it. 301 00:16:33,160 --> 00:16:36,080 Speaker 1: So for example, if the Earth was every particle on 302 00:16:36,120 --> 00:16:40,080 Speaker 1: Earth had a positive electromagnetic charge and every particle in 303 00:16:40,120 --> 00:16:43,440 Speaker 1: the Sun had a negative electromagnetic charge, there would be 304 00:16:43,480 --> 00:16:49,440 Speaker 1: a humongous pool from electromagnetism pulling the Earth into the Sun. Yeah, 305 00:16:49,480 --> 00:16:54,480 Speaker 1: we'd be toasted pretty quick. Yeah, I would be huge. 306 00:16:54,840 --> 00:16:57,040 Speaker 1: Even the opposite if we were all positive and the 307 00:16:57,080 --> 00:16:59,400 Speaker 1: Sun was all positive, we would get shot out of 308 00:16:59,400 --> 00:17:02,600 Speaker 1: the solar stem very quickly, that's right. And that's why 309 00:17:02,680 --> 00:17:05,280 Speaker 1: you know, early days of the Solar system being formed, 310 00:17:05,280 --> 00:17:08,840 Speaker 1: you have these gases and the gas and dust coalescing, 311 00:17:09,080 --> 00:17:13,119 Speaker 1: and very rapidly things neutralize, right, because anything that feels 312 00:17:13,160 --> 00:17:16,439 Speaker 1: an electrostatic force to something else is going to find 313 00:17:16,480 --> 00:17:18,760 Speaker 1: the opposite charge and they're going to coalesce and they're 314 00:17:18,760 --> 00:17:21,119 Speaker 1: gonna make something neutral. Right. That's why most of the 315 00:17:21,200 --> 00:17:23,680 Speaker 1: things around you are neutral, Right, Most of the elements 316 00:17:23,880 --> 00:17:27,679 Speaker 1: are neutral, because any deviation from neutral results in a 317 00:17:27,680 --> 00:17:31,440 Speaker 1: powerful force to neutralize it. So, thankfully the Earth is 318 00:17:31,480 --> 00:17:34,359 Speaker 1: made out of both like equal amounts of positive and 319 00:17:34,359 --> 00:17:39,439 Speaker 1: negative particles, right, that's right. Thankfully we're sort of balanced electromagnetically, 320 00:17:39,720 --> 00:17:42,439 Speaker 1: and so even if the Sun was all positive, we 321 00:17:42,480 --> 00:17:45,359 Speaker 1: would look like neutral, like a neutral ball to to 322 00:17:45,440 --> 00:17:48,119 Speaker 1: the sun. Yeah, that's right, we're on large scales. The 323 00:17:48,160 --> 00:17:49,960 Speaker 1: Earth is neutral, right, I mean there might be some 324 00:17:50,520 --> 00:17:53,879 Speaker 1: residual positive or negative charge depending on the solar wind, etcetera. 325 00:17:54,119 --> 00:17:57,600 Speaker 1: But basically the Earth is neutral, and so the largest 326 00:17:57,640 --> 00:18:00,440 Speaker 1: force of the Earth feels is the gravity in the sun, 327 00:18:00,520 --> 00:18:03,440 Speaker 1: even though gravity is super duper weak. Right, it doesn't 328 00:18:03,440 --> 00:18:05,440 Speaker 1: take a lot to counteract gravity. But it's the only 329 00:18:05,480 --> 00:18:08,080 Speaker 1: player left because everybody else is sort of pair it 330 00:18:08,200 --> 00:18:10,760 Speaker 1: up and danced off for the night, and gravity is 331 00:18:10,800 --> 00:18:14,560 Speaker 1: just there left holding the bag. And gravity can't be balanced, right. 332 00:18:14,760 --> 00:18:17,320 Speaker 1: You feel gravity if you have any mass, right, But 333 00:18:17,359 --> 00:18:19,879 Speaker 1: there's only positive masses and no such thing as a 334 00:18:20,040 --> 00:18:24,480 Speaker 1: negative mass to give anti gravity. Well, let's keep going, 335 00:18:24,600 --> 00:18:40,760 Speaker 1: but first let's take a quick break. Okay, So that's 336 00:18:40,760 --> 00:18:45,280 Speaker 1: how gravity is so much weaker than the other forces. Um, 337 00:18:45,320 --> 00:18:48,080 Speaker 1: so how's it different than the other three forces of nature? 338 00:18:48,280 --> 00:18:51,560 Speaker 1: There's like no end to to weys, the gravity is weird, 339 00:18:51,640 --> 00:18:53,560 Speaker 1: you know, there's no end to like the puzzles of 340 00:18:53,600 --> 00:18:57,720 Speaker 1: Gravity's fascinating bottomless pit. That's right, it's a black hole 341 00:18:58,080 --> 00:19:01,520 Speaker 1: of questions. Um. And one of my favorites is just 342 00:19:01,600 --> 00:19:05,000 Speaker 1: that we have no way to sort of fit gravity 343 00:19:05,040 --> 00:19:07,960 Speaker 1: in with the way the universe works according to everything else. 344 00:19:08,320 --> 00:19:10,679 Speaker 1: You know, we talked earlier about how we have particles 345 00:19:10,720 --> 00:19:14,560 Speaker 1: and we have forces or quantum fields equivalently, and that's 346 00:19:14,600 --> 00:19:17,040 Speaker 1: a really successful way to describe the universe. You know, 347 00:19:17,119 --> 00:19:19,520 Speaker 1: we have the Large Hadron Collider to explore these things, 348 00:19:19,560 --> 00:19:22,520 Speaker 1: really high energies, and we've understood all sorts of things 349 00:19:22,600 --> 00:19:26,560 Speaker 1: using this theory. But that theory is used as quantum mechanics. 350 00:19:26,920 --> 00:19:29,800 Speaker 1: So the way we describe interactions, you know, the way 351 00:19:29,840 --> 00:19:33,159 Speaker 1: we talk about two electrons um repelling each other, or 352 00:19:33,160 --> 00:19:36,520 Speaker 1: the way lightning is formed or anything involves passing quantum 353 00:19:36,560 --> 00:19:39,640 Speaker 1: particles back and forth. And that's just not true for gravity. 354 00:19:40,119 --> 00:19:42,879 Speaker 1: What does that mean? Passing particles back and forth? Like 355 00:19:42,920 --> 00:19:46,840 Speaker 1: when like if I have two magnets and they're attracted 356 00:19:46,880 --> 00:19:49,040 Speaker 1: to each other, they're not. They're not It's not like 357 00:19:49,040 --> 00:19:52,600 Speaker 1: an invisible telekinesis pulling on each other. They're actually swapping 358 00:19:52,640 --> 00:19:54,720 Speaker 1: particles and I can't see that. Is that kind of 359 00:19:54,720 --> 00:19:57,280 Speaker 1: what you mean? That's exactly what I mean. Um that 360 00:19:57,520 --> 00:20:00,440 Speaker 1: the way two things interact via some four is by 361 00:20:00,480 --> 00:20:04,679 Speaker 1: exchanging particles. And so for example, electromagnetism, right, is the 362 00:20:04,720 --> 00:20:08,480 Speaker 1: force behind a magnet, And the way electromagnetism works, we 363 00:20:08,520 --> 00:20:11,359 Speaker 1: think at a sort of microscopic particle level, is that 364 00:20:11,400 --> 00:20:14,640 Speaker 1: there's a particle that transmits that force, that sends sort 365 00:20:14,640 --> 00:20:17,199 Speaker 1: of the information back and forth between two things that 366 00:20:17,240 --> 00:20:20,399 Speaker 1: are feeling it. And in the case of electromagnetism, that 367 00:20:20,480 --> 00:20:23,720 Speaker 1: particle is the photon. Right. The particle is also a 368 00:20:23,760 --> 00:20:26,760 Speaker 1: packet of light. So each of the quantum forces that 369 00:20:26,760 --> 00:20:30,240 Speaker 1: we talked about before, electromagnetism, the weak force and the 370 00:20:30,280 --> 00:20:33,240 Speaker 1: strong force, each of them have a particle we associate 371 00:20:33,320 --> 00:20:36,160 Speaker 1: with it. And that's not just like some name tag 372 00:20:36,200 --> 00:20:37,880 Speaker 1: we put on and say, hey, you get this one, 373 00:20:37,920 --> 00:20:40,120 Speaker 1: you get this one. We think that that's the particle 374 00:20:40,160 --> 00:20:43,560 Speaker 1: that's responsible for making the force work. So when two 375 00:20:43,560 --> 00:20:46,720 Speaker 1: electrons come near each other, how do they repel each other? 376 00:20:46,720 --> 00:20:49,560 Speaker 1: How does that actually happen? But we think that they 377 00:20:49,600 --> 00:20:54,320 Speaker 1: send photons out right, The electric field of a moving electron, right, 378 00:20:54,359 --> 00:20:59,320 Speaker 1: and accelerating electron generates photons, and those photons um interact 379 00:20:59,320 --> 00:21:02,640 Speaker 1: with the other chron's and so basically the passing messages 380 00:21:02,680 --> 00:21:06,359 Speaker 1: back and forth using these quantum particles. So gravity is 381 00:21:06,400 --> 00:21:10,040 Speaker 1: weird because we don't know that there is an quantum 382 00:21:10,080 --> 00:21:14,440 Speaker 1: particle being exchanged when two things get attracted gravitationally. That's right. 383 00:21:14,440 --> 00:21:16,960 Speaker 1: So we have this great framework. We say, oh, maybe 384 00:21:17,000 --> 00:21:21,840 Speaker 1: all forces are quantum mechanical fields interacting with each other. Right, 385 00:21:22,000 --> 00:21:24,560 Speaker 1: Let's apply that to the electromagnetic field. Yeah it works. 386 00:21:24,680 --> 00:21:26,639 Speaker 1: Let's apply that to the weak force. Yeah it works. 387 00:21:26,800 --> 00:21:29,080 Speaker 1: Let's applies to the strong force. Oh cool, it works. 388 00:21:29,280 --> 00:21:31,560 Speaker 1: Maybe this is something deep about the way the universe works. 389 00:21:31,720 --> 00:21:37,000 Speaker 1: Let's apply to gravity. Oh it doesn't work, right, So 390 00:21:37,040 --> 00:21:38,399 Speaker 1: what does that mean? What does it mean when I 391 00:21:38,400 --> 00:21:40,879 Speaker 1: say it doesn't work? Well? For a theory to work, 392 00:21:41,240 --> 00:21:44,600 Speaker 1: it has to provide predictions for experiments. You have to 393 00:21:44,640 --> 00:21:47,320 Speaker 1: be able to say, okay, theory, what would happen in 394 00:21:47,359 --> 00:21:50,920 Speaker 1: this configuration if I shot a proton and another particle. 395 00:21:51,359 --> 00:21:53,280 Speaker 1: Predict what would happen, and then you can go off 396 00:21:53,280 --> 00:21:56,200 Speaker 1: and do the experiments and compare it. Right. Well, when 397 00:21:56,200 --> 00:21:57,760 Speaker 1: you do that for gravity, you try to form a 398 00:21:57,880 --> 00:22:02,120 Speaker 1: quantum theory of gravity, it doesn't work. You get nonsense answers. 399 00:22:02,400 --> 00:22:05,760 Speaker 1: You can answers like infinity right, or things disappear, or 400 00:22:06,000 --> 00:22:09,480 Speaker 1: it just it doesn't mathematically function like there's no way 401 00:22:09,520 --> 00:22:12,600 Speaker 1: to build a theory of gravity that we've discovered so 402 00:22:12,640 --> 00:22:16,399 Speaker 1: far that works, that actually explains the way these things happen. 403 00:22:17,200 --> 00:22:19,760 Speaker 1: There are a few candidates out there there pretty far 404 00:22:19,880 --> 00:22:23,159 Speaker 1: from being a functional theory of quantum gravity. There's a 405 00:22:23,240 --> 00:22:26,320 Speaker 1: loop quantum gravity or string theory. But the basic problem 406 00:22:26,480 --> 00:22:30,159 Speaker 1: is that quantum mechanics and general relativity, which is our 407 00:22:30,200 --> 00:22:32,800 Speaker 1: best theory of gravity, do not play well together. And 408 00:22:32,840 --> 00:22:37,400 Speaker 1: we have no functioning quantum theory of gravity. So does 409 00:22:37,440 --> 00:22:39,439 Speaker 1: that mean that we don't have the right theory or 410 00:22:39,520 --> 00:22:43,160 Speaker 1: is that gravity is just not quantum in nature? That's 411 00:22:43,200 --> 00:22:45,639 Speaker 1: exactly the question we don't know the answer to. Right 412 00:22:45,920 --> 00:22:47,840 Speaker 1: In a hundred years from now, somebody will know the 413 00:22:47,880 --> 00:22:50,200 Speaker 1: answer that I hope, and they'll look back and they'll wonder, 414 00:22:50,320 --> 00:22:52,480 Speaker 1: you know, why do those guys see the clues but 415 00:22:52,560 --> 00:22:54,760 Speaker 1: we don't know. It could be that there is a 416 00:22:54,840 --> 00:22:57,120 Speaker 1: quantum theory gravity, we're just not smart enough to think 417 00:22:57,160 --> 00:22:59,360 Speaker 1: it up yet, right, Like the right person hasn't been 418 00:22:59,400 --> 00:23:01,919 Speaker 1: born yet to put the math together, or maybe it 419 00:23:01,960 --> 00:23:04,080 Speaker 1: requires a different kind of math that we're using. Right, 420 00:23:04,119 --> 00:23:06,600 Speaker 1: there's some assumption we're making that's a that's a mistake 421 00:23:06,840 --> 00:23:08,920 Speaker 1: or maybe just giving it a wrong name, like maybe 422 00:23:08,920 --> 00:23:19,639 Speaker 1: it should be or gravitinos grabby toss exactly. That's definitely 423 00:23:19,680 --> 00:23:21,760 Speaker 1: the problem. That's step number one when we made a mistake, 424 00:23:21,760 --> 00:23:24,520 Speaker 1: and step number one when we could define the particle um. 425 00:23:24,720 --> 00:23:27,240 Speaker 1: The other option, of course, is that maybe gravity is 426 00:23:27,280 --> 00:23:30,040 Speaker 1: not a quantum force the way the other forces are. Right, 427 00:23:30,320 --> 00:23:32,960 Speaker 1: the other forces we call them quantum forces because they're 428 00:23:33,000 --> 00:23:36,520 Speaker 1: well described by quantum mechanics, but gravity is kind of different. 429 00:23:36,560 --> 00:23:40,320 Speaker 1: I mean, the current theory we have a gravity general relativity. 430 00:23:40,600 --> 00:23:43,040 Speaker 1: It doesn't like to describe gravity as a force, right, 431 00:23:43,119 --> 00:23:46,520 Speaker 1: describes gravity instead as a bending of space. It says 432 00:23:46,880 --> 00:23:49,879 Speaker 1: that when you have mass somewhere in space, space no 433 00:23:49,920 --> 00:23:54,240 Speaker 1: longer becomes straight, becomes bent, so the things moving curves 434 00:23:54,240 --> 00:23:57,600 Speaker 1: and circles. And it's not like an actual just a 435 00:23:57,600 --> 00:24:01,720 Speaker 1: mathematical nuance where a mathematical perspe active. What's really confirms 436 00:24:01,840 --> 00:24:05,080 Speaker 1: it is the idea that gravity can affect things that 437 00:24:05,200 --> 00:24:07,480 Speaker 1: don't have mass. Right, That's how we know it's more 438 00:24:07,520 --> 00:24:10,199 Speaker 1: than just a force between things that have mass. It 439 00:24:10,240 --> 00:24:14,240 Speaker 1: actually like affects space for things that don't have mass. Right, 440 00:24:14,440 --> 00:24:17,560 Speaker 1: that's exactly right. So if you shoot a photon through 441 00:24:17,640 --> 00:24:21,359 Speaker 1: space that has mass nearby. The photon will not moving 442 00:24:21,359 --> 00:24:23,639 Speaker 1: what we consider to be a straight line, right, it 443 00:24:23,640 --> 00:24:26,840 Speaker 1: will find a path through this bent space that involves 444 00:24:26,880 --> 00:24:30,160 Speaker 1: basically curving. And this is what Einstein predicted with his theory, 445 00:24:30,160 --> 00:24:32,000 Speaker 1: and they and they saw it, you know. And you 446 00:24:32,040 --> 00:24:35,200 Speaker 1: can see in space it's called gravitational lensing. You can 447 00:24:35,200 --> 00:24:38,639 Speaker 1: see photons get bent by heavy objects. And it's because, 448 00:24:38,680 --> 00:24:42,000 Speaker 1: as you say, the heavy objects are bending space itself. Right, 449 00:24:42,040 --> 00:24:44,919 Speaker 1: It's not like gravity is pulling the photon because the 450 00:24:44,960 --> 00:24:47,840 Speaker 1: photon doesn't have any mass, right, that's right. The photon 451 00:24:47,920 --> 00:24:50,240 Speaker 1: doesn't have any mass, you know. So that's so that's 452 00:24:50,240 --> 00:24:53,720 Speaker 1: how it's different. Like gravity seems to affect things that 453 00:24:54,240 --> 00:24:56,960 Speaker 1: don't have sort of its fundamental property, you know, like 454 00:24:57,080 --> 00:25:00,960 Speaker 1: electromagantic forces can affect something that does not have an 455 00:25:00,960 --> 00:25:04,840 Speaker 1: electric charge. That gravity can affect things everything else. Right. Yeah, 456 00:25:04,880 --> 00:25:07,960 Speaker 1: that's a pretty deep insight there. I'm not bad for 457 00:25:07,960 --> 00:25:12,800 Speaker 1: a cartoonist at all. Yeah. Um, that's a fascinating to 458 00:25:12,840 --> 00:25:15,520 Speaker 1: think about. I think that's totally correct. Um. Yeah, And 459 00:25:15,560 --> 00:25:18,199 Speaker 1: so if gravity is instead of being a force, if 460 00:25:18,200 --> 00:25:21,320 Speaker 1: it's a way we change the shape of space itself, 461 00:25:21,359 --> 00:25:23,680 Speaker 1: then maybe that's why we don't have a quantum theory 462 00:25:23,720 --> 00:25:26,760 Speaker 1: of it. Right, And that's amazing and it's fantastic and 463 00:25:26,800 --> 00:25:29,760 Speaker 1: it's exciting um. And another reason why we have a 464 00:25:29,760 --> 00:25:33,240 Speaker 1: hard time bringing these two things together is that quantum mechanics, 465 00:25:33,520 --> 00:25:37,040 Speaker 1: the theory we've developed only works so far in flat space. 466 00:25:37,640 --> 00:25:40,760 Speaker 1: That is, if there's really heavy stuff nearby, we don't 467 00:25:40,760 --> 00:25:43,600 Speaker 1: know how to do those quantum calculations. We can basically 468 00:25:43,640 --> 00:25:46,400 Speaker 1: only do quantum mechanics in places where there isn't really 469 00:25:46,440 --> 00:25:50,680 Speaker 1: strong gravity. So wa, it's a quantum physics doesn't work 470 00:25:50,680 --> 00:25:54,280 Speaker 1: in reality basically, is that what you're saying, like, it 471 00:25:54,280 --> 00:25:58,000 Speaker 1: doesn't work in the space that we actually live in, Well, 472 00:25:58,000 --> 00:26:02,720 Speaker 1: it works basically everywhere except for those to black holes. Right. 473 00:26:02,880 --> 00:26:05,480 Speaker 1: You need to basically a black hole have enough gravity 474 00:26:05,560 --> 00:26:08,600 Speaker 1: to break down quantum mechanics, because it's when when space 475 00:26:08,640 --> 00:26:11,360 Speaker 1: gets really distorted that you start to see the effects 476 00:26:11,359 --> 00:26:14,600 Speaker 1: of gravity on space and and then it becomes comparable 477 00:26:14,680 --> 00:26:17,360 Speaker 1: to the strength of other stuff, and that's when that's 478 00:26:17,359 --> 00:26:20,400 Speaker 1: when quantum mechanics breaks down. Yeah, quantum quantum field theory 479 00:26:20,480 --> 00:26:24,480 Speaker 1: works basically what we call flat space, whereas gravity bends space. 480 00:26:29,080 --> 00:26:32,360 Speaker 1: So earlier when we categorize gravity as part of these 481 00:26:32,359 --> 00:26:35,600 Speaker 1: four fundamental forces, maybe that's just the wrong approach. Maybe, 482 00:26:35,600 --> 00:26:38,240 Speaker 1: you know, do you know what I mean? Like, maybe, um, 483 00:26:38,280 --> 00:26:41,080 Speaker 1: we shouldn't be categorizing these four things as is one 484 00:26:41,160 --> 00:26:45,080 Speaker 1: category of quote forces. That's right. It could be that 485 00:26:45,160 --> 00:26:46,960 Speaker 1: it could be that there is no quantum theory of 486 00:26:47,000 --> 00:26:49,880 Speaker 1: gravity as a fundamental force because it isn't one. Yeah, 487 00:26:49,920 --> 00:26:53,160 Speaker 1: and it's just a feature of space, right, Absolutely, that's 488 00:26:53,200 --> 00:26:56,720 Speaker 1: one possible explanation. But then we still need a way 489 00:26:56,720 --> 00:26:59,359 Speaker 1: to make quantum mechanics work in bent space, right, And 490 00:26:59,359 --> 00:27:03,040 Speaker 1: we still need understand how to make our theory of 491 00:27:03,080 --> 00:27:06,040 Speaker 1: general relativity play well with quantum mechanics, because we think 492 00:27:06,080 --> 00:27:09,560 Speaker 1: quantum mechanics describes the universe, right, and general relativity is 493 00:27:09,600 --> 00:27:13,640 Speaker 1: not a quantized theory. It's it's continuous, right. It treats 494 00:27:13,680 --> 00:27:17,480 Speaker 1: space and everything as if it's infinitely divisible. Right, it's 495 00:27:17,520 --> 00:27:19,400 Speaker 1: not a quantum theory all the fact that it came 496 00:27:19,400 --> 00:27:22,600 Speaker 1: about before quantum mechanics was even invented. And so while 497 00:27:22,720 --> 00:27:24,880 Speaker 1: the basic tenants of it how it distorts space are 498 00:27:24,880 --> 00:27:29,199 Speaker 1: probably correct, I been verified to zillion degrees of accuracy. Right, 499 00:27:29,280 --> 00:27:32,160 Speaker 1: it doesn't feel like it can be a fundamental description 500 00:27:32,200 --> 00:27:35,040 Speaker 1: of nature because it's not quantum mechanical. So like we 501 00:27:35,160 --> 00:27:37,280 Speaker 1: want to call it a force because it seems to 502 00:27:37,520 --> 00:27:40,600 Speaker 1: move things like all the other forces, but it's it. 503 00:27:40,680 --> 00:27:42,359 Speaker 1: Maybe it's not a force. Maybe it's just kind of 504 00:27:42,400 --> 00:27:46,440 Speaker 1: like a some other weird property of space. Yeah, exactly. 505 00:27:46,720 --> 00:27:48,400 Speaker 1: You know, maybe we've been trying to put a round 506 00:27:48,400 --> 00:27:52,760 Speaker 1: peg into a square hole all these years, a gravity 507 00:27:52,760 --> 00:27:56,560 Speaker 1: peg and a quantum hole. That's right, that's right. And 508 00:27:56,600 --> 00:27:58,360 Speaker 1: there are other ways that people are trying to solve 509 00:27:58,400 --> 00:28:01,199 Speaker 1: this problem. Like one way is thinking that maybe gravity 510 00:28:01,320 --> 00:28:03,320 Speaker 1: is a fundamental force, but it just works a little 511 00:28:03,320 --> 00:28:06,360 Speaker 1: bit differently from the other forces. For example, people think 512 00:28:06,400 --> 00:28:09,959 Speaker 1: about how the universe might have additional spatial dimensions, you know, 513 00:28:10,040 --> 00:28:11,920 Speaker 1: like instead of just being able to move in three 514 00:28:11,960 --> 00:28:14,960 Speaker 1: spain directions, maybe there's like four or five six dimensions 515 00:28:14,960 --> 00:28:17,080 Speaker 1: that you can move in. And folks who are interested 516 00:28:17,080 --> 00:28:20,440 Speaker 1: in that should listen to our podcast on extra dimensions. No, yeah, 517 00:28:20,440 --> 00:28:22,359 Speaker 1: we did a whole episode on extra dimensions, but we 518 00:28:22,359 --> 00:28:24,840 Speaker 1: didn't start of get into this particular topic. Um, so 519 00:28:24,960 --> 00:28:29,399 Speaker 1: tell us how extra dimensions might explain why gravity is 520 00:28:29,400 --> 00:28:32,520 Speaker 1: so weak. Yeah. The idea is that maybe gravity isn't 521 00:28:32,520 --> 00:28:35,160 Speaker 1: so weak. Maybe gravity is just as strong as all 522 00:28:35,200 --> 00:28:38,800 Speaker 1: the other forces. But if there's a whole other set 523 00:28:38,840 --> 00:28:42,680 Speaker 1: of dimensions out there, there's ways directions that think can move. 524 00:28:43,160 --> 00:28:45,600 Speaker 1: It might be that gravity is the only thing that 525 00:28:45,680 --> 00:28:48,320 Speaker 1: feels those dimensions, right. It might be that those dimensions 526 00:28:48,320 --> 00:28:51,640 Speaker 1: are invisible to electromagnetism and to the weak force into 527 00:28:51,640 --> 00:28:55,000 Speaker 1: the strong force, but visible to gravity. And what that 528 00:28:55,080 --> 00:28:58,480 Speaker 1: means is that gravity might be basically leaking out into 529 00:28:58,480 --> 00:29:01,720 Speaker 1: those other dimensions. Know, we talked about how the farther 530 00:29:01,840 --> 00:29:03,880 Speaker 1: your way you get from something, the weaker the forces. 531 00:29:03,960 --> 00:29:07,400 Speaker 1: So like Mercury feels the force of the Sun's gravity 532 00:29:07,480 --> 00:29:10,320 Speaker 1: much more strongly than Pluto does. Right, irrelevant of whether 533 00:29:10,360 --> 00:29:12,040 Speaker 1: or not you call it a planet, it doesn't feel 534 00:29:12,080 --> 00:29:15,160 Speaker 1: gravity very strongly. And that's because it's further from the Sun, right. 535 00:29:15,200 --> 00:29:17,240 Speaker 1: I mean that goes like one over our squared or 536 00:29:17,320 --> 00:29:20,240 Speaker 1: r as the distance. It's one of our squared because 537 00:29:20,280 --> 00:29:23,280 Speaker 1: we have three dimensions. If we had six dimensions, it 538 00:29:23,280 --> 00:29:26,600 Speaker 1: would be one over our five, right, which falls much 539 00:29:26,640 --> 00:29:31,520 Speaker 1: more rapidly. So if there are additional dimensions out there, okay, 540 00:29:31,760 --> 00:29:34,480 Speaker 1: and only gravity feels them, think that might be the 541 00:29:34,560 --> 00:29:38,800 Speaker 1: reason why gravitational force fall so quickly. Maybe gravity is 542 00:29:38,840 --> 00:29:40,800 Speaker 1: actually just as strong as everything else when you get 543 00:29:40,800 --> 00:29:43,960 Speaker 1: really really close. But then these extra dimensions exist, and 544 00:29:44,080 --> 00:29:48,680 Speaker 1: most of gravity leaks out into those other dimensions, sort 545 00:29:48,680 --> 00:29:51,400 Speaker 1: of like between you and me, there's not just the 546 00:29:51,440 --> 00:29:54,040 Speaker 1: three dimensions between you and me. May there are other 547 00:29:54,200 --> 00:29:57,400 Speaker 1: secret hidden spaces kind of between you and me or 548 00:29:57,440 --> 00:30:02,080 Speaker 1: these other dimensions exactly, other ways for gravity to spread out. Right, 549 00:30:02,400 --> 00:30:04,440 Speaker 1: So gravity would be like just as strong as all 550 00:30:04,480 --> 00:30:07,680 Speaker 1: the other forces, but it's just flexing its muscles in 551 00:30:07,760 --> 00:30:11,720 Speaker 1: these other spaces that we can't see or feel exactly. 552 00:30:11,720 --> 00:30:13,440 Speaker 1: It's like, you know, if somebody's at the center of 553 00:30:13,440 --> 00:30:16,040 Speaker 1: a crowd and they let go a really stinky far right. 554 00:30:16,120 --> 00:30:18,440 Speaker 1: The people next to them they smell it strongly, and 555 00:30:18,440 --> 00:30:20,960 Speaker 1: the people further away they smell it much more weakly, 556 00:30:21,000 --> 00:30:23,479 Speaker 1: and people outside don't smell it at all. Right, now, 557 00:30:23,560 --> 00:30:27,280 Speaker 1: imagine really suddenly, but let's let's let's go with it. Hey, 558 00:30:27,280 --> 00:30:29,640 Speaker 1: I'm trying to make this successible. You know, this is 559 00:30:29,680 --> 00:30:34,880 Speaker 1: something everybody going to appreciate. Trying to make it. And 560 00:30:35,040 --> 00:30:37,040 Speaker 1: but if there was somewhere else for that fart to go, 561 00:30:37,240 --> 00:30:39,680 Speaker 1: you know, if it could move not just sideways, but 562 00:30:39,720 --> 00:30:41,960 Speaker 1: also could float up right. So you had a really 563 00:30:42,000 --> 00:30:44,520 Speaker 1: tall room in the floor, fart floated up, then people 564 00:30:44,520 --> 00:30:46,440 Speaker 1: wouldn't feel it as much because most of the fart 565 00:30:46,440 --> 00:30:50,000 Speaker 1: would dissipate into the upper corners of the room. And 566 00:30:50,120 --> 00:30:52,240 Speaker 1: so gravity might be the same way. It might be that, 567 00:30:52,440 --> 00:30:55,040 Speaker 1: you know, for the first millimeter, so the first centimeter, 568 00:30:55,160 --> 00:30:59,160 Speaker 1: so gravity gets very weak, very quickly, it falls off 569 00:30:59,280 --> 00:31:01,840 Speaker 1: really wrap ly, and that then you know, a normal 570 00:31:01,880 --> 00:31:04,560 Speaker 1: distances like a meter or ten ms or whatever, you 571 00:31:04,600 --> 00:31:07,640 Speaker 1: don't feel those other dimensions anymore because other other dimensions 572 00:31:07,640 --> 00:31:10,720 Speaker 1: only activated really really short distances. This is the theory 573 00:31:10,720 --> 00:31:12,720 Speaker 1: people came up with, and we don't know if it's real. 574 00:31:12,800 --> 00:31:14,840 Speaker 1: You know, we've tested it so far. It seems like 575 00:31:14,880 --> 00:31:19,080 Speaker 1: gravity works the same way um for galactic scales and 576 00:31:19,120 --> 00:31:21,760 Speaker 1: for Earth scales, and for microscopic scales. It seems to 577 00:31:21,800 --> 00:31:24,440 Speaker 1: always fall off at the same rate as a function 578 00:31:24,480 --> 00:31:26,880 Speaker 1: of distance. So nobody's ever seen any evidence of these 579 00:31:26,880 --> 00:31:29,560 Speaker 1: extra dimensions. But it's a fascinating theory and it's a 580 00:31:29,880 --> 00:31:31,080 Speaker 1: you know, it's one that would give a kind of 581 00:31:31,080 --> 00:31:34,520 Speaker 1: a natural explanation for why gravity would fall off so 582 00:31:34,600 --> 00:31:37,080 Speaker 1: quickly and why gravity is so weak it wouldn't explain 583 00:31:37,080 --> 00:31:39,640 Speaker 1: all these other things. But people sort of try to 584 00:31:39,720 --> 00:31:42,840 Speaker 1: use gravity to see if there are other dimensions, right, Yeah, 585 00:31:42,920 --> 00:31:45,040 Speaker 1: that's right. It would be a really cool clue, right if. 586 00:31:45,480 --> 00:31:48,240 Speaker 1: And and that's a fascinating way that science has done. 587 00:31:48,280 --> 00:31:50,560 Speaker 1: You know, you try to look at everything around you 588 00:31:50,600 --> 00:31:52,680 Speaker 1: and see if you can fit it all into one framework, 589 00:31:52,920 --> 00:31:55,400 Speaker 1: like can I use this one set of ideas to 590 00:31:55,440 --> 00:32:01,840 Speaker 1: describe everything canto one part of concepts? That's right, and 591 00:32:02,000 --> 00:32:09,040 Speaker 1: my far theory of you in the universe. Um, The 592 00:32:09,080 --> 00:32:11,080 Speaker 1: best possible way I think to unravel this is to 593 00:32:11,120 --> 00:32:14,000 Speaker 1: actually go visit a black hole, because a quantum mechanics 594 00:32:14,000 --> 00:32:17,240 Speaker 1: and general relativity tell you very different things about what's 595 00:32:17,280 --> 00:32:20,200 Speaker 1: happening inside a black hole. Right, As we said before, 596 00:32:20,600 --> 00:32:23,600 Speaker 1: general relativity tells you it's an infinitesimal dot of of 597 00:32:23,640 --> 00:32:27,200 Speaker 1: almost infinite density. Quanto mechanics says, you know, the universe 598 00:32:27,240 --> 00:32:30,160 Speaker 1: is quantized first of all, so you can't have infinitesimal 599 00:32:30,280 --> 00:32:33,080 Speaker 1: dots um. And also this sort of a minimum size 600 00:32:33,160 --> 00:32:35,640 Speaker 1: to stuff, right, and you can't have all that stuff 601 00:32:35,680 --> 00:32:38,680 Speaker 1: compressed in such a tiny little area. And so if 602 00:32:38,680 --> 00:32:40,480 Speaker 1: you could see inside a black hole, you would learn 603 00:32:40,520 --> 00:32:42,840 Speaker 1: a lot about gravity. So what would be the plan. 604 00:32:42,880 --> 00:32:45,200 Speaker 1: You would go into a black hole. You would observe 605 00:32:45,280 --> 00:32:48,640 Speaker 1: and discover how the universe works, and then and then 606 00:32:48,640 --> 00:32:50,720 Speaker 1: you'd be stuck there. That's right. They would have to 607 00:32:50,760 --> 00:32:53,160 Speaker 1: send your Nobel Prize into the black hole. Act, which is, 608 00:32:53,160 --> 00:32:57,000 Speaker 1: assume you'd figure it out, and the Nobel Prize into 609 00:32:57,040 --> 00:33:00,840 Speaker 1: space into the black hole. Congratulate for anybody who's listening. 610 00:33:00,840 --> 00:33:03,360 Speaker 1: Please do not go into a black hole. Please, please 611 00:33:03,400 --> 00:33:04,960 Speaker 1: do not go into a black hole. But you know, 612 00:33:05,000 --> 00:33:07,040 Speaker 1: we don't need to visit black holes. We could try 613 00:33:07,040 --> 00:33:09,280 Speaker 1: to create them here on Earth. That sounds like a 614 00:33:09,360 --> 00:33:12,040 Speaker 1: great idea. Yeah, doesn that sounds like a great idea. 615 00:33:12,080 --> 00:33:16,840 Speaker 1: I mean I'm excited make a quality. Yeah, let's create 616 00:33:16,880 --> 00:33:19,880 Speaker 1: a black hole and study here. Right, Um, if gravity 617 00:33:19,920 --> 00:33:22,440 Speaker 1: gets really really powerful when you get two really short 618 00:33:22,480 --> 00:33:25,320 Speaker 1: distances because of this extra dimension theory, then it might 619 00:33:25,320 --> 00:33:27,640 Speaker 1: be that if you shoot two protons together really really 620 00:33:27,680 --> 00:33:29,240 Speaker 1: hard and they get really really close to each other, 621 00:33:29,480 --> 00:33:32,280 Speaker 1: that you can create a super duper mini extra cute, 622 00:33:32,360 --> 00:33:34,640 Speaker 1: little fuzzy black hole. Right. I'm trying to make it 623 00:33:34,680 --> 00:33:37,400 Speaker 1: sound like a cozy thing. Yeah, you're trying to sell 624 00:33:37,440 --> 00:33:45,400 Speaker 1: it and so um, before we turned on the Large 625 00:33:45,440 --> 00:33:48,120 Speaker 1: he collided about ten years ago, people thought maybe by 626 00:33:48,120 --> 00:33:50,960 Speaker 1: smashing these protons together we could actually create black holes 627 00:33:50,960 --> 00:33:53,240 Speaker 1: and we could study them. We can reveal the deep 628 00:33:53,240 --> 00:33:57,800 Speaker 1: secrets of gravity, right um. So, then the idea would 629 00:33:57,800 --> 00:33:59,360 Speaker 1: be to try to make them at the Large Hattern 630 00:33:59,400 --> 00:34:02,360 Speaker 1: Collider and just kind of see what happens, like, does 631 00:34:02,400 --> 00:34:05,400 Speaker 1: it tell us something about gravity or quantum physics at 632 00:34:05,400 --> 00:34:08,840 Speaker 1: the same time exactly by seeing how often they're made 633 00:34:08,920 --> 00:34:11,120 Speaker 1: and how strong they are and what they turned into 634 00:34:11,200 --> 00:34:14,439 Speaker 1: when they decay, we can understand something about the way 635 00:34:14,480 --> 00:34:17,200 Speaker 1: black holes work, and that would have been really powerful. 636 00:34:17,239 --> 00:34:20,359 Speaker 1: But unfortunately or fortunately, depending on how you feel about 637 00:34:20,400 --> 00:34:22,520 Speaker 1: black holes, we haven't made any black holes at the 638 00:34:22,560 --> 00:34:25,920 Speaker 1: Large Hadron Collider that we've discovered that you but maybe 639 00:34:26,200 --> 00:34:29,040 Speaker 1: isn't it true that maybe you've made them but they evaporate. Yes, 640 00:34:29,080 --> 00:34:31,239 Speaker 1: these black holes would be very short lived, but you know, 641 00:34:31,320 --> 00:34:33,279 Speaker 1: everything we make at the Large Hadron Collider is really 642 00:34:33,320 --> 00:34:35,440 Speaker 1: short lived. These things last we like tend the negative 643 00:34:35,480 --> 00:34:38,239 Speaker 1: thirty seconds or tend the negative twenty three seconds. We're 644 00:34:38,280 --> 00:34:40,480 Speaker 1: pretty good at seeing short lived stuff because it usually 645 00:34:40,480 --> 00:34:43,200 Speaker 1: blows up into other things. And a black hole would 646 00:34:43,239 --> 00:34:45,759 Speaker 1: have a really unusual signature in our detective it would 647 00:34:45,800 --> 00:34:48,360 Speaker 1: be pretty clear to see if we had made them. Okay, 648 00:34:48,800 --> 00:34:52,160 Speaker 1: but short of going into a black hole or detecting 649 00:34:52,239 --> 00:34:56,040 Speaker 1: farts and extra dimensions, we may not know in the 650 00:34:56,080 --> 00:34:59,520 Speaker 1: near future what what makes gravity so different? That's right, 651 00:34:59,560 --> 00:35:01,880 Speaker 1: it's going to take some work. I mean. The other direction, 652 00:35:02,120 --> 00:35:04,560 Speaker 1: is theoretical, is to build up a theory of quantum 653 00:35:04,560 --> 00:35:07,560 Speaker 1: gravity sort of from the bottom up, like like, start 654 00:35:07,600 --> 00:35:10,120 Speaker 1: from the beauty of math and physics and then try 655 00:35:10,200 --> 00:35:13,799 Speaker 1: to build it up to our level exactly. And that's 656 00:35:13,960 --> 00:35:15,680 Speaker 1: that's a wonderful way to do, is to say, like, 657 00:35:15,880 --> 00:35:18,720 Speaker 1: maybe the universe works in this way, that's most basic 658 00:35:18,800 --> 00:35:21,520 Speaker 1: fundamental nature, and build it up from there and see 659 00:35:21,560 --> 00:35:23,960 Speaker 1: if you can describe the universe that we see around us. 660 00:35:25,400 --> 00:35:28,560 Speaker 1: All right, Well, that's um, it's pretty shocking to think 661 00:35:28,600 --> 00:35:31,400 Speaker 1: gravity it's such a place, such a big role in 662 00:35:31,440 --> 00:35:35,000 Speaker 1: our lives, and yet it's it's like the the weakling 663 00:35:35,040 --> 00:35:37,880 Speaker 1: in the universe, right, It's like, imagine, imagine if if 664 00:35:37,920 --> 00:35:41,400 Speaker 1: gravity was stronger, life would beat a lot more chaotic, 665 00:35:41,520 --> 00:35:44,040 Speaker 1: right and crazy? Yeah, exactly. We would be closer to 666 00:35:44,080 --> 00:35:47,280 Speaker 1: the Sun and everything would feel more intense. It's fascinating 667 00:35:47,320 --> 00:35:49,920 Speaker 1: to me that gravity has been a mystery to physics 668 00:35:49,920 --> 00:35:51,720 Speaker 1: for hundreds of years. I mean, it was the focus 669 00:35:51,719 --> 00:35:54,640 Speaker 1: of Isaac Newton's studies, you know, like hundreds of years 670 00:35:54,640 --> 00:35:57,600 Speaker 1: ago people working on gravity. And still today, even though 671 00:35:57,600 --> 00:36:00,480 Speaker 1: we've made so much progress in terms of gravity, we 672 00:36:00,560 --> 00:36:02,960 Speaker 1: still have so much, so many basic questions about it 673 00:36:02,960 --> 00:36:04,600 Speaker 1: that we don't we don't know the answers to, not 674 00:36:04,640 --> 00:36:07,279 Speaker 1: even really beginning of how to answer them to meet. 675 00:36:07,280 --> 00:36:10,360 Speaker 1: That's fascinating. Gravity is such a rich source of mystery 676 00:36:10,640 --> 00:36:14,399 Speaker 1: for physics and for everybody. Wow, alright, cool, I think 677 00:36:14,400 --> 00:36:17,680 Speaker 1: it's maybe time to push down this question. Thanks for 678 00:36:17,760 --> 00:36:28,600 Speaker 1: joining us. If you still have a question after listening 679 00:36:28,600 --> 00:36:31,680 Speaker 1: to all these explanations, please drop us a line. We'd 680 00:36:31,760 --> 00:36:34,560 Speaker 1: love to hear from you. You can find us at Facebook, Twitter, 681 00:36:34,680 --> 00:36:38,319 Speaker 1: and Instagram at Daniel and Jorge That's one word, or 682 00:36:38,440 --> 00:36:51,120 Speaker 1: email us at Feedback at Daniel and Jorge dot com.