1 00:00:08,000 --> 00:00:10,240 Speaker 1: Hey, Daniel, have you guys figured out how to make 2 00:00:10,320 --> 00:00:12,680 Speaker 1: quantum mechanics and gravity work together? 3 00:00:12,800 --> 00:00:13,320 Speaker 2: Yet? Oh? 4 00:00:13,440 --> 00:00:15,440 Speaker 3: Hit me hard with a nasty question right off the bat. 5 00:00:15,520 --> 00:00:18,599 Speaker 3: Huh well, unfortunately we haven't figured it out yet. 6 00:00:19,160 --> 00:00:21,080 Speaker 1: Well what have you guys been working on and how 7 00:00:21,079 --> 00:00:22,279 Speaker 1: long have you been working on it? 8 00:00:22,440 --> 00:00:23,279 Speaker 4: Like decades? 9 00:00:24,280 --> 00:00:26,360 Speaker 3: More than one hundred years? Actually? 10 00:00:26,520 --> 00:00:29,120 Speaker 1: Uh? Well, and I thought I was a little bit 11 00:00:29,160 --> 00:00:30,680 Speaker 1: behind on my deadlines. 12 00:00:30,760 --> 00:00:33,239 Speaker 4: So you know how long you think it's going to take? 13 00:00:33,280 --> 00:00:37,440 Speaker 1: Another weekend? Another thousand years? Can I get it in 14 00:00:37,479 --> 00:00:38,120 Speaker 1: by monday? 15 00:00:40,200 --> 00:00:42,240 Speaker 3: You know? The only progress we've really made is coming 16 00:00:42,320 --> 00:00:44,200 Speaker 3: up with some long, confusing names for. 17 00:00:44,120 --> 00:00:47,720 Speaker 1: It, like Mississippi or quantum gravity. 18 00:00:49,320 --> 00:00:51,280 Speaker 3: No, that would be much too clear. 19 00:00:51,400 --> 00:00:55,200 Speaker 1: Okay, like gravito, quantum field, hydrodynamically. 20 00:00:56,760 --> 00:00:59,080 Speaker 3: I think you should be a physicist, Katie. You have 21 00:00:59,160 --> 00:00:59,880 Speaker 3: the knack for it. 22 00:01:00,080 --> 00:01:02,280 Speaker 1: I know how to throw a ball and look at 23 00:01:02,320 --> 00:01:04,800 Speaker 1: it go up and come down, So I'm already halfway there. 24 00:01:20,319 --> 00:01:23,120 Speaker 3: Hi. I'm Daniel. I'm a particle physicist and a professor 25 00:01:23,200 --> 00:01:26,200 Speaker 3: at UC Irvine, and I desperately want to know the 26 00:01:26,319 --> 00:01:28,120 Speaker 3: underlying rules of the universe. 27 00:01:28,480 --> 00:01:31,480 Speaker 1: I am Katie Golden. I am not a particle physicist. 28 00:01:31,560 --> 00:01:35,520 Speaker 1: I host a podcast about animals, but that doesn't mean 29 00:01:35,800 --> 00:01:39,680 Speaker 1: that I couldn't maybe try to smash quantum mechanics and 30 00:01:39,760 --> 00:01:42,800 Speaker 1: gravity together if you give me a government grant. 31 00:01:44,680 --> 00:01:47,440 Speaker 3: I think everybody who's not a particle physicist should introduce 32 00:01:47,480 --> 00:01:50,880 Speaker 3: themselves that way. Hi, I'm Sally. I'm not a particle physicist. 33 00:01:50,920 --> 00:01:52,200 Speaker 4: I think that makes the most sense. 34 00:01:54,640 --> 00:01:56,600 Speaker 3: In that case, I should start off by listing all 35 00:01:56,600 --> 00:01:58,960 Speaker 3: the things that I'm not every time I introduce myself 36 00:01:59,000 --> 00:02:01,760 Speaker 3: to somebody. I'm not an Olympic gymnast. I'm not a 37 00:02:01,760 --> 00:02:03,040 Speaker 3: Wall Street trader dot dot. 38 00:02:03,240 --> 00:02:05,360 Speaker 4: I am not a hot dog eating champion. 39 00:02:05,600 --> 00:02:11,600 Speaker 3: Yet we can all aspire to stuff well. Welcome to 40 00:02:11,639 --> 00:02:14,800 Speaker 3: the podcast Daniel and Jorge Explain the Universe, a production 41 00:02:14,880 --> 00:02:18,760 Speaker 3: of iHeartRadio in which we aspire to be particle physicists. 42 00:02:19,080 --> 00:02:21,880 Speaker 3: We all want to understand the way the universe works. 43 00:02:21,880 --> 00:02:24,280 Speaker 3: We all want to figure it out, to zoom down 44 00:02:24,320 --> 00:02:27,200 Speaker 3: to the tiniest little bits of the universe, the basic 45 00:02:27,280 --> 00:02:30,440 Speaker 3: building blocks and the rules that tertangle them, and zoom 46 00:02:30,440 --> 00:02:32,760 Speaker 3: out from that picture to understand how it all comes 47 00:02:32,760 --> 00:02:36,040 Speaker 3: together to make our amazing hour Bonkers are wonderful, our 48 00:02:36,160 --> 00:02:37,600 Speaker 3: delicious universe. 49 00:02:37,960 --> 00:02:43,000 Speaker 1: Yeah, like a nice stew of concepts all mingled up 50 00:02:43,040 --> 00:02:43,800 Speaker 1: in the stars. 51 00:02:43,880 --> 00:02:46,200 Speaker 4: So yeah, I mean it is interesting. 52 00:02:45,760 --> 00:02:48,640 Speaker 1: Because I think we've talked a little bit on the 53 00:02:48,639 --> 00:02:51,040 Speaker 1: times that I've been on the show about quantum mechanics. 54 00:02:51,040 --> 00:02:54,120 Speaker 1: We've talked about gravity, We've talked about sort of this 55 00:02:54,320 --> 00:02:59,320 Speaker 1: distinction between the physics involved in the really tiny and 56 00:02:59,520 --> 00:03:02,520 Speaker 1: the really huge, and how it's a bit of a 57 00:03:02,639 --> 00:03:04,520 Speaker 1: puzzle to fit those together. 58 00:03:04,960 --> 00:03:08,120 Speaker 3: Yeah, the basic strategy of physics has always been to 59 00:03:08,280 --> 00:03:10,880 Speaker 3: zoom down to the littlest bits of the universe to 60 00:03:10,880 --> 00:03:14,320 Speaker 3: try to understand them, and then hope that we can carefully, 61 00:03:14,480 --> 00:03:17,440 Speaker 3: one step at a time, zoom out and figure out 62 00:03:17,600 --> 00:03:20,680 Speaker 3: how those things come together to make our world. You know, 63 00:03:20,760 --> 00:03:23,799 Speaker 3: how electrons and protons come together to make atoms, and 64 00:03:23,840 --> 00:03:27,080 Speaker 3: atoms come together to make molecules, and molecules come together 65 00:03:27,120 --> 00:03:29,919 Speaker 3: to make proteins, and proteins come together to make steak 66 00:03:29,960 --> 00:03:32,040 Speaker 3: and ice cream and all the delicious things that you eat. 67 00:03:32,320 --> 00:03:35,520 Speaker 3: That's sort of like reductionist approach. We zoom down and 68 00:03:35,560 --> 00:03:38,400 Speaker 3: then one at a time step back up to understand 69 00:03:38,400 --> 00:03:41,160 Speaker 3: our world. Has long been the approach we wanted to 70 00:03:41,200 --> 00:03:43,760 Speaker 3: take to understand the universe, and that's worked for lots 71 00:03:43,800 --> 00:03:45,840 Speaker 3: of stuff, like the way we understand ice cream and 72 00:03:45,880 --> 00:03:48,560 Speaker 3: blueberries and steak and goats and all that stuff. But 73 00:03:48,600 --> 00:03:51,000 Speaker 3: you're right, Katie, there's one big thing that it hasn't 74 00:03:51,080 --> 00:03:54,440 Speaker 3: been able to explain, maybe the biggest, most important thing 75 00:03:54,480 --> 00:03:58,400 Speaker 3: that shapes our universe, and that's gravity. How everything seems 76 00:03:58,400 --> 00:04:01,440 Speaker 3: to attract itself or how things flow through space time. 77 00:04:01,880 --> 00:04:04,480 Speaker 3: We still don't understand how that bubbles up from the 78 00:04:04,520 --> 00:04:05,840 Speaker 3: tiniest little bits of. 79 00:04:05,840 --> 00:04:09,960 Speaker 1: The universe because gravity is sort of, I guess, like 80 00:04:10,000 --> 00:04:13,080 Speaker 1: a big force that we observe. So like you know, 81 00:04:13,120 --> 00:04:16,360 Speaker 1: you feel gravity on a planet. Maybe you and I 82 00:04:16,560 --> 00:04:19,520 Speaker 1: have our own gravitational pull, but it's much weaker than 83 00:04:19,560 --> 00:04:22,400 Speaker 1: a planet, so we're not going to notice it. But 84 00:04:22,760 --> 00:04:25,839 Speaker 1: is gravity something you can really measure much when you 85 00:04:25,920 --> 00:04:28,640 Speaker 1: get really small, like say you're looking at particles, Like 86 00:04:28,680 --> 00:04:31,880 Speaker 1: does a particle have its own gravity? Or can you 87 00:04:31,920 --> 00:04:35,560 Speaker 1: even measure gravity of say like a neutron or a 88 00:04:35,600 --> 00:04:37,040 Speaker 1: proton or an electron. 89 00:04:37,240 --> 00:04:40,400 Speaker 3: Yeah, that's exactly the puzzle. On a theoretical sense. We 90 00:04:40,480 --> 00:04:42,960 Speaker 3: don't know how to stitch these two things together, and 91 00:04:43,000 --> 00:04:46,320 Speaker 3: we'll talk about that more during this podcast. But even 92 00:04:46,360 --> 00:04:50,200 Speaker 3: more frustrating in experimental sense, we can't even see what 93 00:04:50,240 --> 00:04:53,560 Speaker 3: the universe does. Basically, the job of physics is to 94 00:04:53,640 --> 00:04:56,440 Speaker 3: explain what is the universe doing, what's happening out there, 95 00:04:56,480 --> 00:04:59,240 Speaker 3: and why does it make sense? And the first step 96 00:04:59,279 --> 00:05:01,479 Speaker 3: there is to see what's happening in the universe. And 97 00:05:01,520 --> 00:05:02,880 Speaker 3: so the first thing you want to do if you 98 00:05:03,120 --> 00:05:06,200 Speaker 3: want to explain the gravity of little particles, the quantum 99 00:05:06,240 --> 00:05:10,080 Speaker 3: mechanical understanding of gravity is to see gravity operating on 100 00:05:10,160 --> 00:05:13,560 Speaker 3: little particles. That's basically what you're asking. And the challenge 101 00:05:13,600 --> 00:05:16,839 Speaker 3: there is that gravity is so dang weak compared to 102 00:05:16,880 --> 00:05:20,120 Speaker 3: the other forces of electromagnetism, even the weak force and 103 00:05:20,160 --> 00:05:23,680 Speaker 3: definitely the strong force, Gravity is like a bajillion zillion 104 00:05:23,800 --> 00:05:27,680 Speaker 3: quintillion times weaker, which is why, for example, like a 105 00:05:27,760 --> 00:05:31,120 Speaker 3: simple fridge magnet can overpower the gravity of the Earth 106 00:05:31,400 --> 00:05:34,000 Speaker 3: and hold your recipe against your fridge or your pictures 107 00:05:34,000 --> 00:05:37,000 Speaker 3: of your kids and their cousins. It's not hard to 108 00:05:37,120 --> 00:05:40,200 Speaker 3: overcome the gravity of an entire planet with a tiny 109 00:05:40,279 --> 00:05:43,640 Speaker 3: little bit of electromagnetism. And so when you're looking at 110 00:05:43,640 --> 00:05:46,880 Speaker 3: a tiny particle, a proton or a neutron, its gravity 111 00:05:46,920 --> 00:05:50,720 Speaker 3: is basically zero. It's so hard to measure. The smallest 112 00:05:50,720 --> 00:05:53,840 Speaker 3: thing we've ever measured the gravity of is something like 113 00:05:53,880 --> 00:05:56,400 Speaker 3: on the order of a gram, you know, which means 114 00:05:56,400 --> 00:06:00,080 Speaker 3: it has like ten to twenty particles in it. We 115 00:06:00,120 --> 00:06:04,200 Speaker 3: are nowhere close to being able to see gravity operate 116 00:06:04,320 --> 00:06:07,200 Speaker 3: on particles so that we can then try to explain 117 00:06:07,279 --> 00:06:08,120 Speaker 3: how it all works. 118 00:06:08,720 --> 00:06:12,680 Speaker 1: That seems kind of hard because like science is mostly 119 00:06:12,760 --> 00:06:17,560 Speaker 1: about say, either direct observation or setting up an experiment. 120 00:06:17,920 --> 00:06:20,680 Speaker 4: So if you can't even see it happening. 121 00:06:20,839 --> 00:06:23,520 Speaker 1: Or figure out how to observe it in particles, how 122 00:06:23,520 --> 00:06:26,400 Speaker 1: can you ever figure out how it works on such 123 00:06:26,400 --> 00:06:27,200 Speaker 1: a small scale. 124 00:06:27,800 --> 00:06:30,560 Speaker 3: Yeah, great question. Well one is you don't give up. 125 00:06:30,600 --> 00:06:37,560 Speaker 4: Oh I was I was gonna go for Just give up, never. 126 00:06:37,400 --> 00:06:41,479 Speaker 3: Give up, never give it. People are doing these incredible experiments. 127 00:06:41,480 --> 00:06:45,039 Speaker 3: It's really an amazing accomplishment to figure out how to 128 00:06:45,200 --> 00:06:47,680 Speaker 3: test gravity on the smaller and smaller things. And there's 129 00:06:47,680 --> 00:06:50,280 Speaker 3: this history getting all the way back to like Cavendish 130 00:06:50,320 --> 00:06:53,480 Speaker 3: torsion experiments of lead balls a weigh a few pounds, 131 00:06:53,680 --> 00:06:56,720 Speaker 3: down to smaller objects and smaller objects, and very recently 132 00:06:56,960 --> 00:06:59,359 Speaker 3: down to stuff like smaller than a raisin, you know, 133 00:06:59,360 --> 00:07:02,360 Speaker 3: a few grains of sand of material, and I really 134 00:07:02,360 --> 00:07:05,719 Speaker 3: want to underscore that there's a special scientific skill there. 135 00:07:05,880 --> 00:07:10,480 Speaker 3: It's not like mathematics or genius insight into philosophy. It's 136 00:07:10,640 --> 00:07:14,240 Speaker 3: experimental bravura, you know. It's what Jorge might call engineering. 137 00:07:14,640 --> 00:07:17,360 Speaker 3: It's like figuring out how to make your experimental system 138 00:07:17,440 --> 00:07:20,240 Speaker 3: so quiet and so clean and so pristine that you 139 00:07:20,280 --> 00:07:23,360 Speaker 3: can force the universe to reveal one of its secrets. 140 00:07:23,680 --> 00:07:26,320 Speaker 3: It's a really special skill in science. And so those 141 00:07:26,360 --> 00:07:28,880 Speaker 3: folks are working hard and drilling down. But yeah, they're 142 00:07:28,920 --> 00:07:32,200 Speaker 3: like twenty orders of magnitude away from figuring it out, 143 00:07:32,200 --> 00:07:34,240 Speaker 3: so it's going to be a while. The other thing is, 144 00:07:34,280 --> 00:07:36,520 Speaker 3: you could, you know, try to visit a black hole. 145 00:07:36,880 --> 00:07:39,280 Speaker 3: Inside a black hole. We think that gravity and quant 146 00:07:39,320 --> 00:07:42,800 Speaker 3: mechanics are both relevant because obviously there's strong gravity, but 147 00:07:42,840 --> 00:07:46,480 Speaker 3: also things are squished really really small at the singularity 148 00:07:46,520 --> 00:07:50,320 Speaker 3: inside the black hole. Of course, that's inside the black 149 00:07:50,320 --> 00:07:53,119 Speaker 3: hole beyond the event horizon. So we still haven't figured 150 00:07:53,120 --> 00:07:54,040 Speaker 3: out how to probe that. 151 00:07:54,440 --> 00:07:57,080 Speaker 1: Yeah, we've talked about this. It is not in the 152 00:07:57,120 --> 00:08:00,960 Speaker 1: budget to go to a black just yet. 153 00:08:01,680 --> 00:08:03,520 Speaker 3: No, so instead you might want to make your own 154 00:08:03,560 --> 00:08:06,040 Speaker 3: black hole and then study the patterns of its hawking 155 00:08:06,120 --> 00:08:08,600 Speaker 3: radiation to try to get some clues as to what 156 00:08:08,720 --> 00:08:11,760 Speaker 3: might be inside of it. But nobody succeeded in making 157 00:08:11,800 --> 00:08:13,400 Speaker 3: a black hole yet, and if they did, it might 158 00:08:13,400 --> 00:08:16,840 Speaker 3: destroy the Earth, and so there are some questions there. 159 00:08:17,480 --> 00:08:20,960 Speaker 3: So while the experimental side is super tooper frustrating, we 160 00:08:21,000 --> 00:08:24,800 Speaker 3: can try to make some progress on the theoretical side, thinking 161 00:08:24,840 --> 00:08:29,200 Speaker 3: deeply about the universe, eating special mushrooms and having insights 162 00:08:29,280 --> 00:08:33,480 Speaker 3: about you know, connections and mathematical symmetries between these two ideas, 163 00:08:33,559 --> 00:08:36,000 Speaker 3: to look for links, to look for connections, to look 164 00:08:36,040 --> 00:08:38,800 Speaker 3: for ways to fit them together in our minds that 165 00:08:38,920 --> 00:08:41,080 Speaker 3: might give us some new clues as to how to 166 00:08:41,120 --> 00:08:44,560 Speaker 3: bridge these two fundamental pillars of modern physics. 167 00:08:44,800 --> 00:08:49,000 Speaker 1: Now, do you get university funding for mushroom tripping in 168 00:08:49,080 --> 00:08:51,640 Speaker 1: the sake of theoretical physics. 169 00:08:52,679 --> 00:08:55,600 Speaker 3: If you can convince the funding agency that it's essential 170 00:08:55,840 --> 00:08:59,960 Speaker 3: for your research to make progress, then ya, I'll bet you. 171 00:09:00,240 --> 00:09:02,560 Speaker 3: And so today on the podcast, we'll be exploring one 172 00:09:02,600 --> 00:09:06,000 Speaker 3: of those potential directions to bring gravity and quantum mechanics 173 00:09:06,040 --> 00:09:09,600 Speaker 3: together to try to fit these two genius insights about 174 00:09:09,600 --> 00:09:13,640 Speaker 3: the way the universe works into one mega inside and 175 00:09:13,720 --> 00:09:21,240 Speaker 3: today in the podcast, we're asking the question what is 176 00:09:21,679 --> 00:09:26,760 Speaker 3: gravito electro magnetism? Boy? Is that a mouthful? I feel 177 00:09:26,760 --> 00:09:28,880 Speaker 3: like this must have been named by some German person. Yeah, 178 00:09:28,880 --> 00:09:30,160 Speaker 3: every time they come up with a name for something, 179 00:09:30,200 --> 00:09:31,920 Speaker 3: they just like stick a bunch of words together into 180 00:09:31,920 --> 00:09:33,400 Speaker 3: one super long word instead of. 181 00:09:33,320 --> 00:09:34,600 Speaker 4: Coming up with a new word. 182 00:09:34,800 --> 00:09:37,520 Speaker 1: It's use the words you already have, but stick them 183 00:09:37,520 --> 00:09:38,040 Speaker 1: all together. 184 00:09:40,120 --> 00:09:42,000 Speaker 3: Imagine if you came up with new ice cream flavors 185 00:09:42,040 --> 00:09:45,319 Speaker 3: that way, cookies and cream all one word. 186 00:09:45,480 --> 00:09:47,680 Speaker 4: Wait it isn't already. 187 00:09:48,240 --> 00:09:51,000 Speaker 3: No, No, I think that's exactly how they figured it out. 188 00:09:51,280 --> 00:09:54,480 Speaker 1: Like, I think it's interesting that I don't think I've 189 00:09:54,480 --> 00:09:57,000 Speaker 1: ever seen a question before of the audience where people 190 00:09:57,000 --> 00:09:59,280 Speaker 1: are just like, I can't even comprehend the name of this. 191 00:10:00,760 --> 00:10:02,920 Speaker 3: That's right, And so this was maybe a little bit 192 00:10:03,040 --> 00:10:05,840 Speaker 3: unfair to drop this on the listeners, But what the heck. 193 00:10:05,880 --> 00:10:08,160 Speaker 3: I think it's fun to ask the guys questions about 194 00:10:08,160 --> 00:10:10,800 Speaker 3: things you never heard about. So thanks very much to 195 00:10:10,800 --> 00:10:13,960 Speaker 3: everybody who volunteers for this audience participation segment of the 196 00:10:14,040 --> 00:10:17,079 Speaker 3: podcast and is caught aware by by very technical physics 197 00:10:17,160 --> 00:10:20,800 Speaker 3: questions without an opportunity to prepare We really appreciate you 198 00:10:20,840 --> 00:10:22,760 Speaker 3: being gained for this. If you would like to play 199 00:10:22,800 --> 00:10:25,480 Speaker 3: for future episodes of the podcast, please write to me 200 00:10:25,480 --> 00:10:29,559 Speaker 3: two questions at Danielanthorge dot com. So before you hear 201 00:10:29,600 --> 00:10:31,560 Speaker 3: these answers, think about it for a minute. What do 202 00:10:31,640 --> 00:10:36,960 Speaker 3: you think gravito electromagnetism could be. Here's what some listeners 203 00:10:37,000 --> 00:10:38,400 Speaker 3: had to say as. 204 00:10:38,640 --> 00:10:46,560 Speaker 2: The electrochage put off by strong gravity. Maybe I don't 205 00:10:46,600 --> 00:10:52,160 Speaker 2: know how you combine gravity and electromagnetism, but it sounds 206 00:10:52,280 --> 00:10:55,880 Speaker 2: like some kind of combo of the two. So maybe 207 00:10:55,960 --> 00:11:01,040 Speaker 2: it's the way in which electromagnetic fields are affected by gravity. 208 00:11:03,040 --> 00:11:10,240 Speaker 3: Or vice versa. I'm going to guess that gravito electromagnetism is. 209 00:11:10,600 --> 00:11:18,040 Speaker 1: The impact that gravity has on the electromagnetic force. I 210 00:11:18,080 --> 00:11:24,200 Speaker 1: wonder what insane clown posse has to say about gravito electromagnetism, 211 00:11:24,320 --> 00:11:25,640 Speaker 1: and if they know how it works? 212 00:11:25,880 --> 00:11:27,120 Speaker 4: Does that call back too old? 213 00:11:27,160 --> 00:11:27,439 Speaker 1: Now? 214 00:11:27,679 --> 00:11:28,319 Speaker 4: Am I old? 215 00:11:30,800 --> 00:11:34,240 Speaker 3: I'm not going to comment on it. I will say 216 00:11:34,240 --> 00:11:36,960 Speaker 3: that I am approaching fifty and so I've embraced being 217 00:11:37,000 --> 00:11:40,240 Speaker 3: fifty by calling myself fifty before I even got there. 218 00:11:40,920 --> 00:11:43,240 Speaker 3: And my kids think it's weird that I round myself 219 00:11:43,240 --> 00:11:45,280 Speaker 3: with to fifty, but I love it. 220 00:11:45,440 --> 00:11:46,200 Speaker 4: I do that too. 221 00:11:46,280 --> 00:11:49,120 Speaker 1: I round up so I'm not so shocked when it happens. 222 00:11:49,520 --> 00:11:52,240 Speaker 3: Exactly. That's what I was thinking. And then my daughter 223 00:11:52,280 --> 00:11:54,280 Speaker 3: asked me. She said, well, does that mean when you 224 00:11:54,320 --> 00:11:56,720 Speaker 3: turn fifty one you're gonna round yourself up to one hundred? 225 00:11:57,400 --> 00:11:57,760 Speaker 4: Why not? 226 00:11:58,000 --> 00:12:00,000 Speaker 3: Yeah, I thought, you know, for the sake of consistence, 227 00:12:00,240 --> 00:12:00,920 Speaker 3: I guess I have to. 228 00:12:01,880 --> 00:12:03,840 Speaker 1: I mean, you know, then you could be the oldest 229 00:12:03,840 --> 00:12:06,720 Speaker 1: person on earth, even before you start getting a pension. 230 00:12:07,800 --> 00:12:10,000 Speaker 3: That's true. I'm just hoping to get some of those 231 00:12:10,000 --> 00:12:15,319 Speaker 3: compliments like wow, Daniel, you look good for it. All right, 232 00:12:15,360 --> 00:12:18,439 Speaker 3: But back to the topic of quantum mechanics and gravity. 233 00:12:18,640 --> 00:12:21,640 Speaker 3: We see people are struggling to understand what this word means. 234 00:12:21,679 --> 00:12:23,760 Speaker 3: But there is a sense there that it's about some 235 00:12:24,000 --> 00:12:29,400 Speaker 3: relationship between gravity and electromagnetism. Maybe gravity is caused by electromagnetism, 236 00:12:29,520 --> 00:12:32,680 Speaker 3: or maybe you get electric charges from gravity. There's some 237 00:12:32,720 --> 00:12:33,800 Speaker 3: fun ideas in there. 238 00:12:33,960 --> 00:12:36,640 Speaker 4: It does sound like a little scammy. 239 00:12:37,080 --> 00:12:40,280 Speaker 1: It sounds like something where someone's trying to sell something 240 00:12:40,320 --> 00:12:43,800 Speaker 1: to me, because it's just so many technical sounding words 241 00:12:43,880 --> 00:12:48,160 Speaker 1: all smashed together. It's like, yeah, I kind of want 242 00:12:48,200 --> 00:12:51,199 Speaker 1: to know what it is. The only thing I can 243 00:12:51,200 --> 00:12:53,480 Speaker 1: think of like these listeners is just that it's like 244 00:12:53,600 --> 00:12:56,560 Speaker 1: kind of trying to smoosh the concepts of gravity and 245 00:12:56,600 --> 00:12:59,480 Speaker 1: electromagnetism together, but I kind of want to know more 246 00:12:59,520 --> 00:13:03,400 Speaker 1: specifically what that is and how that works. 247 00:13:03,640 --> 00:13:05,559 Speaker 3: Yeah, and so delay the groundwork. I think we need 248 00:13:05,600 --> 00:13:07,560 Speaker 3: to spell out a little bit of detail about like 249 00:13:08,200 --> 00:13:11,560 Speaker 3: why this problem is hard. Why is it difficult to 250 00:13:11,760 --> 00:13:16,840 Speaker 3: bring gravity and electromagnetism, or gravity and quantum mechanical theories 251 00:13:16,880 --> 00:13:20,840 Speaker 3: of forces together in general, And so we should probably 252 00:13:20,840 --> 00:13:23,600 Speaker 3: start with those quantum mechanical theories. And you know, we 253 00:13:23,640 --> 00:13:27,679 Speaker 3: talked about electromagnetism because it's one of the fundamental forces 254 00:13:27,679 --> 00:13:29,960 Speaker 3: that we know about in the universe. And all of 255 00:13:29,960 --> 00:13:33,640 Speaker 3: these fundamental forces are quantum mechanical, meaning that we have 256 00:13:33,679 --> 00:13:36,880 Speaker 3: a theory of quantum mechanics that describes particles and how 257 00:13:36,880 --> 00:13:39,640 Speaker 3: they move through space or how they exist and how 258 00:13:39,640 --> 00:13:43,680 Speaker 3: they have probabilities to exist. And those quantum mechanical theories, 259 00:13:43,720 --> 00:13:47,840 Speaker 3: those Shroninger equations and the lagrongins and the Hamiltonians, all 260 00:13:47,880 --> 00:13:52,280 Speaker 3: those mathematical structures are quantum mechanical and they describe the forces. 261 00:13:52,640 --> 00:13:55,760 Speaker 3: So we have electromagnetism, we have the weak force, and 262 00:13:55,800 --> 00:13:58,680 Speaker 3: we have the strong force. All these things can be 263 00:13:58,720 --> 00:14:01,120 Speaker 3: described using a quant maicaanical theory. It means we know 264 00:14:01,160 --> 00:14:04,680 Speaker 3: how to calculate what happens when one particle pushes or 265 00:14:04,720 --> 00:14:08,720 Speaker 3: pulls on another particle using one of these forces. Like 266 00:14:08,760 --> 00:14:11,320 Speaker 3: when two electrons are coming near each other, they repel 267 00:14:11,360 --> 00:14:13,880 Speaker 3: each other, and they use these forces to do so. 268 00:14:13,920 --> 00:14:17,719 Speaker 3: They use electromagnetism, And you can think about that quantum mechanically, 269 00:14:17,760 --> 00:14:22,120 Speaker 3: either as one electron has a big electromagnetic field and 270 00:14:22,160 --> 00:14:24,800 Speaker 3: that's pushing on the other electron, or if you prefer 271 00:14:24,840 --> 00:14:27,680 Speaker 3: the particle picture, you can imagine that the two electrons 272 00:14:27,720 --> 00:14:31,320 Speaker 3: are exchanging photons. They're tossing photons back and forth, and 273 00:14:31,360 --> 00:14:33,720 Speaker 3: that's how they're pushing on each other. But either way, 274 00:14:33,760 --> 00:14:36,600 Speaker 3: we have a nice quantum mechanical picture from the ground up, 275 00:14:36,640 --> 00:14:40,840 Speaker 3: from the littlest bits of these three fundamental forces electromagnetism, 276 00:14:41,080 --> 00:14:42,880 Speaker 3: the weak force, and the strong force. 277 00:14:43,320 --> 00:14:47,880 Speaker 1: So is gravity even weaker than the weak force? 278 00:14:48,880 --> 00:14:52,480 Speaker 3: Gravity is like ten to the thirty times weaker than 279 00:14:52,520 --> 00:14:56,400 Speaker 3: the weak force. It's almost unimaginably weak. It's so much 280 00:14:56,480 --> 00:14:59,120 Speaker 3: weaker than the other forces that it's a big puzzle 281 00:14:59,160 --> 00:15:02,080 Speaker 3: in physics. Like in physics we look for patterns and clues. 282 00:15:02,600 --> 00:15:05,280 Speaker 3: We expect things that are similar in nature to all 283 00:15:05,320 --> 00:15:09,040 Speaker 3: operate in under similar principles and have similar numbers. So 284 00:15:09,200 --> 00:15:11,400 Speaker 3: if you want a lump gravity in as one of 285 00:15:11,440 --> 00:15:14,280 Speaker 3: the forces, then you got to answer the question why 286 00:15:14,400 --> 00:15:17,840 Speaker 3: is it so much weaker than the other forces? Not 287 00:15:17,920 --> 00:15:19,920 Speaker 3: by a factor of ten, not by a factor of 288 00:15:19,960 --> 00:15:23,320 Speaker 3: one hundred, not by a million, but ten with thirty 289 00:15:23,480 --> 00:15:25,600 Speaker 3: zeros behind it. That's a big deal. 290 00:15:25,920 --> 00:15:29,680 Speaker 1: And so like the difference between electromagnetism, the weak force, 291 00:15:29,680 --> 00:15:33,160 Speaker 1: and strong force like is not nearly as big as 292 00:15:33,320 --> 00:15:36,840 Speaker 1: the difference between all those three and gravity. 293 00:15:37,280 --> 00:15:40,160 Speaker 3: Yeah, exactly. The strong force is like ten times more 294 00:15:40,200 --> 00:15:43,640 Speaker 3: powerful than electromagnetism, which is like one hundred times more 295 00:15:43,680 --> 00:15:47,000 Speaker 3: powerful than the weak force, which is like a gajillion 296 00:15:47,120 --> 00:15:49,360 Speaker 3: billion of jillion times more valuation. 297 00:15:49,560 --> 00:15:52,800 Speaker 1: To hang on, that doesn't even sound like a number, Okay, 298 00:15:52,800 --> 00:15:55,720 Speaker 1: but I get it. So gravity is so incredibly weak 299 00:15:55,760 --> 00:15:58,520 Speaker 1: it doesn't even seem like it's in the same category 300 00:15:59,280 --> 00:16:02,400 Speaker 1: as these other things. It's like comparing like a blue 301 00:16:02,440 --> 00:16:03,600 Speaker 1: whale to an ant. 302 00:16:03,800 --> 00:16:07,000 Speaker 3: Yeah, that's exactly right now, fundamentally, that's not a problem. 303 00:16:07,080 --> 00:16:10,720 Speaker 3: Like it's possible that you could have for forces in 304 00:16:10,720 --> 00:16:13,040 Speaker 3: the universe and one of them is just much weaker. 305 00:16:13,360 --> 00:16:15,760 Speaker 3: There are ways that you can do that. It's not 306 00:16:15,800 --> 00:16:18,480 Speaker 3: an insurmountable issue. It's strange and it would make you 307 00:16:18,480 --> 00:16:21,920 Speaker 3: ask like why is that and to look for explanations, 308 00:16:22,400 --> 00:16:25,600 Speaker 3: but mathematically it doesn't prevent us from describing it. That's 309 00:16:25,720 --> 00:16:28,400 Speaker 3: not the challenge with gravity. If you sit down and 310 00:16:28,440 --> 00:16:31,800 Speaker 3: try to describe gravity using some kinds of maths similar 311 00:16:32,120 --> 00:16:34,640 Speaker 3: to the way we describe electromagnetism and the weak force 312 00:16:34,680 --> 00:16:37,400 Speaker 3: and strong force, to come up with like a quantum 313 00:16:37,440 --> 00:16:40,440 Speaker 3: theory of gravity that describes it as a force. Then 314 00:16:40,480 --> 00:16:43,160 Speaker 3: you start to build in gravitational fields and you can 315 00:16:43,160 --> 00:16:46,320 Speaker 3: think about the quantized ripples in those fields as particles. 316 00:16:46,600 --> 00:16:49,560 Speaker 3: In this case, it would be the graviton. So when 317 00:16:49,560 --> 00:16:52,400 Speaker 3: two planets come near each other and pull on each other, 318 00:16:52,760 --> 00:16:57,120 Speaker 3: the quantum picture of gravity would have them exchanging gravitons 319 00:16:57,560 --> 00:17:00,920 Speaker 3: the way two electrons are like exchange photon. So you 320 00:17:00,920 --> 00:17:03,960 Speaker 3: can start to go down that road mathematically and things 321 00:17:04,000 --> 00:17:06,760 Speaker 3: seem okay. You just like dial the force way way 322 00:17:06,800 --> 00:17:09,119 Speaker 3: down to make it super duper weak, but then you 323 00:17:09,240 --> 00:17:12,560 Speaker 3: run into a lot of mathematical problems actually making that 324 00:17:12,600 --> 00:17:13,320 Speaker 3: theory work. 325 00:17:13,560 --> 00:17:16,159 Speaker 1: How do you check your math in a situation like this, 326 00:17:16,440 --> 00:17:19,119 Speaker 1: Like what are the kinds of mathematical problems that you 327 00:17:19,200 --> 00:17:21,600 Speaker 1: run into? And how do you know that they're problems? 328 00:17:22,040 --> 00:17:24,760 Speaker 3: Yeah? Great question. The way that you know that your 329 00:17:24,760 --> 00:17:27,680 Speaker 3: theory is working or not working is that you try 330 00:17:27,720 --> 00:17:30,440 Speaker 3: to use it and you see if it gives reasonable results. 331 00:17:31,000 --> 00:17:32,560 Speaker 3: Like if you ask, I want to push these two 332 00:17:32,600 --> 00:17:36,480 Speaker 3: particles together, I want to calculate the probability of various outcomes. 333 00:17:36,480 --> 00:17:38,040 Speaker 3: I want to know the particles are going to bounce 334 00:17:38,040 --> 00:17:39,560 Speaker 3: off each other, or if they're going to scatter off 335 00:17:39,560 --> 00:17:41,680 Speaker 3: at this angle or at that angle. So you try 336 00:17:41,680 --> 00:17:45,160 Speaker 3: to calculate things. You try to make predictions in physics. 337 00:17:45,160 --> 00:17:48,200 Speaker 3: For your predictions to be reasonable, there's some limits. There's 338 00:17:48,200 --> 00:17:52,600 Speaker 3: some restrictions, like your predictions can't have probabilities greater than one. 339 00:17:52,920 --> 00:17:54,639 Speaker 3: If you ask, like is my electron going to go 340 00:17:54,720 --> 00:17:56,919 Speaker 3: left or right? And your theory says you have one 341 00:17:56,960 --> 00:17:59,240 Speaker 3: hundred and seventy five percent chance of its going left, 342 00:17:59,280 --> 00:18:02,359 Speaker 3: And you're like, hm, well that's that seems wrong. That 343 00:18:02,400 --> 00:18:03,200 Speaker 3: can't r right. 344 00:18:03,240 --> 00:18:05,760 Speaker 1: So when my gym teacher told me to give it 345 00:18:05,760 --> 00:18:08,640 Speaker 1: my one hundred and ten percent. Like, that's not right, 346 00:18:08,960 --> 00:18:10,440 Speaker 1: that's physically impossible. 347 00:18:11,640 --> 00:18:13,640 Speaker 4: That's right, my all. 348 00:18:14,480 --> 00:18:17,360 Speaker 3: Your gym teacher is violating the fundamental rules. 349 00:18:17,040 --> 00:18:18,680 Speaker 4: Of physicals call them up right now. 350 00:18:18,760 --> 00:18:21,160 Speaker 3: Or maybe your gym teacher is a quantum gravity theorist, 351 00:18:21,920 --> 00:18:24,520 Speaker 3: because that's exactly what happens when we try to make 352 00:18:24,600 --> 00:18:29,239 Speaker 3: a quantum gravity theory. Gravitons are really tricky because they 353 00:18:29,240 --> 00:18:33,120 Speaker 3: don't just transmit gravity. They have energy themselves, which means 354 00:18:33,160 --> 00:18:37,280 Speaker 3: they also couple to gravity. They feel gravity, they emit gravity. 355 00:18:37,760 --> 00:18:42,040 Speaker 3: So like when you emit a photon, photons don't feel electromagnetism, 356 00:18:42,280 --> 00:18:44,720 Speaker 3: they don't bounce off of other photons, they don't emit 357 00:18:44,800 --> 00:18:49,160 Speaker 3: other photons. Right, Photons don't feel electric charges because they 358 00:18:49,160 --> 00:18:52,080 Speaker 3: are neutral. They don't have a charge themselves, so they 359 00:18:52,119 --> 00:18:54,639 Speaker 3: will like fly right through an electric field. But a 360 00:18:54,680 --> 00:18:58,920 Speaker 3: graviton has energy, and gravity is felt by everything with energy, 361 00:18:59,119 --> 00:19:03,160 Speaker 3: So graviton feel gravity, which means they emit more gravitons, 362 00:19:03,359 --> 00:19:06,159 Speaker 3: and those gravitons emit more gravitons, and pretty soon you 363 00:19:06,200 --> 00:19:08,560 Speaker 3: have an infinite number of gravitons, and you start to 364 00:19:08,560 --> 00:19:10,639 Speaker 3: get nonsense answers out of your theory. 365 00:19:11,000 --> 00:19:14,119 Speaker 1: When you say a graviton, right, I'm thinking of a 366 00:19:14,200 --> 00:19:20,280 Speaker 1: particle sort of like a photon. But photons we've actually measured, right, 367 00:19:20,320 --> 00:19:23,240 Speaker 1: We've actually been able to sort of get physical evidence 368 00:19:23,280 --> 00:19:26,400 Speaker 1: of their existence. Like, do we have like physical evidence 369 00:19:26,480 --> 00:19:32,040 Speaker 1: of the existence of gravitons as like an existing thing 370 00:19:32,600 --> 00:19:34,800 Speaker 1: other than just knowing that gravity exists. 371 00:19:35,240 --> 00:19:38,359 Speaker 3: We do not have any evidence of gravitons. We have 372 00:19:38,440 --> 00:19:41,480 Speaker 3: a very successful theory of gravity. It's Einstein's theory of 373 00:19:41,520 --> 00:19:45,600 Speaker 3: general relativity that describes how space and time bend around 374 00:19:45,720 --> 00:19:48,680 Speaker 3: masses and that affects how things move, and that's very, 375 00:19:48,760 --> 00:19:51,680 Speaker 3: very precise, but that describes gravity as not a force. 376 00:19:51,720 --> 00:19:54,359 Speaker 3: It's like a bending in space and time. We're going 377 00:19:54,400 --> 00:19:56,600 Speaker 3: to switch over and try to think about gravity as 378 00:19:56,640 --> 00:19:59,879 Speaker 3: a force instead of bending in space and time. Then 379 00:20:00,080 --> 00:20:03,159 Speaker 3: you need these gravitons, and nobody's ever seen them. The 380 00:20:03,240 --> 00:20:06,320 Speaker 3: reason they're so hard to see is precisely because gravity 381 00:20:06,400 --> 00:20:09,720 Speaker 3: is so weak, Like electromagnetism is a pretty strong force. 382 00:20:10,000 --> 00:20:12,680 Speaker 3: Electrons are radiating photons all the time. It's not a 383 00:20:12,800 --> 00:20:15,679 Speaker 3: rare thing to happen in the universe. But gravitons are 384 00:20:15,720 --> 00:20:18,760 Speaker 3: more rare because gravity is so weak, and they're much 385 00:20:18,800 --> 00:20:22,040 Speaker 3: harder to see because gravity is so weak, so the 386 00:20:22,080 --> 00:20:25,760 Speaker 3: impact of like one graviton would be very very hard 387 00:20:25,800 --> 00:20:28,720 Speaker 3: to detect. So we don't know that gravitons are real, 388 00:20:29,119 --> 00:20:31,480 Speaker 3: but they are a necessary part of a theory of 389 00:20:31,560 --> 00:20:34,600 Speaker 3: quantum gravity that tries to make gravity look like a 390 00:20:34,760 --> 00:20:38,240 Speaker 3: force and fitted it into this quantum mechanical framework. So far, 391 00:20:38,280 --> 00:20:40,240 Speaker 3: and nobody's even been able to make the math work 392 00:20:40,560 --> 00:20:43,160 Speaker 3: to have like a consistent theory that we could even 393 00:20:43,200 --> 00:20:44,920 Speaker 3: go out and test in experiments. 394 00:20:45,080 --> 00:20:48,560 Speaker 1: So we can't make the math work. We can't even 395 00:20:48,560 --> 00:20:52,920 Speaker 1: find any evidence that gravitons exist. Things are looking pretty good, 396 00:20:53,080 --> 00:20:56,920 Speaker 1: pretty good so far. Maybe we should take a quick break. 397 00:20:57,160 --> 00:20:59,920 Speaker 1: I will look around see if I've got any gravitons 398 00:21:00,160 --> 00:21:03,240 Speaker 1: just kind of lying around, you never know, And then 399 00:21:03,280 --> 00:21:06,160 Speaker 1: when we get back, maybe we can take another crack 400 00:21:06,240 --> 00:21:09,920 Speaker 1: at this and see if there's any anything that actually 401 00:21:09,960 --> 00:21:14,080 Speaker 1: where the math you carry the ones and it all works. 402 00:21:13,840 --> 00:21:28,320 Speaker 4: Out all right. So bad news. 403 00:21:28,600 --> 00:21:32,720 Speaker 1: Daniel couldn't find any gravitons, not a single one. I'm 404 00:21:32,720 --> 00:21:36,600 Speaker 1: also out of milk, so things aren't looking so good 405 00:21:36,720 --> 00:21:39,520 Speaker 1: here do you have any good news for me in 406 00:21:39,600 --> 00:21:45,400 Speaker 1: our effort to smoosh together quantum mechanics and general relativity. 407 00:21:45,760 --> 00:21:47,760 Speaker 3: I didn't figure it out in the last couple of minutes, 408 00:21:47,800 --> 00:21:49,880 Speaker 3: but you know, a lot of clever people have been 409 00:21:49,920 --> 00:21:53,760 Speaker 3: thinking about this and trying to find some connections between 410 00:21:53,760 --> 00:21:58,359 Speaker 3: gravity and electromagnetism, or between electromagnetism and gravity, sort of 411 00:21:58,400 --> 00:22:01,720 Speaker 3: going both directions, trying to make gravity look more like 412 00:22:01,920 --> 00:22:05,360 Speaker 3: electromagnetism and the theoretical side, or giving up on that 413 00:22:05,440 --> 00:22:08,880 Speaker 3: and trying to make electromagnetism look more like gravity. So 414 00:22:08,920 --> 00:22:11,480 Speaker 3: we don't have any experimental results to guide us, but 415 00:22:11,520 --> 00:22:13,880 Speaker 3: we can still think deeply about the structure of these 416 00:22:13,920 --> 00:22:17,960 Speaker 3: theories and try to make some theoretical progress in our minds. 417 00:22:18,200 --> 00:22:19,399 Speaker 3: Magic mushrooms or no. 418 00:22:20,840 --> 00:22:23,879 Speaker 1: All right, so we're in the mindscape. What are we 419 00:22:23,960 --> 00:22:27,440 Speaker 1: doing in order to solve the hurdle of the math 420 00:22:27,680 --> 00:22:29,760 Speaker 1: not mathing in this idea, because it sounds like we 421 00:22:29,800 --> 00:22:32,800 Speaker 1: were sort of trying to think of planets as like 422 00:22:32,880 --> 00:22:38,760 Speaker 1: scaled up particles and gravity as like a force between them, 423 00:22:39,119 --> 00:22:43,159 Speaker 1: as if they're giant particles, and that didn't really work. Like, 424 00:22:43,840 --> 00:22:46,359 Speaker 1: is there another approach that you could use or is 425 00:22:46,400 --> 00:22:48,840 Speaker 1: there a way to like fine tune that approach such 426 00:22:48,920 --> 00:22:50,399 Speaker 1: that it actually does work. 427 00:22:50,800 --> 00:22:53,440 Speaker 3: Yeah, So the short answer is there isn't a great approach, 428 00:22:53,600 --> 00:22:56,000 Speaker 3: but that doesn't mean we can't make progress. And I 429 00:22:56,000 --> 00:22:58,760 Speaker 3: think people should understand that. In theoretical physics, it's not 430 00:22:58,800 --> 00:23:00,480 Speaker 3: like you sit down one day and come up with 431 00:23:00,480 --> 00:23:05,520 Speaker 3: the whole theory movies. You're entering like a mathematical jungle. 432 00:23:05,560 --> 00:23:08,080 Speaker 3: You're not sure if there is a path through, and 433 00:23:08,119 --> 00:23:11,240 Speaker 3: it takes exploration. Exploration is not just something we do 434 00:23:11,359 --> 00:23:15,159 Speaker 3: in experimental physics or in experimental biology. We're like walking 435 00:23:15,160 --> 00:23:17,680 Speaker 3: through a literal jungle looking for new kinds of frogs. 436 00:23:18,160 --> 00:23:20,840 Speaker 3: In theoretical physics, you can also explore. You can just 437 00:23:20,880 --> 00:23:22,879 Speaker 3: like try stuff and say, well, I'm going to go 438 00:23:22,920 --> 00:23:25,480 Speaker 3: in this direction and see if it works out, kind 439 00:23:25,480 --> 00:23:27,280 Speaker 3: of like when you're trying a proof in tenth grade 440 00:23:27,280 --> 00:23:29,159 Speaker 3: geometry and you're like, well, I'm not sure this is 441 00:23:29,160 --> 00:23:30,399 Speaker 3: gonna get me where I need to go, but I'm 442 00:23:30,400 --> 00:23:34,280 Speaker 3: gonna play around with these angles. And so in theoretical physics, 443 00:23:34,280 --> 00:23:37,359 Speaker 3: people are trying something that has a long tradition dating 444 00:23:37,400 --> 00:23:40,880 Speaker 3: all the way back to like Maxwell James Clerk, Maxwell 445 00:23:40,880 --> 00:23:44,000 Speaker 3: in the eighteen hundreds was looking at theories of electricity 446 00:23:44,040 --> 00:23:47,439 Speaker 3: and theories of magnetism, and he tried something cool. He said, well, 447 00:23:47,480 --> 00:23:50,639 Speaker 3: let me write down the equations for electricity and write 448 00:23:50,680 --> 00:23:53,400 Speaker 3: down the equations for magnetism and try to smooth them 449 00:23:53,400 --> 00:23:55,880 Speaker 3: together and make them look as much like each other 450 00:23:55,960 --> 00:23:58,920 Speaker 3: as possible. And when he did that, he realized, oh, 451 00:23:58,920 --> 00:24:02,439 Speaker 3: my gosh, these basically have the same equations. And not 452 00:24:02,480 --> 00:24:04,840 Speaker 3: only that, but you can click the equations together because 453 00:24:04,880 --> 00:24:08,240 Speaker 3: sometimes electric field cause magnetic field and vice versa to 454 00:24:08,320 --> 00:24:11,320 Speaker 3: make one bigger picture. So we had this great insight, 455 00:24:11,359 --> 00:24:14,480 Speaker 3: which is where we got the theory of electromagnetism. So 456 00:24:14,520 --> 00:24:16,480 Speaker 3: now people are trying to do something similar. They're saying, 457 00:24:16,920 --> 00:24:20,520 Speaker 3: let's look at the equations for electromagnetism and the equations 458 00:24:20,520 --> 00:24:23,320 Speaker 3: for gravity and see if we can find relationships. Are 459 00:24:23,320 --> 00:24:25,040 Speaker 3: they like a mirror image of each other? Can we 460 00:24:25,119 --> 00:24:28,320 Speaker 3: somehow find patterns there and then use that to guide 461 00:24:28,440 --> 00:24:32,119 Speaker 3: us through this intellectual jungle to a theory that combines 462 00:24:32,160 --> 00:24:35,199 Speaker 3: gravity and electromagnetism into one big theory. 463 00:24:35,440 --> 00:24:39,159 Speaker 1: So for someone just theoretically who does not have a 464 00:24:39,280 --> 00:24:44,120 Speaker 1: grasp of what theoretical math would look like, and when 465 00:24:44,119 --> 00:24:46,000 Speaker 1: you say equations, like what that is? 466 00:24:46,040 --> 00:24:47,440 Speaker 4: Like are we. 467 00:24:47,400 --> 00:24:50,159 Speaker 1: Talking about like you have five equations that you have 468 00:24:50,200 --> 00:24:54,520 Speaker 1: to memorize to understand gravity? Like are there hundreds of equations? 469 00:24:55,400 --> 00:25:00,280 Speaker 1: And when you're trying to like smash together equations, you know, 470 00:25:00,400 --> 00:25:02,720 Speaker 1: is it sort of like a brilliant mind where you 471 00:25:02,800 --> 00:25:06,440 Speaker 1: just see floating numbers kind of going together and doing 472 00:25:06,480 --> 00:25:10,800 Speaker 1: things like what in terms that someone like me who 473 00:25:11,240 --> 00:25:13,399 Speaker 1: math is trying to calculate a tip? 474 00:25:14,359 --> 00:25:15,280 Speaker 4: How does that work? 475 00:25:15,680 --> 00:25:17,680 Speaker 3: Yeah, that's a great question, and we could start off 476 00:25:17,720 --> 00:25:21,639 Speaker 3: pretty simply. You know, people are probably familiar with Newton's 477 00:25:21,760 --> 00:25:24,960 Speaker 3: law of gravity. That just says that the force between 478 00:25:25,040 --> 00:25:29,080 Speaker 3: two objects is proportional to the two masses divided by 479 00:25:29,080 --> 00:25:31,760 Speaker 3: the distance between them squared, and then you multiply that 480 00:25:31,760 --> 00:25:35,679 Speaker 3: whole thing by a constant big G Newton's constant. So 481 00:25:35,880 --> 00:25:39,399 Speaker 3: Newton's equation for the force between two objects is like 482 00:25:39,880 --> 00:25:43,400 Speaker 3: gmm over R squared. All right, So that's Newton's theory 483 00:25:43,440 --> 00:25:46,480 Speaker 3: of gravity. Then we can look over at electromagnetism. We 484 00:25:46,520 --> 00:25:49,040 Speaker 3: can say, what's the equation for the force between two 485 00:25:49,160 --> 00:25:52,800 Speaker 3: particles that have charge? Like remember our question was like 486 00:25:52,840 --> 00:25:54,959 Speaker 3: what happens when two electrons come near each other. Can 487 00:25:54,960 --> 00:25:58,320 Speaker 3: we calculate that well, Kulham's law tells us that the 488 00:25:58,320 --> 00:26:02,040 Speaker 3: force between two parts particles goes like the charge of 489 00:26:02,080 --> 00:26:05,520 Speaker 3: the two particles divided by the distance squared between them, 490 00:26:05,880 --> 00:26:09,239 Speaker 3: all multiplied by a constant in this case K. So 491 00:26:09,280 --> 00:26:11,720 Speaker 3: you look at these two equations, you notice instantly, like HM, 492 00:26:11,880 --> 00:26:14,920 Speaker 3: these have kind of similar structures. On the top of 493 00:26:14,960 --> 00:26:18,280 Speaker 3: the equation is the charge of the two objects. Where 494 00:26:18,400 --> 00:26:21,840 Speaker 3: gravity the charge would be the mass, and for electromagnetism 495 00:26:21,920 --> 00:26:24,679 Speaker 3: the charge is obviously the electric charge. And both of 496 00:26:24,720 --> 00:26:27,880 Speaker 3: them get weaker as the distance grows by the same 497 00:26:27,960 --> 00:26:31,960 Speaker 3: power you get twice as far apart. Gravity and electromagnetism 498 00:26:32,080 --> 00:26:35,280 Speaker 3: both get four times weaker. You go ten times further away, 499 00:26:35,600 --> 00:26:38,959 Speaker 3: the force of gravity and electromagnetism both go down by 500 00:26:39,000 --> 00:26:41,760 Speaker 3: a power of one hundred. So they have very similar 501 00:26:41,800 --> 00:26:44,000 Speaker 3: structures there already. That's encouraging. 502 00:26:44,520 --> 00:26:47,680 Speaker 1: But if it was just as simple as finding sort 503 00:26:47,720 --> 00:26:50,679 Speaker 1: of some of these equations that seem to look kind 504 00:26:50,680 --> 00:26:53,679 Speaker 1: of similar and match them together, like it seems like 505 00:26:53,720 --> 00:26:57,520 Speaker 1: we would have already figured this out. So what is 506 00:26:57,600 --> 00:27:00,280 Speaker 1: the scale of the complexity, Like, why have it we've 507 00:27:00,280 --> 00:27:02,520 Speaker 1: been able to find just like a bunch of these 508 00:27:02,560 --> 00:27:04,959 Speaker 1: equations that kind of look similar and seem to have 509 00:27:05,040 --> 00:27:08,040 Speaker 1: the same general structure and have them work together. 510 00:27:08,320 --> 00:27:10,119 Speaker 3: Yeah. Well, one issue, of course, is that we know 511 00:27:10,200 --> 00:27:12,679 Speaker 3: that Newton's theory of gravity is not the right theory. 512 00:27:13,000 --> 00:27:13,480 Speaker 4: Whoops. 513 00:27:15,240 --> 00:27:17,119 Speaker 3: When Newton was a very clever man, and he has 514 00:27:17,160 --> 00:27:20,359 Speaker 3: a very nice theory which mostly works but not. 515 00:27:20,280 --> 00:27:22,440 Speaker 4: Quite irresponsible with apples too. 516 00:27:24,920 --> 00:27:28,040 Speaker 3: Einstein's theory of gravity is not just a reimagining. It's 517 00:27:28,040 --> 00:27:30,760 Speaker 3: not just saying, look, the story is wrong. It's not 518 00:27:30,840 --> 00:27:33,359 Speaker 3: a force between objects, it's a bending of space and time. 519 00:27:33,720 --> 00:27:38,320 Speaker 3: It also gives different predictions, like, for example, Newton says 520 00:27:38,400 --> 00:27:40,600 Speaker 3: that the force just depends on the mass. It doesn't 521 00:27:40,640 --> 00:27:44,080 Speaker 3: depend on whether the object is spinning or not. So 522 00:27:44,119 --> 00:27:46,639 Speaker 3: according to Newton, if you're in orbit around the Earth, 523 00:27:47,000 --> 00:27:49,439 Speaker 3: whether the Earth is spinning or if it stopped spinning 524 00:27:49,520 --> 00:27:52,360 Speaker 3: or spinning the other way makes no difference for gravity. 525 00:27:52,840 --> 00:27:56,280 Speaker 3: Einstein says, Nope, that's not true. If the Earth is spinning, 526 00:27:56,320 --> 00:27:59,000 Speaker 3: that has more energy, and since gravity is linked to 527 00:27:59,240 --> 00:28:02,760 Speaker 3: energy of all kinds, not just mass, that changes the 528 00:28:02,800 --> 00:28:07,359 Speaker 3: gravitational force on the object in a complicated way. So 529 00:28:07,480 --> 00:28:10,320 Speaker 3: Einstein's equations are much more complicated than Newton's. He doesn't 530 00:28:10,359 --> 00:28:13,119 Speaker 3: just have like one simple force equation. He's got a 531 00:28:13,200 --> 00:28:16,560 Speaker 3: really complicated tensor equation, where a tensor it's just like 532 00:28:16,600 --> 00:28:19,760 Speaker 3: a matrix. It's like an array in computer programming, you know, 533 00:28:19,760 --> 00:28:21,640 Speaker 3: a way to keep track of a bunch of numbers 534 00:28:21,680 --> 00:28:24,800 Speaker 3: all at once. So he has more complicated equations. And 535 00:28:24,880 --> 00:28:27,520 Speaker 3: so you can't just say, look, Newton's law and kulums 536 00:28:27,560 --> 00:28:30,399 Speaker 3: are similar. You got to dig deep into Einstein's rules 537 00:28:30,400 --> 00:28:30,960 Speaker 3: for gravity. 538 00:28:31,080 --> 00:28:34,200 Speaker 1: So how do we know Einstein is right and Newton 539 00:28:34,280 --> 00:28:37,520 Speaker 1: is wrong. It can't just be that Einstein's got cooler 540 00:28:37,560 --> 00:28:40,040 Speaker 1: hair or more complex equations. 541 00:28:40,480 --> 00:28:44,520 Speaker 3: Well, Einstein and Newton make different predictions, and famously Einstein's 542 00:28:44,520 --> 00:28:48,400 Speaker 3: predictions were right. Einstein predicted stuff about how light bends 543 00:28:48,440 --> 00:28:51,320 Speaker 3: around the Sun during an eclipse, and he predicted stuff 544 00:28:51,320 --> 00:28:54,280 Speaker 3: about how mercury orbits the Sun and the angle of 545 00:28:54,320 --> 00:28:57,640 Speaker 3: the eclipse of mercury, how that twists as mercury is 546 00:28:57,720 --> 00:29:00,920 Speaker 3: orbiting the Sun. All these little difference between Newton and 547 00:29:00,920 --> 00:29:03,640 Speaker 3: Einstein add up and a few special cases, so we 548 00:29:03,760 --> 00:29:06,880 Speaker 3: know that Einstein's theory was right. So then people took 549 00:29:06,920 --> 00:29:09,200 Speaker 3: this on. They're like Okay, well, can I take Einstein's 550 00:29:09,200 --> 00:29:13,440 Speaker 3: equations and try to make them look like electromagnetism. Like 551 00:29:13,520 --> 00:29:15,640 Speaker 3: we were able to take Newton's law and make it 552 00:29:15,640 --> 00:29:19,360 Speaker 3: look like Kulam's law. Can we take Einstein's gravity and 553 00:29:19,400 --> 00:29:23,480 Speaker 3: make it look like electromagnetism? And people have actually succeeded 554 00:29:23,520 --> 00:29:28,200 Speaker 3: in doing this. There are these Gravita electromagnetic equations when 555 00:29:28,240 --> 00:29:30,200 Speaker 3: if you write them down, you get equations that look 556 00:29:30,360 --> 00:29:35,640 Speaker 3: very similar to Maxwell's equations for electromagnetism. Maxwell has four equations, 557 00:29:35,680 --> 00:29:37,840 Speaker 3: and I won't get into the math with you. You know, 558 00:29:37,880 --> 00:29:40,640 Speaker 3: there's a there's like a divergence and a curl for 559 00:29:40,680 --> 00:29:46,240 Speaker 3: electricity and magnetism and indie gravita electromagnetic equations. There are 560 00:29:46,280 --> 00:29:50,120 Speaker 3: also four equations and have a very similar structure to 561 00:29:50,200 --> 00:29:52,840 Speaker 3: Maxwell's equations. You should look them up and write them 562 00:29:52,880 --> 00:29:55,920 Speaker 3: side by side. They look very very similar. It's eerie, 563 00:29:55,920 --> 00:29:58,640 Speaker 3: it's spooky. It's like the universe is saying, oh, look, 564 00:29:58,720 --> 00:30:01,560 Speaker 3: you found the pattern. It's over here in the gravity 565 00:30:01,600 --> 00:30:03,600 Speaker 3: world and in the electromagnetic world. 566 00:30:03,840 --> 00:30:07,640 Speaker 1: This does feel like a conspiracy theorist sort of aligning 567 00:30:07,840 --> 00:30:10,840 Speaker 1: charts and with a corkboard and yarn and trying to 568 00:30:10,840 --> 00:30:14,680 Speaker 1: make these connections. But yeah, I mean, I'm looking at 569 00:30:14,720 --> 00:30:16,920 Speaker 1: this and you know, I don't know a look of 570 00:30:17,080 --> 00:30:20,440 Speaker 1: complex math, but it yes, they look very similar. 571 00:30:20,960 --> 00:30:21,720 Speaker 4: But if we've. 572 00:30:21,560 --> 00:30:24,760 Speaker 1: Found this, right, it doesn't mean that we've figured out 573 00:30:24,760 --> 00:30:28,840 Speaker 1: how they interlock. Like we found some similarities, some equations 574 00:30:28,880 --> 00:30:31,840 Speaker 1: that seem to match, but the bigger picture has not 575 00:30:32,080 --> 00:30:33,520 Speaker 1: yet become clear. 576 00:30:33,760 --> 00:30:35,479 Speaker 3: Yeah, that's right, and I hear you setting me up 577 00:30:35,480 --> 00:30:37,400 Speaker 3: to deliver the bad news of why this is going 578 00:30:37,480 --> 00:30:40,480 Speaker 3: to work. But first there's a little bit more good, okay, 579 00:30:40,520 --> 00:30:42,840 Speaker 3: which I think is a fun insight into how this works. 580 00:30:43,440 --> 00:30:46,560 Speaker 3: The thing about Einstein's equations for gravity, as we were 581 00:30:46,560 --> 00:30:48,680 Speaker 3: saying before, is that it gives you more than just 582 00:30:48,800 --> 00:30:52,960 Speaker 3: like a straightforce between two objects. Spinning objects can create 583 00:30:53,040 --> 00:30:56,720 Speaker 3: like torque and drag in space time itself, which gives 584 00:30:56,720 --> 00:30:59,520 Speaker 3: all sorts of weird forces, like if you are orbiting 585 00:30:59,560 --> 00:31:02,200 Speaker 3: the Earth and the Earth is spinning, then there's some 586 00:31:02,360 --> 00:31:05,480 Speaker 3: frame dragging effects there. Check out our whole episode about 587 00:31:05,480 --> 00:31:08,200 Speaker 3: that if you want more details. But effectively, it gives 588 00:31:08,200 --> 00:31:10,720 Speaker 3: like a twist on things that are orbiting the Earth. 589 00:31:11,080 --> 00:31:14,240 Speaker 3: So according to Einstein's gravity, it's not just a force 590 00:31:14,280 --> 00:31:17,120 Speaker 3: between two objects. There are more subtle effects there. And 591 00:31:17,160 --> 00:31:21,640 Speaker 3: the really cool thing is that in the gravito electromagnetic equations, 592 00:31:21,880 --> 00:31:24,040 Speaker 3: the ones where you take Einstein's gravity and try to 593 00:31:24,080 --> 00:31:28,360 Speaker 3: convert them to look like electromagnetism, you can see this emerge. 594 00:31:28,960 --> 00:31:31,760 Speaker 3: And in those equations you have what they call a 595 00:31:31,920 --> 00:31:34,760 Speaker 3: gravito electric field, which is sort of like the straight 596 00:31:34,840 --> 00:31:40,520 Speaker 3: up Newtonian version, plus this gravito magnetic field. So basically, 597 00:31:40,560 --> 00:31:43,720 Speaker 3: to explain all of Einstein's gravity you break it up 598 00:31:43,760 --> 00:31:46,680 Speaker 3: into two pieces, this analogy to the electric field and 599 00:31:46,760 --> 00:31:49,920 Speaker 3: this analogy to the magnetic field. And it goes even 600 00:31:49,920 --> 00:31:52,280 Speaker 3: deeper than that, because it's not just notation. It's not 601 00:31:52,400 --> 00:31:54,560 Speaker 3: just like, hey, let's write this down in a cute 602 00:31:54,560 --> 00:31:56,840 Speaker 3: way that looks sort of similar. There really is a 603 00:31:56,880 --> 00:32:01,320 Speaker 3: conceptual connection there because an electromagnetic the way you get 604 00:32:01,320 --> 00:32:04,520 Speaker 3: magnetic fields is you take electric fields and you wiggle 605 00:32:04,560 --> 00:32:07,760 Speaker 3: them like currents of electrons give you magnetic fields. So 606 00:32:07,800 --> 00:32:11,840 Speaker 3: it's like velocity dependent, right. Well, the cool thing about 607 00:32:11,840 --> 00:32:16,160 Speaker 3: the gravitomagnetic field, this other component of these equations you 608 00:32:16,200 --> 00:32:18,720 Speaker 3: have to add on to be able to describe Einstein's 609 00:32:18,760 --> 00:32:22,920 Speaker 3: gravity with equations that look like electromagnetism is that they 610 00:32:22,920 --> 00:32:27,840 Speaker 3: create velocity dependent acceleration in just the same way. For example, 611 00:32:27,880 --> 00:32:30,920 Speaker 3: those spinning masses. When the Earth is spinning, that's an 612 00:32:31,000 --> 00:32:34,520 Speaker 3: acceleration because any sort of rotation is an acceleration, and 613 00:32:34,560 --> 00:32:38,040 Speaker 3: that gives an acceleration. On satellites, it gives a twist, 614 00:32:38,080 --> 00:32:41,560 Speaker 3: it gives a pull. So when you force gravity into 615 00:32:41,600 --> 00:32:45,320 Speaker 3: this structure that looks like electromagnetism, you learn some things 616 00:32:45,360 --> 00:32:48,320 Speaker 3: about gravity. It like sorts it in your mind in 617 00:32:48,360 --> 00:32:50,320 Speaker 3: a way that actually gives you a little bit of insight. 618 00:32:50,680 --> 00:32:53,280 Speaker 3: And that's a good sign. When you're bushwhacking your way 619 00:32:53,320 --> 00:32:56,400 Speaker 3: through the theoretical jungle trying to make connections between things. 620 00:32:56,600 --> 00:32:59,280 Speaker 3: You don't have to force things into categories. When they 621 00:32:59,280 --> 00:33:02,400 Speaker 3: sort of naturally fall into those categories and reveals something 622 00:33:02,480 --> 00:33:05,160 Speaker 3: deep about the nature of that force or the nature 623 00:33:05,160 --> 00:33:07,560 Speaker 3: of the phenomenon, it's a sign that you might be 624 00:33:07,680 --> 00:33:10,720 Speaker 3: on the right track. So that's the good news that 625 00:33:10,760 --> 00:33:14,680 Speaker 3: there really is something satisfying about making gravity look like 626 00:33:14,720 --> 00:33:17,960 Speaker 3: the equations of electromagnetism. It's not just like hacking it 627 00:33:18,040 --> 00:33:19,880 Speaker 3: up into bits and shoving it in boxes. 628 00:33:20,000 --> 00:33:23,480 Speaker 1: It's not just using the same colored gelpins to write 629 00:33:23,480 --> 00:33:24,360 Speaker 1: the equation. 630 00:33:25,480 --> 00:33:25,960 Speaker 3: Exactly. 631 00:33:26,320 --> 00:33:29,000 Speaker 1: That sounds very promising, right, that sounds like a very 632 00:33:29,320 --> 00:33:32,200 Speaker 1: like promising path. And the fact that there's this wiggle 633 00:33:32,240 --> 00:33:38,560 Speaker 1: connection where wiggling or velocity movement for gravity like creates 634 00:33:38,640 --> 00:33:41,560 Speaker 1: this this field is very interesting. 635 00:33:42,000 --> 00:33:43,880 Speaker 4: I just I feel a butt is common. 636 00:33:44,240 --> 00:33:45,560 Speaker 3: There is a big butt, A. 637 00:33:45,720 --> 00:33:50,800 Speaker 1: Man, I knew I like big butts, and I cannot lie. 638 00:33:52,680 --> 00:33:53,440 Speaker 3: Now that's a reference. 639 00:33:53,480 --> 00:33:55,400 Speaker 4: I hope everybody hopefully Stelia. 640 00:33:55,760 --> 00:33:58,640 Speaker 3: The other brothers can't deny. Well, the thing that the 641 00:33:58,680 --> 00:34:03,160 Speaker 3: other brothers can deny is that this works in difficult situations. 642 00:34:03,280 --> 00:34:06,400 Speaker 3: Like we said that you could take Einstein's rules and 643 00:34:06,440 --> 00:34:10,680 Speaker 3: you can express them in mathematical equations that look like electromagnetism. 644 00:34:11,440 --> 00:34:13,319 Speaker 3: But there was a butt there I left off, And 645 00:34:13,400 --> 00:34:16,399 Speaker 3: the butt is This only works if gravity is kind 646 00:34:16,400 --> 00:34:19,839 Speaker 3: of weak, like when the curvature of space time is 647 00:34:19,880 --> 00:34:23,280 Speaker 3: not very strong, when you're like far from any intense mass, 648 00:34:23,280 --> 00:34:25,640 Speaker 3: when you're far away from a black hole, for example, 649 00:34:25,719 --> 00:34:28,800 Speaker 3: or even from the Sun, then this works pretty well. 650 00:34:29,080 --> 00:34:31,640 Speaker 3: But when the curvature of space time gets more intense, 651 00:34:31,960 --> 00:34:35,040 Speaker 3: this breaks down. Like the equations are just too complicated, 652 00:34:35,080 --> 00:34:37,560 Speaker 3: too intense. We have no way to fit them into 653 00:34:37,600 --> 00:34:41,439 Speaker 3: these boxes to make them look like electromagnetism. In order 654 00:34:41,480 --> 00:34:44,040 Speaker 3: to do that, to take the complicated Tensor equations of 655 00:34:44,040 --> 00:34:47,480 Speaker 3: general relativity and to make them look like electromagnetism, you 656 00:34:47,520 --> 00:34:49,319 Speaker 3: have to make a bunch of assumptions, and one of 657 00:34:49,320 --> 00:34:53,200 Speaker 3: those assumptions is gravity is pretty weak. So basically what's 658 00:34:53,200 --> 00:34:56,000 Speaker 3: happened here is you've avoided the hard problem. You know, 659 00:34:56,080 --> 00:34:59,080 Speaker 3: the hard problem of making quantum gravity work was figuring 660 00:34:59,120 --> 00:35:03,720 Speaker 3: out what happened when gravitons amid other gravitons amid other gravitons. Basically, 661 00:35:03,920 --> 00:35:06,160 Speaker 3: when gravity gets very very strong and it can no 662 00:35:06,239 --> 00:35:10,280 Speaker 3: longer be neglected, and that's exactly the situation that gravito 663 00:35:10,400 --> 00:35:14,840 Speaker 3: electromagnetism doesn't know how to answer. So it's some progress 664 00:35:14,920 --> 00:35:16,640 Speaker 3: in the sense of like, hmm, you found some cool 665 00:35:16,680 --> 00:35:19,960 Speaker 3: connections between these theories, but only in the easy parts, 666 00:35:20,320 --> 00:35:22,319 Speaker 3: not in the hard parts at all. When you get 667 00:35:22,320 --> 00:35:24,840 Speaker 3: to the hard part of gravity being very strong and 668 00:35:24,880 --> 00:35:28,120 Speaker 3: every graviton is emitting ten other gravitons, then this breaks 669 00:35:28,160 --> 00:35:30,919 Speaker 3: down and it doesn't help us at all. So it's 670 00:35:30,960 --> 00:35:34,200 Speaker 3: like an interesting island of understanding, but it doesn't make 671 00:35:34,280 --> 00:35:37,320 Speaker 3: any progress on the really hard part of the problem 672 00:35:37,600 --> 00:35:40,560 Speaker 3: of describing gravity as a quantum theory when gravity is 673 00:35:40,640 --> 00:35:41,920 Speaker 3: very very strong. 674 00:35:41,719 --> 00:35:45,560 Speaker 1: But could it be revealing something about gravity still, like 675 00:35:46,040 --> 00:35:50,800 Speaker 1: maybe that there is a significant difference between a strong 676 00:35:51,800 --> 00:35:54,080 Speaker 1: or large amount of gravity, like the gravity of the 677 00:35:54,120 --> 00:35:56,319 Speaker 1: Sun versus the Earth. If there is some kind of 678 00:35:56,320 --> 00:36:00,560 Speaker 1: fundamental difference between like weak levels of gravity and strong 679 00:36:00,680 --> 00:36:04,360 Speaker 1: levels of gravity, that seems like that could itself be 680 00:36:05,239 --> 00:36:08,280 Speaker 1: an interesting kind of finding, even if it still doesn't 681 00:36:08,320 --> 00:36:12,680 Speaker 1: solve the bigger question of how to merge those concepts. 682 00:36:12,920 --> 00:36:14,520 Speaker 3: Yeah, exactly, And that was the point I was trying 683 00:36:14,520 --> 00:36:18,040 Speaker 3: to make earlier that even intermedia progress is progress. You 684 00:36:18,080 --> 00:36:20,239 Speaker 3: don't have to know if this is going to fundamentally 685 00:36:20,239 --> 00:36:23,160 Speaker 3: solve the question of quantum mechanical gravity for it to 686 00:36:23,200 --> 00:36:25,319 Speaker 3: be cool that you figured something out, that you've made 687 00:36:25,320 --> 00:36:28,920 Speaker 3: some headway, you found some island of understanding whether it 688 00:36:28,960 --> 00:36:31,200 Speaker 3: actually connects to the mainland and reveals all the deep 689 00:36:31,239 --> 00:36:33,600 Speaker 3: secrets we don't know yet. But that doesn't mean it's 690 00:36:33,640 --> 00:36:36,479 Speaker 3: not worth doing and not worth exploring. Right, we've made 691 00:36:36,480 --> 00:36:38,600 Speaker 3: it to this stage where we've been able to accomplish 692 00:36:38,680 --> 00:36:42,960 Speaker 3: this connection between electromagnetism and gravity. It might be that 693 00:36:43,200 --> 00:36:45,960 Speaker 3: hunting around and digging around and poking in various directions. 694 00:36:46,400 --> 00:36:48,520 Speaker 3: Lets us build from this right that we can go 695 00:36:48,600 --> 00:36:51,440 Speaker 3: from here to figure out how to describe strong gravity. 696 00:36:51,680 --> 00:36:54,040 Speaker 3: Nobody knows how to do that yet, but this is 697 00:36:54,080 --> 00:36:56,920 Speaker 3: like another avenue of attack. This gives us another way 698 00:36:56,960 --> 00:36:59,200 Speaker 3: to think about it. At least it might be a 699 00:36:59,200 --> 00:37:01,920 Speaker 3: total dead end or might be the wave of the future. 700 00:37:02,040 --> 00:37:04,759 Speaker 3: We haven't figured that out yet. It's on the forefront 701 00:37:04,800 --> 00:37:05,600 Speaker 3: of knowledge. 702 00:37:05,840 --> 00:37:08,719 Speaker 4: I mean, let's go with not being a dead end. 703 00:37:09,520 --> 00:37:13,799 Speaker 1: We'll take a quick break and try to keep up 704 00:37:13,840 --> 00:37:17,799 Speaker 1: the optimism that this is actually going towards finding a 705 00:37:17,960 --> 00:37:22,319 Speaker 1: fundamental answer that'll change everyone's lives. And we're probably not 706 00:37:22,320 --> 00:37:24,400 Speaker 1: going to figure it out in the ad break, but 707 00:37:24,719 --> 00:37:40,080 Speaker 1: you know, we'll think about it. So we are back. 708 00:37:40,760 --> 00:37:46,200 Speaker 1: We have not yet solved how to weave together electromagnetism 709 00:37:46,600 --> 00:37:52,160 Speaker 1: and general relativity or gravity, but there has been some 710 00:37:52,320 --> 00:37:56,400 Speaker 1: interesting progress that has been made that is perhaps instructive 711 00:37:56,440 --> 00:38:02,160 Speaker 1: and perhaps interesting. So we had that issue that these 712 00:38:02,880 --> 00:38:07,520 Speaker 1: equations when gravity is weak, they seem to kind of align, 713 00:38:07,640 --> 00:38:11,200 Speaker 1: like you have the equations associated with general relativity and 714 00:38:11,239 --> 00:38:15,160 Speaker 1: then Maxwell's equations that looked similar then when gravity got 715 00:38:15,239 --> 00:38:19,680 Speaker 1: strong like the sun or a black hole, that kind 716 00:38:19,680 --> 00:38:22,560 Speaker 1: of broke down. It no longer worked in that way. 717 00:38:23,400 --> 00:38:27,480 Speaker 1: So is there another sort of angle of attack that 718 00:38:27,640 --> 00:38:28,560 Speaker 1: is being explored. 719 00:38:28,760 --> 00:38:31,200 Speaker 3: Yeah, people are trying so many different things at once, 720 00:38:31,320 --> 00:38:32,880 Speaker 3: and you know, this is the way we make progress. 721 00:38:32,960 --> 00:38:34,600 Speaker 3: You push your way through the jungle. Maybe you make 722 00:38:34,640 --> 00:38:36,200 Speaker 3: it all the way through. Maybe you run into somebody 723 00:38:36,200 --> 00:38:38,879 Speaker 3: else coming from the other direction right, and you can 724 00:38:39,000 --> 00:38:42,080 Speaker 3: join you two efforts. And so that's what's happening is 725 00:38:42,239 --> 00:38:44,879 Speaker 3: a bunch of people are working on trying to make 726 00:38:45,040 --> 00:38:50,040 Speaker 3: gravity look like electromagnetism. So that's the gravito electromagnetic approach 727 00:38:50,040 --> 00:38:52,560 Speaker 3: that we just talked about. But some people are working 728 00:38:52,560 --> 00:38:55,760 Speaker 3: in the other direction. They're saying, let's not make gravity 729 00:38:55,800 --> 00:39:01,919 Speaker 3: look like electromagnetism, let's make electromagnetism look like gravity. Einstein's 730 00:39:01,960 --> 00:39:05,560 Speaker 3: big idea was let's not think of gravity as a force, 731 00:39:05,800 --> 00:39:08,520 Speaker 3: let's think of it as the curvature of space time. 732 00:39:08,920 --> 00:39:11,320 Speaker 3: And so people are wondering, like, can we extend that idea? 733 00:39:11,400 --> 00:39:15,040 Speaker 3: Can we also do that for electromagnetism. Remember that the 734 00:39:15,080 --> 00:39:18,200 Speaker 3: way Einstein did this is he said, look, it feels 735 00:39:18,320 --> 00:39:21,560 Speaker 3: like there's a force between you and the Earth. Newton's 736 00:39:21,560 --> 00:39:24,759 Speaker 3: description of gravity as a force is compelling because when 737 00:39:24,760 --> 00:39:26,840 Speaker 3: you throw a ball in the air, it falls to 738 00:39:26,880 --> 00:39:28,960 Speaker 3: the Earth and it looks like it's getting pulled on. Right, 739 00:39:28,960 --> 00:39:32,279 Speaker 3: we have this experience of gravity as a force. But 740 00:39:32,280 --> 00:39:34,440 Speaker 3: he said that it's not actually a force. That's something 741 00:39:34,480 --> 00:39:37,320 Speaker 3: of an illusion. What's happening when you toss a ball 742 00:39:37,760 --> 00:39:41,440 Speaker 3: is that you're releasing it into free fall. Space itself 743 00:39:41,520 --> 00:39:44,160 Speaker 3: is curved in the vicinity of mass, so there's a 744 00:39:44,239 --> 00:39:47,200 Speaker 3: natural path for objects to follow in curved space time. 745 00:39:47,800 --> 00:39:51,440 Speaker 3: So the ball naturally falls towards the center of the Earth. 746 00:39:51,840 --> 00:39:55,320 Speaker 3: So Newton's picture is there's a force pulling on the ball, 747 00:39:55,680 --> 00:39:57,360 Speaker 3: and then it hits the Earth and it stops it 748 00:39:57,400 --> 00:40:01,120 Speaker 3: because the Earth is balancing that force of gravity. Einstein's 749 00:40:01,120 --> 00:40:04,120 Speaker 3: picture is different. Einstein says, when the ball is in 750 00:40:04,160 --> 00:40:07,080 Speaker 3: the air, it's in freefall. There is no force on 751 00:40:07,160 --> 00:40:09,880 Speaker 3: the ball at all. It's just following the motion of 752 00:40:09,880 --> 00:40:12,759 Speaker 3: space and time. And then the Earth stops it because 753 00:40:12,760 --> 00:40:15,760 Speaker 3: the Earth itself is providing a force. It's accelerating against 754 00:40:15,800 --> 00:40:17,680 Speaker 3: that natural motion of space time. 755 00:40:17,960 --> 00:40:21,040 Speaker 1: Yeah, and I think you've told me this is actually measurable, right, 756 00:40:21,120 --> 00:40:26,440 Speaker 1: that there is acceleration acting when you are standing on 757 00:40:26,840 --> 00:40:27,400 Speaker 1: the floor. 758 00:40:27,680 --> 00:40:29,959 Speaker 3: Exactly, if you jump off a building instead of the ball, 759 00:40:30,040 --> 00:40:32,399 Speaker 3: and you take a scale with you, and as you're 760 00:40:32,440 --> 00:40:35,360 Speaker 3: falling through the air, hurtling towards the earth, you stand 761 00:40:35,400 --> 00:40:37,239 Speaker 3: on the scale, what are you going to measure? You're 762 00:40:37,239 --> 00:40:39,960 Speaker 3: going to measure nothing, right. You have no weight, and 763 00:40:40,000 --> 00:40:43,080 Speaker 3: that's because you're in freefall. There's no acceleration there. You're 764 00:40:43,080 --> 00:40:45,840 Speaker 3: not measuring anything. If you're standing on the surface of 765 00:40:45,840 --> 00:40:47,560 Speaker 3: the Earth and you stand on the scale, then you 766 00:40:47,560 --> 00:40:50,319 Speaker 3: measure your weight. That's where there's a force, right, So 767 00:40:50,320 --> 00:40:53,200 Speaker 3: there really is no force on you when you are 768 00:40:53,200 --> 00:40:56,160 Speaker 3: in freefall. There's a force on you when you're standing 769 00:40:56,200 --> 00:40:58,480 Speaker 3: on the surface of the earth. That's the Earth pushing 770 00:40:58,560 --> 00:41:02,000 Speaker 3: up against that natural motion. So the explanation is that 771 00:41:02,040 --> 00:41:04,279 Speaker 3: there is no force there. There's just a curvature of 772 00:41:04,280 --> 00:41:06,799 Speaker 3: space and time. And we couldn't see that curvature, and 773 00:41:06,840 --> 00:41:09,440 Speaker 3: that's why it looks to us like there is a force. 774 00:41:10,040 --> 00:41:12,799 Speaker 1: Having this as the theory about gravity, like, how do 775 00:41:12,880 --> 00:41:17,560 Speaker 1: you then fit the quantum forces into this framework, right, 776 00:41:17,600 --> 00:41:21,200 Speaker 1: because like that seems fundamentally different. Those are forces, they're 777 00:41:21,200 --> 00:41:24,200 Speaker 1: pulling or pushing against each other. How does that fit 778 00:41:24,320 --> 00:41:27,560 Speaker 1: into this kind of idea of gravity being like the 779 00:41:27,719 --> 00:41:32,440 Speaker 1: shape of existence, which sounds it's hard for me to 780 00:41:32,840 --> 00:41:34,640 Speaker 1: kind of think about that, right, like the shape of 781 00:41:34,640 --> 00:41:38,560 Speaker 1: the universe, the shape of the fabric of the universe, 782 00:41:38,560 --> 00:41:40,160 Speaker 1: and then we're just kind of falling along it. 783 00:41:40,760 --> 00:41:42,120 Speaker 4: And then you have these particles. 784 00:41:42,320 --> 00:41:46,759 Speaker 1: Have we observed anything in particles that could sort of 785 00:41:46,800 --> 00:41:48,880 Speaker 1: fit within that framework. 786 00:41:48,760 --> 00:41:51,160 Speaker 3: So we haven't observed anything yet, but there are some 787 00:41:51,400 --> 00:41:55,640 Speaker 3: theoretical ideas. The idea is to say, well, maybe electromagnetism 788 00:41:55,680 --> 00:41:58,359 Speaker 3: also isn't the force. Maybe it just looks like a 789 00:41:58,400 --> 00:42:02,200 Speaker 3: force and it's actually the result of a second kind 790 00:42:02,360 --> 00:42:05,520 Speaker 3: of curvature. So we have like first kind of curvature 791 00:42:05,600 --> 00:42:08,480 Speaker 3: is Einstein's curvature of space time that gives us the 792 00:42:08,520 --> 00:42:11,880 Speaker 3: apparent force of gravity. If space can also be curved 793 00:42:11,920 --> 00:42:15,440 Speaker 3: in another way, and that curvature gives us the appearance 794 00:42:15,800 --> 00:42:19,040 Speaker 3: of the force of electromagnetism. And in order to have 795 00:42:19,120 --> 00:42:23,440 Speaker 3: curvature in another way, you need more dimensions of space 796 00:42:23,560 --> 00:42:26,839 Speaker 3: and time. The idea is, like einstein space is three 797 00:42:26,880 --> 00:42:29,560 Speaker 3: plus one dimensions. You start with one dimension, which is 798 00:42:29,600 --> 00:42:32,560 Speaker 3: a line you draw a second dimension, which is perpendicular 799 00:42:32,640 --> 00:42:34,920 Speaker 3: to that. Now you have like a plane. You can 800 00:42:34,960 --> 00:42:37,400 Speaker 3: add a third dimension which is perpendicular to both of 801 00:42:37,480 --> 00:42:40,160 Speaker 3: the first two, and that gives you like three D 802 00:42:40,360 --> 00:42:43,480 Speaker 3: space right where each of those three lines are perpendicular 803 00:42:43,520 --> 00:42:46,239 Speaker 3: to each other. And that's it. There's no more room 804 00:42:46,280 --> 00:42:49,480 Speaker 3: to add another line perpendicular to all three. 805 00:42:49,440 --> 00:42:51,919 Speaker 4: Right, because space, Yeah, it doesn't work. 806 00:42:53,600 --> 00:42:55,640 Speaker 3: It's sort of crazy in mind bending. And I remember 807 00:42:55,680 --> 00:42:57,520 Speaker 3: as like an eight year old trying to imagine that's 808 00:42:57,600 --> 00:43:00,440 Speaker 3: fourth dimension but not being able to do it. But 809 00:43:00,560 --> 00:43:03,160 Speaker 3: we do think of time as sort of a fourth dimension. 810 00:43:03,360 --> 00:43:06,840 Speaker 3: How those three change. So Einstein space is four dimensional, 811 00:43:07,400 --> 00:43:09,839 Speaker 3: but we can extend it by adding another dimension of 812 00:43:09,880 --> 00:43:13,960 Speaker 3: space and having that curvature be in that additional dimension, 813 00:43:14,000 --> 00:43:16,919 Speaker 3: that fifth dimension. And you might ask, well, I can't 814 00:43:16,960 --> 00:43:19,440 Speaker 3: see that dimension. I can't imagine where that dimension would be. 815 00:43:19,480 --> 00:43:22,280 Speaker 3: How does that even work? Yeah, And this fifth dimension 816 00:43:22,320 --> 00:43:24,400 Speaker 3: is sort of similar to the way we think about time, 817 00:43:24,920 --> 00:43:27,280 Speaker 3: or like time we think about as the fourth dimension. 818 00:43:27,680 --> 00:43:32,319 Speaker 3: Imagine three dimensional space and then imagine that changing through time. Right, 819 00:43:32,400 --> 00:43:34,840 Speaker 3: save your full three dimensional space, But now you have 820 00:43:34,920 --> 00:43:38,000 Speaker 3: like another axis along which that three dimensional space is 821 00:43:38,120 --> 00:43:43,360 Speaker 3: changing so to imagine another dimension of space itself. Imagine 822 00:43:43,400 --> 00:43:45,759 Speaker 3: three dimensional space and then imagine a bunch of copies 823 00:43:45,800 --> 00:43:48,200 Speaker 3: of it. And this new dimension is not like the 824 00:43:48,239 --> 00:43:51,200 Speaker 3: original three. Instead of going on forever, it's like a 825 00:43:51,239 --> 00:43:54,640 Speaker 3: little loop. It's more like in polar coordinates, how you 826 00:43:54,680 --> 00:43:57,120 Speaker 3: have an angle and the angle can't go from zero 827 00:43:57,120 --> 00:43:59,200 Speaker 3: to infinity, just goes from zero to three hundred and 828 00:43:59,239 --> 00:44:01,560 Speaker 3: sixty degrees and it goes back to zero again. Right, 829 00:44:02,239 --> 00:44:05,120 Speaker 3: Imagine a new dimension of space that's sort of similar. 830 00:44:05,200 --> 00:44:08,160 Speaker 3: It has a maximum length, it's a circle instead of 831 00:44:08,200 --> 00:44:11,080 Speaker 3: an infinite line. Take three D space and sort of 832 00:44:11,120 --> 00:44:13,960 Speaker 3: move it around this circle. That's how we imagine a 833 00:44:14,080 --> 00:44:18,040 Speaker 3: universe with four spatial dimensions, the first three that are normal, 834 00:44:18,280 --> 00:44:20,480 Speaker 3: and then this weird rolled up dimension. 835 00:44:20,960 --> 00:44:24,600 Speaker 1: Is it like when your Windows computer crashes and you're 836 00:44:24,800 --> 00:44:27,600 Speaker 1: dragging like your cursor or a window around, and then 837 00:44:27,640 --> 00:44:30,160 Speaker 1: there's a bunch of little copies of that that all 838 00:44:30,200 --> 00:44:32,000 Speaker 1: get stacked up and messed up. 839 00:44:32,840 --> 00:44:36,120 Speaker 4: Is that what we're talking about here exactly? 840 00:44:37,120 --> 00:44:39,239 Speaker 3: Or like when you win solitaire and the cards all 841 00:44:39,280 --> 00:44:42,120 Speaker 3: stack on top of each other. It's difficult to imagine 842 00:44:42,200 --> 00:44:44,680 Speaker 3: because we're used to three D space and we think 843 00:44:44,719 --> 00:44:47,960 Speaker 3: in three dimensions, and so squeezing that fourth dimension into 844 00:44:47,960 --> 00:44:51,680 Speaker 3: your brain is really a challenge. But mathematically it allows 845 00:44:51,719 --> 00:44:54,839 Speaker 3: something very cool. It allows you to have another kind 846 00:44:54,880 --> 00:44:58,880 Speaker 3: of curvature. A curvature in this new dimension might be 847 00:44:58,920 --> 00:45:03,200 Speaker 3: able to explain what we see as the force of electromagnetism. 848 00:45:03,360 --> 00:45:05,360 Speaker 3: So in this case, not just the curvature, but the 849 00:45:05,360 --> 00:45:09,440 Speaker 3: whole dimension would be basically invisible to us. This is 850 00:45:09,440 --> 00:45:11,480 Speaker 3: an ancient idea in physics. It goes all the way 851 00:45:11,520 --> 00:45:15,040 Speaker 3: back to nineteen nineteen. The guy Theodor Cluza came up 852 00:45:15,080 --> 00:45:17,399 Speaker 3: with this, just after Einstein came up with his idea 853 00:45:17,400 --> 00:45:20,359 Speaker 3: of relativity, and then a few years later a guy 854 00:45:20,440 --> 00:45:23,239 Speaker 3: named Oscar Klein turned it into a quantum theory in 855 00:45:23,320 --> 00:45:26,680 Speaker 3: nineteen twenty six. And try to calculate the size of 856 00:45:26,719 --> 00:45:29,440 Speaker 3: this new fifth dimension and figured out how to be 857 00:45:29,480 --> 00:45:32,480 Speaker 3: like twenty times the plank length, which means it's like 858 00:45:32,760 --> 00:45:36,040 Speaker 3: super duper tiny. It's like ten to the minus thirty 859 00:45:36,080 --> 00:45:39,040 Speaker 3: five meters long. So this seemed really exciting. 860 00:45:39,160 --> 00:45:41,719 Speaker 1: I have so many questions just about that, like what 861 00:45:41,760 --> 00:45:45,560 Speaker 1: do you mean calculating the size of a dimension right? 862 00:45:46,120 --> 00:45:50,279 Speaker 3: Like, remember that this new dimension is not infinite, we 863 00:45:50,320 --> 00:45:51,879 Speaker 3: think that you can go as far as you want 864 00:45:51,920 --> 00:45:53,600 Speaker 3: in X or and y, R and z. But this 865 00:45:53,680 --> 00:45:57,280 Speaker 3: new dimension is a loop, which means it has a length. 866 00:45:57,800 --> 00:46:01,320 Speaker 3: Now there's a maximum distance in this dimension. It's unlike 867 00:46:01,400 --> 00:46:04,040 Speaker 3: the other ones in a really weird way, and that 868 00:46:04,080 --> 00:46:06,040 Speaker 3: means that you can calculate, like, well, how big could 869 00:46:06,040 --> 00:46:08,160 Speaker 3: it be? What is the radius of curvature? What is 870 00:46:08,200 --> 00:46:12,160 Speaker 3: the length around this dimension? So it's very different in 871 00:46:12,200 --> 00:46:15,879 Speaker 3: a really counterintuitive way. And then Einstein got to work 872 00:46:15,920 --> 00:46:17,520 Speaker 3: on it, and he was like, all right, this is exciting. 873 00:46:18,120 --> 00:46:19,960 Speaker 4: I trust him more than I trust me to think 874 00:46:19,960 --> 00:46:20,399 Speaker 4: about it. 875 00:46:21,840 --> 00:46:24,000 Speaker 3: He thought, maybe this is exciting. Maybe I can make 876 00:46:24,040 --> 00:46:27,440 Speaker 3: this work. Maybe I can explain all of electromagnetism using 877 00:46:27,480 --> 00:46:30,799 Speaker 3: curvature in this new fifth dimension. And yeah, he died 878 00:46:30,840 --> 00:46:33,360 Speaker 3: before he found and people had been working on it 879 00:46:33,400 --> 00:46:35,960 Speaker 3: for a long time and nobody's been able to crack it. 880 00:46:36,520 --> 00:46:39,040 Speaker 3: There are some versions of this theory which sort of work, 881 00:46:39,520 --> 00:46:41,160 Speaker 3: but they all predict that we would have seen a 882 00:46:41,200 --> 00:46:44,319 Speaker 3: bunch of new particles. They predict that electrons would like 883 00:46:44,640 --> 00:46:47,759 Speaker 3: vibrate in this other dimension, and they would vibrate in 884 00:46:47,840 --> 00:46:50,640 Speaker 3: different ways, so you would see like different versions of 885 00:46:50,680 --> 00:46:53,360 Speaker 3: the electron the way like a string can vibrate, but 886 00:46:53,440 --> 00:46:56,040 Speaker 3: it can vibrate like one mode or two modes, or 887 00:46:56,040 --> 00:46:59,480 Speaker 3: three modes or four modes. Electrons could vibrate in this 888 00:46:59,520 --> 00:47:01,920 Speaker 3: other demands in various ways, and you would see like 889 00:47:02,160 --> 00:47:05,520 Speaker 3: heavier and heavier versions of the electron, where the heavy 890 00:47:05,520 --> 00:47:08,880 Speaker 3: ones are like vibrating in this new dimension with more energy, 891 00:47:08,880 --> 00:47:11,960 Speaker 3: which gives them effectively more mass. But we haven't seen 892 00:47:12,000 --> 00:47:14,840 Speaker 3: any heavy electrons, or any heavy muons, or any heavy 893 00:47:14,880 --> 00:47:17,960 Speaker 3: versions of these other particles at all. People thought for 894 00:47:17,960 --> 00:47:20,240 Speaker 3: a while, oh, maybe the muon is a heavy version 895 00:47:20,239 --> 00:47:22,880 Speaker 3: of the electron, and that's actually like, you know, something 896 00:47:22,960 --> 00:47:25,719 Speaker 3: vibrating in this new dimension. But that doesn't quite work 897 00:47:25,760 --> 00:47:28,040 Speaker 3: out because the electron and the muon feel the weak 898 00:47:28,080 --> 00:47:31,480 Speaker 3: force a little bit differently. So the bottom line is 899 00:47:31,680 --> 00:47:35,920 Speaker 3: it's an exciting direction theoretically to try to make electromagnetism 900 00:47:35,960 --> 00:47:39,840 Speaker 3: work in this clusive cline theory, but it's made predictions 901 00:47:39,880 --> 00:47:42,680 Speaker 3: that haven't been born out in the data, and so 902 00:47:42,840 --> 00:47:44,000 Speaker 3: it's not so promising. 903 00:47:44,520 --> 00:47:47,959 Speaker 1: Well, we need to make a time machine go back 904 00:47:47,960 --> 00:47:51,359 Speaker 1: in time, and then ask Einstein, first of all, how 905 00:47:51,400 --> 00:47:54,160 Speaker 1: to make a time machine so that in the future 906 00:47:54,239 --> 00:47:56,160 Speaker 1: we can go back in time and talk to them 907 00:47:57,360 --> 00:48:00,080 Speaker 1: and then present them with all of this information. 908 00:48:00,160 --> 00:48:02,839 Speaker 4: Or maybe, uh, there will be a. 909 00:48:02,840 --> 00:48:08,840 Speaker 1: New kind of Einstein, or collectively instead of one super genius, 910 00:48:08,920 --> 00:48:13,160 Speaker 1: just a bunch of very smart people working together figuring 911 00:48:13,200 --> 00:48:14,880 Speaker 1: this out exactly. 912 00:48:14,920 --> 00:48:17,960 Speaker 3: But it's promising. It's exciting that people are trying to 913 00:48:17,960 --> 00:48:20,520 Speaker 3: push their way through the theoretical jungle. You know, until 914 00:48:20,560 --> 00:48:22,279 Speaker 3: we figure out how to make a black hole here 915 00:48:22,320 --> 00:48:25,040 Speaker 3: on Earth, or we've come up with some clever quantum 916 00:48:25,040 --> 00:48:28,920 Speaker 3: gravity experiment that lets us see particles feeling gravity and 917 00:48:29,000 --> 00:48:33,160 Speaker 3: understand whether they're like bending space time probabilistically, or whether 918 00:48:33,239 --> 00:48:36,920 Speaker 3: gravity collapses their wave functions, or what's going on, we 919 00:48:36,960 --> 00:48:40,320 Speaker 3: can only make progress theoretically. That means trying to find 920 00:48:40,400 --> 00:48:45,120 Speaker 3: mathematical relationships between these theories, either making electromagnetism look more 921 00:48:45,200 --> 00:48:49,719 Speaker 3: like gravity or make gravity look more like electromagnetism. So far, 922 00:48:49,880 --> 00:48:52,160 Speaker 3: both paths have been sort of stuck in the jungle. 923 00:48:52,200 --> 00:48:54,920 Speaker 3: But maybe one day people will find a connection between 924 00:48:54,960 --> 00:48:56,919 Speaker 3: them and will all be illuminated. 925 00:48:57,239 --> 00:49:00,319 Speaker 1: That is beautiful, but you do also keep breezing past 926 00:49:00,360 --> 00:49:02,720 Speaker 1: this plan to make up a black hole on Earth. 927 00:49:03,400 --> 00:49:04,680 Speaker 4: That's feel sangerous. 928 00:49:04,719 --> 00:49:08,040 Speaker 3: To me, it is very dangerous, but also potentially we 929 00:49:08,040 --> 00:49:10,200 Speaker 3: could learn a lot about the universe, so you know, 930 00:49:10,480 --> 00:49:11,640 Speaker 3: may be worth a risk. 931 00:49:11,960 --> 00:49:15,720 Speaker 4: Yeah, ultimate knowledge right before oblivion. Sign me up. 932 00:49:18,680 --> 00:49:21,480 Speaker 3: Sounds good. We'll stay tuned for more hints about potential 933 00:49:21,560 --> 00:49:24,960 Speaker 3: ultimate knowledge about the universe, just before you get sucked 934 00:49:25,000 --> 00:49:28,000 Speaker 3: into oblivion. Thanks so very much Katie for joining me 935 00:49:28,080 --> 00:49:31,240 Speaker 3: on this journey of theoretical understanding, and thanks to everybody 936 00:49:31,280 --> 00:49:39,280 Speaker 3: for tuning in. Tune in next time for more science 937 00:49:39,280 --> 00:49:42,080 Speaker 3: and curiosity. Come find us on social media where we 938 00:49:42,120 --> 00:49:46,360 Speaker 3: answer questions and post videos. We're on Twitter, Discord, Instant, 939 00:49:46,400 --> 00:49:50,120 Speaker 3: and now TikTok. Thanks for listening, and remember that Daniel 940 00:49:50,120 --> 00:49:53,600 Speaker 3: and Jorge Explain the Universe is a production of iHeartRadio. 941 00:49:53,880 --> 00:49:59,040 Speaker 3: For more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, 942 00:49:59,120 --> 00:50:01,480 Speaker 3: or wherever you like listen to your favorite shows.