1 00:00:08,680 --> 00:00:11,360 Speaker 1: Hey, Katie, did you know that if you stick any 2 00:00:11,440 --> 00:00:14,480 Speaker 1: two science worse together you get a great science fiction 3 00:00:14,520 --> 00:00:17,480 Speaker 1: movie title. Really? Is it really that easy? Oh yeah, 4 00:00:17,520 --> 00:00:22,439 Speaker 1: just give it a shot. Okay, let's see Quantum Hamster Boom. 5 00:00:22,520 --> 00:00:27,520 Speaker 1: I can see that whole movie in my mind alway, Yeah, okay, okay, 6 00:00:27,520 --> 00:00:31,000 Speaker 1: what about Alligator Crystal? I love it? Want to see 7 00:00:31,040 --> 00:00:36,680 Speaker 1: that one. Let's do time, Pump. I'm calling Netflix and 8 00:00:36,760 --> 00:00:54,800 Speaker 1: set up a pitch meeting right now. Hi. I'm Daniel. 9 00:00:54,880 --> 00:00:57,760 Speaker 1: I'm a particle physicist, and I really would like to 10 00:00:57,760 --> 00:01:01,160 Speaker 1: write a science fiction movie someday. And I am Katie. 11 00:01:01,520 --> 00:01:06,240 Speaker 1: I am a science podcaster, and I am already writing 12 00:01:06,280 --> 00:01:10,160 Speaker 1: dialogue for Quantum Hamster in my head. And Welcome to 13 00:01:10,160 --> 00:01:13,960 Speaker 1: the podcast Daniel and Jorge Explain the Universe, a production 14 00:01:14,200 --> 00:01:16,679 Speaker 1: of I Heart Radio in which we take you on 15 00:01:16,720 --> 00:01:20,240 Speaker 1: a tour of everything that's amazing in the universe, everything 16 00:01:20,240 --> 00:01:23,319 Speaker 1: that's out there doing crazy stuff you couldn't imagine, and 17 00:01:23,400 --> 00:01:26,760 Speaker 1: all the weird quantum stuff happening at the particle level 18 00:01:27,040 --> 00:01:29,800 Speaker 1: and everything in between. But we want you to come 19 00:01:29,840 --> 00:01:32,559 Speaker 1: away from our podcast not just hearing about the crazy 20 00:01:32,600 --> 00:01:36,280 Speaker 1: stuff in the universe, but actually understanding it. And as 21 00:01:36,280 --> 00:01:38,440 Speaker 1: you might have guessed, Orge isn't with us today, but 22 00:01:38,480 --> 00:01:42,800 Speaker 1: instead we have a wonderful guest podcast host, Katie introduce 23 00:01:42,840 --> 00:01:45,840 Speaker 1: yourself to everybody. Hi, guys, I am Katie Golden. I'm 24 00:01:45,880 --> 00:01:49,600 Speaker 1: the host of Creature Feature, a podcast about animal and 25 00:01:49,800 --> 00:01:55,320 Speaker 1: human behavior. I studied psychology and evolutionary biology, so I 26 00:01:55,360 --> 00:01:59,440 Speaker 1: am very excited to take a journey into the physics 27 00:01:59,520 --> 00:02:03,760 Speaker 1: realm of things. I hope I can fill Jorges shoes 28 00:02:03,840 --> 00:02:06,400 Speaker 1: a little bit temporarily. Do you know what his shoe sizes. 29 00:02:07,440 --> 00:02:09,960 Speaker 1: He's a cartoonist, so he just draws really big, floppy 30 00:02:09,960 --> 00:02:14,120 Speaker 1: clown shoes and that'll be perfect for me. Well, you 31 00:02:14,120 --> 00:02:16,480 Speaker 1: guys should all check out. Creature Feature is a super 32 00:02:16,520 --> 00:02:19,160 Speaker 1: fun podcast, and Katie's a lot of fun, which is 33 00:02:19,240 --> 00:02:22,320 Speaker 1: why we invite her here as a guest host. And 34 00:02:22,360 --> 00:02:25,400 Speaker 1: you know, today's episode is all about how we understand 35 00:02:25,440 --> 00:02:28,360 Speaker 1: the universe and how we understand things like time, which 36 00:02:28,360 --> 00:02:30,960 Speaker 1: makes me wonder since you're an expert on creatures and 37 00:02:31,040 --> 00:02:35,840 Speaker 1: evolutionary behavior, do animals understand time? Katie? That's a really 38 00:02:35,880 --> 00:02:39,240 Speaker 1: good question. I'd say it depends on the animal, and 39 00:02:39,280 --> 00:02:43,160 Speaker 1: it depends on what you mean by understand a lot 40 00:02:43,200 --> 00:02:47,320 Speaker 1: of animals can kind of mark the passage of time 41 00:02:47,320 --> 00:02:51,320 Speaker 1: without possibly really understanding it. Like there's a great migration 42 00:02:51,360 --> 00:02:54,920 Speaker 1: of plankton that happens every day with the rising and 43 00:02:55,000 --> 00:02:57,079 Speaker 1: setting of the sun. But could you say that as 44 00:02:57,240 --> 00:03:01,760 Speaker 1: little zooplankton really understands time. I'm gonna say no, that's 45 00:03:01,800 --> 00:03:05,040 Speaker 1: a bold, controversial take. But yeah, it's really hard to 46 00:03:05,080 --> 00:03:07,960 Speaker 1: get inside of the heads of animals. That's a problem 47 00:03:08,240 --> 00:03:11,120 Speaker 1: talk about on my podcast. Well, I wouldn't be surprised 48 00:03:11,160 --> 00:03:14,360 Speaker 1: if animals like crows understood time. There's a group of 49 00:03:14,400 --> 00:03:17,560 Speaker 1: crows that seem to always gather outside my window, right 50 00:03:17,639 --> 00:03:19,640 Speaker 1: or like I'm two o'clock in the afternoon when I 51 00:03:19,639 --> 00:03:23,839 Speaker 1: have a big zoom meeting. Yeah, I think patterns are 52 00:03:23,960 --> 00:03:28,480 Speaker 1: really easy for animals to understand, especially the smart ones crows. 53 00:03:28,520 --> 00:03:30,680 Speaker 1: If you feed them, they'll come back and visit you 54 00:03:30,720 --> 00:03:33,840 Speaker 1: whenever you feed them, so they will learn your patterns, 55 00:03:33,960 --> 00:03:36,040 Speaker 1: much like a cat. You know how your cat wakes 56 00:03:36,080 --> 00:03:38,600 Speaker 1: you up just in time early in the morning for 57 00:03:38,680 --> 00:03:42,600 Speaker 1: you to feed them. They understand patterns. They will memorize 58 00:03:42,680 --> 00:03:48,720 Speaker 1: your rhythms and patterns for the best snacking opportunities. Well, 59 00:03:48,760 --> 00:03:50,320 Speaker 1: you know, I was wondering if you were going to 60 00:03:50,480 --> 00:03:55,000 Speaker 1: ask whether any animal understands time, even humans, because as 61 00:03:55,040 --> 00:03:58,320 Speaker 1: you might know, time is a slippery topic and it's 62 00:03:58,360 --> 00:04:00,680 Speaker 1: something a lot of our listeners ask us to talk 63 00:04:00,680 --> 00:04:03,920 Speaker 1: about because it's not something that even human physicists can 64 00:04:04,000 --> 00:04:07,160 Speaker 1: get our minds around. Why do we remember the past 65 00:04:07,200 --> 00:04:09,680 Speaker 1: and not the future? Why is there now? Is the 66 00:04:09,800 --> 00:04:12,880 Speaker 1: now actually real? Or is time just an illusion? All 67 00:04:12,920 --> 00:04:16,760 Speaker 1: of these really simple basic questions about time haven't yet 68 00:04:16,800 --> 00:04:20,320 Speaker 1: been answered. So wait is time? When we're talking about 69 00:04:20,360 --> 00:04:23,159 Speaker 1: time though, is it just a human invention? Like we 70 00:04:23,279 --> 00:04:26,800 Speaker 1: made clocks, we have one o'clock to twelve o'clock, you know, 71 00:04:26,920 --> 00:04:29,560 Speaker 1: we kind of have this concept of time, like is 72 00:04:29,560 --> 00:04:32,800 Speaker 1: it not just our human invention or is there actually 73 00:04:32,960 --> 00:04:37,760 Speaker 1: a real thing of time outside of our little mickey 74 00:04:37,760 --> 00:04:40,160 Speaker 1: mouse watches. Yeah, it's a great question. There's a lot 75 00:04:40,240 --> 00:04:43,080 Speaker 1: of it that is invented by humanity, like units, you know, 76 00:04:43,200 --> 00:04:46,799 Speaker 1: one second, one minute, that's totally arbitrary, and an alien 77 00:04:46,839 --> 00:04:50,359 Speaker 1: species might invent something totally different. But in our understanding 78 00:04:50,400 --> 00:04:53,360 Speaker 1: of physics, time seems to be real, and we will 79 00:04:53,360 --> 00:04:56,000 Speaker 1: dig into that later in the podcast about the concept 80 00:04:56,040 --> 00:04:58,840 Speaker 1: of time in quantum mechanics. And the concept of time 81 00:04:58,839 --> 00:05:02,240 Speaker 1: in general relativity, which turned out to be totally fundamentally 82 00:05:02,320 --> 00:05:05,520 Speaker 1: different ideas of what time is. But yeah, we do 83 00:05:05,640 --> 00:05:08,159 Speaker 1: think the time is a feature of the universe. We 84 00:05:08,160 --> 00:05:11,000 Speaker 1: think it's something out there and real, but we won't 85 00:05:11,040 --> 00:05:13,479 Speaker 1: really know until we one day get to talk to 86 00:05:13,640 --> 00:05:17,120 Speaker 1: alien physicists and see if they even understand the concept 87 00:05:17,120 --> 00:05:20,680 Speaker 1: of time. That's so interesting. So there is an actual 88 00:05:21,640 --> 00:05:25,880 Speaker 1: cosmic time that is occurring that we sort of view 89 00:05:26,040 --> 00:05:29,200 Speaker 1: through our own little human lens, our sun dials and 90 00:05:29,240 --> 00:05:32,599 Speaker 1: our watches and our appointments, but that may not really 91 00:05:32,640 --> 00:05:35,080 Speaker 1: capture the whole truth about what time is. Yeah, or 92 00:05:35,120 --> 00:05:37,400 Speaker 1: it could be an illusion. It could be the time 93 00:05:37,920 --> 00:05:40,479 Speaker 1: is not something deep and fundamental to the universe. It 94 00:05:40,560 --> 00:05:42,800 Speaker 1: could be that it's sort of emerges that it's like 95 00:05:42,839 --> 00:05:46,680 Speaker 1: a special condition that only happens under certain circumstances, you know, 96 00:05:46,720 --> 00:05:49,760 Speaker 1: the way like ice forms sometimes in the universe, but 97 00:05:49,880 --> 00:05:52,400 Speaker 1: not always. You could have a universe without ice. That's 98 00:05:52,440 --> 00:05:55,640 Speaker 1: not a big deal. It might be the time isn't fundamental. 99 00:05:56,040 --> 00:05:58,479 Speaker 1: But we'll dig into all that on today's podcast. We 100 00:05:58,520 --> 00:06:01,520 Speaker 1: actually want to focus today on something even weirder than 101 00:06:01,640 --> 00:06:04,120 Speaker 1: just the question of time, which is a big puzzle 102 00:06:04,160 --> 00:06:06,480 Speaker 1: for physicist. We want to talk about something which has 103 00:06:06,520 --> 00:06:09,320 Speaker 1: been bopping around the Internet and creating a lot of 104 00:06:09,360 --> 00:06:13,839 Speaker 1: buzz recently. That's this topic of time crystals. Oh, that 105 00:06:13,960 --> 00:06:16,880 Speaker 1: sounds beautiful. What comes into your mind when I said it? 106 00:06:16,960 --> 00:06:20,840 Speaker 1: For his time crystals a bunch of clocks floating around 107 00:06:20,960 --> 00:06:25,919 Speaker 1: in a crystalline structure. All right, And so today on 108 00:06:25,920 --> 00:06:28,840 Speaker 1: the program we'll be asking and hopefully answering the question 109 00:06:33,960 --> 00:06:39,040 Speaker 1: what is a time crystal? So, Daniel, you asked people 110 00:06:39,120 --> 00:06:42,640 Speaker 1: on the internet what they thought. That's right. Folks out 111 00:06:42,680 --> 00:06:46,680 Speaker 1: there volunteered to speculate baselessly on the topic of the day, 112 00:06:46,760 --> 00:06:48,880 Speaker 1: just to give us a sense for what they knew 113 00:06:48,920 --> 00:06:51,479 Speaker 1: and what they didn't know. And so if you would 114 00:06:51,480 --> 00:06:55,480 Speaker 1: like to submit your baseless speculations for future podcast episodes, 115 00:06:55,560 --> 00:06:58,679 Speaker 1: please write to me two questions at Daniel and Jorge 116 00:06:58,960 --> 00:07:02,320 Speaker 1: dot com. And so here is what people had to say. 117 00:07:02,720 --> 00:07:06,320 Speaker 1: My only thought is that there are these points in 118 00:07:06,480 --> 00:07:11,880 Speaker 1: space that maybe our time markers, or there are certain 119 00:07:12,360 --> 00:07:17,520 Speaker 1: blocks of crystals that hold elements or signatures of certain 120 00:07:17,520 --> 00:07:21,480 Speaker 1: time events that you can look back on. That's easy. 121 00:07:22,000 --> 00:07:24,880 Speaker 1: Um made a whole Rick and Morty episode about those. 122 00:07:25,160 --> 00:07:27,640 Speaker 1: I don't know what time crystals are. Well, I know 123 00:07:27,680 --> 00:07:32,280 Speaker 1: about Courts is a crystal, and we use courts to 124 00:07:32,400 --> 00:07:37,920 Speaker 1: get precision timing and watches and things like that. Maybe 125 00:07:37,920 --> 00:07:40,200 Speaker 1: there's other crystals that can do the same thing. So 126 00:07:40,240 --> 00:07:42,400 Speaker 1: what do you think about those answers, Katie? I do 127 00:07:42,520 --> 00:07:45,960 Speaker 1: like the call back to Rick and Morty. They definitely 128 00:07:46,000 --> 00:07:49,080 Speaker 1: have a scientific approach to time with all of their 129 00:07:49,120 --> 00:07:51,400 Speaker 1: time travel episodes, do they? Though? Are you a Rick 130 00:07:51,440 --> 00:07:54,080 Speaker 1: and Morty fan? I like it it's a loaded question 131 00:07:54,120 --> 00:07:55,960 Speaker 1: to ask if you're a Rick and Morty fan, because 132 00:07:56,000 --> 00:07:59,000 Speaker 1: I think that there are some really hardcore fans out 133 00:07:59,000 --> 00:08:02,840 Speaker 1: there who will contends that you have to really understand 134 00:08:02,960 --> 00:08:05,280 Speaker 1: science to understand the show, and I just think it's 135 00:08:05,280 --> 00:08:07,600 Speaker 1: a fun show. Yeah, well, you know, I watch Rick 136 00:08:07,640 --> 00:08:11,200 Speaker 1: and Morty sometimes, but I'm a real stickler for getting 137 00:08:11,200 --> 00:08:14,400 Speaker 1: the science right when you're doing time travel, and that's 138 00:08:14,480 --> 00:08:17,520 Speaker 1: really hard. It's very difficult to have a narrative that 139 00:08:17,600 --> 00:08:20,120 Speaker 1: makes sense if you're also going backwards in time and 140 00:08:20,200 --> 00:08:23,120 Speaker 1: jumping all around, and so that sometimes gets the way 141 00:08:23,160 --> 00:08:25,920 Speaker 1: of me enjoying Rick and Morty. I see, you're real 142 00:08:26,000 --> 00:08:32,120 Speaker 1: stickler for those time travel plot holes that always pop up. Yeah, exactly. 143 00:08:32,559 --> 00:08:35,920 Speaker 1: Speaking of time, the focus of today's episode is this question, 144 00:08:36,040 --> 00:08:38,920 Speaker 1: what is a time crystal? I like some of these answers. 145 00:08:39,120 --> 00:08:42,599 Speaker 1: You know, we do use a crystal in watches sometimes 146 00:08:42,679 --> 00:08:45,200 Speaker 1: to tell time, right, crystals are at the heart of 147 00:08:45,200 --> 00:08:48,240 Speaker 1: a lot of watches on people's risks. How do they 148 00:08:48,400 --> 00:08:50,679 Speaker 1: work to tell time? Do you have just a little 149 00:08:50,760 --> 00:08:53,720 Speaker 1: crystal man in your watch going like it's about two thirty? 150 00:08:54,640 --> 00:08:56,880 Speaker 1: That's exactly how it works. You crack it open, you'll 151 00:08:56,920 --> 00:09:03,480 Speaker 1: spot we're writing a Rick and Morty episode. But that's 152 00:09:03,520 --> 00:09:05,920 Speaker 1: not actually the kind of time crystal that we're talking 153 00:09:05,920 --> 00:09:08,920 Speaker 1: about today. Today's episode is about something totally different. So 154 00:09:08,960 --> 00:09:11,559 Speaker 1: what kind of time crystal are we talking about? If 155 00:09:11,559 --> 00:09:14,199 Speaker 1: it's not a little crystal telling you what time it is. 156 00:09:14,480 --> 00:09:17,520 Speaker 1: The idea of a time crystal basically is an extension 157 00:09:17,880 --> 00:09:21,000 Speaker 1: of the idea of a space crystal. So let's first 158 00:09:21,000 --> 00:09:23,520 Speaker 1: talk about what a space crystal is, remind ourselves about 159 00:09:23,559 --> 00:09:26,080 Speaker 1: like the basic idea there, and then we'll try to 160 00:09:26,120 --> 00:09:30,120 Speaker 1: apply that concept to time crystals. Now, I'm imagining a 161 00:09:30,200 --> 00:09:33,240 Speaker 1: crystal floating through space, but I'm going to guess that's 162 00:09:33,280 --> 00:09:36,720 Speaker 1: probably not what it is. No, exactly that's exactly what 163 00:09:36,760 --> 00:09:39,640 Speaker 1: it is for a space crystal, right, A space crystal 164 00:09:39,760 --> 00:09:42,520 Speaker 1: is what it's just like a regular pattern and a 165 00:09:42,559 --> 00:09:44,400 Speaker 1: crystal like the kind of thing that you see like 166 00:09:44,440 --> 00:09:46,599 Speaker 1: a shiny gem or something else you would call a 167 00:09:46,640 --> 00:09:49,760 Speaker 1: crystal is if you zoom down into it and understood 168 00:09:49,800 --> 00:09:52,720 Speaker 1: it like at the molecular or the atomic level. The 169 00:09:52,760 --> 00:09:55,960 Speaker 1: way it's built is like a bunch of Lincoln logs 170 00:09:56,080 --> 00:10:00,439 Speaker 1: or something. You have regularly spaced atoms all end up 171 00:10:00,600 --> 00:10:03,200 Speaker 1: in like a three dimensional pattern. Right, It's that kind 172 00:10:03,200 --> 00:10:06,800 Speaker 1: of grid like structure. I always think of a sort 173 00:10:06,840 --> 00:10:09,920 Speaker 1: of a wafer kind of treat, maybe just because I'm hungry, 174 00:10:09,960 --> 00:10:13,400 Speaker 1: but it's those layers and layers of interlocking wafer like 175 00:10:13,960 --> 00:10:17,719 Speaker 1: molecular structures. Right, Yeah, exactly. You have wafer and then 176 00:10:17,760 --> 00:10:20,200 Speaker 1: you have caramel, then you have another wafer, then you 177 00:10:20,200 --> 00:10:23,120 Speaker 1: have chocolate. That's exactly the recipe for building your crystal. 178 00:10:23,240 --> 00:10:27,840 Speaker 1: Just making me hungrier, Katie's crystal cookies, I love it. Well. 179 00:10:27,840 --> 00:10:30,440 Speaker 1: Sugar is a crystal. Yes, sugar is a crystal. And 180 00:10:30,440 --> 00:10:33,559 Speaker 1: basically anything that's a crystal that has a regular pattern. 181 00:10:33,840 --> 00:10:36,000 Speaker 1: And that's the core concept that we have to understand 182 00:10:36,040 --> 00:10:39,600 Speaker 1: when we're talking about crystals. Basically, you're building a lattice. 183 00:10:39,880 --> 00:10:43,959 Speaker 1: You're taking a continuous symmetry right like space in itself 184 00:10:44,080 --> 00:10:46,680 Speaker 1: is the same everywhere. It doesn't really matter if you 185 00:10:46,720 --> 00:10:49,040 Speaker 1: take one step forward or a half step forward. The 186 00:10:49,080 --> 00:10:52,080 Speaker 1: same laws of physics reply, everything works the same way. 187 00:10:52,360 --> 00:10:55,640 Speaker 1: If you're gonna like juggle balls here, then you took 188 00:10:55,679 --> 00:10:58,000 Speaker 1: a step sideways, the same rules should apply, the same 189 00:10:58,080 --> 00:11:01,560 Speaker 1: juggling should work. A crystal takes that and sort of 190 00:11:01,600 --> 00:11:05,560 Speaker 1: breaks that symmetry into something discreet. So now the universe 191 00:11:05,800 --> 00:11:09,000 Speaker 1: has a symmetry still, but it's not like smooth. You 192 00:11:09,040 --> 00:11:12,120 Speaker 1: have to take like exactly the right size step in 193 00:11:12,200 --> 00:11:14,600 Speaker 1: order to see the universe the same way. So if 194 00:11:14,600 --> 00:11:16,960 Speaker 1: you're like inside a big crystal is a huge lattice 195 00:11:17,000 --> 00:11:19,280 Speaker 1: and you're sitting on an atom, you have to take 196 00:11:19,400 --> 00:11:21,640 Speaker 1: a step exactly the size of the lattice so that 197 00:11:21,640 --> 00:11:24,559 Speaker 1: you're still sitting on an atom. It's chess rules, except 198 00:11:24,600 --> 00:11:28,000 Speaker 1: you're all ponds. Yeah, exactly, take space and break it 199 00:11:28,080 --> 00:11:30,679 Speaker 1: up into chessboards, and you can only move one square 200 00:11:30,720 --> 00:11:32,720 Speaker 1: or two squares. You can't move one and a half 201 00:11:32,840 --> 00:11:35,160 Speaker 1: or two and a half squares. And so that's the 202 00:11:35,200 --> 00:11:37,319 Speaker 1: idea of a space crystal, and like do you think 203 00:11:37,320 --> 00:11:39,000 Speaker 1: of a crystal is a big shiny thing, But when 204 00:11:39,040 --> 00:11:41,800 Speaker 1: you zoom down into it, the reason that it's shiny, 205 00:11:41,840 --> 00:11:44,840 Speaker 1: the reason it has those properties that reflect LFE that way, 206 00:11:45,240 --> 00:11:48,600 Speaker 1: is because it has this regular structure in space. So 207 00:11:48,640 --> 00:11:51,280 Speaker 1: when we say crystal here, we generally just mean like 208 00:11:51,320 --> 00:11:55,240 Speaker 1: a regular, discrete structure. That's so interesting. I mean, crystal 209 00:11:55,360 --> 00:12:00,160 Speaker 1: structures are really interesting and evolutionary biology because they are 210 00:12:00,200 --> 00:12:05,320 Speaker 1: surprisingly sometimes used in eyeballs, like in the eyes of 211 00:12:06,000 --> 00:12:10,560 Speaker 1: mollusks will have these guanting crystal structures that help them 212 00:12:10,640 --> 00:12:14,960 Speaker 1: reflect light. You don't think of organic material as something 213 00:12:15,000 --> 00:12:17,400 Speaker 1: you can turn into a crystal, but yeah, you can 214 00:12:17,440 --> 00:12:21,439 Speaker 1: take guanting form a guanting crystal form an eyeball. That's fascinating. 215 00:12:21,600 --> 00:12:24,040 Speaker 1: So most eyeballs don't have crystals in them. It's a 216 00:12:24,080 --> 00:12:27,520 Speaker 1: special situation. Yeah, we have lenses in most eyeballs, but 217 00:12:27,640 --> 00:12:31,520 Speaker 1: those guanting crystals that form in certain eyeballs, like in 218 00:12:31,679 --> 00:12:35,480 Speaker 1: the eyes of scalps, will have this characteristic that helps 219 00:12:35,520 --> 00:12:38,319 Speaker 1: them reflect light in such a way that gives them 220 00:12:38,320 --> 00:12:43,480 Speaker 1: really interesting vision. And scallops have eyes, yes they do. 221 00:12:43,760 --> 00:12:46,800 Speaker 1: You wouldn't think so, I'll think about that. Next time 222 00:12:46,800 --> 00:12:50,720 Speaker 1: i'm biting into one, I'm tasting crystalline eyeballs. They're actually 223 00:12:50,760 --> 00:12:53,280 Speaker 1: beautiful blue eyes and they have a whole mess of them, 224 00:12:53,400 --> 00:12:56,040 Speaker 1: like two hundred of them. Oh my gosh, Well that 225 00:12:56,080 --> 00:12:58,199 Speaker 1: makes me feel better. That's why I don't eat scalops 226 00:12:58,200 --> 00:13:01,360 Speaker 1: because I don't like crystalline eyeballs. And instead of using 227 00:13:01,800 --> 00:13:05,440 Speaker 1: lenses like a human or mammal eye or most animals eyes, 228 00:13:05,480 --> 00:13:09,719 Speaker 1: they actually use mirrors inside of their eyes as kind 229 00:13:09,760 --> 00:13:14,800 Speaker 1: of a miniature telescope by using that guanting crystal structure. Wow, amazing. Well, 230 00:13:14,880 --> 00:13:17,719 Speaker 1: the other important thing to understand about these kinds of 231 00:13:17,760 --> 00:13:20,440 Speaker 1: crystals that we're talking about space crystals is that they 232 00:13:20,480 --> 00:13:23,720 Speaker 1: are stable. So like those crystals in the eyes of scallops, 233 00:13:23,840 --> 00:13:26,120 Speaker 1: or that diamond that comes up out of the ground 234 00:13:26,600 --> 00:13:29,120 Speaker 1: is stable as the regularly repeating pattern, but it doesn't 235 00:13:29,200 --> 00:13:32,080 Speaker 1: fall apart. It is in its lowest energy state, and 236 00:13:32,120 --> 00:13:34,240 Speaker 1: so we can hang out basically for a long time. 237 00:13:34,280 --> 00:13:36,480 Speaker 1: It needs to be broken up if you want those 238 00:13:36,520 --> 00:13:40,360 Speaker 1: atoms back. Is that why diamonds are so tough because 239 00:13:40,400 --> 00:13:44,400 Speaker 1: of that crystalline structure. Yeah, because the crystalline structure makes 240 00:13:44,440 --> 00:13:46,679 Speaker 1: them really hard to break. And also that's why they 241 00:13:46,760 --> 00:13:49,000 Speaker 1: last a long time because they're in a stable state. 242 00:13:49,280 --> 00:13:51,680 Speaker 1: Like the atoms, they're very happy to be in that situation. 243 00:13:51,679 --> 00:13:54,720 Speaker 1: They're not going to relax into some other lower ground 244 00:13:54,760 --> 00:13:57,960 Speaker 1: state and then break up into something else energetically. They're 245 00:13:58,080 --> 00:14:01,120 Speaker 1: very comfortable. That's so interesting. It's something like an ice 246 00:14:01,240 --> 00:14:04,520 Speaker 1: cube forms a lot of structure, but it does melt. 247 00:14:04,640 --> 00:14:09,280 Speaker 1: So is that an example of like an unstable crystal structure. Yeah. 248 00:14:09,320 --> 00:14:12,040 Speaker 1: Ice is actually super fascinating because it can form lots 249 00:14:12,080 --> 00:14:14,520 Speaker 1: of different kinds of structures. And we're gonna do a 250 00:14:14,520 --> 00:14:17,440 Speaker 1: whole podcast episode about all the different weird kinds of ice. 251 00:14:17,520 --> 00:14:20,360 Speaker 1: It's like one that's not transparent black ice, and it's 252 00:14:20,400 --> 00:14:23,480 Speaker 1: like nine other kinds of ice. So it can form 253 00:14:23,560 --> 00:14:26,120 Speaker 1: lots of weird crystal structures, but actually is in a 254 00:14:26,160 --> 00:14:28,040 Speaker 1: stable state. The only reason it melts is because you're 255 00:14:28,080 --> 00:14:31,000 Speaker 1: adding energy to it. Right. Melting means you're like heating 256 00:14:31,000 --> 00:14:33,680 Speaker 1: it up from the outside. Same with diamonds. You put 257 00:14:33,720 --> 00:14:37,360 Speaker 1: diamonds in hot enough temperatures, they will melt. That actually happens. 258 00:14:37,360 --> 00:14:39,720 Speaker 1: We think sort of like on the surface of Jupiter, 259 00:14:40,000 --> 00:14:43,440 Speaker 1: which rains diamonds into the interior, which might form like 260 00:14:43,480 --> 00:14:46,920 Speaker 1: a big liquid diamond ocean. So Jupiter is really rich, 261 00:14:47,880 --> 00:14:52,520 Speaker 1: talking about Kardashian levels of rich. Absolutely, absolutely, So now 262 00:14:52,560 --> 00:14:55,240 Speaker 1: we understand, like the idea of a crystal, it's like 263 00:14:55,280 --> 00:14:58,320 Speaker 1: a regular structure, but that's a crystal structure in space. 264 00:14:58,600 --> 00:15:00,320 Speaker 1: So now it's turned to the topic we're trying to 265 00:15:00,360 --> 00:15:03,000 Speaker 1: talk about today, which is time crystals. Right, take that 266 00:15:03,080 --> 00:15:05,960 Speaker 1: same idea and apply it to time. Okay, but how 267 00:15:06,000 --> 00:15:09,640 Speaker 1: do you put time in a crystal? Because time is 268 00:15:09,640 --> 00:15:12,800 Speaker 1: not physical matter. You can't arrange it in a lott 269 00:15:12,800 --> 00:15:15,040 Speaker 1: of structure. So what are you trying to say here? 270 00:15:15,280 --> 00:15:18,440 Speaker 1: So take the same idea you're applying to a lattice 271 00:15:18,480 --> 00:15:21,120 Speaker 1: in space, where you say, all right, the thing looks 272 00:15:21,120 --> 00:15:23,080 Speaker 1: the same if I take one step to the right, 273 00:15:23,200 --> 00:15:25,680 Speaker 1: or one step forward or one step backwards. And now 274 00:15:25,760 --> 00:15:28,800 Speaker 1: say what happens if I take a step forwards in time? 275 00:15:29,360 --> 00:15:32,359 Speaker 1: So a time crystals some kind of object or substance 276 00:15:32,680 --> 00:15:36,760 Speaker 1: which has a regular repeating pattern in time, which means 277 00:15:36,760 --> 00:15:39,360 Speaker 1: like it looks the same now and then in a second, 278 00:15:39,520 --> 00:15:41,720 Speaker 1: and then in two seconds, and then in three seconds 279 00:15:41,760 --> 00:15:43,840 Speaker 1: and in between. It doesn't have to look the same, 280 00:15:44,120 --> 00:15:48,000 Speaker 1: but it's going through some transformation so regularly returns to 281 00:15:48,040 --> 00:15:52,280 Speaker 1: the same position. So this is like four dimensional chess 282 00:15:52,560 --> 00:15:55,520 Speaker 1: where it's like you're playing this chess game where you're 283 00:15:55,520 --> 00:15:58,080 Speaker 1: only allowed to move one space at a time in 284 00:15:58,120 --> 00:16:02,360 Speaker 1: a certain direction, but it through time and not through 285 00:16:02,400 --> 00:16:06,240 Speaker 1: physical space necessarily, Yes, exactly. And so what you want 286 00:16:06,320 --> 00:16:09,560 Speaker 1: is something which returns to the same configuration, but after 287 00:16:09,760 --> 00:16:12,640 Speaker 1: discrete units of time, right, not like it's in that 288 00:16:12,680 --> 00:16:14,520 Speaker 1: same state all the time. That would just be a 289 00:16:14,560 --> 00:16:17,160 Speaker 1: space crystal. You want a time crystal which is in 290 00:16:17,160 --> 00:16:20,320 Speaker 1: a certain configuration, then moves out of it and comes back, 291 00:16:20,680 --> 00:16:22,680 Speaker 1: and then moves out of it and then comes back. 292 00:16:23,160 --> 00:16:26,160 Speaker 1: So you wanted to sort of break this continuous time 293 00:16:26,200 --> 00:16:30,200 Speaker 1: symmetry where things always look the same into a discrete symmetry, 294 00:16:30,560 --> 00:16:32,720 Speaker 1: so that it looks the same and then it doesn't, 295 00:16:32,760 --> 00:16:34,760 Speaker 1: and then it comes back and it looks the same again. 296 00:16:35,040 --> 00:16:36,960 Speaker 1: That's the property you have in a space crystal, right, 297 00:16:37,080 --> 00:16:39,680 Speaker 1: you have this distance between points in space. Now we 298 00:16:39,720 --> 00:16:43,560 Speaker 1: want distance between configurations in time. Kind of sounds like 299 00:16:43,600 --> 00:16:47,160 Speaker 1: a dance to me. You have to do your dance 300 00:16:47,240 --> 00:16:50,640 Speaker 1: movements through not just space, but through time, and it 301 00:16:50,680 --> 00:16:54,720 Speaker 1: has to synchronize in a specific way. Yes, exactly, And 302 00:16:54,760 --> 00:16:57,880 Speaker 1: the other critical thing is that it has to be stable, 303 00:16:58,080 --> 00:17:00,600 Speaker 1: meaning it has to be in its grounds eight. That 304 00:17:00,640 --> 00:17:04,200 Speaker 1: means that basically it's doing this forever. So you need 305 00:17:04,280 --> 00:17:07,879 Speaker 1: something which is both in motion but also in the 306 00:17:07,920 --> 00:17:12,840 Speaker 1: most relaxed, lowest energy state, and that's a really unusual combination. 307 00:17:12,880 --> 00:17:16,560 Speaker 1: You have to imagine something basically moving forever that sounds 308 00:17:16,600 --> 00:17:20,000 Speaker 1: like a perpetual motion, which I didn't realize is something 309 00:17:20,040 --> 00:17:23,320 Speaker 1: you could do. Well, my mind is blown, so I'm 310 00:17:23,359 --> 00:17:26,240 Speaker 1: going to try to recollect my brain back into pieces. 311 00:17:26,280 --> 00:17:28,639 Speaker 1: But before we do that, let's take a quick break. 312 00:17:41,560 --> 00:17:45,000 Speaker 1: And we're back and Daniel is trying to reassemble the 313 00:17:45,040 --> 00:17:49,280 Speaker 1: pieces of my brain that exploded. Because we were talking 314 00:17:49,320 --> 00:17:53,600 Speaker 1: about how there is something where with a time crystal 315 00:17:54,200 --> 00:17:59,280 Speaker 1: you can remain in emotion forever at a low energy state, 316 00:17:59,320 --> 00:18:02,879 Speaker 1: which sounds like perpetual motion to me, which I thought 317 00:18:03,000 --> 00:18:06,360 Speaker 1: was just science fiction. So how could this possibly happen? Yeah, 318 00:18:06,440 --> 00:18:08,879 Speaker 1: it's a really awesome question. And it's for this reason 319 00:18:08,920 --> 00:18:11,679 Speaker 1: that people thought forever like this is a silly idea. 320 00:18:11,960 --> 00:18:15,240 Speaker 1: Nobody should even talk about it. It's obviously impossible, and 321 00:18:15,280 --> 00:18:18,720 Speaker 1: it's only recently that people thought maybe there's a way 322 00:18:18,760 --> 00:18:21,400 Speaker 1: to make this happen. Maybe there's a way to configure 323 00:18:21,440 --> 00:18:25,160 Speaker 1: a system that can be in motion through time where 324 00:18:25,280 --> 00:18:28,119 Speaker 1: regularly returns to a specific state that's one of the 325 00:18:28,200 --> 00:18:31,199 Speaker 1: lattest point and yet is stable. So we could like 326 00:18:31,520 --> 00:18:35,520 Speaker 1: do this forever. And this started in about twenty twelve 327 00:18:35,920 --> 00:18:39,280 Speaker 1: when a famous physicist named Frank Wilcheck. He's at m 328 00:18:39,320 --> 00:18:41,520 Speaker 1: I T and he won the Nobel Prize for understanding 329 00:18:41,600 --> 00:18:44,439 Speaker 1: the strong interaction, which is a thing that like binds 330 00:18:44,520 --> 00:18:47,679 Speaker 1: quirks together into protons and neutrons. So he's generally a 331 00:18:47,760 --> 00:18:50,800 Speaker 1: smart guy, and he's also kind of famous for coming 332 00:18:50,800 --> 00:18:53,359 Speaker 1: out of left field with a crazy idea that turns 333 00:18:53,359 --> 00:18:55,679 Speaker 1: out to be pretty good. He's the guy, for example, 334 00:18:55,680 --> 00:18:59,000 Speaker 1: who coined the term axons to describe that hypothetical particle, 335 00:18:59,160 --> 00:19:02,359 Speaker 1: and in he put out this kind of crazy paper saying, 336 00:19:02,640 --> 00:19:05,720 Speaker 1: you know what, here's a situation where time crystals might 337 00:19:05,760 --> 00:19:10,200 Speaker 1: be possible. He constructed an example of a quantum system, 338 00:19:10,680 --> 00:19:14,160 Speaker 1: a ring of particles that sort of rotates and every 339 00:19:14,200 --> 00:19:17,840 Speaker 1: sort of clock cycle returns to a similar configuration and 340 00:19:17,880 --> 00:19:22,080 Speaker 1: repeats the same pattern in time. So exploded into like 341 00:19:22,160 --> 00:19:25,720 Speaker 1: the community of theoretical physics blowing everybody's mind. So is 342 00:19:25,800 --> 00:19:29,320 Speaker 1: this something that would happen on the quantum level. Are 343 00:19:29,400 --> 00:19:33,800 Speaker 1: we talking about entire like star systems doing this like 344 00:19:34,280 --> 00:19:36,600 Speaker 1: time crystal thing, or are we talking about something on 345 00:19:36,600 --> 00:19:39,919 Speaker 1: a very small scale. This is something a very small scale. 346 00:19:39,920 --> 00:19:42,399 Speaker 1: This would definitely be a quantum effect. It's not the 347 00:19:42,480 --> 00:19:45,320 Speaker 1: kind of thing that you can have happened from macroscopic systems. 348 00:19:45,640 --> 00:19:48,439 Speaker 1: And the reason you can only do it potentially for 349 00:19:48,600 --> 00:19:51,679 Speaker 1: quantum systems is that quantum systems have a really weird 350 00:19:51,800 --> 00:19:55,800 Speaker 1: relationship with zero energy. Right. Things that the quantum scale 351 00:19:55,840 --> 00:19:59,200 Speaker 1: can never have exactly zero energy, so when you force 352 00:19:59,280 --> 00:20:02,600 Speaker 1: them into their howest energy state, it's not actually down 353 00:20:02,640 --> 00:20:05,919 Speaker 1: to zero energy. But a whole fun podcast episode recently 354 00:20:05,920 --> 00:20:09,560 Speaker 1: about zero point energy in the Casimir effect, which basically 355 00:20:09,600 --> 00:20:12,760 Speaker 1: says if you look into empty space, it's actually filled 356 00:20:12,840 --> 00:20:16,440 Speaker 1: with an infinite number of photons because all the fields 357 00:20:16,440 --> 00:20:19,240 Speaker 1: that are out there in space can never really relax 358 00:20:19,400 --> 00:20:22,800 Speaker 1: down to zero energy. So time crystals, if you think 359 00:20:22,840 --> 00:20:27,080 Speaker 1: they're possible, could only be possible for tiny, little microscopic 360 00:20:27,119 --> 00:20:29,960 Speaker 1: quantum particles. This is like when my car battery drained 361 00:20:30,000 --> 00:20:32,879 Speaker 1: down to quote unquote zero and the mechanics that I 362 00:20:33,000 --> 00:20:35,440 Speaker 1: need a new one, But hey, guess what, I got 363 00:20:35,440 --> 00:20:38,720 Speaker 1: a little bit more out of that battery. So maybe 364 00:20:38,720 --> 00:20:42,679 Speaker 1: it was some quantum time crystals at work there. Or 365 00:20:42,680 --> 00:20:45,119 Speaker 1: when your iPhone battery says it's at zero but it's 366 00:20:45,160 --> 00:20:48,080 Speaker 1: still running, and you're like, am I using the Casimir 367 00:20:48,080 --> 00:20:51,320 Speaker 1: effect to charge my bode? And you might also be imagining, 368 00:20:51,600 --> 00:20:54,919 Speaker 1: you know, obvious examples of like larger physical systems, not 369 00:20:55,040 --> 00:20:57,600 Speaker 1: just stars, that seem to have this property that they 370 00:20:57,600 --> 00:21:00,359 Speaker 1: could spin, for example, and return to the same state. 371 00:21:00,440 --> 00:21:03,040 Speaker 1: Like think about a wheel with spokes. As it rotates, 372 00:21:03,040 --> 00:21:06,240 Speaker 1: it returns to basically the same configuration. The problem is 373 00:21:06,280 --> 00:21:10,480 Speaker 1: that bicycle wheels, a macroscopic object, could never actually spin forever. 374 00:21:11,000 --> 00:21:13,320 Speaker 1: And that's also not its ground state. It's not the 375 00:21:13,480 --> 00:21:17,080 Speaker 1: most lowest energy state. Lowest energy state for a bicycle 376 00:21:17,080 --> 00:21:19,840 Speaker 1: wheel is when it's stopped right, And so that's why 377 00:21:19,920 --> 00:21:23,600 Speaker 1: we aren't able to actually make a perpetual motion machine 378 00:21:23,840 --> 00:21:26,760 Speaker 1: out of bicycle wheels and water and marbles and so 379 00:21:26,800 --> 00:21:28,760 Speaker 1: on and so forth. But Frank will Check wrote this 380 00:21:28,800 --> 00:21:30,720 Speaker 1: paper and said, you know what, it might be possible 381 00:21:30,720 --> 00:21:33,840 Speaker 1: for quantum objects, basically like a little quantum wheel. He 382 00:21:34,000 --> 00:21:37,160 Speaker 1: tried to show this thing could spin forever and actually 383 00:21:37,160 --> 00:21:40,000 Speaker 1: be in its ground state. Now. Of course this set 384 00:21:40,040 --> 00:21:43,240 Speaker 1: off like a lot of conversations in the theoretical physics community. 385 00:21:43,520 --> 00:21:46,520 Speaker 1: And there's another theorist, Patrick Bruno, who actually found a 386 00:21:46,600 --> 00:21:51,080 Speaker 1: mistake in well checked paper tattletale. I know this, but 387 00:21:51,160 --> 00:21:54,560 Speaker 1: this is a good lesson, like Nobel Prize winners make mistakes. 388 00:21:54,680 --> 00:21:56,800 Speaker 1: I feel like a lot of times people quote Nobel 389 00:21:56,800 --> 00:21:58,879 Speaker 1: Prize winners and if they said it and they want 390 00:21:58,920 --> 00:22:01,840 Speaker 1: a Nobel Prize in must be the truth, right, But 391 00:22:02,000 --> 00:22:04,560 Speaker 1: like they're just people. You know, Yes, they're smart and 392 00:22:04,600 --> 00:22:07,760 Speaker 1: they got lucky, but they're also people and sometimes they 393 00:22:07,800 --> 00:22:11,919 Speaker 1: make mistakes. Ye take that, you Nobel Prize winning smarty pants. 394 00:22:13,560 --> 00:22:16,240 Speaker 1: I especially love it when they interview a Nobel Prize 395 00:22:16,280 --> 00:22:18,760 Speaker 1: winner on a topic they're like, not an expert in 396 00:22:19,040 --> 00:22:21,600 Speaker 1: you know, you'll hear like a Nobel Prize winning physicist 397 00:22:21,840 --> 00:22:24,560 Speaker 1: commenting on economic policy and you're like, you don't know 398 00:22:24,600 --> 00:22:27,200 Speaker 1: anything more about that than anybody else, Like just because 399 00:22:27,200 --> 00:22:31,480 Speaker 1: he won the Nobel Prize, Yeah, you know, I'm as 400 00:22:31,560 --> 00:22:34,119 Speaker 1: much a Nobel Prize winner in a field you didn't 401 00:22:34,160 --> 00:22:38,160 Speaker 1: study as you are Nobel Prize winner in physics. So they're, yeah, 402 00:22:38,200 --> 00:22:42,160 Speaker 1: exactly what was this mistake and how did that change 403 00:22:42,280 --> 00:22:44,600 Speaker 1: this whole concept of being able to have these little, 404 00:22:45,119 --> 00:22:48,480 Speaker 1: little tiny time crystals. Yeah. So Patrick Bruno showed that 405 00:22:48,520 --> 00:22:52,199 Speaker 1: the example that will Check proposed, this idea of a 406 00:22:52,359 --> 00:22:55,760 Speaker 1: ring of particles rotating was actually more similar to a 407 00:22:55,840 --> 00:22:58,400 Speaker 1: bicycle wheel spinning than we thought that he would only 408 00:22:58,520 --> 00:23:01,200 Speaker 1: rotate if it was actually in a more energetic state, 409 00:23:01,440 --> 00:23:04,080 Speaker 1: and he showed that the example that will Check suggested 410 00:23:04,440 --> 00:23:07,520 Speaker 1: had the possibility to decay into a ground state which 411 00:23:07,560 --> 00:23:10,600 Speaker 1: wouldn't be rotating, and so it wouldn't actually qualify as 412 00:23:10,600 --> 00:23:13,159 Speaker 1: a time crystal. But you know, once the idea is 413 00:23:13,200 --> 00:23:16,400 Speaker 1: out there, then people started working on They thought, that's interesting, 414 00:23:16,800 --> 00:23:19,400 Speaker 1: let's reinvestigate a lot of times you have an area 415 00:23:19,440 --> 00:23:21,520 Speaker 1: in physics where people are like, oh, we already know 416 00:23:21,560 --> 00:23:24,320 Speaker 1: the answer there, that's totally impossible, and it takes one 417 00:23:24,400 --> 00:23:28,159 Speaker 1: brave person like dig into again and ask the question anew, 418 00:23:28,560 --> 00:23:30,239 Speaker 1: and then a lot of people will follow and be like, oh, 419 00:23:30,280 --> 00:23:33,080 Speaker 1: that's interesting, I wonder if we could actually crack this problem. 420 00:23:33,280 --> 00:23:35,639 Speaker 1: And so Frank will Checks credit with like cracking this 421 00:23:35,720 --> 00:23:38,080 Speaker 1: problem open again, and then a huge number of people 422 00:23:38,119 --> 00:23:40,200 Speaker 1: started writing papers, and there were a lot of people 423 00:23:40,240 --> 00:23:42,520 Speaker 1: that said, oh no, it turns out of time crystals 424 00:23:42,560 --> 00:23:45,720 Speaker 1: completely impossible. They wrote all these no go papers that 425 00:23:45,840 --> 00:23:48,959 Speaker 1: proved under various conditions. You could never have a time crystal. 426 00:23:49,000 --> 00:23:52,119 Speaker 1: You can never have a quantum mechanical arrangement of particles 427 00:23:52,160 --> 00:23:55,399 Speaker 1: that repeats in time and is at its ground state. 428 00:23:55,680 --> 00:23:58,520 Speaker 1: Wet blankets trying to make it so that I can't 429 00:23:58,520 --> 00:24:02,760 Speaker 1: make a little quantum circus with a little merry go round, 430 00:24:02,960 --> 00:24:06,080 Speaker 1: and I'm thinking about cork on a unicycle just going 431 00:24:06,200 --> 00:24:07,919 Speaker 1: on forever, and I don't like it. I want to 432 00:24:07,920 --> 00:24:11,840 Speaker 1: hear some optimism. Well, we'll talk about the actual experiments 433 00:24:11,880 --> 00:24:13,960 Speaker 1: in a minute, because this also inspired a bunch of 434 00:24:13,960 --> 00:24:16,120 Speaker 1: folks to say, well, let's go see if we can 435 00:24:16,160 --> 00:24:19,360 Speaker 1: make one. You know, sometimes the theorists say that's as possible, 436 00:24:19,400 --> 00:24:22,119 Speaker 1: this is impossible, but it's up to the universe to 437 00:24:22,200 --> 00:24:25,480 Speaker 1: decide whether it actually happens. And so I like when 438 00:24:25,480 --> 00:24:28,080 Speaker 1: experimentalists sort of don't listen to the theorists and just 439 00:24:28,119 --> 00:24:32,240 Speaker 1: go out there and explore. But it's actually really interesting 440 00:24:32,280 --> 00:24:35,000 Speaker 1: and important question about time crystals because it gets to 441 00:24:35,040 --> 00:24:37,639 Speaker 1: the heart of how we think about time. And this 442 00:24:37,720 --> 00:24:40,080 Speaker 1: is something you were bringing up earlier, like is time 443 00:24:40,119 --> 00:24:43,200 Speaker 1: or real thing? If time crystals are really really would 444 00:24:43,200 --> 00:24:46,199 Speaker 1: tell us something fundamental about the nature of like time 445 00:24:46,280 --> 00:24:49,560 Speaker 1: and the universe. Yeah, because I feel like we don't 446 00:24:49,600 --> 00:24:53,399 Speaker 1: really have a frame of reference outside of our human 447 00:24:53,480 --> 00:24:57,080 Speaker 1: invention of We mark the minutes, we mark the seconds. 448 00:24:57,160 --> 00:25:01,000 Speaker 1: We pick sort of these units of time, probably based 449 00:25:01,040 --> 00:25:03,719 Speaker 1: on our ability to like the time it takes us 450 00:25:03,760 --> 00:25:06,359 Speaker 1: to think about a second, is about how long a 451 00:25:06,400 --> 00:25:09,880 Speaker 1: second is, So you know, it's based very much on 452 00:25:09,960 --> 00:25:13,480 Speaker 1: our human brains. But it's interesting. I guess I've never 453 00:25:13,480 --> 00:25:17,280 Speaker 1: really thought too much about finding empirical evidence for their 454 00:25:17,320 --> 00:25:20,119 Speaker 1: being time. Well, it's also really interesting to sort of 455 00:25:20,160 --> 00:25:24,160 Speaker 1: dig into it theoretically and ask, like our fundamental picture 456 00:25:24,400 --> 00:25:27,439 Speaker 1: of the universe, what does that tell us about time? 457 00:25:28,000 --> 00:25:30,520 Speaker 1: And we have two pictures of the universe the way 458 00:25:30,600 --> 00:25:33,480 Speaker 1: things work sort of at the deepest level in the universe, 459 00:25:33,720 --> 00:25:38,280 Speaker 1: quantum mechanics and general relativity. And as listeners the podcast know, 460 00:25:38,440 --> 00:25:41,560 Speaker 1: these two don't often agree, and that's also the case 461 00:25:41,720 --> 00:25:45,200 Speaker 1: about the nature of time. Have very different opinions about 462 00:25:45,280 --> 00:25:49,960 Speaker 1: what time is, and quantum mechanics says that space and 463 00:25:50,000 --> 00:25:53,080 Speaker 1: time are very different, and according to quantum mechanics, you 464 00:25:53,119 --> 00:25:55,399 Speaker 1: have like a description of the universe. It says like, 465 00:25:55,640 --> 00:25:58,679 Speaker 1: here's your quantum particle, there's your quantum particle, whatever. And 466 00:25:58,720 --> 00:26:01,480 Speaker 1: you know, quantum mechanics tells us what's likely to happen 467 00:26:01,520 --> 00:26:04,320 Speaker 1: to those particles in the future, and all that crazy 468 00:26:04,359 --> 00:26:07,000 Speaker 1: stuff that we can dig into another episode. But the 469 00:26:07,040 --> 00:26:10,240 Speaker 1: important thing is that quantum mechanics tells us how those 470 00:26:10,320 --> 00:26:14,080 Speaker 1: quantum states evolved, like the Shortinger equation, the most famous equation, 471 00:26:14,200 --> 00:26:16,679 Speaker 1: and quantum mechanics, that's what it does. It tells us, 472 00:26:17,000 --> 00:26:18,840 Speaker 1: if you have a quantum state, here's what it's going 473 00:26:18,880 --> 00:26:21,680 Speaker 1: to look like in the future. And also you can 474 00:26:21,680 --> 00:26:24,520 Speaker 1: turn that equation around and you can say, here's how 475 00:26:24,560 --> 00:26:27,000 Speaker 1: you got to now, here's how the past must have 476 00:26:27,040 --> 00:26:30,080 Speaker 1: looked if the present looks this way. And there's a 477 00:26:30,119 --> 00:26:33,720 Speaker 1: concept we often talk about called quantum information, and that's 478 00:26:33,720 --> 00:26:35,960 Speaker 1: what this means. It says that if you know how 479 00:26:36,000 --> 00:26:38,600 Speaker 1: the universe looks now, you can figure out how we 480 00:26:38,760 --> 00:26:42,720 Speaker 1: got here because quantum information is never destroyed. And that's 481 00:26:42,720 --> 00:26:44,800 Speaker 1: a deep and fundamental statement about the nature of the 482 00:26:44,880 --> 00:26:48,560 Speaker 1: universe because it means, according to quantum mechanics, the time 483 00:26:48,720 --> 00:26:51,840 Speaker 1: is eternal time like goes on forever into the future 484 00:26:52,200 --> 00:26:56,439 Speaker 1: and into the past. So that's true of quantum mechanics, 485 00:26:56,440 --> 00:26:59,679 Speaker 1: like in the quantum miniature universe, but like when we 486 00:27:00,000 --> 00:27:03,400 Speaker 1: look at the larger universe, once we scale it up, 487 00:27:03,480 --> 00:27:06,520 Speaker 1: those ideas don't hold true. Yeah, exactly. This is relevant 488 00:27:06,560 --> 00:27:09,080 Speaker 1: to the rules of tiny little particles. But you're right, 489 00:27:09,080 --> 00:27:11,040 Speaker 1: when we scale up to the rest of the universe, 490 00:27:11,080 --> 00:27:13,440 Speaker 1: things do look a little different. And this is when 491 00:27:13,560 --> 00:27:16,520 Speaker 1: general relativity comes in, because when it comes to like 492 00:27:16,720 --> 00:27:19,480 Speaker 1: the shape of the universe and the age of the universe, 493 00:27:19,680 --> 00:27:23,280 Speaker 1: the thing that matters most is gravity, and general relativity 494 00:27:23,359 --> 00:27:26,480 Speaker 1: is the best theory we have that describes how gravity works. 495 00:27:26,800 --> 00:27:30,000 Speaker 1: And the most important concept in general relativity that's relevant 496 00:27:30,040 --> 00:27:33,440 Speaker 1: for today's conversation is this notion that space and time 497 00:27:33,480 --> 00:27:36,960 Speaker 1: are very deeply connected, or quantum mechanics says space time 498 00:27:37,000 --> 00:27:40,359 Speaker 1: are separate. Time is just like the way that things 499 00:27:40,440 --> 00:27:44,600 Speaker 1: in space evolve one step to the other. General relativity says, no, no, no, 500 00:27:45,000 --> 00:27:47,800 Speaker 1: Time is like just one part of this thing we 501 00:27:47,880 --> 00:27:51,560 Speaker 1: call space time, and there's a deep symmetry between space 502 00:27:51,600 --> 00:27:54,080 Speaker 1: and time, and they evolve together and they get twisted 503 00:27:54,119 --> 00:27:57,440 Speaker 1: together and they really closely connected. And if you think 504 00:27:57,440 --> 00:28:00,119 Speaker 1: about what general relativity says about time even more deeply, 505 00:28:00,520 --> 00:28:03,760 Speaker 1: you know, general relativity says that the universe is expanding 506 00:28:04,000 --> 00:28:06,040 Speaker 1: and that it used to be denser, and as you 507 00:28:06,080 --> 00:28:08,679 Speaker 1: look backwards in time, time doesn't go on forever. It 508 00:28:08,760 --> 00:28:11,320 Speaker 1: comes back to some sort of like singularity in the 509 00:28:11,400 --> 00:28:14,600 Speaker 1: early universe. And according to general relativity, is very natural, 510 00:28:14,640 --> 00:28:17,480 Speaker 1: for example, to have a beginning of time, for time 511 00:28:17,480 --> 00:28:21,359 Speaker 1: to have started rum zero in the early universe. So 512 00:28:21,480 --> 00:28:24,560 Speaker 1: quantum mechanics says space and time very different and time 513 00:28:24,640 --> 00:28:28,160 Speaker 1: has lasted forever. General relativity says, no, no no, no, These 514 00:28:28,200 --> 00:28:30,520 Speaker 1: are just two different sides of the same coin. And 515 00:28:30,560 --> 00:28:32,720 Speaker 1: it makes perfect sense for time to have started in 516 00:28:32,720 --> 00:28:35,679 Speaker 1: the early universe. So two very different pictures about this 517 00:28:35,800 --> 00:28:38,959 Speaker 1: very basic piece of the universe. Well, the universe is 518 00:28:39,040 --> 00:28:43,080 Speaker 1: made out of quantum particles, and so the bigger aspects 519 00:28:43,080 --> 00:28:46,600 Speaker 1: of the universe are made up of the quantum aspects 520 00:28:46,600 --> 00:28:49,239 Speaker 1: of the universe. So it's very interesting that you have 521 00:28:49,400 --> 00:28:54,719 Speaker 1: this disagreement ostensibly between basically the some of the parts 522 00:28:54,760 --> 00:28:58,160 Speaker 1: and the parts themselves. Yeah, you're absolutely right, And one 523 00:28:58,240 --> 00:29:00,840 Speaker 1: of the reasons they disagree is that usually they play 524 00:29:00,840 --> 00:29:04,560 Speaker 1: in different fields. When we talk about tiny little particles, 525 00:29:04,600 --> 00:29:07,320 Speaker 1: gravity is so weak that it's basically irrelevant, and we 526 00:29:07,360 --> 00:29:10,120 Speaker 1: can ignore what general relativity says. And then when we 527 00:29:10,200 --> 00:29:13,080 Speaker 1: zoom up to talk about stars and planets, all those 528 00:29:13,120 --> 00:29:15,920 Speaker 1: tiny little particles are so small they get just averaged out. 529 00:29:15,920 --> 00:29:19,360 Speaker 1: All the quantum effects basically disappear. So general relativity is 530 00:29:19,440 --> 00:29:22,960 Speaker 1: dominant for really big heavy stuff, and quantum mechanics are 531 00:29:23,040 --> 00:29:26,440 Speaker 1: dominant for really tiny, very low mass stuff. And it's 532 00:29:26,560 --> 00:29:29,239 Speaker 1: very rare for the two to be important, so we 533 00:29:29,280 --> 00:29:32,479 Speaker 1: can't tell like who wins when they're both important. The 534 00:29:32,480 --> 00:29:34,000 Speaker 1: only way to figure that out is to do things 535 00:29:34,080 --> 00:29:36,920 Speaker 1: like look inside of a black hole, where things are 536 00:29:36,920 --> 00:29:40,800 Speaker 1: so small but so dense that both of them are important. 537 00:29:41,000 --> 00:29:42,800 Speaker 1: And that's not something we've been able to do yet, 538 00:29:44,000 --> 00:29:46,840 Speaker 1: not yet. Maybe in a few years. Well, I want 539 00:29:46,840 --> 00:29:50,560 Speaker 1: to hear about how this disagreement impacts whether or not 540 00:29:50,640 --> 00:29:55,080 Speaker 1: I can have my tiny time crystal Carnival. But maybe 541 00:29:55,120 --> 00:29:57,440 Speaker 1: we should take a quick break first of while I 542 00:29:57,560 --> 00:30:14,840 Speaker 1: draw up some little quantum merrigo rounds schematics. We are back. 543 00:30:14,960 --> 00:30:18,920 Speaker 1: I'm trying to decide whether to sell cotton candy at 544 00:30:18,960 --> 00:30:22,640 Speaker 1: my little quantum Carnival with the time crystal Dance, the 545 00:30:22,760 --> 00:30:27,080 Speaker 1: time crystal Carousel, And so Daniel is going to explain 546 00:30:27,160 --> 00:30:33,760 Speaker 1: to me how quantum mechanics and general relativity, the small 547 00:30:33,920 --> 00:30:36,440 Speaker 1: side of the universe, the quantum side, and the big side, 548 00:30:36,520 --> 00:30:39,920 Speaker 1: the US and stars and everything else can disagree so 549 00:30:40,000 --> 00:30:43,440 Speaker 1: much about time and space. Yeah, well, I wish we 550 00:30:43,520 --> 00:30:45,680 Speaker 1: knew the answer to that. But one way that we 551 00:30:45,800 --> 00:30:48,360 Speaker 1: might be able to probe it is to look inside 552 00:30:48,400 --> 00:30:51,120 Speaker 1: the core of a black hole and understand, you know, 553 00:30:51,200 --> 00:30:53,719 Speaker 1: who's right about the nature of the universe, or go 554 00:30:53,800 --> 00:30:55,880 Speaker 1: back in time to the Big Bang. But you know 555 00:30:55,960 --> 00:30:59,440 Speaker 1: that's kind of inaccessible. So we're excited anytime we can 556 00:30:59,520 --> 00:31:02,280 Speaker 1: probe thing that we think gets near this question that 557 00:31:02,360 --> 00:31:05,840 Speaker 1: lets us like understand around the edges of these questions 558 00:31:05,880 --> 00:31:08,800 Speaker 1: about the fundamental nature of the universe. And that's why 559 00:31:08,880 --> 00:31:12,960 Speaker 1: time crystals are super fascinating because they explore this connection 560 00:31:13,280 --> 00:31:17,760 Speaker 1: between space and time. Like if time crystals can actually 561 00:31:17,840 --> 00:31:21,000 Speaker 1: be made, it's really a strong argument that there's a 562 00:31:21,000 --> 00:31:24,000 Speaker 1: close connection between space and time, that this thing that 563 00:31:24,080 --> 00:31:27,600 Speaker 1: exists in space space crystals can also be made in time, 564 00:31:27,640 --> 00:31:29,960 Speaker 1: that time can be seen sort of like as another 565 00:31:30,120 --> 00:31:33,680 Speaker 1: dimension of space. It adds sort of like a check 566 00:31:33,680 --> 00:31:36,560 Speaker 1: in the column of general relativity. And so that would 567 00:31:36,600 --> 00:31:41,240 Speaker 1: mean that quantum mechanics is actually behaving in a way 568 00:31:41,400 --> 00:31:45,800 Speaker 1: that is following the rules of general relativity. It would 569 00:31:45,840 --> 00:31:48,880 Speaker 1: mean that we need to adapt somehow quantum mechanics to 570 00:31:48,960 --> 00:31:51,400 Speaker 1: play along nicely with this concept that space and time 571 00:31:51,440 --> 00:31:55,040 Speaker 1: are deeply connected. And you know, we know already that 572 00:31:55,120 --> 00:31:58,680 Speaker 1: quantum mechanics can't really be right about time being eternal 573 00:31:58,720 --> 00:32:02,080 Speaker 1: in every direction, like we think the universe had a beginning, 574 00:32:02,360 --> 00:32:04,640 Speaker 1: So it doesn't really make sense to hold tightly to 575 00:32:04,720 --> 00:32:07,920 Speaker 1: this concept that time must be eternal. On the other hand, 576 00:32:08,280 --> 00:32:10,280 Speaker 1: it's a pretty big thing to get rid of, to 577 00:32:10,360 --> 00:32:14,320 Speaker 1: let go of this concept of quantum unitarity, that quantum 578 00:32:14,360 --> 00:32:18,040 Speaker 1: information is not ever lost. That's something we really think 579 00:32:18,120 --> 00:32:20,560 Speaker 1: is that the foundation of quantum mechanics. So one of 580 00:32:20,600 --> 00:32:23,640 Speaker 1: these theories has to get torn up basically and start again. 581 00:32:23,960 --> 00:32:26,800 Speaker 1: And the question is which. And we're hoping that time 582 00:32:26,840 --> 00:32:29,960 Speaker 1: crystals give us like a glimmer of understanding as to 583 00:32:30,000 --> 00:32:32,760 Speaker 1: how to begin that process. But even if we knew 584 00:32:33,000 --> 00:32:35,960 Speaker 1: right for example, that general relativity was correct, doesn't tell 585 00:32:36,000 --> 00:32:39,280 Speaker 1: us exactly how to start on quantum mechanics, and before 586 00:32:39,280 --> 00:32:42,280 Speaker 1: we put too many nails in the coffin of quantum mechanics, like, 587 00:32:42,520 --> 00:32:45,520 Speaker 1: I don't think anybody out there in physics believes general 588 00:32:45,520 --> 00:32:48,680 Speaker 1: relativity is correct. It's got to be wrong because it 589 00:32:48,760 --> 00:32:52,480 Speaker 1: assumes that the universe is smooth and continuous in a 590 00:32:52,520 --> 00:32:55,840 Speaker 1: way that quantum mechanics we know our experiments tell us 591 00:32:55,920 --> 00:32:59,080 Speaker 1: just can't be true. So my money is on both 592 00:32:59,120 --> 00:33:00,760 Speaker 1: of them are wrong. And we kind of come up 593 00:33:00,800 --> 00:33:03,120 Speaker 1: with a whole new theory that combines the two or 594 00:33:03,280 --> 00:33:06,760 Speaker 1: kind of cross checking these two rule books that were 595 00:33:06,760 --> 00:33:11,080 Speaker 1: writing based on the quantum information and then the larger 596 00:33:11,120 --> 00:33:15,960 Speaker 1: scale general relativity information. And it sounds like you physicists 597 00:33:16,000 --> 00:33:19,720 Speaker 1: have to cross check them and figure out where which 598 00:33:19,800 --> 00:33:22,320 Speaker 1: things make sense and then kind of get rid of 599 00:33:22,320 --> 00:33:24,240 Speaker 1: the things that don't as you cross check them, and 600 00:33:24,520 --> 00:33:27,280 Speaker 1: time crystals might help you do that. Yeah, exactly, And 601 00:33:27,320 --> 00:33:30,160 Speaker 1: you're right, we're sort of trying to weave these threads together. 602 00:33:30,200 --> 00:33:31,920 Speaker 1: You know, people have been working on quantum mechanics for 603 00:33:31,960 --> 00:33:33,920 Speaker 1: a while, people have been working on job relativity for 604 00:33:33,960 --> 00:33:36,080 Speaker 1: a while, and the goal, of course, is to come 605 00:33:36,120 --> 00:33:39,400 Speaker 1: up with a single holistic explanation from the whole universe 606 00:33:39,440 --> 00:33:42,640 Speaker 1: or how everything fits together, and that requires like trying 607 00:33:42,640 --> 00:33:45,760 Speaker 1: to weave these threats together. And in the past we've succeeded, 608 00:33:45,760 --> 00:33:48,760 Speaker 1: Like we figured out that electricity and magnetism are really 609 00:33:48,800 --> 00:33:51,400 Speaker 1: just two sides of the same coin, and neither theory 610 00:33:51,560 --> 00:33:53,360 Speaker 1: was wrong. They just sort of fit together in an 611 00:33:53,400 --> 00:33:56,080 Speaker 1: unexpected way. And then we added the weak force, and 612 00:33:56,080 --> 00:33:59,480 Speaker 1: now we have like a theory of the electromagnetic weak forces. 613 00:33:59,520 --> 00:34:03,000 Speaker 1: These three things sort of woven together into one common understanding. 614 00:34:03,240 --> 00:34:05,840 Speaker 1: The goal is to make progress by pulling these things together, 615 00:34:06,120 --> 00:34:08,920 Speaker 1: by getting our understanding from various bits of physics and 616 00:34:08,960 --> 00:34:11,520 Speaker 1: sort of putting it together to make a holistic picture. 617 00:34:11,760 --> 00:34:14,080 Speaker 1: And there's one more part of that thread that we 618 00:34:14,160 --> 00:34:17,040 Speaker 1: might try to pull in, and this this idea about 619 00:34:17,040 --> 00:34:21,240 Speaker 1: the connection between time and energy. Right the time crystal, 620 00:34:21,320 --> 00:34:24,160 Speaker 1: if it exists, is a weird thing because it's in motion, 621 00:34:24,200 --> 00:34:27,040 Speaker 1: but it's also like at its lowest energy state. Well, 622 00:34:27,040 --> 00:34:31,080 Speaker 1: there's another deep theorem about physics, Nother's theorem that tells 623 00:34:31,200 --> 00:34:35,080 Speaker 1: us why we have energy conservation in our universe. It 624 00:34:35,160 --> 00:34:38,479 Speaker 1: says that energy is conserved in our universe because there's 625 00:34:38,520 --> 00:34:41,439 Speaker 1: some symmetry with time that the laws of physics should 626 00:34:41,480 --> 00:34:44,320 Speaker 1: work the same now as they do in ten seconds 627 00:34:44,400 --> 00:34:46,719 Speaker 1: or in a million years. And we've talked in the 628 00:34:46,719 --> 00:34:49,680 Speaker 1: program before how we're not actually sure whether energy is 629 00:34:49,680 --> 00:34:52,799 Speaker 1: conserved because the universe is not actually static in time. 630 00:34:52,840 --> 00:34:56,160 Speaker 1: It's growing with time, it's expanding. So all these questions 631 00:34:56,200 --> 00:34:58,520 Speaker 1: are all mixed up in the very nature of time 632 00:34:58,800 --> 00:35:01,080 Speaker 1: and the meaning of it, and the conservation of energy 633 00:35:01,160 --> 00:35:03,920 Speaker 1: and general relativity versus quantum mechanics, which is why I 634 00:35:03,960 --> 00:35:08,319 Speaker 1: was so excited to see experimental tests of time crystals, Like, 635 00:35:08,600 --> 00:35:11,800 Speaker 1: all right, put the theoretical questions aside, can somebody actually 636 00:35:11,800 --> 00:35:14,160 Speaker 1: make one of these things? Right? How do you? I mean, 637 00:35:14,200 --> 00:35:17,239 Speaker 1: it seems like you need really tiny pliers and a 638 00:35:17,320 --> 00:35:21,840 Speaker 1: really powerful microscope to be able to make a time crystal. 639 00:35:22,000 --> 00:35:25,080 Speaker 1: How do you go about doing those experiments? So the 640 00:35:25,120 --> 00:35:28,080 Speaker 1: original idea of this ring of atoms didn't work because 641 00:35:28,080 --> 00:35:30,840 Speaker 1: people showed that it was not actually in its ground state. 642 00:35:31,160 --> 00:35:33,120 Speaker 1: But then a bunch of smart people got together and 643 00:35:33,160 --> 00:35:36,160 Speaker 1: came up with, you know, other ideas, and you're exactly right, 644 00:35:36,160 --> 00:35:39,560 Speaker 1: you need really tiny pliers. And usually in physics, when 645 00:35:39,560 --> 00:35:42,640 Speaker 1: we're talking about tiny players were talking about photons, we're 646 00:35:42,680 --> 00:35:45,719 Speaker 1: talking about like shooting little beams of light at individual 647 00:35:45,760 --> 00:35:48,719 Speaker 1: atoms to try to make them do something interesting. And 648 00:35:48,719 --> 00:35:51,160 Speaker 1: so that's exactly what they did here. They put a 649 00:35:51,160 --> 00:35:55,160 Speaker 1: bunch of atoms together and then they zapped them with lasers. 650 00:35:55,239 --> 00:35:58,399 Speaker 1: And atoms, you know, have various ways that they can sit. 651 00:35:58,840 --> 00:36:02,120 Speaker 1: These atoms, for example, have a particular quantum spin. They 652 00:36:02,160 --> 00:36:04,920 Speaker 1: can spin up or they can spin down. And remember 653 00:36:04,920 --> 00:36:07,400 Speaker 1: we're not talking about atoms spinning the way like a 654 00:36:07,440 --> 00:36:09,920 Speaker 1: basketball spins on the tip of your finger. This is 655 00:36:09,960 --> 00:36:13,200 Speaker 1: some weird quantum mechanical property. And so it either has 656 00:36:13,239 --> 00:36:16,080 Speaker 1: spin up or it has spin down. It's very difficult 657 00:36:16,120 --> 00:36:18,480 Speaker 1: for it to be sort of in between. So you 658 00:36:18,719 --> 00:36:21,440 Speaker 1: arrange a bunch of these atoms in a row, and 659 00:36:21,480 --> 00:36:23,600 Speaker 1: then the atoms like to either be spin up or 660 00:36:23,680 --> 00:36:26,040 Speaker 1: spin down, and then you zap them with a laser, 661 00:36:26,160 --> 00:36:30,200 Speaker 1: which makes those spins flip. I see, so you're zapping them, 662 00:36:30,239 --> 00:36:33,640 Speaker 1: they have a certain spin preference, and then they start 663 00:36:33,760 --> 00:36:36,480 Speaker 1: to go the other direction. Yeah, So you have them 664 00:36:36,480 --> 00:36:39,120 Speaker 1: in some arrangement like the spin up, spin up, spin down, 665 00:36:39,160 --> 00:36:41,800 Speaker 1: spin up, whatever, and then you zap them with a laser. 666 00:36:41,920 --> 00:36:45,279 Speaker 1: And the laser is basically just photons, right, This is 667 00:36:45,280 --> 00:36:48,600 Speaker 1: an oscillating electromagnetic field, and so it can flip the 668 00:36:48,640 --> 00:36:52,239 Speaker 1: spins because these atoms all have electric charges. So the 669 00:36:52,320 --> 00:36:54,640 Speaker 1: laser comes in and it can flip the spins in 670 00:36:54,640 --> 00:36:57,800 Speaker 1: a certain pattern. Because the laser is an electromagnetic field 671 00:36:57,800 --> 00:37:00,480 Speaker 1: that cannot oscillate up and flip spins up and then 672 00:37:00,480 --> 00:37:03,799 Speaker 1: as laid down and flip spins down. So what we see, 673 00:37:03,880 --> 00:37:07,000 Speaker 1: this is super interesting in these experiments, is that they 674 00:37:07,080 --> 00:37:09,960 Speaker 1: arrange these atoms in a random pattern. The laser comes 675 00:37:10,000 --> 00:37:13,000 Speaker 1: in and it makes these spins flip. They oscillate, right, 676 00:37:13,280 --> 00:37:15,120 Speaker 1: you might think, all right, well, that's no big deal, 677 00:37:15,239 --> 00:37:17,840 Speaker 1: but you're slapping them around exactly, you're slapping them around. 678 00:37:18,120 --> 00:37:20,760 Speaker 1: But then what happens when you turn off the laser. 679 00:37:21,160 --> 00:37:24,360 Speaker 1: You turn off the laser and these atoms keep flipping. 680 00:37:24,960 --> 00:37:28,120 Speaker 1: You keep flipping in exactly the same pattern as when 681 00:37:28,120 --> 00:37:32,040 Speaker 1: you had the laser on. So they remember how they're 682 00:37:32,040 --> 00:37:36,080 Speaker 1: supposed to flip, even after the laser that's been smacking 683 00:37:36,120 --> 00:37:39,720 Speaker 1: them around stops doing that. Exactly, they're in some weird 684 00:37:40,120 --> 00:37:44,120 Speaker 1: stable configuration where they're in motion and they're returning to 685 00:37:44,160 --> 00:37:46,960 Speaker 1: the same state over and over again, and they're not 686 00:37:47,000 --> 00:37:49,960 Speaker 1: just static, right, they're in motion. This is some ground 687 00:37:50,040 --> 00:37:54,400 Speaker 1: state configuration that's above zero, so it has continuous energy. 688 00:37:54,640 --> 00:37:57,640 Speaker 1: So how long do they do this? Because you know, 689 00:37:57,840 --> 00:38:01,520 Speaker 1: someone might think of like that Newton's Cradle office toy 690 00:38:01,640 --> 00:38:04,000 Speaker 1: where you started going and it goes for a while 691 00:38:04,040 --> 00:38:07,000 Speaker 1: even without you doing the initial thing, but with the 692 00:38:07,040 --> 00:38:10,320 Speaker 1: conservation of momentum and eventually breaks down and stops moving. 693 00:38:10,640 --> 00:38:14,200 Speaker 1: So what happens with these atoms? Yeah, that's a great question, 694 00:38:14,440 --> 00:38:16,920 Speaker 1: and this is an experimental issue, right. In order to 695 00:38:16,960 --> 00:38:18,960 Speaker 1: do this, you need to like isolate these atoms, so 696 00:38:19,000 --> 00:38:20,960 Speaker 1: you need to put them in some sort of larger trap, 697 00:38:21,040 --> 00:38:23,279 Speaker 1: like use magnets or something to keep the rest of 698 00:38:23,320 --> 00:38:25,480 Speaker 1: the world from like messing it up. If you were 699 00:38:25,480 --> 00:38:28,239 Speaker 1: in an empty universe where it's just these atoms and 700 00:38:28,280 --> 00:38:31,200 Speaker 1: a laser, then we think it could last essentially forever 701 00:38:31,360 --> 00:38:34,360 Speaker 1: if it really is a time crystal. But it's difficult 702 00:38:34,360 --> 00:38:37,200 Speaker 1: to keep these things sort of isolated forever. People can 703 00:38:37,239 --> 00:38:39,440 Speaker 1: do it for minutes at a time, but that's the 704 00:38:39,480 --> 00:38:42,360 Speaker 1: longest that's been achieved. But we think that's just because 705 00:38:42,360 --> 00:38:44,560 Speaker 1: of this question of like, you know, isolating it from 706 00:38:44,560 --> 00:38:48,280 Speaker 1: the universe. We think that probably if it was totally separated, 707 00:38:48,320 --> 00:38:50,880 Speaker 1: you could just keep going, right, because even in a vacuum, 708 00:38:51,080 --> 00:38:54,240 Speaker 1: there's not nothingness. There's still stuff going on in that vacuum. 709 00:38:54,320 --> 00:38:57,799 Speaker 1: Yeah exactly. It's impossible to separate anything from the rest 710 00:38:57,800 --> 00:39:00,799 Speaker 1: of the universe because there's always like qual fields and 711 00:39:00,840 --> 00:39:03,560 Speaker 1: fluctuations and all this kind of stuff. And so that's 712 00:39:03,560 --> 00:39:06,319 Speaker 1: why it's fun to explore these things at a theoretical level, 713 00:39:06,360 --> 00:39:09,160 Speaker 1: like is this possible? And then it's a totally separate 714 00:39:09,239 --> 00:39:12,279 Speaker 1: question of like could you actually build these things? One 715 00:39:12,320 --> 00:39:15,840 Speaker 1: of the experimental obstacles to actually making this existing reality. 716 00:39:16,239 --> 00:39:18,640 Speaker 1: But there's this team at University of Maryland that put 717 00:39:18,719 --> 00:39:21,080 Speaker 1: this thing together and it kind of looks like they 718 00:39:21,160 --> 00:39:22,719 Speaker 1: did it, you know, it kind of looks like the 719 00:39:22,760 --> 00:39:26,160 Speaker 1: time crystal is real. That's so interesting. So this proof 720 00:39:26,200 --> 00:39:31,680 Speaker 1: of concept by being able to create these oscillating atoms 721 00:39:31,719 --> 00:39:33,880 Speaker 1: that you smack once and they're like all right, I 722 00:39:33,920 --> 00:39:36,319 Speaker 1: get it, I get it. I'll keep doing that, and 723 00:39:36,320 --> 00:39:40,120 Speaker 1: then you can use that information to maybe do more 724 00:39:40,239 --> 00:39:44,400 Speaker 1: work sort of in terms of like theoretical physics. Yeah exactly, 725 00:39:44,760 --> 00:39:47,480 Speaker 1: And that gives us some like understanding of you know, 726 00:39:47,560 --> 00:39:49,799 Speaker 1: what is the nature of time? Now that we know 727 00:39:49,880 --> 00:39:52,840 Speaker 1: that time crystals. We think the time crystals are a reality. 728 00:39:53,239 --> 00:39:56,160 Speaker 1: We can go back and use that to like help 729 00:39:56,280 --> 00:39:59,719 Speaker 1: guide us in building a deeper, more fundamental theory of 730 00:39:59,760 --> 00:40:03,319 Speaker 1: like quantum gravity that has the right respect for time, 731 00:40:03,360 --> 00:40:06,320 Speaker 1: that treats time more like an element of space time. 732 00:40:06,800 --> 00:40:09,480 Speaker 1: We think that the existence of time crystals points in 733 00:40:09,480 --> 00:40:13,480 Speaker 1: the direction that the general relativity concept of time is correct. 734 00:40:13,640 --> 00:40:16,240 Speaker 1: That doesn't mean that general relativities are right about everything 735 00:40:16,280 --> 00:40:19,400 Speaker 1: we know. It breaks down as singularities, but this basic 736 00:40:19,520 --> 00:40:22,879 Speaker 1: concept that space and time are deeply interwoven is more 737 00:40:22,920 --> 00:40:26,280 Speaker 1: likely to be true because time crystals exist. Right, Maybe 738 00:40:26,280 --> 00:40:30,640 Speaker 1: we're seeing a little more agreement between quantum mechanics and 739 00:40:30,680 --> 00:40:33,640 Speaker 1: general relativity than there was before. Can't we all just 740 00:40:33,680 --> 00:40:38,240 Speaker 1: get along? Community? Right? Community is the name of the day, 741 00:40:38,480 --> 00:40:41,680 Speaker 1: And also it's fun experimentally, like this is a really 742 00:40:41,680 --> 00:40:45,840 Speaker 1: important thing that might actually be useful technologically, imagine like 743 00:40:45,920 --> 00:40:50,160 Speaker 1: storing information. One thing that's difficult about building quantum computers 744 00:40:50,680 --> 00:40:52,839 Speaker 1: is that it's hard for them to have memories because 745 00:40:52,920 --> 00:40:56,520 Speaker 1: quantum objects these tiny little particles. They often like decay 746 00:40:56,640 --> 00:40:58,640 Speaker 1: and they don't last very long in the state that 747 00:40:58,680 --> 00:41:01,759 Speaker 1: you want. Well, time crystals might be a gray way 748 00:41:01,760 --> 00:41:05,799 Speaker 1: to build memory circuits for quantum computers because they are 749 00:41:05,880 --> 00:41:08,600 Speaker 1: stable in their lowest state and sort of remember the 750 00:41:08,640 --> 00:41:11,120 Speaker 1: configuration that you put them in. The pattern that you 751 00:41:11,160 --> 00:41:14,239 Speaker 1: put them in lasts through time. This is great for 752 00:41:14,280 --> 00:41:17,880 Speaker 1: our quantum hamster script because now we can get teeny 753 00:41:17,920 --> 00:41:22,799 Speaker 1: tiny computers for teeny tiny quantum hamsters. So that whole 754 00:41:22,800 --> 00:41:25,920 Speaker 1: scene where they're breaking into the quantum mainframe, that's gonna work. 755 00:41:26,480 --> 00:41:30,040 Speaker 1: Feeling good about this? Are they powered by tiny little 756 00:41:30,160 --> 00:41:33,120 Speaker 1: quantum cotton candies? That what gives the quantum hamster its power. 757 00:41:33,239 --> 00:41:35,000 Speaker 1: I mean, they got to keep up their carbs so 758 00:41:35,040 --> 00:41:38,439 Speaker 1: they can run in those tiny quantum wheels, keeping going. 759 00:41:38,600 --> 00:41:43,480 Speaker 1: Or maybe they should eat like scalloped crystal eyeballs. Now 760 00:41:43,480 --> 00:41:46,839 Speaker 1: we're getting into a horror movie. Oh yeah, that's right. 761 00:41:47,040 --> 00:41:50,120 Speaker 1: That's the Dark TV spinoff that will will sell after 762 00:41:50,200 --> 00:41:53,200 Speaker 1: the future. So this team in Maryland did this, and 763 00:41:53,239 --> 00:41:56,160 Speaker 1: then there's a team at Harvard that did something different. 764 00:41:56,200 --> 00:41:58,720 Speaker 1: They took a diamond, right, which is a space crystal, 765 00:41:59,160 --> 00:42:01,839 Speaker 1: and they put a bunch of nitrogen atoms inside that 766 00:42:01,880 --> 00:42:05,000 Speaker 1: diamond and then they turned those nitrogen atoms into a 767 00:42:05,160 --> 00:42:07,840 Speaker 1: time crystal by zapping it with a laser in a 768 00:42:07,960 --> 00:42:10,640 Speaker 1: very similar way. That's truly got to be a girl's 769 00:42:10,640 --> 00:42:14,799 Speaker 1: best friend. A diamond, and inside the diamond is a 770 00:42:14,800 --> 00:42:19,520 Speaker 1: time diamond. Yeah, exactly, a time diamond inside a space diamond. 771 00:42:19,840 --> 00:42:22,080 Speaker 1: That or it's like the taco bell version, you know, 772 00:42:22,400 --> 00:42:24,400 Speaker 1: take a burrito and wrap it in a taco and 773 00:42:24,400 --> 00:42:26,799 Speaker 1: then dip the whole thing in cheese. Either would be 774 00:42:26,800 --> 00:42:32,560 Speaker 1: good engagement gaps, I think exactly. So it's a really 775 00:42:32,600 --> 00:42:36,520 Speaker 1: exciting time sort of theoretically, like is this possible? There 776 00:42:36,560 --> 00:42:39,200 Speaker 1: was a lot of discussion. People fought for many years 777 00:42:39,200 --> 00:42:42,200 Speaker 1: that this was totally impossible. All the theorem suggested couldn't 778 00:42:42,239 --> 00:42:44,759 Speaker 1: be done, and then people found few loopholes, and then 779 00:42:44,800 --> 00:42:47,000 Speaker 1: a bunch of experimentalists when out there, said hey, we're 780 00:42:47,000 --> 00:42:48,840 Speaker 1: just gonna try to make this thing, and it looks 781 00:42:48,880 --> 00:42:51,759 Speaker 1: like they might have. So it's really fun for me 782 00:42:51,800 --> 00:42:54,080 Speaker 1: to see like a whole area of signs that people 783 00:42:54,360 --> 00:42:58,480 Speaker 1: didn't even consider as possible suddenly explode with activity and 784 00:42:58,680 --> 00:43:02,080 Speaker 1: ideas and in vation. That's the great thing about sciences. 785 00:43:02,160 --> 00:43:07,480 Speaker 1: You're always finding new things. Like you take old information, 786 00:43:08,000 --> 00:43:09,960 Speaker 1: you shake it up, and you find new things you 787 00:43:10,000 --> 00:43:13,520 Speaker 1: previously thought was impossible and now when I'm late to 788 00:43:13,600 --> 00:43:15,520 Speaker 1: an appointment, I can say, well, have you heard the 789 00:43:15,520 --> 00:43:18,399 Speaker 1: news about time crystals? Our whole concept of time might 790 00:43:18,400 --> 00:43:21,319 Speaker 1: not be right. That's right. Maybe I'm not late, maybe 791 00:43:21,360 --> 00:43:28,080 Speaker 1: you're late to Daniel says time can't be eternal. Anyway, 792 00:43:28,160 --> 00:43:31,680 Speaker 1: I've got a note from my physicist who says it's okay. 793 00:43:32,520 --> 00:43:35,920 Speaker 1: The larger motivation is that there are still really basic 794 00:43:36,040 --> 00:43:39,960 Speaker 1: questions out there, really big puzzles that haven't been solved 795 00:43:40,040 --> 00:43:42,759 Speaker 1: because nobody asked the right question or had the right 796 00:43:42,840 --> 00:43:46,480 Speaker 1: first idea. And so Frank Wilcheck is a little cookie, 797 00:43:46,520 --> 00:43:48,040 Speaker 1: but I love that he goes out there and tries 798 00:43:48,080 --> 00:43:50,800 Speaker 1: to tackle something that people think is impossible and actually 799 00:43:50,920 --> 00:43:54,480 Speaker 1: makes progress and makes a mistake, but along the way, 800 00:43:54,719 --> 00:43:57,080 Speaker 1: you know, breaks open a whole area of research. And 801 00:43:57,160 --> 00:43:59,719 Speaker 1: so somebody out there listening, hoping to grow up to 802 00:43:59,760 --> 00:44:02,040 Speaker 1: be a is just to make some big discovery. Don't 803 00:44:02,080 --> 00:44:04,200 Speaker 1: think that we figured it all out. We are far 804 00:44:04,400 --> 00:44:07,080 Speaker 1: from understanding the nature of the universe around us. There 805 00:44:07,120 --> 00:44:10,279 Speaker 1: are lots of really basic questions out there for you 806 00:44:10,520 --> 00:44:12,920 Speaker 1: to find the answers to. And if you're too afraid 807 00:44:13,000 --> 00:44:15,400 Speaker 1: to ask a question because you think it will be 808 00:44:15,480 --> 00:44:18,759 Speaker 1: stupid or wrong, you may never open up some really 809 00:44:18,760 --> 00:44:23,080 Speaker 1: interesting research avenues. Yeah, exactly, and remember even Nobel Prize 810 00:44:23,080 --> 00:44:26,319 Speaker 1: winners make mistakes. Take that Nobel Prize winner is not 811 00:44:26,480 --> 00:44:32,439 Speaker 1: so fancy now, are we? Well? Thank you guys so 812 00:44:32,520 --> 00:44:35,959 Speaker 1: much for listening. I hope you enjoyed our little time 813 00:44:35,960 --> 00:44:39,359 Speaker 1: Crystal time, and we will see you next time time 814 00:44:39,360 --> 00:44:42,480 Speaker 1: Crystal or not, we don't know, it's hard to say. 815 00:44:42,680 --> 00:44:52,840 Speaker 1: All right, thanks for listening everyone, Thanks for listening, and 816 00:44:52,880 --> 00:44:55,600 Speaker 1: remember that Daniel and Jorge Explain the Universe is a 817 00:44:55,640 --> 00:44:59,080 Speaker 1: production of My Heart Radio for More podcast for my 818 00:44:59,200 --> 00:45:02,759 Speaker 1: Heart Radio at the I Heart Radio app, Apple Podcasts, 819 00:45:02,880 --> 00:45:06,200 Speaker 1: or wherever you listen to your favorite shows. H