Latest / Daniel and Kelly’s Extraordinary Universe / What's a Time Crystal?

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What's a Time Crystal? · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Hey, Katie, did you know that if you stick any
0:11
Speaker 1: two science worse together you get a great science fiction
0:14
Speaker 1: movie title. Really? Is it really that easy? Oh yeah,
0:17
Speaker 1: just give it a shot. Okay, let's see Quantum Hamster Boom.
0:22
Speaker 1: I can see that whole movie in my mind alway, Yeah, okay, okay,
0:27
Speaker 1: what about Alligator Crystal? I love it? Want to see
0:31
Speaker 1: that one. Let's do time, Pump. I'm calling Netflix and
0:36
Speaker 1: set up a pitch meeting right now. Hi. I'm Daniel.
0:54
Speaker 1: I'm a particle physicist, and I really would like to
0:57
Speaker 1: write a science fiction movie someday. And I am Katie.
1:01
Speaker 1: I am a science podcaster, and I am already writing
1:06
Speaker 1: dialogue for Quantum Hamster in my head. And Welcome to
1:10
Speaker 1: the podcast Daniel and Jorge Explain the Universe, a production
1:14
Speaker 1: of I Heart Radio in which we take you on
1:16
Speaker 1: a tour of everything that's amazing in the universe, everything
1:20
Speaker 1: that's out there doing crazy stuff you couldn't imagine, and
1:23
Speaker 1: all the weird quantum stuff happening at the particle level
1:27
Speaker 1: and everything in between. But we want you to come
1:29
Speaker 1: away from our podcast not just hearing about the crazy
1:32
Speaker 1: stuff in the universe, but actually understanding it. And as
1:36
Speaker 1: you might have guessed, Orge isn't with us today, but
1:38
Speaker 1: instead we have a wonderful guest podcast host, Katie introduce
1:42
Speaker 1: yourself to everybody. Hi, guys, I am Katie Golden. I'm
1:45
Speaker 1: the host of Creature Feature, a podcast about animal and
1:49
Speaker 1: human behavior. I studied psychology and evolutionary biology, so I
1:55
Speaker 1: am very excited to take a journey into the physics
1:59
Speaker 1: realm of things. I hope I can fill Jorges shoes
2:03
Speaker 1: a little bit temporarily. Do you know what his shoe sizes.
2:07
Speaker 1: He's a cartoonist, so he just draws really big, floppy
2:09
Speaker 1: clown shoes and that'll be perfect for me. Well, you
2:14
Speaker 1: guys should all check out. Creature Feature is a super
2:16
Speaker 1: fun podcast, and Katie's a lot of fun, which is
2:19
Speaker 1: why we invite her here as a guest host. And
2:22
Speaker 1: you know, today's episode is all about how we understand
2:25
Speaker 1: the universe and how we understand things like time, which
2:28
Speaker 1: makes me wonder since you're an expert on creatures and
2:31
Speaker 1: evolutionary behavior, do animals understand time? Katie? That's a really
2:35
Speaker 1: good question. I'd say it depends on the animal, and
2:39
Speaker 1: it depends on what you mean by understand a lot
2:43
Speaker 1: of animals can kind of mark the passage of time
2:47
Speaker 1: without possibly really understanding it. Like there's a great migration
2:51
Speaker 1: of plankton that happens every day with the rising and
2:55
Speaker 1: setting of the sun. But could you say that as
2:57
Speaker 1: little zooplankton really understands time. I'm gonna say no, that's
3:01
Speaker 1: a bold, controversial take. But yeah, it's really hard to
3:05
Speaker 1: get inside of the heads of animals. That's a problem
3:08
Speaker 1: talk about on my podcast. Well, I wouldn't be surprised
3:11
Speaker 1: if animals like crows understood time. There's a group of
3:14
Speaker 1: crows that seem to always gather outside my window, right
3:17
Speaker 1: or like I'm two o'clock in the afternoon when I
3:19
Speaker 1: have a big zoom meeting. Yeah, I think patterns are
3:23
Speaker 1: really easy for animals to understand, especially the smart ones crows.
3:28
Speaker 1: If you feed them, they'll come back and visit you
3:30
Speaker 1: whenever you feed them, so they will learn your patterns,
3:33
Speaker 1: much like a cat. You know how your cat wakes
3:36
Speaker 1: you up just in time early in the morning for
3:38
Speaker 1: you to feed them. They understand patterns. They will memorize
3:42
Speaker 1: your rhythms and patterns for the best snacking opportunities. Well,
3:48
Speaker 1: you know, I was wondering if you were going to
3:50
Speaker 1: ask whether any animal understands time, even humans, because as
3:55
Speaker 1: you might know, time is a slippery topic and it's
3:58
Speaker 1: something a lot of our listeners ask us to talk
4:00
Speaker 1: about because it's not something that even human physicists can
4:04
Speaker 1: get our minds around. Why do we remember the past
4:07
Speaker 1: and not the future? Why is there now? Is the
4:09
Speaker 1: now actually real? Or is time just an illusion? All
4:12
Speaker 1: of these really simple basic questions about time haven't yet
4:16
Speaker 1: been answered. So wait is time? When we're talking about
4:20
Speaker 1: time though, is it just a human invention? Like we
4:23
Speaker 1: made clocks, we have one o'clock to twelve o'clock, you know,
4:26
Speaker 1: we kind of have this concept of time, like is
4:29
Speaker 1: it not just our human invention or is there actually
4:32
Speaker 1: a real thing of time outside of our little mickey
4:37
Speaker 1: mouse watches. Yeah, it's a great question. There's a lot
4:40
Speaker 1: of it that is invented by humanity, like units, you know,
4:43
Speaker 1: one second, one minute, that's totally arbitrary, and an alien
4:46
Speaker 1: species might invent something totally different. But in our understanding
4:50
Speaker 1: of physics, time seems to be real, and we will
4:53
Speaker 1: dig into that later in the podcast about the concept
4:56
Speaker 1: of time in quantum mechanics. And the concept of time
4:58
Speaker 1: in general relativity, which turned out to be totally fundamentally
5:02
Speaker 1: different ideas of what time is. But yeah, we do
5:05
Speaker 1: think the time is a feature of the universe. We
5:08
Speaker 1: think it's something out there and real, but we won't
5:11
Speaker 1: really know until we one day get to talk to
5:13
Speaker 1: alien physicists and see if they even understand the concept
5:17
Speaker 1: of time. That's so interesting. So there is an actual
5:21
Speaker 1: cosmic time that is occurring that we sort of view
5:26
Speaker 1: through our own little human lens, our sun dials and
5:29
Speaker 1: our watches and our appointments, but that may not really
5:32
Speaker 1: capture the whole truth about what time is. Yeah, or
5:35
Speaker 1: it could be an illusion. It could be the time
5:37
Speaker 1: is not something deep and fundamental to the universe. It
5:40
Speaker 1: could be that it's sort of emerges that it's like
5:42
Speaker 1: a special condition that only happens under certain circumstances, you know,
5:46
Speaker 1: the way like ice forms sometimes in the universe, but
5:49
Speaker 1: not always. You could have a universe without ice. That's
5:52
Speaker 1: not a big deal. It might be the time isn't fundamental.
5:56
Speaker 1: But we'll dig into all that on today's podcast. We
5:58
Speaker 1: actually want to focus today on something even weirder than
6:01
Speaker 1: just the question of time, which is a big puzzle
6:04
Speaker 1: for physicist. We want to talk about something which has
6:06
Speaker 1: been bopping around the Internet and creating a lot of
6:09
Speaker 1: buzz recently. That's this topic of time crystals. Oh, that
6:13
Speaker 1: sounds beautiful. What comes into your mind when I said it?
6:16
Speaker 1: For his time crystals a bunch of clocks floating around
6:20
Speaker 1: in a crystalline structure. All right, And so today on
6:25
Speaker 1: the program we'll be asking and hopefully answering the question
6:33
Speaker 1: what is a time crystal? So, Daniel, you asked people
6:39
Speaker 1: on the internet what they thought. That's right. Folks out
6:42
Speaker 1: there volunteered to speculate baselessly on the topic of the day,
6:46
Speaker 1: just to give us a sense for what they knew
6:48
Speaker 1: and what they didn't know. And so if you would
6:51
Speaker 1: like to submit your baseless speculations for future podcast episodes,
6:55
Speaker 1: please write to me two questions at Daniel and Jorge
6:58
Speaker 1: dot com. And so here is what people had to say.
7:02
Speaker 1: My only thought is that there are these points in
7:06
Speaker 1: space that maybe our time markers, or there are certain
7:12
Speaker 1: blocks of crystals that hold elements or signatures of certain
7:17
Speaker 1: time events that you can look back on. That's easy.
7:22
Speaker 1: Um made a whole Rick and Morty episode about those.
7:25
Speaker 1: I don't know what time crystals are. Well, I know
7:27
Speaker 1: about Courts is a crystal, and we use courts to
7:32
Speaker 1: get precision timing and watches and things like that. Maybe
7:37
Speaker 1: there's other crystals that can do the same thing. So
7:40
Speaker 1: what do you think about those answers, Katie? I do
7:42
Speaker 1: like the call back to Rick and Morty. They definitely
7:46
Speaker 1: have a scientific approach to time with all of their
7:49
Speaker 1: time travel episodes, do they? Though? Are you a Rick
7:51
Speaker 1: and Morty fan? I like it it's a loaded question
7:54
Speaker 1: to ask if you're a Rick and Morty fan, because
7:56
Speaker 1: I think that there are some really hardcore fans out
7:59
Speaker 1: there who will contends that you have to really understand
8:02
Speaker 1: science to understand the show, and I just think it's
8:05
Speaker 1: a fun show. Yeah, well, you know, I watch Rick
8:07
Speaker 1: and Morty sometimes, but I'm a real stickler for getting
8:11
Speaker 1: the science right when you're doing time travel, and that's
8:14
Speaker 1: really hard. It's very difficult to have a narrative that
8:17
Speaker 1: makes sense if you're also going backwards in time and
8:20
Speaker 1: jumping all around, and so that sometimes gets the way
8:23
Speaker 1: of me enjoying Rick and Morty. I see, you're real
8:26
Speaker 1: stickler for those time travel plot holes that always pop up. Yeah, exactly.
8:32
Speaker 1: Speaking of time, the focus of today's episode is this question,
8:36
Speaker 1: what is a time crystal? I like some of these answers.
8:39
Speaker 1: You know, we do use a crystal in watches sometimes
8:42
Speaker 1: to tell time, right, crystals are at the heart of
8:45
Speaker 1: a lot of watches on people's risks. How do they
8:48
Speaker 1: work to tell time? Do you have just a little
8:50
Speaker 1: crystal man in your watch going like it's about two thirty?
8:54
Speaker 1: That's exactly how it works. You crack it open, you'll
8:56
Speaker 1: spot we're writing a Rick and Morty episode. But that's
9:03
Speaker 1: not actually the kind of time crystal that we're talking
9:05
Speaker 1: about today. Today's episode is about something totally different. So
9:08
Speaker 1: what kind of time crystal are we talking about? If
9:11
Speaker 1: it's not a little crystal telling you what time it is.
9:14
Speaker 1: The idea of a time crystal basically is an extension
9:17
Speaker 1: of the idea of a space crystal. So let's first
9:21
Speaker 1: talk about what a space crystal is, remind ourselves about
9:23
Speaker 1: like the basic idea there, and then we'll try to
9:26
Speaker 1: apply that concept to time crystals. Now, I'm imagining a
9:30
Speaker 1: crystal floating through space, but I'm going to guess that's
9:33
Speaker 1: probably not what it is. No, exactly that's exactly what
9:36
Speaker 1: it is for a space crystal, right, A space crystal
9:39
Speaker 1: is what it's just like a regular pattern and a
9:42
Speaker 1: crystal like the kind of thing that you see like
9:44
Speaker 1: a shiny gem or something else you would call a
9:46
Speaker 1: crystal is if you zoom down into it and understood
9:49
Speaker 1: it like at the molecular or the atomic level. The
9:52
Speaker 1: way it's built is like a bunch of Lincoln logs
9:56
Speaker 1: or something. You have regularly spaced atoms all end up
10:00
Speaker 1: in like a three dimensional pattern. Right, It's that kind
10:03
Speaker 1: of grid like structure. I always think of a sort
10:06
Speaker 1: of a wafer kind of treat, maybe just because I'm hungry,
10:09
Speaker 1: but it's those layers and layers of interlocking wafer like
10:13
Speaker 1: molecular structures. Right, Yeah, exactly. You have wafer and then
10:17
Speaker 1: you have caramel, then you have another wafer, then you
10:20
Speaker 1: have chocolate. That's exactly the recipe for building your crystal.
10:23
Speaker 1: Just making me hungrier, Katie's crystal cookies, I love it. Well.
10:27
Speaker 1: Sugar is a crystal. Yes, sugar is a crystal. And
10:30
Speaker 1: basically anything that's a crystal that has a regular pattern.
10:33
Speaker 1: And that's the core concept that we have to understand
10:36
Speaker 1: when we're talking about crystals. Basically, you're building a lattice.
10:39
Speaker 1: You're taking a continuous symmetry right like space in itself
10:44
Speaker 1: is the same everywhere. It doesn't really matter if you
10:46
Speaker 1: take one step forward or a half step forward. The
10:49
Speaker 1: same laws of physics reply, everything works the same way.
10:52
Speaker 1: If you're gonna like juggle balls here, then you took
10:55
Speaker 1: a step sideways, the same rules should apply, the same
10:58
Speaker 1: juggling should work. A crystal takes that and sort of
11:01
Speaker 1: breaks that symmetry into something discreet. So now the universe
11:05
Speaker 1: has a symmetry still, but it's not like smooth. You
11:09
Speaker 1: have to take like exactly the right size step in
11:12
Speaker 1: order to see the universe the same way. So if
11:14
Speaker 1: you're like inside a big crystal is a huge lattice
11:17
Speaker 1: and you're sitting on an atom, you have to take
11:19
Speaker 1: a step exactly the size of the lattice so that
11:21
Speaker 1: you're still sitting on an atom. It's chess rules, except
11:24
Speaker 1: you're all ponds. Yeah, exactly, take space and break it
11:28
Speaker 1: up into chessboards, and you can only move one square
11:30
Speaker 1: or two squares. You can't move one and a half
11:32
Speaker 1: or two and a half squares. And so that's the
11:35
Speaker 1: idea of a space crystal, and like do you think
11:37
Speaker 1: of a crystal is a big shiny thing, But when
11:39
Speaker 1: you zoom down into it, the reason that it's shiny,
11:41
Speaker 1: the reason it has those properties that reflect LFE that way,
11:45
Speaker 1: is because it has this regular structure in space. So
11:48
Speaker 1: when we say crystal here, we generally just mean like
11:51
Speaker 1: a regular, discrete structure. That's so interesting. I mean, crystal
11:55
Speaker 1: structures are really interesting and evolutionary biology because they are
12:00
Speaker 1: surprisingly sometimes used in eyeballs, like in the eyes of
12:06
Speaker 1: mollusks will have these guanting crystal structures that help them
12:10
Speaker 1: reflect light. You don't think of organic material as something
12:15
Speaker 1: you can turn into a crystal, but yeah, you can
12:17
Speaker 1: take guanting form a guanting crystal form an eyeball. That's fascinating.
12:21
Speaker 1: So most eyeballs don't have crystals in them. It's a
12:24
Speaker 1: special situation. Yeah, we have lenses in most eyeballs, but
12:27
Speaker 1: those guanting crystals that form in certain eyeballs, like in
12:31
Speaker 1: the eyes of scalps, will have this characteristic that helps
12:35
Speaker 1: them reflect light in such a way that gives them
12:38
Speaker 1: really interesting vision. And scallops have eyes, yes they do.
12:43
Speaker 1: You wouldn't think so, I'll think about that. Next time
12:46
Speaker 1: i'm biting into one, I'm tasting crystalline eyeballs. They're actually
12:50
Speaker 1: beautiful blue eyes and they have a whole mess of them,
12:53
Speaker 1: like two hundred of them. Oh my gosh, Well that
12:56
Speaker 1: makes me feel better. That's why I don't eat scalops
12:58
Speaker 1: because I don't like crystalline eyeballs. And instead of using
13:01
Speaker 1: lenses like a human or mammal eye or most animals eyes,
13:05
Speaker 1: they actually use mirrors inside of their eyes as kind
13:09
Speaker 1: of a miniature telescope by using that guanting crystal structure. Wow, amazing. Well,
13:14
Speaker 1: the other important thing to understand about these kinds of
13:17
Speaker 1: crystals that we're talking about space crystals is that they
13:20
Speaker 1: are stable. So like those crystals in the eyes of scallops,
13:23
Speaker 1: or that diamond that comes up out of the ground
13:26
Speaker 1: is stable as the regularly repeating pattern, but it doesn't
13:29
Speaker 1: fall apart. It is in its lowest energy state, and
13:32
Speaker 1: so we can hang out basically for a long time.
13:34
Speaker 1: It needs to be broken up if you want those
13:36
Speaker 1: atoms back. Is that why diamonds are so tough because
13:40
Speaker 1: of that crystalline structure. Yeah, because the crystalline structure makes
13:44
Speaker 1: them really hard to break. And also that's why they
13:46
Speaker 1: last a long time because they're in a stable state.
13:49
Speaker 1: Like the atoms, they're very happy to be in that situation.
13:51
Speaker 1: They're not going to relax into some other lower ground
13:54
Speaker 1: state and then break up into something else energetically. They're
13:58
Speaker 1: very comfortable. That's so interesting. It's something like an ice
14:01
Speaker 1: cube forms a lot of structure, but it does melt.
14:04
Speaker 1: So is that an example of like an unstable crystal structure. Yeah.
14:09
Speaker 1: Ice is actually super fascinating because it can form lots
14:12
Speaker 1: of different kinds of structures. And we're gonna do a
14:14
Speaker 1: whole podcast episode about all the different weird kinds of ice.
14:17
Speaker 1: It's like one that's not transparent black ice, and it's
14:20
Speaker 1: like nine other kinds of ice. So it can form
14:23
Speaker 1: lots of weird crystal structures, but actually is in a
14:26
Speaker 1: stable state. The only reason it melts is because you're
14:28
Speaker 1: adding energy to it. Right. Melting means you're like heating
14:31
Speaker 1: it up from the outside. Same with diamonds. You put
14:33
Speaker 1: diamonds in hot enough temperatures, they will melt. That actually happens.
14:37
Speaker 1: We think sort of like on the surface of Jupiter,
14:40
Speaker 1: which rains diamonds into the interior, which might form like
14:43
Speaker 1: a big liquid diamond ocean. So Jupiter is really rich,
14:47
Speaker 1: talking about Kardashian levels of rich. Absolutely, absolutely, So now
14:52
Speaker 1: we understand, like the idea of a crystal, it's like
14:55
Speaker 1: a regular structure, but that's a crystal structure in space.
14:58
Speaker 1: So now it's turned to the topic we're trying to
15:00
Speaker 1: talk about today, which is time crystals. Right, take that
15:03
Speaker 1: same idea and apply it to time. Okay, but how
15:06
Speaker 1: do you put time in a crystal? Because time is
15:09
Speaker 1: not physical matter. You can't arrange it in a lott
15:12
Speaker 1: of structure. So what are you trying to say here?
15:15
Speaker 1: So take the same idea you're applying to a lattice
15:18
Speaker 1: in space, where you say, all right, the thing looks
15:21
Speaker 1: the same if I take one step to the right,
15:23
Speaker 1: or one step forward or one step backwards. And now
15:25
Speaker 1: say what happens if I take a step forwards in time?
15:29
Speaker 1: So a time crystals some kind of object or substance
15:32
Speaker 1: which has a regular repeating pattern in time, which means
15:36
Speaker 1: like it looks the same now and then in a second,
15:39
Speaker 1: and then in two seconds, and then in three seconds
15:41
Speaker 1: and in between. It doesn't have to look the same,
15:44
Speaker 1: but it's going through some transformation so regularly returns to
15:48
Speaker 1: the same position. So this is like four dimensional chess
15:52
Speaker 1: where it's like you're playing this chess game where you're
15:55
Speaker 1: only allowed to move one space at a time in
15:58
Speaker 1: a certain direction, but it through time and not through
16:02
Speaker 1: physical space necessarily, Yes, exactly. And so what you want
16:06
Speaker 1: is something which returns to the same configuration, but after
16:09
Speaker 1: discrete units of time, right, not like it's in that
16:12
Speaker 1: same state all the time. That would just be a
16:14
Speaker 1: space crystal. You want a time crystal which is in
16:17
Speaker 1: a certain configuration, then moves out of it and comes back,
16:20
Speaker 1: and then moves out of it and then comes back.
16:23
Speaker 1: So you wanted to sort of break this continuous time
16:26
Speaker 1: symmetry where things always look the same into a discrete symmetry,
16:30
Speaker 1: so that it looks the same and then it doesn't,
16:32
Speaker 1: and then it comes back and it looks the same again.
16:35
Speaker 1: That's the property you have in a space crystal, right,
16:37
Speaker 1: you have this distance between points in space. Now we
16:39
Speaker 1: want distance between configurations in time. Kind of sounds like
16:43
Speaker 1: a dance to me. You have to do your dance
16:47
Speaker 1: movements through not just space, but through time, and it
16:50
Speaker 1: has to synchronize in a specific way. Yes, exactly, And
16:54
Speaker 1: the other critical thing is that it has to be stable,
16:58
Speaker 1: meaning it has to be in its grounds eight. That
17:00
Speaker 1: means that basically it's doing this forever. So you need
17:04
Speaker 1: something which is both in motion but also in the
17:07
Speaker 1: most relaxed, lowest energy state, and that's a really unusual combination.
17:12
Speaker 1: You have to imagine something basically moving forever that sounds
17:16
Speaker 1: like a perpetual motion, which I didn't realize is something
17:20
Speaker 1: you could do. Well, my mind is blown, so I'm
17:23
Speaker 1: going to try to recollect my brain back into pieces.
17:26
Speaker 1: But before we do that, let's take a quick break.
17:41
Speaker 1: And we're back and Daniel is trying to reassemble the
17:45
Speaker 1: pieces of my brain that exploded. Because we were talking
17:49
Speaker 1: about how there is something where with a time crystal
17:54
Speaker 1: you can remain in emotion forever at a low energy state,
17:59
Speaker 1: which sounds like perpetual motion to me, which I thought
18:03
Speaker 1: was just science fiction. So how could this possibly happen? Yeah,
18:06
Speaker 1: it's a really awesome question. And it's for this reason
18:08
Speaker 1: that people thought forever like this is a silly idea.
18:11
Speaker 1: Nobody should even talk about it. It's obviously impossible, and
18:15
Speaker 1: it's only recently that people thought maybe there's a way
18:18
Speaker 1: to make this happen. Maybe there's a way to configure
18:21
Speaker 1: a system that can be in motion through time where
18:25
Speaker 1: regularly returns to a specific state that's one of the
18:28
Speaker 1: lattest point and yet is stable. So we could like
18:31
Speaker 1: do this forever. And this started in about twenty twelve
18:35
Speaker 1: when a famous physicist named Frank Wilcheck. He's at m
18:39
Speaker 1: I T and he won the Nobel Prize for understanding
18:41
Speaker 1: the strong interaction, which is a thing that like binds
18:44
Speaker 1: quirks together into protons and neutrons. So he's generally a
18:47
Speaker 1: smart guy, and he's also kind of famous for coming
18:50
Speaker 1: out of left field with a crazy idea that turns
18:53
Speaker 1: out to be pretty good. He's the guy, for example,
18:55
Speaker 1: who coined the term axons to describe that hypothetical particle,
18:59
Speaker 1: and in he put out this kind of crazy paper saying,
19:02
Speaker 1: you know what, here's a situation where time crystals might
19:05
Speaker 1: be possible. He constructed an example of a quantum system,
19:10
Speaker 1: a ring of particles that sort of rotates and every
19:14
Speaker 1: sort of clock cycle returns to a similar configuration and
19:17
Speaker 1: repeats the same pattern in time. So exploded into like
19:22
Speaker 1: the community of theoretical physics blowing everybody's mind. So is
19:25
Speaker 1: this something that would happen on the quantum level. Are
19:29
Speaker 1: we talking about entire like star systems doing this like
19:34
Speaker 1: time crystal thing, or are we talking about something on
19:36
Speaker 1: a very small scale. This is something a very small scale.
19:39
Speaker 1: This would definitely be a quantum effect. It's not the
19:42
Speaker 1: kind of thing that you can have happened from macroscopic systems.
19:45
Speaker 1: And the reason you can only do it potentially for
19:48
Speaker 1: quantum systems is that quantum systems have a really weird
19:51
Speaker 1: relationship with zero energy. Right. Things that the quantum scale
19:55
Speaker 1: can never have exactly zero energy, so when you force
19:59
Speaker 1: them into their howest energy state, it's not actually down
20:02
Speaker 1: to zero energy. But a whole fun podcast episode recently
20:05
Speaker 1: about zero point energy in the Casimir effect, which basically
20:09
Speaker 1: says if you look into empty space, it's actually filled
20:12
Speaker 1: with an infinite number of photons because all the fields
20:16
Speaker 1: that are out there in space can never really relax
20:19
Speaker 1: down to zero energy. So time crystals, if you think
20:22
Speaker 1: they're possible, could only be possible for tiny, little microscopic
20:27
Speaker 1: quantum particles. This is like when my car battery drained
20:30
Speaker 1: down to quote unquote zero and the mechanics that I
20:33
Speaker 1: need a new one, But hey, guess what, I got
20:35
Speaker 1: a little bit more out of that battery. So maybe
20:38
Speaker 1: it was some quantum time crystals at work there. Or
20:42
Speaker 1: when your iPhone battery says it's at zero but it's
20:45
Speaker 1: still running, and you're like, am I using the Casimir
20:48
Speaker 1: effect to charge my bode? And you might also be imagining,
20:51
Speaker 1: you know, obvious examples of like larger physical systems, not
20:55
Speaker 1: just stars, that seem to have this property that they
20:57
Speaker 1: could spin, for example, and return to the same state.
21:00
Speaker 1: Like think about a wheel with spokes. As it rotates,
21:03
Speaker 1: it returns to basically the same configuration. The problem is
21:06
Speaker 1: that bicycle wheels, a macroscopic object, could never actually spin forever.
21:11
Speaker 1: And that's also not its ground state. It's not the
21:13
Speaker 1: most lowest energy state. Lowest energy state for a bicycle
21:17
Speaker 1: wheel is when it's stopped right, And so that's why
21:19
Speaker 1: we aren't able to actually make a perpetual motion machine
21:23
Speaker 1: out of bicycle wheels and water and marbles and so
21:26
Speaker 1: on and so forth. But Frank will Check wrote this
21:28
Speaker 1: paper and said, you know what, it might be possible
21:30
Speaker 1: for quantum objects, basically like a little quantum wheel. He
21:34
Speaker 1: tried to show this thing could spin forever and actually
21:37
Speaker 1: be in its ground state. Now. Of course this set
21:40
Speaker 1: off like a lot of conversations in the theoretical physics community.
21:43
Speaker 1: And there's another theorist, Patrick Bruno, who actually found a
21:46
Speaker 1: mistake in well checked paper tattletale. I know this, but
21:51
Speaker 1: this is a good lesson, like Nobel Prize winners make mistakes.
21:54
Speaker 1: I feel like a lot of times people quote Nobel
21:56
Speaker 1: Prize winners and if they said it and they want
21:58
Speaker 1: a Nobel Prize in must be the truth, right, But
22:02
Speaker 1: like they're just people. You know, Yes, they're smart and
22:04
Speaker 1: they got lucky, but they're also people and sometimes they
22:07
Speaker 1: make mistakes. Ye take that, you Nobel Prize winning smarty pants.
22:13
Speaker 1: I especially love it when they interview a Nobel Prize
22:16
Speaker 1: winner on a topic they're like, not an expert in
22:19
Speaker 1: you know, you'll hear like a Nobel Prize winning physicist
22:21
Speaker 1: commenting on economic policy and you're like, you don't know
22:24
Speaker 1: anything more about that than anybody else, Like just because
22:27
Speaker 1: he won the Nobel Prize, Yeah, you know, I'm as
22:31
Speaker 1: much a Nobel Prize winner in a field you didn't
22:34
Speaker 1: study as you are Nobel Prize winner in physics. So they're, yeah,
22:38
Speaker 1: exactly what was this mistake and how did that change
22:42
Speaker 1: this whole concept of being able to have these little,
22:45
Speaker 1: little tiny time crystals. Yeah. So Patrick Bruno showed that
22:48
Speaker 1: the example that will Check proposed, this idea of a
22:52
Speaker 1: ring of particles rotating was actually more similar to a
22:55
Speaker 1: bicycle wheel spinning than we thought that he would only
22:58
Speaker 1: rotate if it was actually in a more energetic state,
23:01
Speaker 1: and he showed that the example that will Check suggested
23:04
Speaker 1: had the possibility to decay into a ground state which
23:07
Speaker 1: wouldn't be rotating, and so it wouldn't actually qualify as
23:10
Speaker 1: a time crystal. But you know, once the idea is
23:13
Speaker 1: out there, then people started working on They thought, that's interesting,
23:16
Speaker 1: let's reinvestigate a lot of times you have an area
23:19
Speaker 1: in physics where people are like, oh, we already know
23:21
Speaker 1: the answer there, that's totally impossible, and it takes one
23:24
Speaker 1: brave person like dig into again and ask the question anew,
23:28
Speaker 1: and then a lot of people will follow and be like, oh,
23:30
Speaker 1: that's interesting, I wonder if we could actually crack this problem.
23:33
Speaker 1: And so Frank will Checks credit with like cracking this
23:35
Speaker 1: problem open again, and then a huge number of people
23:38
Speaker 1: started writing papers, and there were a lot of people
23:40
Speaker 1: that said, oh no, it turns out of time crystals
23:42
Speaker 1: completely impossible. They wrote all these no go papers that
23:45
Speaker 1: proved under various conditions. You could never have a time crystal.
23:49
Speaker 1: You can never have a quantum mechanical arrangement of particles
23:52
Speaker 1: that repeats in time and is at its ground state.
23:55
Speaker 1: Wet blankets trying to make it so that I can't
23:58
Speaker 1: make a little quantum circus with a little merry go round,
24:02
Speaker 1: and I'm thinking about cork on a unicycle just going
24:06
Speaker 1: on forever, and I don't like it. I want to
24:07
Speaker 1: hear some optimism. Well, we'll talk about the actual experiments
24:11
Speaker 1: in a minute, because this also inspired a bunch of
24:13
Speaker 1: folks to say, well, let's go see if we can
24:16
Speaker 1: make one. You know, sometimes the theorists say that's as possible,
24:19
Speaker 1: this is impossible, but it's up to the universe to
24:22
Speaker 1: decide whether it actually happens. And so I like when
24:25
Speaker 1: experimentalists sort of don't listen to the theorists and just
24:28
Speaker 1: go out there and explore. But it's actually really interesting
24:32
Speaker 1: and important question about time crystals because it gets to
24:35
Speaker 1: the heart of how we think about time. And this
24:37
Speaker 1: is something you were bringing up earlier, like is time
24:40
Speaker 1: or real thing? If time crystals are really really would
24:43
Speaker 1: tell us something fundamental about the nature of like time
24:46
Speaker 1: and the universe. Yeah, because I feel like we don't
24:49
Speaker 1: really have a frame of reference outside of our human
24:53
Speaker 1: invention of We mark the minutes, we mark the seconds.
24:57
Speaker 1: We pick sort of these units of time, probably based
25:01
Speaker 1: on our ability to like the time it takes us
25:03
Speaker 1: to think about a second, is about how long a
25:06
Speaker 1: second is, So you know, it's based very much on
25:09
Speaker 1: our human brains. But it's interesting. I guess I've never
25:13
Speaker 1: really thought too much about finding empirical evidence for their
25:17
Speaker 1: being time. Well, it's also really interesting to sort of
25:20
Speaker 1: dig into it theoretically and ask, like our fundamental picture
25:24
Speaker 1: of the universe, what does that tell us about time?
25:28
Speaker 1: And we have two pictures of the universe the way
25:30
Speaker 1: things work sort of at the deepest level in the universe,
25:33
Speaker 1: quantum mechanics and general relativity. And as listeners the podcast know,
25:38
Speaker 1: these two don't often agree, and that's also the case
25:41
Speaker 1: about the nature of time. Have very different opinions about
25:45
Speaker 1: what time is, and quantum mechanics says that space and
25:50
Speaker 1: time are very different, and according to quantum mechanics, you
25:53
Speaker 1: have like a description of the universe. It says like,
25:55
Speaker 1: here's your quantum particle, there's your quantum particle, whatever. And
25:58
Speaker 1: you know, quantum mechanics tells us what's likely to happen
26:01
Speaker 1: to those particles in the future, and all that crazy
26:04
Speaker 1: stuff that we can dig into another episode. But the
26:07
Speaker 1: important thing is that quantum mechanics tells us how those
26:10
Speaker 1: quantum states evolved, like the Shortinger equation, the most famous equation,
26:14
Speaker 1: and quantum mechanics, that's what it does. It tells us,
26:17
Speaker 1: if you have a quantum state, here's what it's going
26:18
Speaker 1: to look like in the future. And also you can
26:21
Speaker 1: turn that equation around and you can say, here's how
26:24
Speaker 1: you got to now, here's how the past must have
26:27
Speaker 1: looked if the present looks this way. And there's a
26:30
Speaker 1: concept we often talk about called quantum information, and that's
26:33
Speaker 1: what this means. It says that if you know how
26:36
Speaker 1: the universe looks now, you can figure out how we
26:38
Speaker 1: got here because quantum information is never destroyed. And that's
26:42
Speaker 1: a deep and fundamental statement about the nature of the
26:44
Speaker 1: universe because it means, according to quantum mechanics, the time
26:48
Speaker 1: is eternal time like goes on forever into the future
26:52
Speaker 1: and into the past. So that's true of quantum mechanics,
26:56
Speaker 1: like in the quantum miniature universe, but like when we
27:00
Speaker 1: look at the larger universe, once we scale it up,
27:03
Speaker 1: those ideas don't hold true. Yeah, exactly. This is relevant
27:06
Speaker 1: to the rules of tiny little particles. But you're right,
27:09
Speaker 1: when we scale up to the rest of the universe,
27:11
Speaker 1: things do look a little different. And this is when
27:13
Speaker 1: general relativity comes in, because when it comes to like
27:16
Speaker 1: the shape of the universe and the age of the universe,
27:19
Speaker 1: the thing that matters most is gravity, and general relativity
27:23
Speaker 1: is the best theory we have that describes how gravity works.
27:26
Speaker 1: And the most important concept in general relativity that's relevant
27:30
Speaker 1: for today's conversation is this notion that space and time
27:33
Speaker 1: are very deeply connected, or quantum mechanics says space time
27:37
Speaker 1: are separate. Time is just like the way that things
27:40
Speaker 1: in space evolve one step to the other. General relativity says, no, no, no,
27:45
Speaker 1: Time is like just one part of this thing we
27:47
Speaker 1: call space time, and there's a deep symmetry between space
27:51
Speaker 1: and time, and they evolve together and they get twisted
27:54
Speaker 1: together and they really closely connected. And if you think
27:57
Speaker 1: about what general relativity says about time even more deeply,
28:00
Speaker 1: you know, general relativity says that the universe is expanding
28:04
Speaker 1: and that it used to be denser, and as you
28:06
Speaker 1: look backwards in time, time doesn't go on forever. It
28:08
Speaker 1: comes back to some sort of like singularity in the
28:11
Speaker 1: early universe. And according to general relativity, is very natural,
28:14
Speaker 1: for example, to have a beginning of time, for time
28:17
Speaker 1: to have started rum zero in the early universe. So
28:21
Speaker 1: quantum mechanics says space and time very different and time
28:24
Speaker 1: has lasted forever. General relativity says, no, no no, no, These
28:28
Speaker 1: are just two different sides of the same coin. And
28:30
Speaker 1: it makes perfect sense for time to have started in
28:32
Speaker 1: the early universe. So two very different pictures about this
28:35
Speaker 1: very basic piece of the universe. Well, the universe is
28:39
Speaker 1: made out of quantum particles, and so the bigger aspects
28:43
Speaker 1: of the universe are made up of the quantum aspects
28:46
Speaker 1: of the universe. So it's very interesting that you have
28:49
Speaker 1: this disagreement ostensibly between basically the some of the parts
28:54
Speaker 1: and the parts themselves. Yeah, you're absolutely right, And one
28:58
Speaker 1: of the reasons they disagree is that usually they play
29:00
Speaker 1: in different fields. When we talk about tiny little particles,
29:04
Speaker 1: gravity is so weak that it's basically irrelevant, and we
29:07
Speaker 1: can ignore what general relativity says. And then when we
29:10
Speaker 1: zoom up to talk about stars and planets, all those
29:13
Speaker 1: tiny little particles are so small they get just averaged out.
29:15
Speaker 1: All the quantum effects basically disappear. So general relativity is
29:19
Speaker 1: dominant for really big heavy stuff, and quantum mechanics are
29:23
Speaker 1: dominant for really tiny, very low mass stuff. And it's
29:26
Speaker 1: very rare for the two to be important, so we
29:29
Speaker 1: can't tell like who wins when they're both important. The
29:32
Speaker 1: only way to figure that out is to do things
29:34
Speaker 1: like look inside of a black hole, where things are
29:36
Speaker 1: so small but so dense that both of them are important.
29:41
Speaker 1: And that's not something we've been able to do yet,
29:44
Speaker 1: not yet. Maybe in a few years. Well, I want
29:46
Speaker 1: to hear about how this disagreement impacts whether or not
29:50
Speaker 1: I can have my tiny time crystal Carnival. But maybe
29:55
Speaker 1: we should take a quick break first of while I
29:57
Speaker 1: draw up some little quantum merrigo rounds schematics. We are back.
30:14
Speaker 1: I'm trying to decide whether to sell cotton candy at
30:18
Speaker 1: my little quantum Carnival with the time crystal Dance, the
30:22
Speaker 1: time crystal Carousel, And so Daniel is going to explain
30:27
Speaker 1: to me how quantum mechanics and general relativity, the small
30:33
Speaker 1: side of the universe, the quantum side, and the big side,
30:36
Speaker 1: the US and stars and everything else can disagree so
30:40
Speaker 1: much about time and space. Yeah, well, I wish we
30:43
Speaker 1: knew the answer to that. But one way that we
30:45
Speaker 1: might be able to probe it is to look inside
30:48
Speaker 1: the core of a black hole and understand, you know,
30:51
Speaker 1: who's right about the nature of the universe, or go
30:53
Speaker 1: back in time to the Big Bang. But you know
30:55
Speaker 1: that's kind of inaccessible. So we're excited anytime we can
30:59
Speaker 1: probe thing that we think gets near this question that
31:02
Speaker 1: lets us like understand around the edges of these questions
31:05
Speaker 1: about the fundamental nature of the universe. And that's why
31:08
Speaker 1: time crystals are super fascinating because they explore this connection
31:13
Speaker 1: between space and time. Like if time crystals can actually
31:17
Speaker 1: be made, it's really a strong argument that there's a
31:21
Speaker 1: close connection between space and time, that this thing that
31:24
Speaker 1: exists in space space crystals can also be made in time,
31:27
Speaker 1: that time can be seen sort of like as another
31:30
Speaker 1: dimension of space. It adds sort of like a check
31:33
Speaker 1: in the column of general relativity. And so that would
31:36
Speaker 1: mean that quantum mechanics is actually behaving in a way
31:41
Speaker 1: that is following the rules of general relativity. It would
31:45
Speaker 1: mean that we need to adapt somehow quantum mechanics to
31:48
Speaker 1: play along nicely with this concept that space and time
31:51
Speaker 1: are deeply connected. And you know, we know already that
31:55
Speaker 1: quantum mechanics can't really be right about time being eternal
31:58
Speaker 1: in every direction, like we think the universe had a beginning,
32:02
Speaker 1: So it doesn't really make sense to hold tightly to
32:04
Speaker 1: this concept that time must be eternal. On the other hand,
32:08
Speaker 1: it's a pretty big thing to get rid of, to
32:10
Speaker 1: let go of this concept of quantum unitarity, that quantum
32:14
Speaker 1: information is not ever lost. That's something we really think
32:18
Speaker 1: is that the foundation of quantum mechanics. So one of
32:20
Speaker 1: these theories has to get torn up basically and start again.
32:23
Speaker 1: And the question is which. And we're hoping that time
32:26
Speaker 1: crystals give us like a glimmer of understanding as to
32:30
Speaker 1: how to begin that process. But even if we knew
32:33
Speaker 1: right for example, that general relativity was correct, doesn't tell
32:36
Speaker 1: us exactly how to start on quantum mechanics, and before
32:39
Speaker 1: we put too many nails in the coffin of quantum mechanics, like,
32:42
Speaker 1: I don't think anybody out there in physics believes general
32:45
Speaker 1: relativity is correct. It's got to be wrong because it
32:48
Speaker 1: assumes that the universe is smooth and continuous in a
32:52
Speaker 1: way that quantum mechanics we know our experiments tell us
32:55
Speaker 1: just can't be true. So my money is on both
32:59
Speaker 1: of them are wrong. And we kind of come up
33:00
Speaker 1: with a whole new theory that combines the two or
33:03
Speaker 1: kind of cross checking these two rule books that were
33:06
Speaker 1: writing based on the quantum information and then the larger
33:11
Speaker 1: scale general relativity information. And it sounds like you physicists
33:16
Speaker 1: have to cross check them and figure out where which
33:19
Speaker 1: things make sense and then kind of get rid of
33:22
Speaker 1: the things that don't as you cross check them, and
33:24
Speaker 1: time crystals might help you do that. Yeah, exactly, And
33:27
Speaker 1: you're right, we're sort of trying to weave these threads together.
33:30
Speaker 1: You know, people have been working on quantum mechanics for
33:31
Speaker 1: a while, people have been working on job relativity for
33:33
Speaker 1: a while, and the goal, of course, is to come
33:36
Speaker 1: up with a single holistic explanation from the whole universe
33:39
Speaker 1: or how everything fits together, and that requires like trying
33:42
Speaker 1: to weave these threats together. And in the past we've succeeded,
33:45
Speaker 1: Like we figured out that electricity and magnetism are really
33:48
Speaker 1: just two sides of the same coin, and neither theory
33:51
Speaker 1: was wrong. They just sort of fit together in an
33:53
Speaker 1: unexpected way. And then we added the weak force, and
33:56
Speaker 1: now we have like a theory of the electromagnetic weak forces.
33:59
Speaker 1: These three things sort of woven together into one common understanding.
34:03
Speaker 1: The goal is to make progress by pulling these things together,
34:06
Speaker 1: by getting our understanding from various bits of physics and
34:08
Speaker 1: sort of putting it together to make a holistic picture.
34:11
Speaker 1: And there's one more part of that thread that we
34:14
Speaker 1: might try to pull in, and this this idea about
34:17
Speaker 1: the connection between time and energy. Right the time crystal,
34:21
Speaker 1: if it exists, is a weird thing because it's in motion,
34:24
Speaker 1: but it's also like at its lowest energy state. Well,
34:27
Speaker 1: there's another deep theorem about physics, Nother's theorem that tells
34:31
Speaker 1: us why we have energy conservation in our universe. It
34:35
Speaker 1: says that energy is conserved in our universe because there's
34:38
Speaker 1: some symmetry with time that the laws of physics should
34:41
Speaker 1: work the same now as they do in ten seconds
34:44
Speaker 1: or in a million years. And we've talked in the
34:46
Speaker 1: program before how we're not actually sure whether energy is
34:49
Speaker 1: conserved because the universe is not actually static in time.
34:52
Speaker 1: It's growing with time, it's expanding. So all these questions
34:56
Speaker 1: are all mixed up in the very nature of time
34:58
Speaker 1: and the meaning of it, and the conservation of energy
35:01
Speaker 1: and general relativity versus quantum mechanics, which is why I
35:03
Speaker 1: was so excited to see experimental tests of time crystals, Like,
35:08
Speaker 1: all right, put the theoretical questions aside, can somebody actually
35:11
Speaker 1: make one of these things? Right? How do you? I mean,
35:14
Speaker 1: it seems like you need really tiny pliers and a
35:17
Speaker 1: really powerful microscope to be able to make a time crystal.
35:22
Speaker 1: How do you go about doing those experiments? So the
35:25
Speaker 1: original idea of this ring of atoms didn't work because
35:28
Speaker 1: people showed that it was not actually in its ground state.
35:31
Speaker 1: But then a bunch of smart people got together and
35:33
Speaker 1: came up with, you know, other ideas, and you're exactly right,
35:36
Speaker 1: you need really tiny pliers. And usually in physics, when
35:39
Speaker 1: we're talking about tiny players were talking about photons, we're
35:42
Speaker 1: talking about like shooting little beams of light at individual
35:45
Speaker 1: atoms to try to make them do something interesting. And
35:48
Speaker 1: so that's exactly what they did here. They put a
35:51
Speaker 1: bunch of atoms together and then they zapped them with lasers.
35:55
Speaker 1: And atoms, you know, have various ways that they can sit.
35:58
Speaker 1: These atoms, for example, have a particular quantum spin. They
36:02
Speaker 1: can spin up or they can spin down. And remember
36:04
Speaker 1: we're not talking about atoms spinning the way like a
36:07
Speaker 1: basketball spins on the tip of your finger. This is
36:09
Speaker 1: some weird quantum mechanical property. And so it either has
36:13
Speaker 1: spin up or it has spin down. It's very difficult
36:16
Speaker 1: for it to be sort of in between. So you
36:18
Speaker 1: arrange a bunch of these atoms in a row, and
36:21
Speaker 1: then the atoms like to either be spin up or
36:23
Speaker 1: spin down, and then you zap them with a laser,
36:26
Speaker 1: which makes those spins flip. I see, so you're zapping them,
36:30
Speaker 1: they have a certain spin preference, and then they start
36:33
Speaker 1: to go the other direction. Yeah, So you have them
36:36
Speaker 1: in some arrangement like the spin up, spin up, spin down,
36:39
Speaker 1: spin up, whatever, and then you zap them with a laser.
36:41
Speaker 1: And the laser is basically just photons, right, This is
36:45
Speaker 1: an oscillating electromagnetic field, and so it can flip the
36:48
Speaker 1: spins because these atoms all have electric charges. So the
36:52
Speaker 1: laser comes in and it can flip the spins in
36:54
Speaker 1: a certain pattern. Because the laser is an electromagnetic field
36:57
Speaker 1: that cannot oscillate up and flip spins up and then
37:00
Speaker 1: as laid down and flip spins down. So what we see,
37:03
Speaker 1: this is super interesting in these experiments, is that they
37:07
Speaker 1: arrange these atoms in a random pattern. The laser comes
37:10
Speaker 1: in and it makes these spins flip. They oscillate, right,
37:13
Speaker 1: you might think, all right, well, that's no big deal,
37:15
Speaker 1: but you're slapping them around exactly, you're slapping them around.
37:18
Speaker 1: But then what happens when you turn off the laser.
37:21
Speaker 1: You turn off the laser and these atoms keep flipping.
37:24
Speaker 1: You keep flipping in exactly the same pattern as when
37:28
Speaker 1: you had the laser on. So they remember how they're
37:32
Speaker 1: supposed to flip, even after the laser that's been smacking
37:36
Speaker 1: them around stops doing that. Exactly, they're in some weird
37:40
Speaker 1: stable configuration where they're in motion and they're returning to
37:44
Speaker 1: the same state over and over again, and they're not
37:47
Speaker 1: just static, right, they're in motion. This is some ground
37:50
Speaker 1: state configuration that's above zero, so it has continuous energy.
37:54
Speaker 1: So how long do they do this? Because you know,
37:57
Speaker 1: someone might think of like that Newton's Cradle office toy
38:01
Speaker 1: where you started going and it goes for a while
38:04
Speaker 1: even without you doing the initial thing, but with the
38:07
Speaker 1: conservation of momentum and eventually breaks down and stops moving.
38:10
Speaker 1: So what happens with these atoms? Yeah, that's a great question,
38:14
Speaker 1: and this is an experimental issue, right. In order to
38:16
Speaker 1: do this, you need to like isolate these atoms, so
38:19
Speaker 1: you need to put them in some sort of larger trap,
38:21
Speaker 1: like use magnets or something to keep the rest of
38:23
Speaker 1: the world from like messing it up. If you were
38:25
Speaker 1: in an empty universe where it's just these atoms and
38:28
Speaker 1: a laser, then we think it could last essentially forever
38:31
Speaker 1: if it really is a time crystal. But it's difficult
38:34
Speaker 1: to keep these things sort of isolated forever. People can
38:37
Speaker 1: do it for minutes at a time, but that's the
38:39
Speaker 1: longest that's been achieved. But we think that's just because
38:42
Speaker 1: of this question of like, you know, isolating it from
38:44
Speaker 1: the universe. We think that probably if it was totally separated,
38:48
Speaker 1: you could just keep going, right, because even in a vacuum,
38:51
Speaker 1: there's not nothingness. There's still stuff going on in that vacuum.
38:54
Speaker 1: Yeah exactly. It's impossible to separate anything from the rest
38:57
Speaker 1: of the universe because there's always like qual fields and
39:00
Speaker 1: fluctuations and all this kind of stuff. And so that's
39:03
Speaker 1: why it's fun to explore these things at a theoretical level,
39:06
Speaker 1: like is this possible? And then it's a totally separate
39:09
Speaker 1: question of like could you actually build these things? One
39:12
Speaker 1: of the experimental obstacles to actually making this existing reality.
39:16
Speaker 1: But there's this team at University of Maryland that put
39:18
Speaker 1: this thing together and it kind of looks like they
39:21
Speaker 1: did it, you know, it kind of looks like the
39:22
Speaker 1: time crystal is real. That's so interesting. So this proof
39:26
Speaker 1: of concept by being able to create these oscillating atoms
39:31
Speaker 1: that you smack once and they're like all right, I
39:33
Speaker 1: get it, I get it. I'll keep doing that, and
39:36
Speaker 1: then you can use that information to maybe do more
39:40
Speaker 1: work sort of in terms of like theoretical physics. Yeah exactly,
39:44
Speaker 1: And that gives us some like understanding of you know,
39:47
Speaker 1: what is the nature of time? Now that we know
39:49
Speaker 1: that time crystals. We think the time crystals are a reality.
39:53
Speaker 1: We can go back and use that to like help
39:56
Speaker 1: guide us in building a deeper, more fundamental theory of
39:59
Speaker 1: like quantum gravity that has the right respect for time,
40:03
Speaker 1: that treats time more like an element of space time.
40:06
Speaker 1: We think that the existence of time crystals points in
40:09
Speaker 1: the direction that the general relativity concept of time is correct.
40:13
Speaker 1: That doesn't mean that general relativities are right about everything
40:16
Speaker 1: we know. It breaks down as singularities, but this basic
40:19
Speaker 1: concept that space and time are deeply interwoven is more
40:22
Speaker 1: likely to be true because time crystals exist. Right, Maybe
40:26
Speaker 1: we're seeing a little more agreement between quantum mechanics and
40:30
Speaker 1: general relativity than there was before. Can't we all just
40:33
Speaker 1: get along? Community? Right? Community is the name of the day,
40:38
Speaker 1: And also it's fun experimentally, like this is a really
40:41
Speaker 1: important thing that might actually be useful technologically, imagine like
40:45
Speaker 1: storing information. One thing that's difficult about building quantum computers
40:50
Speaker 1: is that it's hard for them to have memories because
40:52
Speaker 1: quantum objects these tiny little particles. They often like decay
40:56
Speaker 1: and they don't last very long in the state that
40:58
Speaker 1: you want. Well, time crystals might be a gray way
41:01
Speaker 1: to build memory circuits for quantum computers because they are
41:05
Speaker 1: stable in their lowest state and sort of remember the
41:08
Speaker 1: configuration that you put them in. The pattern that you
41:11
Speaker 1: put them in lasts through time. This is great for
41:14
Speaker 1: our quantum hamster script because now we can get teeny
41:17
Speaker 1: tiny computers for teeny tiny quantum hamsters. So that whole
41:22
Speaker 1: scene where they're breaking into the quantum mainframe, that's gonna work.
41:26
Speaker 1: Feeling good about this? Are they powered by tiny little
41:30
Speaker 1: quantum cotton candies? That what gives the quantum hamster its power.
41:33
Speaker 1: I mean, they got to keep up their carbs so
41:35
Speaker 1: they can run in those tiny quantum wheels, keeping going.
41:38
Speaker 1: Or maybe they should eat like scalloped crystal eyeballs. Now
41:43
Speaker 1: we're getting into a horror movie. Oh yeah, that's right.
41:47
Speaker 1: That's the Dark TV spinoff that will will sell after
41:50
Speaker 1: the future. So this team in Maryland did this, and
41:53
Speaker 1: then there's a team at Harvard that did something different.
41:56
Speaker 1: They took a diamond, right, which is a space crystal,
41:59
Speaker 1: and they put a bunch of nitrogen atoms inside that
42:01
Speaker 1: diamond and then they turned those nitrogen atoms into a
42:05
Speaker 1: time crystal by zapping it with a laser in a
42:07
Speaker 1: very similar way. That's truly got to be a girl's
42:10
Speaker 1: best friend. A diamond, and inside the diamond is a
42:14
Speaker 1: time diamond. Yeah, exactly, a time diamond inside a space diamond.
42:19
Speaker 1: That or it's like the taco bell version, you know,
42:22
Speaker 1: take a burrito and wrap it in a taco and
42:24
Speaker 1: then dip the whole thing in cheese. Either would be
42:26
Speaker 1: good engagement gaps, I think exactly. So it's a really
42:32
Speaker 1: exciting time sort of theoretically, like is this possible? There
42:36
Speaker 1: was a lot of discussion. People fought for many years
42:39
Speaker 1: that this was totally impossible. All the theorem suggested couldn't
42:42
Speaker 1: be done, and then people found few loopholes, and then
42:44
Speaker 1: a bunch of experimentalists when out there, said hey, we're
42:47
Speaker 1: just gonna try to make this thing, and it looks
42:48
Speaker 1: like they might have. So it's really fun for me
42:51
Speaker 1: to see like a whole area of signs that people
42:54
Speaker 1: didn't even consider as possible suddenly explode with activity and
42:58
Speaker 1: ideas and in vation. That's the great thing about sciences.
43:02
Speaker 1: You're always finding new things. Like you take old information,
43:08
Speaker 1: you shake it up, and you find new things you
43:10
Speaker 1: previously thought was impossible and now when I'm late to
43:13
Speaker 1: an appointment, I can say, well, have you heard the
43:15
Speaker 1: news about time crystals? Our whole concept of time might
43:18
Speaker 1: not be right. That's right. Maybe I'm not late, maybe
43:21
Speaker 1: you're late to Daniel says time can't be eternal. Anyway,
43:28
Speaker 1: I've got a note from my physicist who says it's okay.
43:32
Speaker 1: The larger motivation is that there are still really basic
43:36
Speaker 1: questions out there, really big puzzles that haven't been solved
43:40
Speaker 1: because nobody asked the right question or had the right
43:42
Speaker 1: first idea. And so Frank Wilcheck is a little cookie,
43:46
Speaker 1: but I love that he goes out there and tries
43:48
Speaker 1: to tackle something that people think is impossible and actually
43:50
Speaker 1: makes progress and makes a mistake, but along the way,
43:54
Speaker 1: you know, breaks open a whole area of research. And
43:57
Speaker 1: so somebody out there listening, hoping to grow up to
43:59
Speaker 1: be a is just to make some big discovery. Don't
44:02
Speaker 1: think that we figured it all out. We are far
44:04
Speaker 1: from understanding the nature of the universe around us. There
44:07
Speaker 1: are lots of really basic questions out there for you
44:10
Speaker 1: to find the answers to. And if you're too afraid
44:13
Speaker 1: to ask a question because you think it will be
44:15
Speaker 1: stupid or wrong, you may never open up some really
44:18
Speaker 1: interesting research avenues. Yeah, exactly, and remember even Nobel Prize
44:23
Speaker 1: winners make mistakes. Take that Nobel Prize winner is not
44:26
Speaker 1: so fancy now, are we? Well? Thank you guys so
44:32
Speaker 1: much for listening. I hope you enjoyed our little time
44:35
Speaker 1: Crystal time, and we will see you next time time
44:39
Speaker 1: Crystal or not, we don't know, it's hard to say.
44:42
Speaker 1: All right, thanks for listening everyone, Thanks for listening, and
44:52
Speaker 1: remember that Daniel and Jorge Explain the Universe is a
44:55
Speaker 1: production of My Heart Radio for More podcast for my
44:59
Speaker 1: Heart Radio at the I Heart Radio app, Apple Podcasts,
45:02
Speaker 1: or wherever you listen to your favorite shows. H