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Is the Universe Random? · Daniel and Kelly’s Extraordinary Universe

0:07
Speaker 1: There's a core idea in science that experiments should be repeatable.
0:12
Speaker 1: If you do an experiment the same way at different times,
0:14
Speaker 1: you should get the same result. However, there is a loophole.
0:19
Speaker 1: There's a loophole in science. Yeah, and that loophole opens
0:24
Speaker 1: a window into everything we think is true about reality
0:28
Speaker 1: and the universe and everything. Doo doo doo doo doo
0:32
Speaker 1: doo doo doo doo doo doo. Welcome to Daniel and
0:50
Speaker 1: Jorge explain the Universe, in which we try to take
0:52
Speaker 1: the entire universe and break it into bite sized pieces
0:56
Speaker 1: so you're gonna enjoy them with your afternoon coffee. I'm alright.
0:58
Speaker 1: I'm a cartoonist. I draw comics online, and I'm Daniel.
1:02
Speaker 1: I'm a particle physicist. I spend my days smashing protons
1:05
Speaker 1: together at the Large Hadron Collider to try to reveal
1:08
Speaker 1: the secrets of the universe, mostly so that I can
1:11
Speaker 1: tell them to you in this podcast. Basically only one
1:14
Speaker 1: of us is qualified to be explaining things to you
1:17
Speaker 1: on this podcast. That would be the cartoonist business. They're
1:21
Speaker 1: not qualified usually to be explainers. Mostly we just try
1:23
Speaker 1: to solve the mysteries of the universe. We don't try
1:25
Speaker 1: to tell anybody about them, right, Mostly physicists just need explaining,
1:30
Speaker 1: that's right, that's where the cartoons come in, right, And
1:33
Speaker 1: spouses also, spouses physicist probably have to do a lot
1:37
Speaker 1: of explaining. You've got some explaining to do, exactly. Yeah. Um,
1:41
Speaker 1: So we're here to talk to you about big questions
1:43
Speaker 1: about the universe. And today's question is a really deep
1:46
Speaker 1: and basic question, and it's about the very nature of reality.
1:50
Speaker 1: What is it? Hory? What are we gonna talk about today?
1:54
Speaker 1: Is the universe random or is it just chaotic? And
1:59
Speaker 1: what the difference? Or is it run by some super being?
2:03
Speaker 1: And we're actually just in their simulation. But that's a
2:06
Speaker 1: whole other episode. That's a whole other podcast. Right today,
2:09
Speaker 1: just the two sinister options, random or chaotic, you might
2:12
Speaker 1: feel like, oh, neither of those sound very cozy. I
2:14
Speaker 1: don't want to live in either of those universes. Well,
2:17
Speaker 1: the question basically breaks down to is the universe predictable?
2:21
Speaker 1: Like can you predict what the universe is going to do?
2:23
Speaker 1: Or is it that nobody can predict what the universe
2:27
Speaker 1: is going to do? Right? And I think that's why
2:28
Speaker 1: It's an awesome question for science because for so many
2:32
Speaker 1: thousands and thousands of years, I think humans probably felt
2:36
Speaker 1: like the universe around them was totally unpredictable. I mean,
2:39
Speaker 1: they invented gods for this and for that to try
2:41
Speaker 1: to describe how the universe was out of their control
2:44
Speaker 1: and doing things that didn't make sense, as if it
2:46
Speaker 1: had some you will and agency. Right, and then science
2:49
Speaker 1: comes along it says, actually, there are rules and you
2:52
Speaker 1: can discover them. And slowly science starts to creep in
2:56
Speaker 1: this description of the universe that locks out this agency,
2:59
Speaker 1: this idea of this personality, and gives you the sense
3:02
Speaker 1: that maybe the universe follows these rules. Right. So we
3:05
Speaker 1: went out and as usually, ask people on the street,
3:08
Speaker 1: do you think the universe is random or chaotic? And
3:13
Speaker 1: here's what they had to say, that's gonna okay, that's
3:16
Speaker 1: a that's a thinker right there. I would say truly random.
3:21
Speaker 1: With randomness comes chaos. You never know what I what
3:24
Speaker 1: will happen, but there's there's always a probability and a
3:28
Speaker 1: chance of things, of certain things happening. I'd like to
3:31
Speaker 1: say random. I'm religious, so I feel like everything happens
3:35
Speaker 1: for a reason. And yes it is random, but there's
3:38
Speaker 1: a purpose behind everything. I think it's a mixture of both,
3:42
Speaker 1: like like it's random, but it can appear chaotic because
3:46
Speaker 1: of how everything is truly chaotic, because like on a
3:51
Speaker 1: smaller level, everything is like moving really fast, but at
3:55
Speaker 1: like a bigger level, we we don't see any of that. Wow,
4:00
Speaker 1: So what do you think of those answers for I
4:02
Speaker 1: think they were all over the place. They were actually,
4:05
Speaker 1: um kind of random. They were random and chaotic. I
4:08
Speaker 1: feel like I feel like people had no idea what
4:11
Speaker 1: I was asking them. You know, I feel like people
4:14
Speaker 1: just I feel like they had no idea what they
4:15
Speaker 1: were answering. You know, some of those people I remember
4:19
Speaker 1: recording these interviews, and some of those people, as the
4:21
Speaker 1: words were coming out of their mouth, I felt like
4:23
Speaker 1: they surprised them as much as they did me. Like
4:25
Speaker 1: it was all over the place. Yeah, well, I feel
4:28
Speaker 1: like some people it's interesting. Some people related to the
4:30
Speaker 1: question that question to the other question, which is like
4:33
Speaker 1: does the universe have a purpose, Like do things happen
4:36
Speaker 1: for a reason or do they is it just like
4:39
Speaker 1: a random role to die and nobody is really in charge?
4:42
Speaker 1: Like that's the question, right, like, is somebody in charge
4:44
Speaker 1: of the universe or is it impossible for anyone to
4:48
Speaker 1: kind of predict what it's going to do. Yeah, I
4:49
Speaker 1: think you're right. That does get at the heart of
4:51
Speaker 1: the question. You know, what's going to happen in the
4:53
Speaker 1: universe and can we tell and can we influence it? Right?
4:57
Speaker 1: Is the universe sort of churning on without our ability
4:59
Speaker 1: to change direction at all in some sort of way
5:02
Speaker 1: that's been determined since the dawn of time? Or can
5:05
Speaker 1: we nudge it and push it in one way or
5:06
Speaker 1: the other? You know, make the calves a win? Or
5:08
Speaker 1: can you if you jump up and down in front
5:10
Speaker 1: of your television enough where the Warriors win another NBA championship?
5:13
Speaker 1: You know, can you influence the world? I think that's
5:15
Speaker 1: a that's an interesting and deep question. Yeah, that's probably
5:18
Speaker 1: the one people were actually having in their mind. Yeah,
5:21
Speaker 1: so maybe let's go back in history, and I like
5:23
Speaker 1: how you think about this question a lot, Daniel, which
5:27
Speaker 1: is that you sort of start with early man like
5:29
Speaker 1: the cavemen and women and women early humans. Um, we're
5:33
Speaker 1: really just kind of at the mercy of all the
5:35
Speaker 1: elements and all the animals out there, and the weather
5:38
Speaker 1: and so they to them, the universe was this crazy,
5:41
Speaker 1: random and chaotic place, right, Yeah, And it actually touches
5:44
Speaker 1: on sort of my personal theory of consciousness, which is
5:47
Speaker 1: that we developed this awareness because we are looking out
5:51
Speaker 1: into the world for other people or other ideas, are
5:54
Speaker 1: their intelligences, and we have this hyperactive ability to see agency,
5:58
Speaker 1: to see intention in something that we don't understand, and
6:01
Speaker 1: we imagine that there must be a mind behind it.
6:04
Speaker 1: And so I think for a long time people's view
6:05
Speaker 1: the world was that it was controlled by other greater minds.
6:09
Speaker 1: You know, what controls the lightning? Why do some people
6:12
Speaker 1: die of disease? All this stuff? And then as there
6:14
Speaker 1: must be like a consciousness that is shooting out these
6:18
Speaker 1: lightning bolts or making it rain, or you know, making
6:22
Speaker 1: the sun come out, or killing my baby of some
6:24
Speaker 1: horrible disease, right, like, there must be. It's hard to
6:27
Speaker 1: live in this world if you don't have the sense
6:29
Speaker 1: that there's somebody else in charge. Right There's a lot
6:32
Speaker 1: of suffering and a lot of pain, and a lot
6:34
Speaker 1: of unexplained events, and it's nice to think somebody else
6:38
Speaker 1: out there is taking care of it, or somebody's in
6:40
Speaker 1: charge of it. But there's a reason, right yeah, that
6:42
Speaker 1: there's a reason, that there's some design, it's not just random. Um.
6:46
Speaker 1: But then as history progresses that we were saying earlier,
6:49
Speaker 1: you know, sigence comes along and says, well, there are
6:51
Speaker 1: seemed to be some rules, not just like that anything
6:54
Speaker 1: can happen. You can't have an ostrich here and then
6:57
Speaker 1: all of a sudden the ostrich is gone. There are
6:58
Speaker 1: some rules that limit what can happen. If you know
7:01
Speaker 1: what's happening now, there's a certain set of possibilities for
7:04
Speaker 1: what can happen in one second, in two seconds. And
7:06
Speaker 1: you know that's physics, right Well, it's it's started with
7:09
Speaker 1: like noticing patterns, right Like lightning doesn't just come out
7:12
Speaker 1: of nowhere, it comes out when there's these dark clouds
7:16
Speaker 1: in the sky, right yeah, absolutely absolutely, And people started
7:19
Speaker 1: noticing patterns and started putting those together and then asking themselves,
7:23
Speaker 1: can I use what I've learned in the past to
7:26
Speaker 1: predict the future? Right Like, if I have the same
7:29
Speaker 1: set of events that happened yesterday, am I gonna be
7:32
Speaker 1: able to tell what's going to happen next week? If
7:33
Speaker 1: the same thing happens, If I roll a ball down
7:36
Speaker 1: the hill yesterday and it goes up to a certain speed,
7:38
Speaker 1: Will the same thing happened tomorrow? Right? Right? Or if
7:41
Speaker 1: I throw a ball in the air and I know
7:43
Speaker 1: which direction it's going and how fast it is going,
7:46
Speaker 1: can I predict where it's gonna land exactly? If I
7:48
Speaker 1: build a catapult, can I basically aim it right exactly?
7:51
Speaker 1: And that's how military technology drove science even hundreds of
7:55
Speaker 1: years ago. Right, Where do I shoot my cannon exactly
7:58
Speaker 1: to get over that wall? Well, that's kind of where
8:01
Speaker 1: um Newton came in, right, Isaac Newton, And that's why
8:03
Speaker 1: they say he kind of gave birth to science, right,
8:07
Speaker 1: or at least the scientific Revolution. No, I think it
8:09
Speaker 1: was earlier than that. Newton came along well after folks
8:12
Speaker 1: like Galileo and and Francis Bacon and those guys. They
8:17
Speaker 1: really were the first ones to do experiments and to say,
8:20
Speaker 1: let's see what the rules the universe is following, and
8:22
Speaker 1: let's see if we can try to deduce them and
8:24
Speaker 1: use those to predict the outcome of future experiments. They're
8:27
Speaker 1: really were the first ones to connect the idea of
8:29
Speaker 1: a scientific universe to the actual experiments they do to
8:32
Speaker 1: influence those ideas and to predict future results. And I
8:36
Speaker 1: think that's the key is that here we've developed a
8:38
Speaker 1: system science which cannot only explain what we've seen before,
8:42
Speaker 1: but can predict the future. And you are about to
8:45
Speaker 1: fire a cannonball at your enemy, you want to know
8:47
Speaker 1: where is that ball going to fly? And it's incredible
8:50
Speaker 1: that physics can do that. It can literally predict the
8:53
Speaker 1: future if you know enough about the situation right right,
8:56
Speaker 1: It's kind of like Google Maps. Now I can totally
8:58
Speaker 1: tell if you're going to be late to the meeting
9:00
Speaker 1: or not, or to a podcast recording they're gonna They're like, like,
9:04
Speaker 1: how long will they need to get home? They're like,
9:06
Speaker 1: they're gonna be late. It's not always a hard problem though. Joe.
9:09
Speaker 1: For example, it says if person equals Jorge, then late
9:12
Speaker 1: equals true every time, every time. A lot of data,
9:19
Speaker 1: and some of these things are simple, but some of
9:24
Speaker 1: these things are complicated, and it's incredible to witness as
9:27
Speaker 1: physics sort of builds confidence and science develops our ability
9:31
Speaker 1: to predict you know, chemical reactions and biological functioning, all
9:35
Speaker 1: sorts of things, and then it gives this creeping sense
9:38
Speaker 1: of is there anything that can escape science, Right, Can
9:41
Speaker 1: science predict everything? Like, if you knew enough about the world,
9:45
Speaker 1: could you break it all down to cannonballs to predict
9:48
Speaker 1: where all those cannonballs are going to fly and then
9:50
Speaker 1: tell exactly what's going to happen. Yeah, And it's it's
9:52
Speaker 1: like kind of like if you know that force equals
9:54
Speaker 1: mass science acceleration, like Needton figured out, um, then you
10:00
Speaker 1: can predict things like cannonballs and catapults and and and
10:03
Speaker 1: you could possibly predict like how a room full of
10:06
Speaker 1: particles move, right, Yeah, possibly you can extend that to
10:10
Speaker 1: can you predict how, um the whole world works? Yeah,
10:15
Speaker 1: what it's going to do and what people are going
10:16
Speaker 1: to do? Extrapolate to the whole universe, right, I mean,
10:19
Speaker 1: and that's the principle of determinism. It says, Look, if
10:22
Speaker 1: things follow rules, and the future is dependent only two things,
10:26
Speaker 1: one the rules and two the things that are happening
10:29
Speaker 1: now the current state. Right, given that if you know
10:32
Speaker 1: exactly where things are, imagine the whole universe is just
10:35
Speaker 1: a bunch of tiny cannonballs, and you know the rules
10:37
Speaker 1: of those cannonballs, and you know the position and direction
10:39
Speaker 1: of motion of all those cannonballs. Then in principle, given
10:43
Speaker 1: a super powerful universe sized computer, you should be able
10:46
Speaker 1: to predict the future one to five ten seconds into
10:49
Speaker 1: the future, a thousand seconds into the future, like every
10:52
Speaker 1: single molecule, atoms of atomic particle. You should be able
10:55
Speaker 1: if it follows rules, you should be able to kind
10:58
Speaker 1: of track where it's going to go if you tell
11:00
Speaker 1: you based on where things are now, what's going to happen? Exactly.
11:04
Speaker 1: It's kind of like this idea of a clock, right,
11:06
Speaker 1: is the universe giant clock just kind of clicking along
11:10
Speaker 1: or is there some kind of magic inside of it
11:13
Speaker 1: that makes it unpredictable? Right exactly? And the idea of
11:17
Speaker 1: the universe just being a huge clock, is both exciting
11:20
Speaker 1: and terrifying. Right. It's exciting because like, wow, can you
11:23
Speaker 1: imagine we could understand the universe that well, that we
11:25
Speaker 1: could predict the future, think about what we could do, right,
11:28
Speaker 1: But it's terrifying because it's sort of like you're trapped
11:31
Speaker 1: in this science cage where you have no influence over
11:34
Speaker 1: the world and everything you do and know and say,
11:36
Speaker 1: and that joke you're going to make in that fart
11:38
Speaker 1: you're gonna let slip are all predictable? Right, all those
11:41
Speaker 1: things are predictable. That's scary. It makes you feel like
11:44
Speaker 1: you are part of that watch and you're just clicking
11:46
Speaker 1: along because of the the you're reacting to things around
11:49
Speaker 1: you and your initial conditions, and so that's terrifying. And
11:52
Speaker 1: I think we have kind of in anate sense of
11:55
Speaker 1: like rejecting this idea that we're trapped, right we everyone
11:58
Speaker 1: wants to feel like they have free will, like everyone
12:01
Speaker 1: wants to know that they have a choice, right. Well,
12:03
Speaker 1: I guess so my kids don't feel that way, you know,
12:05
Speaker 1: like why did you hit your sister? Well she hit me,
12:08
Speaker 1: you know, like, well, so what you have no free will?
12:10
Speaker 1: Like you're completely determined by her behavior. Um. I have
12:13
Speaker 1: that argument with my kids so many times. I'm always
12:16
Speaker 1: thinking about the philosophical echoes of that. Um. Um, My
12:20
Speaker 1: kids are always rebelling. They're like, we want free will,
12:23
Speaker 1: don't tell us what to do, but they want you
12:26
Speaker 1: to follow rules. They're like, you promised daddy we could
12:28
Speaker 1: have ice cream, right, and so therefore you have to
12:31
Speaker 1: there's no more decision to be made. Kids are so
12:33
Speaker 1: unfair there, philosophically inconsistent. I think it's really the problem
12:38
Speaker 1: with kids Yeah, they're cute, but if they just read
12:43
Speaker 1: some more nice you know, and some some carl and
12:46
Speaker 1: some paper or whatever, they would be easier to be around. Yeah,
12:49
Speaker 1: forget those picture books. Let's introduce let's predict the universe.
13:07
Speaker 1: I think there's something fascinating about the deterministic view of
13:09
Speaker 1: the universe. But probably people out there thinking, Okay, maybe
13:13
Speaker 1: in theory you could predict the whole universe, but in
13:15
Speaker 1: practice that's impossible. I mean, you don't have a universe
13:18
Speaker 1: sized computer to break the whole universe, and even to
13:21
Speaker 1: predict like you know, a person is a huge number
13:24
Speaker 1: of articles, and so to do that calculation just seems impractical, right, right,
13:29
Speaker 1: It's practically impossible. But I think people reveled just to
13:32
Speaker 1: the idea of it, right, Like, are my thoughts my
13:35
Speaker 1: thoughts or just something that I'm programmed and that I
13:39
Speaker 1: will inevitably have and do. Yeah, and that's a really
13:42
Speaker 1: deep question. And so um, we started out with prehistoric
13:46
Speaker 1: man feeling like the universe is full of random of
13:48
Speaker 1: not random, but unexplained agency and intelligence all the way
13:52
Speaker 1: to like now, scientific physical determinism says, actually the universe
13:57
Speaker 1: just clicks along like a watch, right, and there's no
13:59
Speaker 1: free will. So let's take one step back from that,
14:02
Speaker 1: and that's chaos. That says, well, maybe the universe is deterministic, sure,
14:07
Speaker 1: but that doesn't mean it's necessarily practical for you to
14:10
Speaker 1: predict it because the way things play out is really
14:13
Speaker 1: sensitive to exactly how things started. Well, I think I
14:17
Speaker 1: think some people who responded to their question maybe weren't
14:20
Speaker 1: sure about the difference, right, Like, what's the difference between
14:22
Speaker 1: something being chaotic and something being random? Right? And so
14:26
Speaker 1: let's drill into that. So let's take, for an example,
14:29
Speaker 1: the roll of a dice. Right, people think of rolling
14:32
Speaker 1: dice is random, but actually it's chaotic, meaning that it's
14:35
Speaker 1: hard to predict, but it is deterministic. What do you
14:39
Speaker 1: mean if you knew exactly how I threw the dice,
14:42
Speaker 1: like exactly the direction and the spin and all the
14:45
Speaker 1: molecules of the air, then you could treat the molec
14:47
Speaker 1: little cannonballs, little particles, and you could model how it rolls,
14:51
Speaker 1: and you could, in theory, predict exactly how the dice
14:53
Speaker 1: rolled every time, meaning like if I if i'm if
14:56
Speaker 1: I'm seeing footage of you throwing to die, and like
14:58
Speaker 1: like I pause the video just as to die leave
15:02
Speaker 1: your hands, then I could you know know where they are,
15:06
Speaker 1: I know which direction are going, how fast are going.
15:08
Speaker 1: I could run some kind of computer simulation to like
15:12
Speaker 1: follow the die and predict what they're going to do
15:14
Speaker 1: when they bounce off the table on roll around, I
15:17
Speaker 1: could potentially predict what the die are going to show.
15:20
Speaker 1: That's right, because we're saying that the universe in that
15:23
Speaker 1: case is deterministic, and so you should be able to
15:25
Speaker 1: predict the future given enough information about the setup. Right now,
15:29
Speaker 1: that's a hard problem, and that's why we use dies, right,
15:32
Speaker 1: because it's really difficult, and nobody can practically like bring
15:36
Speaker 1: a mini computer into Las Vegas and use that to
15:38
Speaker 1: predict who's going to win it craps, right though, in theory,
15:42
Speaker 1: In theory, you could if the universe was deterministic but
15:45
Speaker 1: very sensitive to exactly how somebody's rolling the dice. Right
15:49
Speaker 1: when you throw the dice of craps, if you flip
15:51
Speaker 1: it this way or that way, then it's going to
15:53
Speaker 1: bounce slightly differently, and how it's going to hit that
15:55
Speaker 1: you know, the felt on the table. It's all very
15:57
Speaker 1: very sensitive and a very small change how you throw
16:00
Speaker 1: it can result in a totally different number. That's what
16:03
Speaker 1: we mean by chaos. It means that it's like that
16:06
Speaker 1: the butterfly effect, right, like the idea that if you
16:09
Speaker 1: butterfly flaps its wing here, it's going to have a
16:12
Speaker 1: huge effect, maybe potentially on the weather and on the
16:15
Speaker 1: other side of the world. Right, it's like a very
16:17
Speaker 1: sensitive system. That's right. The weather is a great example
16:20
Speaker 1: because we understand all the processes of weather. I mean,
16:23
Speaker 1: it's hot air, it's cold air, it's water. We know
16:25
Speaker 1: that stuff. It's pretty simple chemistry. But altogether, an entire
16:28
Speaker 1: planet is really difficult to describe because it's huge and
16:32
Speaker 1: it's really sensitive. Like, as you say, a butterfly flapping
16:35
Speaker 1: its wings in China could change the way this air flows,
16:38
Speaker 1: which could change the way that air flows, which bounces
16:41
Speaker 1: off this building, which turns into a rainstorm, which collides
16:43
Speaker 1: with this cloud and causes a hurricane. Right, it's not
16:46
Speaker 1: true that every time a butterfly flaps its wings you
16:48
Speaker 1: get a hurricane. But sometimes so. Weather is chaotic, but
16:54
Speaker 1: it's not random, is that what you're saying? That ran like,
16:56
Speaker 1: if we could keep track of every single butterfly in
16:59
Speaker 1: the world flapping its wing. We would be able to
17:02
Speaker 1: predict the weather if we had a giant supercomputer the
17:05
Speaker 1: size of the Solar System. But since we don't, then
17:09
Speaker 1: weather it seems random, but actually it's chaotic exactly, And
17:13
Speaker 1: that's exactly what scientists are trying to do. They're building
17:16
Speaker 1: bigger and bigger and faster computers to try to simulate
17:19
Speaker 1: more and more of the Earth's atmosphere to get better
17:21
Speaker 1: and better predictions of weather. In fact, I think like
17:24
Speaker 1: all the top ten supercomputers in the world are devoted
17:27
Speaker 1: to that problem, like modeling the weather, because it's important.
17:30
Speaker 1: But you're exactly right, it's actually chaotic, meaning it's deterministic
17:34
Speaker 1: but really sensitive to exactly how it started. But it
17:36
Speaker 1: seems random because it's it's too difficult for us to calculate.
17:40
Speaker 1: In principle, we should be able to, but we can't.
17:42
Speaker 1: Another example is flipping a coin. Right, based on how
17:46
Speaker 1: you flip the coin, you should be able to model
17:48
Speaker 1: how it spins through the air and how it bounces
17:49
Speaker 1: off air molecule and how it hits the ground and
17:51
Speaker 1: where it lands. But it's a difficult problem. So we
17:54
Speaker 1: can use it to model randomness to say it's kind
17:57
Speaker 1: of like randomness. Really it's just chaotic though. But then
18:00
Speaker 1: if I flip the coin a hundred times, most likely
18:05
Speaker 1: half of those times will be head and half of
18:07
Speaker 1: those times will be tails. Right, So where does that
18:10
Speaker 1: fit into chaos theory? Like why is it predictable on
18:13
Speaker 1: a statistical basis? Okay, so that's fascinating. That's an emergent phenomenon. Right.
18:18
Speaker 1: That says if you understand the tiny little local laws
18:22
Speaker 1: of physics, like the laws of how the particles inside
18:25
Speaker 1: the coin move, you should be able to predict some
18:27
Speaker 1: larger effect. And it's true, there is a simple or
18:30
Speaker 1: description of that larger effect, right, if you understand how
18:33
Speaker 1: these things work. Um, So physics works on these layers. Right.
18:36
Speaker 1: You can either understand it a very low layer and
18:38
Speaker 1: try to model it all the way up to a
18:40
Speaker 1: higher layer, or you can just try to get an
18:42
Speaker 1: understanding of at a higher layer, just the same way.
18:46
Speaker 1: You could say, well, I can understand the way cannonball
18:48
Speaker 1: flies by modeling all the particles inside of it, or
18:51
Speaker 1: you could just use F equals m A, which treats
18:53
Speaker 1: the whole cannonball like one particle. If that's just a
18:56
Speaker 1: question of at what layer you're modeling something, right, Okay,
19:00
Speaker 1: so a coin is chaotic but not actually random, but
19:04
Speaker 1: not actually random. Yet, if the universe is deterministic, then
19:07
Speaker 1: a coin is chaotic but not actually random. Yeah, okay,
19:11
Speaker 1: got it, got it. But then it's the question of
19:13
Speaker 1: that's the really the nugget of the question is is
19:16
Speaker 1: the universe deterministic? Um, you know, if you have a
19:19
Speaker 1: particle or a billiard ball or cannonball or whatever, and
19:22
Speaker 1: you understand direction it's going, can you predict its future
19:25
Speaker 1: out into infinity? Right? Right? You tell exactly what's going
19:29
Speaker 1: to happen. But there's so many factors leading up to
19:32
Speaker 1: me tossing the coin that it's so unpredictable that it's
19:35
Speaker 1: it's it feels random, that's right. And so we have
19:38
Speaker 1: to separate between what's practical and what's in theory possible.
19:42
Speaker 1: Anything that's chaotic. We're saying, in theory, if you knew enough,
19:45
Speaker 1: you could predict it, right, whereas but in practice that
19:49
Speaker 1: we can't. So it's it's it's can't. So it seems random.
19:53
Speaker 1: Random number generators and computers when they try to come
19:56
Speaker 1: up with a random number, it's not really random. You're
19:58
Speaker 1: saying it's just an algorithm. That's very that's chaotic. That's right.
20:02
Speaker 1: Computers by construction are deterministic, right, We've built them to
20:05
Speaker 1: be deterministic. Every time you run a program, it should
20:08
Speaker 1: give you the same answer if you give it the
20:10
Speaker 1: same input. Right. That's there's no way for computer to
20:13
Speaker 1: do anything but that. It's like a series of logic gates.
20:16
Speaker 1: And you know, how it's implemented is not important, but
20:19
Speaker 1: you know it's a system for doing deterministic calculations. That's
20:22
Speaker 1: what a computer is. So it's impossible for computer to
20:25
Speaker 1: be truly random. All the random number generators in your
20:28
Speaker 1: favorite Python code are actually pseudo random number generators. They're
20:32
Speaker 1: just chaotic. They take a seed a number to start from,
20:36
Speaker 1: and then they spin off of that and generate a
20:38
Speaker 1: sequence of numbers. But if you give them the same
20:40
Speaker 1: seed twice, they'll generate the same sequence of numbers twice. Wow.
20:44
Speaker 1: So like if you're playing a video game and you're
20:46
Speaker 1: inside of a virtual world, that world is totally determinating.
20:50
Speaker 1: It's being crunched on by a logical computer. Exactly. You
20:53
Speaker 1: do the same move every time. You'll kill that boss
20:56
Speaker 1: character every single time, and not even in silivating games
20:59
Speaker 1: like you know, like punch Out where the guy is
21:01
Speaker 1: totally predictable, but even the more complicated ones. You know, Um,
21:05
Speaker 1: if you're in the same world and you do the
21:06
Speaker 1: same thing, the same thing should happen, because computers are
21:08
Speaker 1: not capable of true randomness. Before we keep going, let's
21:12
Speaker 1: take a short break. So the question is is our
21:27
Speaker 1: universe like a computer simulation? Right? Like the question is
21:32
Speaker 1: is is our universe also being crunched by a logical
21:36
Speaker 1: computer that can't be random? That's right? And for a
21:39
Speaker 1: long time people thought the universe was deterministic. I mean,
21:42
Speaker 1: we were able to predict the outcome of every experiment. Um,
21:45
Speaker 1: things were going along really well. And then of course
21:47
Speaker 1: and throw a spaceship and landed on the moon. That's
21:50
Speaker 1: pretty crazy, right, Yeah, that well that's pretty risky, but yeah,
21:53
Speaker 1: um that's pretty amazing. You have to certainly have confidence
21:55
Speaker 1: in our ability to predict the future if you're gonna
21:57
Speaker 1: get into that can involve gets shot out into space. Right. Um, Well,
22:02
Speaker 1: I remember in grad schlos in this classic it's called
22:05
Speaker 1: linear dynamical systems. But I remember in class, this guy
22:08
Speaker 1: was so the professor was so cocky. He's like, of
22:10
Speaker 1: while the technologies that contributed to putting a man on
22:13
Speaker 1: the moon, this is the one that made it happen
22:17
Speaker 1: linear algebra. Kind of had this linear algebra equation, we
22:20
Speaker 1: would not be able to put a man in And
22:22
Speaker 1: so that that's how powerful this idea is, right, Like,
22:24
Speaker 1: if you can predict efreequels in a you can put
22:27
Speaker 1: a man on the moon. Yeah. No, it's exactly right,
22:29
Speaker 1: And it's given us great power over our environment. I mean,
22:32
Speaker 1: everything that we have is because we have mastered a
22:35
Speaker 1: lot of the laws of our environment and use them
22:37
Speaker 1: and bent them to our will to improve our lives. Right,
22:40
Speaker 1: So it certainly works, and we rely on every day,
22:42
Speaker 1: every time you get into a car or an airplane,
22:44
Speaker 1: you rely on it working the same way it did yesterday, right, right, right,
22:48
Speaker 1: So that's that's a relief. Um. But it was about
22:50
Speaker 1: a hundred years ago when people started seeing things that
22:53
Speaker 1: they couldn't explain, and it was quantum mechanics that told
22:56
Speaker 1: us that maybe the universe is not deterministic. Maybe these
23:00
Speaker 1: little particles don't follow the same rules that like billiard
23:04
Speaker 1: balls and basketballs and larger objects follow, and maybe they're
23:08
Speaker 1: not even deterministic. Meaning if you do the same experiment
23:11
Speaker 1: twice with tiny particles, you could get different outcomes even
23:15
Speaker 1: if you do it exactly the same way. Well, and
23:18
Speaker 1: this all came about when people started noticing that like
23:20
Speaker 1: light and things had a minimum size, right, Like light
23:25
Speaker 1: doesn't come in infinitely small bits of light, Like there's
23:29
Speaker 1: chunks of light, that's right. Yeah, Einstein was looking at
23:32
Speaker 1: some experiments that didn't quite make sense, and the only
23:34
Speaker 1: way he could explain them was if light came in
23:37
Speaker 1: little packets. And that's what quantum means. Quantum means a
23:41
Speaker 1: unit or a packet, and so he suggested that maybe
23:44
Speaker 1: light comes in these little packets. But then it had
23:46
Speaker 1: all these far reaching consequences, you know, um about light
23:50
Speaker 1: going through mirrors and through prisms, and the way people
23:52
Speaker 1: could understand that was only if there were various probabilities
23:56
Speaker 1: for things to happen. And it began this whole revolution
23:58
Speaker 1: of quantum mechanics, which then Einstein tried to put the
24:01
Speaker 1: brakes on, right. He was like, way, a hold on
24:02
Speaker 1: a second, guys, this is crazy talk. There's no way
24:05
Speaker 1: the universe works this way, meaning like um, this idea
24:09
Speaker 1: of quantum stuff only made sense if the universe work
24:12
Speaker 1: based on probabilities, not like deterministically. You know, you have
24:16
Speaker 1: to describe things with wave functions, and things aren't really
24:19
Speaker 1: like point particles are kind of fuzzy things. That's exactly
24:23
Speaker 1: the point is that there's this fuzziness in the universe
24:25
Speaker 1: and quantum mechanics because there's these minimum sized objects and
24:29
Speaker 1: the way they interfere with each other and the way
24:30
Speaker 1: the calculations happen. Quantum mechanics predicts that the universe is
24:34
Speaker 1: fundamentally random, and it means that, for example, you have
24:37
Speaker 1: an electron, you don't know exactly where it is. There's
24:40
Speaker 1: a probability distribution that says, most likely it's here, maybe
24:43
Speaker 1: it's there, maybe it's somewhere else. Is it that we
24:46
Speaker 1: can't is it like a randomness, like we can't uh
24:50
Speaker 1: know where it is, or that there's this trade off
24:53
Speaker 1: between like momentum and position. Right, that's exactly the right question,
24:57
Speaker 1: and that's exactly what people are asking. They looked at
25:00
Speaker 1: these equations and they said, well, is it that we
25:02
Speaker 1: can't predict where the electron is, like it's totally impossible
25:06
Speaker 1: to predict, or is it that we just don't know
25:09
Speaker 1: where it is that we haven't figured out how to
25:11
Speaker 1: get that information, right. Does the information not exist or
25:14
Speaker 1: do we just not have it? And so Einstein is
25:17
Speaker 1: the one who said there must be some hidden variable.
25:19
Speaker 1: There must be something that's that these particles are carrying,
25:22
Speaker 1: some piece of information that determines exactly what's going to
25:25
Speaker 1: happen to them, but we just don't know what it is.
25:28
Speaker 1: To him, it was crazy to think that you could
25:30
Speaker 1: shoot an electron into an experiment twice and get two
25:33
Speaker 1: different answers. But that's appeared. What appeared to happen. People
25:36
Speaker 1: set up these careful experiments where you would shoot a
25:40
Speaker 1: photon one at a time. You would shoot photons into
25:43
Speaker 1: an experiment, and every photon would do something different, and
25:46
Speaker 1: then as you would accumulate a bunch of photons, it
25:49
Speaker 1: would add up to give you a distribution that made
25:52
Speaker 1: sense to you. Just the same way when you flip
25:54
Speaker 1: a coin, you get heads, you get tails, you get heads,
25:56
Speaker 1: you get tails. It seems random, but eventually it builds
25:59
Speaker 1: up to fifty fifty. Right. Quantum mechanics tells us all
26:02
Speaker 1: we can do is predict the eventual distribution. We can say,
26:06
Speaker 1: if you measure a thousand electrons, some of them will
26:09
Speaker 1: go here and some of them will go there. It
26:10
Speaker 1: says you can't predict any individual one. All you can
26:13
Speaker 1: predict is the distribution of outcomes. So Eisland was like,
26:17
Speaker 1: maybe a photon is kind of like the coin we
26:20
Speaker 1: were talking about before, Like maybe it seems random to us,
26:22
Speaker 1: but really it's just kind of this chain of of
26:25
Speaker 1: little local events that actually make it predictable. That's right,
26:30
Speaker 1: if we knew all that information inside, Like maybe it
26:33
Speaker 1: just looks fuzzy to us that we can't tell where
26:35
Speaker 1: it is, but inside that particle really actually knows where
26:38
Speaker 1: it is. It's exactly right. That's what he wanted to believe, right,
26:41
Speaker 1: That's what he wanted to believe. And you've got to
26:42
Speaker 1: sympathize with the guy. Right, it's hard to imagine that
26:45
Speaker 1: the universe would not be deterministic. I mean, we spent
26:48
Speaker 1: hundreds of years building up our confidence in science and
26:51
Speaker 1: his physics, especially as being able to predict the future,
26:54
Speaker 1: and and just of saying basically, the universe follows rules. Right,
26:57
Speaker 1: So now all of a sudden you're telling us what
26:59
Speaker 1: there's like dice in there is there some randomness? Like
27:02
Speaker 1: every time you shoot an electron to your experiment, somebody
27:05
Speaker 1: or something or the universe is making a like a
27:07
Speaker 1: random decision about where it's going to go. It seems crazy,
27:10
Speaker 1: So you're absolutely right. And he suggested that a simpler
27:13
Speaker 1: explanation is that they're carrying along another piece of information
27:16
Speaker 1: that we just don't have access to or can't measure,
27:19
Speaker 1: or didn't measure, and that that's actually determining in a
27:22
Speaker 1: totally predictable way what's going to happen to each particle.
27:25
Speaker 1: That was his solution to the problem. Well, he famously
27:28
Speaker 1: said God doesn't play dice, right, He's famously quoted as
27:31
Speaker 1: saying that, I'm not sure he actually did, but it's
27:34
Speaker 1: really but it's a pretty good summary of what he believed.
27:37
Speaker 1: Fake news, well, like a lot of fake news is
27:42
Speaker 1: a cronel of truth in it. Um. He certainly wanted
27:46
Speaker 1: to believe in a deterministic universe and it made sense
27:48
Speaker 1: to him. And you know what, it makes sense to me.
27:50
Speaker 1: I mean the idea that there's like a tor random
27:53
Speaker 1: number generator somewhere in the universe that's making a decision
27:57
Speaker 1: every time you're shoot an electron into something. It's doesn't
28:00
Speaker 1: make any sense. To me intuitively. You know, not that
28:02
Speaker 1: the universe has to make sense to me intuitively, but
28:05
Speaker 1: it doesn't. So you're saying the quantum mechanics says that
28:11
Speaker 1: there is a randomness in things, And so where is
28:14
Speaker 1: that randomness actually in like the position of particles in
28:17
Speaker 1: the verse of the velocity um, in their like very being,
28:22
Speaker 1: in their energy level? What where is this randomness of everything? Well,
28:25
Speaker 1: there's randomness at every level. I mean there's a randomness
28:29
Speaker 1: between every time you look at something. So say, for example,
28:32
Speaker 1: you measure an electron, you see it's a certain place,
28:35
Speaker 1: then you look away, right, because you can't monitor an
28:38
Speaker 1: electron every moment or every nanosecond ven you look away,
28:41
Speaker 1: what is the electron do between when you last saw
28:44
Speaker 1: it and when you'll next see it? Meaning like, if
28:47
Speaker 1: I know where it is and how fast it's going,
28:49
Speaker 1: and then I look away and I look again, is
28:51
Speaker 1: it going to be where I think it's going to be? Yes, exactly.
28:54
Speaker 1: And so every every moment of an electron or a
28:58
Speaker 1: particle's life is determined by quantum mechanics, which says there's
29:01
Speaker 1: a probability distribution. It's not like the electron is doing
29:05
Speaker 1: something behind your back. It's got one particular path that
29:08
Speaker 1: you're just not aware of behind your back, and you
29:10
Speaker 1: just don't know it. It doesn't have a specific path.
29:13
Speaker 1: It's not like it goes from a to via a
29:16
Speaker 1: particular path. It has a probability of different ways to
29:20
Speaker 1: get there, and if you don't look, then it's sort
29:23
Speaker 1: of doing all of them at once. They all have
29:25
Speaker 1: different probabilities, and those probabilities are the things determined by
29:28
Speaker 1: the laws of physics. So there's still are laws. Physics
29:32
Speaker 1: still does tell the universe how to run. It's just
29:34
Speaker 1: that those laws are probabilistic. It says, look, Mr Electron,
29:38
Speaker 1: instead of telling you exactly where you're gonna go, I'm
29:40
Speaker 1: gonna say you have a seventy percent chance of doing
29:42
Speaker 1: this and the thirty percent chance of doing that. So
29:44
Speaker 1: that's where the fuzziness and the randomness comes in. It's
29:46
Speaker 1: not that it like it looks fuzzy, it's just that
29:49
Speaker 1: it's just hard to predict where it's going to be.
29:51
Speaker 1: It's impossible. You know all this information, it's impossible. It's
29:54
Speaker 1: impossible to predict the future. Impossible exactly, you can predict
29:58
Speaker 1: the various likelihood of the So the likelihood of that
30:01
Speaker 1: at the particle level, but you can't say what one
30:03
Speaker 1: particle is going to do. Now, Einstein said, that's crazy, right,
30:07
Speaker 1: there's no way that's true. There must be a way
30:09
Speaker 1: to predict it must be there some piece of information there.
30:12
Speaker 1: And then some guys came up with an experiment. They
30:14
Speaker 1: came up with this crazy experiment. It's based on an
30:16
Speaker 1: idea called Bell's inequality. To test this theory, they said,
30:21
Speaker 1: let's see if the universe is really random, or if
30:24
Speaker 1: there's some hidden piece of information that's actually secretly determining things,
30:28
Speaker 1: like let's see if if I really can't predict for
30:31
Speaker 1: that electron is going to go, or if it's actually
30:34
Speaker 1: like the electron knows it just won't tell us. Yeah, right, exactly. Um.
30:38
Speaker 1: And so they set up this cool experiment where they
30:40
Speaker 1: took a particle and they had to shoot out two
30:44
Speaker 1: particles in opposite directions. And those particles are therefore connected
30:47
Speaker 1: because they have to conserve momentum, they have to conserve
30:50
Speaker 1: energy and have to conserve spin. And so if you
30:53
Speaker 1: know something about one particle, that you know something about
30:55
Speaker 1: the other particles, but both particles have equal probability to
30:58
Speaker 1: be like spin up or spin down own, or point
31:00
Speaker 1: this way a point the other way, but you know
31:02
Speaker 1: something about the combination of the two. And so they
31:05
Speaker 1: came up with this really ingenious experiment to measure how
31:08
Speaker 1: often you saw one spin up and one's been down,
31:11
Speaker 1: for example, And based on the outcome of that, you
31:14
Speaker 1: could tell whether there was a secret, hidden um piece
31:17
Speaker 1: of information that was controlling both particles, or whether they
31:21
Speaker 1: were both truly random. And the experiments are conclusive, and
31:24
Speaker 1: it's been done a zillion times, and the experiment tells
31:27
Speaker 1: us that the universe at its core really is random.
31:30
Speaker 1: That's making a random decision every time you look at
31:33
Speaker 1: these particles. So beyond the shadow of a doubt, we
31:37
Speaker 1: know that the universe is random. The universe is random. Absolutely.
31:41
Speaker 1: There's no no escape clause, there's no if hands or
31:46
Speaker 1: but there's no asteris no loopholes. The universe at the
31:50
Speaker 1: part of the level is really random. Now, you said
31:52
Speaker 1: something really interesting earlier. You know, even if the universe
31:55
Speaker 1: is random at the lowest level, that doesn't necessarily mean
31:59
Speaker 1: that it's a random at other levels. Right, Like we
32:02
Speaker 1: still got to the moon. Right, It's not like we're
32:04
Speaker 1: saying science doesn't work, or you shouldn't get in that airplane. Right.
32:07
Speaker 1: Science works at different at different levels, And even if
32:09
Speaker 1: it's random at the very very small level, doesn't mean
32:12
Speaker 1: that on average it's really predictable, right, Like we do
32:15
Speaker 1: know how basketball's bounce, right, And that's because the randomness
32:19
Speaker 1: only applies to these tiny little particles, and over the
32:22
Speaker 1: ten to the thirty or whatever particles in a basketball,
32:25
Speaker 1: that all averages out to something very very predictable. Wow,
32:28
Speaker 1: So like random events Canada add up to predictable events?
32:32
Speaker 1: Is that kind of what you're saying? Yeah, exactly. Like
32:34
Speaker 1: you can't tell how any individual voter is going to vote,
32:37
Speaker 1: but if you've done enough polls, you can tell if
32:40
Speaker 1: you know how the nation is going to vote. Um
32:42
Speaker 1: at a certain reduction that worked out so well in election.
32:46
Speaker 1: Maybe that wasn't the best example totally predictable. At the
32:53
Speaker 1: level of particles, there is randomness, but maybe in the
32:58
Speaker 1: macro scale things are fairly predictable. But how does that
33:01
Speaker 1: affect things like free will? Does that mean that, like
33:04
Speaker 1: my brain just quantum randomness give me some sort of
33:09
Speaker 1: unpredictability or free will as you might call it, Or
33:13
Speaker 1: is my brain also very predictable in the long run.
33:16
Speaker 1: It's a great question, and into this tiny crack and determinism,
33:19
Speaker 1: you know, saying that at the particle level, things are
33:22
Speaker 1: truly random. And there's flooded and enormous literature of consciousness
33:27
Speaker 1: and all sorts of philosophy that that try to connect
33:30
Speaker 1: free will to quantum randomness, you know, to say that
33:33
Speaker 1: this is the whole we needed, This is what breaks
33:34
Speaker 1: determinism and allows for me and my soul and God
33:38
Speaker 1: and all the and and all the things you want
33:40
Speaker 1: to cram into your universe. I'm not convinced that quantum
33:44
Speaker 1: mechanics allows for free will, or for souls or you know,
33:48
Speaker 1: for all that kind of stuff, but it certainly does
33:51
Speaker 1: dismantle the deterministic watch like universe that we thought we
33:54
Speaker 1: had MM. So just because something is random doesn't mean
33:57
Speaker 1: you have free will. Like it's just random, exactly exactly.
34:02
Speaker 1: And so to answer the question, you know, is the
34:05
Speaker 1: universe random or is it chaotic? Turns out it's kind
34:08
Speaker 1: of both. Right, It's a random at the particle level,
34:11
Speaker 1: but it's chaotic at the macroscopic level. Right, things do
34:15
Speaker 1: seem to be fairly deterministic at the macroscopic level, but
34:18
Speaker 1: then again they're too chaotic to really to really model.
34:22
Speaker 1: So it's not like you can predict the weather. It's
34:24
Speaker 1: kind of a progression. Like it's random at the particle level.
34:26
Speaker 1: It's kind of deterministic at a medium range level, but
34:29
Speaker 1: then as you get too larger and larger systems, then
34:31
Speaker 1: it's chaotic and it's practically unpredictable. Yeah, yeah, exactly right.
34:36
Speaker 1: So any answer you want there's someplace in the universe
34:39
Speaker 1: is yeah, I just pick a random, random answer and
34:47
Speaker 1: it will be that. So maybe that's why people answer
34:49
Speaker 1: with such a such streams of gibberish to our our question,
34:52
Speaker 1: because because they really deeply understood that the universe was
34:55
Speaker 1: both random and chaotic. Wow, the wisdom of the some
35:00
Speaker 1: in the crowd. Exactly, you average over ten random people
35:03
Speaker 1: and there is some insight there. Exactly. That's the whole
35:05
Speaker 1: that's the whole problem. Answer is the answer is yes.
35:10
Speaker 1: So I think it's it's fun to think about that
35:12
Speaker 1: in so the larger context. You know, like we started
35:14
Speaker 1: off thinking the universe was crazy, then we started to
35:17
Speaker 1: get some grips on it. Then we felt like, oh,
35:19
Speaker 1: maybe the universe is sort of too tight a grip
35:21
Speaker 1: on us because it seems deterministic, and then we've got
35:23
Speaker 1: this crack thanks to quantum mechanics. It says it's random.
35:26
Speaker 1: But I don't really know how comfortable people are with
35:28
Speaker 1: that crack. You know, to think that the universe doesn't
35:32
Speaker 1: know what it's going to do at any moment, like
35:33
Speaker 1: they could do this, it could do that. That's sort
35:36
Speaker 1: of terrifying. I understand Einstein's fear that Einstein is dislike
35:40
Speaker 1: or disdain for that um, and that leaves us in
35:42
Speaker 1: a sort of uncomfortable position. And it might get even crazier, right, Like,
35:46
Speaker 1: let's say that we build quantum computers and then there's
35:48
Speaker 1: AI based on quantic computers. That that would be even crazier, right, Yeah,
35:53
Speaker 1: I'd love to read that science fiction novel that's how
35:55
Speaker 1: that's how AI develops free will, Right, quantum computers maybe
36:00
Speaker 1: more than us, that's exactly right. All right, Well, thank
36:07
Speaker 1: you for joining us. I hope that didn't seem like
36:09
Speaker 1: a random, random or chaotic discussion. But those are really
36:14
Speaker 1: fun topics. I think it's super fun to try to
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Speaker 1: wrap your mind around those things. And you know, one
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Speaker 1: of the basic questions of physics is not just what
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Speaker 1: is the world made out of? What are the bits
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Speaker 1: and pieces? Were like, what are the rules? And are
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Speaker 1: their rules? And and you know, can we ever understand it?
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Speaker 1: To me, that's one of the deepest questions of science
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Speaker 1: and and this goes right to the heart of it.
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Speaker 1: So if you're a butterfly out there, keep on flatting exactly.
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Speaker 1: If you still have a question after listening to all
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Speaker 1: these explanations, please drop us a line. We'd love to
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Speaker 1: hear from you. You can find us at Facebook, Twitter,
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Speaker 1: and Instagram at Daniel and Jorge that's one word, or
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Speaker 1: email us at Feedback at Daniel and Jorge dot com.
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Speaker 1: M