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What is the quantum internet? · Daniel and Kelly’s Extraordinary Universe

• 0:06
  Speaker 1: If you want to talk about your sincere awe and
• 0:09
  Speaker 1: wonder at the incredible physical universe, I'm here for that.
• 0:13
  Speaker 1: If you want to have cold water throne of your
• 0:15
  Speaker 1: dreams of space colonization, Kelly is at your service. Today
• 0:20
  Speaker 1: we're going to flip that script a little bit. It's
• 0:22
  Speaker 1: my turn to be a wet blanket about overhyped technology.
• 0:26
  Speaker 1: But along the way you learn just how amazing and
• 0:29
  Speaker 1: weird our universe really is. No hype necessary, that's right.
• 0:33
  Speaker 1: Today we are tackling physics buzzwords two of my favorites, actually, quantum,
• 0:39
  Speaker 1: probably the most overused word in pop side journalism, and
• 0:43
  Speaker 1: the Internet, the classic woid make anything sound more high
• 0:46
  Speaker 1: tech Internet of Things was supposed to make your toaster
• 0:49
  Speaker 1: seem like something from the future. Right, So today we'll
• 0:52
  Speaker 1: explore the science and the hype and the actual amazing,
• 0:55
  Speaker 1: beautiful physics behind a pair of buzzwords that have come
• 0:59
  Speaker 1: together to make a splash in the news. The quantum Internet.
• 1:03
  Speaker 1: It's not the latest ant Man movie, it's today's topic.
• 1:07
  Speaker 1: Welcome to Daniel and Kelly's Extraordinary quantum Universe.
• 1:25
  Speaker 2: Hello, I'm Kelly Wiener Smith. I study parasites and space
• 1:28
  Speaker 2: and when we come up with quantum parasites, you all
• 1:31
  Speaker 2: better be worried.
• 1:34
  Speaker 1: Hi, I'm Daniel, I'm a particle physicist, and the only
• 1:37
  Speaker 1: kind of parasite I want is a quantum one. I
• 1:38
  Speaker 1: don't want two point seventy two tapeworms. I want zero
• 1:41
  Speaker 1: or one, preferably zero.
• 1:43
  Speaker 2: Oh, but you really don't know until you actually look.
• 1:46
  Speaker 2: You know, until you put the scope down your digestive system,
• 1:50
  Speaker 2: you don't actually know if there's one in there or not.
• 1:52
  Speaker 1: That's true Schrodinger's tapeworm.
• 1:54
  Speaker 2: Oh fantastic.
• 1:55
  Speaker 1: But now I have a real question for you. Can
• 1:57
  Speaker 1: you have a non integer number of parasites? They pit
• 2:00
  Speaker 1: in some weird way where you're like, hm, I'm not
• 2:01
  Speaker 1: really sure if that's another one, But.
• 2:03
  Speaker 2: You gotta have hard to count things. So, the way
• 2:06
  Speaker 2: tapeworms work is they've got a head. The head holds
• 2:08
  Speaker 2: onto part of your body, and then they form segments
• 2:10
  Speaker 2: called proglottieds, and each proglotted makes its own sets of eggs,
• 2:14
  Speaker 2: And sometimes the proglotted dissolves away and the eggs pass
• 2:17
  Speaker 2: with your feces into the environment. Other times, the proglotted
• 2:20
  Speaker 2: just pops off and passes with your feces, and sometimes
• 2:23
  Speaker 2: it looks like pieces of rice walking around in your feces,
• 2:26
  Speaker 2: and that's proglotted, and so you can have you know,
• 2:28
  Speaker 2: like pieces of the tapeworm that sort of like separate
• 2:31
  Speaker 2: but are still moving. But we usually count how many
• 2:34
  Speaker 2: tapeworms an organism has based on the number of heads
• 2:37
  Speaker 2: that you find. So that's pretty straightforward.
• 2:41
  Speaker 1: So parasites are quantized. There you go, amazing. We went
• 2:44
  Speaker 1: from quantum physics to parasites to poop in record time
• 2:48
  Speaker 1: on the podcast. That's what happens when you have a
• 2:50
  Speaker 1: particle physicist and a parasitologist.
• 2:52
  Speaker 2: Yeah, but you're right, we got there pretty fast. Today.
• 2:53
  Speaker 2: I'm having a good day. We're having a good.
• 2:55
  Speaker 1: Day, all right, and we are moving at the speed
• 2:58
  Speaker 1: of information, trying to understand how the universe works and
• 3:00
  Speaker 1: sending it to you down the Internet tubes.
• 3:03
  Speaker 2: So there's a lot of misinformation out there about parasites.
• 3:05
  Speaker 2: So there's also a lot of misinformation out there about
• 3:07
  Speaker 2: what the word quantum means. So, Daniel, today we're talking
• 3:10
  Speaker 2: about quantum Internet.
• 3:13
  Speaker 1: Yeah, that's right, the latest word to have quantum slapped
• 3:16
  Speaker 1: in front.
• 3:16
  Speaker 2: Of it, that's right. So today we're gonna find out
• 3:18
  Speaker 2: if that makes any sense, and if it's nearly as
• 3:20
  Speaker 2: exciting as it sounds like it is on social media.
• 3:25
  Speaker 1: And I'm not actually that upset about the misinformation about
• 3:27
  Speaker 1: quantum mechanics because it gives me an opportunity to clarify
• 3:30
  Speaker 1: how amazing the universe actually is. It's not really a
• 3:33
  Speaker 1: wet blanket moment where you're like, this sounded amazing, but
• 3:36
  Speaker 1: it's really actually boring and nothing. It's like this sounds amazing,
• 3:39
  Speaker 1: but the reality is even more cool.
• 3:41
  Speaker 2: I mean, I don't know why you gotta sound so
• 3:43
  Speaker 2: down on wet blanket people, but all right, fine, I
• 3:45
  Speaker 2: know you like to keep things upbeat around here.
• 3:48
  Speaker 1: Oh I see you thought I was throwing a wet
• 3:50
  Speaker 1: blanket on the wet blanket people.
• 3:51
  Speaker 2: Well, on me in particular. I felt seen, but not
• 3:55
  Speaker 2: in no way.
• 3:58
  Speaker 1: I wasn't talking about you, but I think it says something.
• 4:01
  Speaker 1: He responded that way.
• 4:03
  Speaker 2: Yeah, you might be right.
• 4:05
  Speaker 1: All right, So let's hear how our listeners responded. I
• 4:08
  Speaker 1: went out there and asked them if they knew anything
• 4:10
  Speaker 1: about the quantum Internet, if you would like to contribute
• 4:13
  Speaker 1: your thoughts for future episodes, we would love to hear
• 4:15
  Speaker 1: from you. Please write to us two questions at Danielankelly
• 4:19
  Speaker 1: dot org and you can join the choir. In the meantime,
• 4:22
  Speaker 1: think about it for a minute. What is the quantum Internet?
• 4:25
  Speaker 1: What does it mean? Here's what our listeners had to say.
• 4:29
  Speaker 2: What is the quantum Internet? Now you're just making stuff up.
• 4:33
  Speaker 3: I have no idea, but I'm willing to learn.
• 4:38
  Speaker 1: I assume the quantum Internet is the Internet that joins
• 4:40
  Speaker 1: together quantum computers. Well, it sounds like the interconnected web
• 4:46
  Speaker 1: of sub atomic consciousness, or maybe where Antman hangs out.
• 4:52
  Speaker 2: The quantum Internet is great and all, but every time
• 4:55
  Speaker 2: I check my emails they're both read and unread at
• 4:58
  Speaker 2: the same time. I would guess that's internet that can
• 5:01
  Speaker 2: travel the quantum realm to go faster than the speed
• 5:06
  Speaker 2: of light.
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  Speaker 3: I would assume that it is a network of computers
• 5:11
  Speaker 3: that have all been based on quantum computing infrastructure and
• 5:17
  Speaker 3: quantum computing nodes.
• 5:20
  Speaker 1: Maybe the quantum Internet is to do with the Internet
• 5:23
  Speaker 1: being both truthful and untruthful at the same time. I
• 5:27
  Speaker 1: suspect mostly untruthful. The quantum Internet will know what you're
• 5:32
  Speaker 1: searching for before you type it in. If someone asks
• 5:36
  Speaker 1: me what quantum Internet is.
• 5:40
  Speaker 2: I would say that that is the current structure of
• 5:43
  Speaker 2: our Internet.
• 5:44
  Speaker 1: It's either your email sent or not sent. At the
• 5:48
  Speaker 1: same time, It's probably a place where astiophysicists and people
• 5:52
  Speaker 1: who use quantum data exchange information.
• 5:55
  Speaker 3: I've never heard of the quantum internet before, but perhaps
• 5:59
  Speaker 3: use of quantum computers on the Internet. I'm assuming it
• 6:04
  Speaker 3: could do all sorts of neat things that we can't
• 6:07
  Speaker 3: even imagine now. It could just be an entire Internet
• 6:10
  Speaker 3: filled with cats in boxes, and I'm okay with that.
• 6:14
  Speaker 3: The quantum Internet is a marketing term that's really just us.
• 6:18
  Speaker 1: I can't say what the quantum Internet is, but I
• 6:20
  Speaker 1: can calculate various probabilities of what it might be. The
• 6:24
  Speaker 1: quantum Internet is the name for the observation that any
• 6:27
  Speaker 1: fact you find on the Internet is equally likely to
• 6:29
  Speaker 1: be true or untrue.
• 6:31
  Speaker 2: There were some really fantastic answers here where your emails
• 6:34
  Speaker 2: are both read and unread at the same time. I
• 6:37
  Speaker 2: love that. I wonder if you get out of trouble
• 6:40
  Speaker 2: if you're like, well, I know it was read and
• 6:42
  Speaker 2: it was unread, and so I answered it and didn't
• 6:44
  Speaker 2: answer it, but like, you know, move on.
• 6:46
  Speaker 1: Yeah, as usual, people either knew the answer, were wildly
• 6:49
  Speaker 1: off or hilarious. I love this mixture. I always look
• 6:52
  Speaker 1: forward to listening to these. There's so much fun.
• 6:54
  Speaker 2: Yep, I love y'all.
• 6:56
  Speaker 1: Thanks everybody.
• 6:57
  Speaker 2: This I think gave a really nice overview of the
• 7:00
  Speaker 2: various thoughts that people have about quantum internet, what it does,
• 7:03
  Speaker 2: or whether or not they have any idea at all
• 7:05
  Speaker 2: what it does. So let's just start from the beginning, like,
• 7:09
  Speaker 2: what is quantum internet.
• 7:11
  Speaker 1: Yeah, quantum internet is actually a real thing. It's not
• 7:15
  Speaker 1: total nonsense. It's the idea that you could take quantum computers,
• 7:19
  Speaker 1: which we'll dig into in a minute, and you could
• 7:21
  Speaker 1: connect them in a quantum mechanical way, not in the
• 7:25
  Speaker 1: same way that we connect normal classical computers that ship
• 7:28
  Speaker 1: bits back and forth, but you could connect them using
• 7:30
  Speaker 1: a fancy technology called quantum teleportation, which helps you move
• 7:35
  Speaker 1: quantum information between one computer and another. And it makes
• 7:39
  Speaker 1: sort of sense, like we used to develop computers, and
• 7:42
  Speaker 1: then we networked all the computers together because that has
• 7:44
  Speaker 1: obvious advantages, sharing information, working in parallel, et cetera. And
• 7:48
  Speaker 1: now we're developing quantum computers, and so you might think, oh,
• 7:51
  Speaker 1: it could be beneficial to connect quantum computers to each
• 7:54
  Speaker 1: other because maybe they could take over the world and
• 7:57
  Speaker 1: enslave us. No, I mean calculate our taxes faster, whatever
• 8:00
  Speaker 1: quantum computers are supposed to do. So the quantum Internet
• 8:03
  Speaker 1: really is two different ideas. It's quantum computers connected together
• 8:06
  Speaker 1: with quantum teleportation.
• 8:08
  Speaker 2: Oh that sounds very star treky. But so my understanding
• 8:12
  Speaker 2: of quantum computers is that we sort over getting a
• 8:15
  Speaker 2: handle on it. But this is not something that you use,
• 8:18
  Speaker 2: like every day to solve normal problems. Yep, connecting quantum
• 8:21
  Speaker 2: computers it feels like you're jumping ahead five or six steps, Like,
• 8:24
  Speaker 2: shouldn't we get the computers to work first?
• 8:26
  Speaker 1: Well, I don't know. I think we should work on
• 8:28
  Speaker 1: all the problems at the same time. Right, It's not
• 8:31
  Speaker 1: like we should finish physics before we get started on biology,
• 8:34
  Speaker 1: because it's the colvision of everything, right, right, I'm agreeing
• 8:37
  Speaker 1: with you.
• 8:37
  Speaker 2: I mean, you need to be motivated, and how can
• 8:39
  Speaker 2: you stay motivated if you're just doing physics. You need
• 8:41
  Speaker 2: the good stuff too.
• 8:42
  Speaker 1: You're right, we can't use the quantum Internet without quantum computers.
• 8:46
  Speaker 1: But we also don't want to wait until quantum computers
• 8:48
  Speaker 1: are a full fledged thing before we start thinking about
• 8:50
  Speaker 1: how to connect them. And you know, everybody out there
• 8:53
  Speaker 1: is excited about different stuff. So there's a group out
• 8:55
  Speaker 1: there that recently made a splash because of their advance
• 8:58
  Speaker 1: in quantum connection quantum computers, and we're going to talk
• 9:01
  Speaker 1: about that in a minute, and that's why it's in
• 9:03
  Speaker 1: the news. But I think it's a good idea to
• 9:05
  Speaker 1: push on all fronts simultaneously.
• 9:07
  Speaker 2: All right, fair enough, there's enough people excited about the question.
• 9:10
  Speaker 2: You can work on more than one front. Can you
• 9:12
  Speaker 2: give us a quick explanation of what a quantum computer is?
• 9:16
  Speaker 1: Right? So, the quantum Internet is a quantum connected bunch
• 9:19
  Speaker 1: of quantum computers. The core that is a quantum computer.
• 9:22
  Speaker 1: What is a quantum computer? And so there is so
• 9:25
  Speaker 1: much misunderstanding and misinformation about quantum computers, especially recently because
• 9:29
  Speaker 1: of Microsoft results and Google's claims and clickbait writing articles.
• 9:33
  Speaker 1: Quantum computers are not computers that do infinite number of
• 9:37
  Speaker 1: computations in parallel. They are not computers that tap into
• 9:40
  Speaker 1: the multiverse. There are computers that use quantum mechanics to
• 9:43
  Speaker 1: do calculations instead of using classical physics. Or just normal bits. Right,
• 9:48
  Speaker 1: So in a classical computer, the one that I'm using
• 9:51
  Speaker 1: right now to record this podcast episode, and the one
• 9:54
  Speaker 1: that's inside your phone or whatever device you're listening on,
• 9:57
  Speaker 1: there's a bunch of bits. There's zeros and ones, and
• 9:59
  Speaker 1: all of computation involves calculating new bits and flipping bits.
• 10:03
  Speaker 1: You know. For example, when you take a picture, it's
• 10:05
  Speaker 1: stored in terms of those bits. When you add two numbers,
• 10:09
  Speaker 1: it expresses those numbers in binary form, where every digit
• 10:12
  Speaker 1: is a bit, a zero or one, and it adds
• 10:14
  Speaker 1: them in binary form. So the lifeblood of normal computers
• 10:18
  Speaker 1: are these bits that are zero or one, and we
• 10:21
  Speaker 1: use the rules of logic to build up a bunch
• 10:23
  Speaker 1: of stuff that computers can do. But that's just one
• 10:26
  Speaker 1: kind of computer, right. Technically, anything is a computer, like
• 10:30
  Speaker 1: a baseball is a computer. It just calculates only one thing,
• 10:34
  Speaker 1: like what a baseball can do. The cool thing about
• 10:37
  Speaker 1: digital computers, the ones we know and love, is that
• 10:39
  Speaker 1: they're programmable. We figure it out a way to take
• 10:42
  Speaker 1: advantage of this very basic operation and map into lots
• 10:45
  Speaker 1: and lots of really interesting problems. Cool, but there's some
• 10:48
  Speaker 1: things that classical computers are slow at you know, just
• 10:51
  Speaker 1: because you can map them into lots of things doesn't
• 10:53
  Speaker 1: mean that they're very good at things. You know, like
• 10:56
  Speaker 1: counting to a super high number. It can take a while.
• 10:59
  Speaker 1: Anybody who is like run a piece of code over
• 11:02
  Speaker 1: massive data that knows it can take a day or something,
• 11:05
  Speaker 1: even on fast computers. And so quantum computers say, well,
• 11:08
  Speaker 1: what if there's another way to do computation. Instead of
• 11:10
  Speaker 1: starting from something like a zero or one, let's start
• 11:13
  Speaker 1: from a state that's more ambiguous, like a cubebit. A
• 11:16
  Speaker 1: cubit is something that doesn't have to be zero or one.
• 11:19
  Speaker 1: It can have a probability to be zero and a
• 11:21
  Speaker 1: probably to be one, and so there's like more fuzz there.
• 11:24
  Speaker 1: And the rules of quantum mechanics are different from the
• 11:26
  Speaker 1: rules of digital logic, and so that maps to a
• 11:29
  Speaker 1: different set of problems that quantum computers can do quickly
• 11:32
  Speaker 1: or do slowly.
• 11:34
  Speaker 2: Maybe this was when we were talking to Scott Arenson
• 11:36
  Speaker 2: the other day. He said something about how quantum computers
• 11:39
  Speaker 2: are better when you want to solve quantumy problems or
• 11:42
  Speaker 2: things like protein folding, Like if I have a question
• 11:45
  Speaker 2: about parasites, I wouldn't make a computer out of parasites.
• 11:50
  Speaker 2: Why is using cubits make it easier to solve those
• 11:52
  Speaker 2: kinds of problems?
• 11:55
  Speaker 1: Well, actually, I disagree with you, Kelly. I think you
• 11:57
  Speaker 1: should build a parasite computer. And let me tell you why.
• 12:00
  Speaker 1: You know, Let's say you wanted to know what happens
• 12:02
  Speaker 1: on a certain quantum process, right, Well, one thing you
• 12:05
  Speaker 1: could do is you could try to simulate that process
• 12:08
  Speaker 1: on a classical computer. You could like represent it abstractly
• 12:11
  Speaker 1: using zeros and ones, and then encode the rules of
• 12:14
  Speaker 1: quantum physics into that digital logic and run it. It might
• 12:17
  Speaker 1: be kind of slow, or you could just ask the
• 12:20
  Speaker 1: quantum object itself. You're going to do the experiment, right, say, oh,
• 12:25
  Speaker 1: I'm just going to ask the universe. I'm gonna put
• 12:26
  Speaker 1: the quantum objects in that situation. I'm going to see
• 12:29
  Speaker 1: what happens, and then behind the scenes, the universe is
• 12:31
  Speaker 1: following those rules of quantum mechanics for you, and the
• 12:34
  Speaker 1: universe of the computation is free and kind of infinitely fast,
• 12:37
  Speaker 1: and so in comparison, if you wanted to know, Kelly,
• 12:40
  Speaker 1: like what happens if you drop a tapeworm into a
• 12:42
  Speaker 1: can of coke, Just drop the tapeworm into a can
• 12:45
  Speaker 1: of coke. That's a parasite computer right there. We think
• 12:48
  Speaker 1: about computing sort of narrowly, like what it can be
• 12:50
  Speaker 1: done in Excel. But computing is really just like getting
• 12:53
  Speaker 1: the answer to a question, and sometimes building the system
• 12:56
  Speaker 1: itself that you have a question about is the most
• 12:58
  Speaker 1: natural way to get the answer.
• 13:00
  Speaker 2: Okay, so one, I don't expect that Coke is going
• 13:02
  Speaker 2: to be running any ads on our website for our
• 13:05
  Speaker 2: podcast for the foreseeable future.
• 13:07
  Speaker 1: You don't think tapeworms like coke? What you think they
• 13:09
  Speaker 1: prefer something else? Are they pepsi fans?
• 13:11
  Speaker 2: I was going to make a joke about coke being
• 13:13
  Speaker 2: no worse once a tapeworm has dropped in there, But
• 13:15
  Speaker 2: I'm just kidding. I'm just kidding.
• 13:18
  Speaker 1: Wait, have you done that experiment? Do you know the
• 13:20
  Speaker 1: answer to that calculation?
• 13:21
  Speaker 2: I would never do something like that to a parasite.
• 13:25
  Speaker 2: Do I have dropped some ethanol and formaline?
• 13:28
  Speaker 1: So then, backing up to Scott's comment, is natural to
• 13:30
  Speaker 1: calculate quantum things using a quantum computer because it's simpler
• 13:33
  Speaker 1: to express them. It's likely to be fast. Now, in principle,
• 13:36
  Speaker 1: anything you can calculate on a quantum computer, you can
• 13:39
  Speaker 1: also calculate on a normal computer. Why because you can
• 13:42
  Speaker 1: simulate a quantum computer on a normal computer. Right, just
• 13:46
  Speaker 1: design one in your symbolic logic and let it run
• 13:49
  Speaker 1: and simulate the laws of quantum mechanics. It's going to
• 13:51
  Speaker 1: be slower the same way, like calculating exactly what happens
• 13:55
  Speaker 1: to a baseball could be slower than just throwing the baseball. Right,
• 13:58
  Speaker 1: let the universe do the computation. So the thing they
• 14:00
  Speaker 1: know about quantum computers is that it's a different way
• 14:03
  Speaker 1: to represent problems we might want to solve, and they're
• 14:06
  Speaker 1: fast or slow at different things than baseballs or tapeworms
• 14:09
  Speaker 1: or normal digital computers. So they're like a radically different
• 14:13
  Speaker 1: way to do computation, and potentially they're very powerful at
• 14:17
  Speaker 1: some problems. So, you know, there's some problems that we
• 14:19
  Speaker 1: think classical computers are going to be very very bad at.
• 14:22
  Speaker 1: For example, finding out if a number is prime. If
• 14:25
  Speaker 1: I give you a number, how do you know if
• 14:26
  Speaker 1: it's prime? Like if I ask you ninety seven, is
• 14:29
  Speaker 1: it prime? Well, technically you have to check all the
• 14:31
  Speaker 1: factors that might go into it. Well, undt a time.
• 14:34
  Speaker 1: I mean, there's some clever ways to do it to
• 14:36
  Speaker 1: be a little bit more efficient, but it's slow, and
• 14:38
  Speaker 1: as the number gets big, that stays slow. And amazingly,
• 14:42
  Speaker 1: there's a guy who figured out an algorithm to do
• 14:44
  Speaker 1: that on quantum computers much more rapidly than on digital computers.
• 14:47
  Speaker 1: So that's an example of a kind of problem which
• 14:50
  Speaker 1: for weird reasons, because of the way quantum bits come
• 14:53
  Speaker 1: together and the way we can map that problem to
• 14:56
  Speaker 1: mathematical problems, there are some things that would happen fast
• 15:00
  Speaker 1: on a quantum computer than on digital computers, but there's
• 15:02
  Speaker 1: a very small number of those problems. People think like, oh,
• 15:06
  Speaker 1: quantum computers can solve anything, you know, they can break
• 15:08
  Speaker 1: into anything, and they're often used as like the mcguffin
• 15:11
  Speaker 1: on these action movies, Right, don't let the terrorists get
• 15:14
  Speaker 1: the quantum computer, or they'll get your bank account. In reality,
• 15:17
  Speaker 1: cryptography is better protected than is often described in those movies,
• 15:21
  Speaker 1: and nobody has a quantum computer that's powerful enough really
• 15:23
  Speaker 1: to do anything more quickly than classical computers. So quantum
• 15:28
  Speaker 1: computers are a real thing. They're awesome in the future,
• 15:31
  Speaker 1: and we have bigger quantum computers with more bits, they
• 15:33
  Speaker 1: can maybe solve really interesting problems that otherwise would be
• 15:36
  Speaker 1: very slow on normal computers. But no, they're not proof
• 15:40
  Speaker 1: that the multiverse exists. They can do infinite computation in parallel,
• 15:44
  Speaker 1: and they're currently not really useful for anything.
• 15:46
  Speaker 2: A couple questions, all right, First, so you were talking
• 15:49
  Speaker 2: about bits being zero in one, and you're like, so
• 15:51
  Speaker 2: we're going to use something a little fuzzier that to
• 15:54
  Speaker 2: me doesn't necessarily seem like an easy way to get
• 15:57
  Speaker 2: a better answer. So our quantum computers. You said they're
• 16:00
  Speaker 2: better for some questions. Are they worse for a lot
• 16:03
  Speaker 2: of other questions?
• 16:04
  Speaker 3: Oh?
• 16:04
  Speaker 2: Yeah, okay, so they don't always beat classical computers. No, okay,
• 16:08
  Speaker 2: all right? And then you said they're not necessarily computing
• 16:12
  Speaker 2: in the multiverse. Do all of the quantum computer people
• 16:16
  Speaker 2: believe you, because I feel like I've heard some who
• 16:18
  Speaker 2: are like, maybe this does prove the existence of the multiverse.
• 16:21
  Speaker 2: Are you not teaching the controversy here, Daniel.
• 16:27
  Speaker 1: That's a fair question. I don't know anybody who I
• 16:29
  Speaker 1: take seriously in quantum mechanics who thinks that quantum computers
• 16:34
  Speaker 1: prove that the multiverse exists. I mean, how would you
• 16:36
  Speaker 1: even steal man that argument? I think the argument is
• 16:39
  Speaker 1: that quantum computers require superposition of multiple states. You know,
• 16:44
  Speaker 1: for example, like your baseball can only have one energy,
• 16:47
  Speaker 1: but an electron maybe it has a probability to have
• 16:50
  Speaker 1: two different energies. It could have this energy or the
• 16:52
  Speaker 1: other energy, or maybe it has two possible spins. It
• 16:54
  Speaker 1: can simultaneously be in two states, or more accurately, you
• 16:57
  Speaker 1: can say you can have the probability to be in
• 16:59
  Speaker 1: two states at the same time. This is something weird
• 17:02
  Speaker 1: that quantum objects can do. Quantum computation relies on this
• 17:05
  Speaker 1: because the law of quantum physics predicts what will happen
• 17:08
  Speaker 1: to each of those probabilities, and we map our problems
• 17:10
  Speaker 1: onto those quantum physics and use the outcomes of those
• 17:13
  Speaker 1: probabilities to get the answer. So it relies on superpositions existing.
• 17:17
  Speaker 1: But we've known superpositions exist for a long long time,
• 17:20
  Speaker 1: you know, like we have obvious examples of quantum superposition,
• 17:23
  Speaker 1: all the Bells experiments about quantum entanglement that we'll talk about,
• 17:26
  Speaker 1: the interferometer experiment, the double slid experiment, Like we have
• 17:28
  Speaker 1: proof that superposition is a real thing before quantum computers,
• 17:32
  Speaker 1: So like, I don't think because superposition is real, that
• 17:35
  Speaker 1: means there's any strong argument that the multiverse is real.
• 17:39
  Speaker 1: So I'm ninety nine point nine numb percent sure that
• 17:41
  Speaker 1: quantum computing folks would say that this is just hype.
• 17:44
  Speaker 2: Have you let the Marvel folks.
• 17:45
  Speaker 1: Know there's a universe in which the Marvel folks have
• 17:49
  Speaker 1: reached out to me for physics consulting, But it's not
• 17:52
  Speaker 1: this universe.
• 17:53
  Speaker 2: Oh bummer, bummer, all right, that might have been the
• 17:55
  Speaker 2: best universe to live in. But okay, so we've wrapped
• 17:57
  Speaker 2: our heads around quantum compute. So let's take a break
• 18:01
  Speaker 2: and when we get back, we're going to talk about
• 18:03
  Speaker 2: quantum teleportation. All right, and we're back, Daniel in Star
• 18:24
  Speaker 2: Trek is quantum teleportation how they move people from one
• 18:28
  Speaker 2: place to another?
• 18:30
  Speaker 1: You're gonna ask me about the physics of something totally fictional.
• 18:33
  Speaker 2: I love that.
• 18:34
  Speaker 1: That reminds me of when I used to give presentations
• 18:36
  Speaker 1: in elementary schools, and my favorite part about that was
• 18:39
  Speaker 1: always opening the Florida questions.
• 18:41
  Speaker 2: Uh huh.
• 18:41
  Speaker 1: And I remember one day getting a question that totally
• 18:43
  Speaker 1: stumped me, and the question was just very similar to
• 18:46
  Speaker 1: your question. Actually, it was Hey everyone, just a note.
• 18:50
  Speaker 1: While we were recording this episode, a minor earthquake hit
• 18:54
  Speaker 1: southern California and my office shook a little bit. We
• 18:57
  Speaker 1: decided to keep that audio in the record for the
• 19:00
  Speaker 1: sake of transparency about life in California.
• 19:03
  Speaker 2: They just got quake, Aleric, Oh do you feel it?
• 19:08
  Speaker 1: Yeah, I'm like literally shaking.
• 19:11
  Speaker 2: Are you still shaking?
• 19:13
  Speaker 1: Nope? We're done. Wow, that was cool.
• 19:15
  Speaker 2: Do you need to check in with anyone?
• 19:17
  Speaker 1: No, just run in the mid day in California. Some
• 19:23
  Speaker 1: kidner gardener asked me if lightsabers were real, would they
• 19:27
  Speaker 1: be made of liquid nitrogen?
• 19:29
  Speaker 2: Wow?
• 19:29
  Speaker 1: Wow, I don't even know how to answer that.
• 19:31
  Speaker 2: Yeah, where do you start.
• 19:33
  Speaker 1: Here's a kyber crystal, Like you want to walk you
• 19:36
  Speaker 1: through the physics of kyber crystals? Like, I don't know anyway,
• 19:39
  Speaker 1: I don't know how they do it in Star Trek.
• 19:41
  Speaker 1: But teleportation is a really interesting question philosophically, and you
• 19:44
  Speaker 1: probably know that because every time we have a science
• 19:46
  Speaker 1: fiction author on I ask them what they think teleportation means.
• 19:50
  Speaker 1: Even does teleportation mean like your actual bits disappear and
• 19:53
  Speaker 1: appear somewhere else, like these atoms are now there? Or
• 19:57
  Speaker 1: is it enough to tear you apart and rebuild you
• 20:00
  Speaker 1: at of different atoms with the same arrangement. Right, Is
• 20:03
  Speaker 1: it like a cut and paste? Is it like an
• 20:04
  Speaker 1: email of what's going on? What is required for teleportation? Anyway,
• 20:09
  Speaker 1: it's kind of a deep philosophical question. Where do you
• 20:11
  Speaker 1: stand on that, Kelly.
• 20:12
  Speaker 2: Yeah, you're dead?
• 20:14
  Speaker 1: Yeah?
• 20:14
  Speaker 2: Yeah, No, you die and you get brought back somewhere else.
• 20:16
  Speaker 2: You couldn't get me in one of those.
• 20:18
  Speaker 1: But that's only because I think you're assuming that they
• 20:20
  Speaker 1: get torn apart and rebuilt. What if there was an
• 20:22
  Speaker 1: actual teleportation device that took your actual atoms and appeared
• 20:26
  Speaker 1: them somewhere else, would you get into that?
• 20:28
  Speaker 2: I would be the one millionth person in line for that.
• 20:32
  Speaker 1: Okay, that was a yes. I heard a yes. We
• 20:35
  Speaker 1: have it on the air.
• 20:36
  Speaker 2: If you're in line in front of me, Daniel, then
• 20:38
  Speaker 2: I will give it a shot.
• 20:41
  Speaker 1: I would like my ashes teleported into the center of
• 20:43
  Speaker 1: the sun. How about that?
• 20:45
  Speaker 2: Oh? Interesting? All right, quantum teleportation. Let's step out of
• 20:48
  Speaker 2: Star Trek and into the real world. How does quantum
• 20:51
  Speaker 2: teleportation work?
• 20:53
  Speaker 1: Right? So, quantum teleportation is arguably not teleportation. I mean,
• 20:58
  Speaker 1: it depends again exactly what do you mean by teleportation
• 21:02
  Speaker 1: in that sense? But quantum teleportation is a way to
• 21:06
  Speaker 1: transmit a quantum state. You know, there's a difficulty here,
• 21:09
  Speaker 1: which is, like, let's say I have a particle in
• 21:11
  Speaker 1: some quantum state, And by a quantum state, I mean
• 21:13
  Speaker 1: like it has a probability to be this and a
• 21:15
  Speaker 1: probability to be that. Right, take an electron, for example,
• 21:18
  Speaker 1: and say it can just have two states up or down.
• 21:22
  Speaker 1: So let's say I have an electron and I've done
• 21:24
  Speaker 1: some complicated thing to it so that it has a
• 21:26
  Speaker 1: seventy percent chance of being up and the thirty percent
• 21:28
  Speaker 1: chance of being down.
• 21:29
  Speaker 2: Can you actually do that? Like, you can tinker with
• 21:32
  Speaker 2: the probability that it's up or down.
• 21:34
  Speaker 1: You can do lots of different stuff. Yeah, you can
• 21:36
  Speaker 1: construct an experiment so that electrons have whatever probability you
• 21:39
  Speaker 1: want of doing basically whatever. That's what experimentalists do. Yeah, exactly. Wow,
• 21:43
  Speaker 1: force the universe to do something cool. And so let's
• 21:46
  Speaker 1: say that's like the outcome of your calculation or whatever. Now,
• 21:50
  Speaker 1: maybe you want that information somewhere else, right, Maybe you
• 21:53
  Speaker 1: want this quantum state to exist not here in California,
• 21:56
  Speaker 1: but in some quantum computer in Virginia right where you're
• 21:59
  Speaker 1: gonna use that as the basis of your next colcolition
• 22:02
  Speaker 1: or I don't know whatever you folks do in Virginia
• 22:04
  Speaker 1: with quantum states.
• 22:05
  Speaker 2: I know that we don't get earthquake alerts.
• 22:11
  Speaker 1: Wow, too soon to superpoint. I'm sorry, No, it's fine.
• 22:15
  Speaker 1: And so if you want to copy a quantum state
• 22:17
  Speaker 1: from here to there, it's a little tricky because if
• 22:20
  Speaker 1: I interact with that electron, if I like measure it,
• 22:23
  Speaker 1: or if I touch it, or if I put in
• 22:25
  Speaker 1: a box, I risk collapsing its state. Right, the universe
• 22:29
  Speaker 1: allows things to stay in superposition till they interact with
• 22:32
  Speaker 1: something that can't be in superposition, like a classical object
• 22:35
  Speaker 1: like my eyeball or my detector or whatever, and then
• 22:37
  Speaker 1: the universe picks okay, spin up or okay spin down.
• 22:41
  Speaker 1: And that could be fine. But if what you want
• 22:43
  Speaker 1: to do is preserve the quantum superposition, not to collapse it,
• 22:47
  Speaker 1: and to copy that information somewhere else, then you do
• 22:49
  Speaker 1: something called quantum teleportation. So that's really what quantum teleportation
• 22:53
  Speaker 1: is is it transmits a quantum state from one system
• 22:56
  Speaker 1: to another without collapsing it, which is pretty cool. I
• 22:59
  Speaker 1: don't know over it really qualifies as teleportation.
• 23:02
  Speaker 2: Are you actually moving the electron from one place to another.
• 23:06
  Speaker 1: You're not at all moving the electron. You're moving the arrangement,
• 23:08
  Speaker 1: the quantum state. And so I have an electron here
• 23:11
  Speaker 1: in California, you have an electron in Virginia. I want
• 23:13
  Speaker 1: to get your electron in Virginia to have the same
• 23:15
  Speaker 1: quantum state as my electron. I'm not like putting it
• 23:18
  Speaker 1: on a ups truck and driving across the country. I
• 23:20
  Speaker 1: could do that, that's no big deal. But if I
• 23:22
  Speaker 1: just want to transmit the information the arrangement the quantum state,
• 23:26
  Speaker 1: that's what we call quantum teleportation. And some of the
• 23:29
  Speaker 1: folks I know in the foundations of quant mechanics really
• 23:32
  Speaker 1: hate that name. They're like, why they call it teleportation? Okay,
• 23:35
  Speaker 1: I know why, because it sounds cool, but it's not
• 23:36
  Speaker 1: really teleportation. It's misleading, and so it's important to understand
• 23:40
  Speaker 1: like what it actually means. But it kind of makes sense, right,
• 23:42
  Speaker 1: Like if you have a network of quantum computer it's
• 23:44
  Speaker 1: one basic thing you're going to want to do is
• 23:46
  Speaker 1: take a quantum state from one and copy it over
• 23:48
  Speaker 1: to another one so it can like continue the calculation
• 23:51
  Speaker 1: or whatever. So whatever you call it, it's an important
• 23:54
  Speaker 1: part of having networked quantum computers.
• 23:56
  Speaker 2: I feel like it's one of those darned if you do,
• 23:58
  Speaker 2: darned if you don't situations. You know, like you call
• 24:00
  Speaker 2: it teleportation and now it's awesome and I want to
• 24:02
  Speaker 2: hear more. Or you could be like, oh, Jupiter's rings
• 24:04
  Speaker 2: or ABC and D and I know I keep using
• 24:06
  Speaker 2: it as an example, but like that is so boring.
• 24:09
  Speaker 2: You've got to be kidding me. So trying to find
• 24:11
  Speaker 2: the sweet spot for naming these things is tough.
• 24:13
  Speaker 1: What would you call Jupiter's rings, Kelly.
• 24:15
  Speaker 2: Well, I'm going to need some time to think about that.
• 24:17
  Speaker 2: I don't know.
• 24:18
  Speaker 1: I'm sorry you've been complaining about the name for weeks.
• 24:20
  Speaker 2: You're right, oh, man, putting me on the spot.
• 24:23
  Speaker 1: I'm just calling your bluff, that's all.
• 24:25
  Speaker 2: Yeah, you are calling my bluff. Hmm. What's the name
• 24:27
  Speaker 2: of the ring and Lord of the rings? Crashous that's
• 24:31
  Speaker 2: what Gollum calls it.
• 24:32
  Speaker 1: That's what Gollum calls it. Yeah. The efficient name is
• 24:35
  Speaker 1: something in Elvish, isn't it.
• 24:36
  Speaker 3: No?
• 24:36
  Speaker 2: Yeah, anyway, all right, focusing again, Okay, quantum teleportation we
• 24:40
  Speaker 2: understand what that is now. And you said that we
• 24:42
  Speaker 2: can connect an electron in California to an electron in Virginia.
• 24:47
  Speaker 2: Mm hmmm, how does that process work?
• 24:50
  Speaker 1: Yeah, so to do that, we're gonna have to use
• 24:52
  Speaker 1: something called quantum entanglement. So we're three layers deep. Now.
• 24:56
  Speaker 1: Quantum Internet requires quantum computers connected by quantum teleport rotation,
• 25:01
  Speaker 1: which rests on the principle of quantum entanglement. All right,
• 25:04
  Speaker 1: So now we're going to dig into what is quantum
• 25:05
  Speaker 1: entanglement fundamentally, and then we'll come back and explain how
• 25:08
  Speaker 1: you use quantum entanglement to do quantum teleportation to connect
• 25:12
  Speaker 1: your quantum computers on the quantum Internet and play quantum
• 25:15
  Speaker 1: doom with your quantum friends.
• 25:17
  Speaker 2: Oh nice, but that probably would be easier on a
• 25:19
  Speaker 2: classical computer.
• 25:21
  Speaker 1: You can put doom on anything, though, right the day
• 25:23
  Speaker 1: they pour doom to something, that's how you know it's
• 25:24
  Speaker 1: a real computer.
• 25:25
  Speaker 3: Yep.
• 25:26
  Speaker 2: Amen.
• 25:26
  Speaker 1: All right, So what is quantum entanglement? And this is
• 25:29
  Speaker 1: again something you hear a lot about in the Internet,
• 25:32
  Speaker 1: and I know people are confused about because I get
• 25:34
  Speaker 1: lots of emails from people saying like, why can't you
• 25:37
  Speaker 1: use quantum entanglement to transmit information faster than light, and
• 25:39
  Speaker 1: you can't. And we'll talk about why that is. But
• 25:42
  Speaker 1: you should also understand the quantum teleportation is not faster
• 25:44
  Speaker 1: than light. It's slower than light transmission of quantum information.
• 25:49
  Speaker 1: But before we get to that, let's understand what is
• 25:51
  Speaker 1: quantum entanglement. Quantum entanglement has to do with the superpositions
• 25:55
  Speaker 1: we talked about earlier, the probabilities for various outcomes. So
• 25:58
  Speaker 1: let's say we have, instead of just one particle that
• 26:01
  Speaker 1: can be spin up or spined down, say we have
• 26:03
  Speaker 1: two electrons in California. Each one can be spin up
• 26:06
  Speaker 1: or spin down. So how many possible states can they
• 26:09
  Speaker 1: be in. Well, there's four. There's plus plus, plus minus,
• 26:13
  Speaker 1: minus plus and minus minus, right, so there's four possible states. Cool.
• 26:18
  Speaker 1: And if you just like scrambled the electrons, they can
• 26:20
  Speaker 1: be in any of those states with equal probability. Cool.
• 26:22
  Speaker 1: But let's say we've done something clever. We're an experimentalist,
• 26:25
  Speaker 1: and we've prepared these electrons in such a way that
• 26:28
  Speaker 1: there's a constraint on them, like they have to have
• 26:30
  Speaker 1: opposite spins. And this isn't so hard to do. If
• 26:33
  Speaker 1: they come from some state that has a total spin zero.
• 26:36
  Speaker 1: The universe conserves angular momentum, and so when you create
• 26:39
  Speaker 1: these two electrons, their spin has to add up to zero.
• 26:42
  Speaker 1: It's not so hard. And so if you do that,
• 26:44
  Speaker 1: it means that only two of the states are possible,
• 26:47
  Speaker 1: the one that is plus minus or minus plus the
• 26:49
  Speaker 1: plus plus state and the minus minus state no longer allowed.
• 26:53
  Speaker 1: So we've crossed two of the states off the list,
• 26:55
  Speaker 1: and boom, those two particles are now entangled. Why do
• 26:59
  Speaker 1: we say they're entangled because their faiths are connected? Right?
• 27:02
  Speaker 1: If one is plus, the other one is minus. If
• 27:04
  Speaker 1: one is minus, the other one's plus. And this is
• 27:06
  Speaker 1: not some mystical thing where like you force one particle
• 27:09
  Speaker 1: to be minus and it reaches out through the universe
• 27:12
  Speaker 1: and makes the other one plus. It's just that you
• 27:14
  Speaker 1: have a list of options, and that list is limited,
• 27:16
  Speaker 1: and in every possible outcome they have the opposite spin.
• 27:20
  Speaker 2: I'm keeping track of, like how complicated all of these
• 27:23
  Speaker 2: steps are. So you said it's pretty easy to get
• 27:26
  Speaker 2: an electron that's entangled, so that one is plus and
• 27:29
  Speaker 2: one is minus. What does pretty easy mean? Do you
• 27:32
  Speaker 2: have to like go into the lac after spending billions
• 27:35
  Speaker 2: of dollars, or is this something that can happen in
• 27:37
  Speaker 2: a lab on a UC campus.
• 27:40
  Speaker 1: This happens all the time, like every time a photon
• 27:43
  Speaker 1: turns into an electron and a positron. Those are entangled,
• 27:47
  Speaker 1: like it's constantly happening all of the time, and it's
• 27:50
  Speaker 1: not actually that hard to do in the lab. The
• 27:52
  Speaker 1: thing that's tricky to do in the lab, and the
• 27:54
  Speaker 1: thing that's important is separating those two and maintaining their entanglement.
• 28:00
  Speaker 1: You create those particles, they're entangled, and it's a really
• 28:02
  Speaker 1: cool state because it's not yet determined. Right, they could
• 28:05
  Speaker 1: be plus minus, so they could be minus plus. But
• 28:07
  Speaker 1: then you could separate the particles. You can say, i'm
• 28:10
  Speaker 1: gonna take particle B and i'm gonna drive it to Virginia.
• 28:13
  Speaker 1: I'm gonna leave particle A in California. They're still entangled, right,
• 28:17
  Speaker 1: And then if I measure particle A when it's in
• 28:19
  Speaker 1: California and I get plus, then I know instantly what
• 28:23
  Speaker 1: particle B in Virginia has to be. Because they're entangled.
• 28:26
  Speaker 1: The thing that's hard is keeping them entangled, because to
• 28:30
  Speaker 1: keep them entangled, you have to avoid them interacting with
• 28:32
  Speaker 1: anything else. Like these electrons, they like to interact with stuff.
• 28:35
  Speaker 1: You put them in a box, they'll interact with the box.
• 28:37
  Speaker 1: You put them on a truck, they'll interact with a truck.
• 28:39
  Speaker 1: So keeping these particles in that state while separating them
• 28:42
  Speaker 1: means isolating them from everything else, because if they touch
• 28:45
  Speaker 1: or interact with anything else, then they get entangled with
• 28:47
  Speaker 1: that thing, or they get entangled with you. And now
• 28:50
  Speaker 1: you were part of that quantum entanglement state to do
• 28:53
  Speaker 1: the things that we want to do in a minute
• 28:54
  Speaker 1: to transmit information, and we need them entangled with each
• 28:57
  Speaker 1: other and with nothing else. And that's where the sort
• 28:59
  Speaker 1: of onto magic comes from. Right, these two particles are
• 29:02
  Speaker 1: now really far apart. They can be a kilometer apart,
• 29:05
  Speaker 1: a light year apart, and they both maintain the uncertainty
• 29:08
  Speaker 1: of being in plus minus or minus plus. Then you
• 29:11
  Speaker 1: measure one of them, you get a minus boom. The
• 29:13
  Speaker 1: other one is a plus. You know it, it's gone
• 29:16
  Speaker 1: from uncertain to certain. That's the incredible thing about quantum entanglement,
• 29:21
  Speaker 1: so that you can maintain the connection across distances, that's
• 29:24
  Speaker 1: the non local part of quantum mechanics.
• 29:26
  Speaker 2: Can we dig in a little bit more about how
• 29:28
  Speaker 2: you make them not interact with anything. Do you use
• 29:31
  Speaker 2: like electric fields to hold them in the center of
• 29:34
  Speaker 2: a box?
• 29:34
  Speaker 1: Electric fields are an interaction?
• 29:36
  Speaker 2: Oh man, yeah, exactly what do you do?
• 29:41
  Speaker 1: It's very hard. I mean, with the simplest way you
• 29:43
  Speaker 1: can think about it as a thought experiment. It's like
• 29:45
  Speaker 1: you're out in space. You have a photon. It turns
• 29:48
  Speaker 1: into an electron and a positron, and they're going in
• 29:50
  Speaker 1: opposite directions already naturally, right, Like if it had a
• 29:53
  Speaker 1: lot of energy, then that energy is going to get
• 29:55
  Speaker 1: transmitted to those particles. They're just going to fly apart,
• 29:58
  Speaker 1: and so along the way they're not they interact with
• 30:00
  Speaker 1: anything if it's really empty, and so they'll get further
• 30:03
  Speaker 1: and further apart and still stay entangled. So on Earth,
• 30:05
  Speaker 1: of course, it's much more complicated, and people have all
• 30:09
  Speaker 1: sorts of tricks for keeping these things separated and keeping
• 30:12
  Speaker 1: them isolated. It's not easy. It depends a lot on
• 30:15
  Speaker 1: the details of the quantum system exactly the particles. We
• 30:18
  Speaker 1: can dig into that in a future episode. I think
• 30:20
  Speaker 1: that's a cool idea, but it's not easy. Right. The
• 30:22
  Speaker 1: particles like to interact with everything else. And to decohere,
• 30:26
  Speaker 1: this quantum state is very very fragile.
• 30:28
  Speaker 2: All right, So that is really awesome. You mentioned that
• 30:31
  Speaker 2: this can't be used for faster than light communication. Could
• 30:35
  Speaker 2: you dig into that a little bit more.
• 30:37
  Speaker 1: Yeah, it sounds like you should be able to use
• 30:40
  Speaker 1: it for faster than like communication because there is something
• 30:43
  Speaker 1: non local and instantaneous happening. Particle a's in California, particle
• 30:47
  Speaker 1: b's in Virginia. Both of them are maintaining their superposition.
• 30:50
  Speaker 1: Both of them could still be plus or still be minus.
• 30:52
  Speaker 1: The entanglement just says they have to be opposite. Both
• 30:55
  Speaker 1: of them could still be plus or minus. Right, I
• 30:57
  Speaker 1: make a measurement in California, I get plus instantly know
• 31:01
  Speaker 1: that you would get a minus if you measured yours
• 31:03
  Speaker 1: in Virginia. So there is some sort of instantaneous across
• 31:07
  Speaker 1: space and time thing happening there, which is very very cool,
• 31:10
  Speaker 1: and it sounds like you should be able to use
• 31:12
  Speaker 1: that for faster than like communication. And a lot of
• 31:14
  Speaker 1: people write it and say, well, what if Daniel measures
• 31:17
  Speaker 1: his and Kelly is watching, and so she knows, and
• 31:20
  Speaker 1: you have a series of these things and Daniel measures
• 31:22
  Speaker 1: them at a certain time, and Kelly is watching the
• 31:24
  Speaker 1: pattern or something. It feels like you should be able
• 31:26
  Speaker 1: to maybe use that for faster than like communication. The
• 31:29
  Speaker 1: problem is if I measure mine in California and I
• 31:32
  Speaker 1: get plus, I know that you're going to get a minus,
• 31:35
  Speaker 1: but you don't know that. The Only thing you can
• 31:37
  Speaker 1: do is look at your particle and measure it, and
• 31:40
  Speaker 1: you don't know if it's collapsed or not. You can't
• 31:42
  Speaker 1: tell that it's collapsed. I know that it's collapsed, but
• 31:44
  Speaker 1: there's nothing about the particle itself that shows you that
• 31:47
  Speaker 1: it's collapsed. You can measure it and get a minus. Cool,
• 31:50
  Speaker 1: but you don't know if you got a minus because
• 31:51
  Speaker 1: I already collapsed it, or because it was not collapsed
• 31:55
  Speaker 1: and you collapsed. It's no like your particle has been collapsed.
• 31:58
  Speaker 1: Light that goes on. There's no way to manipulate these things.
• 32:01
  Speaker 1: And I also can't change it. It's not like I
• 32:03
  Speaker 1: can say, oh, I have a plus, I'm gonna flip
• 32:05
  Speaker 1: it to a minus to make Kelly's go the opposite.
• 32:07
  Speaker 1: And as soon as I've measured mine, I break the entanglement.
• 32:10
  Speaker 1: Right it's over. It's interactive with something that was a
• 32:13
  Speaker 1: one time deal. So in science fiction novels where they
• 32:16
  Speaker 1: have like entangled particles and they put one on a
• 32:18
  Speaker 1: ship and they take them to Alpha's centauri and then
• 32:19
  Speaker 1: they can use it as the basis of some answerable
• 32:21
  Speaker 1: technology where they do FTL communication. Yeah, that's pure nonsense.
• 32:25
  Speaker 1: It's fun. I'd love it, but it doesn't work.
• 32:27
  Speaker 2: Okay, so it can't be used for helpful communication. But
• 32:30
  Speaker 2: does the bit flip at a rate that's faster than light?
• 32:35
  Speaker 2: So you bring them to opposite sides of the universe,
• 32:37
  Speaker 2: do they communicate faster than light?
• 32:40
  Speaker 1: Great question, Yes, but I wouldn't say bitflip. So the
• 32:43
  Speaker 1: collapse is instantaneous, right, If I measure mine in California,
• 32:47
  Speaker 1: then instantaneously yours collapses faster than light.
• 32:50
  Speaker 2: Okay. Wow.
• 32:51
  Speaker 1: Yeah, and that's weird and that's cool. And that's the
• 32:53
  Speaker 1: thing about quantum mechanics that we call non local, right,
• 32:56
  Speaker 1: there's something global that's happening there, and people who've heard
• 32:59
  Speaker 1: of Bell's experiment. Bell's experiment proves to us that it's
• 33:02
  Speaker 1: not like one particle was always plus and the other
• 33:04
  Speaker 1: one was always minus. We just don't know it. It
• 33:07
  Speaker 1: means that this uncertainty is real, that they really do
• 33:09
  Speaker 1: maintain the possibility of both outcomes until you do measure it.
• 33:13
  Speaker 1: Bell's experiment proved that there's no like hidden information there
• 33:17
  Speaker 1: that determines the outcome. It really is uncertain or at
• 33:20
  Speaker 1: least and this is important, but it proved that there's
• 33:22
  Speaker 1: no local hidden information. Quantum mechanics has to be non
• 33:26
  Speaker 1: local in some way either. It really is probabilistic, and
• 33:30
  Speaker 1: it maintains these probabilities and collapses instantaneously across space time
• 33:34
  Speaker 1: when one of them is measured. So you should really
• 33:36
  Speaker 1: think of it as like not two particles but one
• 33:38
  Speaker 1: big quantum state. You collapse it anywhere, the whole thing
• 33:41
  Speaker 1: collapses or there are some other crazy theories about global
• 33:45
  Speaker 1: quantum information, you know, like super determinism or whatever that
• 33:49
  Speaker 1: we can get into another time. But you know, the
• 33:51
  Speaker 1: way most people think about it is that it does
• 33:54
  Speaker 1: collapse instantaneously across space and time, which is crazy. But
• 33:57
  Speaker 1: you can't use it to transmit information because you can't
• 34:00
  Speaker 1: control it. Right. You can ask it, you can query it,
• 34:03
  Speaker 1: you can collapse it. I can't even tell whether you've
• 34:05
  Speaker 1: collapsed it or not. And you can't tell whether I've
• 34:07
  Speaker 1: collapsed it or not.
• 34:08
  Speaker 2: Okay, so it's not useful for faster than light communication,
• 34:12
  Speaker 2: but it is useful for quantum teleportation. So after the break,
• 34:18
  Speaker 2: let's jump back up a level to quantum teleportation and
• 34:20
  Speaker 2: try to understand that. All right, we're back. So we
• 34:40
  Speaker 2: now have a firm understanding of quantum entanglement. Maybe we
• 34:45
  Speaker 2: have a firm understanding, and then we have two quantum
• 34:47
  Speaker 2: computers and we want them to be able to communicate
• 34:50
  Speaker 2: with quantum teleportation. Yes, tell us some more about how
• 34:52
  Speaker 2: that works.
• 34:53
  Speaker 1: Right, So remember the problem we want to solve is
• 34:55
  Speaker 1: I have my electron. It's in some state, maybe it's
• 34:58
  Speaker 1: like seventy thirty plus or minus or whatever, and you
• 35:00
  Speaker 1: have an electron in Virginia, and I want to put
• 35:02
  Speaker 1: your electron in the same state as my electron, and
• 35:04
  Speaker 1: I don't want to collapse it, and I also don't
• 35:06
  Speaker 1: want to put in a truck and drive it across
• 35:08
  Speaker 1: the country. How do I get that quantum information without
• 35:11
  Speaker 1: collapsing it and make your electron have it? Right? And
• 35:14
  Speaker 1: so the way we do that is through quantum entanglement,
• 35:17
  Speaker 1: because I can interact with my electron without collapsing it
• 35:20
  Speaker 1: if I use with another quantum particle. So if I
• 35:23
  Speaker 1: touch the electron, or if I poke it with something
• 35:25
  Speaker 1: classical that can't be in a superposition, it will collapse
• 35:28
  Speaker 1: the electron. But if I let that electron interact with
• 35:30
  Speaker 1: some other quantum thing that can be in a superposition,
• 35:33
  Speaker 1: it'll get entangled with that quantum thing. So I have
• 35:36
  Speaker 1: my electronics in the special state. I bring in another particle,
• 35:40
  Speaker 1: and I have those two interacts somehow, and now they're entangled.
• 35:43
  Speaker 1: You have the particle we want to copy and some
• 35:45
  Speaker 1: other particle entangled with it. Now if I planned ahead
• 35:48
  Speaker 1: and had entangled this other particle with a third particle
• 35:52
  Speaker 1: that we then sent to Virginia, we'd be ready to
• 35:55
  Speaker 1: do quantum teleportation. So here's the setup. I have the
• 35:58
  Speaker 1: original source particle I want to copy, and a pair
• 36:01
  Speaker 1: of particles that are entangled with each other but separated,
• 36:04
  Speaker 1: one in California and one in Virginia. I entangle my
• 36:08
  Speaker 1: California particle with the source particle without breaking the entanglement
• 36:13
  Speaker 1: because it's a quantum particle, and so the entanglement just spreads.
• 36:16
  Speaker 1: It doesn't break like it would if it interacted with
• 36:18
  Speaker 1: a classical object or with the whole environment. So I
• 36:21
  Speaker 1: have my California end of our entangled particle pair, and
• 36:25
  Speaker 1: now I've entangled that with the source particle I want
• 36:27
  Speaker 1: to copy, and I can see what happens to the
• 36:30
  Speaker 1: California end of the entangled pair. They can use the
• 36:33
  Speaker 1: information in that new special particle. I can read that
• 36:36
  Speaker 1: off and send you some information. I can email it
• 36:39
  Speaker 1: to you, or I can send it to be a
• 36:41
  Speaker 1: carrier pigeon or whatever some slower then like process, because
• 36:45
  Speaker 1: everything is slower than night. I send you that information,
• 36:48
  Speaker 1: and there's a recipe for using that information to copy
• 36:51
  Speaker 1: the state of my particle onto your electron. I'm telling
• 36:54
  Speaker 1: you what you have to do to your end of
• 36:56
  Speaker 1: the California Virginia entangled pair to make it a quantum
• 37:00
  Speaker 1: copy of my original source particle. So, to summarize, we
• 37:04
  Speaker 1: entangled two particles, separate them while keeping them entangled, entangle
• 37:08
  Speaker 1: my California end of it with the source particle, read
• 37:11
  Speaker 1: off some information about that, and send it to you,
• 37:14
  Speaker 1: so you know how to manipulate your Virginia end to
• 37:16
  Speaker 1: make it a copy of my source particle.
• 37:19
  Speaker 2: Okay, so you have something going on in your computer
• 37:22
  Speaker 2: where you've got entangled cubits, Yes, and you send me
• 37:26
  Speaker 2: an email with instructions for how to do that on
• 37:28
  Speaker 2: my computer. Yes exactly, and now my computer has the
• 37:32
  Speaker 2: same entanglement stuff going on as your computer.
• 37:35
  Speaker 1: Yes exactly. There's a lot of little bits that we've
• 37:38
  Speaker 1: skipped over because the math is a little complicated. But
• 37:41
  Speaker 1: the crucial thing to understand is that I've avoided collapsing
• 37:44
  Speaker 1: my cubit by interacting with a quantum particle, which now
• 37:47
  Speaker 1: stores the information from it. And I can extract that
• 37:50
  Speaker 1: information from my quantum particle and send it to you,
• 37:53
  Speaker 1: so you can reverse the process. If we have kept
• 37:56
  Speaker 1: our entangled pair nicely entangled, you can prepare some fond
• 37:59
  Speaker 1: of part of in that state, have it interact with
• 38:01
  Speaker 1: your electron, and then your electron will be in the
• 38:04
  Speaker 1: same state as my original one was. And so this
• 38:07
  Speaker 1: is what quantum teleportation is. It's a way to interact
• 38:10
  Speaker 1: with the quantum objects, extract their information without collapsing it,
• 38:13
  Speaker 1: encode it into something that we can transmit across the
• 38:16
  Speaker 1: world or whatever, and then reverse the process.
• 38:19
  Speaker 2: But when your quantum particle entangles with an electron in
• 38:23
  Speaker 2: your computer, and then you look at what the quantum
• 38:25
  Speaker 2: particle is doing, so that you can tell my computer
• 38:28
  Speaker 2: what to do. When you look at your quantum particle
• 38:30
  Speaker 2: because it was entangled, doesn't it mess up the system?
• 38:33
  Speaker 1: It does actually mess up the system. And so when
• 38:36
  Speaker 1: you copy the state, it destroys the original state. So
• 38:39
  Speaker 1: the electron that I had in California is no longer
• 38:42
  Speaker 1: going to be in that state that we both wanted.
• 38:44
  Speaker 1: So I extract that information, I send it to you.
• 38:47
  Speaker 1: You use that to create the quantum state over there
• 38:49
  Speaker 1: in Virginia. But there's a no cloning theorem that says
• 38:52
  Speaker 1: that you can't extract that information without also destroying it.
• 38:55
  Speaker 1: But here we are extracting it in such a way
• 38:57
  Speaker 1: that we can recreate the state in Virginia. Yes, we've
• 39:00
  Speaker 1: destroyed the state of the California electron. So I'm not
• 39:03
  Speaker 1: like just emailing you a PDF where like I also
• 39:05
  Speaker 1: still have it. I have to like shred that PDF
• 39:08
  Speaker 1: somehow and send it to you so you can recreate it.
• 39:11
  Speaker 2: So the teleportation, and maybe this is where we discovered
• 39:14
  Speaker 2: that teleportation actually wasn't a great term for this, But okay,
• 39:17
  Speaker 2: so the teleportation is actually just that you've used entanglement
• 39:22
  Speaker 2: to figure out what's happening with another electron. You're sending
• 39:24
  Speaker 2: me that information and you are like teleporting it by
• 39:27
  Speaker 2: email quote unquote, and that's where the teleportation is happening.
• 39:31
  Speaker 1: Yeah, it's very equivalent to saying, like, hey, Kelly, I
• 39:34
  Speaker 1: built a really cool Lego house over here, and I'm
• 39:37
  Speaker 1: going to send you the recipe to do so. I
• 39:39
  Speaker 1: need to like tear apart my Lego house so I
• 39:41
  Speaker 1: can keep track of exactly how you're going to build it.
• 39:43
  Speaker 1: Then I'm email you the recipe and you guys are
• 39:45
  Speaker 1: going to build the same Lego house over there. I
• 39:48
  Speaker 1: had to destroy my Lego house to develop the recipe,
• 39:50
  Speaker 1: and I just emailed it to you, or I send
• 39:52
  Speaker 1: it to you via mail or whatever. But now you
• 39:54
  Speaker 1: have the recipe to create exactly the same thing. And
• 39:57
  Speaker 1: this is tricky only because these are quantum particles and
• 39:59
  Speaker 1: it's not to read them off and to create these states.
• 40:02
  Speaker 1: But this essentially is quantum teleportation. And I'll kind of
• 40:05
  Speaker 1: argue the teleportation it's not a terrible name for it.
• 40:07
  Speaker 1: I mean, if the Star Trek teleporter is scanning you
• 40:10
  Speaker 1: and reading the quantum state of all your particles and
• 40:12
  Speaker 1: then beaming that information to another machine that can reverse
• 40:15
  Speaker 1: that process, then Yeah, that's kind of what we're talking
• 40:17
  Speaker 1: about here.
• 40:18
  Speaker 2: So everything we've just talked about sounds pretty complicated. Can
• 40:22
  Speaker 2: you give me some situations where you would want to
• 40:25
  Speaker 2: go through that process? Like, why would you create something
• 40:27
  Speaker 2: in one computer destroy it just so you can create
• 40:29
  Speaker 2: it on another computer. Couldn't you just create it and
• 40:32
  Speaker 2: the second computer from scratch without making it on the
• 40:36
  Speaker 2: other one first?
• 40:37
  Speaker 1: Yeah? Maybe, but perhaps it's the outcome of a very complicated,
• 40:41
  Speaker 1: very expensive quantum computation, you know. And like, let's say
• 40:45
  Speaker 1: I have a quantum supercomputer and you ask me to
• 40:47
  Speaker 1: do some calculation about your tapeworm simulation.
• 40:50
  Speaker 2: I don't know, you have my attention.
• 40:53
  Speaker 1: I do it for you, and I want to send
• 40:54
  Speaker 1: you the result, right, I want to use the quantum
• 40:57
  Speaker 1: Internet to send you this quantum answer to your quantum
• 40:59
  Speaker 1: could computer from my quantum computer. And yeah, you could
• 41:02
  Speaker 1: recreate it, but it might be really really slow, and
• 41:04
  Speaker 1: so might well just copy the answer in the same
• 41:07
  Speaker 1: way that your computer can calculate your taxes much much
• 41:09
  Speaker 1: faster than you can. And you might think, well, why
• 41:11
  Speaker 1: do I need that? I can just do it myself. Yeah,
• 41:14
  Speaker 1: but you might as well skip ahead and get the
• 41:15
  Speaker 1: answer so in that way, the quantum information here represents
• 41:18
  Speaker 1: the results of a quantum computation, which could be extraordinarily valuable, right,
• 41:22
  Speaker 1: and so you might want to save that. And people
• 41:25
  Speaker 1: thought about ways to build super powerful quantum computers by
• 41:28
  Speaker 1: tying together quantum bits across the quantum cloud, right the
• 41:33
  Speaker 1: way you like, we make very powerful computers by spreading
• 41:36
  Speaker 1: information and computation across them. You ask Amazon to do
• 41:39
  Speaker 1: a complicated calculation, it doesn't just run in a one computer.
• 41:42
  Speaker 1: It runs on ten fifty one hundred, so that you
• 41:44
  Speaker 1: get the answer faster. In the same way, maybe you
• 41:46
  Speaker 1: take a big quantum problem, you break it into pieces.
• 41:49
  Speaker 1: Each quantum computer does a piece of it, and then
• 41:51
  Speaker 1: they want to send the answer back to some central
• 41:53
  Speaker 1: node which puts it together to get the final answer.
• 41:55
  Speaker 1: That requires a quantum internet of quantum computers that can
• 41:59
  Speaker 1: send quant states back and forth to each other. And
• 42:02
  Speaker 1: so that's why this is a stepping stone to some
• 42:05
  Speaker 1: future awesome globally linked quantum computer.
• 42:08
  Speaker 2: And so where are we now? Has somebody recently done
• 42:10
  Speaker 2: this quantum teleportation thing?
• 42:12
  Speaker 1: Yeah, so people have been working on this for a while.
• 42:14
  Speaker 1: And the bit that we talked about the quantum entanglement
• 42:16
  Speaker 1: and sending information usually requires really specialized hardware. Keeping our
• 42:21
  Speaker 1: two particles entangled is hard because we have to keep
• 42:23
  Speaker 1: them isolated from any classical object. And what happened recently
• 42:27
  Speaker 1: is a lab at Northwestern in northern Chicago managed to
• 42:30
  Speaker 1: do quantum teleportation over normal fiber optics. Right, So usually
• 42:34
  Speaker 1: like keeping that information pristine and clean is very very hard, Right,
• 42:39
  Speaker 1: you have specialized hardware to transmit this information because it
• 42:42
  Speaker 1: has to be just right. But they were able to
• 42:44
  Speaker 1: use fiber optic cables that were thirty kilometers long that
• 42:47
  Speaker 1: already also had normal Internet traffic, so like people randomly
• 42:51
  Speaker 1: emailing and texting pictures of their cats and whatever, and
• 42:54
  Speaker 1: they were able to send this information to do quantum
• 42:56
  Speaker 1: teleportation across this noisy, totally and fiber optic cable. And
• 43:02
  Speaker 1: so that was the excitement recently about the quantum Internet,
• 43:04
  Speaker 1: is that we went from like you need specialized, dedicated
• 43:08
  Speaker 1: hardware to do it for a single electron, to like,
• 43:10
  Speaker 1: oh no, we can do it over long distances using
• 43:13
  Speaker 1: standard equipment that already exists.
• 43:15
  Speaker 2: But you're not sending entangled electrons through fiber optics. You're
• 43:20
  Speaker 2: just sending instructions through fiber optics that then set up
• 43:23
  Speaker 2: the next computer on the other side.
• 43:25
  Speaker 1: Is that right, Yes, that's exactly right.
• 43:27
  Speaker 2: Okay, still totally awesome. I just wanted to make sure
• 43:29
  Speaker 2: I was understanding all right, awesome.
• 43:31
  Speaker 1: Yeah, And so this is the first demonstration of quantum
• 43:34
  Speaker 1: teleportation of entangled photons through busy optical fibers that are
• 43:38
  Speaker 1: also carrying conventional telecommunications traffic. So, you know, it brings
• 43:42
  Speaker 1: us a step closer. It's not like we have the
• 43:45
  Speaker 1: quantum Internet. It's not like you can log on right
• 43:47
  Speaker 1: now to the quantum Internet and do your quantum taxes
• 43:50
  Speaker 1: or anything like that. But you know, this is an
• 43:52
  Speaker 1: important step forward in making this realistic because if we
• 43:55
  Speaker 1: want to build a bunch of quantum computers and connect them,
• 43:57
  Speaker 1: it'd be nice if we could use standard equipment to
• 44:00
  Speaker 1: do so and not have to build a whole separate
• 44:02
  Speaker 1: quantum Internet. So it's cool, it's like, very experimentally awesome.
• 44:06
  Speaker 2: Taxes are so complicated it wouldn't surprise me if next
• 44:09
  Speaker 2: year we need to be doing our taxes on quantum computers.
• 44:12
  Speaker 2: But I hope we're not getting there.
• 44:14
  Speaker 1: Yeah, well, you should think about whether you want to
• 44:15
  Speaker 1: pay your taxes or not pay them or both.
• 44:18
  Speaker 2: Whoa, I know which one I'd rather do. But on
• 44:21
  Speaker 2: the other hand, I really like my government services, so
• 44:25
  Speaker 2: I feel complicated and.
• 44:26
  Speaker 1: I like not being in jail.
• 44:28
  Speaker 2: Yeah, me too, Me too. There's a lot of things
• 44:30
  Speaker 2: that would be hard to do from jail, like this podcast.
• 44:34
  Speaker 1: Actually that might be possible. We'll find out maybe.
• 44:36
  Speaker 2: Yeah.
• 44:37
  Speaker 1: So the quantum Internet is a real thing, right. Quantum
• 44:39
  Speaker 1: computers are real and they're awesome, not always in the
• 44:42
  Speaker 1: way people say they are. They're not the multiverse, but
• 44:44
  Speaker 1: they are a new way to do computation. And quantum
• 44:47
  Speaker 1: teleportation is a real thing. It's not faster than light,
• 44:50
  Speaker 1: it's not Star Trek, but it is a way to
• 44:52
  Speaker 1: transmit quantum states across vast distances, which is very cool.
• 44:56
  Speaker 1: Bring them together and you get the quantum Internet. Quantum
• 44:59
  Speaker 1: computers connected through quantum teleportation to do massive quantum problem solving.
• 45:04
  Speaker 1: I think it's pretty cool.
• 45:05
  Speaker 2: The future is now, and so.
• 45:07
  Speaker 1: I hope I didn't throw too much of a wet
• 45:09
  Speaker 1: blanket on the quantum Internet. There is really a lot
• 45:12
  Speaker 1: of awesome physics happening there. And if one day we
• 45:14
  Speaker 1: do have very powerful quantum computers. They may be able
• 45:17
  Speaker 1: to solve problems that do stomp us today. So I
• 45:20
  Speaker 1: look forward to the first time an episode of this
• 45:22
  Speaker 1: podcast is released on the quantum Internet.
• 45:24
  Speaker 2: Well, you are now a member of the Wet Blanket Club.
• 45:26
  Speaker 2: But it's going to be a while before your president.
• 45:29
  Speaker 2: But I enjoyed spending this time with you.
• 45:32
  Speaker 1: Are you dictator for lives that hot works?
• 45:33
  Speaker 2: Yeah? Yeah, that's right, and Zach's first husband of the Dictator.
• 45:41
  Speaker 1: I'll start as as secretary, work my way up.
• 45:43
  Speaker 2: Oh right, good luck?
• 45:44
  Speaker 1: All right, thanks everybody for listening. I hope we didn't
• 45:46
  Speaker 1: entangle your minds at least not too much.
• 45:56
  Speaker 2: Daniel and Kelly's Extraordinary Universe is produced by iHeartRadio. We
• 46:00
  Speaker 2: would love to hear from you, We really would.
• 46:02
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• 46:05
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• 46:07
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• 46:10
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• 46:14
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• 46:20
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• 46:30
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