Speaker 1: Welcome to tech Stuff, a production from iHeartRadio. Hey there,
Speaker 1: and welcome to tech Stuff. I'm your host, Jonathan Strickland.
Speaker 1: I'm an executive producer with iHeartRadio. And how the tech
Speaker 1: are you. Today's tech stuff tidbits is what's a cubit? Well,
Speaker 1: he's this little orange guy who jumps up and down
Speaker 1: a pyramid like structure while trying to avoid snakes. He
Speaker 1: also has a habit of cursing. Wait, sorry, I'm being
Speaker 1: told by the Yeah, okay, no, sorry, guys, got that
Speaker 1: totally wrong. That's Cubert. A cubit is something else entirely,
Speaker 1: I know cringe jokes. Also, Originally I thought maybe I
Speaker 1: would go a different way with that, and I would
Speaker 1: talk about cubits being a unit of measurement used to
Speaker 1: build arcs in Biblical times. But you see that joke
Speaker 1: about what a cubit is, Well, it existed in two
Speaker 1: states simultaneously, but ultimately, when it came time for me
Speaker 1: to choose which joke to use, it had to collapse
Speaker 1: into a single state, which is the Cubert joke. And
Speaker 1: that whole bit about collapsing into a single state. I
Speaker 1: can't promise it'll make more sense later. But I can
Speaker 1: promise we're gonna talk about it all right. So to
Speaker 1: understand what a cubit is. Cubit, by the way, actually
Speaker 1: stands for quantum bit. Well, it stands to reason that
Speaker 1: first we have to understand what a bit is. Now.
Speaker 1: Way back in nineteen forty eight, in the early days
Speaker 1: of computer science, a man named Claude Shannon published a
Speaker 1: work titled A Mathematical Theory of Communication. Shannon was mentored
Speaker 1: by a guy named Van Var Bush that I really
Speaker 1: need to dedicate at least one episode, but probably multiple
Speaker 1: episodes two at some point, very important person in tech
Speaker 1: in general played a large part in some really historic
Speaker 1: and sometimes terrible technological events in history. I have actually
Speaker 1: dedicated an episode to Claude Shannon in the past, so
Speaker 1: if you go and do a search in the Tech
Speaker 1: Stuff archives, you'll find an episode just about him. But anyway,
Speaker 1: in this work, Shannon proposed a basic unit of information,
Speaker 1: a binary digit or bit. The bit exists in one
Speaker 1: of two states. It is either a zero or a one.
Speaker 1: Shannon's work goes into a lot of other territory with
Speaker 1: a fascinating treatment on communication theory that fundamentally changed how
Speaker 1: communication engineers think about the subject, but it gets really
Speaker 1: technical really quickly, and I honestly would have to study
Speaker 1: it for days to feel comfortable even talking about it
Speaker 1: in a way where I didn't feel I was getting
Speaker 1: it all wrong. So rather than blindly lead you into
Speaker 1: a discussion that I would likely get completely wrong, we're
Speaker 1: going to move on to something else that's equally complicated.
Speaker 1: But for our discussion, the important thing is the bit
Speaker 1: zero or one. You can think of it as no
Speaker 1: or yes, or off or on. It's as basic as
Speaker 1: you can get. By grouping bits together, you can express
Speaker 1: more complex information. So one bit has two states. If
Speaker 1: you have two bits, you have four states. You can
Speaker 1: express zero, zero, zero, one, one, zero, and one one.
Speaker 1: With three bits, you've got eight possible states. Four bits,
Speaker 1: you've got sixteen possible states. By the time you get
Speaker 1: up to eight bits, it's two hundred and fifty six states.
Speaker 1: So you see how adding one bit to a string
Speaker 1: doubles the number of states that string can express compared
Speaker 1: to when it was one bit fewer. All right, So
Speaker 1: then we get into an era in which computer scientists
Speaker 1: start working with this concept in a practical way, and
Speaker 1: after a while, computer scientists begin to agree on other stuff,
Speaker 1: like the idea of eight bits representing a bite. This
Speaker 1: wasn't always the case. There were some who proposed six
Speaker 1: bits rather than eight, et cetera. But we're gonna skip
Speaker 1: way ahead and talk about processors for a moment. Processors
Speaker 1: take data in the form of bits and execute operations
Speaker 1: on that data to create output, like mathematical operations, and
Speaker 1: those operations come from a program. The program is really
Speaker 1: just a set of instructions that the processor is meant
Speaker 1: to follow while working with this data, and it generates
Speaker 1: some sort of result. And a lot of factors determine
Speaker 1: how fast the processor is, like how much data it
Speaker 1: can process within a given amount of time. Now, generally speaking,
Speaker 1: the more bits the processor can accept at once, and
Speaker 1: the higher the clock speed of the processor, which really
Speaker 1: means the number of operational steps the processor can complete
Speaker 1: in a second. Well, then the more powerful the computer
Speaker 1: is and the faster it will solve problems to a point,
Speaker 1: but there are some computational problems that are much harder
Speaker 1: to solve than others, and even a fast processor can
Speaker 1: get bogged down by them and it becomes impractical or
Speaker 1: even impossible to compute that problem. So, for example, there's
Speaker 1: the famous traveling salesman problem, which is a type of
Speaker 1: NP hard computational problem. The NP stands for nondeterministic polynomial time.
Speaker 1: But we don't need to really get into all of that.
Speaker 1: The traveling salesman problem presents a list of cities and
Speaker 1: it asks the question, what is the shortest route starting
Speaker 1: from the salesman home city to each of these cities
Speaker 1: and then back to home without visiting a city twice.
Speaker 1: What's the shortest route that you can take? Well, for
Speaker 1: a computer to solve that question, it would need to
Speaker 1: calculate the route using every possible combination, and that route
Speaker 1: obviously gets more complicated as you add more cities to
Speaker 1: the list, and a sufficiently large list would keep a
Speaker 1: computer busy for a really long time, like months or years,
Speaker 1: or decades or centuries, depending on the complexity of the problem.
Speaker 1: So that's an issue, right. You cannot easily solve this
Speaker 1: class of computational problems with a classical computer. But what
Speaker 1: if you could design a computer that could potentially solve
Speaker 1: this problem in a flash by essentially calculating every route simultaneously.
Speaker 1: Now we're getting into the possibilities offered up by quantum
Speaker 1: computing and the cubit. The cubit is a quantum bit,
Speaker 1: and like a bit, it can have a value of
Speaker 1: zero or one, though we represent them asket zero and
Speaker 1: cut one states. But I'm gonna leave it there because
Speaker 1: describing representation and notation in an audio only podcast is futile.
Speaker 1: I'd be like, okay, then you have a little squiggly line.
Speaker 1: None of that would make any sense, so we're gonna
Speaker 1: leave it there for now. But here's the thing. A
Speaker 1: cubit can also have both values at the same time
Speaker 1: and technically all values in between, and hold those values
Speaker 1: in superposition until the system collapses and the cubit assumes
Speaker 1: one or the other states. And which one it assumes
Speaker 1: is based on probabilities. So it may be that it's
Speaker 1: a fifty to fifty, which means half the time the
Speaker 1: cubit would be a zero and half the time the
Speaker 1: cubit would be a one. It doesn't have to be
Speaker 1: fifty to fifty, however, so this is one of those
Speaker 1: weird quantum effects that Schrodinger wanted to poke at with
Speaker 1: his cat thought experiment see Early quantum physicists theorized about
Speaker 1: superposition that certain quantum stuff can hold multiple states simultaneously
Speaker 1: until something disturbs them, at which point they collapse into
Speaker 1: a single state. Schrodingsher's absurd example was that of a
Speaker 1: box containing a kitty cat and then a time release
Speaker 1: method of making the kitty cat unalive, as you might
Speaker 1: say on TikTok. But this time release method would be unpredictable.
Speaker 1: It might trigger five minutes in or it might hold
Speaker 1: off for hours. So you've got this box, thirty minutes
Speaker 1: have passed. Is the cat alive or dead? Well, if
Speaker 1: we were to think of the cat as being in
Speaker 1: a quantum state, you could argue the cat is both
Speaker 1: alive and dead at the same time. And it's only
Speaker 1: when you open the box and observe the system do
Speaker 1: the possibilities collapse into one reality. And in this reality
Speaker 1: we're gonna say the kitty cat lives. Because I've always
Speaker 1: hated this thought experiment, Shrodinger was trying to say this
Speaker 1: idea was ridiculous, And of course, on the classical level
Speaker 1: of cats and cars and cigar boxes and stuff like that,
Speaker 1: all the stuff we can see and touch and manipulate,
Speaker 1: it is absurd. But at the quantum level, it holds
Speaker 1: true quantum effects can exist in two states simultaneously. It's wild,
Speaker 1: but it is true. So if you could harness something
Speaker 1: that works on the quantum level, like electrons, for example,
Speaker 1: and you could use some feature of electrons such as
Speaker 1: their spin where they spin up or spin down, you
Speaker 1: could use that to serve as a cubit, And in
Speaker 1: a properly isolated system, you could use a bunch of
Speaker 1: cubits to run algorithms specifically designed for quantum systems, and
Speaker 1: these cubits, by occupying all states simultaneously, could generate all
Speaker 1: possible outcomes in the time it would take to solve
Speaker 1: you know, the hardest one. Another way to think about
Speaker 1: it is that if you have a bite, that is
Speaker 1: eight bits that are strung together, you can have one
Speaker 1: of two hundred and fifty six values. If you have
Speaker 1: eight q bits, then you can have all two hundred
Speaker 1: and fifty six values at the same time, at least
Speaker 1: until you measure it, at which point it loses coherence
Speaker 1: and settles into a single value and becomes one of
Speaker 1: the two hundred and fifty six possibilities. But while in
Speaker 1: superposition it's all of them. However, it gets weirder, and
Speaker 1: I'll explain after we come back from this quick break. Okay,
Speaker 1: what could be weirder than superposition? Well, I haven't talked
Speaker 1: about entanglement yet. All right. For this explanation, let's imagine
Speaker 1: that we have two cubits, and we'll say our cubits
Speaker 1: are in the form of electrons and their direction of spin,
Speaker 1: so the electrons can spin either up or down. And
Speaker 1: let's say I've prepared the cubits so that right now
Speaker 1: they're both spinning down, and we'll call that the zero
Speaker 1: state versus the one state for this example, So both
Speaker 1: cubits are spinning in the zero state, cubit A and
Speaker 1: cubit B. Now, if I apply an oscillating magnetic field
Speaker 1: to cubita a magnetic field at a frequency proportional to
Speaker 1: the energy difference between cubit a's zero state and its
Speaker 1: one state, I can actually rotate cubit A. I can
Speaker 1: rotate its spin. And the presence of cubit B complicates
Speaker 1: things a little bit, because these two cubits create their
Speaker 1: own magnetic fields. I have to take into account cubitb's
Speaker 1: magnetic field as I apply this external magnetic field to
Speaker 1: rotate cubit A. But I can do that and then
Speaker 1: move Cubita into superpositions. So now Cubita is both zero
Speaker 1: and one at the same time. All right, Now let's
Speaker 1: move on to cubit B. Now, remember I started with
Speaker 1: both cubits in the zero state. They're both spinning down. Well,
Speaker 1: now I apply the magnetic field I would need to
Speaker 1: use to rotate cubit B if Cubita were still in
Speaker 1: the zero state, except Cubita isn't in the zero state anymore.
Speaker 1: Or rather it is, but it's also in the one
Speaker 1: state because I've put Cubita into superposition. Well, now, when
Speaker 1: Cubita is in zero, cubit B will rotate to one
Speaker 1: because of this oscillating field I've put on it. But
Speaker 1: when cubit A is in the one position, cubit B
Speaker 1: will stay in the zero state because I would have
Speaker 1: needed to use a different frequency in my magnetic field
Speaker 1: to make cubit be rotate if Cubita is in the
Speaker 1: one state, so cubb also goes into superposition. If Cubita
Speaker 1: is zero, then the rotation worked, and if cubit B
Speaker 1: is one, then the rotation didn't work. But Cubita is
Speaker 1: technically both, so the rotation both did and didn't work
Speaker 1: at the same time. The two cubits are entangled, and
Speaker 1: the state of one depends upon the state of the other,
Speaker 1: and they're opposite. Even if we were to separate these
Speaker 1: two cubits and we were to put them at either
Speaker 1: end of the universe, they would remain entangled as until
Speaker 1: we observed them or something else disturbed them, at which
Speaker 1: point we would lose coherence and the state becomes either
Speaker 1: zero or one, and the state of the other one
Speaker 1: would be the opposite of the one you observed, even
Speaker 1: if it's on the other side of the universe. So
Speaker 1: if you went to one end of the universe and
Speaker 1: someone went to the other end of the universe with
Speaker 1: the other one, you've got Cubita, they've got cubit B.
Speaker 1: You observe Cubana, you see that it's zero. You know
Speaker 1: that cubit B was a one crazy, even though they
Speaker 1: were all the way across the universe from each other.
Speaker 1: Einstein hated this. By the way, he couldn't get the
Speaker 1: math to prove that it didn't work, but he hated
Speaker 1: the idea, and he called it spook key action at
Speaker 1: a distance in quantum computing entanglement creates a really counterintuitive opportunity.
Speaker 1: You can code for two bits that have unknown but
Speaker 1: opposite states, Like you don't know if cubita is a
Speaker 1: zero or a one, but you do know that whatever
Speaker 1: it is, cubit b is the opposite. And that might
Speaker 1: not sound useful at the surface level, but it opens
Speaker 1: up opportunities that simply aren't possible with classic computers. So,
Speaker 1: for a subset of computational problems, the ones that are
Speaker 1: really hard for classic computers, a quantum computer with sufficient
Speaker 1: cubits and the right algorithm you need both can turn
Speaker 1: what would be a massive challenge into a metaphorical piece
Speaker 1: of k Now. For other computational problems, a quantum computer
Speaker 1: would be no better than a classic computer, and depending
Speaker 1: on the number of cubits the quantum computer has at
Speaker 1: its disposal, it might be equivalent to a really, really
Speaker 1: bad classical computer. The thing is, some interesting and potentially
Speaker 1: dangerous problems might be simple for a quantum computer to unravel,
Speaker 1: problems like classic encryption techniques. So a typical approach to
Speaker 1: encryption involves using mathematical operations and a really large number
Speaker 1: to scramble a message. Only someone with the proper key,
Speaker 1: can reverse this process to get the unscrambled message and
Speaker 1: to guess the value of the key that unscrambles everything
Speaker 1: would take a really, really long time. How long depends
Speaker 1: upon the strength of the encryption, but if we're talking
Speaker 1: like military grade, you could be there forever. But with
Speaker 1: a quantum computer that has a lot of cubits and
Speaker 1: the right algorithm, you could potentially solve for the encryption
Speaker 1: key in just a few minutes. This is why quantum
Speaker 1: computers could spell the end of our current methods of encryption.
Speaker 1: A person with access to a sufficiently powerful quantum computer
Speaker 1: and that pesky algorithm would then hold the skeleton keys
Speaker 1: that fit all the digital encrypt locks that are out there,
Speaker 1: which is kind of spooky. And for that reason, researchers
Speaker 1: are working on quantum encryption methods that can stand up
Speaker 1: to quantum computers that you know, uses a different approach
Speaker 1: to scramble those messages so that they stay safe from
Speaker 1: all but the intended recipient. Also, I started talking about
Speaker 1: Claude Shannon as the guy who popularized the term bits,
Speaker 1: although Shannon himself gave credit to John Tukey, whom Shannon said,
Speaker 1: use the term bits in a memo, but Shannon's is
Speaker 1: the first earliest you know, published work to use the
Speaker 1: term bits. But who coined cubit, Well, that would be
Speaker 1: Benjamin Schumacher, who submitted an article titled quantum Coding in
Speaker 1: nineteen ninety three to Physical Review. The article actually published
Speaker 1: in nineteen ninety five. Schumacher is a theoretical physicist. By that,
Speaker 1: I mean he's a real physicist. He's not theoretical, but
Speaker 1: he works in theoretical fields, including quantum information theory. He
Speaker 1: did for quantum information theory what Shannon did for communications theory,
Speaker 1: with about half a century separating the two, which is
Speaker 1: pretty darn cool. And so that's the basics on cubits.
Speaker 1: And if you were to come up to me and
Speaker 1: say do you understand this? Do you understand why it happens?
Speaker 1: I would honestly tell you no. But then when we
Speaker 1: get down to quantum effects, that's just the truthful answer
Speaker 1: for everybody. We can say that definitely happens, that we
Speaker 1: have the experimentational evidence to show that this does happen.
Speaker 1: Why it happens, that's a question that we're still trying
Speaker 1: to answer, and maybe we'll never come up with it,
Speaker 1: but it's really cool to look into it. Now, if
Speaker 1: you'll excuse me, I have a game of Hubert to
Speaker 1: get back to tech Stuff is an iHeartRadio production. For
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