SIO372: Quantum Entanglement In The Real World

Transcript

This transcript was generated automatically and may contain errors — the audio is the record.

0:00:16 Thomas: And welcome to Serious Inquiries Only, this is episode 372, I'm Thomas, and we are headed back into the quantum realm for this one, I hope you heard the quantum computing episode with Anne a back, that one ended up being so kind of, I don't know, intimidating that I we both thought it'd be great to take a step back a little bit and go for more basics first, and here's what I love about this recording, look, if you re someone who has listened to me for a while, I think one thing that would be fair to say would be you never really know where the conversation is going to go exactly.

And that's what I love. And this one, so I wanted Ann to kind of teach us about some basics, quantum entanglement, which is so fascinating, and non-locality. Stuff that basically everything that makes Deepak Chopra think that there's some magical power behind the universe, all of that stuff, demystify it as much as possible. That's what we do here. But here's the thing. It also ends up being a really interesting look into the practicalities of kind of running a lab with this stuff, you know? It's

0:01:20 Thomas: These thought experiments about entangled particles and all that crap, what I love about this is we really drilled down into like, okay, but how, like how physically do you do that and how would it work? And it just, I don't know, I feel like it's a conversation I've never heard before and it was so much fun.

So with that said, I want to get you on over to Anne, and mind you, I can't give, I wish I could give Anne more credit, but Anne needs to remain anonymous for job reasons, so I can't tell you more about Anne. Just suffice it to say, Anne is somebody whose work is in the quantum realm, does this stuff for her job. She's an expert and a lot of fun to talk to.

Other thing I'll say before we get to it is please support the show at patreon.com/seriouspod. It's it's so important, and in addition to getting ad -free episodes, you don't have to hear those damn auto -ads coming in if you're signed on to the Patreon feed. In addition to that, you'll get those monthly bonuses, and I'm thinking the movie format's going to work great.

We are scheduled to record on Armageddon for our first, I guess we'll say, seriously awful movies, or SAM, maybe, yeah, scientifically awful movies, I don't know, who cares, for our first movie thing. It's going to be really fun.

Armageddon is a just one of my all-time favorite just bad movies, I don't even, not even a fan of like watching bad stuff, but Armageddon is so good bad and just silly that I've watched it twice in my life, which is enough for me for bad movies, that's more than I can say for most bad movies.

I don't like watching bad movies but this one I'm actually, I'm looking forward to watching again, and we're going to break that down with, of course, astrophysicist Brian, so we can see what they got right.

0:03:06 Thomas: What Michael Bay, if right there. So make sure to jump on patreon.com/seriouspod on the second tier and above, will be coming to you, well, before the end of the month is all I can say, for sure before the month, because it is July's bonus. All right, right. So please do so if you are a patron. Thank you kindly, dearly. I love you so much. Hope you enjoy all this stuff. And with that said, let's get get over to our discussion with Anne on non-locality, entanglement, Schrodinger's cat, all that good stuff. I'm joined by top secret government agent, government stooge, uh, who can't tell you more about Ann, because you work for the top secret deep quantum research field branch of the government that's doing all the quantum, I think, right?

0:03:46 Anne: The deep state.

0:03:47 Thomas: Uh. You'll remember Ann from quantum, uh, which was a really really fascinating episode. And I'm hoping you're back to, we should, we kind of, I think we started with something way more complicated than we should have maybe. And then we're going to go backwards a little bit and start, I won't say simpler, but start at a more early level, maybe of understanding.

0:03:47 Anne: Yeah.

0:04:10 Anne: We're gonna go for a more reductionist approach this time, well.

0:04:13 Thomas: Today we're going to talk about quantum entanglement and non -locality because that's super cool. And I'm pretty sure it means that magic is real and we get faster than light communication, right? All the healing, we got everything from that, right? Didn't it pretty much crack everything we could want to do?

0:04:31 Anne: If there's something you can't explain, you just go quantum, and quantum's non-local, so ergo, Harry Potter. That's

0:04:39 Thomas: Yeah, it's not, hey, meet local quantum in your area, you get some non-local, I don't know, it's long distance quantum telephone fees. Yeah, why are we taking this on? Are you saying that there's some people who maybe don't possibly grasp this correctly? Oh.

0:04:57 Anne: In my line of work, um, an experimentalist, this means that you have to buy stuff quite often, um, of the things that I have to buy, uh, well, sources, so light sources, and those are crystals, um, this was also what I wrote my thesis on, was quantum solid crystals, and my YouTube search has been fucked ever since, um.

0:05:17 Thomas: But so, but that's a real thing, so like for reals, crystals? Oh. Okay. So that's actually important to note, so like quantum crystals is at least a thing, but then some got a hold of that concept and why don't you explain what is a real quantum crystal, what does that actually do? Wow.

0:05:20 Anne: Yes. Oh.

0:05:30 Anne: Yeah, and In the context of what, you, what I'm attempting to look for now, I mean, these are things that exist, they're fairly common-ish, and it's what we call a spontaneous parametric down-converting crystal. And what that does is you hit it with some laser light of some energy, and It'll take take that photon of energy X and produce two daughter photons that the sum of their energies will be X.

0:06:06 Thomas: And we can see their gender specifically, wow. We check what bathroom they're allowed to use in like fucking deep south, and then that's how we know which yeah

0:06:09 Anne: They're always daughters. Yeah, of And what clothes they're supposed to wear. And since they're daughter photons, they have to be really nice. And yes.

0:06:20 Thomas: There are only two photon gender, well maybe there's only one, actually I'm only hearing about daughters, there's one photon gender, okay, so this is a thing that you're trying to do for just like for funsies, or do, what do you do with this? Okay.

0:06:36 Anne: Well, well, what do with it is I to distribute entanglement, of my goal here is I to be able to have something that I know, or at least reasonably know, is a single photon, and I take another single photon, and then I want to entangle those photons with each other, and then I want to have somebody else join in on the entanglement fun so I can distribute my entangement to them, to another lab, and hopefully to a across the whole network. Yeah.

0:07:08 Thomas: Oh and then you're just doing the quantum entanglementy stuff just for just for to be cool, you know, I'm realizing as you're talking, a fun game would be for a lay person, now I have the benefit of you that you're not full of shit on some level, but if I was, if you were just a person, I was just a person, I would wonder how far you'd have to get into it before I would know whether or not you were just making stuff up. Cause like everything you just said, I'm like, uh-huh, I just grab, I buy crystals, and then I just, with my friends, we, you some quantum distribution to whatever, and it's like, ah, okay, that's that's why this is so tricky. I really see why every single pseudoscience thing is just, yeah, quantum, cause it's, it's like, fuck, okay, now I don't know, all right, it must be real.

0:07:14 Anne: Yep. Yeah.

0:07:54 Anne: Kind of hit it right on the head, because like I said, when I go and I look for crystals, like something, if I'm just looking on Amazon for a book, I'll get like down one page of real stuff stuff, and then like maybe when I hit page two, I start to get like weird things in there, and sometimes I'll even come across something where I'm like, is this full of shit or not, I actually don't know. Oh.

0:08:19 Thomas: Yeah. Boy, don't know if you – like how much of your work you're allowed to explain, plain, but like, what are you, what Are you doing? Is it all you're saying you do experiments? Is that what it mainly is?

0:08:32 Anne: I mean, I'm, I firmly in the field of, um, like to twist knobs and see what happens, is the way that I work, a lot of learn by doing, um, yeah, like part of, um, a uh-ish um initiation, or or initiative effort, I'm in these meetings, I should know, um, is

0:08:38 Thomas: Okay.

0:08:52 Thomas: Yeah, you're not very good. I can tell already. You're not good at the corporate speak office lingo bullshit. I'm not either. I hate it to death, but you know, my wife can code switch because she has that job. So she can do, we're all going to touch base on the circle back email of quantum healing, but no, yeah, that's that. So that tells me you probably probably do know what you're doing because people actually like, you know, want to do stuff.

0:09:12 Anne: God. An I have like an action item to circle back on the, oh. It.

0:09:18 Thomas: All right. Action item for our podcast is circle back on telling me what the hell you do, but you're okay. So you're just messing around. You get to mess around with cool, fun, amazing science stuff for your job, which is fucking awesome.

0:09:30 Anne: It's great when I don't have to spend the whole day buying stuff, um.

0:09:33 Thomas: Love buying stuff. That's another benefit. Favorite things. You have my dream job. How can I take your job? No, I don't have enough education. Okay. So you just entangle a bunch of stuff. Are you doing with it then? Just seeing if they, you get along, maybe want to get married when fall in love, you know.

0:09:50 Anne: Yeah, we have a whole language that we speak in, so it's always Alice sends a photon to Bob, and maybe sometimes there's a Charlie, and I've decided what D is, I've excited, D should be Debbie, so um. It's just easier than point a point b so We like to set up nodes our where we have, you know, like Alice, you maybe entangles two photons or Alice has an entangled source. She sends a photon to Bob. Has his own entangled resource. They entangle those together. Maybe Charlie makes a measurement on those two photons.

0:10:03 Thomas: All right.

0:10:21 Thomas: We're going to have to step way back because I already. Okay, Okay. So we'll get there. So what is entangling?

0:10:22 Anne: Yeah. Yeah. Yeah. We should probably go too far. So where you have a property that is, say, shared or communicated or common, correlated, You know, there's a lot of different sort of nuances to these terms that two separate particles can share, and then they can be spatially separated and still share this property. So that if we measure one, so if Bob makes a measurement, Alice's measurement will be correlated or reflect what Bob measured.

0:10:49 Thomas: Hmm.

0:11:12 Thomas: So I thought Bob and Alice were the photons. That's silly me. I was naming the photons, but we're talking about who has them. Who's like in possession of the photons? Like they have them in their pockets.

0:11:18 Anne: Yeah. Everything's statistical, so we're talking about millions of photons, so that's way too many kids to name. Like Duggar territory.

0:11:29 Thomas: Having just watched that horrifying documentary, I don't want to think about that. Yeah. What have they done to those poor photons? This is also the thing we need to take care of on this. No, okay, so questions then. When you say a particle, what are, what are the limits of like, what is a thing that can become entangled, and are this sort of the limitations of that? Like, what, what kind of characteristics or whatever can be entangled? Wow.

0:11:32 Anne: Did I. I'm not sure really what the is, but like that you can have, say, a memory of sorts where you can entangle like an ensemble of a gas. I'm Not sure exactly how many atoms we're talking about, if we're Talking about thousands or millions. Generally, when I'm talking about a particle, like I really mean like one atom. Or, a photon, a atom. An

0:12:11 Thomas: Right. Well, a one atom, okay, so not a, not necessarily just a photon. What?

0:12:25 Thomas: So what are the limits of that? Can I have a, like, can I entangle my shovel with your, you know, like what, how big can you get? All.

0:12:33 Anne: So the problem that you have when you have entanglement is that it's a quantum state, which means that it is really easy to collapse it, and anything interacting with it collapses it. So the bigger your of things that you have that you want to entangle, the higher your probability that something's going to interact with it and collapse it all. So like any sort of, say if a photon, um, is traveling through space and its electric field, uh, another photon's electric field they have interacted.

0:12:43 Thomas: Right.

0:12:58 Thomas: Define for us, for the normies, what what is an interaction? What would do it?

0:13:17 Thomas: Oh, Okay. Like they fly next to each other and they're like, "Hi, hello, we, oh, now we got to assign, we" got assigned numbers to our, uh, you, characteristic momentum and, and whatever the other characteristics are that can be entangled, that kind of thing. Yeah.

0:13:18 Anne: Um, nope. Now we're done. Yeah. Yeah, and, and one thing that does come up a lot in a lot of, you know, people peddling stuff is that, that idea of the, the observer effect that Oh, if you don't observe it, then the cat's both alive and dead. And it's like, and now it's a measurement is much more loose than that. You do not need a conscious observer, it's

0:13:39 Thomas: Yeah. Right.

0:13:51 Thomas: Consciousness. That's the biggest place where it seems like people misunderstand this, and and I sure wish somebody, back Mr. Quantum whoever invented, invented it, should have thought of this ahead of time and not made it like an observer. Whoever said observer, I feel like that's bad, you know?

0:14:06 Anne: And in, this is kind of a problem with, I think, language in the way that we talk, because I, I come from the world of condensed matter physics, and we use language all the time where we're like, the electron sees the lattice. And that's, I mean, it's easy for us because, you way that you're thinking about it, but when that gets written down and someone else reads it, exactly, then,

0:14:17 Thomas: Yeah. Yeah.

0:14:27 Thomas: Deepak Chopra reads it and then like at the same time, I totally get it, the struggle, because if me if I'm wrong, but like when you're dealing with this kind of stuff that's just so not intuitive, intuitive, you're often just grasping at like, okay, what's a word that we can say so that we at least know kind of what we're describing to each other as scientists, you know, like, is that part of the problem?

0:14:47 Anne: And when you want to simplify it because you're trying to communicate with each other in the a simple way in a field that has a lot of technical terms, you don't really want to introduce a new artificial technical term, kind of shorthand. And also when you are in grad school and you're doing this for five years straight and the only people you're talking to are other people who are doing it, you just tend to fall into habits.

0:15:13 Thomas: Yeah, for Sure. So the thing we're talking about the, so I asked the question of, what counts um, as an interaction? And talking about Schrodinger's cat thing, we're talking about like anything that would collapse, would that? So then, then we know what happened to the cat, right, did

0:15:27 Anne: Yeah, so that could be like, you in the case of Schrodinger's cat, you it was set up. You have an atom and decays and it has a daughter particle, as they always say, which in this case was a helium. It was an alpha particle, the

0:15:41 Thomas: They actually do this to A cat? Is that or the thought experiment? Oh,

0:15:45 Anne: Thought experiment, but They always call it a daughter article, particle. So the, the this case is an alpha particle, so it's a it's a daughter particle, uh, of Helium, exactly.

0:15:45 Thomas: Okay, Right, Fucking Quantum patriarchy, hard at work, can't

0:15:56 Anne: Yeah, you look into any of those people you'll find a whole bunch of shit, um, sad, but hey, you

0:16:01 Thomas: We have one scientist, give us one fucking scientist that isn't shit, please, in our history, is there anybody, all

0:16:08 Anne: Know, from what I found, Faraday was actually okay. I don't know, who knows, maybe if you dig into them enough

0:16:11 Thomas: Cool, I mean wasn't he designing cages and stuff though, who is he putting in those cages?

0:16:17 Anne: Gonna take a whole podcast to find out, yeah.

0:16:19 Thomas: Are the questions, yeah, that's What, no one's asking, who was in the, hashtag, who was in the cages, Faraday, anyway, okay, we can't get distracted. So there was a helium atom, you're setting it up, helium

0:16:20 Anne: Yeah.

0:16:30 Anne: So, so in that case, um, as the helium atom, you know, away from its, its parent atom, and you, whether or not the helium atom decayed, whether or not it tunneled out of the atom, that's based on a, you, quantum mechanical effect, uh, that's probabilistic by nature, it's a superposition of two states, whether the atom decayed or whether the atom didn't, but an interaction with that helium atom that's ejected, um, could be a thermal photon from outside, that could just be your black body radiation from the fact that it's room temperature in the box, and that photon touches that helium atom, and now the wave function's collapsed, the measurement is not limited to somebody opening the box.

0:17:20 Thomas: Right.

0:17:20 Anne: And consciously seeing it.

0:17:20 Thomas: Right, right, oh, well, That's the question, is it wasn't like it was a quantum cat, I think that's how it gets misunderstood a lot, you, the cat itself isn't like a quantum thing, it's just, there would, the, in the thought experiment, there's like a mechanism that would kill the cat, and that's, you know, something that hasn't collapsed yet, allegedly, okay.

0:17:38 Anne: Yeah, And the original thought experiment was the measurement of the daughter photon, whatever that measurement was, so, so they made it up to be, yeah, you have a, you know, some sort of helium, you, atom reader, and that's your measurement device, that is what kills the cat, or not. If

0:17:46 Thomas: Okay, But We don't know whether it's killed until, yeah, man, this whole Schrodinger's cat thing really does, I really see why Schroedinger's was like, as we covered last time, Schroedinger was like, see, this is why this is all fucking nonsense, you guys, and then it turned out like, I don't, I don't know, is it, doesn't turn turn out that, like, yes, actually the cat might not be either dead or alive.

0:18:19 Anne: You could truly isolate the system, would be, I mean, I don't want to say impossible, but it would be extraordinarily too difficult for me to imagine how you could isolate something as macro as a cat from the whole rest of the universe in order to do it.

0:18:38 Thomas: Oh, well, wait, do you have to isolate the cat? Because I thought the whole thing was like I just described. It was more about the, whatever the thing that it's measuring being isolated, right?

0:18:47 Anne: But If you have the cat outside of that isolation, then you just have the thing, so the cat's clearly alive because it's outside your measurement device, then you just have a dial that's on or off, and that's boring, so it's much more interesting to have a cat in there now

0:19:00 Thomas: Well, how does that, oh man, here I thought, I thought I sort of understood it and now I don't. So the, no,

0:19:06 Anne: That the cat is kind of superfluous, he was just doing that to be cute, well,

0:19:10 Thomas: I know, but it's, I feel like it's important to kind of help understand what the the hell is happening? You can't isolate, like what's the cause and effect of what needs to be isolated in order to not have this thing collapse? Like if we have a camera in there on the cat, then we can't do any of this cause it's not isolated.

0:19:27 Anne: Let's see, camera, not in the sense of that we're watching it, it's that if you have, if your quantum state is the, the, the atom, you know, ejecting its, its daughter particle or not, and then the, the measurement that's in question is your controller over whether the vial of poison is opened or not, um, guess you could say, in a way, I suppose it would be fair to say that if you had all of that isolated, then the effects of that poison being released is still in a quantum state, but then we kind of have everything is sort of in a superposition of a quantum state, which I guess it sort of is. So it depends on how comfortable we are with that.

0:20:15 Thomas: Well, shoot. I, this is the kind of thing where I feel like we could spend an hour on this, but also I, I kind of might need to, cause I don't understand what's happening. So is there, okay, okay, the box, what, what kind of box are we, so, like, you've got an atom somewhere and that thing has to be isolated from everything, right? Otherwise it blows the whole game, right, we can't have any, uh, taken of that, or it's collapsed, okay.

0:20:40 Anne: So, so you want it to actually not be measured so that it can still be in a quantum State. So the measurement cannot happen in order for it to still be in a quantum States.

0:20:52 Thomas: But Whatever the measuring, like a hypothetical thought experiment, like, know, poison vial releaser thing is, would that just always collapse it, or can that exist in a way that it's not collapsed?

0:21:04 Anne: The, the release here could not, like, that wouldn't be a collapsible thing, it would just be whatever triggers the release, yeah.

0:21:11 Thomas: Right. Yeah. That's kind of what I meant. So

0:21:12 Anne: So It, so it's, it's just, you, if know you had that, not all, like, if you had just a cat and a window that could or could not release poison gas, and I think this is becoming like a philosophical, semantic argument over what, what is actually the superposition state? Because I think what I would say is that if the cat and the poison are not also included in the isolation, then the cat being alive or dead is not in a superposition, because if it's in the real world, we are clearly, the world is measuring the cat, so the cat has a clearly defined state.

0:21:59 Thomas: Interesting.

0:22:00 Anne: That's what I would say. But on the other hand, I do think there's an argument to be had to say that you could say that the effect of it releasing the poison is in a quantum state, and that quantum state would directly affect the aliveness and deadness of the cat.

0:22:15 Thomas: Yeah. I thought that was the whole thing. I thought That was the only thing we're talking about.

0:22:19 Anne: So that's fair to say, even if the cat's not in an isolation, you could say that, yes, it's in a superposition of dead or alive. But what I would argue there, and I'm not saying this is wrong or fun to think about, we're kind of all in a superposition of dead or alive then, aren't we? And, you know, that could just be the way the world works. And, we don't have any control over that, so that's fine.

0:22:35 Thomas: Okay. Wow. And I want to understand this better, but I feel like I'm running a bit of a wall with literally, I don't understand how this could be even hypothetically constructed in a way that would make sense. But okay, well, I'll uh, I'll try to, you know, leave that aside. That's the thing we're talking about, we're taking about that collapsing, um, is uh, uh, decaying. Is that like a half -life thing, or is that something else? I didn't know. Adam's just like decayed. They, they get a little moldy when you don't put them in the fridge, or oh.

0:23:07 Anne: A half-life thing, which means it's good game that will never get its sequels.

0:23:10 Thomas: So That's where, like, some amount of them just statistically, probability-wise, atoms are, I don't know, it's been too long since I've taken in these high school classes, but

0:23:20 Anne: One's based on quantum tunneling. So you have an energy barrier that's holding your atom together, but there is some statistical probability that you can have something tunnel through that energy that's what a decay is.

0:23:37 Thomas: And that's how we're taking this ship into hyperspace. Okay. It's another one of those things where, yes, it works on this tiny, tiny, tiny quantum level -y thing, but we're not getting a whole Millennium Falcon to be that, right?

0:23:40 Anne: Yes.

0:23:52 Anne: No. No. That's kind of one the hearts of quantum locality, non-locality, is that you, you can have spatially separated quantum that share a quantum state, and Bob can measure his particle and Alice measures hers instantly, at the same time or directly, like a fraction of a second after Bob does, no matter how far away they are separated in space, their measurements are going to be correlated, which

0:23:52 Thomas: Okay.

0:24:23 Thomas: It has to be around the same time? I thought it was like you could do it whenever.

0:24:25 Anne: No. No, it doesn't have to be yeah. You can, well, I mean, say I, when we're talking thought experiments, you can do it forever. In the real world, no, because yeah

0:24:26 Thomas: Oh, okay. Because you just can't keep it in that superposition without it getting messed up, collapsed.

0:24:37 Anne: You have to keep it in a superposition and this is the whole issue of having quantum memories, don't last that long and you have coherence times and all that stuff of the real world that messes this up, but yeah

0:24:40 Thomas: Right so As a hypothetical, we're gonna say we can just, for fun, keep something in a superposition for indefinitely, just so we can understand it yeah Okay, we'll pretend we can do that. So, okay, let's get back on whatever kind of quantum track we had. So I think I was asking you, like, how things get entangled and what could get entangled, exactly, if I remember correctly, although my quantum memory already collapsed, so, um,

0:24:56 Anne: Let's just pretend we can do that yeah non True, it only lasts like, like a microsecond, they are a way of generating entangled pairs, um not the only way, yeah

0:25:17 Thomas: So the crystals, so we're on crystals, so that's, uh, crystals are a way of entanglement stuff possibly pairs, oh The mirror experiments, is it that kind of thing where it's like, we've, if we have one photon and it took two paths, oh, is that a way for entangling to happen, or is that just a different thing, those that's right, okay, I'll

0:25:37 Anne: Oh, when you have one photon that could take two, two different paths, um, now that would be single photon, um that's not entanglement but what you can do with that, so, so what you have is when you have the photon, it can go in, um, put it through beam splitter, it can can go either on path A or path B. And and what we know is that actually it's a superposition of both path A and path B, because if we recombine it, yeah.

0:25:54 Thomas: Splitter oh that's superposition yeah Yeah, okay, so that's different, that's distinct from entangling, sorry, I messed up my thing, sure Superposition and entanglment are different things, right? Okay.

0:26:10 Anne: Well, you can use that to entangle. They are different things, but they're used together a lot.

0:26:23 Thomas: Sure, sure, so one, one photon can be be in superposition. And that's, that means it's like, it's taking both paths until we kind of collapse it and measure it. Right. And it can interfere with itself. And that's how we know it's at, it'S literally taking both paths until we measure it, it is not just like A, yeah. And that's so it's so cool. Um, but okay. Apologies. I got mixed up, but maybe that'll be helpful to, um, at least hear how I was mixed up. Maybe that'll clarify things for other people who are trying to grasp this. So not superposition necessarily, um, then explain how you entangle stuff exactly then, okay?

0:26:33 Anne: Can interfere with itself because, yep. Yep.

0:26:57 Anne: In the case of the crystals that I care about, what do is you have a photon come in and just for the sake of easiness, let's say it's green, it's 500 nanometers. That photon interacts with the of the crystal, the way that the crystal is set up, and it gets absorbed. And then the crystal, it needs to, you to energy conservation. So the crystal emits two 1,000 nanometer wavelength photons. Now, depending on the properties of the crystal, what we have is that since these two photons were created in this process that was conserving a quantity, they can be entangled with each other. They are correlated with each other in terms of like, what I care about is a polarization. So then those two photons come out, and now, depending on the type of crystal it is, they can either have, you know, the the same polarization, or they could have exactly opposite polarizations.

0:27:00 Thomas: Okay. Okay. Right.

0:28:09 Thomas: Okay, is it essentially, and again, just trying to put it in, make sure I don't say anything that's incorrect, but like, we don't have to explain every single thing, essentially, because of, you still following the laws of physics, the laws of conservation of whatever, momentum and and mass and all that crap. Can put a photon in a thing and it can turn into essentially two photons, but they're bound by some rules. Essentially, they can't be like overweight. They're on a diet. They're On Keto. They can only whatever they can only have certain things that wouldn't violate conservation of momentum or energy or something. And therefore, but we don't know what those are. So therefore, they're entangled in that once we measure one, we know like, okay, now we know the other one has to be something, otherwise it would break the rules.

0:28:24 Anne: Yes. I Would say, like, unlike politics, this is a zero-sum game, um, this

0:28:58 Thomas: Okay. Okay. I see. That's really cool. I didn't know a photon could like turn into two photons. Well, I guess anything can fucking do anything these days because of woke left. Taking our, no, I don't know.

0:29:10 Anne: What you get with woke physics. Now we can have one photon deciding to be two photons When

0:29:11 Thomas: Yeah. Ah, I can be a daughter or a son Photon. Photons change their gender at the drop of a hat. Okay, so that's super cool, so you, so, and and as you said, by the way, there's like a zillion different ways to entangle stuff in a zilion different properties, or at least more than one property that can be this the entangled thingy, right? And you're just talking about one that you do with these crystals, okay?

0:29:16 Anne: Yeah. Yeah. You this Is just one in particular, which, which I, you to care about a lot today because I'm trying to buy some, go

0:29:44 Thomas: Is this, like, you're gonna do a like a fundraiser for your healing crystals, and this is an elaborate thing, so help and buy her healing crystals so she can heal her sick grandmother, yeah. Okay, so we've got, we'll establish that, we'll all assume we're following up until then. And then, you know, you're putting one of those daughter photons in a mailbox, you're sending it, sending it via UPS to another lab so that they can, how would you get something far away in that state without just ruining it?

0:29:56 Anne: To GoFundMe Slash Well, you know, in case of photons, you can can send it through the air. So if you are NASA, you care about sending a photon from one satellite to another satellite, and you're just going to do that through the air. You're just gonna send a laser and point it at another, you on another laser. Yeah well

0:30:31 Thomas: And then the key is once you're doing this it's not literally one fucking photon you're sending a beam that's just constantly entangling like a zillion of these things because

0:30:43 Anne: Do send one at a time. Yeah you you can do this with what call free space optics. So you can send from whatever your crystal output, and it goes through the air, and that goes to some microscope objective that's collecting it. I saw an article recently about how quantum LIDAR was going to help self-driving cars, and one, this kind of hits me in a bad way. Because all the stupid car companies bought all the APD companies, and now it's really hard to buy APDs, and they suck.

0:30:45 Thomas: Really, okay, okay.

0:31:17 Thomas: What's The APD, oh

0:31:18 Anne: It stands for avalanche photodiode, yeah, how you detect single photons. It's, now they're all really expensive and annoying, yeah, it does suck, um

0:31:23 Thomas: That sucks, that's sort of like when, when essentially, like, ruined the GPU market, is it like that kind of thing? Yeah.

0:31:32 Anne: Yeah, it's Like, "Oh, thanks, you guys are now mining Bitcoin, now I can't play Half-Life." Yeah.

0:31:32 Thomas: Yeah. Okay, so you can send one, I guess I was thinking like when you send it through the air, isn't that an opportunity, a la what we discussed a second ago, for it to collapse constantly because it might run into something, okay?

0:31:41 Anne: Yeah. You can send Oh Yeah, and that's why you do not get good data rates, which is why using quantum lidar for self-driving cars is a dumb idea, because, um, that's not going to work well.

0:31:59 Thomas: All Right. Well Let be known, we've already learned a lot of things, but one actual tangible thing is that that's a stupid, stupid idea for self-driving cars or whatever.

0:31:59 Anne: Um Don't need to use quantum, there just use regular lasers God, yeah, it's fine, but if you wanted

0:32:09 Thomas: Yeah. She's the regular kind. Yeah, just don't do quantum for one time. Scientists just be like, oh, let's just use a flashlight. We'll just look at something. You don't need quantum entanglement. Okay.

0:32:21 Anne: It Not the solution for everything, because What, what happens when you, when you try to send quantum signals, so you know, in in certainly in the case of of optical signals, when you're working with photons, you sending one photon at a time, but you can do this either free space or you can do it through fiber, um, either way, you're gonna get losses, you're You're going to, you're, yeah, and It's Um I mean Sometimes there are experiments where we get, like, we're not talking about like photons, you're talking about like regular like network traffic, like people are like gigabits or whatever terabits, we're not even talking about like a photon a second, sometimes we're like a proton a minute.

0:32:25 Thomas: Yeah right.

0:32:43 Thomas: Okay, Okay. Packet loss. Like actual energy packet loss.

0:32:58 Thomas: In terms of how fast you're able to do it. Oh, why is it so slow? It's still traveling at the speed of light, isn't it?

0:33:07 Anne: Yeah. Yeah, we just lose a lot, yeah.

0:33:12 Thomas: Oh, okay. So you're sending them at some sort of rate, which I imagine could be quite high, but then it's like, well, we lost fucking all of them. And there's one that goes through. Okay. And is that, I imagine that's going to be a product of what? Like normal stuff, like how long you're trying to send it, and how, you know, like, that'll give it more opportunities to fail, kind of thing, or interact Okay.

0:33:21 Anne: Yep. Yeah. Basically. Yeah.

0:33:32 Thomas: But but you can send it through a cable, because I was gonna say, like, it sounded almost like you needed like a line of sight and stuff to do what you, it seemed like you were saying a minute ago, but what's, what kind of distances are we talking that that could even work, I'm just curious for the free space thing.

0:33:35 Anne: You consider the fiber You're doing free space, uh, Free space, it depends on what your wavelength is and what direction you're going. So if you're, let's say, like, if you're NASA, and you want to do this with, like, your ground station up to your vehicle, that's overhead.

0:33:51 Thomas: Okay. Ground Ground control to Major Tom.

0:34:05 Anne: Yeah. Um, Earth orbit's really not that high, it's like 400 kilometers, um, The air is getting thinner as you go up. And there's some other funky stuff that happens with the atmosphere, but, um, itS not undoable, but you're, you're if you sent just single photons up, you'RE, you 'Re gonna be there for a long time. But if you're have two vehicles that are in space and now they're in vacuum, um, your chances of propagating the signal are significantly better.

0:34:06 Thomas: Got it. Yeah. Uh -huh. Right. Nice.

0:34:32 Anne: Um, then also you have the issue of what, you're doing. Like if you're, if you'RE in low earth orbit, your vehicles are moving really fast and it's going to be kind of hard to point them at each other. If you're up in geo, geo's really, really far away. So yeah.

0:34:39 Thomas: Hmm. Yeah. And that geo is the like, 24 -hour orbit, so you stay up above the same spot on the Earth?

0:34:53 Anne: When I I used to teach, I go -to test question on every single final was, uh, to calculate what geosynchronous orbit is.

0:35:01 Thomas: Like, how far away it is? Or how? Like, like how high up it Is. Oh, okay.

0:35:04 Anne: Yeah. How far away is, yeah. How high up it is. It's like,

0:35:06 Thomas: Because I Always Thought, like, I- I know, my physics professor, high school, he would do the kind of thing where he would give you, like, you know, how long does that take, or set it up in a way where it's not like you don't realize you're talking about geosynchronous and then it's like, oh, god damn it, it's just fucking- it's ah, should have known that right away, okay. So it dependent on stuff we would figure, anyway, like distance and kind of how many other molecules or whatever's Are around that you might run into. Okay. But,

0:35:29 Anne: Yep. Fiber's got its own issues to fiber. You got different, you got different wavelengths that work good in fiber. So wavelengths that worked well in fiber don't work well in air and you Know, different fibers are different, some fibers are faster, um,

0:35:42 Thomas: Okay. Are you able to just, I might be a little, you know, too mechanical or technical, but like, how do you know when you've succeeded?

0:35:54 Anne: It a series of measurements that you can do that you can kind of pick what you want, so Um, So

0:35:59 Thomas: Okay. Let's pretend, Let's make it. Okay, you and I, we're two fucking labs. You're Ann Lab over there. I'm Thomas Lab over here. And we're like, let's, you know, things are going well. We're, we're getting along. We 'Re like, let's entangle some particles, you know, see, let' s take this to the next level. And we've got a, you know, just a fucking cable going from each other, how do we, what do we do? So you've got the- you're the one entangling, I guess, you've got the crystals because you already have them, you know, I would have to go to the store, I don't want to do that, so you got the crystals, you're firing the lasers and putting it through a whatever cable of some kind, whatever that is, how do we know, you know, describe any of that that you think will be helpful for us and how do do we know when we've, we've succeeded?

0:36:39 Anne: The one thing I could do, like, if- so if I, I have some entangled photons and I would like to send you a photon, probably the first thing I want to do is I want to verify that I am indeed sending you a single photon that is correlated with my photon. So what I would do is I would keep one photon and send you the other one. And then we would synchronize our measurement devices and see when we have a coincidence. So when, or

0:37:09 Thomas: Right. Cause when I, cause I'm just getting photons, it's not like these photons are getting blocked or something. It's just, they're losing their entanglement. Right.

0:37:18 Anne: They could just get lost, absorbed, tunnel through the fiber.

0:37:21 Thomas: Well in, Oh, Oh really? In a fire. Well, okay. But I'm assuming

0:37:22 Anne: Yeah. So you can have a loss of, you can just have your photon gets lost. You can have another is generated by scattering. And you could also have a Loss of Entanglement, which we'd probably refer to as a loss in fidelity.

0:37:41 Thomas: Sure. Okay. So I guess what I was trying to get at is if I'm over there, I'm, I're over, you're doing the whole thing. I'm I'm just like telling you, oh God, a photon, you don't know right away if it's an entangled one or do I because entangled ones are somehow the only ones that are even getting to me.

0:37:57 Anne: You would not know that it's entangled. You would just see a click on your detector. Detector, so

0:38:01 Thomas: And even that click means I've fucked it all up, right? Isn't that, isn't the click, like, all right, we've blown it. You're We're alive, I donno, right?

0:38:06 Anne: Click means the cat's Dead, yeah. The first thing you probably want to look for is is coincidences, so like if I measure a photon at time t and you measure a photon at some time t plus x, and we can do that consistently and see a pattern where I keep, keep measuring it and you keep measuring at some set Time away from each other, and then, okay, we're, we're getting started.

0:38:30 Thomas: We're I'm picking up what you're putting down, yeah. Yeah, because, we, okay, are all dealing with probabilities because we could get lucky, right? So it really is like we have to measure it enough, whatever statistically enough times would be for us to say, all right, looks like we've got some good entanglement going here. We're getting along. We're compatible.

0:38:37 Anne: Yeah.

0:38:48 Anne: Well, That wouldn't tell us that it's entangled. That Just means that we're, I'm giving you photons and I'm getting photons, and we are just going to first establish that Because you Also have, you can have losses, and you can also have, um, counts. Sometimes your detector is just going to go click just for the hell of it.

0:39:03 Anne: Um, They do That Yeah, so, so you set it up and you leave that going overnight, and then you come back in the morning, hope your computer didn't crash, um, So Then, then Oh, Yes.

0:38:51 Thomas: Oh, Okay, sure. Jeez, this is so hard to do.

0:39:12 Thomas: Oh, wow. Okay. It was that slow where you're like, fuck. Oh,

0:39:16 Anne: Yeah. These are, these are usually the hours measurements. Okay, so then we're happy. So now what we want to do is see if they're entangled. And the way that we're going to want to be able to do that is maybe see if we have a correlation in the thing that we care about. So then what I'm going to do is I'm gonna set up on my end to measure polarization. And then you're gonna set it up on your end to measure polarization, and then we are going to be the same experiment again. It's going to to be worse because we put more stuff in there Which means More things

0:39:16 Thomas: Okay? Wow. Okay. Oh yeah. Well,

0:39:49 Anne: Are going to get Lost

0:39:49 Thomas: Cause we have to measure that polarization before we go click, right? Cause it doesn't, again, doesn't click collapse everything.

0:39:55 Anne: So what we're gonna, well, and had this discussion a lot at work, um, I think really, I it's, it's polarization measurement itself is what kind of collapses it, so So what we do is we put it through a polarizing beam splitter, and if it's one, if it say H H polarization, it goes one way. If it's V polarization, it goes the other way. You do the same thing.

0:40:06 Thomas: Okay. Okay, all right. So that's what I've gotten over here. Oh, and you, oh, oh that's right. We're creating two. And so you've essentially, and I know this is going to sound so dumb, but it's just really trying to fathom how this works. You've essentially you've got like a fucking cable splitter that That you've got, so like I've got that one end of the cable, the other end you're keeping and you're hooking it up to your polarization checker, measurer, and I've got mine over to mine. And so we've established that we're getting that connection. Question on that, because I didn't, I just assumed that like, forget all the entanglementy stuff. If I, if you were just wiring me photons, I assumed that would be a pretty easy process. But you're saying even that is something where there's not that much gets through?

0:40:19 Anne: Yeah. Mm -hmm. Mm -huh.

0:40:55 Anne: Want to get into it, you're going to have... You got another problem here.

0:40:58 Thomas: You got to call Comcast and be like, Hey, we're fucking it's down again. I'm not getting any photons over here. They're like, Oh yeah, we'll come between 12 and six years from now. And then we're like God damn it.

0:41:08 Anne: Oh, no joke. We have to... Oh, my God. Yeah. I mean, we kind of have to do that with the fiber people.

0:41:12 Thomas: Oh man.

0:41:13 Anne: And, like, we don't ever... like we've measured links of fiber where we don't actually know. The fiber is. Have no idea. Well, like I don't want to say we had no idea, but like, they don't tell us like we, we get a company where the fibre is. Like if we're connecting two different labs, we don't always know exactly where the fibres.

0:41:23 Thomas: Sorry. Don't tell us what, what do you mean? Like where it's physically gone. It could, like you could pick up the, And

0:41:33 Anne: They just, we just call somebody and they make a connection and yeah.

0:41:37 Thomas: You're like, I don't know if you just connected the phone line accidentally or the actual fire, okay. There's A lot Of

0:41:41 Anne: Well, I mean, we know it's a fibre, but sometimes like we're it'll be like, think that this is by train tracks, because sometimes during the day, I get a lot of vibrations on my fiber, and I don't know why. And yeah, yeah, this Yeah, I mean, we're Oh,

0:41:42 Thomas: Oh You can Feel Like physically Feel Does that fuck with the photons

0:42:01 Anne: Yeah. Well, it if you're measuring polarization, they do not like stuff shaking your fiber. Um, yeah, I mean, we live in the real world, in the real world you Literally are calling somebody to go connect Some Fiber

0:42:08 Thomas: Yeah That's What's so funny Boy I, you Know, as much as we talk about all these shrugging your cats and uh, and the hypotheticals and thought experiments, my favorite thing about talking to you is how much you're just like, yeah, and then you gotta call the fucking plumber because the, it's actually the photons clog the toilet and you gotta go, you gotta get a guy out there. They don't do weekends, by the way. And it's a union job, costs a lot. It's good. I believe in a fair wage, but, you know, like quantum plumbers, they cost a lot, it's a barrier. It's a real barrier. We're working on getting more funding for that. Like, there's so much of these like really basic regular world concerns to quantum stuff that I never would have thought of in a million years.

0:42:13 Anne: Yeah Yeah And, and that is kind of part of what we care about in a weird way, is documenting all this weird stuff, because we have a lot of telecom infrastructure in the United States, this Is not true of of other country, but in the united United States, we have a significant amount of telecom infrastructure. And we would like to keep using it. But that means that sometimes we're dealing with a chunk of fiber that was laid down in, I don't know when they invented fiber, the 70s. I have no idea. Don't quote me on that. T want to say it's old and insult people. But like, people who who originally laid it down might not be alive anymore.

0:43:01 Thomas: But Yeah. That's fine. We can insult old people. I

0:43:28 Anne: So we don't always know exactly where it's going, but it's a resource and we want to use it.

0:43:28 Thomas: Guess Thing I know, this may seem weird, but I'm still caught on the fact that like, how does not many photons go through this stuff? We're talking about, forget all the quantum entanglement, just sending photons through a fiber cable. That's not a thing that you can can just do a lot of for some reason, okay.

0:43:51 Anne: Is you want to have a dedicated fiber. Like I said, we have a lot of infrastructure here.

0:43:58 Thomas: We're assuming you and I, we hooked it up, we're good, we got, we just have a cable to each other, like we're two yarn cup things as kids, we're all set.

0:44:06 Anne: Yeah. We that a dark fiber. We have a a dark fiber between us, yep.

0:44:07 Thomas: A Why?

0:44:10 Anne: Because

0:44:10 Thomas: Is it dark, did it kill its father, and then

0:44:12 Anne: No. One else is using it, but but we can pretend like it killed its father, that's fine.

0:44:13 Thomas: Oh, oh, okay, okay, I thought it was, so it's not evil, it's just yeah If No one else, is our exclusive cable that we have how. We can't just send a billion photons through that easily? They all just die? Okay, so that will work.

0:44:19 Anne: Yes. We do, uh, that we do send a billion, um, just that if you send a billion, you might get a million. It

0:44:33 Thomas: Oh, it's that bad. So what is that happening?

0:44:36 Anne: Depends.

0:44:36 Thomas: It's just running into stuff?

0:44:36 Anne: Yeah, it, regular fiber has has about 0.2 dB per kilometer of loss. So that will be maybe tens of thousands of photons just per kilometer that just get lost. Say you're sending a bill. Like, can.

0:44:51 Thomas: Out of how many? I'm literally putting a laser pointer into a cable at this point? I actually don't know. Really?

0:45:00 Anne: So one way to get single photons is actually just to take a laser and attenuate it a lot, lot, so that you have, and usually what you want to do is you want to pulse it, and so, like, you know, you hit it with laser nothing laser nothing laser nothing, and if you want to have good statistics on getting a single photon, then you want to have a probability of about 0.1 photons per pulse. So that means if I'm sin, if I'm pulsing my laser at say 100 megahertz, then I'm going to be getting, um, 10% of that going through.

0:45:37 Thomas: Wow. Okay. We actually do this? This sounds fun. Or does it just require a bunch of expensive equipment that Tesla bought up so we can't do it anymore?

0:45:44 Anne: Just the APDs. Oh my God. They're so hard to buy.

0:45:47 Thomas: Can't get a good Apt these days, I agree, uh, it's the kind of thing where I feel like there's not a lot of tolerance for something being fucked up, like you're dealing with literally the most sensitive kind of measurements and stuff, right, all

0:45:48 Anne: I they're not even really that expensive. They just take forever. That's the hard part. The supply chain is insane. So it's, really just made everything take take months and months and months to get stuff.

0:46:09 Thomas: Right, we'll set that aside, we've got our dark cable, it killed its dad, chopped, we've got that all set up, so you are able, forget the entanglement, you are able to send quite a few photons just normally, you know. I agree, granted we're losing what, 90 percent, a lot, high percentage of them.

0:46:20 Anne: Yeah, we're losing. We're losing a lot like if you're going to send a single photon, you have a certain probability that that photon is just going to go away. It's just going to, you eaten up by the cable. So say you have like a 10 percent chance of it making it through a single photon for normal communication. You're sending so many billions of photons. You don't notice how many need to leave.

0:46:33 Thomas: Okay, mm. Right. Right. Right, but that's because we're not trying to just pulse one at a time.

0:46:51 Anne: But in our case, we only have one. So we, we notice when it goes away. Um, other thing that we're fighting against is the rate at which we can produce the photons is a bit limited.

0:46:51 Thomas: Okay, yeah. Oh, it is, why is that, wow.

0:47:05 Anne: Um just the way that nature has decided to work because it does not care about us. So when When you do, when you have a crystal, the probability of that 500 nanometer photon being downconverted is not a hundred percent.

0:47:13 Thomas: Oh, I see, that's where I got mixed up, because I was like, oh, we're just shining a laser in that cable, I don't know why that's a big deal, no, no, no, you're putting a crystal. And I imagine this is just with Scotch tape, like you've got a crystal Scotch type to the cable and then you're shining a laser on that and you need it to specific law. I'm sure there's some stuff in between to tell whether you're doing anything right, but you need that to specifically take one photon and split it into the two that kind of two that we need, because

0:47:34 Anne: Yeah.

0:47:53 Anne: Yeah. And that, that just happens on the probability. Of the crystal. So that's

0:47:59 Thomas: God, does play dice or whatever with the universe.

0:48:01 Anne: Exactly, it on the physical properties of the crystal and, you It's just inherently a probabilistic thing. So the photons are coming out at random.

0:48:10 Thomas: Yeah, Is that's what I didn't understand, okay, I totally forgot about that, so the end, as you say, you really are just dealing with like one photon a fucking hour actually fitting all these conditions.

0:48:22 Anne: Well, if you get into, if you want to interfere two different photons, like say I have two crystals and I want a photon from each crystal to interfere with each other so that I can entangle the two other

0:48:37 Thomas: Yeah, yeah we are trying to entangle

0:48:38 Anne: Crystals. Yeah. Now, now I've got, like, not every photon that comes out of each each crystal is going to be exactly matched to the one I want to entangle to. And then, again, that's probabilistic, and that also kills your rate.

0:48:39 Thomas: Okay, yeah.

0:48:53 Thomas: Wait, do we need two crystals to entangle, I thought we just needed one, right?

0:48:57 Anne: Well, one crystal can produce an entangled pair. I want it to do something like teleport an entangled state, then I need another photon. Yeah.

0:49:01 Thomas: Holy shit, well, we'll set that aside because we're already actually out of time, I just looked at the water. Okay, damn. All right, let's see. This is so, this is great though. Cause I feel like I'm getting it to the tangible places where I can kind of fathom what's going on. All right. So you and I've done that. It's we, we, all those conditions aside, it takes a while for us to get those photons. So then we measure that we're getting them. Then we measure, okay, now I'm going to put mine through the polarity thing and we'd get enough measurements there to be like, Ooh, looks like, Hey, good news. I send you a greeting card that says we're entangled, baby. Baby.

0:49:13 Anne: That might be another discussion. Mm -hmm. Yep.

0:49:42 Thomas: Congrats on our entanglement.

0:49:42 Anne: Yep. At least I have sent you photons that are entangled with my photons. Yeah, yeah, so, we're, we'RE, we 'Re happy, yeah.

0:49:48 Thomas: Yeah. Right. Is that, I thought that's what I was saying. We're happy. Okay. Congrats. On our entANGLEment, everyone get our, go to our gift registry for our, for our photon entANGlement. So now we're confident we're doing that. So we're sending, we're getting, and you can do that essentially assuming you, you know, the lab conditions remain similar. You can do dat indefinitely, right? It's just a slow rate Of, okay, and now what do we want to do with these? Yeah.

0:49:57 Anne: Yes, yeah yeah, Now you get into the problem of your limitations here. So, yes, these photons are entangled. Um, pretend like we're, we're basically measuring them around the same time, and and we can pretend like we're light years away from each other, so I measure my photon and I get a horizontal, you measure your photon, you get a vertical, or, you know, depending on what kind of crystal you have, you're always going, every time I measure horizontal, you're also going to get a vertical.

0:50:33 Thomas: Okay. Okay. Yeah.

0:50:48 Anne: So yay. And when I make my measurement and you do it instantly after me, no matter how far we're separated in space, those measurements are still correlated with each other, or in this case, anti -correlated.

0:51:01 Thomas: So, Since we know this doesn't yield faster than light communication, essentially, let's maybe with the remaining time, and then we'll continue this discussion another time, let's dig really into why that is, so we understand, because hypothetically, and this happens in a lot of sci-fi, you'd think, all right, I'm gonna go out on my spaceship now. Now that we figured this experiment, now that our labs are working great, we're like, all right, here's what we're going to do. We're going get some entangled particles and we're gonna like save them. We're gonna put them in a freezer or something in the cooler, and we'll, we'll save them, and then I'm going to travel out like fucking forever, like a zillion years, and then we'll be able to instant communicate because like they're entangled. So then I'll be, I'll have my walkie talkie over here of entangled articles, and then I, I'll be able to be like, oh, I see that over on Earth, Anne's great, great, great, grand daughter is sending me something. So why doesn't that work?

0:51:55 Anne: It doesn't work is because you can't actually have information go over. And you've probably heard this, that you can't actually send information over faster than light. The reason why that is, is that you're dealing with a probabilistic mechanism where you can choose what you measure. So I can't choose to collapse the state into a particular value and say that's a zero, and then you measure yours and you see that that's a zero or I do a different one. And then you have that be a one.

0:52:06 Thomas: Yes. Right. Oh, we couldn't even just agree ahead of time somehow. We can't do that.

0:52:40 Anne: You could agree ahead of time, but then you haven't communicated faster than light because now you have an agreement ahead of time.

0:52:46 Thomas: Well, I'm saying you know, I's saying you to basically agree on, like, the it would be essentially be like the cipher is what I'm say. You can't agree, like, all right, while we're together, we'll agree that these following measurements or whatever mean zeros or ones, why all, right, but the problem is you can't reliably you on your end on earth trying to tell me something, can't just magically measure and get all the values of information that you would want to send, yeah so

0:53:00 Anne: On what the measurements mean. Certainly. Like, I could- we can agree that horizontal is a zero and a vertical is a one. But if they're in a quantum state, I can't choose what state to collapse it into, meaning I can'T control what message you're going to get. I just have to measure, and I get what I get, and you get what you get, and yes, it's correlated, but we don't have information.

0:53:33 Thomas: Okay, but we can't control it. Yeah, okay. So, yeah, so like you're trying, let's just send, you're trying to send a simple message, 001, or you're trying to do boobs on the calculator, 800, no, you are trying to, send me a message. And, and we, even though we agreed a time, ahead of time, okay? Horizontal means zero and vertical means one. And then you're on earth and you're like, okay here's what I'm going to do. I'm gonna send 8008, no I'm I'm going to send zero, zero, one, whatever. You can't do that because you don't know when you make the measurement, whether it's going to be vertical or horizontal. You just know that we're going to get opposites essentially.

0:53:42 Anne: Yeah. Yeah. Yeah. Yeah. Because if we want them to be entangled, they have to be in a quantum state. And if they're in a Quantum state, then that means that there's a probability of where it's going to collapse into.

0:54:25 Thomas: Yeah. So there's no set of like fucking crystals or mirrors we can set up that always collapses something into a certain state.

0:54:34 Anne: I could keep all the verticals, and you could have all the horizontals, but then we already knew what we had ahead of time.

0:54:38 Thomas: No, no, no. I mean like the entangled one, like there's nothing you can do to it. It. There's no way to do anything to it that gets you always, you you want to send a message, always horizontals for these and always verticals. There is no way to physically do that because of the universe. OK. There is also the other limitation that I think would make sense or would occur to me, which is how do I know which ones you've done and when?

0:54:54 Anne: Yeah, because that's, that's just the way that that's the other issue. You don't know when I've made a measurement. But However, I don't think that's as big of an issue because you could always prearrange. Like, let's say you, let, let's say we prepare a hundred photons ahead of time and we have memory and you go off in your spaceship and you're a hundred light years away and we have a, we could have a prearranged agreement to say, I'm going to measure photon one, then two, then three, then four.

0:55:08 Thomas: Yeah. Right.

0:55:30 Thomas: We've got 100 photon entangled photons in a in a beer cooler and we're like, all right, we'll agree at seven o 'clock local fucking star time that you're gonna, I'm gonna, and then I guess are we able to like individualize which ones we're doing? Because like we would have to go in a certain order, right, to be able to, right.

0:55:38 Anne: Yeah. Yeah. This is, this is also assuming a lot out of this thought experiment. Is it like, yeah, but

0:55:56 Thomas: Well, that's the thing, I want to know what the limited, the reasons we can't do this. We know we can't do this.

0:56:01 Anne: Let's pretend that we can do that. So let's pretend that we can sync our time.

0:56:05 Thomas: You saying that's at least physically possible? Like it's a, it's allowable. We just don't know if we'd ever be able to do it.

0:56:11 Anne: I mean, I can imagine, say you had a fiber that a photon could exist in indefinitely. You could just stick it in a loop and it goes around in that loop. And then you know which loop has the photon that you care about. This isn't practical, but okay, I Can. It doesn't break a law of physics.

0:56:23 Thomas: Sure. That sounds fun. At least maybe hypothetically possible. Yeah. And that's, and that's important. I do like, I, I think what we want to know as listeners is which things are maybe hypothetically possible and which things were just like, nope, universe says fucking no, no, no soup for you on the, and, and so that we'll say, we'll assume all that's at least possible for now. We'll say we can do, we can sync our clocks or whatever. Uh, and we can coordinate which ones we're measuring and when. And so we would theoretically the one limitation though, cause, cause all that would work out if we all had all that planned, we knew what the cipher was and you were like, "all right, I'm going to make this one be vertical, horizontal, vertical horizontal," whatever to send the message but you just can't do that part you're saying you can't you

0:56:28 Anne: Yeah, yeah. Yeah. Yeah, so let's say we have our entangled source. And we produce two memories that have a series of photons and we know which photons each. We know there's photon number one, number two, number three, and so forth. And you go off and let's pretend that we can sync our clocks so that we know when your clock hits 7 p.m. and my clock hits 6 p.m. that this is the time that we're going to do our measurement and we do our measurement, I decide which result I'm going to get I'm so let's pretend we have polarization entangled photons because that's usually what I work with, you measurement device is to put a polarizing beam splitter there and it just goes one way or the the other, because it's in a superposition of polarization.

0:57:10 Thomas: Oh mm -hmm dang uh -huh wow so yeah but I mean that's not necessarily obvious because I know when we talk about a lot of this stuff I feel like there is ways that you can put something through a lens a certain way or whatever that'll always yield you horizontals

0:58:12 Anne: Well let's, let's say we do, let's say we do that. Let's say that I know which we have, we have entangled photons and let's say I, I knew, I mean, there's ways to do this with the crystal. I can know which, which polarization polarization I have. So I know that polarization one is vertical and polarization two is horizontal and so forth, but then you already know that. And then you went on your ship.

0:58:12 Thomas: Right okay okay Okay. Yeah, then I essentially just took a handwritten note and traveled light years away and was like, fucking A, baby, we did it. We communicated. Yeah. You're right. Okay. So the only value.

0:58:39 Anne: Yeah. Yeah, still not transmitting information.

0:58:50 Thomas: But there is no way to do that after the fact. There's no way way to like have them be agnostic on polarization, be entangled, and then make them be a certain polarization.

0:59:04 Anne: Um, best I could come up with. And this still doesn't work, but the best that I can think of in my sci -fi addle brain is that, say, I used sort of entangled source to pump up some sort crystal. Now I'm going to switch on you and go with a nitrogen vacancy diamond, where I can have a certain spin live on one level of the crystal. And if it's spin zero, it decays to wavelength X, and if it's spin 1, it decays to wavelength Y. I could, say, entangle my spin so that that quantum state is preserved when somebody goes and takes their NV diamond somewhere else, and then if I decide to make a measurement, it collapses into one or the other. Unfortunately, this doesn't work either, but yeah, be the best I could come up with would be if you could have Alice make a measurement and Bob instantaneously know if a measurement has been made, but that still doesn't works, unfortunately.

0:59:13 Thomas: Yeah. Geez. Well,

1:00:23 Anne: So that, that's, that's the best I can come up for a sci-fi McGuffin. Well,

1:00:29 Thomas: If none of it works, why, why is any of them better than the other? They're both just zero. Good.

1:00:33 Anne: I mean, That, that that, for well, that's just because, because faster-than-light communication doesn't work.

1:00:34 Thomas: Right. I know, so it's like, you know, it just doesn't. But I find that fascinating because there's all these things that the non-locality thing does feel like it breaks some rule, you know, it feels like, okay, we all agreed on the rules of the universe and I wasn't told about this fucking thing. It still is cool that you could do that, like, you could at least hypothetically, while it's not transmitting information, you could at least, if you had the agreed upon time, and say we did that, so we've gotten a tingle particle, I drive my spaceship billion miles away, and, well, that's not even that far, actually, a gazillion gazillion million miles away, shouldn't use miles out there, it's a bad idea, don't know why, I stuck, we're still, by the way, we're in imperial, unfortunately, we're like using yardsticks out in space, it's just, yeah,

1:01:18 Anne: Oh, now, if talk to anybody from NIST, the National Institute of Standards and Technology, they love to tell you that we are, in fact, a metric country. It is, like, their favorite thing to tell You.

1:01:31 Thomas: All right, setting that aside, we have a pre -approved time or pre -agreed time, we not way out there, and I can at least know, like, all right, I'm gonna measure this one photon, oh, I got uh, horizontal, I at least no you have vertical, right, like, it's, it's not information per se, but it's like, it's, that's at least cool. Yeah. Like, like it is really remarkable. Like, all right, I know that you have that and I have this, even though we're a gajillion miles away and we didn't know it when we left, when I left and now, but we do know it now. That seems like something.

1:01:50 Anne: Warm and fuzzy.

1:02:07 Anne: Yeah, and that gets to one of the things of, like... Can you distribute random numbers this way? Can we use this as a mechanism for distributing random numbers? Um, isn't useless.

1:02:18 Thomas: Hmm. Interesting.

1:02:20 Anne: Um, there's a lot of uses for having good random numbers, the, there is people messing with your random numbers, oh, a hard thing to control for, but

1:02:29 Thomas: Don't know what any of that, so I don't know what that would do. Like, it does feel like there's gotta be some cryptography fucking way to do something with that, but I guess not. Because in the end, I guess what's cool is, even though it feels like that violates the rules, but it doesn't, they are literally entangled in that way, and you can do, no matter how far away you take them, assuming you know when to measure it, and I guess you got to know what, like, thing you measured, right? Like, you have to, you can't measure the wrong, like, spin, and I measured polar, and that kind of fucks us all up, right? Or could you could coordinate that.

1:02:59 Anne: But you definitely, definitely, you'd have to agree on that anyway. Yeah.

1:03:02 Thomas: Yeah. Yeah. So, assuming all that, they are really entangled and you don't know what they are. And even though they're light years and light years away, you don't really know what they are until this happens. And that's super cool. But thing I find so interesting about science in the universe is, even though that feels like it should be amazing and be able to do all this cool stuff, the universe is like, no, sorry, you still don't get to communicate faster than light because you just can't. I'm sorry. That's, we looked at the rules and no. No.

1:03:03 Anne: Um, I guess it's just causality is the thing that's, that's really the thing, it's, it's, I guess, is not particularly the speed of light per se, it's just you can't cause outcome happen before the cause, which is the limit on information. Oh,

1:03:41 Thomas: Why would that? Okay. Why would that happen before the cause?

1:03:44 Anne: I mean, that, that's like your, your limit, like, it's

1:03:47 Thomas: Well, let's say hypothetical. Let's get magical wand. Let's say you are able to get the polarities that you want from the ones you want. So you are like, all right, here's what I'm going to do. We agreed on the agreed upon time. I'm gonna make this one, one, two, three, four. I'm gonna make this 10, this one, one, this 10, this one, one, that, and let's say you had that ability, how would that break causality per se?

1:03:47 Anne: Um, know I did this as a test question when I took special relativity and the way that it was framed was, um, terms of the battle for Endor, if the, it was great.

1:04:20 Thomas: Uh, yeah. Oh, man, that's awesome, now, you gotta find this, oh,

1:04:30 Anne: So it was like, if The Millennium Falcon sends a missile when it gets this, um.

1:04:38 Thomas: I love this so much, okay, don't think they I I'm not sure do they have missiles in the Star Wars unit, whatever, a laser sir, all right,

1:04:38 Anne: Yeah, um, trying on the fly to think back to how this work, I'm well, we're pretending there's missiles now, yeah, or whatever, directed, I would have to go back and work out the way you do those time-space diagrams, but yeah, it worked out somehow, like, if you could, it's like if you got the message that there was a, a missile hit, it could happen before they sent the missile.

1:05:02 Thomas: Yeah, well, yeah, good point, because it does feel like whenever you're doing these relativity things, somehow it all equals fucking, if you can do anything faster than light, it does equal time travel somehow. Does that make sense? Um, right, sounds like you're, you're way past the time you said was okay, and I want to thank you so much for doing this, this was a lot of fun, it sounds like we have some fun follow-ups to do, I would love if you found that uh question, the Endor thing, because that would be super cool, I would love that so much, but yeah, I feel like, yeah, oh,

1:05:31 Anne: I'm just gonna have to work it out again and actually draw out the time -space diagram. Hi.

1:05:35 Thomas: I love it, oh, that's so cute, thank you so much, uh, and, and have a, have a, you know, a nice evening, uh, with your family that we can hear, um, we'll talk again very soon, take care.

1:05:46 Anne: See you. Yeah,