WEBVTT - What are virtual particles? 0:00:00.080 --> 0:00:02.520 Hey, this is Daniel and Jorge from Daniel and Jorge 0:00:02.560 --> 0:00:07.080 Explained the Universe. We interrupt this podcast for a special announcement. 0:00:07.280 --> 0:00:11.119 This Friday March We're having our first ever Daniel and 0:00:11.160 --> 0:00:14.560 Jorge Explained the Universe live stream event. So join us 0:00:14.560 --> 0:00:17.200 as we record an episode in real time and take 0:00:17.320 --> 0:00:20.520 questions from listeners like you. You can submit your questions 0:00:20.560 --> 0:00:22.560 live on air, or send them to us ahead of 0:00:22.560 --> 0:00:26.040 time at questions at Daniel and Jorghead dot com. To 0:00:26.160 --> 0:00:29.080 tune in, just go to YouTube dot com slash PhD 0:00:29.240 --> 0:00:33.320 Comics this Friday March at ten am Pacific. That's one 0:00:33.360 --> 0:00:37.159 pm Eastern, six pm Europe. That's two am in Tokyo 0:00:37.320 --> 0:00:40.760 and four am in Australia. What time it's out of Mars, Daniel, 0:00:40.920 --> 0:00:42.880 You know in case aliens want to tune in? Do 0:00:42.920 --> 0:00:47.239 you think aliens want to ask us questions? Um? May not, 0:00:47.320 --> 0:00:50.519 you may they might have engineering questions. You know, well 0:00:50.560 --> 0:00:53.160 I got questions for them. So tune in this Friday, 0:00:53.200 --> 0:00:56.440 March twenty seven at ten am Pacific at YouTube dot 0:00:56.480 --> 0:01:10.479 com slash PhD Comics and bring your question about the universe. Hey, Daniel, 0:01:10.480 --> 0:01:13.560 are you a fan of virtual reality? I'm still trying 0:01:13.600 --> 0:01:16.000 to get my head around this reality? What do I 0:01:16.040 --> 0:01:18.680 need another one for? You know you can? You can 0:01:18.760 --> 0:01:20.479 use it to walk on the surface of the Moon 0:01:20.800 --> 0:01:24.440 without ever leaving your couch. That does actually sound pretty good. 0:01:24.760 --> 0:01:28.559 But isn't it expensive? Here? It's virtually free. I think 0:01:28.640 --> 0:01:31.840 that means it's expensive. Actually, I think it is. Can 0:01:31.880 --> 0:01:33.840 I can I borrow some cash from you? Yeah? Sure, 0:01:33.880 --> 0:01:52.440 I'll send you some virtual money. I am or had 0:01:52.440 --> 0:01:55.240 any cartoon is and the creator of PhD comments, Hi, 0:01:55.400 --> 0:01:58.280 I'm Daniel. I'm a particle physicist, and I'm the co 0:01:58.440 --> 0:02:01.760 author of our book, We Have No Idea, A Guide 0:02:01.760 --> 0:02:06.320 to the Unknown Universe. It's available in paperback, hardcover and 0:02:06.360 --> 0:02:10.079 also virtual reality. You can put on goggles and experience 0:02:10.120 --> 0:02:15.520 being inside our minds. Oh man, that sounds terrifying. Is 0:02:15.520 --> 0:02:18.320 that a horror show? But welcome to our podcast Daniel 0:02:18.320 --> 0:02:21.119 and Jorge Explain the Universe, a production of I Heart 0:02:21.160 --> 0:02:24.240 Radio in which we take mental tours all over the 0:02:24.360 --> 0:02:27.520 universe and talk about the biggest things, the smallest things, 0:02:27.560 --> 0:02:30.800 the fastest things, the craziest things in the universe and 0:02:30.880 --> 0:02:32.600 explain all of them to you in a way we 0:02:32.680 --> 0:02:36.400 hope you find educational and entertaining. Yeah, that's hard. We 0:02:36.400 --> 0:02:38.440 talked about all the real things out there in the 0:02:38.520 --> 0:02:41.280 universe and the cosmos and the furthest reaches of the 0:02:41.320 --> 0:02:44.839 galaxies and galaxy clusters, but we also like to talk 0:02:44.880 --> 0:02:49.160 about things dad don't yet exist or may not even exists. 0:02:49.360 --> 0:02:51.800 That's right. We want to take you inside the minds 0:02:51.840 --> 0:02:54.960 of scientists and tell you how they think about the universe, 0:02:55.320 --> 0:02:57.600 what models are going on in their head, and can 0:02:57.639 --> 0:02:59.919 we distill those in a way that makes sense to you, 0:03:00.440 --> 0:03:03.360 because we want you to understand sort of the forefront 0:03:03.360 --> 0:03:06.799 of human thinking about how the universe works. Yeah, because 0:03:06.960 --> 0:03:09.000 there are the things that are around us that we 0:03:09.000 --> 0:03:13.200 can see and touch and feel and hold in our hands, 0:03:13.480 --> 0:03:16.360 but there's sort of another universe out there that we 0:03:16.440 --> 0:03:20.519 can't see, and that is maybe not quite as real 0:03:20.560 --> 0:03:23.200 as you might imagine. Yeah. Well, we're always sort of 0:03:23.240 --> 0:03:26.359 building a universe in our minds to map what's going 0:03:26.400 --> 0:03:30.040 on outside. Like we can do experiments, we can make measurements, 0:03:30.080 --> 0:03:32.440 We can see things, and then we try to understand them, 0:03:32.720 --> 0:03:35.360 and that understanding requires building a model in our head 0:03:35.360 --> 0:03:38.200 of what we think is happening. And some of those 0:03:38.240 --> 0:03:40.880 things we can experience some of those things we wonder 0:03:40.960 --> 0:03:44.080 are they real or are they just our imagination? Yeah, 0:03:44.120 --> 0:03:46.640 So Daniel and I we wrote a book Daniel called 0:03:46.960 --> 0:03:48.680 you know, We Have No Idea. I don't know if 0:03:48.680 --> 0:03:50.440 you know we wrote a book by the way, I 0:03:50.440 --> 0:03:53.200 had no Idea? Is that right? Yeah? Yeah, it's called 0:03:53.240 --> 0:03:55.320 We Have No Idea? And uh. And then we talk 0:03:55.360 --> 0:03:57.440 about all the things we don't know about the universe, 0:03:57.520 --> 0:04:00.400 all the unanswered questions out there. Um of those of 0:04:00.440 --> 0:04:02.640 you listening, please check it out if you are interested. 0:04:03.120 --> 0:04:05.280 But I was sort of surprised to get today's topic 0:04:05.440 --> 0:04:07.480 in an email for me this morning, because I don't 0:04:07.520 --> 0:04:09.880 think we covered this topic in that book. No, this 0:04:09.960 --> 0:04:12.280 is a really tricky topic, and it really has to 0:04:12.280 --> 0:04:15.760 do with how physicists think about particles, what they mean, 0:04:16.279 --> 0:04:18.719 and are they real? How do they talk to each other, 0:04:18.880 --> 0:04:23.040 what happens when one electron pushes against another electron, and 0:04:23.080 --> 0:04:25.240 how does that end? What happens inside the mind of 0:04:25.240 --> 0:04:28.760 a physicist when she thinks about that. So this topic 0:04:28.800 --> 0:04:31.280 that we're going to talk about today, was it just 0:04:31.320 --> 0:04:33.600 too maybe extreme for our book? What did you think? What? 0:04:33.920 --> 0:04:36.839 Why didn't we talk about it in our fun and 0:04:37.040 --> 0:04:40.320 interesting book? Now? Available for purchase what we totally could have. 0:04:40.720 --> 0:04:42.200 And you know, in the book, we have to make 0:04:42.240 --> 0:04:45.400 some pretty hard choices about what topics to cover. We 0:04:45.480 --> 0:04:47.720 talked about what is space and what is time? And 0:04:47.760 --> 0:04:50.400 what is matter? And how will the universe end? And 0:04:50.480 --> 0:04:52.600 we could have gone on forever and talked about all 0:04:52.640 --> 0:04:55.520 the things we don't understand about the universe. It's a 0:04:55.520 --> 0:04:58.160 pretty long list, but we had to make some choices. 0:04:59.040 --> 0:05:01.480 I see, the book wasn't called we have lots of 0:05:01.480 --> 0:05:06.320 no ideas. We have absolutely zero ideas about a lot 0:05:06.360 --> 0:05:10.320 of things. But anyway, so today's talpic. It's pretty interesting 0:05:10.920 --> 0:05:13.800 because I think everyone has heard of particles. I mean, 0:05:13.960 --> 0:05:16.080 we all know that we are made out of molecules 0:05:16.120 --> 0:05:18.160 and atoms, and atoms are made out of particles, and 0:05:18.400 --> 0:05:22.040 they form the basis of for matter in all of 0:05:22.120 --> 0:05:24.640 the universe. But I think maybe not not a lot 0:05:24.680 --> 0:05:28.039 of people have heard about this particular type of particle. Yeah, 0:05:28.200 --> 0:05:30.680 this is a concept that people talk about when they 0:05:30.720 --> 0:05:33.800 think about you know, empty space and particles popping in 0:05:33.920 --> 0:05:37.120 and out of the vacuum. And it's a topic that's 0:05:37.160 --> 0:05:40.200 really important for thinking about forces and how things push 0:05:40.279 --> 0:05:43.080 and pull against each other and how that actually works 0:05:43.160 --> 0:05:46.600 at the microscopic level. So it's a really important concept 0:05:46.760 --> 0:05:48.960 in particle physics, but it's sort of slipper and you 0:05:49.000 --> 0:05:51.720 get your head around. But recently some listeners wrote in 0:05:51.800 --> 0:05:53.960 and asked us to explain this to be on the podcast, 0:05:54.000 --> 0:06:03.080 we'll be asking the question what is a virtual particle? 0:06:03.400 --> 0:06:06.400 Is it a particle wearing virtual reality goggles? Is it 0:06:06.480 --> 0:06:10.239 one particle imagining another particle? Is it a virtuous particle 0:06:10.720 --> 0:06:14.680 who has a Stanza for its principles? These particles all 0:06:14.800 --> 0:06:18.159 follow rules. Actually, that's a really good point because there's 0:06:18.160 --> 0:06:21.640 a lot of sort of pop science misinformation about virtual particles. 0:06:21.960 --> 0:06:24.760 People say, oh, virtual particles don't follow the laws of physics, 0:06:24.839 --> 0:06:27.560 But they do. They follow the laws of physics absolutely, 0:06:27.839 --> 0:06:29.839 just like all the other particles and as far as 0:06:29.920 --> 0:06:33.560 we know, everything in our real universe. Interesting. I like 0:06:33.640 --> 0:06:38.640 how you associate virtue with following the rules. Some deep 0:06:38.680 --> 0:06:43.040 psychological things going on there. Daniel today on the podcast 0:06:43.120 --> 0:06:48.560 Therapy of Daniel, How are you feeling steep virtually good? 0:06:49.720 --> 0:06:54.200 Particularly virtual particular? Well, so it's an interesting topic. I 0:06:54.279 --> 0:06:56.719 have to say, I've never heard of these virtual particles. 0:06:56.920 --> 0:06:59.840 I guess because they're virtual. Is that part of what 0:07:00.000 --> 0:07:02.599 we're gonna talk about today. Yeah, a little bit. They're 0:07:02.600 --> 0:07:06.159 not real, Are they not real? Well, they are real, 0:07:06.320 --> 0:07:09.000 they're just not really particles. There are a thing that's 0:07:09.040 --> 0:07:11.880 out there in the universe. They're responsible for important physical 0:07:11.960 --> 0:07:14.200 effects that we can see, but we can never see 0:07:14.320 --> 0:07:17.000 them directly. So one way to think about them is 0:07:17.040 --> 0:07:20.120 that they're sort of a calculational tool in our minds, 0:07:20.200 --> 0:07:22.400 a way that we think about what's happening out there 0:07:22.440 --> 0:07:24.720 in the universe, but not something that we can have 0:07:24.960 --> 0:07:28.720 ever observed directly, sort of like we think about quantum 0:07:28.760 --> 0:07:32.160 mechanical wave functions. We never observe the wave function itself. 0:07:32.240 --> 0:07:36.000 We only observe its consequences, it's influence on things. But 0:07:36.120 --> 0:07:39.640 it's important for us to predict those those experiments, to 0:07:39.720 --> 0:07:42.600 predict those consequences, that we can use that in our calculations. 0:07:42.720 --> 0:07:45.119 All right, well let's get let's get into it here today. 0:07:45.200 --> 0:07:48.080 But first we were wondering, as usual, how many people 0:07:48.120 --> 0:07:50.960 out there and you what a virtual particle was. So 0:07:51.160 --> 0:07:53.440 I walked around campus that you see Irvine, and I 0:07:53.600 --> 0:07:56.640 asked people this kind of crazy as a terror question. 0:07:57.000 --> 0:07:58.840 So before you hear these answers, think about it for 0:07:58.880 --> 0:08:00.800 a second. If someone asked you on this treet, what 0:08:01.000 --> 0:08:04.720 is a virtual particle? What would you answer? Here's what 0:08:04.840 --> 0:08:08.679 people had to say, not in the slowest an imaginary particle, 0:08:09.160 --> 0:08:13.160 Houston light theories or something like that. Virtual state is 0:08:13.720 --> 0:08:18.040 a state, kind of a transitory state where if you're 0:08:18.040 --> 0:08:21.040 going to do like a two photon excitation, it's that 0:08:21.240 --> 0:08:25.400 state in the middle that is a virtual state where 0:08:25.480 --> 0:08:28.960 it's not really you can't describe I can't describe it 0:08:29.080 --> 0:08:31.960 very well. I'm not into physics, but that's that's the 0:08:32.040 --> 0:08:34.520 best I can do on that one. It's a particle 0:08:35.320 --> 0:08:40.360 of matter. I don't know, something that's made up based 0:08:40.400 --> 0:08:44.600 on technology. Maybe all right? Virtually no one said yes, 0:08:46.559 --> 0:08:48.480 there was some creative answer, though. I really like the 0:08:48.520 --> 0:08:51.640 person that said something that's made up based on technology. 0:08:52.080 --> 0:08:54.520 That sounds pretty good. Like I was, I could use 0:08:54.640 --> 0:08:57.720 technology to create new particles. That's sort of my job, 0:08:58.360 --> 0:09:00.760 isn't that what you do? Did you create new particles? 0:09:01.120 --> 0:09:03.360 That's what I'm supposed to be doing, and I'm using 0:09:03.400 --> 0:09:05.520 a lot of technology and spending a lot of government money, 0:09:05.559 --> 0:09:09.520 but instead you're here recording a podcast. Don't tell anybody 0:09:10.760 --> 0:09:14.400 that's right, nobody knows about this, Daniel, don't worry. But 0:09:14.520 --> 0:09:17.680 you know, an attempt only a few thousand people listen. 0:09:17.880 --> 0:09:20.760 In my twenty years of searching for new particles, I've 0:09:20.880 --> 0:09:24.000 never really found one. So I'm using technology to try 0:09:24.040 --> 0:09:26.440 to find new particles. I just haven't been successful yet. 0:09:27.280 --> 0:09:29.640 You're like, forget particles. I'm just gonna have a party. 0:09:31.280 --> 0:09:35.000 It's a virtually easier But you know, this wasn't too surprising. 0:09:35.120 --> 0:09:37.599 It's a sort of esoteric topic, and I think a 0:09:37.679 --> 0:09:41.080 lot of people know why virtual particles are important without 0:09:41.120 --> 0:09:43.959 knowing the concept itself. So I think you'll find that 0:09:44.040 --> 0:09:46.960 the things we talk about the role virtual particles play 0:09:47.200 --> 0:09:49.800 will be familiar to a lot more people than actually 0:09:49.880 --> 0:09:53.160 know what virtual particles are and can explain. It's not 0:09:53.240 --> 0:09:56.480 a crazy concept. It's just maybe kind of a naming 0:09:56.640 --> 0:09:59.080 convention or sort of like how this is to see 0:09:59.160 --> 0:10:02.240 some of these particles? Yeah, precisely. All right, Well let's 0:10:02.240 --> 0:10:05.000 gett into it, Daniel. What is a virtual particle and 0:10:05.120 --> 0:10:08.800 why is it called virtual? And is it not real? Well? 0:10:08.840 --> 0:10:11.120 I think first let's get a clear picture for like 0:10:11.240 --> 0:10:13.000 what is what do we mean by a particle in 0:10:13.120 --> 0:10:15.920 a real particle? Because as you talked about earlier, like 0:10:15.960 --> 0:10:18.000 we're made of stuff. I made of stuff, You're made 0:10:18.040 --> 0:10:20.520 of stuff. We think when we are real, like I 0:10:20.600 --> 0:10:23.600 imagine I'm real, and we think that we're made of particles, 0:10:23.640 --> 0:10:26.600 and those particles have an existence. They're like stick around, 0:10:26.720 --> 0:10:29.319 they have persistence, that can move through space, all this 0:10:29.440 --> 0:10:32.880 kind of stuff, and we feel substantial, and so you 0:10:33.000 --> 0:10:35.600 and I we are made of real particles. But those particles, 0:10:35.800 --> 0:10:38.520 they're not like a little ball of stuff, and they're 0:10:38.559 --> 0:10:41.120 not like a tiny dot, right, It's not like we're 0:10:41.120 --> 0:10:43.520 built out of little tinker toys. As we've talked about 0:10:43.520 --> 0:10:46.280 in the podcast several times, each of these particles should 0:10:46.280 --> 0:10:49.240 be seen as like a ripple in a quantum field. 0:10:49.800 --> 0:10:52.319 It's like you have this field that feels space and 0:10:52.440 --> 0:10:55.120 at some points that has energy and it's vibrating, and 0:10:55.240 --> 0:10:57.559 that's what each of these particles are. It's like a 0:10:57.600 --> 0:11:01.120 little perturbation in in reality. Kind of yes, it's a 0:11:01.160 --> 0:11:03.480 little perturbation in reality. And the key thing to know 0:11:03.800 --> 0:11:07.559 is that real particles are special perturbations. There's not like 0:11:08.120 --> 0:11:10.599 any perturbation in the quantum field is a part is 0:11:10.640 --> 0:11:14.600 a real particle there if that perturbation follows certain rules 0:11:14.640 --> 0:11:18.400 and has certain behaviors and has and obeys certain equations. 0:11:18.800 --> 0:11:22.880 Then it's a real particle. You're saying, there are perturbations 0:11:23.040 --> 0:11:26.160 that are not particles that or that don't form particles. 0:11:26.520 --> 0:11:29.760 There aren't quantum fields. Yes, And that's uh, you just 0:11:29.840 --> 0:11:32.600 gave away the ghosts. Because some perturbations are real particles 0:11:32.640 --> 0:11:37.720 and some perturbations are virtual particles. So some small fraction 0:11:37.760 --> 0:11:40.560 of the perturbations and quantum fields are what make up 0:11:40.640 --> 0:11:42.679 real particles. That are you and me. I guess my 0:11:42.760 --> 0:11:46.000 question is what makes a real particle real? What makes 0:11:46.040 --> 0:11:50.120 that proturbation real? Well, it can do various things, Like 0:11:50.720 --> 0:11:53.920 it can travel forever. Right, you shoot a real particle 0:11:53.960 --> 0:11:56.319 through space, it will just keep going until it bounces 0:11:56.360 --> 0:11:59.760 into something. It has this sort of self sustaining nature 0:11:59.800 --> 0:12:02.160 to it. It doesn't just like spread out into nothing 0:12:02.400 --> 0:12:06.440 or cancel itself out and and and it's propagating right 0:12:06.520 --> 0:12:08.719 through the field. It's not like it's moving. It's like 0:12:08.800 --> 0:12:12.559 it's I'm a perturbation here, and then I'm proturbing the 0:12:12.640 --> 0:12:15.319 space next to me, and that's what we call moving. 0:12:15.600 --> 0:12:17.439 That's right, And you need to keep two pictures in 0:12:17.480 --> 0:12:19.720 your head. At once. One is sort of the quantum 0:12:19.800 --> 0:12:22.439 field theory view, like think about the whole universe is 0:12:22.559 --> 0:12:25.320 just space filled with quantum fields, and as you say, 0:12:26.120 --> 0:12:28.800 a particle moving through them. Is the wiggle in the 0:12:28.880 --> 0:12:30.600 field is here, and then the wiggle in the field 0:12:30.679 --> 0:12:33.120 is there, So that wiggle is the thing that's propagating. 0:12:33.200 --> 0:12:35.520 Is the energy moving At the same time, you like 0:12:35.679 --> 0:12:38.000 to associate that will with a particle. You have maybe 0:12:38.080 --> 0:12:40.440 this image in your head of like a little ball 0:12:40.640 --> 0:12:43.080 that's moving from here to there. And in fact, if 0:12:43.080 --> 0:12:45.920 you shoot an electron out of an electron gun, that's 0:12:45.960 --> 0:12:49.679 sort of what you imagine. The most mathematically accurate way 0:12:49.760 --> 0:12:52.079 to think about it is in terms of a little 0:12:52.200 --> 0:12:55.040 ripple in the field that's moving through the field. But 0:12:55.400 --> 0:12:58.200 you like to associate that with a real electron because 0:12:58.200 --> 0:13:01.440 it has properties like mass and it can fly forever 0:13:02.000 --> 0:13:05.480 um if it doesn't touch anything and that and that's 0:13:05.480 --> 0:13:08.679 a real particle because it satisfies various rules like it 0:13:08.840 --> 0:13:12.199 has a specific mass and it's kinetic energy. Makes sense, 0:13:12.640 --> 0:13:15.360 you know, you can interpret that ripple as a particle. 0:13:15.559 --> 0:13:17.160 Did you have to do with like the shape of 0:13:17.240 --> 0:13:21.360 it or yes, it has What makes it special is 0:13:21.400 --> 0:13:23.880 it just like a set of conditions that made it 0:13:24.120 --> 0:13:28.600 is special, or there's something about the combination of things 0:13:28.679 --> 0:13:31.720 that went into it that caused ripple to be special. 0:13:31.840 --> 0:13:34.199 In a like the shape of it. It has a 0:13:34.280 --> 0:13:35.920 lot to do with how it was made. And you 0:13:36.000 --> 0:13:38.960 can imagine, for example, a guitar string. Take your guitar string. 0:13:39.200 --> 0:13:41.800 If you plug it carefully, it has various modes that 0:13:41.920 --> 0:13:44.400 it likes to wiggle at, right, and those are the 0:13:44.480 --> 0:13:46.800 various notes of the guitar string. And you can, you know, 0:13:46.920 --> 0:13:49.319 make the string shorter or longer to change those modes. 0:13:49.640 --> 0:13:51.920 But just for like an open string, you play it, 0:13:52.200 --> 0:13:54.120 it makes it. It likes to play it a certain 0:13:54.320 --> 0:13:57.320 a certain frequency. But you could also do other things 0:13:57.400 --> 0:14:00.240 on that string that aren't like a nice awcole shan. 0:14:00.679 --> 0:14:02.360 You know, if your toddler comes in the room and 0:14:02.480 --> 0:14:05.199 hits your guitar with with something crazy, it doesn't make 0:14:05.360 --> 0:14:07.959 a nice sound. So you can imagine the difference between 0:14:08.000 --> 0:14:11.160 like a careful, clean plucking of the string that sends 0:14:11.280 --> 0:14:15.199 one well behaved wave propagating down the string, and a 0:14:15.280 --> 0:14:19.040 sort of chaotic tumble of ripples that don't that can't 0:14:19.040 --> 0:14:22.360 be interpreted the same way and because you're saying quantum 0:14:22.440 --> 0:14:26.320 fields can be disturbed in any number of ways, but 0:14:26.480 --> 0:14:28.760 like if you disturb it just right, it'll create this 0:14:28.880 --> 0:14:34.360 kind of like perfect self sustaining um, you know, bumping it, yes, 0:14:34.560 --> 0:14:37.320 and precisely. And the thing that it has it has 0:14:37.360 --> 0:14:41.040 a definite mass. So an electron always has an electron's mass, 0:14:41.080 --> 0:14:44.040 and it moves through the universe always having the same mass. 0:14:44.600 --> 0:14:47.800 And so a real particle something that has a definite mass, 0:14:47.880 --> 0:14:50.200 that has that stuff to it. That's the thing that 0:14:50.360 --> 0:14:53.400 makes it real that it has a specific mass, and 0:14:53.520 --> 0:14:56.000 you can interpret things about it that we're familiar with. Right, 0:14:56.360 --> 0:14:59.480 You like to think, well, things have energy, like kinetic energy. 0:14:59.720 --> 0:15:03.360 Are particle has a positive kinetic energy? That makes sense. 0:15:03.840 --> 0:15:06.240 Later and we talk about virtual particles, you'll see that 0:15:06.400 --> 0:15:08.920 they don't obey these same rules. They can't be interpreted 0:15:08.960 --> 0:15:11.520 in the same way. There's still ribbles in the quantum field, 0:15:11.560 --> 0:15:14.600 but they're not nice, clean ripples that follow these rules. 0:15:15.320 --> 0:15:20.520 They're not that virtuous judgment. I'm a particle physicists. All 0:15:20.560 --> 0:15:23.960 particles are welcome in my mind, except they want that 0:15:24.000 --> 0:15:27.080 break rules. Apparently, well, they don't break. They don't break 0:15:27.080 --> 0:15:29.760 the rules. It's a category, right, These are these that 0:15:30.120 --> 0:15:33.640 you know satisfy some restrictions we call those. Really they 0:15:33.720 --> 0:15:35.760 do certain things. It's just a label in our minds. 0:15:36.000 --> 0:15:38.640 It's a distinction in our head Some of them have 0:15:38.720 --> 0:15:41.640 a mass that sticks around forever and and and you know, 0:15:42.160 --> 0:15:44.960 and follow these um these I guess they are rules. Yes, 0:15:45.160 --> 0:15:46.880 I'm trying to I'm always saying that, But you're right, 0:15:47.640 --> 0:15:52.440 m I do like rules for it. We'd be nothing 0:15:52.520 --> 0:15:56.040 without rules. All right, Well, let's get into then, what 0:15:56.240 --> 0:16:00.360 are virtual particles and whether or not they're real or 0:16:00.600 --> 0:16:04.680 whether you can only see them on a VR headset. 0:16:04.880 --> 0:16:20.080 But first let's take a quick break. All right, Daniel, 0:16:20.120 --> 0:16:22.600 we're talking about virtual particles, and you're saying, a real 0:16:22.680 --> 0:16:26.280 particle is like a perturbation in a quantum field which 0:16:26.320 --> 0:16:30.680 surrounds us all around. And but it's like a perfect perturbation. 0:16:30.720 --> 0:16:32.840 That's what a real particle is. It's like something that 0:16:33.040 --> 0:16:36.400 somehow the field really likes and doesn't just kind of 0:16:36.480 --> 0:16:40.560 like destroys or dissipates. Yeah, there are lots of different 0:16:40.600 --> 0:16:44.920 kinds of perturbations, and some of them satisfy additional constraints. 0:16:45.280 --> 0:16:48.240 Some of them satisfy a subset of them also satisfy 0:16:48.320 --> 0:16:51.640 some equations, some wave equations that tell us about how 0:16:51.680 --> 0:16:54.240 they move, and those real part of universe likes them. 0:16:54.440 --> 0:16:56.960 They're like, hey, I like this sound, I like this note. 0:16:57.400 --> 0:16:59.560 I'm just gonna let it keep on going. You're speaking 0:16:59.600 --> 0:17:01.920 for the U niverse, now, do that's a bit presumptuous. 0:17:02.120 --> 0:17:04.040 Maybe the universe likes the other kind of particles. It 0:17:04.080 --> 0:17:07.400 thinks the real particles are like boring rule followers. Oh, 0:17:07.560 --> 0:17:11.720 I see, well, somehow it allows the real particles to 0:17:12.160 --> 0:17:15.399 to be a special right, yes, sort of like them. Well, 0:17:15.440 --> 0:17:19.119 the real particles, real particles can do something that virtual 0:17:19.200 --> 0:17:21.640 particles can't. But virtual particles can do lots of things 0:17:21.720 --> 0:17:25.320 real particles can't. So what can real particles do that 0:17:25.480 --> 0:17:29.119 virtuals can't. Well, real particles can propagate across the universe. 0:17:29.200 --> 0:17:31.320 They have a fixed mass, and that carries them sort 0:17:31.359 --> 0:17:35.080 of through space. You're saying forever nothing. They don't degrade. 0:17:35.400 --> 0:17:37.359 They don't degrade. Like you look up at the sky 0:17:37.600 --> 0:17:40.560 and a photon hit your I from a far away star. 0:17:40.920 --> 0:17:43.920 That's a real photon. It's propagated through space and it 0:17:43.960 --> 0:17:46.640 could have got another billion light years if your eye 0:17:46.680 --> 0:17:49.560 hadn't blocked it. So, yeah, these things can travel forever. 0:17:50.280 --> 0:17:52.680 But there are real particles also that don't last, like 0:17:52.800 --> 0:17:54.399 don't we Are you telling me that some of the 0:17:54.480 --> 0:17:58.520 higher energy particles, like the you know, some of these 0:17:58.840 --> 0:18:02.919 heavy cords, they at some point they break apart. Yes, um, 0:18:03.240 --> 0:18:06.560 higher mass particles are unstable, but they're still real. They're 0:18:06.600 --> 0:18:10.200 real particles, but they can decay into lower mass particles. 0:18:10.600 --> 0:18:13.119 So not every particle has an infinite lifetime like an 0:18:13.160 --> 0:18:16.200 electron or a photon, but they are still real. You 0:18:16.240 --> 0:18:17.679 can interact with them, you can see them, they can 0:18:17.760 --> 0:18:20.840 propagate through space. All right. Well, then let's get into 0:18:20.920 --> 0:18:23.760 what a virtual particle is. So I guess it means 0:18:23.800 --> 0:18:26.480 it's not a real particle. Yeah, it's not a not 0:18:26.600 --> 0:18:29.440 a clean ripple. It's like everything else, you know, it's 0:18:29.760 --> 0:18:33.760 any other kind of disturbance in the quantum field, right, 0:18:34.280 --> 0:18:36.840 And it's like a transfer of energy from one place 0:18:36.920 --> 0:18:38.520 to another in the field. I mean, that's what the 0:18:38.560 --> 0:18:42.160 disturbance is. But it's not something you can coalesce together 0:18:42.200 --> 0:18:43.800 and say, oh, this is a nice little packet of 0:18:43.920 --> 0:18:46.439 energy that moves in a tight way through the field 0:18:46.480 --> 0:18:49.119 and we'll stay that way. It like diffuses out, it 0:18:49.240 --> 0:18:52.960 spreads out, it fades away pretty quickly. Wait, so it's 0:18:53.040 --> 0:18:58.560 possible for feels to be disturbed, not in particles. It's 0:18:58.600 --> 0:19:00.760 possible for people feel to be disturbed in a way 0:19:00.840 --> 0:19:03.879 that makes a real particle. It's also possible for fields 0:19:03.920 --> 0:19:05.760 to be disturbed in a way that doesn't make a 0:19:05.840 --> 0:19:08.320 real particle. What do we call that? We call that 0:19:08.359 --> 0:19:11.040 a virtual particle. Do they break sort of the rule 0:19:11.080 --> 0:19:13.760 of quantum mechanics, like the minimum amount of energy and 0:19:13.880 --> 0:19:16.040 things like that, Like, is it possible to have a 0:19:16.119 --> 0:19:18.600 ripple that's smaller than an electron? For example, you have 0:19:18.760 --> 0:19:21.160 ripples in the electron field that don't have the mass 0:19:21.240 --> 0:19:24.480 of an electron. Yes, but they're not breaking any of 0:19:24.560 --> 0:19:27.320 the rules. This is a common misunderstanding. They follow the 0:19:27.400 --> 0:19:30.480 rules of physics, but you know those rules have fuzziness 0:19:30.560 --> 0:19:32.639 in them. So, for example, if you do something in 0:19:32.680 --> 0:19:35.359 a very short amount of time, then the energy these 0:19:35.400 --> 0:19:39.160 particles is very uncertain because there's an uncertainty relationship between 0:19:39.240 --> 0:19:42.240 time and energy, like there is between momentum and space, 0:19:42.920 --> 0:19:44.800 and so there are a lot of things they can 0:19:44.840 --> 0:19:47.120 do that seem like they're breaking the rules, but isn't 0:19:47.160 --> 0:19:51.440 actually Well, wait, so you can't have a ripple in 0:19:53.000 --> 0:19:56.200 that's smaller than an electron. Then you can have a 0:19:56.400 --> 0:19:59.399 ripple in the electron field that doesn't correspond to one 0:19:59.480 --> 0:20:02.800 wheel of drown it's smaller, it's a smaller ripple than 0:20:02.880 --> 0:20:05.240 one real electron. You might be thinking to hold on. 0:20:05.359 --> 0:20:07.640 The field is supposed to be quantized, and that's true, 0:20:08.080 --> 0:20:10.880 but that applies to real particles and in the case 0:20:10.960 --> 0:20:14.919 of virtual part and you just broke over my head, Daniel. 0:20:16.000 --> 0:20:18.120 All this time I thought it was like a fundamental 0:20:19.280 --> 0:20:22.240 rule of the universe that that quantum fields can't ripple 0:20:22.480 --> 0:20:26.840 with anything smaller than than than the quantum particles. But 0:20:26.880 --> 0:20:29.800 you're saying they can't. They're just not real. Those are different, 0:20:30.000 --> 0:20:33.960 not sustainable, they're not sustainable ripples. Yeah, and you know 0:20:34.080 --> 0:20:37.000 the thing you're talking about are self sustaining. Real particles 0:20:37.200 --> 0:20:39.000 create one, you can create two, you can create three. 0:20:39.040 --> 0:20:42.200 You can't contain two and a half. Right, there's there's 0:20:42.240 --> 0:20:45.119 no self sustaining mode. They can do that. But if 0:20:45.119 --> 0:20:47.680 you're gonna have chaotic fluctuations of the field, then you 0:20:47.680 --> 0:20:50.520 can have all sorts of crazy stuff. And so yeah, 0:20:50.560 --> 0:20:53.560 that releases you from a lot of those requirements. Okay, 0:20:53.600 --> 0:20:55.840 and these ripples you're saying, they don't propagate, or they 0:20:55.880 --> 0:20:58.639 do propagate. They propagate, but they don't propagate as far. 0:20:58.680 --> 0:21:00.439 They don't hold themselves to get other and so they 0:21:00.480 --> 0:21:02.720 don't sustain themselves. They sort of just like spread out 0:21:02.760 --> 0:21:05.760 and diffuse and eventually they sort of cancel themselves out. 0:21:06.840 --> 0:21:10.520 When you mean what happens to them, They they like separate, 0:21:10.600 --> 0:21:14.480 they become you know, inquirent or well, they're very short lived, 0:21:14.560 --> 0:21:17.360 they're transient. And so for example, a virtual particle might 0:21:17.440 --> 0:21:20.440 be like a little blob of energy that one electron 0:21:20.560 --> 0:21:23.400 sends to another electron to push it away, Like two 0:21:23.440 --> 0:21:27.160 electrons they push each other apart. Right, how does that happen, Well, 0:21:27.200 --> 0:21:30.760 it happens through ripples in the electromagnetic field. And you 0:21:30.840 --> 0:21:33.800 can that's not really a photon, Like it's not a 0:21:33.920 --> 0:21:36.960 flash of light that goes between the electrons to push 0:21:37.040 --> 0:21:39.399