WEBVTT - Could some particles have tiny electric charges? 0:00:08.440 --> 0:00:10.720 Hey, Daniel, you have an electric car, right, Yeah, I 0:00:10.840 --> 0:00:14.080 drive a Nissan Leaf these days, and last time I 0:00:14.160 --> 0:00:17.280 had a Chevy bolt, so you bolted from the bolt 0:00:17.760 --> 0:00:22.200 and to turn over a new leaf, I left it behind. Now, 0:00:22.200 --> 0:00:24.280 how much does it cost to charge up with one 0:00:24.280 --> 0:00:27.200 of those electric cars? Well, that's kind of a charged question, 0:00:27.360 --> 0:00:30.560 but usually less than ten dollars. Actually, oh wow, you 0:00:30.600 --> 0:00:32.879 only charge you ten bucks to charge your car? You 0:00:32.920 --> 0:00:35.000 go to one of those charging stations. No, I usually 0:00:35.080 --> 0:00:38.479 charge it at home where I'm in charge. You can 0:00:38.560 --> 0:00:41.360 charge ten bucks to charge your car where you're in charge, 0:00:41.400 --> 0:00:43.840 and charge it on my credit card. You should charge them. 0:00:43.880 --> 0:01:01.880 I'm positive that won't work. Hi'm for Hammo cartoonists and 0:01:01.920 --> 0:01:04.759 the creator of PhD comics. Hi, I'm Daniel. I'm a 0:01:04.760 --> 0:01:08.400 particle physicist and a professor at UC Irvine, and I 0:01:08.440 --> 0:01:12.040 actually do sell charges back to the electric company. Nice 0:01:12.319 --> 0:01:15.319 solar panels. I do have solar panels, but unfortunately the 0:01:15.360 --> 0:01:18.200 electrons I produced don't end up in my car. They 0:01:18.200 --> 0:01:20.399 have to go back to the company and then I 0:01:20.520 --> 0:01:22.960 buy fresh electrons from them. I don't have one of 0:01:23.000 --> 0:01:26.880 those massive home batteries yet. Yeah, you don't want old electrons? 0:01:27.560 --> 0:01:29.640 The cool kind of stale, right. The thing, I don't know. 0:01:29.680 --> 0:01:33.319 I've had some really vintage electrons created during the Big Bang, 0:01:33.360 --> 0:01:36.960 and they were pretty tasty. Aren't all electrons created in 0:01:37.000 --> 0:01:41.000 the Big Bang? Some of them might have been, but 0:01:41.080 --> 0:01:44.640 also electrons are being created all the time, and so 0:01:44.800 --> 0:01:47.520 some electrons might be very, very fresh, and some of 0:01:47.560 --> 0:01:51.160 them might have had many, many lives before you. Do 0:01:51.160 --> 0:01:54.360 you have like an electron summerlier that tells you the 0:01:54.480 --> 0:01:57.120 vintage of electrons? And how do you taste electrons? Do 0:01:57.120 --> 0:01:59.600 you just stick your tongue in the electrical outlet or what? 0:01:59.760 --> 0:02:02.320 What advice are we giving the public here? That's a 0:02:02.360 --> 0:02:06.720 shocking suggestion, Jorge, sticking your tongue in the outlet. I'm 0:02:06.760 --> 0:02:09.440 positive that's not a good idea. But it is an 0:02:09.480 --> 0:02:12.920 interesting philosophical question of whether you could taste the age 0:02:12.919 --> 0:02:16.400 of an electron or even somehow tell its age. We 0:02:16.480 --> 0:02:19.679 don't think so, because they're quantum particles, so they're all identical. 0:02:19.840 --> 0:02:23.400 Every electron is the same as every other electron, and 0:02:23.480 --> 0:02:25.440 so there's no way to tell if an electron is 0:02:25.600 --> 0:02:29.160 fourteen billion years old or fourteen billiseconds old. Yeah, it 0:02:29.200 --> 0:02:32.519 would be kind of rude. To ask anyways, But welcome 0:02:32.560 --> 0:02:35.160 to our podcast Daniel and Jorge Explain the Universe, a 0:02:35.240 --> 0:02:38.240 production of iHeartRadio, in which we try to be positive 0:02:38.280 --> 0:02:41.320 about all the charged questions there are about the age 0:02:41.360 --> 0:02:43.760 of the universe, how big it's been getting, and what 0:02:43.919 --> 0:02:47.359 it's been eating. We like to think about everything involved 0:02:47.360 --> 0:02:50.160 in understanding the universe, from the deep nature of the 0:02:50.200 --> 0:02:52.840 fabric of space itself, all the way up to the 0:02:52.960 --> 0:02:57.840 shape and size of the universe, and everything fascinating in between. 0:02:58.280 --> 0:03:00.760 We want to tickle the curiosity that we know is 0:03:00.840 --> 0:03:04.200 inside your mind and make you wonder at this marvelous universe. 0:03:04.240 --> 0:03:06.920 Why is it this way and not some other way. 0:03:07.040 --> 0:03:09.440 That's right because it is an electrifying universe, full of 0:03:09.480 --> 0:03:12.600 amazing things happening in it, things coming together, things being 0:03:12.639 --> 0:03:15.120 pushed apart, And we like to zap all of that 0:03:15.240 --> 0:03:19.160 knowledge into your brain so that you get a small buzz. 0:03:19.680 --> 0:03:22.640 And the electricity is one of the oldest topics that 0:03:22.800 --> 0:03:26.400 humans have been thinking about. After all, it's obviously out 0:03:26.440 --> 0:03:29.120 there in the world. You don't need a superconducting super 0:03:29.120 --> 0:03:32.920 collider in order to study electricity and magnetism. You just 0:03:32.960 --> 0:03:36.080 need to watch a rainstorm and look at lightning or 0:03:36.320 --> 0:03:39.560 zap yourself as you walk across a carpet. So humans 0:03:39.560 --> 0:03:42.760 have been aware of this strange phenomena of electricity for 0:03:42.840 --> 0:03:45.360 a long long time. And wait, wait, wait, wait, they 0:03:45.400 --> 0:03:48.880 had electricity back in the steam age. How did they 0:03:48.920 --> 0:03:51.840 power their light bulbs? You know, almost all electrical generations 0:03:51.880 --> 0:03:56.280 still uses steam. It's incredible how versatile the steam engine 0:03:56.400 --> 0:04:02.920 really is. That what the electrons are always wet. I 0:04:02.920 --> 0:04:04.800 don't know what's going on with the plumbing in your 0:04:04.800 --> 0:04:07.520 house that your electrons are wet. But that does not 0:04:07.640 --> 0:04:10.960 sound like a good combination. You know, not so much 0:04:11.040 --> 0:04:14.840 wet as steamy. I get steamy electron. Well, electricity has 0:04:14.840 --> 0:04:17.839 been something that's been tickling the minds of humans and 0:04:17.960 --> 0:04:21.400 physicists and proto physicists for a long long time, you know, 0:04:21.720 --> 0:04:24.719 watching a rainstorm and wondering like wow, what is that crazy? 0:04:24.839 --> 0:04:28.080 Zapping all the way up to Benjamin Franklin trying to understand, 0:04:28.120 --> 0:04:30.559 like what's going on. It's been something we've been working 0:04:30.600 --> 0:04:33.279 on for a long time. We've made a lot of progress, 0:04:33.360 --> 0:04:37.000 and yet there's still really basic questions about how it works. 0:04:37.120 --> 0:04:39.279 You know, the origin of the word electricity, Like I 0:04:39.320 --> 0:04:42.960 wonder when humans started to think of electricity as electricity 0:04:43.000 --> 0:04:44.960 because I imagine, you know, for millions of years we 0:04:45.000 --> 0:04:47.880 saw lightning, but we didn't think it was anything different 0:04:47.920 --> 0:04:50.839 other than light or you know, strips of light. Yeah. 0:04:50.839 --> 0:04:52.960 I think there's a long history of crazy ideas to 0:04:53.040 --> 0:04:55.800 explain what we see out there, and it wasn't until 0:04:55.839 --> 0:04:57.840 a few hundred years ago that people trying to be 0:04:57.839 --> 0:05:00.240 sort of systematic about it and come up with like 0:05:00.480 --> 0:05:03.560 something you could describe as a theory to explain what 0:05:03.640 --> 0:05:06.040 was going on. You know, before that we had basically 0:05:06.120 --> 0:05:09.599 mythology zoos throwing lightning bolts and this kind of stuff. 0:05:09.960 --> 0:05:13.200 I see, so Zoos was the first electric company. I 0:05:13.240 --> 0:05:16.000 wonder if zeus charge for lightning bolts, right, I don't know. 0:05:16.240 --> 0:05:19.479 They are pretty spectacular to look at. But anyways, electricity 0:05:19.560 --> 0:05:22.120 is one of those old subjects that humans have been 0:05:22.120 --> 0:05:25.119 thinking about and wondering about, and apparently it's still something 0:05:25.120 --> 0:05:27.960 that we wonder about today. That's right. We have graduated 0:05:28.040 --> 0:05:30.880 from thinking about electricity as the product of an angry 0:05:30.920 --> 0:05:34.800 god to thinking about it as a strange, invisible fluid 0:05:34.839 --> 0:05:39.200 that flows through matter, to modern ideas that electricity is 0:05:39.279 --> 0:05:43.640 carried by tiny, little discrete charged particles, each of which 0:05:43.920 --> 0:05:47.799 carry this strange quantum label of electric charge. It doesn't 0:05:47.800 --> 0:05:52.200 sound like we've progressed much there from saying electricity is 0:05:52.200 --> 0:05:55.559 something that God throws down from the sky to something 0:05:55.560 --> 0:05:58.440 that little tiny particles have. Well, maybe emotionally we've progressed. 0:05:58.480 --> 0:06:01.359 You know, we don't think electrons are angry as Zeus was. 0:06:01.440 --> 0:06:03.599 So you know, maybe it's just a calmer theory of 0:06:03.640 --> 0:06:06.440 the universe, or maybe you just don't know if your 0:06:06.480 --> 0:06:10.040 electrons are mad at you. It could be, especially if 0:06:10.040 --> 0:06:13.039 you ask them their age. But that means that all 0:06:13.080 --> 0:06:15.200 electrons in the universe would have to be mad at you. 0:06:15.320 --> 0:06:19.039 That's like a whole universe filled with screaming, mad electrons. 0:06:19.160 --> 0:06:21.200 That's kind of terrifying. Maybe it's only the ones that 0:06:21.520 --> 0:06:23.520 you use for your car. They don't like where you're going. 0:06:24.800 --> 0:06:27.640 The ones we put to work, Yeah, exactly, just because 0:06:27.680 --> 0:06:30.800 you don't want to walk, Daniel, even if I'm walking, 0:06:30.839 --> 0:06:34.080 that uses electrons. Right, there's electrons in everything. Anytime you 0:06:34.120 --> 0:06:36.800 do some work, that's going to be electrons involved. So 0:06:37.040 --> 0:06:39.479 that's why the electron labor union is so powerful. I 0:06:39.520 --> 0:06:41.880 wonder how they hold together. But there is a lot 0:06:41.880 --> 0:06:43.960 we don't understand about the universe. And it's kind of 0:06:43.960 --> 0:06:46.560 surprising to think about the idea that there are things 0:06:46.600 --> 0:06:49.560 we don't understand about electricity. I feel like the electricity 0:06:49.600 --> 0:06:51.680 is something that we use every day. I mean, we're 0:06:51.760 --> 0:06:54.360 using it right now to record this, and also everyone 0:06:54.480 --> 0:06:56.840 is using this to listen to this podcast, and yet 0:06:56.920 --> 0:06:59.400 there are things we still don't know about it. Yeah. Well, 0:06:59.440 --> 0:07:02.400 you don't actually have to understand the universe in order 0:07:02.440 --> 0:07:05.040 to use it, right. You took advantage of gravity holding 0:07:05.040 --> 0:07:07.560 you under the earth surface long before anybody had any 0:07:07.640 --> 0:07:10.760 understanding of gravity, and even four hundreds of years when 0:07:10.760 --> 0:07:14.440 we had a pretty deep misunderstanding of gravity. So it's 0:07:14.440 --> 0:07:17.000 just sort of part of the process of science to 0:07:17.320 --> 0:07:20.920 develop these descriptions of what we see, try to explain them, 0:07:20.920 --> 0:07:23.600 and then refine them as time goes on. There will 0:07:23.640 --> 0:07:27.600 always be open questions things we don't understand. What I 0:07:27.640 --> 0:07:30.280 hope that listeners appreciate is that some of these questions, 0:07:30.280 --> 0:07:32.480 some of these things we still don't understand, are really 0:07:32.600 --> 0:07:36.040 pretty basic and have to do fundamentally with the nature 0:07:36.160 --> 0:07:39.679 of electricity. What is it anyway? Yeah, And so today 0:07:39.760 --> 0:07:47.400 on the program, we'll be tackling Could there be particles 0:07:47.680 --> 0:07:51.200 with different electric charges? That's right. We know about a 0:07:51.200 --> 0:07:53.920 few different kinds of particles with a few different kinds 0:07:53.920 --> 0:07:58.200 of electric charges. But the curious person always wonders, like, well, 0:07:58.200 --> 0:08:00.600 why is that? It? Is there more on the list? 0:08:00.720 --> 0:08:03.440 Is the universe capable of doing other things? And it 0:08:03.520 --> 0:08:06.520 just isn't? Or are there other particles out there with 0:08:06.720 --> 0:08:10.080 really weird electric charges? Yeah? I guess when we say 0:08:10.120 --> 0:08:13.560 different electric charges, we mean different charges than the electron, right, Like, 0:08:13.600 --> 0:08:15.600 could there be a particle out there with a charge 0:08:15.680 --> 0:08:17.800 that's not the same as the electron? Yeah, we actually 0:08:17.800 --> 0:08:20.200 do have a few examples of that, right, Like quarks 0:08:20.240 --> 0:08:23.560 have strange charges like two thirds and minus one third, 0:08:23.720 --> 0:08:26.520 and the electron is this charge negative one. But it's 0:08:26.560 --> 0:08:29.040 interesting to think about, like could there be particle with 0:08:29.200 --> 0:08:33.040 charges of like one millionth or one billionth or like 0:08:33.559 --> 0:08:37.320 pi or other strange numbers. There seems to be like 0:08:37.360 --> 0:08:40.120 a pattern to the electric charges, or they seem to 0:08:40.160 --> 0:08:42.720 prefer these sort of discrete units, But we don't really 0:08:42.800 --> 0:08:46.160 understand why that is. Oh, I mean we're asking today 0:08:46.200 --> 0:08:48.480 whether you can have a particle with like point zero 0:08:48.600 --> 0:08:52.040 zero zero one of the charge of the electron. Yeah, 0:08:52.200 --> 0:08:55.080 is that possible to do those particles exist? What would 0:08:55.120 --> 0:08:57.720 it mean for the universe if they did or they didn't? 0:08:58.120 --> 0:08:59.800 But you said that, we know about particles that have 0:08:59.840 --> 0:09:01.679 one third of the charge of the electron. That's a 0:09:01.760 --> 0:09:03.439 quart or some of the courts. That's right, Some of 0:09:03.440 --> 0:09:05.000 the quarks have charged one third, and some of the 0:09:05.080 --> 0:09:08.400 quirks have charged two third. Basically, every particle we've ever 0:09:08.400 --> 0:09:11.480 seen either has zero charge or some multiple of one 0:09:11.600 --> 0:09:15.240 third of the electrons charge. Nicee. So today we're asking 0:09:15.280 --> 0:09:17.520 if you can go smaller than that? Could there be 0:09:17.600 --> 0:09:20.840 particles with less than a third of the electron charge? Yeah? 0:09:20.920 --> 0:09:24.800 One fifth, one ninth, one billionth even are there limits? 0:09:24.800 --> 0:09:27.920 Is there a rule that prevents a particle from having 0:09:28.040 --> 0:09:31.599 some super tiny electric charge but not zero? And I 0:09:31.600 --> 0:09:34.320 assume that's not a question with a small answer, and 0:09:35.120 --> 0:09:37.199 maybe even answer that will shock us. That's right, it's 0:09:37.200 --> 0:09:40.400 a small question with big consequences for the philosophy of 0:09:40.480 --> 0:09:43.199 electric charges. Was usual. We were wondering how many people 0:09:43.240 --> 0:09:45.880 out there had thought about this question or wondered whether 0:09:45.960 --> 0:09:49.320 particles can have tiny electric charges. Thank you very much 0:09:49.440 --> 0:09:52.800 to our list of volunteers who answer these questions for 0:09:52.920 --> 0:09:56.680 everybody else's enjoyment and education. If you would like to 0:09:56.720 --> 0:09:59.360 contribute to your voice to this segment, please don't be shy. 0:09:59.400 --> 0:10:02.720 We don't describe. We let everybody participate. Right to me 0:10:02.840 --> 0:10:05.760 to questions at Daniel and Jorge dot com. So think 0:10:05.760 --> 0:10:08.080 about it for a second. Have you heard or think 0:10:08.280 --> 0:10:11.800 that electron can have tiny electric charges? Here's what people 0:10:11.800 --> 0:10:15.640 had to say. Yep, why not. I will accept particles 0:10:15.640 --> 0:10:22.000 of any coolure. I'm sure there's no discriminating against fractional 0:10:22.080 --> 0:10:26.000 electric charges. I would guess that particles with fractional electrical 0:10:26.080 --> 0:10:29.800 charges would be possible, given that in chemistry they have certeometry, 0:10:30.120 --> 0:10:33.839 and so it maybe does not real out the fact 0:10:33.840 --> 0:10:36.720 that this could be the same for sometime a particles. 0:10:37.280 --> 0:10:42.800 I have heard health spin as a quantum property, but 0:10:43.000 --> 0:10:48.040 never health electrical charge. So I will say no, But 0:10:48.360 --> 0:10:51.440 since you are asking it, maybe yes, my guess would 0:10:51.440 --> 0:10:55.240 be probably. I'm sure there's a law physics it says no, 0:10:55.720 --> 0:10:59.200 you have to be a plus or minus or no charge. 0:10:59.520 --> 0:11:03.239 But I don't see why you couldn't have a fractional charge. 0:11:03.360 --> 0:11:07.320 I suppose, so, yeah, I think that is the case. Today. 0:11:07.559 --> 0:11:10.880 I think we have quarks with like one third charge 0:11:11.000 --> 0:11:14.079 or two thirds charge, And I think the actual charge 0:11:14.080 --> 0:11:17.959 of an electron is some crazy fractional number and we've 0:11:18.000 --> 0:11:22.400 just chosen to assign it the value of one for convenience. 0:11:23.120 --> 0:11:27.040 So yeah, I think that's possible. Well, isn't charges caused 0:11:27.040 --> 0:11:31.559 by particles like electrons considered particles? Am I getting that wrong? 0:11:31.720 --> 0:11:34.280 I'm guessing no. Well, I'm going to walk into the 0:11:34.320 --> 0:11:38.200 obvious trap here and say that I think no particles 0:11:38.679 --> 0:11:43.480 cannot have tiny fractional electric charges. I think that an 0:11:43.480 --> 0:11:48.040 electric charge is either present, positive or negative or absent, 0:11:48.320 --> 0:11:52.840 and is an indivisible quality. I'm hoping, of course, that, 0:11:53.520 --> 0:11:56.839 true to the nature of this podcast, this obvious trap 0:11:57.080 --> 0:11:59.240 will turn out by the end of the podcast to 0:11:59.360 --> 0:12:03.600 have been an a double bluff and vindicate mind ignorance. 0:12:04.160 --> 0:12:07.120 All right, A lot of people said yes, because, of course, 0:12:07.360 --> 0:12:11.480 maybe we asked the question wrong. I think that most 0:12:11.520 --> 0:12:15.040 people don't even imagine the existence of like particles with 0:12:15.400 --> 0:12:18.559 one millions of the electric charge. Yeah, that's not something 0:12:18.640 --> 0:12:23.120 nice they open night usually wondering about. I mean, maybe 0:12:23.120 --> 0:12:27.760 one thousands, but not a million. There's some limit there. 0:12:27.800 --> 0:12:33.360 You're like, one thousands is reasonable. One millions. This crazy. Yeah, yes, 0:12:33.440 --> 0:12:35.640 that is what I think about at night. Well, you know, 0:12:35.760 --> 0:12:38.400 a way to explore the universe is just to try 0:12:38.440 --> 0:12:41.240 to be creative, to think about, like what assumptions are 0:12:41.280 --> 0:12:45.080 we making because we've only seen certain examples, what conclusions 0:12:45.080 --> 0:12:47.800 are we drawing because we've only seen a subset of 0:12:47.800 --> 0:12:51.840 what the universe can actually do. So sometimes it takes 0:12:51.840 --> 0:12:54.000 a little bit of creativity to like break out of 0:12:54.040 --> 0:12:56.800 the box we've been living in and wonder what could 0:12:56.840 --> 0:12:59.640 be outside that box. Sometimes we don't even realize the 0:12:59.720 --> 0:13:02.400 boxes that we are in. So I love this question 0:13:02.440 --> 0:13:05.360 precisely because a lot of people are like, huh, that's interesting. 0:13:05.400 --> 0:13:07.920 I never even consider that there could be other kinds 0:13:07.920 --> 0:13:10.679 of particles with weird electric charges in them. And that's 0:13:10.679 --> 0:13:13.400 what makes it exciting, because that's the best moment in physics, 0:13:13.440 --> 0:13:17.120 when we realize we've been overlooking something and maybe it 0:13:17.200 --> 0:13:19.760 shows us something new about the real universe out there. 0:13:19.800 --> 0:13:21.960 I wonder if maybe what we're asking here really is like, 0:13:22.320 --> 0:13:25.640 are there maybe particles with weird electric charges that we 0:13:25.760 --> 0:13:28.480 didn't know how weird electric charges? Is that kind of 0:13:28.480 --> 0:13:30.920 what we're asking, like, maybe there are things there are 0:13:31.000 --> 0:13:33.080 particles out there which just haven't seen them or known 0:13:33.120 --> 0:13:35.640 about them, that actually have these weird charges we just 0:13:35.720 --> 0:13:38.760 haven't noticed. Yeah, exactly. One possibility is that there's a 0:13:38.800 --> 0:13:41.640 new kind of particle out there with weird electric charges 0:13:41.760 --> 0:13:44.640 we just haven't noticed yet. The other possibility is that 0:13:44.720 --> 0:13:47.200 maybe some of the particles we do know don't actually 0:13:47.280 --> 0:13:50.920 have zero electric charge, they have very very very very 0:13:50.920 --> 0:13:54.640 small electric charges. All right, well, let's jump into this topic, Daniel. 0:13:54.720 --> 0:13:58.240 Let's start with the basics. What is an electric charge? Well, 0:13:58.320 --> 0:14:02.600 we don't really know. All thanks for joining us. See 0:14:02.600 --> 0:14:08.520 you next time. It's fun to joke about that, because 0:14:08.520 --> 0:14:11.400 that really is the answer. We don't actually know what 0:14:11.480 --> 0:14:15.840 an electric charge is physically. It's part of our description 0:14:16.040 --> 0:14:18.960 of what we see happen in the universe. So we 0:14:19.120 --> 0:14:22.480 notice that some particles that accelerated if you put them 0:14:22.520 --> 0:14:26.120 in an electric field, and other particles don't. Right, And 0:14:26.160 --> 0:14:29.040 we even have an equation that describes it. Right. Force 0:14:29.200 --> 0:14:32.160 is equal to charge times the field strength. So if 0:14:32.160 --> 0:14:34.640 a particle is accelerated when you put it in an 0:14:34.640 --> 0:14:37.400 electric field, we say that particle has charge. If a 0:14:37.440 --> 0:14:40.600 particle ignores the electric field, we say the particle has 0:14:40.680 --> 0:14:42.960 no charge. And the bigger the charge of the particle, 0:14:43.080 --> 0:14:45.720 the greater the force that it feels. But it's just 0:14:45.760 --> 0:14:48.160 sort of like our description of what we see. We 0:14:48.520 --> 0:14:52.160 put this into our mathematical story about the universe. That 0:14:52.240 --> 0:14:54.800 doesn't mean we know like what it is, right, But 0:14:54.800 --> 0:14:57.920 it's even more confusing than that, because it's kind of like, 0:14:57.920 --> 0:15:00.880 how do you define an electric field? Isn't an electric 0:15:00.920 --> 0:15:04.040 field defined as how the or this change on a 0:15:04.120 --> 0:15:06.880 particle that has charge? Yeah, exactly right. We say the 0:15:06.960 --> 0:15:10.960 fields are generated by charged particles. We don't ever even 0:15:11.040 --> 0:15:14.200 see the fields themselves, right, you can't observe a field. 0:15:14.200 --> 0:15:16.640 The only thing you can observe is the field pushing 0:15:16.760 --> 0:15:19.160 on particles. So if you want to get down to 0:15:19.200 --> 0:15:21.120 the nitty gritty, what do we actually see is that 0:15:21.320 --> 0:15:24.040 some particles push on each other, and we have this 0:15:24.080 --> 0:15:26.720 intermediate thing we call a field, which allows particles that 0:15:26.760 --> 0:15:29.000 are far away from each other to push on each other. 0:15:29.200 --> 0:15:31.920 But fundamentally, we say, some particles push on each other 0:15:31.960 --> 0:15:35.040 and some particles pull on each other, and the charges 0:15:35.080 --> 0:15:37.320 in the fields. It's just sort of like our mathematical 0:15:37.440 --> 0:15:41.000 story of what's happening there that to describe what we see. 0:15:41.600 --> 0:15:44.480 So maybe you would define a charge more accurately. As 0:15:44.520 --> 0:15:46.800 you know, if you have an electron here and an 0:15:46.800 --> 0:15:49.680 electron there, they're going to push against each other, and 0:15:49.760 --> 0:15:52.520 that push sort of depends on this thing that you 0:15:52.560 --> 0:15:54.720 call a charge. Yeah, you can put a label on 0:15:54.840 --> 0:15:58.200 every kind of particle and that label tells you how 0:15:58.280 --> 0:16:01.400 to predict whether the particle will be pushed by another 0:16:01.440 --> 0:16:04.920 particle or it's field equivalently, and that works, and it 0:16:04.920 --> 0:16:08.080 works really, really really well. It works incredibly well. It's 0:16:08.120 --> 0:16:11.160 one of the best tested theories we have in physics. 0:16:11.400 --> 0:16:14.720 We can do pages and pages of calculations to predict 0:16:14.800 --> 0:16:17.040 how electrons will push on each other and how they 0:16:17.080 --> 0:16:19.400 will shoot photons at each other, and we can do 0:16:19.440 --> 0:16:22.600 experiments to test those predictions, and the experiment and the 0:16:22.640 --> 0:16:25.960 prediction agree to like eight or nine decimal places. It's 0:16:26.040 --> 0:16:29.040 really extraordinary how accurate it is. And so you look 0:16:29.040 --> 0:16:30.720 at that theory and you're like, hm, well, if it's 0:16:30.720 --> 0:16:34.200 so accurate, maybe it's really describing what happens in the universe. 0:16:34.280 --> 0:16:37.760 Maybe this thing we invented, this idea of charge, is 0:16:37.760 --> 0:16:40.320 a property of the particle itself, not just part of 0:16:40.360 --> 0:16:43.320 our story about the particle. Right, it's sort of like 0:16:43.520 --> 0:16:46.880 mass is for gravity, Right Like, if you have two 0:16:46.920 --> 0:16:49.320 particles out there in space, they're going to attract each 0:16:49.320 --> 0:16:52.640 other depending on this thing about them called mass, And 0:16:52.720 --> 0:16:55.400 that's kind of the same for charge, right Like, if 0:16:55.440 --> 0:16:57.920 you have two particles, they're going to either attract each 0:16:57.920 --> 0:17:00.360 other or repel each other by a certain amount, pending 0:17:00.360 --> 0:17:04.639 on whether they have this thing called charge. Yes, excellent, exactly, 0:17:04.840 --> 0:17:08.160 And in particle physics we generalize this concept of charge. 0:17:08.280 --> 0:17:11.800 Do not just refer to electromagnetism, as you say. You 0:17:11.840 --> 0:17:17.200 can think about gravity in terms of gravitational charges or masses, 0:17:17.520 --> 0:17:20.720 and you can think about the strong force in terms 0:17:20.920 --> 0:17:25.280 of strong nuclear charges on quarks. Those are even more 0:17:25.320 --> 0:17:28.720 complicated because instead of having two values like plus or minus, 0:17:29.000 --> 0:17:32.600 have three values red, green, and blue. The weak force 0:17:32.880 --> 0:17:37.040 also has a kind of charge that we call weak hypercharge. 0:17:37.240 --> 0:17:40.800 So in a more general sense, charge tells you whether 0:17:40.840 --> 0:17:44.800 a particle feels a force. Like the electron has an 0:17:44.800 --> 0:17:48.320 electric charge, but it has no strong nuclear charge. It 0:17:48.359 --> 0:17:52.000 doesn't feel the strong nuclear force. A quark has both 0:17:52.040 --> 0:17:55.600 an electric charge and a strong nuclear charge, and so 0:17:55.640 --> 0:17:59.280 it feels both forces. So really, charge in general is 0:17:59.280 --> 0:18:01.840 a label about saying whether or not a particle feels 0:18:01.880 --> 0:18:05.240 that force, and it's something philosophically we like attached to 0:18:05.280 --> 0:18:08.000 the particle. We say, this is a property of this particle. 0:18:08.000 --> 0:18:11.359 The electron has the charge physically, I don't really know 0:18:11.400 --> 0:18:14.280 what that means, like where in the electron is it. 0:18:14.280 --> 0:18:17.159 It's just sort of this like ineffable quantum label we 0:18:17.240 --> 0:18:19.960 attached to it. We don't really know where it comes from, 0:18:20.000 --> 0:18:23.199 like what generates the actual charge itself? Well, I think 0:18:23.240 --> 0:18:25.639 in quantum theory and correct me if I'm wrong. But 0:18:25.760 --> 0:18:27.760 it also because it sort of has to do whether 0:18:27.880 --> 0:18:31.160 a particle interacts with certain quantum fields or done right, 0:18:31.359 --> 0:18:33.320 Like maybe that's another way to define it. If the 0:18:33.359 --> 0:18:37.480 electron doesn't interact with the strong force field, then it 0:18:37.640 --> 0:18:39.880 just doesn't have a strong charge. Yeah, I think that's 0:18:39.920 --> 0:18:41.880 another way of saying the same thing. You can think 0:18:41.880 --> 0:18:44.320 about all these quantum pictures of the world either in 0:18:44.440 --> 0:18:48.000 terms of particles that are pushing on each other or 0:18:48.040 --> 0:18:51.080 in terms of fields, because remember, these particles are actually 0:18:51.080 --> 0:18:54.800 just little wiggles in quantum fields, and those fields can 0:18:54.840 --> 0:18:58.320 sometimes talk to each other. So, for example, the electromagnetic 0:18:58.359 --> 0:19:01.360 field for which the photon is a particle can interact 0:19:01.440 --> 0:19:04.640 with or talk to any field that has charges. So 0:19:04.680 --> 0:19:07.879 the electron field of which the electron is the wiggle 0:19:08.200 --> 0:19:11.720 is the particle, right, that will interact with the electromagnetic field, 0:19:11.720 --> 0:19:14.600 and so will the field of the w boson because 0:19:14.640 --> 0:19:17.880 it has electric charge. So as you say, the fields 0:19:17.920 --> 0:19:21.320 that interact with a certain force, we say their particles 0:19:21.359 --> 0:19:23.960 have that charge, and the fields that don't, we say 0:19:23.960 --> 0:19:26.560 the particles don't have that charge. So, for example, the 0:19:26.600 --> 0:19:30.680 neutrino field, neutrinos have no electric charge. Neutrino fields and 0:19:30.720 --> 0:19:34.120 electromagnetic fields totally ignore each other. Right, So then maybe 0:19:34.160 --> 0:19:36.760 you can define charges being like whether or not auto 0:19:36.800 --> 0:19:40.720 particle interacts with the electromagnetic field. Yeah, for the electric charge, 0:19:41.040 --> 0:19:43.800 And in terms of like particle theory, they often talk 0:19:43.840 --> 0:19:46.600 about it as coupling. The electric charge is the way 0:19:46.600 --> 0:19:50.919 that the photon field couples to the electron field. How 0:19:51.000 --> 0:19:53.280 those two fields sort of like let energy slide back 0:19:53.320 --> 0:19:55.600 and forth between them. I feel like we're getting a 0:19:55.600 --> 0:19:59.520 little steaming out there. Are we back to talking about 0:19:59.520 --> 0:20:03.919 steamia not steaming a not safe for workway? You know, 0:20:03.960 --> 0:20:06.920 we're just talking about connections. We're just talking about energy 0:20:07.000 --> 0:20:09.560 sliding from one kind of feel to the other. All right, well, 0:20:09.880 --> 0:20:12.000 what sounds like we kind of have a definition of 0:20:12.040 --> 0:20:14.320 what charge is. We just don't know where it comes 0:20:14.320 --> 0:20:16.280 from kind of right, That's the thing, like, we don't 0:20:16.280 --> 0:20:19.119 know why some particles interact with the electropicnet feels and 0:20:19.160 --> 0:20:21.320 why some don't. That's right. We have a very effective 0:20:21.320 --> 0:20:24.040 description of it, but we don't know why some particles 0:20:24.080 --> 0:20:26.720 have it, what the rules are for what charges you 0:20:26.760 --> 0:20:29.760 are allowed to have, and where it comes from at all. Yeah, 0:20:29.760 --> 0:20:32.960 I guess some particles just have that spark and others 0:20:33.000 --> 0:20:35.479 some particles just have a positive attitude. All right, Well, 0:20:35.560 --> 0:20:38.439 let's get into a little bit of the history of 0:20:38.480 --> 0:20:40.840 this idea of an electric charge. Where did it come from? 0:20:40.880 --> 0:20:42.639 How did humans start to figure this out? And then 0:20:42.680 --> 0:20:46.720 let's get into the bigger question of whether electrons or 0:20:46.760 --> 0:20:50.840 things with electrical charge can have tiny, almost imperceptible charges. 0:20:50.920 --> 0:21:05.520 But first let's take a quick break or I we're 0:21:05.560 --> 0:21:09.080 talking about charges, and we're charging ahead here with this topic, 0:21:09.520 --> 0:21:14.040 talking about whether electrons or charged particles that have the 0:21:14.040 --> 0:21:17.320 fuel electricity can have electrical charges that maybe have been 0:21:17.400 --> 0:21:20.240 escaping our notice for thousands of years. So Daniel, maybe 0:21:20.240 --> 0:21:22.159 step us through here a little bit on the history 0:21:22.200 --> 0:21:25.399 of charges. When did we start noticing that some things 0:21:25.440 --> 0:21:29.760 have electrical charge? So we certainly had noticed the properties 0:21:29.800 --> 0:21:33.919 of electricity for a long long time, right, static electricity 0:21:33.960 --> 0:21:37.040 and lightning, these are things everybody was aware of, and 0:21:37.200 --> 0:21:41.640 until around the mid seventeen hundreds, the idea to explain 0:21:41.760 --> 0:21:45.920 these things was dominated by concepts like effluvium or this 0:21:46.080 --> 0:21:51.080 basically this two fluid theory of electricity and magnetism. It 0:21:51.200 --> 0:21:55.280 was like this invisible fluid that flowed through objects, two 0:21:55.320 --> 0:21:59.240 different kinds of invisible liquids flowing through objects, one positive, 0:21:59.280 --> 0:22:02.320 one negative, that could cancel each other out right, Because 0:22:02.400 --> 0:22:04.359