WEBVTT - Listener Questions 4 0:00:08.080 --> 0:00:10.720 Hey, Daniel, what's been in our inbox lately? Well, we 0:00:10.760 --> 0:00:14.040 get the usual stuff, people with minor corrections, people with 0:00:14.480 --> 0:00:18.320 you know, cosmic questions, people asking me for to send 0:00:18.320 --> 0:00:20.639 them special stuff for Father's Day. So you said people 0:00:20.640 --> 0:00:23.079 are asking about Father's Day. Yes, some people right in 0:00:23.320 --> 0:00:25.599 I like this because they're not actually fans of our show, 0:00:25.800 --> 0:00:27.760 but their dad or their mom is a fan of 0:00:27.760 --> 0:00:29.960 the show, and they want us to send a special 0:00:30.000 --> 0:00:33.159 Father's Day or Mother's Day message to their parents who listens. 0:00:33.200 --> 0:00:36.159 So it's like young, cool, hip people saying, Hey, my 0:00:36.240 --> 0:00:38.919 dad likes your show, and I have no ideas for 0:00:38.960 --> 0:00:41.480 any Father's Day's gifts. So do we charge for these 0:00:41.560 --> 0:00:44.320 or we don't charge for these because we're nice guys 0:00:44.880 --> 0:00:47.839 and we like helping people, and we're also fathers, and 0:00:47.920 --> 0:00:49.879 so I want to give a special shout out to 0:00:50.040 --> 0:00:53.279 Paul truth Low, whose daughter Caitlin asked us to give 0:00:53.320 --> 0:00:56.520 you a special Father's Day message. So happy Father's Day, Paul, 0:00:56.720 --> 0:01:15.720 and uh roll Tide, I'm supposed to say. Also, Hi, 0:01:15.760 --> 0:01:18.160 I'm Poor Hay, I'm a cartoonists and the creator of 0:01:18.319 --> 0:01:22.200 PhD Comics. Hi I'm Daniel Whitson, I'm a particle physicist 0:01:22.280 --> 0:01:25.280 by day and a podcaster by any other time I know. 0:01:25.360 --> 0:01:28.160 Welcome to our podcast Daniel and Jorge Explain at Universe, 0:01:28.200 --> 0:01:31.200 a production of I Heart Radio in which we really do, 0:01:31.400 --> 0:01:35.160 honestly try to answer questions about physics, Questions that we have, 0:01:35.319 --> 0:01:38.440 questions that you have, Questions that we just randomly float 0:01:38.480 --> 0:01:41.120 into our minds some days. Yeah, and if you actually 0:01:41.160 --> 0:01:44.760 send us a question, either at questions at Daniel and 0:01:44.880 --> 0:01:47.560 Jorge dot com or any one of our social media 0:01:47.680 --> 0:01:51.440 channels like Instagram or Twitter or Facebook, we will actually 0:01:51.520 --> 0:01:54.920 get to your question and maybe even talk about it 0:01:55.080 --> 0:01:58.240 on the podcast. That's right, because when you have a question, 0:01:58.400 --> 0:02:01.280 probably other people have the same question. And that's the 0:02:01.320 --> 0:02:06.000 wonderful thing about having people suggest questions, because sometimes there's 0:02:06.040 --> 0:02:08.359 an angle to something that we haven't thought of because 0:02:08.600 --> 0:02:11.520 we come at it from a scientific perspective, and seeing 0:02:11.520 --> 0:02:13.360 it from the point of view of the audience helps 0:02:13.400 --> 0:02:17.320 us really explain these things, really get down and untangle 0:02:17.400 --> 0:02:19.320 all those mysteries that you have in your mind, because 0:02:19.440 --> 0:02:21.240 our goal is at the end of this that you 0:02:21.240 --> 0:02:24.320 have a crystal clear picture what's going on in this universe. 0:02:24.360 --> 0:02:26.560 And if you send us a question that stumps Daniel, 0:02:27.000 --> 0:02:29.560 you actually get a prize, right, Daniel, Yeah, banana cake. 0:02:29.600 --> 0:02:31.600 I don't know. It's a podcast has to be audio, 0:02:31.680 --> 0:02:34.040 So the sound of Jorgey eating a banana cake that 0:02:34.120 --> 0:02:36.760 Daniel made. How about that? Some Rader shows give you 0:02:36.760 --> 0:02:39.880 your phone message, they'll record your your voicemail message. We 0:02:39.960 --> 0:02:44.919 will record one of the hosts eating bananas. What could 0:02:44.960 --> 0:02:46.600 be better than that? Yeah? Well, hey, that could be 0:02:46.680 --> 0:02:48.960 a good ring tone, right, that could be a good ringtowne. Hey, 0:02:49.000 --> 0:02:50.680 I got a call coming and how do you know 0:02:50.760 --> 0:02:54.840 it sounds like something's eating in your pocket. Yeah, that's right. 0:02:54.840 --> 0:02:57.080 If you're really kind of personally doesn't like peop believing 0:02:57.120 --> 0:02:59.840 your voicemails, this is this is the contest for you 0:03:00.520 --> 0:03:04.240 right here. That's right, that's right. No, seriously, I would 0:03:04.240 --> 0:03:06.960 love to get a question that stumps me. Um. I 0:03:07.080 --> 0:03:09.280 do get questions A lot of times. I get questions 0:03:09.320 --> 0:03:11.960 I've never heard before, and that's a wonderful experience because 0:03:12.000 --> 0:03:14.080 you know, there's a standard as the questions people ask. 0:03:14.320 --> 0:03:16.360 But then there's a question I'd never even thought to 0:03:16.360 --> 0:03:19.520 ask before, and that's wonderful because it gives me a 0:03:19.560 --> 0:03:22.360 little view into the mind of the question er. I 0:03:22.400 --> 0:03:25.040 have to think what did they understand or what was 0:03:25.080 --> 0:03:27.560 going on in their head that inspired this question, so 0:03:27.600 --> 0:03:29.280 that I can then figure out how to guide them 0:03:29.280 --> 0:03:32.000 from there to a clear picture of what's actually happening. 0:03:32.280 --> 0:03:34.359 And that's the challenge of teaching, and that's what I 0:03:34.400 --> 0:03:36.480 really love about that. So these are questions you hadn't 0:03:36.480 --> 0:03:40.200 even thought anyone could ask or would ask. Yeah, I'll 0:03:40.200 --> 0:03:43.800 give you an example. Um, I give demonstrations at elementary 0:03:43.840 --> 0:03:46.840 school sometimes and we use like liquid nitrogen and all 0:03:46.840 --> 0:03:49.440 sorts of stuff too, you know. Um, one time we 0:03:49.560 --> 0:03:51.760 froze bananas and shattered it on the ground and the 0:03:51.840 --> 0:03:54.840 kids thought that was cool, and afterwards were open for questions. 0:03:54.880 --> 0:03:58.520 Wait wait, wait, you shattered bananas. That's right, some bananas 0:03:58.560 --> 0:04:00.440 were harmed in the making of this pod cast. I 0:04:00.440 --> 0:04:04.760 have to oh, man, my heart is bleeding, Daniel. But 0:04:04.960 --> 0:04:07.560 afterwards we were open for questions, and some kid raised 0:04:07.560 --> 0:04:11.680 his hand and he says, if lightsabers were real, would 0:04:11.680 --> 0:04:15.280 they be made of liquid nitrogen? And I thought, I 0:04:15.320 --> 0:04:17.960 have no idea how to answer that question, you know, like, 0:04:18.480 --> 0:04:20.760 where do you even begin. You rolled your eye, You're like, 0:04:20.839 --> 0:04:25.159 obviously they're made out of hyper crystal. Wikid do your research. 0:04:25.600 --> 0:04:28.640 I had not done my research on fictional universes and 0:04:28.640 --> 0:04:31.599 how science might work in that fictional universe. But I 0:04:31.640 --> 0:04:34.679 love that he connected two things he found amazing liquid 0:04:34.760 --> 0:04:38.359 nitrogen and lightsabers, and thought maybe these are the same things. 0:04:38.760 --> 0:04:40.640 And actually we get a lot of emails like that. 0:04:40.640 --> 0:04:43.039 They're like, hey, today you guys talked about the mystery 0:04:43.080 --> 0:04:46.720 of you know, dark matter. Maybe that's the same thing 0:04:47.240 --> 0:04:50.480 as this other mystery. Like after our time episode, a 0:04:50.480 --> 0:04:53.359 lot of people wrote in and said, maybe dark energy 0:04:53.480 --> 0:04:56.560 is just a mistake of how we observe time, and 0:04:56.600 --> 0:05:00.000 time doesn't just move forward constantly. It's sort of stutter steps, 0:05:00.000 --> 0:05:02.799 and that's dark energy. People love to connect to mysteries 0:05:02.800 --> 0:05:05.039 and try to solve them at once. So you know 0:05:05.080 --> 0:05:07.360 that little boy in the class, he really exemplified the 0:05:07.440 --> 0:05:10.479 kinds of questions that that listeners ask. We're all just 0:05:10.600 --> 0:05:14.679 little Star Wars fans inside. That's right, that's right. Yeah, 0:05:14.760 --> 0:05:17.880 Well today we are answering your questions on the podcast. 0:05:18.240 --> 0:05:28.560 Today's episode is about listener questions Part four, right or 0:05:28.720 --> 0:05:31.400 are we up to part pie? Are we sort of 0:05:31.480 --> 0:05:36.240 this version? Pie? I think our podcasts are integer numbered, Yeah, 0:05:36.480 --> 0:05:38.800 so this would be number four. It would be awesome 0:05:38.839 --> 0:05:41.320 to have a point one four of a podcast, but 0:05:41.360 --> 0:05:43.120 I'm not sure how do you pull that off? All right, 0:05:43.200 --> 0:05:47.479 So today we have three interesting questions from listeners from 0:05:47.520 --> 0:05:51.200 all across the world, right or at least the United States. Oh, 0:05:51.200 --> 0:05:53.320 I think some of them are international. They don't always 0:05:53.360 --> 0:05:55.359 tell us where they come from, but based on the accent, 0:05:55.560 --> 0:05:57.400 I don't think all of these come from the Southwest 0:05:57.480 --> 0:05:59.880 the United States, which seems to be are a big 0:06:00.480 --> 0:06:03.920 hotbed for fans over our show. No, it was just random. 0:06:04.000 --> 0:06:06.080 Last time I happened to pick three questions which all 0:06:06.160 --> 0:06:09.760 like came from the south I was totally just random. 0:06:09.800 --> 0:06:12.800 But today we have three pretty cool questions from listeners. 0:06:12.839 --> 0:06:16.400 One is about gravity, another one about dark matter, and 0:06:16.440 --> 0:06:20.359 the other one is about the nuclei of Adam, Like 0:06:20.440 --> 0:06:22.480 how do they stay together? And why don't we all 0:06:22.560 --> 0:06:26.200 just explode into balls of nuclear explosions? Maybe we will. 0:06:26.760 --> 0:06:29.680 You'll find out on today's episode. I think people um 0:06:29.839 --> 0:06:32.880 might already know the answer. But teaser, you're you're okay 0:06:32.920 --> 0:06:35.160 for the next couple of seconds. You'll survive long enough 0:06:35.160 --> 0:06:37.200 to hear the end of this episode at the very least, 0:06:37.240 --> 0:06:39.760 and then you can you can then explode view like 0:06:40.200 --> 0:06:43.960 from knowledge? Do you think anybody has ever perished while 0:06:44.040 --> 0:06:46.600 listening to our episode? That just dark thoughts just entered 0:06:46.640 --> 0:06:49.800 my head. Oh my god, let's let's cut that out. 0:06:51.720 --> 0:06:54.120 Can you imagine being the last thing anybody ever heard 0:06:54.120 --> 0:06:58.400 in their life for making a joke about bananas? It 0:06:58.520 --> 0:07:03.640 blew their minds, banded their idea of what a joke 0:07:03.680 --> 0:07:07.560 could be, and it's just overwhelmed their neural network. Yeah. 0:07:07.640 --> 0:07:09.800 I don't know if that means the joke was amazing 0:07:10.120 --> 0:07:12.480 so good that they couldn't take it, or they're just like, 0:07:12.520 --> 0:07:16.200 you know what, I'm done after that. I can't take 0:07:16.200 --> 0:07:18.760 anymore people get paid to say those kinds of jokes. 0:07:18.800 --> 0:07:21.560 Then I'm out of here. There's no amazing to go on. 0:07:22.080 --> 0:07:25.640 That's right, goodbye, cool, unfunny world. Well help, neither of 0:07:25.680 --> 0:07:29.280 these things happen to you, our dear listeners. But our 0:07:29.320 --> 0:07:32.040 first question comes from Florence from Texas, and she has 0:07:32.080 --> 0:07:37.320 a question about how gravity could um keep the Earth 0:07:37.320 --> 0:07:39.400 in orbit. Here's what you had to say. I have 0:07:39.440 --> 0:07:43.080 a question about gravity. You've described it before as the 0:07:43.120 --> 0:07:46.560 weakest force, and you said in fact that it's so 0:07:46.640 --> 0:07:49.840 weak that when you're picking up an object with a magnet, 0:07:50.440 --> 0:07:54.240 you're overpowering the entire Earth's gravity, So that's pretty weak. 0:07:54.760 --> 0:07:56.960 My problem is when I start thinking about the objects 0:07:57.000 --> 0:08:00.200 and the Kuiper Belt, they're thirty two fifty astronomer gold 0:08:00.240 --> 0:08:04.200 units away and that's billions and billions of miles, and 0:08:04.320 --> 0:08:06.480 yet the Sun's gravity is still able to keep them 0:08:06.480 --> 0:08:09.240 in orbit. And that just gives me the impression that 0:08:09.280 --> 0:08:13.400 gravity is really strong, not weak. So those two thoughts 0:08:13.440 --> 0:08:16.240 really don't go together. Um, would you help me with that? 0:08:16.320 --> 0:08:18.720 All right? Thank you, Florence from Texas. So that's a 0:08:18.800 --> 0:08:22.120 pretty interesting question, right, Daniel. Is that we often mentioned 0:08:22.120 --> 0:08:25.000 on the show that gravity is the weakest force, and 0:08:25.040 --> 0:08:28.600 it's actually super duper duper weak. But at the same time, 0:08:29.160 --> 0:08:31.120 I think maybe a lot of listeners are thinking, but 0:08:31.280 --> 0:08:34.600 weight of gravity is a weak how is it keeping 0:08:34.679 --> 0:08:38.200 the Earth going around in orbit and other planets in Jupiter? 0:08:38.440 --> 0:08:42.120 And how is it such an amazing, an incredible force 0:08:42.160 --> 0:08:44.319 in the universe. It is an amazing, incredible force in 0:08:44.360 --> 0:08:46.760 the universe, And you're right to wonder about that, because 0:08:46.800 --> 0:08:48.920 as you look out into the night sky, you think about, 0:08:49.000 --> 0:08:51.840 like all the structures in the universe, the Solar system 0:08:51.880 --> 0:08:54.000 with the planets going around the Sun, and even the 0:08:54.000 --> 0:08:57.960 galaxy and the structures of galaxies and the superclusters, all 0:08:58.000 --> 0:09:01.640 of that is determined by gravity, right, So gravity seems 0:09:01.679 --> 0:09:04.360 to have a huge role in organizing the way the 0:09:04.440 --> 0:09:07.600 universe works, right, And and the way we discovered dark 0:09:07.600 --> 0:09:10.840 matters through gravity. And so if you just looked at it, 0:09:10.840 --> 0:09:12.559 you say, well, gravity is one of the most important 0:09:12.559 --> 0:09:15.880 forces because it shapes the whole universe. So then to 0:09:15.920 --> 0:09:18.360 hear somebody say actually, gravity is the weakest force in 0:09:18.360 --> 0:09:21.160 the universe, it does seem like a strong contradiction, right, 0:09:21.200 --> 0:09:24.080 it It doesn't make sense in your mind, because how 0:09:24.080 --> 0:09:26.240 can it be the weakest force and also be the 0:09:26.280 --> 0:09:28.840 thing that shapes everything else? Right, It's kind of like 0:09:28.880 --> 0:09:32.679 the organizing force in the universe, right, It organizes planets 0:09:32.760 --> 0:09:37.920 into solar systems, and solar systems into galaxies and galaxies 0:09:37.960 --> 0:09:40.520 in two clusters. Like if we didn't have gravity, everything 0:09:40.520 --> 0:09:43.520 which is a fly fly away and fly apart. Yeah, 0:09:43.520 --> 0:09:45.040 that's right, we wouldn't have any of the good stuff 0:09:45.040 --> 0:09:46.840 that we have without gravity. So we own a big 0:09:46.840 --> 0:09:48.760 thanks to gravity. And I like the way you said 0:09:48.800 --> 0:09:51.000 it's I sort of organized these things. I think that's 0:09:51.000 --> 0:09:54.360 one of the big ideas to understand how gravity can 0:09:54.360 --> 0:09:56.880 play such a big role and be so weak. It's 0:09:56.880 --> 0:09:58.920 sort of like the way you make a big mess 0:09:58.920 --> 0:10:00.760 in your house and then you come back home and 0:10:00.800 --> 0:10:03.440 your mom is organized the living room or whatever. Right, 0:10:03.559 --> 0:10:06.520 some mysterious forces organized it while while you were gone. 0:10:06.720 --> 0:10:10.720 Your mom still cleans your house. That's pretty good. Know what, 0:10:10.800 --> 0:10:12.800 your mom cleans my house where hey, she doesn't. She 0:10:12.840 --> 0:10:16.960 doesn't clean yours. She flies from Panama every every week 0:10:17.000 --> 0:10:20.280 and clean your house and she doesn't even call me. 0:10:20.320 --> 0:10:24.440 Oh my god, Maybe because I didn't celebrate Mother's Day. Yeah, exactly, 0:10:24.520 --> 0:10:26.800 Well you should have sent her banana cake. Um No. 0:10:26.920 --> 0:10:28.920 But the point I wanted to make, the actual physics point, 0:10:28.960 --> 0:10:32.240 not a joke, is that gravity is a force that's 0:10:32.240 --> 0:10:34.600 sort of left over like all the other forces in 0:10:34.600 --> 0:10:38.560 the universe. Electromagnetism, the strong force, the weak force. All 0:10:38.600 --> 0:10:41.560 these forces are so powerful that they get kind of 0:10:41.640 --> 0:10:45.840 naturally balanced. Like there's no electrostatic force or electromagnetic force 0:10:45.880 --> 0:10:48.640 between the Earth and the Sun. Why because if there were, 0:10:48.760 --> 0:10:52.160 it would be incredibly powerful and it would balance itself 0:10:52.400 --> 0:10:55.320 the way like lightning is a balancing of the electrons 0:10:55.360 --> 0:10:58.320 between the Earth and the sky. Right, anytime there's any 0:10:58.360 --> 0:11:01.880 imbalance June, there's a huge bolt of lightning to balance 0:11:01.960 --> 0:11:04.240 these things out. And so as a result, there is 0:11:04.280 --> 0:11:09.080 no electromagnetic force between these huge celestial objects, and so 0:11:09.200 --> 0:11:12.440 it's gravity. Gravity can't be balanced though. It's the one 0:11:12.760 --> 0:11:16.280 force that cannot be neutralized because it only has mass. 0:11:16.280 --> 0:11:19.200 There's no negative mass to balance it out. So after 0:11:19.280 --> 0:11:21.680 all the other forces have made their big mess, gravity 0:11:21.720 --> 0:11:23.320 sort of left to pick up the pieces. It's the 0:11:23.360 --> 0:11:25.319 only thing left on the playing field, right. Well, I 0:11:25.360 --> 0:11:27.480 think it's important to maybe mention that when we say 0:11:27.600 --> 0:11:32.679 it's the weakest force, it's a relative assessment, right, Like 0:11:32.720 --> 0:11:36.920 we're we're not saying gravity is weak, it's just weak 0:11:37.320 --> 0:11:40.040 relative to the electromagnetic force. Well I'm saying it. No, 0:11:40.120 --> 0:11:43.600 I'm saying gravity is super weak. It's embarrassing. It's puny's pathetic, 0:11:44.160 --> 0:11:47.040 but only only because you know other forces that are stronger. 0:11:47.120 --> 0:11:48.839 But if you didn't know the other forces, you'd be like, 0:11:48.920 --> 0:11:51.240 oh my god. Gravity is what keeps the Earth from 0:11:51.240 --> 0:11:53.200 going around the Sun, and the Earth is pretty big, 0:11:53.280 --> 0:11:55.880 so it's like a huge force. You just know that 0:11:55.960 --> 0:11:58.560 in comparison, it's kind of wimpy. I guess, so, I mean, 0:11:58.640 --> 0:12:00.840 I think in comparison is really the only metric we have. 0:12:01.480 --> 0:12:05.000 It's also important to recognize how much weaker it is. 0:12:05.520 --> 0:12:09.000 Like if you took electrons, for example, and you asked, like, 0:12:09.120 --> 0:12:12.520 what is the force of their electrostatic repulsion compared to 0:12:12.559 --> 0:12:17.800 their gravitational um attraction, then the difference is like ten, 0:12:18.200 --> 0:12:23.839 with thirty three zeros after it. So you know, millions, billions, trillions, quadrillions. 0:12:23.880 --> 0:12:26.920 You run out of numbers really quick. It's a huge difference. 0:12:26.960 --> 0:12:30.040 It's like a completely different scale, right, So you're saying, 0:12:30.040 --> 0:12:32.600 if I have an electron and maybe a proton, they're 0:12:32.640 --> 0:12:38.080 both being attracted by two forces, gravity and electromagnetism. But 0:12:38.120 --> 0:12:42.040 you're saying the electromagnetism is thirty two orders of magnetudes 0:12:42.040 --> 0:12:45.880 stronger than the gravitational force between them. Yeah, exactly, They're 0:12:46.000 --> 0:12:51.280 totally different scales, exactly. Electromagnetism, I mean, it's jatillion. What 0:12:51.280 --> 0:12:56.280 what's the word for thirty zeros? It's an alien you 0:12:56.320 --> 0:13:00.559 go be a zillion um. It's so much bigger. If 0:13:00.640 --> 0:13:02.320 you don't even really want to describe them in the 0:13:02.360 --> 0:13:05.040 same level. It's like, you know, the mass of the 0:13:05.080 --> 0:13:07.679 Earth versus the math of mass of a penny or something. 0:13:07.720 --> 0:13:10.040 You know, you don't you don't call a penny a 0:13:10.120 --> 0:13:12.640 celestial object because it isn't right so tiny, you just 0:13:12.720 --> 0:13:15.600 sort of round it up into the earth um. Anyway, 0:13:15.880 --> 0:13:19.400 the reason that gravity can still play on the field 0:13:19.440 --> 0:13:21.640 at all is that these other forces are so strong 0:13:21.679 --> 0:13:24.240 that they balance each other out, and gravity you can't 0:13:24.280 --> 0:13:27.200 do that, right, Like we were talking about one electron 0:13:27.320 --> 0:13:30.079 another electron, they repel each other, whereas an electron or 0:13:30.080 --> 0:13:33.560 a proton they attract each other. Right, Gravity only makes 0:13:33.600 --> 0:13:37.679 attractive forces. Everything with mass feels gravity and it attracts itself. 0:13:37.760 --> 0:13:40.640 There's no way to have repulsive gravity. And we did 0:13:40.679 --> 0:13:42.960 a whole podcast episode about anti gravity. As far as 0:13:42.960 --> 0:13:45.480 we know, it's not possible. So there's no way to 0:13:45.480 --> 0:13:48.600 balance gravity out. After everybody else has done their stuff 0:13:48.640 --> 0:13:51.320 and and been neutralized, gravity is left over, and so 0:13:51.360 --> 0:13:54.240 then it gets to organize the universe. Yeah, I was thinking, 0:13:54.280 --> 0:13:57.439 like maybe an interesting picture is to imagine a proton 0:13:58.440 --> 0:14:01.800 in the Sun and then imagine a proton and an 0:14:01.840 --> 0:14:06.199 electron on Earth. It's not that there's no electromagnetic force 0:14:06.280 --> 0:14:10.320 between that proton and this proton and electron. It's just 0:14:10.400 --> 0:14:12.960 that that the proton in the sun's pulling the electron 0:14:12.960 --> 0:14:15.320 towards the Sun, but it's also pushing the proton away 0:14:15.320 --> 0:14:19.040 from the Sun with the exact same force. So our 0:14:19.080 --> 0:14:21.720 pair of proton and electron here on Earth just doesn't 0:14:21.760 --> 0:14:25.480 feel any electro metnetic force with that proton in the Sun, 0:14:25.760 --> 0:14:28.880 but it does feel gravity, yeah, exactly. And you know, 0:14:28.920 --> 0:14:31.240 there's lots of protons and electrons in the Sun, and 0:14:31.280 --> 0:14:33.680 so they all work, they all arrange themselves in such 0:14:33.680 --> 0:14:36.440 a way that there's effectively no net force, and there's 0:14:36.480 --> 0:14:39.400 no way to arrange the protons electrons to get no 0:14:39.560 --> 0:14:42.400 net gravitational force. There's just no way to do that. 0:14:42.480 --> 0:14:44.200 But I think it's interesting to think about. It's not 0:14:44.240 --> 0:14:47.640 that there's no force, it's just that there's no net force, 0:14:47.720 --> 0:14:51.400 you know, like it is pushing and pulling as electromagnetically 0:14:51.480 --> 0:14:54.560 the Sun, it all just sort of cancels out. Yeah, yeah, 0:14:54.720 --> 0:14:56.800 like it's pushing on a proton and it's pushing on 0:14:56.840 --> 0:14:59.680 an electron the opposite direction, right, But because our proton 0:14:59.760 --> 0:15:02.280 and the electron are holding on together, they're they're not 0:15:02.320 --> 0:15:04.560 going anywhere. Yeah, that's that's a fine way to think 0:15:04.560 --> 0:15:07.080 about it. Um. And I think the other thing to 0:15:07.120 --> 0:15:10.920 recognize is that gravity is really really weak, but the 0:15:10.960 --> 0:15:14.720 Sun is really really big, like really really really really big, 0:15:15.160 --> 0:15:18.200 so it can have a pretty strong gravitational effect on 0:15:18.200 --> 0:15:20.520 the Earth even though gravity is weak, because it just 0:15:20.600 --> 0:15:24.240 has so much mass, right, And so yeah, gravity is weak, 0:15:24.280 --> 0:15:27.120 but the Sun is so big that those two factors 0:15:27.240 --> 0:15:29.080 kind of cancel each other out and it becomes an 0:15:29.080 --> 0:15:33.400 important force. Yeah, the weakness accumulates exactly. You have like 0:15:33.680 --> 0:15:36.600 a billion people all whispering your name, it's going to 0:15:36.680 --> 0:15:39.400 add up to a huge scream, right, And that's the 0:15:39.440 --> 0:15:41.840 way it is with gravity. All those protons in the 0:15:41.880 --> 0:15:45.200 Sun are giving a tiny little tug on the protons 0:15:45.200 --> 0:15:48.920 and electrons on Earth gravitationally. But there's so many protons 0:15:48.920 --> 0:15:50.760 in the Sun that it's enough to pull a whole 0:15:50.840 --> 0:15:53.360 planet around in a circle. Right. It's not a small 0:15:53.360 --> 0:15:55.960 amount of force to keep the Earth in orbit, right, 0:15:56.000 --> 0:15:58.240 It's a huge force that keeps the Earth in orbit. 0:15:58.600 --> 0:16:00.800 Oh man, you just gave me a new nightmare. To 0:16:00.840 --> 0:16:08.480 imagine a billion people whispering my name. That is so bizarre. 0:16:08.240 --> 0:16:12.280 That is kind of creepy. Actually, yes, that doesn't where 0:16:12.320 --> 0:16:15.920 that came from. Hey, let's all whisper Paul's name for 0:16:15.920 --> 0:16:20.720 for father's sake, for father's days, didn't heal sense of 0:16:20.800 --> 0:16:24.080 disturbance in the force when that happens. Everybody listened to 0:16:24.080 --> 0:16:29.280 me to this right now, go Paul, Paul, Happy Father's Day, Paul, 0:16:32.320 --> 0:16:40.040 your daughter is awesome. Cool. All right, that's um Florence's 0:16:40.120 --> 0:16:43.760 question about gravity, and so the answer Florence is that 0:16:44.080 --> 0:16:48.520 gravity is weak, but it's also happening on such a 0:16:48.600 --> 0:16:52.840 large scale that it does. It is enough to pool 0:16:52.880 --> 0:16:56.120 planets and keep galaxies together, that's right. And after all 0:16:56.160 --> 0:16:58.960 the other forces have done their business, gravity is left 0:16:58.960 --> 0:17:02.400 over to organize the universe because it can't be balanced out. 0:17:02.640 --> 0:17:04.879 All right, Well, that's one question, and we'll get to 0:17:05.200 --> 0:17:07.680 the two other questions we have today about dark matter 0:17:08.040 --> 0:17:12.119 and atomic nuclei. But first let's take a quick break. 0:17:25.200 --> 0:17:27.639 Our second question of the day comes from Margie, who 0:17:27.680 --> 0:17:31.040 has a question about dark matter. Hey, Daniel and Jorge, 0:17:31.200 --> 0:17:34.440 this is Marchie. My question is how does dark matter 0:17:34.480 --> 0:17:36.879 influence the movement of the planets in the Solar System? 0:17:37.000 --> 0:17:38.959 Does it make them all orbit at the same speed 0:17:39.320 --> 0:17:42.920 and if so, all right, that's a pretty interesting question. Um, 0:17:43.280 --> 0:17:45.600 we talked, we've talked a lot about dark matter in 0:17:45.640 --> 0:17:49.359 this podcast and how it's there. It's all around us, 0:17:49.480 --> 0:17:53.760 it's in the center of galaxies, right all over the galaxy, 0:17:53.800 --> 0:17:58.879 and it's constantly pulling on everything and helping galaxy stay together. Yeah, 0:17:58.920 --> 0:18:01.240 this is a wonderful question. And because this is a 0:18:01.320 --> 0:18:03.360 kind of question that shows me that people are doing 0:18:03.359 --> 0:18:06.560 physics in their mind, right, they says, you've learned how 0:18:06.640 --> 0:18:10.440 dark matter influences how galaxies rotate, Like we discovered dark 0:18:10.440 --> 0:18:13.600 matter because we saw the galaxies were spinning too fast 0:18:13.640 --> 0:18:16.159 and they need more gravity to hold them together. So 0:18:16.200 --> 0:18:19.000 that means that dark matter makes enough gravity to be 0:18:19.040 --> 0:18:22.040 like noticeable about how things spin. Right, So that the 0:18:22.160 --> 0:18:24.480 natural physics thing to do is to say, okay, I 0:18:24.480 --> 0:18:27.560 have my new understanding, let me apply it to something else. 0:18:27.880 --> 0:18:30.880 Does that make sense? And this listener obviously thought, well, 0:18:30.920 --> 0:18:34.320 if there's dark matter enough to affect the galaxy spinning, 0:18:34.560 --> 0:18:36.520 why can't we notice it here on Earth? Like, why 0:18:36.520 --> 0:18:39.200 can't we do that same measurement and see like, hey, 0:18:39.240 --> 0:18:42.119 the Earth is going around the Sun too fast? Can't 0:18:42.119 --> 0:18:44.920 we detect the dark matter in our Solar system by 0:18:44.960 --> 0:18:47.800 looking at how the Earth orbits the Sun the same 0:18:47.840 --> 0:18:49.720 way we look at how the Sun orbits the center 0:18:49.720 --> 0:18:52.440 of the galaxy. So it's really a genius question. Oh, 0:18:52.480 --> 0:18:55.600 I see. The question is is the Earth going around 0:18:55.640 --> 0:18:58.600 the Sun faster than it should be if dark matter 0:18:58.840 --> 0:19:02.520 didn't exist? Because imagine, for example, that there wasn't just 0:19:02.600 --> 0:19:04.720 the Sun in the center of the Solar system. Imagine 0:19:04.720 --> 0:19:06.720 there were five sons, but you can only see the 0:19:06.760 --> 0:19:08.640 one of them, right, and the other ones were made 0:19:08.640 --> 0:19:11.439 of dark matter. What would happen in that case. In 0:19:11.480 --> 0:19:14.919 that case, there'd be a much stronger gravitational force than 0:19:14.960 --> 0:19:17.360 you would expect from one Sun, and for the Earth 0:19:17.440 --> 0:19:18.800 to stay in its orbit, it would have to go 0:19:18.920 --> 0:19:22.520 much much faster, and so you would see a discrepancy. 0:19:22.560 --> 0:19:24.919 You'd measure the speed at which the Earth was orbiting 0:19:25.160 --> 0:19:28.040 the Sun, and you'd say, huh, it's going way too fast. 0:19:28.720 --> 0:19:32.240 What's what's um, what's keeping it together, what's keeping it 0:19:32.280 --> 0:19:34.320 in the Solar system? Why isn't it just flying off? 0:19:34.440 --> 0:19:36.280 And then you would deduce the presence of all those 0:19:36.359 --> 0:19:39.640 dark suns. Right, So this listener is like, well, can 0:19:39.720 --> 0:19:41.320 we see the dark matter? Because We've said on this 0:19:41.320 --> 0:19:43.679 podcast several times, a dark matter is everywhere. It's not 0:19:43.760 --> 0:19:45.720 just out there, it's here, It's in this room, it's 0:19:45.720 --> 0:19:47.320 on your planet, it's hanging out in that bunch of 0:19:47.359 --> 0:19:49.679 bananas you just ate. It's everywhere. So why can't we 0:19:49.680 --> 0:19:51.640 see it in our solar system? Right? Well, I guess 0:19:51.720 --> 0:19:54.160 question number one is is there dark matter in our 0:19:54.160 --> 0:19:56.960 solar system? And then question number two is is does 0:19:57.000 --> 0:20:00.840 it influence the orbit of planets? So that Daniels, is 0:20:00.840 --> 0:20:03.280 there a dark matter here in our solar system? We 0:20:03.359 --> 0:20:06.359 think so. Now we don't know for sure, and the 0:20:06.400 --> 0:20:08.800 reason is that gravity is pretty weak, right, as we 0:20:08.880 --> 0:20:11.639 talked about recently, and so it's hard to get a 0:20:11.680 --> 0:20:14.080 sense for exactly where dark matter is because the only 0:20:14.080 --> 0:20:16.040 way that we can see it is is through its 0:20:16.040 --> 0:20:18.600 gravitational effects, and so we can see its effects sort 0:20:18.600 --> 0:20:21.160 of like on a galaxy sized scale, but it's really 0:20:21.160 --> 0:20:23.119 hard to get a very clear map of where the 0:20:23.200 --> 0:20:26.560 dark matter is. But we think it probably is. We 0:20:26.600 --> 0:20:29.480 think it's probably distributed pretty evenly through the galaxy. There's 0:20:29.480 --> 0:20:31.639 a blob in the very center and it sort of 0:20:31.720 --> 0:20:35.200 just falls off gradually. So we suspect, like we would 0:20:35.200 --> 0:20:38.720 see it as a haze just permeating everything exactly. And 0:20:38.720 --> 0:20:40.720 you know what a deep question about dark matter is, 0:20:40.760 --> 0:20:43.359 like is it just a smooth haze or are there structures? 0:20:43.359 --> 0:20:45.480 It's a stuff happening. Is there like life forms in 0:20:45.560 --> 0:20:48.000 dark matter? We really don't know because we haven't been 0:20:48.000 --> 0:20:50.200 able to see it with enough resolution, because the only 0:20:50.200 --> 0:20:53.240 way we've ever been able to probe it is through gravity. 0:20:53.280 --> 0:20:56.040 And that's a it's you know, real frustration for us 0:20:56.080 --> 0:20:58.520 as scientists. It's like most of the matter in the 0:20:58.600 --> 0:21:01.560 universe is there, it's in front of us. We can't 0:21:01.600 --> 0:21:03.920 see it. We can't tell if it's doing anything interesting 0:21:04.040 --> 0:21:06.639 or just sort of a smooth haze. Right, And so 0:21:06.680 --> 0:21:08.359 the question is if we are kind of in a 0:21:08.440 --> 0:21:11.119