WEBVTT - Listener Questions 5 0:00:08.080 --> 0:00:12.240 Hey, Daniel, do you get tired of answering questions? Oh? Never, 0:00:12.560 --> 0:00:16.600 I love our listener questions. I just mean questions in general, 0:00:16.720 --> 0:00:20.680 like about the universe, about your personal life, poor like 0:00:20.760 --> 0:00:26.800 this question you're asking me now from your podcast host partner. No, 0:00:26.960 --> 0:00:28.960 people ask me questions all the time, but it's fun 0:00:28.960 --> 0:00:31.440 to answer them. You know, sometimes I wish I got 0:00:31.520 --> 0:00:34.800 asked more science questions, you know, sometimes with questions are 0:00:34.840 --> 0:00:37.680 more prosaic. But about your kids? And your kids constantly 0:00:37.760 --> 0:00:41.520 pester you with science questions too, I wish they asked more. 0:00:41.640 --> 0:00:43.960 You know. It's the occasional like what does the black 0:00:44.000 --> 0:00:46.239 hole look like? But more often it's like can I 0:00:46.280 --> 0:00:48.680 have more dessert? Or how could my sister just to 0:00:48.800 --> 0:00:52.680 use the iPad more than I do? And the answer 0:00:52.720 --> 0:00:56.120 is always the same. Nobody knows that we have no idea. 0:00:59.200 --> 0:01:02.120 They're kind of six questions too, aren't they? Like? Um, 0:01:02.440 --> 0:01:04.720 they're about time? Who gets more time on the iPad? 0:01:04.920 --> 0:01:10.240 Or matter who gets more desserted? Exactly? And what about you? 0:01:10.240 --> 0:01:13.520 Your kids ask you science questions? Uh? They do, yeah, 0:01:13.560 --> 0:01:16.920 pretty pretty often. I think my kids, um like to 0:01:16.959 --> 0:01:19.720 read and sometimes they kind of make connections in their 0:01:19.720 --> 0:01:22.720 head and they ask me questions. And what do you 0:01:22.760 --> 0:01:24.440 do when they ask you questions if you don't know 0:01:24.480 --> 0:01:26.840 the answer. What do you mean you assume that I 0:01:26.920 --> 0:01:29.959 don't know the answers. I often don't know the answer, 0:01:30.120 --> 0:01:33.160 so I assume not everybody has all the answers. Sure, no, 0:01:33.680 --> 0:01:39.160 Well I do my best. I guess um and maybe baby. Mainly, 0:01:39.200 --> 0:01:41.160 I just tell them to send their questions into our 0:01:41.160 --> 0:01:45.640 podcast so that you can answer them. That sounds good. 0:01:45.640 --> 0:01:47.800 I'm glad to be your backup science parent. I mean, 0:01:47.840 --> 0:01:50.120 what's the whole point of befriending as physicists if not 0:01:50.200 --> 0:01:53.320 to get these questions answered? I knew, just would you 0:01:53.360 --> 0:01:56.080 want to be friends with the physicists? I knew? I 0:01:56.120 --> 0:02:15.000 felt used. Now I know why. Hi am Jorge. I'm 0:02:15.040 --> 0:02:19.440 a cartoonist and the creator of PhD Comics. Hi I'm Daniel. 0:02:19.480 --> 0:02:23.359 I'm a particle physicist and a backup science parent for 0:02:23.480 --> 0:02:26.520 many people out there. And welcome to our podcast, Daniel 0:02:26.560 --> 0:02:30.079 and Jorge Explain the Universe, a production of I Heart 0:02:30.160 --> 0:02:33.959 Radio in which we take funny, weird, amazing, crazy things 0:02:34.000 --> 0:02:36.320 about the universe and explain them to you so that 0:02:36.360 --> 0:02:39.760 you can explain them to your kids or your parents 0:02:40.080 --> 0:02:43.160 or just sit them down with with our podcast as 0:02:43.280 --> 0:02:47.959 free babysitting. That's right. Yeah, so we we love answering questions, 0:02:48.040 --> 0:02:50.440 right Daniel. Oh yeah, it's really fun because we can 0:02:50.480 --> 0:02:52.440 think about the universe and we can talk about what's 0:02:52.440 --> 0:02:56.200 exciting for us. But the most is interesting is answering 0:02:56.280 --> 0:02:59.440 questions from listeners because it reveals what they understand and 0:02:59.480 --> 0:03:02.079 what they own't and what they're wondering about, what all 0:03:02.080 --> 0:03:05.520 those collective brains out there are cognating on. Yeah, so 0:03:05.680 --> 0:03:10.639 if you don't know this already, we actually answer people's questions. 0:03:11.160 --> 0:03:13.799 If we have an Instagram account, on Twitter account, on 0:03:13.840 --> 0:03:17.160 Facebook account, and if you post a question, well, first 0:03:17.160 --> 0:03:19.799 of all, follow us there, but if you post a question, 0:03:19.880 --> 0:03:23.680 most likely Daniel will answer the question, right Daniel, or 0:03:23.720 --> 0:03:27.160 at least maybe one of your regrets, that's right. No, 0:03:27.320 --> 0:03:30.120 I'll answer questions via email or Twitter or Facebook. I'll 0:03:30.160 --> 0:03:33.720 be honest, though, I don't use Instagram, so all those 0:03:33.760 --> 0:03:37.119 people asking physics questions on Instagram are just questioning into 0:03:37.160 --> 0:03:40.440 the void. Sorry, folks. The question is does anyone use 0:03:40.480 --> 0:03:46.280 Instagram anymore? Now that I don't, I think the question 0:03:46.400 --> 0:03:49.280 is who doesn't use Instagram these days? Just me, I guess, 0:03:50.680 --> 0:03:53.800 I guess just physicists, you know. But it's wonderful. We 0:03:53.880 --> 0:03:57.040 hear questions from all over the world, and sometimes there 0:03:57.040 --> 0:03:59.600 are questions people just had in their minds they wanted 0:03:59.640 --> 0:04:01.840 to know the answers to, and those are wonderful. But 0:04:01.960 --> 0:04:04.960 also sometimes the questions are in reaction to something we 0:04:05.000 --> 0:04:07.640 talked about on the show. You know, on the show, 0:04:07.680 --> 0:04:10.880 we do our best to think, what's confusing about this? 0:04:11.080 --> 0:04:13.400 How do we explain this? How do we make something clear? 0:04:13.720 --> 0:04:16.479 But we never can completely succeed. So it's really nice 0:04:16.520 --> 0:04:19.359 to have feedback when people say you said X, but 0:04:19.400 --> 0:04:22.520 then I that made me wonder why, and that helps 0:04:22.560 --> 0:04:24.560 us be more clear in the future. So please send 0:04:24.600 --> 0:04:28.359 us feedback, send us questions, send us presents, send us gags, 0:04:28.440 --> 0:04:32.080 send us whatever you have at Mostly you send us 0:04:32.160 --> 0:04:37.719 money please, I mean, how much do you think podcasting? Me? Podcaster? 0:04:38.279 --> 0:04:41.120 That's right? And sometimes people send us serious questions about 0:04:41.120 --> 0:04:44.479 the universe. And then sometimes people send us silly questions. Yeah, 0:04:44.520 --> 0:04:46.680 like what's been a silly question? All right, here's a 0:04:46.760 --> 0:04:49.799 question we got on Twitter from Patrick Nouman. He says, 0:04:50.640 --> 0:04:53.919 Dear Daniel and Jorge, I've got a question that really 0:04:54.000 --> 0:04:57.080 want to get answered. How heavy would a blob or 0:04:57.120 --> 0:05:00.800 banana bee of all of the photons in sun? And 0:05:00.920 --> 0:05:05.480 how big would it be? Oh? Interesting, So you took 0:05:05.600 --> 0:05:11.080 all the photons in the sun and somehow, what do 0:05:11.080 --> 0:05:14.560 you think, transformed them into a banana or put them 0:05:14.560 --> 0:05:17.560 in the space shaped them into a banana? What do 0:05:17.560 --> 0:05:20.599 you think I actually started trying to work on this question. 0:05:20.720 --> 0:05:23.440 At first, I thought, well, how many photons are in 0:05:23.480 --> 0:05:26.720 the sun, right, like, is that a number? Um? You know, 0:05:26.880 --> 0:05:29.480 and it's pretty tough. But it turns out you can 0:05:29.480 --> 0:05:32.839 do a rough calculation and the sun creates ten to 0:05:32.960 --> 0:05:40.600 the forty five photons per second. That's ten with that's 0:05:40.600 --> 0:05:44.040 a lot of photons, a lot of like trillion, billy 0:05:44.200 --> 0:05:50.200 busily but gillions, yes, exactly, billions and yeah, exactly. But 0:05:50.240 --> 0:05:52.279 not all those photons escape the sun. You know, the 0:05:52.320 --> 0:05:54.400 sun is a huge ball of plas and most of 0:05:54.400 --> 0:05:56.200 the stuff that's made by the Sun is then just 0:05:56.320 --> 0:05:59.320 reabsorbed by the Sun, and so only things that actually 0:05:59.400 --> 0:06:02.520 penetrate leave the Sun and hate your eyeballs arrive here 0:06:02.600 --> 0:06:05.120 on Earth. That's a tiny fraction what comes out of 0:06:05.160 --> 0:06:07.719 the Sun. But anyway, let's say you had ten to 0:06:07.800 --> 0:06:11.039 the forty five photons. Okay, that's a huge amount of 0:06:11.120 --> 0:06:14.480 energy um. And then this question is interesting. He said, 0:06:14.480 --> 0:06:17.400 how big would that be? Right? Like if you had 0:06:17.440 --> 0:06:20.960 a pile of tending the forty five photons, right? How well? 0:06:21.000 --> 0:06:25.120 How how how close together can you cram them in? Maybe? Yeah, 0:06:25.160 --> 0:06:28.320 And that's really interesting because there's no limit on how 0:06:28.320 --> 0:06:31.839 close you can cram photons together. That's not true ordinary 0:06:31.880 --> 0:06:36.160 matter like electrons and other particles. These things are fermions, 0:06:36.160 --> 0:06:38.919 and fermions are different from photons and other kind of 0:06:38.920 --> 0:06:42.880 particles that we call bosons because fermions have to have 0:06:43.080 --> 0:06:45.919 different quantum states. No two of them can be in 0:06:45.960 --> 0:06:49.000 the same quantum state. They can literally be on top 0:06:49.040 --> 0:06:51.400 of each other. That's impossible, that's right. They have to 0:06:51.440 --> 0:06:54.520 have some difference, like you can have two electrons in 0:06:54.600 --> 0:06:57.240 the same level of energy in a in an atom, 0:06:57.440 --> 0:06:59.760 but then they have different have to have different spins 0:06:59.839 --> 0:07:03.680 or something different about them, and so fer meons have 0:07:03.920 --> 0:07:07.720 to be distinguishable, whereas bosons, these are particles with integer 0:07:07.800 --> 0:07:10.120 spin like a photon. They can be right on top 0:07:10.160 --> 0:07:12.280 of each other. They can be exactly the same place, 0:07:12.320 --> 0:07:14.880 have the same momentum, had the same everything. I feel 0:07:14.880 --> 0:07:18.000 like the silly question is is gotten a little seriously Yeah, 0:07:18.960 --> 0:07:22.200 serious physics, yea, even silly questions reveals something interesting about 0:07:22.240 --> 0:07:25.040 the universe. And so you can have ten to the 0:07:25.040 --> 0:07:27.640 forty five photons on the head of a pin, basically 0:07:27.920 --> 0:07:30.880 right or on top of each other. You're saying, yes, exactly, 0:07:30.920 --> 0:07:33.600 all on top of each other in a tiny, tiny space. 0:07:33.800 --> 0:07:36.280 So thank you Patrick for sending in that hilarious question. 0:07:36.320 --> 0:07:38.160 It really made us think, and there really is some 0:07:38.240 --> 0:07:41.640 physics in that question, even in silly questions. Well, we 0:07:41.640 --> 0:07:45.240 do have three questions today from listeners, and so that 0:07:45.400 --> 0:07:48.360 is the topic of today's podcast. To be on the podcast, 0:07:48.440 --> 0:07:59.720 we'll be talking about listener questions five point five point 0:07:59.760 --> 0:08:02.760 one five point one because we because we just answered 0:08:02.800 --> 0:08:05.680 Patrick's questions, so we got to add a little that's right. 0:08:05.720 --> 0:08:09.320 We're part way through this episode already. Um, that's right. 0:08:09.320 --> 0:08:12.680 We'll be answering questions about electrons, about space, about stars, 0:08:12.720 --> 0:08:16.360 about black holes, questions from far away, and questions from 0:08:16.480 --> 0:08:19.800 surprisingly nearby. Yeah, and we might even know the answer 0:08:19.840 --> 0:08:23.000 to some of these questions this time, and if we don't, 0:08:23.040 --> 0:08:26.240 will speculate hilariously. All right, let's jump right into it. Daniel, there, 0:08:26.240 --> 0:08:29.680 Our first question today is from this really pretty cool guy, 0:08:30.120 --> 0:08:32.439 fun guy, one of maybe one of my favorite people, 0:08:32.440 --> 0:08:35.680 has a great dad. Yeah, so this is a question 0:08:35.760 --> 0:08:40.720 from Oliver from southern California. What if for whole solar 0:08:40.760 --> 0:08:44.800 system is in a black hole and we don't notice? Wow, 0:08:44.960 --> 0:08:48.160 that's a deep question. His voice sounds a little familiar 0:08:48.200 --> 0:08:51.000 to me. Yeah. What a what a smart sounding little kid. 0:08:51.600 --> 0:08:53.679 He sounds like he might grow up to be a cartoonist. 0:08:55.200 --> 0:08:58.559 Well not if he's that smart, hopefully. So yeah, that's 0:08:58.559 --> 0:09:01.440 my son who just asked that question in and he 0:09:01.559 --> 0:09:03.439 just turned to me one day, Well, what happened? What? 0:09:03.600 --> 0:09:06.280 He was reading our book? So we, Daniel and I 0:09:06.320 --> 0:09:08.280 wrote a book called We Have No Idea, A Guide 0:09:08.280 --> 0:09:11.080 to the Unknown Universe, available now in Amazon dot com. 0:09:11.120 --> 0:09:13.960 And and you can verify it's been read by at 0:09:14.000 --> 0:09:16.560 least one person since your son is reading it. That's right, 0:09:17.280 --> 0:09:19.320 that's right. He's under age, but he still counts as 0:09:19.320 --> 0:09:22.960 a person. He's nine years old, and so he's been 0:09:23.000 --> 0:09:25.240 reading our book and I always kind of wonder how 0:09:25.320 --> 0:09:27.760 much of it he's getting. You know, he's nine, he's 0:09:27.800 --> 0:09:31.120 in third grade. Um, but he seems to be enjoying it, 0:09:31.280 --> 0:09:32.920 and he keeps reading it, and so one day he 0:09:33.000 --> 0:09:35.800 just turned to me and he asked me this question, right, 0:09:35.880 --> 0:09:38.040 and what do you think is behind the question? What 0:09:38.080 --> 0:09:40.440 do you think he's wondering? Explain the question to me? 0:09:40.679 --> 0:09:44.559 Even explain my son do a deep dive. If I 0:09:44.640 --> 0:09:47.040 knew that answer, Daniel, if I could explain my son, 0:09:47.480 --> 0:09:50.599 my parenting experience would be so much. You know, I 0:09:50.640 --> 0:09:53.199 thought it was really interesting. One part of his question says, 0:09:53.600 --> 0:09:58.120 what if our whole solar system is in a black hole? Cool? Fascinating, Yeah, 0:09:58.200 --> 0:10:02.640 But then he says, and we don't don't even notice? 0:10:03.280 --> 0:10:06.640 Like I think that taps into you know, is the 0:10:06.720 --> 0:10:10.160 universe different from how we expected? Is it possible that 0:10:10.200 --> 0:10:12.400 we think we're living in universe X, but we're actually 0:10:12.440 --> 0:10:15.120 living in universe? Why? You know? I think he was 0:10:15.160 --> 0:10:19.280 probably kind of reading about black holes and he just 0:10:19.360 --> 0:10:22.680 kind of wondered, like, what what if? What if we're 0:10:22.679 --> 0:10:26.320 inside of a black hole? Is that possible? Like could 0:10:26.320 --> 0:10:30.720 the universe? Or or like could could a solar system 0:10:30.800 --> 0:10:35.200 exists inside of a black hole? And you know we 0:10:35.240 --> 0:10:38.080 don't even know it? Yeah, And I think there's something 0:10:38.120 --> 0:10:42.120 wonderful there about the feeling that maybe, you know, the 0:10:42.200 --> 0:10:44.360 universe could be revealed to be totally different from what 0:10:44.440 --> 0:10:47.760 you expected, because that's precisely happened a lot of times 0:10:47.760 --> 0:10:51.240 in history, right, we thought, oh, the universe works this way. Nope, 0:10:51.360 --> 0:10:53.960 it's totally different from what you imagined. And those are 0:10:54.000 --> 0:10:56.720 the best moments in physics. So to hear your son 0:10:56.840 --> 0:10:59.760 like sort of wondering if he's coming to that realization 0:10:59.840 --> 0:11:02.599 him self, or wondering if this kind of realization is 0:11:02.600 --> 0:11:05.120 around the corner, that's fantastic. He's been bitten by the 0:11:05.120 --> 0:11:08.200 physics bug, so be careful. Oh no, he's gonna be 0:11:08.440 --> 0:11:11.680 like Spider Man. Well that's only if he's bitten by 0:11:11.679 --> 0:11:16.280 a radioactive physicist. Okay, radioactive. Well I grew up in 0:11:16.320 --> 0:11:18.760 Los Alamos, so maybe I'm especially radioactive. But I'll do 0:11:18.800 --> 0:11:21.200 my best not to not to about your son. Yeah, 0:11:21.200 --> 0:11:24.719 but let's break it down. Um, it's interesting question. And 0:11:24.760 --> 0:11:27.080 you know, something that's important to think about is sort 0:11:27.080 --> 0:11:30.160 of the size of a black hole, like, could our 0:11:30.400 --> 0:11:34.680 entire solar system fit into a black hole? Well? Right, 0:11:34.720 --> 0:11:37.160 the size of a black hole is really we can 0:11:37.280 --> 0:11:39.440 usually consider that to be the size of the event 0:11:39.559 --> 0:11:42.839 horizon that's the point, right, the black style. Yeah, like 0:11:43.360 --> 0:11:46.360 the point return. Look at a black hole, it would 0:11:46.400 --> 0:11:49.240 look like a black sort of sphere, and so the 0:11:49.280 --> 0:11:52.160 size of that sphere, that's the size of the black yeah. Yeah, 0:11:52.240 --> 0:11:55.440 And if you go past that point, you can't escape, right. 0:11:55.520 --> 0:11:58.000 And nobody knows what's inside of a black hole, but 0:11:58.040 --> 0:12:00.520 we know how to calculate the size of the horizon. 0:12:00.559 --> 0:12:03.360 It's determined just by the amount of stuff in the 0:12:03.360 --> 0:12:05.920 black hole. So the more mass in the black hole, 0:12:06.160 --> 0:12:10.000 the stronger the gravitational pull. The farther away it can 0:12:10.080 --> 0:12:13.160 grab stuff and never let go, right, So the size 0:12:13.160 --> 0:12:15.880 of the black hole is determined by its mass. So 0:12:15.920 --> 0:12:18.880 how much stuff is in our solar system? Well, basically 0:12:18.960 --> 0:12:21.480 the first approximation our solar system is just a soun. 0:12:22.160 --> 0:12:25.560 Like the rest of the stuff in the solar system Jupiter, Mars, 0:12:25.880 --> 0:12:29.240 me you hamsters, all that stuff is negligible. It's a 0:12:29.240 --> 0:12:31.800 tiny fraction of the mass of the solar system. So 0:12:31.880 --> 0:12:34.720 basically you can ask, like, if you had a black 0:12:34.720 --> 0:12:38.120 hole with the mass of our Sun, how far away 0:12:38.160 --> 0:12:40.800 would the event horizon B would it be out past 0:12:40.920 --> 0:12:43.000 the edge of the black of the solar system? Is 0:12:43.040 --> 0:12:45.800 it possible to fit a solar system in a black 0:12:45.840 --> 0:12:48.560 hole that has the mass of our Sun. It's sort 0:12:48.559 --> 0:12:51.160 of the way I interpret the question. So you're interpreting 0:12:51.200 --> 0:12:56.120 the question as could our solar system be a black hole? Yeah? Exactly? 0:12:56.200 --> 0:12:58.720 Could we be inside a black hole right now? Is 0:12:58.720 --> 0:13:01.280 there enough room in a black hole with the mass 0:13:01.320 --> 0:13:05.240 of the Sun to fit the entire solar system? So 0:13:05.360 --> 0:13:08.400 could we be in a hole where the only thing 0:13:08.400 --> 0:13:11.800 inside of it is our solar system? Yeah? Exactly exactly 0:13:11.880 --> 0:13:13.719 is how you're interrupting the question. And the answer to 0:13:13.760 --> 0:13:17.800 that is no, Because a black hole that has only 0:13:17.840 --> 0:13:20.679 the mass of our sun, the event horizon would only 0:13:20.760 --> 0:13:24.240 be three kilometers from the center of the Sun, and 0:13:24.320 --> 0:13:27.040 so that definitely wouldn't be big enough to have the 0:13:27.080 --> 0:13:29.240 whole solar system in it, because the solar system is 0:13:29.280 --> 0:13:33.360 a lot more than three kilometers. It's one billion kilometers wide. 0:13:33.400 --> 0:13:35.000 So we couldn't be in a black hole where the 0:13:35.040 --> 0:13:38.480 only thing in it was our solar system. But is 0:13:38.520 --> 0:13:42.000 it possible that we are that our solar system is 0:13:42.120 --> 0:13:44.880 inside of somebody else's black hole? You know what I mean? Like, 0:13:45.880 --> 0:13:48.199 maybe there's a black hole out there with a lot 0:13:48.200 --> 0:13:51.439 of mass inside of it and we are just inside 0:13:51.440 --> 0:13:54.439 of the event horizon of that black hole floating around. Yeah, 0:13:54.520 --> 0:13:57.959 that's possible. Right, Let's let's consider that for a moment. So, 0:13:58.040 --> 0:14:01.960 what if there's a really ends blobs somewhere else sort 0:14:02.000 --> 0:14:05.120 of nearby, and that makes a black hole that's big 0:14:05.240 --> 0:14:08.440 enough to encompass us, and we're inside that black hole 0:14:08.640 --> 0:14:13.080 right right right, Well that's possible, but it's difficult to 0:14:13.120 --> 0:14:16.400 imagine because such a huge mass would have a big 0:14:16.440 --> 0:14:19.200 effect on us. You know, if there was a like 0:14:19.360 --> 0:14:21.960 if there's a really big mass somewhere else inside our 0:14:21.960 --> 0:14:25.000 Solar system next to the Sun, like an invisible huge 0:14:25.040 --> 0:14:28.240 blob of dark matter, that that made their enough mass 0:14:28.240 --> 0:14:30.440 so that the black hole was big enough, we would 0:14:30.480 --> 0:14:33.280 definitely notice that that would affect the orbit of the planets. 0:14:33.800 --> 0:14:35.800 What if there was another big mass kind of far 0:14:35.880 --> 0:14:39.000 away but close enough that we were still inside the 0:14:39.040 --> 0:14:43.120 event horizon, Well, you're talking about still really strong gravity. 0:14:43.400 --> 0:14:47.600 So it's hard to imagine having some enormously powerful gravitational 0:14:47.640 --> 0:14:51.320 attractor nearby and not having it disturbed like the orbits 0:14:51.360 --> 0:14:54.560 of the planets or even just tossing of baseballs and 0:14:54.560 --> 0:14:56.880 all sorts of stuff. So I think if you were 0:14:56.880 --> 0:14:59.640 inside a black hole that was big enough to hold 0:14:59.640 --> 0:15:02.160 a solar system, it would have to have a huge mass, 0:15:02.520 --> 0:15:05.360 and that mass would definitely be noticeable. It would affect 0:15:05.400 --> 0:15:07.480 the way things move on Earth, would it, though, Because 0:15:07.520 --> 0:15:10.920 you know, like um so so our our solar system 0:15:11.200 --> 0:15:14.040 is moving around a galaxy, right, Like, a galaxy has 0:15:14.040 --> 0:15:17.760 a lot of mass and um and it's huge, and 0:15:17.840 --> 0:15:19.400 there's a lot there's a huge black hole in the 0:15:19.440 --> 0:15:22.920 center of the galaxy, but it's not really affecting us 0:15:23.440 --> 0:15:27.240 in a local level, right, Like that gravity is kind 0:15:27.280 --> 0:15:30.160 of spinning us around the galaxy, but it's not really 0:15:30.400 --> 0:15:33.600 changing the orbits of the planets around the Sun, that's right. Yeah, 0:15:33.640 --> 0:15:35.400 And that black hole in the center of the galaxy 0:15:35.640 --> 0:15:38.560 is really massive and it's pretty big, but it's also 0:15:38.680 --> 0:15:42.480 super duper duper duper far away. Right. Any black hole 0:15:42.480 --> 0:15:45.800 that's either near enough to include us or far away 0:15:45.840 --> 0:15:49.760 but huge enough to include us still would definitely affect 0:15:49.880 --> 0:15:52.479 the gravitational poll But you know, I haven't done the calculation. 0:15:53.080 --> 0:15:57.240 There is one configuration I imagine though. Imagine our entire 0:15:57.280 --> 0:16:01.800 solar system and then it's surrounded by some enormously dense 0:16:01.840 --> 0:16:06.520 sphere of material. Okay, if you're inside a sphere of material, 0:16:06.800 --> 0:16:09.760 then the gravitational pull of that stuff doesn't affect you 0:16:09.840 --> 0:16:13.000 at all, right, because it all balances out. Is enough 0:16:13.040 --> 0:16:15.520 stuff on the left to balance the stuff on the right. 0:16:16.000 --> 0:16:17.840 Just like that episode we talked about where you jump 0:16:17.920 --> 0:16:20.480 inside the Earth. Once you get to the center of 0:16:20.480 --> 0:16:24.920 the Earth, is no gravitational force from the stuff around you. Right, Well, 0:16:25.040 --> 0:16:28.160 if you have to spear a super dense material surrounding 0:16:28.200 --> 0:16:32.360 the Solar System, right, then that might be enough to 0:16:32.400 --> 0:16:35.600 create a black hole, right that we would be inside of. 0:16:36.000 --> 0:16:39.080 We wouldn't feel the gravitational force because we would be 0:16:39.200 --> 0:16:42.400 inside all the stuff. It would be all around us. Yeah, 0:16:42.560 --> 0:16:44.640 that's what I mean. Yeah, yeah, but they have to 0:16:44.680 --> 0:16:48.520 be perfectly distributed, right. And the only reason that there's 0:16:48.600 --> 0:16:51.400 one reason to think that's not the case, and that's 0:16:51.440 --> 0:16:54.080 that we have sent stuff outside the Solar System, Like 0:16:54.160 --> 0:16:57.240 we launched probes and they're floating off into space and 0:16:57.280 --> 0:17:00.040 we're watching them and they haven't like banged up and 0:17:00.280 --> 0:17:03.600 the wall of some hugely massive blob of stuff. But 0:17:03.640 --> 0:17:06.560 what have you expand that idea even further to encompass 0:17:06.760 --> 0:17:11.520 the whole observable universe. It is possible then that we 0:17:11.600 --> 0:17:14.400 could be inside of a black hole. Yeah, yeah, it's 0:17:14.440 --> 0:17:18.640 possible the entire observable universe is inside a black hole. Yes, 0:17:19.760 --> 0:17:21.520 you can't rule that out. How do you feel about 0:17:21.520 --> 0:17:25.080 saying that on a public record, Um, I wonder if 0:17:25.080 --> 0:17:29.080 any of my colleagues are listening. No, I think it's awesome. 0:17:29.400 --> 0:17:32.080 You would be surprised. I think it's awesome, And I 0:17:32.119 --> 0:17:35.359 think sometimes these awesome questions come from the minds of children, 0:17:35.400 --> 0:17:38.040 And that's why I hope that people are listening to 0:17:38.040 --> 0:17:41.040 the podcast with their kids, because kids ask amazing questions 0:17:41.200 --> 0:17:43.119 that make us think about things we otherwise would have 0:17:43.119 --> 0:17:47.320 totally discarded that might actually be reality. Well, so that's 0:17:47.320 --> 0:17:49.320 so that's the answer. The answer is that it is 0:17:49.359 --> 0:17:52.160 totally possible that we are inside of a black hole 0:17:52.240 --> 0:17:54.639 and not knowing. Yeah, but I think our whole universe 0:17:54.640 --> 0:17:56.239 would have to be inside the black hole, not just 0:17:56.280 --> 0:17:58.760 the solar system. But yeah, that's a pretty small conviat 0:17:58.800 --> 0:18:00.920 for it for a yes answer to that question, isn't 0:18:00.920 --> 0:18:03.280 that sort of a theory out there that were like 0:18:03.359 --> 0:18:06.399 the whole universe are are inside the whole universe inside 0:18:06.440 --> 0:18:08.280 of a black hole, and there are other black holes 0:18:08.320 --> 0:18:10.720 and stuff. Like that or is that pretty fringe? I 0:18:10.720 --> 0:18:13.080 think it is the theory out there, and it's pretty fringe, 0:18:13.119 --> 0:18:16.760 But it's also totally possible, you know, like we really 0:18:16.800 --> 0:18:19.119 just we don't know what's going on inside black holes? 0:18:19.160 --> 0:18:22.080 Are there little universes in there? You know? The inside 0:18:22.080 --> 0:18:26.000 of a black hole is totally disconnected from the space 0:18:26.000 --> 0:18:27.920 that we live in, right, Like there's no way to 0:18:28.000 --> 0:18:30.919 get from here to there, right, That's why that's how 0:18:30.960 --> 0:18:33.240 a black hole works, even like can't escape it, not 0:18:33.320 --> 0:18:35.520 because it's like slowing down the light as it tries 0:18:35.560 --> 0:18:38.119 to leave, but because it's bent space in such a 0:18:38.160 --> 0:18:40.760 way that there's just no path out, like just zooming 0:18:40.760 --> 0:18:43.639 around inside the black hole. So in some ways you 0:18:43.640 --> 0:18:45.119 can think of it as sort of like a different 0:18:45.240 --> 0:18:49.080 universe disconnected from our our space, and so you can 0:18:49.119 --> 0:18:51.600 imagine then anything that goes on in there. And uh, 0:18:52.000 --> 0:18:56.399 when experiments can't constrain things, theorists minds tend to go wild, 0:18:56.560 --> 0:18:58.639 and so they think about all sorts of crazy stuff 0:18:58.680 --> 0:19:01.879 that could be inside there, insing bears or entire universes. 0:19:02.240 --> 0:19:05.440 Crazy scientists and nine year old boys whom I grew 0:19:05.520 --> 0:19:08.159 up to be crazy scientists. All right, Well, that's the 0:19:08.200 --> 0:19:12.240 answered for Oliver's son of Jorge, and I'll let him 0:19:12.240 --> 0:19:17.440 know if he has a good sum he stumped the physicists. Yeah, 0:19:17.480 --> 0:19:20.200 it's a great question. If he was Icelandic, his last 0:19:20.240 --> 0:19:26.439 name would be or Hasten exactly. All right, Well, we 0:19:26.520 --> 0:19:28.960 have two other awesome questions that we are going to 0:19:29.000 --> 0:19:33.640 answer about electron identity. I guess is that is that 0:19:33.920 --> 0:19:36.520 we would be the right topic and also about dark 0:19:36.600 --> 0:19:42.200 Matter stars, which sounds like a heavy battle band last 0:19:42.320 --> 0:19:45.200 science fiction movie. So stay tuned, will be right back. 0:19:58.080 --> 0:20:01.000 Al Right, we are back answering list are questions, and 0:20:01.080 --> 0:20:04.679 so our next question comes from Yugi from the Netherlands, 0:20:04.920 --> 0:20:10.520 and he is wondering if electrons have identity crises. That's right, 0:20:10.640 --> 0:20:13.240 And this particular listener is something of a super fan, 0:20:13.440 --> 0:20:16.639 writing to us on Twitter fairly often with insightful questions, 0:20:16.760 --> 0:20:18.320 and he sent me this one and I thought, well 0:20:18.400 --> 0:20:22.360 that's a good question, let's take it online, and so 0:20:22.520 --> 0:20:25.760 here he is, Hi, Danielle and Jorge. My name is 0:20:25.800 --> 0:20:29.960 Eugene Raudemake and I live in the Netherlands, hence the actions. 0:20:30.720 --> 0:20:33.240 I'm a big fan of your morphous poticast cities, for 0:20:33.400 --> 0:20:36.920 it makes me understand more of physics, and it makes 0:20:36.960 --> 0:20:41.439 me think a lot about the universe in general. After 0:20:41.480 --> 0:20:45.399 listening to your episode about quantum tunneling, the following question 0:20:45.440 --> 0:20:50.080 came to my mind. If an electron tapt well say A, 0:20:50.560 --> 0:20:54.640 suddenly appears in well B, how can physically still it's 0:20:54.680 --> 0:20:59.400 actually this very same electron. I realized that I had 0:20:59.600 --> 0:21:02.679 the both bowl empty swimming pool and the analogy in 0:21:02.760 --> 0:21:06.520 my mind when the Christians sue appearance in my will. 0:21:07.359 --> 0:21:12.080 Thanks for spending time answering my questions, all right, thank 0:21:12.080 --> 0:21:14.760 you for saying this question, and also for being a 0:21:14.800 --> 0:21:18.600 fan of the show. We really appreciate everyone listening out there. Yeah, exactly, 0:21:19.240 --> 0:21:21.919 And uh, it's really a wonderful question, you know. To me, 0:21:21.960 --> 0:21:24.760 it goes to the heart of like what are these particles? 0:21:24.760 --> 0:21:27.919 What are we talking about? Um? But the way I 0:21:27.960 --> 0:21:30.920 interpret his question is like, you haven't quite an electron 0:21:31.000 --> 0:21:34.000 over here, and physics tells us the electron can then 0:21:34.080 --> 0:21:36.679 later be over there. But his question is, how do 0:21:36.760 --> 0:21:40.360 you know it's the same electron? Right, because we don't 0:21:40.359 --> 0:21:43.040 have this sort of notion anymore of a classical path 0:21:43.080 --> 0:21:45.240 that you can like watch a baseball fly through the 0:21:45.280 --> 0:21:48.200 air and when a baseball, you know, when somebody hits 0:21:48.400 --> 0:21:50.919 a home run, you watch it fly. You don't ask like, 0:21:51.080 --> 0:21:53.520 is that the same baseball or is it suddenly swapped out? 0:21:54.080 --> 0:21:57.320 But with quantum mechanical particles, because you can't observe them 0:21:57.359 --> 0:22:00.000 all the way along the path, you just get these snapshots. 0:22:00.240 --> 0:22:02.000 You can sort of wonder like, how do you know 0:22:02.080 --> 0:22:04.800 that's the same electron? Maybe it's from another electron down 0:22:04.840 --> 0:22:06.920 the street, right, it's just Tom or Harry or Mary 0:22:07.000 --> 0:22:09.800 or Sally. I feel like the question is there such 0:22:09.840 --> 0:22:13.240 a thing as an electron? Is there an electron? You 0:22:13.240 --> 0:22:16.280 can say and follow it around and it has a 0:22:16.440 --> 0:22:19.800 birth in a you know, journey, and then it maybe 0:22:19.840 --> 0:22:22.719 answer at some point we can you follow an electron? 0:22:22.800 --> 0:22:25.760