1 00:00:08,520 --> 00:00:10,719 Speaker 1: Hey, Jorge, did you pack a bag? Why do I 2 00:00:10,800 --> 00:00:12,960 Speaker 1: need to back one? We're going on a field trip today. 3 00:00:13,119 --> 00:00:16,360 Speaker 1: Oh nice, Where are we going? We're going on a 4 00:00:16,520 --> 00:00:18,880 Speaker 1: physics field trip. Actually, does I mean I have to 5 00:00:19,480 --> 00:00:21,360 Speaker 1: go to a classroom or something. It means it's a 6 00:00:21,360 --> 00:00:24,560 Speaker 1: thought field trip, sort of like a thought experiment. I 7 00:00:24,680 --> 00:00:27,960 Speaker 1: don't need to bring snacks. It's a thought experiment, So 8 00:00:28,000 --> 00:00:30,560 Speaker 1: you can bring any snacks you can think of. Well, 9 00:00:30,760 --> 00:00:48,159 Speaker 1: I can think of a lot of snacks. I am 10 00:00:48,240 --> 00:00:52,200 Speaker 1: or handmade cartoonists and the creator of PhD comics. I'm Daniel. 11 00:00:52,280 --> 00:00:55,360 Speaker 1: I'm a particle of physicist and I enjoy snacks from 12 00:00:55,400 --> 00:00:58,120 Speaker 1: around the world. Do you just think you're a physicist, Daniel, 13 00:00:58,200 --> 00:01:02,720 Speaker 1: or are you an actual physicist? What's the difference? Welcome 14 00:01:02,760 --> 00:01:06,720 Speaker 1: to our philosophy podcast, folks, the philosophy of being a physicist. 15 00:01:06,800 --> 00:01:10,360 Speaker 1: That's another branch of philosophy we invented on this podcast. 16 00:01:10,800 --> 00:01:13,840 Speaker 1: Now is it a branch of philosophy or physics. It's 17 00:01:13,840 --> 00:01:17,240 Speaker 1: a whole new field all into itself. No. On this podcast, 18 00:01:17,280 --> 00:01:19,640 Speaker 1: we'd like to think that anybody who asked questions about 19 00:01:19,640 --> 00:01:22,399 Speaker 1: the universe is a physicist. So anyone who claims to 20 00:01:22,400 --> 00:01:25,039 Speaker 1: be a physicist is a physicist in my book, Well, 21 00:01:25,040 --> 00:01:27,760 Speaker 1: welcome to our podcast Daniel and Jorge Explain the Universe, 22 00:01:27,800 --> 00:01:30,319 Speaker 1: a production of I Heart Radio in which we all 23 00:01:30,360 --> 00:01:33,880 Speaker 1: act like physicists and ask deep questions about the universe. 24 00:01:34,000 --> 00:01:36,080 Speaker 1: How does it work, what does it look like? What 25 00:01:36,120 --> 00:01:38,600 Speaker 1: are those little bits over there? How did these things 26 00:01:38,680 --> 00:01:41,679 Speaker 1: even happen? And we ask those questions and try to 27 00:01:41,760 --> 00:01:44,720 Speaker 1: find the answers. Sometimes we get some answers, Sometimes we 28 00:01:44,800 --> 00:01:47,080 Speaker 1: just find more questions. But we hope to entertain you 29 00:01:47,120 --> 00:01:49,320 Speaker 1: a little bit along the way because there are a 30 00:01:49,320 --> 00:01:51,560 Speaker 1: lot of questions out there in the universe, because there 31 00:01:51,600 --> 00:01:55,160 Speaker 1: are a lot of mystery still out there unresolved in 32 00:01:55,160 --> 00:01:57,200 Speaker 1: the cosmos. That's right, because there are a lot of 33 00:01:57,280 --> 00:02:01,080 Speaker 1: people out there asking questions. Remember that questions don't belong 34 00:02:01,120 --> 00:02:03,400 Speaker 1: to the universe. They belong to us. There are our 35 00:02:03,560 --> 00:02:06,520 Speaker 1: personal questions about the universe. And the way that science 36 00:02:06,560 --> 00:02:10,720 Speaker 1: moves forward is people asking those questions, people thinking how 37 00:02:10,720 --> 00:02:13,560 Speaker 1: does that work? Or what does it look like in there? 38 00:02:13,960 --> 00:02:16,880 Speaker 1: Let's go find out. So the way we unravel secrets 39 00:02:16,880 --> 00:02:19,799 Speaker 1: to the universe is first by asking those big questions. Yeah, 40 00:02:19,840 --> 00:02:21,760 Speaker 1: I guess you're right. That is interesting to think about 41 00:02:21,880 --> 00:02:25,400 Speaker 1: that there are like the universe doesn't have mysteries on 42 00:02:25,440 --> 00:02:28,480 Speaker 1: its own. Like, I mean, the universe knows everything it 43 00:02:28,520 --> 00:02:30,880 Speaker 1: knows about itself. It's just us who don't know it. 44 00:02:31,000 --> 00:02:33,519 Speaker 1: And so we're asking questions and we make it a mystery. 45 00:02:33,840 --> 00:02:36,120 Speaker 1: That's right, except that we are part of the universe. 46 00:02:36,120 --> 00:02:38,399 Speaker 1: So maybe we are that part of the universe that's 47 00:02:38,440 --> 00:02:42,840 Speaker 1: asking itself questions about itself. Universe know thyself. Man, you 48 00:02:42,880 --> 00:02:46,600 Speaker 1: just give me a headache, a philosophical headache of physics tache. 49 00:02:47,639 --> 00:02:50,200 Speaker 1: But yeah, there are a lot of mysteries out there, 50 00:02:50,240 --> 00:02:53,760 Speaker 1: are a lot of pockets of unknown in the universe 51 00:02:53,800 --> 00:02:55,919 Speaker 1: that humans we just don't know what's inside of him, 52 00:02:55,960 --> 00:02:58,720 Speaker 1: that's right. And we are a curious species. We want 53 00:02:58,720 --> 00:03:01,639 Speaker 1: to see what's under that what's over that hill, what's 54 00:03:01,680 --> 00:03:04,720 Speaker 1: in that weird bag over there. We just want to know. 55 00:03:05,200 --> 00:03:06,920 Speaker 1: So we want to see all the cool stuff in 56 00:03:06,919 --> 00:03:09,280 Speaker 1: the universe. We use our telescopes to zoom in on 57 00:03:09,400 --> 00:03:12,640 Speaker 1: far away stuff. We pick up rocks that fell from space. 58 00:03:12,800 --> 00:03:15,200 Speaker 1: We want to see it all. Yeah, and there is 59 00:03:15,360 --> 00:03:21,280 Speaker 1: no more mysterious pocket of mystery, mysterious pocket of mystery 60 00:03:21,800 --> 00:03:25,840 Speaker 1: in the universe than a black hole. Black Holes are these, 61 00:03:25,919 --> 00:03:29,840 Speaker 1: you know, pockets of space time that nobody really knows 62 00:03:29,919 --> 00:03:31,920 Speaker 1: what's inside of them, And there might not be anything 63 00:03:32,040 --> 00:03:34,560 Speaker 1: interesting inside of them, but just the fact that nobody 64 00:03:34,600 --> 00:03:37,280 Speaker 1: can look inside, that nobody can go inside and tell 65 00:03:37,360 --> 00:03:40,280 Speaker 1: us what comes out, makes it mysterious. It's like if 66 00:03:40,280 --> 00:03:42,680 Speaker 1: I hold an empty pillow case in front of kids 67 00:03:42,680 --> 00:03:45,120 Speaker 1: and say what do you think's inside? They get excited. 68 00:03:45,760 --> 00:03:47,960 Speaker 1: Maybe this is a dinosaur were in there. It doesn't 69 00:03:47,960 --> 00:03:51,320 Speaker 1: really matter as long as it's hidden. It's mysterious and 70 00:03:51,320 --> 00:03:53,800 Speaker 1: what makes us curious. It sounds like something someone might 71 00:03:53,840 --> 00:03:56,520 Speaker 1: call the cops on you, Daniel, if you started doing 72 00:03:56,520 --> 00:03:59,680 Speaker 1: that random kids on the street. That was another thought experiment, 73 00:03:59,720 --> 00:04:05,160 Speaker 1: not recommended that in your thought arrest. Yeah, so black 74 00:04:05,160 --> 00:04:08,880 Speaker 1: holes are super weird. I mean they were theoretical up 75 00:04:08,960 --> 00:04:12,000 Speaker 1: until a little while ago, until we first saw one 76 00:04:12,320 --> 00:04:15,760 Speaker 1: with our own eyes, our own in tennis and cameras. 77 00:04:15,880 --> 00:04:18,240 Speaker 1: I mean that we saw them gravitationally, but nobody had 78 00:04:18,279 --> 00:04:21,039 Speaker 1: really sort of seen one until recently. That's right. There 79 00:04:21,080 --> 00:04:25,560 Speaker 1: were a theoretical curiosity because general relativity predicted that they existed, 80 00:04:25,720 --> 00:04:28,560 Speaker 1: but also predicted that they had something really really weird. 81 00:04:28,720 --> 00:04:31,480 Speaker 1: At their hearts, a singularity, a place where the theory 82 00:04:31,800 --> 00:04:36,080 Speaker 1: actually broke down because it predicted that space curvature went infinite. 83 00:04:36,360 --> 00:04:39,000 Speaker 1: So for a long time physicist thought, well, that probably 84 00:04:39,040 --> 00:04:42,479 Speaker 1: doesn't actually happen. The universe does something, there's something to 85 00:04:42,640 --> 00:04:46,400 Speaker 1: prevent that from really existing in reality. But then we 86 00:04:46,480 --> 00:04:49,520 Speaker 1: saw them. We see them at the center of our galaxy, 87 00:04:49,560 --> 00:04:52,680 Speaker 1: these super massive black holes with stars whizzing around them, 88 00:04:52,880 --> 00:04:56,120 Speaker 1: and we see stars that have collapsed into black holes. 89 00:04:56,160 --> 00:04:58,880 Speaker 1: So we know they are a real thing in the universe. 90 00:04:58,920 --> 00:05:01,200 Speaker 1: We just don't know it's in them. Yeah, well we 91 00:05:01,279 --> 00:05:03,919 Speaker 1: got a picture of them. They do indeed look like 92 00:05:03,960 --> 00:05:06,400 Speaker 1: black holes. I mean the picture that we got was 93 00:05:06,400 --> 00:05:08,200 Speaker 1: it last year, I think, or a couple of years ago. 94 00:05:08,760 --> 00:05:11,760 Speaker 1: It shows you a black circle basically with all the 95 00:05:12,000 --> 00:05:15,800 Speaker 1: right stuff scrolling around it, but it is indeed black 96 00:05:15,960 --> 00:05:18,600 Speaker 1: like there you can't see anything in the middle of it. Yeah, 97 00:05:18,640 --> 00:05:23,080 Speaker 1: it's simultaneously like amazing technologically and also kind of disappointing 98 00:05:23,520 --> 00:05:26,479 Speaker 1: because all you're really seeing is a sort of doughnut 99 00:05:26,600 --> 00:05:29,680 Speaker 1: of accretion disc around the black hole that's glowing in 100 00:05:29,800 --> 00:05:32,320 Speaker 1: just the way you'd expect, But the black hole itself 101 00:05:32,480 --> 00:05:34,599 Speaker 1: just looks black, and so it's sort of hard to 102 00:05:34,680 --> 00:05:37,760 Speaker 1: distinguish a black hole from nothing. Well, you can't see 103 00:05:37,760 --> 00:05:41,359 Speaker 1: any stars behind it, like in we look anywhere else 104 00:05:41,400 --> 00:05:45,039 Speaker 1: in space, you would see its stars behind him, right, Yeah, 105 00:05:45,080 --> 00:05:48,280 Speaker 1: that's true. And next to that really bright region from 106 00:05:48,279 --> 00:05:51,480 Speaker 1: the accretion disc, it is a pretty black shadow. So yeah, 107 00:05:51,560 --> 00:05:54,680 Speaker 1: you're seeing a very dark shadow from the black hole. Yeah. 108 00:05:54,800 --> 00:05:58,640 Speaker 1: So the question is what's inside of that dark region? 109 00:05:58,960 --> 00:06:01,000 Speaker 1: What's going on in there? Because you can't see in 110 00:06:01,080 --> 00:06:03,000 Speaker 1: it and there's nothing to see when you take a 111 00:06:03,000 --> 00:06:05,280 Speaker 1: picture of it. Yeah, and so the explorer and us 112 00:06:05,320 --> 00:06:08,680 Speaker 1: wonders what's in there? Is it possible to like send 113 00:06:08,720 --> 00:06:10,960 Speaker 1: a probe or a ship or even a person to 114 00:06:11,040 --> 00:06:13,320 Speaker 1: go explore? Yeah, and this is a situation that a 115 00:06:13,320 --> 00:06:15,719 Speaker 1: lot of people have considered, like what would it be 116 00:06:15,800 --> 00:06:19,279 Speaker 1: like to send something into the black hole? So today 117 00:06:19,320 --> 00:06:26,359 Speaker 1: on the podcast, we'll be asking the question, what's it 118 00:06:26,480 --> 00:06:30,360 Speaker 1: like to fall into a black hole? Is this something 119 00:06:30,400 --> 00:06:32,640 Speaker 1: you would wondered about? Horrid these days that have other 120 00:06:32,680 --> 00:06:38,719 Speaker 1: things to wonder about the faith of humanity without a 121 00:06:38,720 --> 00:06:40,520 Speaker 1: black hole. It makes me wonder like if I was 122 00:06:40,560 --> 00:06:42,600 Speaker 1: standing at the edge of a black hole, would I 123 00:06:42,680 --> 00:06:45,400 Speaker 1: be tempted to jump in because you might learn some 124 00:06:45,480 --> 00:06:47,800 Speaker 1: of the secrets of the universe. But on the other hand, 125 00:06:47,839 --> 00:06:50,240 Speaker 1: you'd probably die and at the very least would never 126 00:06:50,240 --> 00:06:52,159 Speaker 1: come back to see your family. So that'd be a 127 00:06:52,200 --> 00:06:53,800 Speaker 1: tough choice to have to make. Yeah, I think I 128 00:06:53,800 --> 00:06:56,719 Speaker 1: would wonder what it's like to jump into it, but 129 00:06:56,920 --> 00:06:59,320 Speaker 1: maybe not me jumping into it, you know what I mean? 130 00:06:59,400 --> 00:07:02,880 Speaker 1: Like I would love for I don't know somebody else 131 00:07:02,880 --> 00:07:05,839 Speaker 1: to do it, And for example, you'd happily send me 132 00:07:05,880 --> 00:07:08,600 Speaker 1: into a black hole if I could report back what 133 00:07:08,800 --> 00:07:10,960 Speaker 1: I mean, if you're standing at the edge of a 134 00:07:10,960 --> 00:07:17,200 Speaker 1: black hole, would I push you? Maybe don't answer that question. Well, 135 00:07:17,280 --> 00:07:19,720 Speaker 1: the good thing is the evidence would be totally gone. 136 00:07:20,480 --> 00:07:22,640 Speaker 1: They could never ask you if I pushed you or not. 137 00:07:22,760 --> 00:07:25,400 Speaker 1: The perfect crime. Wow, somebody has to write that science 138 00:07:25,400 --> 00:07:28,640 Speaker 1: fiction novel death by black hole black hole murder. Yeah, 139 00:07:28,720 --> 00:07:31,480 Speaker 1: the perfect crime because it technically it might not never happen. 140 00:07:32,280 --> 00:07:36,640 Speaker 1: It might even destroy the information. Wow. Well that's that. 141 00:07:36,760 --> 00:07:39,080 Speaker 1: The other next sci fi novels are criminals who use 142 00:07:39,120 --> 00:07:42,440 Speaker 1: black holes to erase their evidence. Yeah. So, as usually, 143 00:07:42,440 --> 00:07:45,120 Speaker 1: we were wondering how many people out there had asked 144 00:07:45,160 --> 00:07:48,360 Speaker 1: themselves this question, and how many people out there. I 145 00:07:48,440 --> 00:07:50,400 Speaker 1: think they have an answer for this. So, as usual, 146 00:07:50,480 --> 00:07:52,800 Speaker 1: Daniel went out into the wild of the Internet to 147 00:07:52,920 --> 00:07:56,960 Speaker 1: ask listeners what they think it's like to fall into 148 00:07:57,040 --> 00:07:59,320 Speaker 1: a black hole. And all of these folks answered this 149 00:07:59,440 --> 00:08:02,840 Speaker 1: question with knowing it in advance and no googling allowed. 150 00:08:03,080 --> 00:08:06,320 Speaker 1: If you would like the answer that questions for future episodes, 151 00:08:06,400 --> 00:08:09,280 Speaker 1: please write to us do questions at Daniel and Jorge 152 00:08:09,360 --> 00:08:12,760 Speaker 1: dot com. We will happily put your uninformed speculation on 153 00:08:12,800 --> 00:08:14,720 Speaker 1: the podcast. So I think about it for a second, 154 00:08:15,040 --> 00:08:17,160 Speaker 1: what do you think it would be like to fall 155 00:08:17,240 --> 00:08:20,400 Speaker 1: into a black hole. Here's what people had to say. 156 00:08:20,600 --> 00:08:25,040 Speaker 1: Either you fall in a really huge, immense black hole, 157 00:08:25,840 --> 00:08:30,320 Speaker 1: uh those super massive black holes, and you fall really 158 00:08:30,360 --> 00:08:34,720 Speaker 1: slowly and then died at some point, or you get 159 00:08:34,760 --> 00:08:39,160 Speaker 1: spaghettified in one of these smaller ones. I know that 160 00:08:39,200 --> 00:08:42,120 Speaker 1: as you fall into a black hole, you will be 161 00:08:42,240 --> 00:08:45,760 Speaker 1: experiencing everything in your own real time, so it's not 162 00:08:45,800 --> 00:08:48,199 Speaker 1: like everything will stop or anything like that for you. 163 00:08:48,440 --> 00:08:50,440 Speaker 1: As far as the rest, I would say, very painful, 164 00:08:51,000 --> 00:08:55,720 Speaker 1: thank you, be very good. I think it depends on 165 00:08:55,800 --> 00:08:58,480 Speaker 1: what you mean. So, like the body itself would be 166 00:08:58,559 --> 00:09:04,160 Speaker 1: what they're called spaghettifier and broken into its constituent atomic particles, 167 00:09:04,600 --> 00:09:07,240 Speaker 1: so you'd be pretty much ripped apart. But like the 168 00:09:07,280 --> 00:09:10,520 Speaker 1: gravity is so strong, but like even the difference in 169 00:09:10,559 --> 00:09:16,440 Speaker 1: your height would see a pretty significant shift in gravitational forces, 170 00:09:16,640 --> 00:09:19,840 Speaker 1: So the gravity on your feet would be very much stronger, 171 00:09:19,880 --> 00:09:22,920 Speaker 1: depending on restruction you're following in than the gravity you 172 00:09:22,920 --> 00:09:24,880 Speaker 1: know you'd feel. And at the top of your head, well, 173 00:09:24,880 --> 00:09:27,480 Speaker 1: I know that from the outside you'd never seen fallen 174 00:09:27,640 --> 00:09:32,400 Speaker 1: because time would slow down so much that they love frozen. 175 00:09:32,480 --> 00:09:37,880 Speaker 1: But you yourself, I think you'd probably be torn to shreds. 176 00:09:37,960 --> 00:09:42,600 Speaker 1: As you know, any part of you that was ahead 177 00:09:42,640 --> 00:09:44,719 Speaker 1: of some other part of you would be sucked in 178 00:09:45,240 --> 00:09:49,080 Speaker 1: much faster. And I guess we don't really know the answer, 179 00:09:49,120 --> 00:09:50,760 Speaker 1: but I assume it would be like torn to shreds. 180 00:09:51,080 --> 00:09:55,400 Speaker 1: I don't know. I think from what I know you 181 00:09:55,720 --> 00:09:59,199 Speaker 1: my body would be ripped apart. It would just be 182 00:10:00,000 --> 00:10:05,360 Speaker 1: and him, you know, stretched like a spaghetti uh, stretchy, 183 00:10:05,679 --> 00:10:09,760 Speaker 1: like one second you're there and the next ye're not. Obviously, 184 00:10:09,880 --> 00:10:12,120 Speaker 1: no one knows what it's actually like to fall into 185 00:10:12,160 --> 00:10:16,000 Speaker 1: a black hole, but from what I've read, the theory 186 00:10:16,160 --> 00:10:19,840 Speaker 1: is that you would be spaghettified because you know, if 187 00:10:19,880 --> 00:10:22,240 Speaker 1: you fell in the feet first, for example, your feet, 188 00:10:22,240 --> 00:10:24,520 Speaker 1: the gravity at your feet would be much stronger than 189 00:10:24,600 --> 00:10:28,000 Speaker 1: your head, so you get pulled apart. So I don't 190 00:10:28,000 --> 00:10:30,960 Speaker 1: think it would be much fun. All right, and not 191 00:10:31,120 --> 00:10:35,720 Speaker 1: good is the general message I get from. Yes, our 192 00:10:35,800 --> 00:10:39,720 Speaker 1: council of Advisers recommend against pushing your podcast host into 193 00:10:39,720 --> 00:10:41,520 Speaker 1: a black hole. Although that I heard a lot of 194 00:10:41,559 --> 00:10:44,439 Speaker 1: mentions of pasta, so you know that could be a 195 00:10:44,440 --> 00:10:46,920 Speaker 1: good snack. Yeah, exactly. I said, come prepared. You know, 196 00:10:46,920 --> 00:10:49,680 Speaker 1: we're going on a field trip, so everybody packed spaghetti 197 00:10:49,720 --> 00:10:55,240 Speaker 1: at something. All right, Well, there a lot of interesting answer, 198 00:10:55,280 --> 00:10:57,360 Speaker 1: is there. Some people think you would survive and some 199 00:10:57,400 --> 00:10:59,000 Speaker 1: people don't think you would survive. Yeah. I seem to 200 00:10:59,040 --> 00:11:01,160 Speaker 1: me like these folks have about black holes and if 201 00:11:01,240 --> 00:11:03,440 Speaker 1: even maybe given some thought to what it would be 202 00:11:03,480 --> 00:11:06,000 Speaker 1: like to fall into it before they heard this question, 203 00:11:06,160 --> 00:11:09,679 Speaker 1: so they were pretty well prepared. I was impressed. Good answers, listeners. Yeah, 204 00:11:09,720 --> 00:11:12,920 Speaker 1: and nobody have to push anyone into it either that 205 00:11:12,960 --> 00:11:16,240 Speaker 1: we know off and no people were tossed in the 206 00:11:16,280 --> 00:11:18,960 Speaker 1: black hole for the making of this episode. Yeah, so alright, 207 00:11:19,040 --> 00:11:22,360 Speaker 1: let's jump into it, Daniel. So today we're gonna sort 208 00:11:22,360 --> 00:11:24,880 Speaker 1: of paint the scenario right, like, we're gonna go next 209 00:11:24,880 --> 00:11:27,880 Speaker 1: to a black hole and then we're actually gonna go in. 210 00:11:28,280 --> 00:11:29,840 Speaker 1: We're going to talk about what it's going to be 211 00:11:29,880 --> 00:11:32,160 Speaker 1: like for somebody doing that. That's right, because a lot 212 00:11:32,160 --> 00:11:34,400 Speaker 1: of people mentioned this concern that you might not even 213 00:11:34,480 --> 00:11:36,640 Speaker 1: be able to go into a black hole because you 214 00:11:36,679 --> 00:11:40,240 Speaker 1: would get torn up before you get too close. So 215 00:11:40,520 --> 00:11:42,760 Speaker 1: I guess a question is is even possible to go 216 00:11:42,840 --> 00:11:46,720 Speaker 1: into a black hole and still feel that experience or 217 00:11:46,800 --> 00:11:50,040 Speaker 1: would you just die before even going in? Yeah, And 218 00:11:50,120 --> 00:11:52,679 Speaker 1: it turns out that it depends. It depends on the 219 00:11:52,800 --> 00:11:55,560 Speaker 1: size of the black hole. If you have a really 220 00:11:55,600 --> 00:11:58,680 Speaker 1: small black hole, then the edge the event horizon, the 221 00:11:58,720 --> 00:12:01,840 Speaker 1: part past which nothing thing can escape, is much closer 222 00:12:01,880 --> 00:12:04,600 Speaker 1: to the singularity at the heart, and so it's actually 223 00:12:04,640 --> 00:12:07,080 Speaker 1: difficult to get to the event horizon because you have 224 00:12:07,120 --> 00:12:09,680 Speaker 1: to get sort of closer to the black hole. But 225 00:12:09,840 --> 00:12:12,560 Speaker 1: for a bigger black hole, a massive one like the 226 00:12:12,600 --> 00:12:15,400 Speaker 1: one at the center of our galaxy, the event horizon 227 00:12:15,480 --> 00:12:18,360 Speaker 1: is so far from the singularity that it's safer to 228 00:12:18,400 --> 00:12:21,480 Speaker 1: approach the event horizon. Wait, what what do you mean? 229 00:12:21,640 --> 00:12:24,200 Speaker 1: So it is possible to go into the black hole. 230 00:12:24,240 --> 00:12:27,880 Speaker 1: It is actually possible to survive going over the event 231 00:12:27,920 --> 00:12:30,760 Speaker 1: horizon into the black hole as long as the black 232 00:12:30,760 --> 00:12:33,640 Speaker 1: hole is big enough. That's sort of the twist. All right, Well, 233 00:12:33,800 --> 00:12:36,200 Speaker 1: maybe break that down for us. What what would cause 234 00:12:36,240 --> 00:12:38,280 Speaker 1: me not to survive going into the black hole. So 235 00:12:38,320 --> 00:12:40,440 Speaker 1: the reason that a black hole pulls you apart this 236 00:12:40,600 --> 00:12:44,400 Speaker 1: spaghettification is due to the strength of its gravitational field, 237 00:12:44,400 --> 00:12:47,560 Speaker 1: but also due to how fast that gravitational field is 238 00:12:47,679 --> 00:12:50,920 Speaker 1: changing the slope of the gravitational field, if you will, 239 00:12:51,080 --> 00:12:53,600 Speaker 1: Because you are not a tiny point, you are an 240 00:12:53,640 --> 00:12:56,319 Speaker 1: actual physical thing. You have a front and a back 241 00:12:56,400 --> 00:12:59,120 Speaker 1: and two sides. And if the black holes pulling on 242 00:12:59,200 --> 00:13:02,160 Speaker 1: for example, you're head at a different strength than is 243 00:13:02,200 --> 00:13:05,160 Speaker 1: pulling on your feet, then effectively it's pulling your head 244 00:13:05,400 --> 00:13:08,120 Speaker 1: off of your body. It's tearing you apart. That's what 245 00:13:08,160 --> 00:13:11,880 Speaker 1: we call tidal forces. When gravitational forces are different on 246 00:13:11,880 --> 00:13:14,480 Speaker 1: one side of an object and on the other, that's 247 00:13:14,520 --> 00:13:17,120 Speaker 1: the same as having a force pull that thing apart. 248 00:13:18,000 --> 00:13:20,720 Speaker 1: And that's happening like right now. It's not something that 249 00:13:20,800 --> 00:13:23,360 Speaker 1: just happens near a black hole. Is like if I 250 00:13:23,400 --> 00:13:25,800 Speaker 1: stand up here on Earth, the Earth is pulling my 251 00:13:26,000 --> 00:13:29,400 Speaker 1: feet more than it's pulling my head. That's right. The 252 00:13:29,440 --> 00:13:31,600 Speaker 1: Earth is trying to pull your head off your body 253 00:13:31,880 --> 00:13:35,440 Speaker 1: right now. But the slope of the Earth's gravitation of field, 254 00:13:35,480 --> 00:13:37,679 Speaker 1: how much different it is at your feet and at 255 00:13:37,679 --> 00:13:41,000 Speaker 1: your head, is very, very small, and your body is 256 00:13:41,040 --> 00:13:44,120 Speaker 1: strong enough to resist that tension. You can resist the 257 00:13:44,160 --> 00:13:47,280 Speaker 1: tidal force of the Earth. So here on Earth it's weak. 258 00:13:47,320 --> 00:13:51,880 Speaker 1: Post gravity is relatively weak pasta compared to a black hole. 259 00:13:51,920 --> 00:13:54,760 Speaker 1: But in a black hole gravity is stronger, and so 260 00:13:54,800 --> 00:13:56,720 Speaker 1: the difference between the gravity and my head and my 261 00:13:56,800 --> 00:13:59,960 Speaker 1: legs is stronger. So that could pull me apart. That's right, 262 00:14:00,000 --> 00:14:02,079 Speaker 1: because these tidal forces, the thing that pulls you apart 263 00:14:02,120 --> 00:14:05,000 Speaker 1: depends on the forces being different at your foot and 264 00:14:05,040 --> 00:14:07,840 Speaker 1: at your head. And as you get closer to a 265 00:14:07,880 --> 00:14:10,080 Speaker 1: black hole, closer to the center of the black hole, 266 00:14:10,320 --> 00:14:14,360 Speaker 1: the curvature increases, the difference of the gravitational force at 267 00:14:14,400 --> 00:14:17,080 Speaker 1: your head and your foot increases. Now the Earth, you 268 00:14:17,120 --> 00:14:19,440 Speaker 1: can't get that much closer to the Earth than its surface. 269 00:14:19,480 --> 00:14:22,840 Speaker 1: If you dug into the Earth, the gravitational forces actually 270 00:14:22,840 --> 00:14:24,520 Speaker 1: start to weaken because you have a lot of the 271 00:14:24,520 --> 00:14:26,800 Speaker 1: mass on the outside of you. The cool thing about 272 00:14:26,800 --> 00:14:28,960 Speaker 1: a black hole is that it has so much mass 273 00:14:29,000 --> 00:14:32,000 Speaker 1: in a tiny little area, so you can get really 274 00:14:32,080 --> 00:14:34,920 Speaker 1: close to it without losing any of the gravitational force. 275 00:14:34,960 --> 00:14:37,920 Speaker 1: It just gets stronger and stronger and stronger. So that's 276 00:14:37,920 --> 00:14:40,680 Speaker 1: why for a black hole, you can get close enough 277 00:14:40,760 --> 00:14:43,160 Speaker 1: to it that it has an event horizon, and that 278 00:14:43,240 --> 00:14:45,920 Speaker 1: the tidal forces, these things pulling you apart, can be 279 00:14:45,960 --> 00:14:49,560 Speaker 1: stronger than your body can withstand. Now, I think that 280 00:14:49,880 --> 00:14:54,280 Speaker 1: usually people talk about that happening before you enter the 281 00:14:54,320 --> 00:14:56,720 Speaker 1: black hole. But you're telling me that it's not necessarily 282 00:14:56,920 --> 00:15:00,160 Speaker 1: Like I won't get spaghettified necessarily outside of the black hole. 283 00:15:00,200 --> 00:15:02,640 Speaker 1: I could get spaghettified inside of the black hole, in 284 00:15:02,640 --> 00:15:06,120 Speaker 1: which case I could technically go into a black hole. Yeah, exactly. 285 00:15:06,280 --> 00:15:08,960 Speaker 1: The threshold of which you get spaghettified depends on the 286 00:15:09,000 --> 00:15:11,160 Speaker 1: mass of the black hole. Now, so it is the 287 00:15:11,200 --> 00:15:13,160 Speaker 1: size of the black hole. But there's this point where 288 00:15:13,160 --> 00:15:15,880 Speaker 1: they cross. If a black hole is big enough, then 289 00:15:15,880 --> 00:15:19,480 Speaker 1: the sort of spaghettification point is inside the event horizon. 290 00:15:19,920 --> 00:15:22,440 Speaker 1: If the black hole is small enough, then the spaghetification 291 00:15:22,440 --> 00:15:25,200 Speaker 1: point is outside the event horizon. You get torn apart 292 00:15:25,440 --> 00:15:28,040 Speaker 1: before you go inside to a small black hole you 293 00:15:28,080 --> 00:15:30,440 Speaker 1: get torn apart after you go inside. For a really 294 00:15:30,520 --> 00:15:33,080 Speaker 1: big black hole, that's because the size of the black 295 00:15:33,080 --> 00:15:35,760 Speaker 1: hole where the edge of the event horizon is depends 296 00:15:35,840 --> 00:15:39,360 Speaker 1: differently on the mass than the spaghettification point. Right, And 297 00:15:39,400 --> 00:15:41,520 Speaker 1: when you say event horizon, you mean like the actual 298 00:15:42,120 --> 00:15:44,480 Speaker 1: like what this is considered the edge of the black hole, 299 00:15:44,560 --> 00:15:47,240 Speaker 1: Like that's the point where light can't escape exactly. And 300 00:15:47,240 --> 00:15:49,600 Speaker 1: that's just an arbitrary definition. We say the black hole 301 00:15:49,680 --> 00:15:52,880 Speaker 1: begins at the event horizon, the place where a ray 302 00:15:52,920 --> 00:15:56,680 Speaker 1: of light, even if pointed exactly away from the black hole, 303 00:15:57,080 --> 00:15:59,200 Speaker 1: still would not be able to escape. All right, So 304 00:15:59,280 --> 00:16:01,440 Speaker 1: then I guess then technically, if I wanted to go 305 00:16:01,640 --> 00:16:04,640 Speaker 1: into a black hole like pass the event horizon, I 306 00:16:04,680 --> 00:16:08,520 Speaker 1: need to pick a big black hole, right, because the 307 00:16:08,560 --> 00:16:12,040 Speaker 1: little one would turn me apart before I go into it. Yeah, 308 00:16:12,080 --> 00:16:13,760 Speaker 1: that's right. You need to pick a black hole about 309 00:16:13,760 --> 00:16:17,120 Speaker 1: a thousand times bigger than the mass of our sun 310 00:16:17,560 --> 00:16:20,560 Speaker 1: before it's safe to enter, before coming to the event 311 00:16:20,600 --> 00:16:23,480 Speaker 1: horizon will not tear you apart from the tidal forces. 312 00:16:24,320 --> 00:16:26,280 Speaker 1: That doesn't sound like a lot like I would expect to, 313 00:16:26,800 --> 00:16:28,880 Speaker 1: you know, decent sized black hole to be more than 314 00:16:28,920 --> 00:16:31,480 Speaker 1: a thousand times the mass. Yeah, and there are big 315 00:16:31,520 --> 00:16:33,240 Speaker 1: black holes out there that are much bigger than that. 316 00:16:33,240 --> 00:16:34,880 Speaker 1: In fact, there's a bit of a gap. There are 317 00:16:34,920 --> 00:16:37,160 Speaker 1: a few black holes out there that are like ten 318 00:16:37,320 --> 00:16:39,640 Speaker 1: or fifty or eighty times the mass of our sun. 319 00:16:39,880 --> 00:16:42,840 Speaker 1: These come from stars just collapsing into a black hole. 320 00:16:43,080 --> 00:16:44,600 Speaker 1: And then there are black holes in this sort of 321 00:16:44,680 --> 00:16:47,720 Speaker 1: million sun range, and these are the black holes at 322 00:16:47,720 --> 00:16:50,720 Speaker 1: the centers of galaxies, these super massive black holes. There 323 00:16:50,720 --> 00:16:53,520 Speaker 1: actually aren't a lot of black holes in that intermediate 324 00:16:53,640 --> 00:16:56,520 Speaker 1: range because there isn't a process to form them, unless there, 325 00:16:56,560 --> 00:16:59,520 Speaker 1: of course, are primordial black holes that nobody's seen those. 326 00:16:59,760 --> 00:17:02,440 Speaker 1: So your options are black holes that are sort of 327 00:17:02,480 --> 00:17:04,439 Speaker 1: small like the mass of our sun, which would be 328 00:17:04,480 --> 00:17:07,920 Speaker 1: too dangerous to get close to, or really really big 329 00:17:07,960 --> 00:17:11,719 Speaker 1: ones which are pretty safe to approach. There's no medium option, 330 00:17:12,400 --> 00:17:15,399 Speaker 1: like you can only buy a compact car or a 331 00:17:15,440 --> 00:17:18,239 Speaker 1: giant suv. Yeah, but the giant SUVs are safer, and 332 00:17:18,320 --> 00:17:20,919 Speaker 1: the bigger they get, the safer they are, because the 333 00:17:20,920 --> 00:17:24,040 Speaker 1: bigger they get, the further from the singularity the event 334 00:17:24,080 --> 00:17:26,920 Speaker 1: horizon is, and so the safer it is to go 335 00:17:27,119 --> 00:17:29,760 Speaker 1: across that event horizon, right, And the bigger black holes 336 00:17:29,760 --> 00:17:33,120 Speaker 1: are also harder to park, so there's a trade off. Yeah, 337 00:17:33,160 --> 00:17:35,280 Speaker 1: well you're going to the black hole. Nobody's gonna bring 338 00:17:35,359 --> 00:17:37,480 Speaker 1: the black hole to you. What do you mean, no 339 00:17:37,560 --> 00:17:41,119 Speaker 1: matter how important you are. Well, technically everyone near a 340 00:17:41,160 --> 00:17:43,280 Speaker 1: black hole pools on the black hole. So the technically 341 00:17:43,280 --> 00:17:45,960 Speaker 1: the black hole moves a little bit towards you tube. Yeah, exactly, 342 00:17:46,240 --> 00:17:48,800 Speaker 1: just like blowing in the wind. You know, it has 343 00:17:48,800 --> 00:17:50,640 Speaker 1: almost no impact. But you're right, You and the black 344 00:17:50,680 --> 00:17:53,560 Speaker 1: hole are a system, and together you're orbiting the center 345 00:17:53,600 --> 00:17:56,040 Speaker 1: of mass, which is basically the black hole. You're basically 346 00:17:56,080 --> 00:17:58,240 Speaker 1: negligible when it comes to black holes. Well, it sounds 347 00:17:58,240 --> 00:18:00,040 Speaker 1: like if you're curious to see what's inside of a 348 00:18:00,040 --> 00:18:02,199 Speaker 1: black hole and you want to get inside past the 349 00:18:02,240 --> 00:18:04,680 Speaker 1: event horizon, you need to pick a big one, otherwise 350 00:18:04,720 --> 00:18:07,960 Speaker 1: you'll be torn apart before you even get there. Right, Well, 351 00:18:08,040 --> 00:18:10,720 Speaker 1: let's get into what you would actually see as you 352 00:18:10,760 --> 00:18:13,160 Speaker 1: go into the black hole, and let's talk about what's 353 00:18:13,160 --> 00:18:15,760 Speaker 1: inside of it. But first let's take a quick break. 354 00:18:22,760 --> 00:18:24,760 Speaker 1: All right. I know, we are taking the probably the 355 00:18:24,760 --> 00:18:28,560 Speaker 1: worst field trip anyone can take, which is to go 356 00:18:28,760 --> 00:18:32,080 Speaker 1: inside of a black hole. He probably wouldn't come back 357 00:18:32,119 --> 00:18:36,680 Speaker 1: in time for races or the school bell. But we're 358 00:18:36,680 --> 00:18:39,040 Speaker 1: talking about what it would be like to go into 359 00:18:39,240 --> 00:18:41,640 Speaker 1: into it, Like what would you experience, what would you see, 360 00:18:41,640 --> 00:18:45,160 Speaker 1: what would you hear or feel as you go in? Yeah, 361 00:18:45,160 --> 00:18:46,560 Speaker 1: it would be pretty fun. I think it would be 362 00:18:46,600 --> 00:18:48,240 Speaker 1: an awesome field trip. I mean, it's not when you 363 00:18:48,280 --> 00:18:50,639 Speaker 1: could return from and so the permission slip would be 364 00:18:50,680 --> 00:18:54,119 Speaker 1: pretty crazy. But yeah, I think you might learn something 365 00:18:54,200 --> 00:18:56,960 Speaker 1: deep and true about the universe. You might reveal a secret, 366 00:18:57,119 --> 00:18:59,600 Speaker 1: an answer nobody knows, and so I think it'd be 367 00:18:59,600 --> 00:19:01,879 Speaker 1: pretty someome. I would definitely sign myself up for this 368 00:19:01,920 --> 00:19:05,520 Speaker 1: field trip really, like tomorrow, if somebody said, hey, Daniel, 369 00:19:05,560 --> 00:19:06,840 Speaker 1: would you like to go into a black hole and 370 00:19:06,880 --> 00:19:08,800 Speaker 1: learn the secrets of the universe? You would jump in? 371 00:19:09,760 --> 00:19:11,440 Speaker 1: You know, I might. I don't think I would take 372 00:19:11,480 --> 00:19:14,480 Speaker 1: a trip to Mars just for like planting a flag 373 00:19:14,560 --> 00:19:16,840 Speaker 1: on Mars, but to know the answer to one of 374 00:19:16,840 --> 00:19:20,040 Speaker 1: the deepest questions in the universe. I might, just because 375 00:19:20,080 --> 00:19:23,600 Speaker 1: remember that black holes are where general relativity breaks down, 376 00:19:24,040 --> 00:19:26,679 Speaker 1: is where we know that our theory of how space 377 00:19:26,720 --> 00:19:30,160 Speaker 1: and mass bend and dance with each other doesn't work anymore. 378 00:19:30,560 --> 00:19:33,359 Speaker 1: And something quantum, something new, something weird is going on 379 00:19:33,520 --> 00:19:36,280 Speaker 1: in there, and the only place we think general relativity 380 00:19:36,359 --> 00:19:39,080 Speaker 1: does break down is inside these black holes, and so 381 00:19:39,160 --> 00:19:41,919 Speaker 1: they literally hold secrets to really deep questions about the 382 00:19:41,960 --> 00:19:45,280 Speaker 1: universe that physicists are struggling over. So it's sort of 383 00:19:45,280 --> 00:19:47,600 Speaker 1: like asking, if I had an answer to a deep 384 00:19:47,680 --> 00:19:50,080 Speaker 1: question about the universe in this envelope, would you tear 385 00:19:50,119 --> 00:19:52,159 Speaker 1: it open? Yeah? Of course I would. I would shred 386 00:19:52,200 --> 00:19:54,680 Speaker 1: it instantly, right, even if the envelope tells you apart 387 00:19:55,880 --> 00:19:59,760 Speaker 1: they never come back. Well that's really interesting, because I mean, 388 00:20:00,040 --> 00:20:02,520 Speaker 1: you would give up knowing everything else about dear life 389 00:20:03,160 --> 00:20:05,679 Speaker 1: just to get this one secret. I think you'd be 390 00:20:05,720 --> 00:20:08,320 Speaker 1: really tempting. Yeah. I mean, fortunately, nobody's going to actually 391 00:20:08,320 --> 00:20:10,520 Speaker 1: ever offer me this, so I can bluff as much 392 00:20:10,520 --> 00:20:12,600 Speaker 1: as i'd like. Oh I see, I see, we can 393 00:20:12,800 --> 00:20:16,919 Speaker 1: have any opinion really doesn't matter, all right, So what 394 00:20:16,920 --> 00:20:18,680 Speaker 1: would it be like? So I picked the big black 395 00:20:18,680 --> 00:20:21,879 Speaker 1: hole because those are safer to approach than little black holes, 396 00:20:21,920 --> 00:20:24,119 Speaker 1: which is kind of weird, but I guess that's how 397 00:20:24,160 --> 00:20:27,240 Speaker 1: the math works. So now I picked a really big 398 00:20:27,240 --> 00:20:29,879 Speaker 1: one and I'm approaching it. What do I see? Well, 399 00:20:29,880 --> 00:20:32,119 Speaker 1: the first thing you see is the thing around the 400 00:20:32,200 --> 00:20:35,720 Speaker 1: doughnut around the black hole. Because most black holes are active, 401 00:20:35,760 --> 00:20:38,720 Speaker 1: they're still sucking stuff into them. But stuff doesn't fall 402 00:20:38,800 --> 00:20:41,320 Speaker 1: directly into the black hole because it still has some 403 00:20:41,440 --> 00:20:44,320 Speaker 1: angular momentum, which means it's spinning the way that we're 404 00:20:44,359 --> 00:20:47,600 Speaker 1: spinning around the Sun for example, without just falling in. 405 00:20:48,040 --> 00:20:51,280 Speaker 1: So the black hole has this stuff in orbit around it. Also, 406 00:20:51,680 --> 00:20:54,760 Speaker 1: that's called the accretion disc. It's the swirling mass of 407 00:20:54,840 --> 00:20:57,399 Speaker 1: gas and dust and doing all sorts of crazy stuff, 408 00:20:57,880 --> 00:21:00,280 Speaker 1: and some of it is falling in. But to all end, 409 00:21:00,280 --> 00:21:02,520 Speaker 1: it has to like lose some energy, has to give 410 00:21:02,600 --> 00:21:05,280 Speaker 1: up some angular momentum, and it does that by like 411 00:21:05,320 --> 00:21:08,880 Speaker 1: getting squeezed and glowing and giving off light. I guess. 412 00:21:08,720 --> 00:21:11,440 Speaker 1: In technically, a black hole is not that different than 413 00:21:11,520 --> 00:21:14,159 Speaker 1: like a sun, for example, so it would have stuff 414 00:21:14,320 --> 00:21:17,600 Speaker 1: orbiting around it. Yeah, it has hot gas orbiting around it, 415 00:21:17,640 --> 00:21:21,120 Speaker 1: and that hot gas is glowing. It's not having fusion necessarily, 416 00:21:21,400 --> 00:21:23,320 Speaker 1: but it's a very bright emitter. These are some of 417 00:21:23,359 --> 00:21:26,600 Speaker 1: the brightest things in the galaxy, these disks of gas 418 00:21:26,640 --> 00:21:28,960 Speaker 1: around a black hole. When they get really intense, you 419 00:21:29,000 --> 00:21:32,000 Speaker 1: call them quasars or even blaze ours, and they are 420 00:21:32,160 --> 00:21:34,960 Speaker 1: super duper crazy bright, So it's sort of ironic that 421 00:21:35,040 --> 00:21:37,000 Speaker 1: some of the brightest things in the universe are next 422 00:21:37,040 --> 00:21:39,360 Speaker 1: to some of the blackest things in the universe. Right, 423 00:21:39,400 --> 00:21:42,400 Speaker 1: But it's also not true that every black hole has 424 00:21:42,400 --> 00:21:44,959 Speaker 1: a bright accretion this like, some black holes could just 425 00:21:45,000 --> 00:21:47,240 Speaker 1: be like sitting there, right. Yeah, they certainly could be, 426 00:21:47,600 --> 00:21:49,760 Speaker 1: and it just depends on what's around it. If you 427 00:21:49,760 --> 00:21:52,000 Speaker 1: have a primordial black hole that was created during the 428 00:21:52,040 --> 00:21:54,480 Speaker 1: Big Bang and it's just like floating out around there 429 00:21:54,520 --> 00:21:56,760 Speaker 1: and there's nothing to eat, then it could just be 430 00:21:56,880 --> 00:22:00,800 Speaker 1: silently stealthily sitting there, totally black. The creation disc just 431 00:22:00,880 --> 00:22:03,560 Speaker 1: comes from stuff that's sort of on deck about to 432 00:22:03,600 --> 00:22:05,840 Speaker 1: fall into the black hole. But you're right, it's not 433 00:22:05,880 --> 00:22:09,080 Speaker 1: necessary that there's anything like that there. But if we're 434 00:22:09,119 --> 00:22:11,920 Speaker 1: choosing a supermassive black hole, the only way that happened 435 00:22:12,280 --> 00:22:14,200 Speaker 1: is if it's at the center of a galaxy, which 436 00:22:14,200 --> 00:22:16,400 Speaker 1: means it's been sucking in gas and dust and it's 437 00:22:16,400 --> 00:22:19,280 Speaker 1: surrounded by stuff. So you're pretty likely to find an 438 00:22:19,280 --> 00:22:23,320 Speaker 1: accretion disk around a supermassive black hole. Okay, right, that's right, 439 00:22:23,320 --> 00:22:25,520 Speaker 1: because we picked a big one to go into, so 440 00:22:25,560 --> 00:22:28,639 Speaker 1: it's it probably has that disk, and so as you 441 00:22:28,680 --> 00:22:31,040 Speaker 1: approach it, you probably want to avoid that disc, right, 442 00:22:31,080 --> 00:22:33,240 Speaker 1: and it's going to be a flat disc, so it 443 00:22:33,240 --> 00:22:35,920 Speaker 1: it's not that hard to avoid because it's pretty hot, 444 00:22:36,040 --> 00:22:38,520 Speaker 1: that's right. It's pretty hot and pretty nasty. And say 445 00:22:38,560 --> 00:22:39,960 Speaker 1: you want to avoid that, you want to come in 446 00:22:39,960 --> 00:22:42,199 Speaker 1: from the top or from the side, unless it's one 447 00:22:42,200 --> 00:22:44,760 Speaker 1: of these quasars, in which case it also has a crazy, 448 00:22:44,880 --> 00:22:48,359 Speaker 1: you know, spinning magnetic field that's beaming a huge beam 449 00:22:48,400 --> 00:22:50,440 Speaker 1: of light along the north and south axis, So you 450 00:22:50,480 --> 00:22:52,480 Speaker 1: want to come in a bit of an angle. But yeah, 451 00:22:52,560 --> 00:22:54,520 Speaker 1: there's an opening there. I mean, this is a black 452 00:22:54,520 --> 00:22:56,520 Speaker 1: hole field trip, but we still want to keep safety 453 00:22:56,520 --> 00:22:59,040 Speaker 1: in mount right, Yeah. And so the acretion disc is 454 00:22:59,200 --> 00:23:02,480 Speaker 1: at about three and a half times the width of 455 00:23:02,480 --> 00:23:04,920 Speaker 1: the black hole, right. Yeah. If you say the event 456 00:23:04,960 --> 00:23:07,760 Speaker 1: horizon is the radius of the black hole, then the 457 00:23:07,800 --> 00:23:10,240 Speaker 1: accretion disc sort of ends around three and a half 458 00:23:10,280 --> 00:23:12,879 Speaker 1: times that. Anything less than that and the stuff is 459 00:23:12,880 --> 00:23:15,680 Speaker 1: going to fall into the black hole. So everything at 460 00:23:15,760 --> 00:23:17,960 Speaker 1: that point and a little bit further out can sort 461 00:23:17,960 --> 00:23:20,879 Speaker 1: of stably orbit the black hole for a while until 462 00:23:20,920 --> 00:23:24,040 Speaker 1: it loses its energy through collision or radiation or whatever, 463 00:23:24,280 --> 00:23:27,240 Speaker 1: and then eventually falls in. But you don't find much 464 00:23:27,280 --> 00:23:29,720 Speaker 1: gas and dust less than three and a half because 465 00:23:29,760 --> 00:23:31,600 Speaker 1: that stuff has already falling in. I see, it's kind 466 00:23:31,600 --> 00:23:33,240 Speaker 1: of like the rings of Saturn. Like the rings of 467 00:23:33,280 --> 00:23:36,680 Speaker 1: Saturn are a ring, they don't go all the way 468 00:23:36,680 --> 00:23:39,320 Speaker 1: to the surface of the planet because stuff that's closer 469 00:23:39,359 --> 00:23:41,560 Speaker 1: to the planet falls in. So it is like it's 470 00:23:41,600 --> 00:23:43,840 Speaker 1: hanging out there in space. Yeah, exactly. So that's sort 471 00:23:43,840 --> 00:23:46,600 Speaker 1: of the inner edge of the accretion disc of the 472 00:23:46,600 --> 00:23:48,680 Speaker 1: black holes three and a half times of radius for 473 00:23:48,800 --> 00:23:51,320 Speaker 1: just that same reason. Yeah, alright, so I'm going into 474 00:23:51,320 --> 00:23:54,720 Speaker 1: the black hole, I move past the acreation disk. What 475 00:23:54,800 --> 00:23:57,120 Speaker 1: am I seeing now? So now what you're looking at 476 00:23:57,480 --> 00:23:59,520 Speaker 1: is the shadow of the black hole. And we have 477 00:23:59,560 --> 00:24:01,879 Speaker 1: to keep in mind as we get closer and closer 478 00:24:01,920 --> 00:24:04,560 Speaker 1: to the black hole, that space around the black hole 479 00:24:04,720 --> 00:24:07,600 Speaker 1: is bent. Remember that space is not just the backdrop, 480 00:24:07,720 --> 00:24:10,920 Speaker 1: is not just the emptiness. There's a dance between space 481 00:24:10,960 --> 00:24:14,359 Speaker 1: and mass. Mass tells space how to bend, and space 482 00:24:14,400 --> 00:24:17,680 Speaker 1: tells mass and light how to move. So that means 483 00:24:17,720 --> 00:24:20,440 Speaker 1: that photons don't travel in straight line. So what you're 484 00:24:20,480 --> 00:24:24,639 Speaker 1: looking at, what you see isn't necessarily what's there and 485 00:24:24,680 --> 00:24:27,600 Speaker 1: the environment of Earth where light mostly travels in straight lines. 486 00:24:27,640 --> 00:24:29,920 Speaker 1: You can assume that you're seeing things as they are, 487 00:24:30,359 --> 00:24:32,679 Speaker 1: but if there are lenses and distortion happening, then you 488 00:24:32,760 --> 00:24:36,440 Speaker 1: expect to see an image which doesn't necessarily correspond exactly 489 00:24:36,520 --> 00:24:39,400 Speaker 1: to what's literally there. But what you see in front 490 00:24:39,440 --> 00:24:42,600 Speaker 1: of you is this big black circle, this shadow of 491 00:24:42,640 --> 00:24:45,280 Speaker 1: the black hole that's like two and a half times 492 00:24:45,280 --> 00:24:48,320 Speaker 1: the size of the actual event horizon, and you'll see 493 00:24:48,359 --> 00:24:51,080 Speaker 1: it be all black. And why is that? Why is 494 00:24:51,080 --> 00:24:53,400 Speaker 1: the black circle that I see bigger than the actual 495 00:24:53,440 --> 00:24:56,360 Speaker 1: black circle of the black hole Because anywhere in that 496 00:24:56,440 --> 00:24:59,159 Speaker 1: black shadow there's no path for light to get to 497 00:24:59,400 --> 00:25:02,199 Speaker 1: your eye. Is like if you traced it backwards, if 498 00:25:02,200 --> 00:25:04,760 Speaker 1: you started from your eyeball and trace the path of light, 499 00:25:05,119 --> 00:25:07,840 Speaker 1: that light would always end up in the black hole. So, 500 00:25:07,920 --> 00:25:10,480 Speaker 1: for example, what you're looking at when you look straight 501 00:25:10,560 --> 00:25:13,040 Speaker 1: at the heart of the black hole is the black hole, 502 00:25:13,080 --> 00:25:15,720 Speaker 1: and no light comes from there, obviously, so you see black. 503 00:25:16,240 --> 00:25:18,600 Speaker 1: But if you look above the edge of the black hole, 504 00:25:18,640 --> 00:25:21,359 Speaker 1: like larger than the rays the black hole, then the 505 00:25:21,480 --> 00:25:23,400 Speaker 1: light would come from the back of the black hole 506 00:25:23,440 --> 00:25:25,879 Speaker 1: and then curve around the black hole to your eye. 507 00:25:26,160 --> 00:25:28,560 Speaker 1: So what you're actually seeing there is sort of the 508 00:25:28,600 --> 00:25:30,560 Speaker 1: path light would take to get to the back of 509 00:25:30,600 --> 00:25:33,320 Speaker 1: the black hole, but again, no light is emitted from 510 00:25:33,359 --> 00:25:35,400 Speaker 1: the back of the black hole. Yeah, so that means 511 00:25:35,440 --> 00:25:37,840 Speaker 1: that I'm actually seeing kind of the back of the 512 00:25:37,880 --> 00:25:41,119 Speaker 1: black hole right like above the actual black hole. I'm 513 00:25:41,160 --> 00:25:43,399 Speaker 1: actually seeing the back of it because it's sort of 514 00:25:44,200 --> 00:25:47,880 Speaker 1: the light gets distorted from the back around the black 515 00:25:47,880 --> 00:25:50,359 Speaker 1: hole and onto my eye. It's sort of like a 516 00:25:50,440 --> 00:25:55,119 Speaker 1: lens like it's being magnified in three D exactly. Another 517 00:25:55,160 --> 00:25:57,119 Speaker 1: way to think about it is put a star on 518 00:25:57,160 --> 00:25:59,000 Speaker 1: the other side of the black hole, like a really 519 00:25:59,040 --> 00:26:02,600 Speaker 1: bright star. Would you see it's light creeping over the 520 00:26:02,720 --> 00:26:05,200 Speaker 1: edge of the event horizon. The answer is no, because 521 00:26:05,240 --> 00:26:08,840 Speaker 1: those photons would get bent down and then sucked into 522 00:26:08,840 --> 00:26:11,680 Speaker 1: the black hole. Even if they don't hit the event horizon. 523 00:26:11,760 --> 00:26:14,879 Speaker 1: As they pass over it, the black hole curves their path, 524 00:26:14,960 --> 00:26:17,359 Speaker 1: It slurps them down, and they get sucked into the 525 00:26:17,359 --> 00:26:20,439 Speaker 1: black hole eventually, so you don't see that light. So 526 00:26:20,520 --> 00:26:22,359 Speaker 1: the first light that you could see, the light that 527 00:26:22,359 --> 00:26:25,560 Speaker 1: would survive being passed to your eyes is about two 528 00:26:25,600 --> 00:26:28,159 Speaker 1: and a half times the event horizon. That's why we 529 00:26:28,240 --> 00:26:31,160 Speaker 1: talked about seeing an image of the black hole. It's 530 00:26:31,200 --> 00:26:33,800 Speaker 1: not the literal black hole itself. It's a distortion of 531 00:26:33,840 --> 00:26:36,840 Speaker 1: the space that makes it look bigger. It's like a mirrage, 532 00:26:37,119 --> 00:26:39,680 Speaker 1: like it's the black hole is pretending to be bigger 533 00:26:39,720 --> 00:26:42,480 Speaker 1: than it is. That's right. It's like a black cat 534 00:26:42,560 --> 00:26:45,240 Speaker 1: that's gotten really mad, and it's like and it posts 535 00:26:45,280 --> 00:26:48,760 Speaker 1: up and post itself up. Yeah, there you go. Black 536 00:26:48,800 --> 00:26:51,680 Speaker 1: cats black holes both are bad luck if they cross 537 00:26:51,680 --> 00:26:54,720 Speaker 1: your path, that's right. And so maybe the black hole 538 00:26:54,800 --> 00:26:56,480 Speaker 1: is more scared of us than we are of it. 539 00:26:56,800 --> 00:26:59,720 Speaker 1: The black hole is full of black cats, which case, 540 00:26:59,720 --> 00:27:02,840 Speaker 1: they will tear you apart. Also, I think we just 541 00:27:02,920 --> 00:27:05,879 Speaker 1: figured out we just answered the deepest question about quantum 542 00:27:05,880 --> 00:27:08,360 Speaker 1: gravity right there. All right, So I see the shadow 543 00:27:08,640 --> 00:27:12,000 Speaker 1: and now but now I'm getting closer, even closer than 544 00:27:12,040 --> 00:27:14,520 Speaker 1: the shadow, or can I enter the shadow? Well, as 545 00:27:14,560 --> 00:27:17,720 Speaker 1: you get closer this shadow, this circle of black that 546 00:27:17,720 --> 00:27:19,359 Speaker 1: you see in front of you, it starts out like 547 00:27:19,359 --> 00:27:21,040 Speaker 1: two and a half times the rays of the black hole, 548 00:27:21,200 --> 00:27:23,880 Speaker 1: it just gets bigger and bigger in your field of view. 549 00:27:24,119 --> 00:27:26,399 Speaker 1: And not just because you're getting closer to it, but 550 00:27:26,440 --> 00:27:30,640 Speaker 1: because the distortion of space is magnifying it more and more. Right, 551 00:27:30,880 --> 00:27:32,639 Speaker 1: So as you get closer and closer to it, it 552 00:27:32,760 --> 00:27:35,399 Speaker 1: sort of grows and takes up more and more of 553 00:27:35,440 --> 00:27:38,119 Speaker 1: your field of view, and it gets bigger and bigger 554 00:27:38,160 --> 00:27:41,000 Speaker 1: and bigger. But there is awesome stuff that happens even 555 00:27:41,080 --> 00:27:43,959 Speaker 1: before you get to the event horizon. Yeah, what happened. Well, 556 00:27:44,000 --> 00:27:46,200 Speaker 1: once you get to like one and a half times 557 00:27:46,200 --> 00:27:49,160 Speaker 1: the event horizon, this is the last point where light 558 00:27:49,280 --> 00:27:52,960 Speaker 1: can orbit the black hole stably. Remember the event horizon 559 00:27:53,359 --> 00:27:57,000 Speaker 1: is where light pointed outwards can't escape the black hole. 560 00:27:57,480 --> 00:28:00,160 Speaker 1: But even before that, light pointed inwards won't just gave 561 00:28:00,240 --> 00:28:02,240 Speaker 1: the black hole. Right, If you're two times the size 562 00:28:02,280 --> 00:28:04,560 Speaker 1: of the event horizon and you shine a flashlight into 563 00:28:04,560 --> 00:28:07,280 Speaker 1: the black hole, boom, it's going to get slurped in. Now, 564 00:28:07,280 --> 00:28:09,560 Speaker 1: if you're one and a half times the event horizon 565 00:28:09,920 --> 00:28:12,719 Speaker 1: and you shine a flashlight sideways so that it's not 566 00:28:12,760 --> 00:28:15,439 Speaker 1: going towards or away from the black hole, and that 567 00:28:15,520 --> 00:28:18,680 Speaker 1: light has just enough power to bend all the way 568 00:28:18,720 --> 00:28:20,800 Speaker 1: around the black hole and come back and hit you 569 00:28:20,840 --> 00:28:25,040 Speaker 1: in the back of the head. What light can orbit 570 00:28:25,200 --> 00:28:28,200 Speaker 1: a black hole? But light has no mass. Light has 571 00:28:28,240 --> 00:28:31,520 Speaker 1: no mass. But remember space is curved, and light doesn't 572 00:28:31,560 --> 00:28:34,240 Speaker 1: move in straight lines. It moves in the shortest path. 573 00:28:34,720 --> 00:28:38,040 Speaker 1: And what gravity is is the bending of space, which 574 00:28:38,160 --> 00:28:42,160 Speaker 1: changes effectively what is the shortest path between two things? 575 00:28:42,160 --> 00:28:44,480 Speaker 1: Like the reason that the Earth is going around the 576 00:28:44,480 --> 00:28:46,600 Speaker 1: Sun is not because the Earth has mass, but because 577 00:28:46,680 --> 00:28:49,840 Speaker 1: the Sun has bent the shape of space. So it's 578 00:28:49,840 --> 00:28:52,280 Speaker 1: more natural for this Earth to go in this circle. 579 00:28:52,560 --> 00:28:55,200 Speaker 1: And so light also can follow these curved paths when 580 00:28:55,280 --> 00:28:57,120 Speaker 1: space is bent. We see that all the time in 581 00:28:57,160 --> 00:29:00,560 Speaker 1: gravitational lensing, etcetera. And so what how upens here is 582 00:29:00,640 --> 00:29:03,600 Speaker 1: light essentially is orbiting the black hole. So if you 583 00:29:03,640 --> 00:29:06,320 Speaker 1: shine a flashlight, it will illuminate the back of your 584 00:29:06,320 --> 00:29:08,320 Speaker 1: own head, or if you don't have a flashlight, you 585 00:29:08,440 --> 00:29:11,200 Speaker 1: look out and you'll see photons from the back of 586 00:29:11,240 --> 00:29:14,000 Speaker 1: your own head. Whoa I've always wanted to know at 587 00:29:14,000 --> 00:29:16,760 Speaker 1: the back of my head looks like And you can't 588 00:29:16,760 --> 00:29:18,680 Speaker 1: just ask somebody around you. You have to take a 589 00:29:18,720 --> 00:29:20,880 Speaker 1: field chip to the black hole. That's the most efficient 590 00:29:20,920 --> 00:29:25,200 Speaker 1: way just to find that. It's easier than putting you 591 00:29:25,200 --> 00:29:28,000 Speaker 1: a couple of mirrors. And so at that point, any 592 00:29:28,080 --> 00:29:31,240 Speaker 1: light that's pointed at all towards the black hole will 593 00:29:31,320 --> 00:29:34,360 Speaker 1: fall in. Any light that's pointed perfectly tangent to the 594 00:29:34,360 --> 00:29:36,800 Speaker 1: black hole will orbit, and any light that is pointed 595 00:29:36,840 --> 00:29:40,600 Speaker 1: at all out will still escape. It needs some angle 596 00:29:40,640 --> 00:29:43,080 Speaker 1: away from the black hole to escape, but it's still possible. 597 00:29:43,960 --> 00:29:47,960 Speaker 1: So this is the point of no return for almost 598 00:29:47,960 --> 00:29:50,240 Speaker 1: like for for light in a way, Yeah, as you 599 00:29:50,280 --> 00:29:53,160 Speaker 1: get closer, light can still escape if it's pointed further 600 00:29:53,240 --> 00:29:55,880 Speaker 1: and further out, And as you get closer and closer, 601 00:29:55,920 --> 00:29:58,400 Speaker 1: the event horizon is a point at which even light 602 00:29:58,480 --> 00:30:01,440 Speaker 1: pointed straight out from the black hole can no longer 603 00:30:01,520 --> 00:30:03,960 Speaker 1: get out. But the angle for light to escape gets 604 00:30:04,000 --> 00:30:06,320 Speaker 1: smaller and smaller as you get closer and closer to 605 00:30:06,320 --> 00:30:09,560 Speaker 1: the event horizon, until eventually it disappears. All right, So 606 00:30:09,600 --> 00:30:12,000 Speaker 1: then I've satisfied my curiosity. I know what the back 607 00:30:12,040 --> 00:30:14,440 Speaker 1: of my head looks like, finally, And then what happens 608 00:30:14,520 --> 00:30:16,760 Speaker 1: as I go in further than one and a half 609 00:30:16,960 --> 00:30:19,240 Speaker 1: times the radius of the black hole. Well, it's pretty 610 00:30:19,280 --> 00:30:22,560 Speaker 1: cool because this shadow, which has become bigger and bigger, 611 00:30:22,920 --> 00:30:26,400 Speaker 1: grows and grows and grows, and eventually it's even taking 612 00:30:26,440 --> 00:30:28,960 Speaker 1: up more than half of your vision. All right. If 613 00:30:28,960 --> 00:30:31,120 Speaker 1: you imagine yourself sort of at the center of a sphere, 614 00:30:31,160 --> 00:30:33,720 Speaker 1: you can look all around you. The black hole starts 615 00:30:33,720 --> 00:30:35,200 Speaker 1: out at one point of it, and as you get 616 00:30:35,240 --> 00:30:38,080 Speaker 1: closer and closer, it fills up more of that sphere, 617 00:30:38,400 --> 00:30:40,760 Speaker 1: and then it takes up even more than half of 618 00:30:40,800 --> 00:30:44,320 Speaker 1: that sphere. So you're not yet inside the event horizon, 619 00:30:44,640 --> 00:30:47,000 Speaker 1: but the distortion of light makes it look like it's 620 00:30:47,040 --> 00:30:50,960 Speaker 1: sort of eating you. It's like all around you, behind you, 621 00:30:50,960 --> 00:30:53,000 Speaker 1: you can still see out to the universe, but a 622 00:30:53,000 --> 00:30:55,600 Speaker 1: head of you and sort of around you you see 623 00:30:55,640 --> 00:30:59,760 Speaker 1: just the black hole shadow and it's completely pitch black, right, 624 00:30:59,800 --> 00:31:02,760 Speaker 1: like there's you're seeing the black hole, which is completely black. 625 00:31:03,120 --> 00:31:06,000 Speaker 1: There's no stars or anything that's right. It's there's no stars, 626 00:31:06,040 --> 00:31:09,320 Speaker 1: there's nothing there because everything that has fallen into the 627 00:31:09,320 --> 00:31:13,480 Speaker 1: black hole is ahead of you and cannot radiate towards you. Right, 628 00:31:13,800 --> 00:31:16,800 Speaker 1: Nothing that's inside the black hole can shoot anything in 629 00:31:16,840 --> 00:31:19,200 Speaker 1: your direction. The thing that remember is that black holes 630 00:31:19,320 --> 00:31:22,280 Speaker 1: change the shape of space, and inside the black hole, 631 00:31:22,320 --> 00:31:25,840 Speaker 1: space is sort of one directional. Every direction points towards 632 00:31:25,880 --> 00:31:28,440 Speaker 1: the center. And that's sort of beginning to happen now 633 00:31:28,520 --> 00:31:31,240 Speaker 1: as you approach the event horizon. So things that are 634 00:31:31,280 --> 00:31:34,040 Speaker 1: closer to the event horizon than you, they could still 635 00:31:34,080 --> 00:31:36,240 Speaker 1: send you a photon, like if a friend had jumped 636 00:31:36,280 --> 00:31:39,480 Speaker 1: in before you and he was sending flashlight pins back 637 00:31:39,520 --> 00:31:41,760 Speaker 1: to you. You could still see your friend, but the 638 00:31:41,800 --> 00:31:44,640 Speaker 1: black hole itself is not radiating anything else. But if 639 00:31:44,680 --> 00:31:46,800 Speaker 1: you turn around and you look at sort of the 640 00:31:46,880 --> 00:31:49,360 Speaker 1: shrinking window out to the rest of the universe, you 641 00:31:49,400 --> 00:31:52,040 Speaker 1: do see something pretty awesome. Yeah, I guess if it's 642 00:31:52,120 --> 00:31:54,560 Speaker 1: eating you up the blackness, it would be like going 643 00:31:54,600 --> 00:31:57,240 Speaker 1: into a tunnel and the entrance to the tunnel gets 644 00:31:57,240 --> 00:31:59,520 Speaker 1: smaller and smaller. Yes, it's exactly like going into a 645 00:31:59,520 --> 00:32:02,680 Speaker 1: tunnel and that engines gets smaller and smaller. Except when 646 00:32:02,680 --> 00:32:04,520 Speaker 1: you look at from a tunnel, you can only see 647 00:32:04,560 --> 00:32:07,200 Speaker 1: sort of light that shoots straight into the tunnel. But here, 648 00:32:07,200 --> 00:32:09,360 Speaker 1: if you look back where you came from, you can 649 00:32:09,400 --> 00:32:13,360 Speaker 1: see every direction. You can see the whole universe. Advantage 650 00:32:13,360 --> 00:32:15,680 Speaker 1: point from the black hole. You can see from the 651 00:32:15,680 --> 00:32:18,000 Speaker 1: other side of the black hole. Right, it'd be like 652 00:32:18,040 --> 00:32:21,200 Speaker 1: a super powerful fish eye lens that let's you see 653 00:32:21,240 --> 00:32:24,280 Speaker 1: everything in a small view. That's right, because things like 654 00:32:24,360 --> 00:32:25,920 Speaker 1: that are on the other side of the black hole. 655 00:32:26,280 --> 00:32:29,160 Speaker 1: Their light can bend around the black hole and then 656 00:32:29,200 --> 00:32:32,240 Speaker 1: come back and hit your eyeball. So the black hole 657 00:32:32,440 --> 00:32:34,840 Speaker 1: while it's about to eat you, is also still giving 658 00:32:34,880 --> 00:32:37,600 Speaker 1: you like a three hundred and sixty degree view of 659 00:32:37,640 --> 00:32:40,880 Speaker 1: the universe because of all this distortion. You wow. And 660 00:32:40,920 --> 00:32:42,800 Speaker 1: so it's a shrinking view two, right, Like, as I 661 00:32:42,880 --> 00:32:45,520 Speaker 1: moved towards the black hole, the actual radius of the 662 00:32:45,560 --> 00:32:47,760 Speaker 1: actual edge of the black hole, that view is going 663 00:32:47,800 --> 00:32:50,040 Speaker 1: to be shrinking and shrinking and shrinking, and then eventually 664 00:32:50,160 --> 00:32:52,680 Speaker 1: what it disappears and becomes a dot. Yeah, And as 665 00:32:52,720 --> 00:32:55,760 Speaker 1: you move further and further in your window to the 666 00:32:55,840 --> 00:32:59,960 Speaker 1: universe shrinks and eventually becomes a tiny dot. Right, Because 667 00:33:00,040 --> 00:33:01,920 Speaker 1: think about it. If you're at the event horizon and 668 00:33:01,960 --> 00:33:04,959 Speaker 1: you're looking out, the only way for light to escape 669 00:33:05,440 --> 00:33:08,520 Speaker 1: is to go straight out from the event horizon any 670 00:33:08,600 --> 00:33:11,600 Speaker 1: other angle and it's gone, which means if you invert that, 671 00:33:12,000 --> 00:33:14,240 Speaker 1: like coming at any other angle has to have come 672 00:33:14,480 --> 00:33:17,280 Speaker 1: from the black hole. So you're gonna see all black 673 00:33:17,320 --> 00:33:19,960 Speaker 1: except for one dot. And in that dot is a 674 00:33:20,000 --> 00:33:24,200 Speaker 1: picture of the entire universe compressed into a tiny little image. 675 00:33:24,200 --> 00:33:27,000 Speaker 1: Oh man, And then you're inside the black hole. And 676 00:33:27,040 --> 00:33:29,160 Speaker 1: then you're inside the black hole, and take careful notes, 677 00:33:29,240 --> 00:33:31,040 Speaker 1: because I want to hear all about it. All right, 678 00:33:31,080 --> 00:33:34,320 Speaker 1: let's talk about what is actually happening to you as 679 00:33:34,440 --> 00:33:37,960 Speaker 1: you go into the event horizon. But first let's take 680 00:33:37,960 --> 00:33:52,360 Speaker 1: another quick break. All right, Daniel, we are answering the 681 00:33:52,360 --> 00:33:55,800 Speaker 1: deepest questions of the universe right now, which is that 682 00:33:56,200 --> 00:33:59,440 Speaker 1: inside of the event horizon of a black hole, the 683 00:33:59,560 --> 00:34:03,880 Speaker 1: universe has disappeared behind me into a dot. Now I 684 00:34:03,960 --> 00:34:06,840 Speaker 1: am inside of a black hole. What's happening to me? 685 00:34:07,280 --> 00:34:09,520 Speaker 1: So we don't know. We don't know what's inside a 686 00:34:09,560 --> 00:34:11,720 Speaker 1: black hole. We don't know like the structure of matter. 687 00:34:12,239 --> 00:34:15,040 Speaker 1: Is there really a singularity at its core? Is there 688 00:34:15,120 --> 00:34:18,400 Speaker 1: something else weird going on? We're pretty sure a singularity 689 00:34:18,480 --> 00:34:21,080 Speaker 1: can't be right because it's an infinity, and we don't 690 00:34:21,080 --> 00:34:23,960 Speaker 1: think that those things actually exist in nature. That's what 691 00:34:24,000 --> 00:34:27,440 Speaker 1: general relativity predicts. Though general relativity also breaks down at 692 00:34:27,480 --> 00:34:31,040 Speaker 1: the singularity, can't make any real predictions. So we don't know. 693 00:34:31,239 --> 00:34:33,440 Speaker 1: But we could just sort of like assume that general 694 00:34:33,440 --> 00:34:35,640 Speaker 1: relativity is right and talk about what it would be 695 00:34:35,640 --> 00:34:38,960 Speaker 1: like to go into a general relativistic black hole. Well, 696 00:34:39,000 --> 00:34:42,120 Speaker 1: it only breaks down at the very center, right, That's right, 697 00:34:42,239 --> 00:34:44,200 Speaker 1: we think, So you know, up until you get to 698 00:34:44,239 --> 00:34:46,400 Speaker 1: the center, we you can sort of predict what's going 699 00:34:46,480 --> 00:34:48,960 Speaker 1: to happen. Yeah, if general relativity just needs like a 700 00:34:48,960 --> 00:34:52,320 Speaker 1: small modification, if it means like, okay, general relativity is 701 00:34:52,480 --> 00:34:54,800 Speaker 1: right about most of the black holes, just at the core. 702 00:34:54,920 --> 00:34:57,040 Speaker 1: It doesn't quite get the singularity right, and it gets 703 00:34:57,040 --> 00:35:00,200 Speaker 1: like fuzzed out by quantum mechanics. Maybe, but it could 704 00:35:00,239 --> 00:35:02,400 Speaker 1: be that we're totally wrong and that what's inside a 705 00:35:02,400 --> 00:35:04,920 Speaker 1: black hole is completely different and a huge surprise, and 706 00:35:05,280 --> 00:35:08,840 Speaker 1: quantum gravity is something totally unexpected. We just don't know, 707 00:35:09,040 --> 00:35:12,080 Speaker 1: we can't see, which is frustrating. But yeah, we can 708 00:35:12,160 --> 00:35:14,960 Speaker 1: imagine that there's some sort of singularity the core, and 709 00:35:14,960 --> 00:35:16,799 Speaker 1: then we could talk about what it's like then to 710 00:35:16,840 --> 00:35:19,000 Speaker 1: cross the event horizon and dive in. Right, we can 711 00:35:19,080 --> 00:35:22,120 Speaker 1: just assume e signs right. I mean a guy, he's 712 00:35:22,160 --> 00:35:24,440 Speaker 1: gotten some things, right, He had a couple of big hits. 713 00:35:26,120 --> 00:35:28,479 Speaker 1: He's got a pretty good track record. Yeah, so let's 714 00:35:28,520 --> 00:35:30,959 Speaker 1: go with Einstein is right and think about what would 715 00:35:30,960 --> 00:35:33,400 Speaker 1: be like to fall into the black hole. And again, 716 00:35:33,440 --> 00:35:35,480 Speaker 1: the most important thing to remember is that once you're 717 00:35:35,520 --> 00:35:39,680 Speaker 1: inside the black hole, space is now one directional. That 718 00:35:39,800 --> 00:35:42,600 Speaker 1: means it's not just like gravity is pulling you really 719 00:35:42,640 --> 00:35:45,080 Speaker 1: hard and you can't manage to escape. If you could 720 00:35:45,080 --> 00:35:47,239 Speaker 1: just go faster than the speed of light, it means 721 00:35:47,280 --> 00:35:50,880 Speaker 1: that every path moves towards the center of the black hole. 722 00:35:51,360 --> 00:35:54,239 Speaker 1: It's weird to think about space being one directional, but 723 00:35:54,400 --> 00:35:56,759 Speaker 1: think about the way you think about time time very 724 00:35:56,840 --> 00:35:59,959 Speaker 1: naturally think of as one directional. Outside a black hole, 725 00:36:00,280 --> 00:36:03,680 Speaker 1: time is one directional, moves forwards. Inside a black hole, 726 00:36:03,920 --> 00:36:07,520 Speaker 1: space is one directional and moves towards the center. Right, 727 00:36:07,600 --> 00:36:10,080 Speaker 1: But that's the ending is only because you can't go 728 00:36:10,160 --> 00:36:11,960 Speaker 1: faster than the speed of light. If you could go 729 00:36:12,040 --> 00:36:15,000 Speaker 1: faster than the speed of light, you could sort of 730 00:36:15,160 --> 00:36:17,399 Speaker 1: come out of that space. Right. Oh man, It's like 731 00:36:17,920 --> 00:36:21,160 Speaker 1: relativity says you can't escape a black hole and that 732 00:36:21,280 --> 00:36:23,000 Speaker 1: you can't go fast in the speed of light. So 733 00:36:23,080 --> 00:36:26,080 Speaker 1: what would happen if you believed relativity about one thing 734 00:36:26,200 --> 00:36:29,040 Speaker 1: but ignored it about the other thing. I'm not sure 735 00:36:29,239 --> 00:36:31,880 Speaker 1: that would sort of break the fundamental assumption of relativity. 736 00:36:32,760 --> 00:36:36,480 Speaker 1: You would break into thine. All right, Well, I guess 737 00:36:36,560 --> 00:36:39,000 Speaker 1: one thing that's interesting to note is what happens when 738 00:36:39,000 --> 00:36:43,160 Speaker 1: you actually cross the event horizon, Like when you step 739 00:36:43,360 --> 00:36:47,520 Speaker 1: through that point where light can escape. You know, what 740 00:36:47,680 --> 00:36:50,520 Speaker 1: actually happens to me as I go in. Yeah, And 741 00:36:50,520 --> 00:36:53,280 Speaker 1: the surprising thing is if you've picked a large black 742 00:36:53,320 --> 00:36:55,239 Speaker 1: hole where the tidal forces are not going to pull 743 00:36:55,280 --> 00:36:58,400 Speaker 1: you apart, the event horizon is not a special place. 744 00:36:58,480 --> 00:37:00,959 Speaker 1: It's not like there's a fire our wall, or there's 745 00:37:00,960 --> 00:37:04,080 Speaker 1: a gate, or there's dragons or anything right there. It's 746 00:37:04,120 --> 00:37:07,000 Speaker 1: just the point at which light can no longer escape. 747 00:37:07,040 --> 00:37:09,799 Speaker 1: And so your view the universe continues to shrink, and 748 00:37:09,840 --> 00:37:12,759 Speaker 1: you see more and more blackness around you. And that's 749 00:37:12,800 --> 00:37:16,200 Speaker 1: because every path for you, every future direction of yours, 750 00:37:16,360 --> 00:37:18,880 Speaker 1: is towards the center of the black hole, which of 751 00:37:18,920 --> 00:37:22,040 Speaker 1: course isn't emitting anything and looks black. So that's the 752 00:37:22,080 --> 00:37:24,800 Speaker 1: only thing that happens as you cross the event horizon. 753 00:37:25,080 --> 00:37:28,640 Speaker 1: No fireworks, no craziness, just sort of a ceiling of 754 00:37:28,719 --> 00:37:32,160 Speaker 1: your fate. And so then what I would experience is 755 00:37:32,239 --> 00:37:37,960 Speaker 1: just pure darkness. Right according to general relativity, I wouldn't 756 00:37:38,000 --> 00:37:40,840 Speaker 1: see any flashes of light or Matthew McConaughey and a 757 00:37:41,280 --> 00:37:45,240 Speaker 1: you know, premidal kind of space talking to his daughter. 758 00:37:45,760 --> 00:37:48,600 Speaker 1: Depends on if you believe in the power of love rhead, Yeah, 759 00:37:48,640 --> 00:37:53,920 Speaker 1: the fifth dimension. Yeah, to like, what according to general alativity, 760 00:37:53,960 --> 00:37:55,799 Speaker 1: what would I see if anything, would I just see 761 00:37:56,280 --> 00:37:59,719 Speaker 1: stuff continuing to fall into the black hole or what? 762 00:38:00,000 --> 00:38:02,359 Speaker 1: You can't see anything that's in front of you, right, 763 00:38:02,440 --> 00:38:05,040 Speaker 1: because even if stuff has fallen into the black hole 764 00:38:05,120 --> 00:38:07,840 Speaker 1: before you, it's ahead of you and it can't emit 765 00:38:07,920 --> 00:38:11,360 Speaker 1: light in your direction, so you just see blackness ahead 766 00:38:11,360 --> 00:38:14,200 Speaker 1: of you. The only light you could see while you're 767 00:38:14,239 --> 00:38:17,319 Speaker 1: inside the black hole is from things behind you. If 768 00:38:17,360 --> 00:38:19,600 Speaker 1: you're not traveling at the speed of light, then someone 769 00:38:19,719 --> 00:38:22,760 Speaker 1: outside the black hole can still be shooting a laser 770 00:38:22,880 --> 00:38:25,279 Speaker 1: at you that could catch up to you in that 771 00:38:25,360 --> 00:38:28,919 Speaker 1: remaining little tunnel from the outside universe, so you still 772 00:38:29,000 --> 00:38:32,640 Speaker 1: can't see a little dot. Otherwise, all around you is 773 00:38:32,719 --> 00:38:35,759 Speaker 1: just the blackness, a view of the singularity. But that's 774 00:38:35,760 --> 00:38:39,120 Speaker 1: assuming that your brain still works. Right. We talked about 775 00:38:39,120 --> 00:38:42,520 Speaker 1: spaghetification and the tidal forces tearing you apart, but we 776 00:38:42,560 --> 00:38:45,120 Speaker 1: don't even know if your mind, if your brain could work, 777 00:38:45,200 --> 00:38:48,919 Speaker 1: if space becomes one directional, because you know, your brain 778 00:38:48,960 --> 00:38:52,640 Speaker 1: relies on nervous signals, which go forwards and backwards and 779 00:38:52,719 --> 00:38:55,800 Speaker 1: sideways and all around, and the space is one directional, 780 00:38:55,960 --> 00:38:59,239 Speaker 1: could your blood even pump, could your nerves even fire? Right? 781 00:38:59,239 --> 00:39:01,200 Speaker 1: You couldn't have a thought that goes from the front 782 00:39:01,200 --> 00:39:05,040 Speaker 1: of your head to the back of your head, right, exactly, exactly, 783 00:39:05,080 --> 00:39:08,120 Speaker 1: Nothing can move further from the center of the black 784 00:39:08,120 --> 00:39:10,640 Speaker 1: hole because space is just one directional and so it's 785 00:39:10,640 --> 00:39:12,960 Speaker 1: hard to imagine how your body could be configured in 786 00:39:12,960 --> 00:39:15,359 Speaker 1: a way that you would actually even survive. What would 787 00:39:15,400 --> 00:39:19,160 Speaker 1: my body hold together? Even? Technically, yes, right, technically, yes, 788 00:39:19,200 --> 00:39:22,640 Speaker 1: the gravitational title forces near the edge of the event horizon, 789 00:39:22,680 --> 00:39:24,720 Speaker 1: a big black hole would not be enough to tear 790 00:39:24,800 --> 00:39:28,239 Speaker 1: you apart, so it wouldn't pull you into pieces. But 791 00:39:28,280 --> 00:39:30,480 Speaker 1: I don't think you could function very well. I mean, 792 00:39:30,640 --> 00:39:33,239 Speaker 1: your body would have to be reorganized in a way 793 00:39:33,280 --> 00:39:35,960 Speaker 1: so that things just flow in one direction. And so 794 00:39:36,040 --> 00:39:38,560 Speaker 1: you know, like if your blood is getting pumped away 795 00:39:38,560 --> 00:39:40,920 Speaker 1: from your heart, it's never returning to your heart, And 796 00:39:40,960 --> 00:39:43,200 Speaker 1: that doesn't sound like the recipe for a long life. 797 00:39:43,239 --> 00:39:45,520 Speaker 1: Well what if I was just thinking, like, could be 798 00:39:45,920 --> 00:39:48,120 Speaker 1: blood go from your heart to the back of your head? 799 00:39:48,200 --> 00:39:51,600 Speaker 1: Still if your head moves faster than the blood, like 800 00:39:51,680 --> 00:39:53,959 Speaker 1: you could you still have circulation that way? Like? Could 801 00:39:54,239 --> 00:39:56,359 Speaker 1: parts of my body accelerate more than the other parts, 802 00:39:56,400 --> 00:39:58,080 Speaker 1: which means they do go to the back of my head? 803 00:39:58,200 --> 00:40:00,960 Speaker 1: I think that your motion here would be ondly dominated 804 00:40:00,960 --> 00:40:03,560 Speaker 1: by the gravitational forces of the black hole, which would 805 00:40:03,560 --> 00:40:06,480 Speaker 1: swamp everything else. And so I think practically it would 806 00:40:06,480 --> 00:40:08,719 Speaker 1: be impossible to counter that and be like, you know, 807 00:40:09,000 --> 00:40:13,160 Speaker 1: taking a jump on a super supermassive planet is basically impossible. 808 00:40:13,160 --> 00:40:15,880 Speaker 1: And here we're talking about gravitational forces, which, even though 809 00:40:15,920 --> 00:40:17,839 Speaker 1: they're not strong enough to pull you apart yet, are 810 00:40:17,880 --> 00:40:21,120 Speaker 1: still very very strong. And you have nothing to push against, right, 811 00:40:21,160 --> 00:40:23,520 Speaker 1: so how are you going to accelerate your head relative 812 00:40:23,560 --> 00:40:25,160 Speaker 1: to the rest of your body. Well, it'd be like, 813 00:40:25,239 --> 00:40:27,880 Speaker 1: you know, in a super heavy planet, it's hard to 814 00:40:27,960 --> 00:40:30,800 Speaker 1: jump from the surface, But if I'm falling towards a 815 00:40:30,840 --> 00:40:34,120 Speaker 1: giant planet, you could still jump off of the inside 816 00:40:34,160 --> 00:40:36,240 Speaker 1: of your spacehip. Yeah. I suppose if you brought something 817 00:40:36,280 --> 00:40:41,000 Speaker 1: along to push against, then you could relatively change your 818 00:40:41,040 --> 00:40:44,960 Speaker 1: acceleration compared to that object. So you bring like a 819 00:40:45,040 --> 00:40:47,200 Speaker 1: huge bag of bananas and you start throwing them into 820 00:40:47,239 --> 00:40:49,879 Speaker 1: the center of the black hole, then you would change 821 00:40:49,880 --> 00:40:53,239 Speaker 1: your acceleration relative to those things. Yeah, so you could 822 00:40:53,280 --> 00:40:56,600 Speaker 1: maybe still have thoughts as you go in if each 823 00:40:56,600 --> 00:41:00,080 Speaker 1: of your little blood molecules throws tiny bananas and just 824 00:41:00,160 --> 00:41:02,840 Speaker 1: the right direction, then they could continue to park because 825 00:41:03,000 --> 00:41:05,400 Speaker 1: that the idea. Then you'd be glad you ate a 826 00:41:05,400 --> 00:41:08,800 Speaker 1: bunch of bananas before you went in. We've just proved it, folks. 827 00:41:08,960 --> 00:41:12,600 Speaker 1: Bananas will save you inside a black hole. They do 828 00:41:12,719 --> 00:41:16,439 Speaker 1: help you think. Alright, So, um, I would not see 829 00:41:16,480 --> 00:41:19,440 Speaker 1: a lot of interesting things, but maybe I would experience 830 00:41:19,640 --> 00:41:23,040 Speaker 1: something different, you know, like how would you you said 831 00:41:23,200 --> 00:41:26,040 Speaker 1: I might discover the secrets of the universe inside? Would 832 00:41:26,080 --> 00:41:28,759 Speaker 1: I see them, feel them or what I need to 833 00:41:28,840 --> 00:41:31,120 Speaker 1: like bring in an experiment with me. Yeah, well, we 834 00:41:31,160 --> 00:41:33,120 Speaker 1: don't know, because we don't know what you would see. 835 00:41:33,360 --> 00:41:35,239 Speaker 1: You can imagine, you know, what would it be like 836 00:41:35,360 --> 00:41:39,800 Speaker 1: under various scenarios, like if the singularity is real? Well, unfortunately, 837 00:41:39,800 --> 00:41:41,880 Speaker 1: there's no way you survive getting that close. I mean, 838 00:41:41,920 --> 00:41:44,279 Speaker 1: we talked about picking a black hole that's big enough 839 00:41:44,320 --> 00:41:47,319 Speaker 1: to cross the event horizon. But definitely, at some point 840 00:41:47,320 --> 00:41:49,600 Speaker 1: if you get close enough to a singularity, that title 841 00:41:49,640 --> 00:41:52,880 Speaker 1: forces will shred you and so you just cannot survive. 842 00:41:53,200 --> 00:41:55,880 Speaker 1: But imagine then you had some like super duper strong 843 00:41:56,000 --> 00:41:58,480 Speaker 1: probe that was strong enough to resist that sort of 844 00:41:58,520 --> 00:42:01,640 Speaker 1: crushing force and it could get closer. Well, it doesn't 845 00:42:01,640 --> 00:42:04,040 Speaker 1: really matter because the closer you get to singularity, there's 846 00:42:04,040 --> 00:42:07,000 Speaker 1: always more singularity ahead of you, or the singularity is 847 00:42:07,040 --> 00:42:09,840 Speaker 1: a point of infinite density, so you can't be like 848 00:42:10,000 --> 00:42:12,839 Speaker 1: in it. You can't be past some of it. There's 849 00:42:12,880 --> 00:42:15,919 Speaker 1: always space between you and it, and that space gets 850 00:42:15,960 --> 00:42:18,640 Speaker 1: smaller and smaller and smaller, sort of like Zeno's paradox, 851 00:42:18,800 --> 00:42:21,120 Speaker 1: and the gravitational force gets greater and greater and greater 852 00:42:21,160 --> 00:42:24,160 Speaker 1: until it grows to infinity. But you can't like be 853 00:42:24,480 --> 00:42:26,759 Speaker 1: inside of it or in part of it. It's a 854 00:42:26,760 --> 00:42:30,440 Speaker 1: tiny infinitesimal dot. You'ld only just see blackness ahead of 855 00:42:30,520 --> 00:42:34,360 Speaker 1: you unless quantum mechanics is right, and that singularity isn't 856 00:42:34,440 --> 00:42:37,400 Speaker 1: actually infinite. If it exists in some sort of finite 857 00:42:37,440 --> 00:42:40,920 Speaker 1: space it's like fuzzed over by the Heisenberg uncertainty principle, 858 00:42:41,160 --> 00:42:43,200 Speaker 1: and it's a little bit larger, then it might be 859 00:42:43,239 --> 00:42:45,520 Speaker 1: possible to like interact with that in some way, or 860 00:42:45,560 --> 00:42:48,839 Speaker 1: to see it like talking to other parts of the singularity. Well, 861 00:42:48,880 --> 00:42:52,400 Speaker 1: but even if it was fuzzy in the middle, it 862 00:42:52,440 --> 00:42:54,640 Speaker 1: would still tear you apart at some point, right, it 863 00:42:54,640 --> 00:42:57,000 Speaker 1: would tear you apart before you got anywhere close enough 864 00:42:57,000 --> 00:42:59,120 Speaker 1: to do any physics experiments. But you know, if you 865 00:42:59,200 --> 00:43:01,960 Speaker 1: had some really powerful probe, they could get even closer 866 00:43:02,400 --> 00:43:06,960 Speaker 1: than because the quantum singularity might have some actual spatial extent. 867 00:43:07,200 --> 00:43:09,080 Speaker 1: There might be as small window in there for you 868 00:43:09,120 --> 00:43:11,480 Speaker 1: to do some experiments and actually measure it. But I 869 00:43:11,520 --> 00:43:13,920 Speaker 1: think even before then, it would be fascinating just to 870 00:43:14,040 --> 00:43:16,480 Speaker 1: map out the gravity as a function of the radius. 871 00:43:16,480 --> 00:43:19,400 Speaker 1: See like how does the gravitational intensity change or the 872 00:43:19,440 --> 00:43:22,319 Speaker 1: curvature space change as you get closer and closer to 873 00:43:22,320 --> 00:43:24,880 Speaker 1: the black hole center. That could have some surprises. You 874 00:43:24,880 --> 00:43:27,080 Speaker 1: could like measure the gravity in your hands as opposed 875 00:43:27,080 --> 00:43:29,280 Speaker 1: to the gravity your feet, and that might tell you 876 00:43:29,760 --> 00:43:33,879 Speaker 1: whether or not general relativity is working. Yeah, they're doing 877 00:43:33,920 --> 00:43:36,359 Speaker 1: lots of really cool tests of general relativity, and right now, 878 00:43:36,400 --> 00:43:39,120 Speaker 1: from the outside of black holes, they're watching gas swirl 879 00:43:39,120 --> 00:43:42,040 Speaker 1: and they're asking, does it swirl at the velocity we expect? 880 00:43:42,200 --> 00:43:44,800 Speaker 1: And they're using that essentially to measure the gravitational force 881 00:43:44,920 --> 00:43:47,080 Speaker 1: just past the edge of the black hole, because they 882 00:43:47,120 --> 00:43:48,719 Speaker 1: can't measure it on the inside, which is what they 883 00:43:48,719 --> 00:43:51,040 Speaker 1: would actually love to do. So if you're inside the 884 00:43:51,040 --> 00:43:54,279 Speaker 1: black hole, you can measure those forces of gravity, and 885 00:43:54,280 --> 00:43:56,400 Speaker 1: then you could understand something about what's happening at the 886 00:43:56,440 --> 00:43:59,400 Speaker 1: center just from the gravitational twisting and the tweaking of 887 00:43:59,440 --> 00:44:02,480 Speaker 1: the gravitation forces inside the black hole, you can see like, 888 00:44:02,640 --> 00:44:05,080 Speaker 1: is its spinning? Maybe the singularity is a ring and 889 00:44:05,080 --> 00:44:07,440 Speaker 1: it's actually spinning, or maybe it's just the dot. So 890 00:44:07,480 --> 00:44:09,920 Speaker 1: you could learn something about its structure by taking more 891 00:44:09,960 --> 00:44:12,920 Speaker 1: detailed measurements of the gravitational force as a function of 892 00:44:12,960 --> 00:44:15,680 Speaker 1: the distance from the center. Now, Daniel, would that be 893 00:44:15,719 --> 00:44:19,520 Speaker 1: worth it for you to learn that and never come back, 894 00:44:19,920 --> 00:44:22,440 Speaker 1: because I mean it doesn't sound like you know, the 895 00:44:22,520 --> 00:44:25,200 Speaker 1: universe would reveal, so you would just sort of confirmed 896 00:44:25,280 --> 00:44:27,960 Speaker 1: this one part of general relativity. Would that be worth 897 00:44:27,960 --> 00:44:29,880 Speaker 1: it for you? Or there could be a surprise. Right, 898 00:44:29,960 --> 00:44:32,040 Speaker 1: this is just two ideas humans have had, and we 899 00:44:32,080 --> 00:44:34,800 Speaker 1: don't think either of them is right. Was waiting inside 900 00:44:34,800 --> 00:44:37,440 Speaker 1: a black hole could be something totally different. It could 901 00:44:37,480 --> 00:44:39,759 Speaker 1: be a portal to another place in the universe, right, 902 00:44:39,800 --> 00:44:43,719 Speaker 1: a wormhole? It could be something completely surprising that unexpected. 903 00:44:43,760 --> 00:44:46,239 Speaker 1: I mean, think about how much of a surprise relativity 904 00:44:46,440 --> 00:44:49,480 Speaker 1: was or quantum mechanics, and now we're talking about something 905 00:44:49,520 --> 00:44:52,360 Speaker 1: which fuses and changes both of them, and so that 906 00:44:52,360 --> 00:44:54,600 Speaker 1: could be a surprise on the same scale or even 907 00:44:54,680 --> 00:44:58,200 Speaker 1: grander than the intellectual leap required to absorb those and 908 00:44:58,239 --> 00:45:01,160 Speaker 1: so yeah, I'm thirsty for that kind of realization. Sign 909 00:45:01,200 --> 00:45:03,680 Speaker 1: me up right. Well, but you wouldn't be able to 910 00:45:03,680 --> 00:45:06,000 Speaker 1: tell anyone, right because you're inside of the black hole. 911 00:45:06,120 --> 00:45:08,360 Speaker 1: But I would know you would be the only human 912 00:45:08,640 --> 00:45:12,040 Speaker 1: not to know this information and you wouldn't be able 913 00:45:12,080 --> 00:45:14,400 Speaker 1: to tell anyone. Would you still want to know if 914 00:45:14,440 --> 00:45:16,800 Speaker 1: you couldn't tell anyone, Well, since nobody's ever going to 915 00:45:16,880 --> 00:45:19,359 Speaker 1: call my bluff, I can confidently say yes, I would 916 00:45:19,400 --> 00:45:22,120 Speaker 1: want to know, because for me, physics isn't about like 917 00:45:22,480 --> 00:45:24,880 Speaker 1: finding it out and writing the paper. It's about knowing. 918 00:45:24,920 --> 00:45:27,840 Speaker 1: It's about that moment when you're asking nature a question 919 00:45:28,160 --> 00:45:31,560 Speaker 1: and forcing nature to reveal the answer, to extracting some 920 00:45:31,600 --> 00:45:34,480 Speaker 1: piece of information about the universe and just knowing it 921 00:45:34,520 --> 00:45:38,239 Speaker 1: because remember, science is about people's individual curiosity and this 922 00:45:38,320 --> 00:45:43,400 Speaker 1: is mine. All right, Well, it sounds like it's possible 923 00:45:43,440 --> 00:45:45,840 Speaker 1: to go into a black hole and discover some secrets 924 00:45:45,840 --> 00:45:48,799 Speaker 1: of the universe and actually survive, and it would be 925 00:45:48,960 --> 00:45:53,120 Speaker 1: pretty interesting and pretty mind and light bending to do it. Yeah, 926 00:45:53,160 --> 00:45:55,160 Speaker 1: I think that's something that surprises a lot of people 927 00:45:55,520 --> 00:45:57,040 Speaker 1: is that as you fall into the black hole is 928 00:45:57,120 --> 00:45:59,239 Speaker 1: sort of like nothing there. I mean, you get torn 929 00:45:59,239 --> 00:46:01,880 Speaker 1: apart by the ay, but there's no like threshold of 930 00:46:01,920 --> 00:46:04,880 Speaker 1: the event horizons, no trumpets that play, and you just 931 00:46:04,920 --> 00:46:07,800 Speaker 1: sort of fall right on in. Now, it's a different 932 00:46:07,840 --> 00:46:10,520 Speaker 1: story for people who are watching you jump into a 933 00:46:10,520 --> 00:46:13,600 Speaker 1: black hole. There's all sorts of weird relativistic effects there 934 00:46:13,600 --> 00:46:16,239 Speaker 1: as they see your time slowing down, even though for 935 00:46:16,280 --> 00:46:18,759 Speaker 1: you you can just fall right into the black hole 936 00:46:19,040 --> 00:46:23,120 Speaker 1: without noticing any effects on your clock. Wow, so it 937 00:46:23,120 --> 00:46:26,359 Speaker 1: would be a pretty smooth fall until it tears your 938 00:46:26,400 --> 00:46:28,360 Speaker 1: part inside of it. Yes, it would be pretty smooth 939 00:46:28,400 --> 00:46:31,279 Speaker 1: fall until you get torn into shreds. Better at your 940 00:46:31,320 --> 00:46:34,359 Speaker 1: spaghetti before you get to that point, then that's right. 941 00:46:34,560 --> 00:46:36,560 Speaker 1: How do you review that on Yelp? Would have been 942 00:46:36,640 --> 00:46:40,360 Speaker 1: five stars but got shredded and got turned into dinner 943 00:46:40,800 --> 00:46:44,640 Speaker 1: for the black hole? All right? Well, um, I think 944 00:46:44,719 --> 00:46:47,160 Speaker 1: it's you know, a part of a great exercise of 945 00:46:47,560 --> 00:46:51,719 Speaker 1: human evolution to imagine and to wonder what would be 946 00:46:51,800 --> 00:46:54,600 Speaker 1: like to do these crazy things in the universe. Absolutely, 947 00:46:54,719 --> 00:46:58,000 Speaker 1: and these are fun mind experiments because they sharpen our ideas. 948 00:46:58,040 --> 00:47:00,399 Speaker 1: They make us think what would it actually be. Let's 949 00:47:00,440 --> 00:47:03,840 Speaker 1: do the calculation. Let's think about what would happen to 950 00:47:03,920 --> 00:47:06,960 Speaker 1: somebody who jumped into a black hole. And hey, maybe 951 00:47:07,080 --> 00:47:10,000 Speaker 1: someday somebody's bluff will be called and they will actually 952 00:47:10,040 --> 00:47:12,360 Speaker 1: be transported to the edge of the event horizon and 953 00:47:12,520 --> 00:47:15,719 Speaker 1: encouraged to dive in to learn the answers some of 954 00:47:15,800 --> 00:47:18,720 Speaker 1: these deep questions about physics of the universe. And by somebody, 955 00:47:18,800 --> 00:47:21,000 Speaker 1: we mean you, Daniel, You're going to be the first one. 956 00:47:21,120 --> 00:47:23,920 Speaker 1: Because he said it on the record, We're throwing you in. 957 00:47:24,600 --> 00:47:27,279 Speaker 1: That's right. This is a legal statement right here. I 958 00:47:27,400 --> 00:47:30,040 Speaker 1: am bound by these statements. All right, Well, we hope 959 00:47:30,080 --> 00:47:33,120 Speaker 1: you enjoyed that little field trip inside of a black hole. 960 00:47:33,160 --> 00:47:35,359 Speaker 1: I hope you packed enough snacks. Thanks for joining us, 961 00:47:35,800 --> 00:47:45,680 Speaker 1: see you next time. Thanks for listening, and remember that 962 00:47:45,840 --> 00:47:48,560 Speaker 1: Daniel and Jorge Explain the Universe is a production of 963 00:47:48,680 --> 00:47:52,040 Speaker 1: I Heart Radio. For more podcast for my Heart Radio, 964 00:47:52,200 --> 00:47:55,720 Speaker 1: visit the I Heart Radio app, Apple Podcasts, or wherever 965 00:47:55,880 --> 00:48:03,120 Speaker 1: you listen to your favorite shows. No