WEBVTT - What is a black hole eclipse? 0:00:08.440 --> 0:00:12.399 Hey or hey, are you a fan of Pokemon cards? Yeah, 0:00:12.400 --> 0:00:14.000 a little bit. My son used to play them. My 0:00:14.040 --> 0:00:17.439 son also, though I think he mostly collected and traded them. 0:00:17.480 --> 0:00:20.680 I don't think he ever actually played with them. M Yeah, 0:00:20.680 --> 0:00:22.279 I think that happens a lot, although I did play 0:00:22.360 --> 0:00:24.640 with him for a few times. It's a pretty interesting game. 0:00:24.680 --> 0:00:26.080 And do you have any of those cards with like 0:00:26.239 --> 0:00:29.040 super awesome powers? Yeah? They have pretty good names, like 0:00:29.240 --> 0:00:32.959 flame body. My personal favorite is the card that can 0:00:32.960 --> 0:00:37.120 do a black hole eclipse. Although that sounds kind of 0:00:37.159 --> 0:00:39.959 like a random combination of words from physics that they 0:00:40.000 --> 0:00:42.640 just kind of put together. I think that's the same 0:00:42.640 --> 0:00:46.000 way that physicist name things though. Ah, so you admitted 0:00:46.560 --> 0:00:49.720 it's all random. We just type the words into an 0:00:49.720 --> 0:00:52.320 online random number generator and that's where we go with. 0:00:53.200 --> 0:00:55.800 They have a bunch of physicists working for Pokemon, just 0:00:55.840 --> 0:00:57.680 in case that the whole physics scurity doesn't work out. 0:00:57.720 --> 0:01:00.880 Do you have a promising career working for That's always 0:01:00.880 --> 0:01:18.600 been my backup plane. Hi am Poor Hamming, cartoonist and 0:01:18.600 --> 0:01:21.840 the co author of Frequently Asked Questions about the Universe. Hi. 0:01:22.000 --> 0:01:24.720 I'm Daniel. I'm a particle physicist and a professor at 0:01:24.800 --> 0:01:27.600 UC Irvine, and I probably have hundreds of dollars worth 0:01:27.600 --> 0:01:30.520 of Pokemon cards somewhere in the closets of my home. 0:01:31.200 --> 0:01:33.679 Are they wrapped an individual plastic though, to keep him 0:01:33.680 --> 0:01:36.640 in mint condition? Otherwise I'm not sure they're worth that much. 0:01:38.840 --> 0:01:41.839 They have definitely been prepared as an investment in the future. 0:01:42.080 --> 0:01:44.840 That's how you plan to pay for your son's college education. 0:01:44.959 --> 0:01:46.680 I think that's how my son plans to pay for 0:01:46.720 --> 0:01:49.240 his retirement. Yeah. Wow, if it's worth that much, maybe 0:01:49.240 --> 0:01:51.880 they should conveniently disappear from your closet. Only if I 0:01:51.880 --> 0:01:53.960 could find them in my son's closet. I think that's 0:01:54.000 --> 0:01:57.720 part of his security plan. Yes, it's such a mess, 0:01:57.760 --> 0:02:00.080 it's like a black hole in itself, but anyway is 0:02:00.080 --> 0:02:02.840 Welcome to our podcast Daniel and Jorge Explain the Universe, 0:02:02.880 --> 0:02:05.640 a production of I Heart Radio in which we try 0:02:05.680 --> 0:02:08.800 to clean up a mess that is this universe and 0:02:08.919 --> 0:02:12.040 all of its crazy, confusing glory. We dig right into 0:02:12.120 --> 0:02:15.000 everything that doesn't make sense, everything that should make sense, 0:02:15.040 --> 0:02:18.000 and things that might never make sense. We talked about 0:02:18.000 --> 0:02:21.040 the biggest questions at the heart of philosophical inquiries about 0:02:21.040 --> 0:02:24.240 the nature of our universe, and we talk about practical 0:02:24.280 --> 0:02:27.400 stuff like how things around you actually work. We dive 0:02:27.440 --> 0:02:30.000 into all of these questions and try to explain to 0:02:30.040 --> 0:02:33.680 you what scientists do and do not know about them 0:02:33.720 --> 0:02:36.560 because it is a pretty fun universe full of interesting 0:02:36.639 --> 0:02:39.600 and amazing characters, not all of them with superpowers like 0:02:39.639 --> 0:02:42.880 Pokemon characters, but there are a lot of interesting objects 0:02:42.919 --> 0:02:46.680 out there in the universe with the seemingly superpowerful powers. 0:02:46.880 --> 0:02:49.000 And it is our belief, or at least our hope, 0:02:49.080 --> 0:02:52.320 that the universe does make sense, that it's following some 0:02:52.360 --> 0:02:54.560 set of rules, and that if we dig into it 0:02:54.639 --> 0:02:56.919 hard enough, if we use our brains, if we come 0:02:57.000 --> 0:02:59.720 up with a clever set of experiments, we can figure 0:02:59.720 --> 0:03:01.720 out what those rules are. That in the end, there 0:03:01.800 --> 0:03:04.320 isn't magic in the universe, but that everything can be 0:03:04.400 --> 0:03:07.800 explained with science. I'm not sure the same can be 0:03:07.840 --> 0:03:10.880 said about Pokemon powers. What are you saying that Pokemon 0:03:11.080 --> 0:03:15.160 aren't physically accurate there? How do you know, Daniel, I'm 0:03:15.200 --> 0:03:17.440 not sure we have to suspend disbelief. But I did 0:03:17.520 --> 0:03:20.120 do a bit of research into what the black hole 0:03:20.200 --> 0:03:23.600 eclipse move is for the Pokemon character, and here's the 0:03:23.639 --> 0:03:27.880 official description. The user gathers dark energy with its Z 0:03:28.120 --> 0:03:33.600 power and forms a black hole that sucks the opponent up. Interesting. 0:03:33.680 --> 0:03:35.839 That seems like a bit of a dangerous weapon there, 0:03:35.840 --> 0:03:38.680 because once you start the black hole, I guess, can 0:03:38.720 --> 0:03:40.880 you turn it off? Or is there a Z switch 0:03:40.960 --> 0:03:44.360 for it? It depends on what your Z power can do. 0:03:44.800 --> 0:03:47.400 If you can tap into dark energy and expand or 0:03:47.440 --> 0:03:50.360 contract space, then hey, you have got a lot of options. Well, 0:03:50.360 --> 0:03:52.800 there is the idea that maybe there are unknown forces 0:03:52.800 --> 0:03:55.400 in the universe we haven't discovered. Maybe the Z force 0:03:55.520 --> 0:03:57.520 is one of them. And if I discovered an unknown 0:03:57.560 --> 0:03:59.640 force and called it the Z force, would you be 0:03:59.640 --> 0:04:03.080 impress with my naming? I guess I mean to try 0:04:03.120 --> 0:04:05.160 out any of the other letters in the alphabet first. 0:04:05.240 --> 0:04:07.440 The Z force makes me think it's related to the 0:04:07.560 --> 0:04:10.680 Z boson, which we know is a very feeble boson. 0:04:10.760 --> 0:04:14.320 It carries the weak force, probably not capable of making 0:04:14.400 --> 0:04:17.840 black holes. So there is technically a Z force in 0:04:17.880 --> 0:04:20.880 the universe right now, like the force made by a 0:04:21.000 --> 0:04:24.600 Z boson is technically a Z force. Yeah, that's right, 0:04:24.640 --> 0:04:26.360 though I'm not sure you can use it to gather 0:04:26.440 --> 0:04:29.520 any dark energy and throw your opponent into a black hole. 0:04:29.640 --> 0:04:32.039 But hey, best to luck to you. How do you know, Daniel, 0:04:32.520 --> 0:04:34.560 have you tried? I haven't tried, but I'm going to 0:04:34.640 --> 0:04:38.080 write a grand proposal to the Pokemon Science Foundation to 0:04:38.120 --> 0:04:40.360 see if I can get some funds to try it out. Yeah, 0:04:40.360 --> 0:04:42.400 the PSF, they fund a lot of work out here. 0:04:42.640 --> 0:04:45.000 But technically, in a multiverse, isn't it possible that there 0:04:45.040 --> 0:04:48.160 are Pokemon characters out there? I mean, if you say 0:04:48.200 --> 0:04:50.840 in a multiverse, isn't it possible that I suppose almost 0:04:50.839 --> 0:04:54.200 anything is possible because in some theories of the multiverse 0:04:54.279 --> 0:04:57.719 there are universes with other laws of physics, which basically 0:04:57.760 --> 0:05:01.600 allows almost anything to happen. Oh, there you go, It's official. 0:05:01.640 --> 0:05:06.120 Here in the podcast, Daniel thinks Pokemon are real. They 0:05:06.160 --> 0:05:09.240 are a really good investment in my son's feature and 0:05:09.279 --> 0:05:12.440 a real possibility. But it is interesting. How did you 0:05:12.520 --> 0:05:17.039 end up googling Pokemon powers online? What's going on there? Daniel? No, 0:05:17.160 --> 0:05:20.520 I was googling black hole eclipse, of course, in preparation 0:05:20.600 --> 0:05:23.520 for today's episode. And the top hit was not black 0:05:23.560 --> 0:05:26.920 holes or eclipses or anything scientific. The top like ten 0:05:27.040 --> 0:05:29.479 hits were all about Pokemon. I think that tells you 0:05:29.480 --> 0:05:32.599 a little bit about the priority of the Internet. But 0:05:32.680 --> 0:05:34.200 it is interesting. What do you think is going on 0:05:34.240 --> 0:05:37.799 inside the head of those Pokemon creators, artists and writers 0:05:37.839 --> 0:05:39.440 when they come up with these things, Right, because they 0:05:39.760 --> 0:05:41.800 used to work dark energy, they must know a little 0:05:41.839 --> 0:05:44.440 bit of something about physics. Well, you know, I think 0:05:44.480 --> 0:05:47.680 as they make more and more Pokemon characters, that have 0:05:47.720 --> 0:05:49.920 to be more and more powerful or as my son 0:05:49.960 --> 0:05:53.160 would say, totally opie, and so they want to come 0:05:53.200 --> 0:05:55.720 up with something really dramatics and they're really crazy. And 0:05:55.760 --> 0:05:57.719 I guess black holes are on the top of the 0:05:57.760 --> 0:06:00.920 list of like aspirational powers to whether you can make 0:06:00.960 --> 0:06:03.520 a black hole using dark energy. You know, we don't 0:06:03.520 --> 0:06:05.920 really know what dark energy is at all. We just 0:06:06.000 --> 0:06:09.960 know that it's accelerating the expansion of space and separating 0:06:09.960 --> 0:06:12.200 the black holes from each other. So if anything, it's 0:06:12.279 --> 0:06:14.680 keeping black holes from getting bigger. Well, I guess my 0:06:14.760 --> 0:06:17.920 question is what kind of energy car does that attack us? 0:06:18.040 --> 0:06:21.320 Dark energy cars? Is there such a thing? If there 0:06:21.360 --> 0:06:24.680 isn't such a thing, then there should be Pokemon Science Foundation, 0:06:24.839 --> 0:06:27.800 please fund that. There should be a science type Pokemon. 0:06:28.279 --> 0:06:31.159 You know, there's like a water type, fire type. There 0:06:31.160 --> 0:06:33.520 should be like a physics type. We have exhausted my 0:06:33.600 --> 0:06:35.960 knowledge of Pokemon. Now I have nothing else to contribute 0:06:35.960 --> 0:06:39.279 to this conversation. I went a little opie on you 0:06:40.080 --> 0:06:42.960 all overpowered you. But it is an interesting name to 0:06:42.960 --> 0:06:45.040 give a power to a fictional character. But it kind 0:06:45.040 --> 0:06:48.240 of makes you think, is it actually possible for something 0:06:48.480 --> 0:06:50.880 like that to happen? And we know that crazy things 0:06:50.880 --> 0:06:53.800 happen out there in the universe. We are constantly surprised 0:06:53.800 --> 0:06:56.800 by what's going on in the hearts of other galaxies 0:06:56.839 --> 0:06:59.719 and even in between galaxies, and so you should never 0:07:00.040 --> 0:07:02.120 say never, and so do they. On the podcast, we'll 0:07:02.160 --> 0:07:10.760 be asking the question can a black hole be eclipsed? 0:07:11.120 --> 0:07:13.120 And can you use it to suck up your enemies? 0:07:13.880 --> 0:07:17.680 Is the question that a lot of kids are probably asking, 0:07:17.760 --> 0:07:20.360 and maybe some physicists. Please, if you do have the 0:07:20.480 --> 0:07:23.600 z power to manipulate dark energy to create black holes, 0:07:23.880 --> 0:07:25.960 don't do it. You might win the battle and then 0:07:26.120 --> 0:07:28.800 destroy the planet. Although they'll give you a Nobel prize, though, 0:07:28.800 --> 0:07:31.360 wouldn't they in the five minutes between the creation of 0:07:31.400 --> 0:07:33.400 your black hole and the destruction of the Earth. I'm 0:07:33.400 --> 0:07:36.560 not sure the Swedish Academy acts that fast. I don't know. 0:07:36.640 --> 0:07:39.520 I've seen you talk, Daniel, you will sacrifice anything for science. 0:07:39.680 --> 0:07:41.480 If you have such a Z power, create a black 0:07:41.520 --> 0:07:44.000 hole out in the depths of space where we can 0:07:44.040 --> 0:07:46.200 study it. Please. I guess if you have that kind 0:07:46.200 --> 0:07:48.600 of power, you can afford to go out into space. Right. 0:07:48.640 --> 0:07:50.640 Maybe you also have the ex power and the why power? 0:07:50.840 --> 0:07:53.640 Right right? Although I thought the why power was physicist 0:07:53.680 --> 0:07:56.240 superpower or is that the philosophers? It's the four year 0:07:56.240 --> 0:08:01.280 olds power? Why? Why? Why? Why? Yes, it's an interminable 0:08:01.320 --> 0:08:03.880 source of energy. But it is an interesting question, and 0:08:03.920 --> 0:08:06.320 as usual, we were wondering how many people out there 0:08:06.360 --> 0:08:09.040 had thought about this question whether a black hole can 0:08:09.080 --> 0:08:12.280 be eclipsed. So thanks very much to everybody who volunteers 0:08:12.320 --> 0:08:15.480 to answer these questions in advance. Were very grateful to you, 0:08:15.520 --> 0:08:17.760 and we hope that you enjoy hearing your voice on 0:08:17.800 --> 0:08:20.160 the podcast. If any of you out there would like 0:08:20.200 --> 0:08:22.720 to participate, please don't be shy. Right to me two 0:08:22.800 --> 0:08:25.680 questions at Daniel and Jorne dot com. So think about 0:08:25.720 --> 0:08:28.120 it for a second. Do you think a black hole 0:08:28.160 --> 0:08:31.280 can be eclipsed? Here's what people had to say. Assuming 0:08:31.280 --> 0:08:37.560 the definition of eclipse is for one body to obscure 0:08:37.600 --> 0:08:42.120 another body from a given a vantage point. Um sure, 0:08:42.200 --> 0:08:44.280 I don't see why a black hole could not be 0:08:44.320 --> 0:08:48.880 eclipsed by another celestial body. I thought that might be 0:08:48.920 --> 0:08:51.720 how we discovered them or something. I guess a black 0:08:51.760 --> 0:08:54.760 hole can be eclipsed. I mean normally in eclipse is 0:08:54.800 --> 0:08:58.800 when the light from something is blocked by something else 0:08:58.800 --> 0:09:01.800 in space. So as a black hole doesn't have any 0:09:01.880 --> 0:09:04.000 light emitting from it, I wouldn't have thought it could 0:09:04.040 --> 0:09:06.839 be eclipsed as such. But I guess if you get 0:09:06.880 --> 0:09:09.439 something massive enough in front of it, in between us 0:09:09.520 --> 0:09:12.840 and it, then it would be eclipsed. I don't see 0:09:12.880 --> 0:09:17.800 why not. As long as something subjectively larger than them 0:09:17.880 --> 0:09:22.439 is between them and the observer, it would eclipse. The 0:09:22.480 --> 0:09:25.480 black hole might have to be subjectively larger than the 0:09:25.600 --> 0:09:29.000 disc around it to really have a shot at it. Well, 0:09:29.040 --> 0:09:31.520 the concept of eclipse, the way I understand it, is 0:09:31.559 --> 0:09:37.720 that light from a star as blocked from Earth's view 0:09:37.840 --> 0:09:43.480 by an intervening body. Certain's black holes do not emit light. 0:09:44.200 --> 0:09:47.880 I don't think they can be eclipsed. I don't think 0:09:47.960 --> 0:09:52.199 so because I believe when black holes mass passes before 0:09:52.200 --> 0:09:55.280 a gravity you see lensing effects. And I don't know 0:09:55.960 --> 0:09:58.679 I've ever heard of one being eclipsed before. Yes, I 0:09:58.760 --> 0:10:00.679 think they can do if they're is a planet or 0:10:00.760 --> 0:10:04.360 star closer to us in the right alignment with the 0:10:06.120 --> 0:10:08.800 black hole. Yes, I think they can be eclipsed. Yes, 0:10:08.880 --> 0:10:11.160 I think it can in the sense that is coming 0:10:11.200 --> 0:10:14.280 in front of something else. Um. But like instead of 0:10:14.320 --> 0:10:17.040 blocking the light like the moon we block the Sun's light, 0:10:17.800 --> 0:10:20.120 I think it would just absorb the light of whatever 0:10:20.400 --> 0:10:23.600 is behind it. But um, it could also have this 0:10:24.240 --> 0:10:27.920 gravitational lensing effect where the light of the objects that 0:10:27.920 --> 0:10:31.400 aren't directly behind it kind of get curved um due 0:10:31.440 --> 0:10:34.240 to the black hole, and we perceive it um in 0:10:34.280 --> 0:10:36.920 that way. So that's kind of the black hole version 0:10:36.920 --> 0:10:40.880 of an eclipse. Yes, they can be eclips Let's say 0:10:41.000 --> 0:10:43.240 instead of our son, it will be a black hole 0:10:44.440 --> 0:10:49.280 like we heard at a podcast Danielle and Horhan. We 0:10:49.360 --> 0:10:51.520 would need to be at a safe distance from it, 0:10:51.920 --> 0:10:56.040 and we can safely go around it. And if we 0:10:56.120 --> 0:10:59.800 have the moon that would be between us and the 0:11:00.040 --> 0:11:03.040 that hole. I don't see why not the more collectives 0:11:03.120 --> 0:11:07.080 the site of the black hole. All right, A wide 0:11:07.160 --> 0:11:10.000 range of answers here. Somebody said, why not always a 0:11:10.040 --> 0:11:12.600 good answer? Am I talking about physics of the universe. 0:11:13.160 --> 0:11:17.760 Why not, there's the multiverse, Doctor Strange says, anything can 0:11:17.800 --> 0:11:19.520 happen in the multiverse. Or do you think they were 0:11:19.520 --> 0:11:21.760 taking it as a proposal, like, hey, should we make 0:11:21.800 --> 0:11:24.880 a black hole eclipse? Why not? Let's go right now. 0:11:25.200 --> 0:11:26.839 I'm up for it. I guess it made me think, 0:11:27.040 --> 0:11:29.240 what do you mean by eclipse, like in terms of 0:11:29.280 --> 0:11:34.000 attention or in terms of blocking its light? But it's 0:11:34.000 --> 0:11:36.360 a black hole. Yeah, it's a good question. And I 0:11:36.440 --> 0:11:39.680 noticed that there was like two different interpretations of eclipse there, 0:11:39.800 --> 0:11:43.520 one the black hole being eclipsed like something blocking light 0:11:43.600 --> 0:11:46.600 from a black hole, and the other the black hole 0:11:46.720 --> 0:11:50.000 doing the eclipsing, like passing in front of something else 0:11:50.080 --> 0:11:54.040 that makes light. So there's sort of two possibilities there. Interesting, 0:11:54.200 --> 0:11:56.079 and I guess we're going to argue about which one 0:11:56.160 --> 0:11:58.719 is more correct. For the next hour, we're going to 0:11:58.800 --> 0:12:01.080 talk about both possibility. At least. Of course, we're gonna 0:12:01.080 --> 0:12:03.640 do the quantum superposition. We're gonna do the forwards and 0:12:03.720 --> 0:12:06.840 the backwards. All right, Well, let's start with the basics here, Daniel, 0:12:06.880 --> 0:12:08.600 What is a black hole? First of all, so we 0:12:08.640 --> 0:12:11.280 don't really know what a black hole is in the 0:12:11.360 --> 0:12:15.120 actual universe, and we don't actually even really know if 0:12:15.200 --> 0:12:19.160 black holes exist. As described by the theory, we have 0:12:19.280 --> 0:12:23.040 this concept in general relativity that if you get enough 0:12:23.120 --> 0:12:27.760 stuff together, it's gravity will overcome any sort of internal strength, 0:12:28.080 --> 0:12:31.480 any power of the material to resist being compressed. The 0:12:31.520 --> 0:12:33.880 gravity will eventually get so strong that it will just 0:12:33.920 --> 0:12:36.559 squeeze it down further and further and further, and as 0:12:36.559 --> 0:12:38.920 it gets denser and denser, and the gravity gets stronger 0:12:38.960 --> 0:12:41.840 and stronger, and you get this crazy runaway effect, and 0:12:42.040 --> 0:12:46.559 where gravity essentially becomes infinitely strong in a tiny little dot, 0:12:46.760 --> 0:12:49.800 this singularity at the point in space where you have 0:12:50.160 --> 0:12:54.360 not infinite mass but infinite density, because gravity is compressed 0:12:54.440 --> 0:12:57.600 some blob of stuff down to a very very small distance, 0:12:57.760 --> 0:13:00.320 and because it's compressed it so far and means that 0:13:00.360 --> 0:13:02.160 you can get pretty close to a lot of mass, 0:13:02.240 --> 0:13:05.280 which means the gravity even nearby it would be very strong, 0:13:05.520 --> 0:13:08.440 so strong that we think that it curves space so 0:13:08.520 --> 0:13:11.520 much that light cannot even escape it. So if these 0:13:11.520 --> 0:13:14.000 things are real, if they're out there in the universe, 0:13:14.040 --> 0:13:16.720 then whatever falls into this black hole you will never 0:13:16.800 --> 0:13:20.280 see again because light from it cannot escape. Would you 0:13:20.320 --> 0:13:23.440 say it's an actual hole in space, Daniel. And you know, 0:13:23.480 --> 0:13:25.160 if you define a hole is something that you can 0:13:25.240 --> 0:13:28.120 fall into, then it's technically it is. That's why it's 0:13:28.120 --> 0:13:30.560 called a whole. Right, if you accept the general relativity 0:13:30.600 --> 0:13:32.640 view of it, it's kind of a hole because it 0:13:32.679 --> 0:13:35.720 makes a portion of space that's cut off from the 0:13:35.760 --> 0:13:39.040 rest of the universe. It's like a little sub universe, 0:13:39.080 --> 0:13:41.600 and once you enter that sub universe, you really are 0:13:41.679 --> 0:13:43.800 cut off from the rest of it. I mean inside 0:13:43.800 --> 0:13:46.040 the black hole, you can still see the rest of 0:13:46.040 --> 0:13:48.120 the universe. Light from the rest of the universe can 0:13:48.160 --> 0:13:50.280 still reach you, so you can see out from it, 0:13:50.440 --> 0:13:53.760 but nobody can see into it, right, So in that sense, 0:13:53.840 --> 0:13:56.800 it's a hole in space, right, Although that's assuming your 0:13:56.800 --> 0:13:58.800 eyeball is still in one piece when you're inside of 0:13:58.800 --> 0:14:01.920 a black hole, right, Yeah, precisely, assuming that you survive 0:14:02.040 --> 0:14:04.520 long enough to look out into the black hole. And 0:14:04.559 --> 0:14:06.920 black holes can come in all sorts of sizes. You 0:14:06.960 --> 0:14:09.040 can make a black hole in theory out of a 0:14:09.080 --> 0:14:11.800 pretty small amount of mass as long as you squeeze 0:14:11.840 --> 0:14:14.680 it down to a small enough radius. You can also 0:14:14.720 --> 0:14:17.720 make black holes out of enormous masses. Some of the 0:14:17.760 --> 0:14:19.880 things out there that we think are black holes probably 0:14:19.920 --> 0:14:23.800 have millions or billion times the mass of our sun. 0:14:24.000 --> 0:14:26.440 Those black holes are really really big, and if you 0:14:26.520 --> 0:14:30.040 fall into one of those, the gravity at the outskirts 0:14:30.080 --> 0:14:33.000 of the black hole is not actually that strong. I mean, 0:14:33.000 --> 0:14:35.200 it's strong enough to suck up light, but it's not 0:14:35.280 --> 0:14:38.040 so strong to like tear you apart to spaghettify you. 0:14:38.360 --> 0:14:41.000 So you might be able to survive the very first 0:14:41.080 --> 0:14:44.360 few moments of falling into a really really big black hole, 0:14:44.680 --> 0:14:47.000 and then you can take it selfie, although you can 0:14:47.080 --> 0:14:49.720 never send that selfie to anyone. Hey, selfies are just 0:14:49.800 --> 0:14:54.240 for yourself, right, that's why they're called selfie. Ironically, that 0:14:54.360 --> 0:14:57.920 is the opposite purpose of a selfie. They should be 0:14:57.920 --> 0:15:00.320 called that everyone else's. But it is interesting what you 0:15:00.320 --> 0:15:02.760 said about the black holes having a size, because it's 0:15:02.760 --> 0:15:04.440 it's kind of into it's like a hole in space, 0:15:04.480 --> 0:15:07.280 but it does have volume, right, Like, it does occupy 0:15:07.720 --> 0:15:11.120 three dimensional space. In fact, it's a sphere in space, right, 0:15:11.360 --> 0:15:13.560 I mean, it's just kind of distort space, but it 0:15:13.640 --> 0:15:16.760 does sort of occupy a certain you know, length, width 0:15:16.800 --> 0:15:19.480 and in height. Yeah, if you say black hole, you're 0:15:19.480 --> 0:15:22.080 probably imagining like a circle on the ground a two 0:15:22.120 --> 0:15:25.200 dimensional object that things can fall into and disappear, like 0:15:25.320 --> 0:15:27.960 in cartoon shows. But as you say, they are three 0:15:27.960 --> 0:15:32.000 dimensional objects. So the simplest black hole, one that isn't spinning, 0:15:32.000 --> 0:15:34.520 would be a perfect sphere, and you can fall into 0:15:34.560 --> 0:15:37.440 it from any direction. If you're looking at a perfect 0:15:37.480 --> 0:15:40.280 sphere that's perfectly black, it's always just gonna look like 0:15:40.320 --> 0:15:42.760 a circle to you because there's no texture to it, 0:15:42.840 --> 0:15:45.520 so you can't sort of like tell how much curvature 0:15:45.560 --> 0:15:47.880 it has. But actually, if you look at a black hole, 0:15:47.920 --> 0:15:50.960 you don't even really just see a black sphere. It 0:15:51.000 --> 0:15:54.320 looks even bigger than it actually is because the paths 0:15:54.360 --> 0:15:56.840 of light around the black hole are really really weird. 0:15:56.920 --> 0:15:58.720 Like if somebody was very close to the edge of 0:15:58.720 --> 0:16:00.720 the black hole on the back side of it and 0:16:00.760 --> 0:16:03.080 turned on a flashlight, you could see it from the 0:16:03.120 --> 0:16:05.360 other side of the black hole because the light from 0:16:05.360 --> 0:16:08.400 that flashlight would curve around the black hole, bent by 0:16:08.400 --> 0:16:11.880 its incredible gravity to your eyeballs. So if you're near 0:16:11.920 --> 0:16:13.920 a black hole, if you're just looking at it, you 0:16:13.960 --> 0:16:17.320 can actually see the entire surface of the black hole 0:16:17.640 --> 0:16:19.240 right in front of you. You can see the front 0:16:19.520 --> 0:16:22.640 and the back right though it just looks black, right, Yeah, 0:16:22.640 --> 0:16:25.160 it just looks like a bigger black circle than it 0:16:25.240 --> 0:16:27.840 actually is. It's like puffed up, yeah, like puffed up 0:16:27.880 --> 0:16:30.760 because in the vicinity of a black hole, space is curved, 0:16:30.760 --> 0:16:33.480 and when space is curved, you can't trust your eyes 0:16:33.520 --> 0:16:36.080 to be just showing you what he's there. You're seeing 0:16:36.200 --> 0:16:38.360 now an image of what is there, and then image 0:16:38.360 --> 0:16:40.280 can be distorted, just like if you're in a fun 0:16:40.320 --> 0:16:43.160 house mirror and it's not flat and what you're seeing 0:16:43.320 --> 0:16:46.400 isn't reality the same as true. Near a black hole, 0:16:46.720 --> 0:16:49.240 light doesn't travel in straight lines anymore, and so what 0:16:49.360 --> 0:16:52.320 you see is an image is generated by the physical 0:16:52.360 --> 0:16:54.960 stuff that's there, but it's not a fully faithful image 0:16:55.120 --> 0:16:57.360 of what's actually out there. It's a little bit mind 0:16:57.400 --> 0:16:59.720 bending because a black hole is sort of like a sphere. 0:17:00.000 --> 0:17:02.080 It sort of has the surface, but it's not really 0:17:02.080 --> 0:17:04.520 a surface because it's not solid. It's just kind of 0:17:04.520 --> 0:17:06.080 like the edge of the hole. So it's like a 0:17:06.119 --> 0:17:08.480 three dimensional edge of a hole is the surface of 0:17:08.480 --> 0:17:10.640 a black hole. Yeah, And what you call the edge 0:17:10.640 --> 0:17:13.159 of a black hole is a little bit arbitrary. We 0:17:13.320 --> 0:17:16.920 usually use the location of the event horizon, the point 0:17:16.920 --> 0:17:19.960 past which light and particles and nothing can escape, and 0:17:20.160 --> 0:17:22.160 to mark the edge of the black hole. But there's 0:17:22.200 --> 0:17:25.000 nothing there at the edge. It's sort of like a 0:17:25.040 --> 0:17:28.199 calculation we do to say where it is, and you 0:17:28.200 --> 0:17:31.879 can't actually even tell where the event horizon is until 0:17:31.920 --> 0:17:34.359 the end of the universe. The definition of the event 0:17:34.359 --> 0:17:38.639 horizon is any particle past this point never escapes. But 0:17:38.680 --> 0:17:41.280 it's not always easy to tell exactly what can escape 0:17:41.320 --> 0:17:44.359 and what can't, and so you can't actually know in 0:17:44.440 --> 0:17:46.840 any moment where the event horizon is. You have to 0:17:46.880 --> 0:17:48.720 sort of like wait to the end of time and 0:17:48.720 --> 0:17:51.399 then say, particles that got closer than this, none of 0:17:51.440 --> 0:17:54.640 them escaped. So here was the event horizon, right, because 0:17:54.680 --> 0:17:57.359 we actually like fall into the hole that sort of 0:17:57.440 --> 0:18:00.600 almost sort of never happens, right, because time gets distorted 0:18:00.640 --> 0:18:02.800 around the black hole that it basically as you said, 0:18:02.840 --> 0:18:06.080 happens never. Yeah. And also there's just like nothing there 0:18:06.119 --> 0:18:08.080 at the event horizon. It's not like a surface you 0:18:08.160 --> 0:18:10.400 land on. It's just a point of no return. It's 0:18:10.400 --> 0:18:12.240 like if you got into your car and you drove 0:18:12.280 --> 0:18:14.200 too far away from a gas station so that you 0:18:14.240 --> 0:18:16.359 didn't have enough gas to get to the next gas station. 0:18:16.480 --> 0:18:18.800 Nothing would happen at that moment when you had gone 0:18:18.800 --> 0:18:21.120 too far. You would only realize it later, like, oops, 0:18:21.440 --> 0:18:24.120 we forgot to get gas and now we're stranded. The 0:18:24.160 --> 0:18:26.760 moment when you crossed that threshold where you now too 0:18:26.800 --> 0:18:28.600 far away from the nearest gas station you don't have 0:18:28.680 --> 0:18:31.720 enough fuel to get one, no warning light necessarily goes off. 0:18:31.760 --> 0:18:33.439 And the same is true for the event horizon. It 0:18:33.480 --> 0:18:36.520 just feels like the rest of space. You pass through it, 0:18:36.600 --> 0:18:40.199 and unbeknownst to you, you are now wrapped inside the 0:18:40.200 --> 0:18:43.359 black hole. Right, Although you know, if you're flying that 0:18:43.400 --> 0:18:45.439 close to a black hole, you can't claim not to 0:18:45.440 --> 0:18:47.480 have seen it because it's going to look pretty big 0:18:47.520 --> 0:18:50.400 to flying close to a black hole. Right. Oh yeah, 0:18:50.400 --> 0:18:53.080 it's definitely irresponsible space flight in the same way like 0:18:53.240 --> 0:18:55.240 you should know if you're about to run out of gas, 0:18:55.240 --> 0:18:57.000 and somebody should be paying attention to it, or at 0:18:57.040 --> 0:18:59.720 least there should be a warning alarm on your space ship. 0:19:00.760 --> 0:19:05.080 Black hole ahead, turn right, use your Z powers now. 0:19:05.280 --> 0:19:07.560 But as you said, it doesn't occupy space because it 0:19:07.640 --> 0:19:10.800 is an object. It doesn't have less solid surface, and 0:19:10.840 --> 0:19:13.800 it's also like moving around in space, right, black holes 0:19:13.840 --> 0:19:16.720 can move around in space. Even though their holes in space, 0:19:17.000 --> 0:19:20.240 they can move around in space. It's like a moving hole. Yeah, 0:19:20.320 --> 0:19:22.360 well they are a thing, right, They are made out 0:19:22.400 --> 0:19:25.160 of mass, and so like everything else, they have a location, 0:19:25.200 --> 0:19:27.159 and then they can have a velocity. But you know, 0:19:27.200 --> 0:19:29.439 the velocity of the black hole is relative, just like 0:19:29.520 --> 0:19:32.120 everything else. If you are moving towards a black hole, 0:19:32.160 --> 0:19:34.840 you could also say the black hole is moving towards you. 0:19:35.320 --> 0:19:37.960 There is no difference in the physics of the universe 0:19:38.119 --> 0:19:41.280 in those two pictures, and so black holes, like everything else, 0:19:41.320 --> 0:19:44.040 can have location and velocity. Yeah, there could be one 0:19:44.080 --> 0:19:47.879 moving towards us right now, right almost definitely, because we 0:19:47.920 --> 0:19:50.240 know that there's a supermassive black hole at the heart 0:19:50.240 --> 0:19:52.840 of the Andromeda Galaxy which is coming for us. Right 0:19:52.880 --> 0:19:55.320 The Andromeda Galaxy is going to collide with the Milky 0:19:55.320 --> 0:19:57.359 Way in a few billion years, and so the black 0:19:57.400 --> 0:20:00.639 holes at the heart of each galaxy are moving towards 0:20:00.680 --> 0:20:03.920 the other galaxy. So, yeah, black holes are headed our way. 0:20:04.040 --> 0:20:07.479 Better get working on that Z force, Daniel. We're counting 0:20:07.480 --> 0:20:09.720