WEBVTT - Black Holes, Part 3: The Future 0:00:03.040 --> 0:00:05.840 Welcome to Stuff to Blow Your Mind from how Stuff 0:00:05.840 --> 0:00:14.760 Works dot com. Hey, welcome to Stuff to Blow your Mind. 0:00:14.840 --> 0:00:17.400 My name is Robert Lamb and I'm Joe McCormick, and 0:00:17.520 --> 0:00:19.960 you are here. We're here. It's part three of our 0:00:20.000 --> 0:00:24.200 exploration of black holes. Now. I think this all came about, Robert, 0:00:24.280 --> 0:00:26.640 because you went to the World Science Festival and saw 0:00:26.680 --> 0:00:29.760 a great presentation on black holes. In't that right? Yes, 0:00:29.800 --> 0:00:33.120 it was called Darkness Visible, Shedding New Light on black Holes. 0:00:33.520 --> 0:00:37.519 It's a tremendous presentation. It's available on YouTube for your viewing, 0:00:37.680 --> 0:00:39.199 and I'll make sure that there is a link to 0:00:39.240 --> 0:00:41.200 it on the landing page for this episode. It's Stuff 0:00:41.200 --> 0:00:43.279 to Blow your Mind dot com. Now, it's funny. This 0:00:43.320 --> 0:00:45.159 is gonna be our third episode in a row on 0:00:45.240 --> 0:00:47.200 black holes, and this will be the last one for now. 0:00:47.320 --> 0:00:50.080 We will probably revisit the subject again in the future, 0:00:50.360 --> 0:00:52.920 because even in three whole episodes, there's no way to 0:00:52.960 --> 0:00:55.640 even come close to exploring all of the interesting stuff 0:00:56.000 --> 0:00:58.640 about black holes. But we're here for part three. In 0:00:58.680 --> 0:01:02.400 the first part, we explored the sort of the idea 0:01:02.560 --> 0:01:05.920 history of black holes, like where they came from conceptually 0:01:06.000 --> 0:01:09.399 before anybody had ever looked up and seen one. And 0:01:09.440 --> 0:01:11.600 then in the second episode we tried to talk about 0:01:11.640 --> 0:01:14.640 ways of inferring the physical existence of black holes, not 0:01:14.720 --> 0:01:18.160 just the theoretical framework underlying them, but how we can 0:01:18.680 --> 0:01:21.319 detect them out there in the universe. And then in 0:01:21.360 --> 0:01:24.240 today's episode, we wanted to sort of like, uh, just 0:01:24.280 --> 0:01:27.880 do a grab bag of interesting outstanding questions about black 0:01:27.920 --> 0:01:31.280 holes or thought experiments involving what we know about black 0:01:31.280 --> 0:01:33.920 holes today. Yeah, then we'll get into some sort of 0:01:33.920 --> 0:01:37.480 sci fi ideas here as well for sure, which, of course, 0:01:37.560 --> 0:01:42.600 uh brings us back to the topic of cinematic betrayals 0:01:42.680 --> 0:01:45.280 of black holes. We talked a little bit about the 0:01:45.560 --> 0:01:48.680 Disney movie The Black Hole. In the previous episodes we 0:01:48.720 --> 0:01:53.640 talked about Interstellar and how Interstellar is is actually a 0:01:53.640 --> 0:01:57.120 pretty good um scientific model to look at as far 0:01:57.160 --> 0:02:00.480 as depictions of black holes in cinema. But then of 0:02:00.480 --> 0:02:05.080 course there's Event Horizon, Oh is there? This was the 0:02:05.480 --> 0:02:08.639 Paul W. S Anderson film, arguably in my mind, the 0:02:08.880 --> 0:02:13.360 best um Paul W. S Anderson film. What would be 0:02:13.360 --> 0:02:16.079 the other candidate for the best Paul W. S Anderson 0:02:16.120 --> 0:02:17.880 film one of the Resident Evils, I guess one of 0:02:17.919 --> 0:02:21.160 the seven or Eight Resident Evils or Mortal Kombat. You 0:02:21.160 --> 0:02:23.040 know you can go with that. That was his film 0:02:23.080 --> 0:02:25.840 prior to Event Horizon. No, I don't want to be mean, 0:02:25.919 --> 0:02:29.040 but to be generous, we could say not this generation's 0:02:29.080 --> 0:02:32.240 most highbrow filmmaker. Not to say that that that you 0:02:32.280 --> 0:02:36.560 and I are purely highbrow of Cinnema enthusiasts. No, we 0:02:36.639 --> 0:02:41.960 love some trash, and boy's Event Horizon some delectable nineties trash. 0:02:42.000 --> 0:02:45.600 It's it's got funny c g I. It's got get 0:02:45.600 --> 0:02:49.040 to the Chopper kind of stuff. It's got a great cast. Actually, 0:02:49.320 --> 0:02:53.560 it's got hilariously bad writing. It's uh yeah, it's solid 0:02:53.560 --> 0:02:56.960 B movie territory. It certainly is in that it has 0:02:57.120 --> 0:02:59.600 uh well, I mean for starters. It's it's certainly not 0:02:59.639 --> 0:03:00.840 a beam of you if when it comes to the 0:03:00.840 --> 0:03:03.640 amount of money that's enter this thing. But in terms 0:03:03.680 --> 0:03:06.359 of of of of looking when you look at it 0:03:06.400 --> 0:03:09.359 as a whole, there are a lot of problems when 0:03:09.400 --> 0:03:11.400 you but when you look at some of the of 0:03:11.480 --> 0:03:14.560 the elements that go into making the film, there are 0:03:14.560 --> 0:03:16.720 a lot of things I like about it. I think 0:03:16.760 --> 0:03:19.880 the ship looks really cool, this ideal leather punk spaceship, yeah, 0:03:20.000 --> 0:03:22.800 I mean it looks like a cathedral. They I like 0:03:22.880 --> 0:03:26.639 how it incorporates some of these, um these these very 0:03:26.639 --> 0:03:30.240 obvious elements from films like the Shining uh you know, 0:03:30.240 --> 0:03:33.120 two thousand and one of Space Odyssey Solaris and brings 0:03:33.120 --> 0:03:35.440 them all to together. I bet you like the soundtrack, 0:03:35.520 --> 0:03:38.000 don't you. Well. I thought I was gonna like the 0:03:38.000 --> 0:03:40.840 soundtrack because it's been a long time since I've seen this, 0:03:40.920 --> 0:03:46.440 like possibly since high school, and I rewatched rewatched it 0:03:46.720 --> 0:03:50.120 before we went into to to record this episode. The 0:03:50.120 --> 0:03:51.720 main thing I was remembering here was that, oh yeah, 0:03:51.800 --> 0:03:56.240 Orbital worked on the soundtrack Orbital of course, or Legends 0:03:56.240 --> 0:04:00.600 of the electronic genre that for instance there the Orbital 0:04:00.640 --> 0:04:04.000 too is a classic, and I recommend everyone who's into 0:04:04.640 --> 0:04:07.200 electronic and ambience you should check it out. They were 0:04:07.240 --> 0:04:10.040 also on the soundtrack of the Paul ws Anderson film 0:04:10.040 --> 0:04:13.640 Mortal Kombat. Yeah, so that that soundtrack was pretty awesome 0:04:13.760 --> 0:04:16.480 back in the day. But you know me, I love 0:04:16.480 --> 0:04:19.880 a good electronic score. So I went back to View 0:04:19.880 --> 0:04:22.960 of the Horizon expecting there to be a lot more Orbital, 0:04:22.960 --> 0:04:27.520 a lot more electronic uh nuance. But the thing is, 0:04:27.560 --> 0:04:31.400 it's not just an orbital score. It's orbital and Michael Common, 0:04:32.040 --> 0:04:36.080 and Michael Common brings the the orchestral stuff into this equation, 0:04:36.200 --> 0:04:39.240 and it really felt like there was far It was 0:04:39.279 --> 0:04:42.960 a far more traditional film score than I really wanted 0:04:42.960 --> 0:04:44.880 to hear. It's one of those beat you over the 0:04:44.920 --> 0:04:48.120 head horror scores, you know, I hope you want some 0:04:48.360 --> 0:04:52.640 was Yeah. Yeah, so it did not really Uh it 0:04:52.680 --> 0:04:55.880 did did not really please me on that level. Um, 0:04:55.920 --> 0:04:57.679 but I you know, I like this. I like the ship, 0:04:57.720 --> 0:05:00.120 I like some of the horror elements, and the cast 0:05:00.200 --> 0:05:02.719 is so good that you can forgive a lot of things, 0:05:02.760 --> 0:05:06.800 like when Sam neil Is is your lead actor, it 0:05:06.839 --> 0:05:09.960 forgives a lot of sins. And he, arguably, I would argue, 0:05:10.360 --> 0:05:14.800 plays the best possible pinhead in this true he essentially 0:05:14.839 --> 0:05:17.919 becomes a cinebyte in this film, and in doing so, 0:05:18.040 --> 0:05:21.920 he's like he's a cut above any other cinematic cinebyte. Yeah. 0:05:22.000 --> 0:05:24.960 You could argue that Event Horizon is a very bad movie, 0:05:25.040 --> 0:05:26.960 but that it might be in a way the best 0:05:27.000 --> 0:05:31.279 Hell raisor sequel. Yeah, yeah, I would agree with that. Now, 0:05:31.360 --> 0:05:32.800 of course, that the harder Why are we talking about 0:05:32.800 --> 0:05:35.880 Event Horizon? As we touched we've discussed already in There's 0:05:35.920 --> 0:05:39.240 a black Hole episodes. The event horizon is the point 0:05:39.279 --> 0:05:44.160 at which light cannot escape the gravity of the singularity. 0:05:44.240 --> 0:05:47.000 It's the point of no return, right, So you've got 0:05:47.000 --> 0:05:50.440 this incredibly dense core at the middle of a black hole. Say, 0:05:50.480 --> 0:05:53.279 if your black hole is the remnant of a collapse star. 0:05:53.640 --> 0:05:55.919 You know, your star goes supernova, blasts a lot of 0:05:55.920 --> 0:05:58.240 its material out into space, and then it's got this 0:05:58.320 --> 0:06:01.359 remnant leftover that's very din It's within what's known as 0:06:01.360 --> 0:06:04.960 short shield radius, and if it's within that radius, it 0:06:04.960 --> 0:06:09.160 will collapse upon itself in this weird process that even 0:06:09.200 --> 0:06:12.000 now we're still trying to understand most fully. It will 0:06:12.040 --> 0:06:14.480 collapse it this way that it looks like it collapses 0:06:14.520 --> 0:06:18.760 towards infinite density, and it creates this sphere around it 0:06:18.839 --> 0:06:22.400 where anything that goes inside the sphere never comes out again. 0:06:22.640 --> 0:06:26.000 It cannot overcome the force of gravity. It just becomes 0:06:26.040 --> 0:06:28.919 part of the black hole. Right. And in the film 0:06:28.960 --> 0:06:32.719 Event Arizon, the essential science the argument that is made 0:06:33.360 --> 0:06:37.320 uh when when Sam Neil's character Like is forced to 0:06:37.400 --> 0:06:40.159 explain this to the crew of a spaceship who apparently 0:06:40.160 --> 0:06:43.960 have no idea how space works. Uh. Apparently the Event 0:06:43.960 --> 0:06:49.279 Horizon spaceship creates an artificial singularity which is then used 0:06:49.320 --> 0:06:53.000 to open a wormhole of some sort. And that's that's 0:06:53.040 --> 0:06:56.760 his about is is? Uh? Is detailed as the explanation 0:06:56.800 --> 0:06:59.359 gets so also they go to Hell? Well, yes, but 0:06:59.480 --> 0:07:02.880 that's that's how they get there through the wormhole, or 0:07:02.920 --> 0:07:05.400 the wormhole goes through Hell. I've done a little vague here. 0:07:05.520 --> 0:07:07.599 So why have we spent so much time talking about 0:07:07.600 --> 0:07:11.200 Event Horizon. Here's why, because I'm going to argue that 0:07:11.240 --> 0:07:15.200 I think a scientifically accurate movie about going to a 0:07:15.200 --> 0:07:17.560 black hole could be scarier than a movie where you 0:07:17.560 --> 0:07:20.360 need to put hell and demons in there. All right, Well, 0:07:20.360 --> 0:07:22.320 that that can be the argument we make during the 0:07:22.360 --> 0:07:25.320 course of this episode for sure. Okay, well, I think 0:07:25.360 --> 0:07:27.240 we should talk about what would be like if you 0:07:27.280 --> 0:07:29.440 want to fall into a black hole. Let's say you 0:07:29.480 --> 0:07:32.160 get a hanker and you're saying, I want to approach 0:07:32.200 --> 0:07:35.240 infinite density. Hey it's two thousand eighteen. Yeah, you know, 0:07:35.280 --> 0:07:38.440 I totally understand that desire. I feel flabby, I feel 0:07:38.480 --> 0:07:41.800 kind of bloated. I'm going for infinite density now, So 0:07:41.960 --> 0:07:43.680 you say I'm going to fall into a black hole. 0:07:43.760 --> 0:07:46.480 You've decided to hop into a spaceship, travel out into 0:07:46.480 --> 0:07:50.880 the universe, and intentionally fly straight into a very big 0:07:50.920 --> 0:07:52.960 black hole. Now, there are a lot of people who 0:07:53.000 --> 0:07:55.480 have written about this subject, trying to imagine what it 0:07:55.520 --> 0:07:58.640 would be like, the subjective experience of approaching a black hole, 0:07:58.960 --> 0:08:02.560 crossing the event her Eisen, and then falling in. Uh there. 0:08:02.600 --> 0:08:04.680 I think Neil de grass Tyson actually has a book 0:08:04.720 --> 0:08:07.080 about it. I haven't read that book, but I've read 0:08:07.120 --> 0:08:10.240 a bunch of stuff about this. Probably the best explanation 0:08:10.280 --> 0:08:12.480 I've read, and one of my main sources here is 0:08:12.520 --> 0:08:16.200 going to be an explanation from the astrophysicist Ethan Siegel, 0:08:16.320 --> 0:08:19.960 who is astrophysicist and a science blogger. He runs the 0:08:20.000 --> 0:08:22.440 Starts with a Bang blog. Do you ever read that, Robert? 0:08:23.120 --> 0:08:26.440 He writes good stuff about astrophysics. Um so, so he's 0:08:26.480 --> 0:08:28.600 got an exploration here that I think is pretty good. 0:08:28.600 --> 0:08:31.760 So he says, Okay, you imagine you're approaching a black hole, 0:08:32.200 --> 0:08:34.400 and if the black hole were the mass of Earth, 0:08:35.000 --> 0:08:37.839 the sphere that you do you'd be approaching would only 0:08:37.840 --> 0:08:41.320 be about one centimeter in radius or about two centimeters wide. 0:08:41.800 --> 0:08:43.760 If the black hole were about the mass of the Sun, 0:08:44.240 --> 0:08:47.640 the sphere would only be about three kilometers in radius 0:08:47.720 --> 0:08:50.960 or about six kilometers wide. So the actual spheres of 0:08:51.000 --> 0:08:53.280 the event horizon that you would see are are much 0:08:53.320 --> 0:08:55.600 smaller than a lot of the other things you'd encounter 0:08:55.600 --> 0:08:57.760 out in the universe. That is, unless you're coming up 0:08:57.800 --> 0:08:59.920 against one of the biggest ones, like say, a super 0:09:00.040 --> 0:09:02.040 massive black hole. The kinds of that are at the 0:09:02.080 --> 0:09:06.480 center of galaxies, So as you approach the black hole 0:09:06.720 --> 0:09:09.719 from a kind of normal orbital distance. One of the 0:09:09.720 --> 0:09:11.760 funny things is that, first of all, you might not 0:09:11.880 --> 0:09:16.400 immediately notice anything strange about the gravity. The gravitational influence 0:09:16.400 --> 0:09:18.640 you would feel would be a lot like approaching or 0:09:18.720 --> 0:09:22.240 orbiting a star of the same mass. And to reiterate, 0:09:22.280 --> 0:09:24.439 if a star the size of our Sun were suddenly 0:09:24.880 --> 0:09:28.040 magically turned into a black hole. Uh and by the way, 0:09:28.040 --> 0:09:30.560 this would not ever happen in point of fact, because 0:09:30.559 --> 0:09:33.040 our son is not massive enough to naturally become a 0:09:33.040 --> 0:09:36.120 black hole. But if you were to buy magic turn 0:09:36.160 --> 0:09:38.760 it into a black hole of the same mass, Earth 0:09:38.800 --> 0:09:42.240 would simply continue orbiting. It wouldn't be immediately sucked in 0:09:42.400 --> 0:09:46.200 or anything. Things would get very weird on Earth but 0:09:46.200 --> 0:09:48.559 but yeah, we would not be sucked into the black hole. Right. 0:09:49.160 --> 0:09:52.360 But once you got closer, then things really do start 0:09:52.400 --> 0:09:55.400 to get weirder, especially when you get very close. So 0:09:55.440 --> 0:09:57.800 as you approach the black hole, first of all, you 0:09:57.800 --> 0:10:00.160 would notice that as you get closer, the black back 0:10:00.200 --> 0:10:05.800 hole gets bigger faster than any normal object would as 0:10:05.920 --> 0:10:08.720 you approached it. So you might have a normal sense 0:10:08.760 --> 0:10:11.120 of Okay, I'm flying towards a planet, or I'm flying 0:10:11.160 --> 0:10:14.400 towards a star. At a certain speed, you can have 0:10:14.440 --> 0:10:17.920 a pretty predictable rate of its expansion to take up 0:10:17.920 --> 0:10:20.760 more and more degrees of your field of view. Right 0:10:21.440 --> 0:10:23.720 as you near a black hole, the black hole actually 0:10:23.720 --> 0:10:28.160 gets bigger faster than any normal object would because rays 0:10:28.240 --> 0:10:30.880 of light beaming towards you passing all around the black 0:10:30.880 --> 0:10:35.360 hole are bent dramatically inward. Now, remember what we'd actually 0:10:35.400 --> 0:10:38.040 be seeing out there is you'd see sort of a 0:10:38.080 --> 0:10:42.120 black disc with light warped around it. Remember the short 0:10:42.160 --> 0:10:45.120 shield radius, the distance from the center of the black 0:10:45.120 --> 0:10:48.480 hole to the event horizon. Uh. The the event horizon, 0:10:48.559 --> 0:10:52.240 of course, is the sphere catastrophe, the point beyond which nothing, 0:10:52.280 --> 0:10:55.920 not even light can escape. And as you approach that sphere. 0:10:56.000 --> 0:10:58.960 More closely, the apparent short shield radius from your point 0:10:58.960 --> 0:11:02.440 of view will grow dramatically. A seagull rights that by 0:11:02.480 --> 0:11:06.280 the time you're about ten schwart shield radii away from 0:11:06.320 --> 0:11:08.400 the black holes, about ten of the radius of the 0:11:08.440 --> 0:11:11.520 black hole away from it, it will appear so big 0:11:11.559 --> 0:11:14.640 that it will blot out your entire forward forward facing 0:11:14.720 --> 0:11:17.480 view right, so if you're looking toward it, it will 0:11:17.520 --> 0:11:21.040 be your entire field of view. A normal object of 0:11:21.080 --> 0:11:24.080 the same size at that distance would only appear to 0:11:24.080 --> 0:11:26.760 be about the size of your fist at an arm's length. 0:11:27.200 --> 0:11:29.800 Then you go deeper and you can reach There are 0:11:29.840 --> 0:11:31.880 several sort of stops along the way. One of the 0:11:31.880 --> 0:11:33.839 stops you would reach along the way is what's known 0:11:33.880 --> 0:11:37.400 as the innermost stable circular orbit, or the I s 0:11:37.440 --> 0:11:40.000 c O. This is sort of the last filling station 0:11:40.080 --> 0:11:42.600 before you head down to the border. The I s 0:11:42.600 --> 0:11:45.320 c O is about one point five times the radius 0:11:45.360 --> 0:11:48.400 of the event horizon, and it's what it sounds like 0:11:48.400 --> 0:11:51.079 based on the name. It's the closest that particles can 0:11:51.200 --> 0:11:54.600 orbit the black hole in a stable circle. Go any 0:11:54.640 --> 0:11:58.600 closer and it's all downhill, pretty much literally. By the 0:11:58.640 --> 0:12:00.520 time you reach the I s c O. If you 0:12:00.559 --> 0:12:03.320 face a black hole, you will see nothing but black 0:12:03.360 --> 0:12:05.559 in the direction of the black hole, and the event 0:12:05.640 --> 0:12:08.160 horizon will appear to take up your your whole field 0:12:08.160 --> 0:12:11.080 of view. But here's the crazy part. You keep going 0:12:11.160 --> 0:12:14.240 down past the I s c OH and of course 0:12:14.280 --> 0:12:16.760 total blackness will still take up your entire field of 0:12:16.800 --> 0:12:19.840 view if you look toward the black hole. But here's 0:12:19.880 --> 0:12:22.960 what happens if you turn around and look away. And 0:12:23.000 --> 0:12:25.240 I'll explore this in a couple of different ways. First, 0:12:25.320 --> 0:12:28.200 a scenario one. This is where you imagine it's only 0:12:28.360 --> 0:12:31.920 you falling in. It's not light or other stuff falling 0:12:31.920 --> 0:12:33.560 in with you. And this is not how it would 0:12:33.559 --> 0:12:37.600 probably really be, just to illustrate the gravitational influences involved. 0:12:37.840 --> 0:12:40.520 If you keep going toward the black hole and you 0:12:40.640 --> 0:12:43.400 turn back and look away from it as you're falling in, 0:12:43.920 --> 0:12:47.000 you will see total darkness begin to creep in from 0:12:47.040 --> 0:12:51.520 every direction as well in the direction you came from. 0:12:51.559 --> 0:12:53.640 So you're looking backward, and you will see what looks 0:12:53.679 --> 0:12:57.800 like a membrane of total darkness closing in all around, 0:12:58.480 --> 0:13:01.439 and your view of the stars the universe will shrink 0:13:01.600 --> 0:13:05.000 down to a circle in the direction opposite of the 0:13:05.000 --> 0:13:07.640 black hole. Just try to imagine that your whole view 0:13:08.160 --> 0:13:11.600 of the universe being bent and crushed down into a 0:13:11.679 --> 0:13:16.080 shrinking circle that's receding behind you rapidly. Well again it 0:13:16.120 --> 0:13:20.800 is so I can't imagine that to a certain extent. Yeah, 0:13:20.880 --> 0:13:24.560 all starlight dies in a shrinking circle. That that's that's 0:13:24.559 --> 0:13:27.640 in your past like that. But at this point it's 0:13:27.640 --> 0:13:30.480 important to remember you have not crossed the event horizon yet, 0:13:30.520 --> 0:13:33.200 you're just approaching it. So at this point, if you 0:13:33.200 --> 0:13:35.079 were to change your mind and say, hey, I want 0:13:35.080 --> 0:13:37.680 to get out of here, uh, there is in principle 0:13:37.760 --> 0:13:40.560 still hope if you have a powerful enough spaceship you 0:13:40.600 --> 0:13:42.800 could turn around. You could pile it back towards that 0:13:42.880 --> 0:13:45.960 shrinking circle of starlight and escape the black hole, at 0:13:46.000 --> 0:13:48.440 least in theory. But it is at this point going 0:13:48.480 --> 0:13:51.000 to be a really powerful uphill climb against the gravity 0:13:51.000 --> 0:13:52.959 of the black hole. But let's say, you know, I 0:13:53.000 --> 0:13:55.079 don't want to escape, I just want to keep falling. 0:13:55.160 --> 0:13:58.600 So that's what you do. Assuming you keep looking towards 0:13:58.640 --> 0:14:01.280 that shrinking circle of are light behind you where you 0:14:01.320 --> 0:14:04.560 came from, it will eventually shrink down to a point 0:14:04.679 --> 0:14:07.840 like light source as you near the boundary, as you 0:14:07.880 --> 0:14:10.559 near the event horizon, and right before you cross the 0:14:10.600 --> 0:14:13.840 event horizon, the light from that point will cycle through 0:14:13.840 --> 0:14:17.479 an array of colors due to what's known as gravitational 0:14:17.559 --> 0:14:20.520 blue shifting, so you'll see red than white, than blue. 0:14:21.080 --> 0:14:23.960 And at this point, all the low frequency radiation in 0:14:23.960 --> 0:14:28.520 the universe, stuff like the cosmic microwave background, which stuff 0:14:28.520 --> 0:14:31.000 which is like microwaves and radio waves, not stuff that's 0:14:31.040 --> 0:14:35.040 normally visible, will shift up because of the blue shift 0:14:35.120 --> 0:14:40.239 of the electromagnetic spectrum. It'll shift up into the visible spectrum, 0:14:40.440 --> 0:14:43.200 and you'll actually be able to see the cosmic microwave 0:14:43.240 --> 0:14:47.520 background as a visible blue with your eyes. Then finally 0:14:48.000 --> 0:14:51.120 you hit the border. Okay, so you crossed the event horizon. 0:14:51.160 --> 0:14:54.200 What do you see in this toy scenario where light 0:14:54.360 --> 0:14:57.080 is not falling in with you, you will see nothing 0:14:57.120 --> 0:15:00.440 at all. You have entered ultimate darkness and this point 0:15:00.480 --> 0:15:04.040 there is no escape, no matter what. So let's say 0:15:04.040 --> 0:15:07.040 you say, no, I changed my mind after I crossed 0:15:07.080 --> 0:15:09.720 the event horizon. I want to pilot my spaceship back 0:15:09.760 --> 0:15:12.400 in the direction I came from. So that should be easy, right, 0:15:12.680 --> 0:15:15.240 You just turn around and you come back in exactly 0:15:15.240 --> 0:15:19.720 the opposite direction. You've been traveling. Too bad, you can't 0:15:19.840 --> 0:15:22.880 do it. If you try, you will discover to your 0:15:22.920 --> 0:15:25.720 great surprise that the direction that used to be the 0:15:25.760 --> 0:15:28.760 direction you came from is now downhill into the center 0:15:28.760 --> 0:15:31.560 of the black hole. And in fact, every direction you 0:15:31.640 --> 0:15:34.000 try to go in is downhill into the center of 0:15:34.000 --> 0:15:37.240 the black hole. It is the perfect pit. It is 0:15:37.280 --> 0:15:40.600 a pit in which the only direction is down. You're 0:15:40.640 --> 0:15:43.760 going into that thing no matter what in any travel 0:15:43.840 --> 0:15:47.240 you do would only speed your travel towards the center 0:15:47.280 --> 0:15:49.760 of the thing. That's kind of mind bending to to 0:15:49.760 --> 0:15:52.800 to think about. But yeah, essentially all all roads lead 0:15:52.800 --> 0:15:55.200 to Rome at this point. The remaining question is how 0:15:55.240 --> 0:15:57.600 long does it take you to get to Rome? Right, 0:15:57.640 --> 0:16:00.320 so you've crossed, you can't go back, how long do 0:16:00.360 --> 0:16:02.960 you fall before you sort of reach the center of 0:16:03.000 --> 0:16:06.240 this thing? Seagull rights that quote as you crossed the 0:16:06.280 --> 0:16:09.840 horizon at the super massive four million solar mass black 0:16:09.880 --> 0:16:13.160 hole at the galactic center, believe it or not. Despite 0:16:13.200 --> 0:16:15.400 the fact that we're talking about an event horizon that 0:16:15.480 --> 0:16:18.960 might be around a light hour in diameter in our 0:16:19.000 --> 0:16:22.840 reference frame, it would only take around twenty seconds to 0:16:22.880 --> 0:16:26.200 reach the singularity once you cross the event horizon. Now, 0:16:26.240 --> 0:16:28.760 remember that first scenario was kind of a toy scenario 0:16:28.800 --> 0:16:31.320 where light is falling is not falling in with you. 0:16:31.440 --> 0:16:33.840 That's just to like see what the gravitational effects are. 0:16:34.640 --> 0:16:38.120 The physics of the effects are on display, But we 0:16:38.200 --> 0:16:41.680 created a kind of unrealistic scenario. So in reality, you 0:16:41.680 --> 0:16:44.760 would probably not be approaching and entering a black hole alone, 0:16:44.800 --> 0:16:47.520 but you'd be approaching and entering along with a huge 0:16:47.640 --> 0:16:50.640 tide of light and radiation. And this would mean that 0:16:50.680 --> 0:16:53.400 in reality, your picture of the universe would not shrink 0:16:53.440 --> 0:16:56.000 to a point behind you as you approached the black hole, 0:16:56.280 --> 0:16:59.040 but would remain a kind of warped division of the 0:16:59.080 --> 0:17:02.920 sky following you down through the darkness after you crossed 0:17:02.960 --> 0:17:05.440 the event horizon, and that light that you would see 0:17:05.440 --> 0:17:08.120 would be the light that's been sucked toward and into 0:17:08.160 --> 0:17:11.880 the event horizon with you. But as as we've been 0:17:11.880 --> 0:17:16.239 talking about before, unless you just assume some kind of 0:17:16.240 --> 0:17:21.119 technological or magical form of invincibility, it's highly possible given 0:17:21.240 --> 0:17:23.240 various factors. There are a lot of different ways that 0:17:23.320 --> 0:17:25.720 a black hole could be but it's highly possible that 0:17:25.760 --> 0:17:27.840 you would die at pretty much every stage of the 0:17:27.880 --> 0:17:31.639 scenario would be describing um for several reasons, one of 0:17:31.720 --> 0:17:36.119 which is what's been classically known as spaghettification. I've certainly 0:17:36.359 --> 0:17:38.719 heard Neil de grass Tyson speak about this. It's one 0:17:38.760 --> 0:17:42.800 of the astrophysicists favorite concepts. Uh So, as you approach 0:17:42.960 --> 0:17:46.879 the center of gravity of smaller classes of black holes, 0:17:47.440 --> 0:17:51.360 title forces would work you up good and title forces 0:17:51.400 --> 0:17:55.119 occur when an object is stretched and deformed because of 0:17:55.160 --> 0:17:59.320 an imbalance of gravitational forces at different parts of the object. 0:17:59.480 --> 0:18:02.639 We've talked before about Jupiter's moon Io. You know, Io 0:18:02.840 --> 0:18:04.760 is one of the most I think it might be 0:18:04.840 --> 0:18:07.640 the most volcanically active object in the Solar System. If 0:18:07.640 --> 0:18:09.440 it's not the most, it's one of the most. It's 0:18:09.440 --> 0:18:12.639 got these volcanoes erupting. What's causing all of this heat 0:18:12.760 --> 0:18:16.359 and and geologic activity inside Io It's believed to be 0:18:16.440 --> 0:18:20.120 tidal forces of Jupiter acting on the planet that you know, Jupiter. 0:18:20.840 --> 0:18:23.239 It's close enough to Jupiter that Jupiter is kind of 0:18:23.280 --> 0:18:26.480 working the planet with its gravity, and so as you're 0:18:26.520 --> 0:18:28.840 falling into a black hole, a similar kind of working 0:18:28.880 --> 0:18:32.639 would happen on you. Basically, imagine you're falling feet first 0:18:32.840 --> 0:18:36.520 into a relatively small black hole. At a certain radius 0:18:36.520 --> 0:18:38.760 from the black holes center, you would start to notice 0:18:38.840 --> 0:18:42.040 that the force of gravity pulling your feet is a 0:18:42.040 --> 0:18:45.080 lot stronger than the force of gravity pulling your head. 0:18:45.720 --> 0:18:48.400 And since Einstein, we know that the experience of gravity 0:18:48.480 --> 0:18:53.240 is subjectively equivalent to the experience of acceleration through space. Right. 0:18:53.560 --> 0:18:56.760 Gravity is just like being in an accelerating room. So 0:18:56.840 --> 0:19:00.280 imagine you're falling feet first and you discover that your 0:19:00.359 --> 0:19:04.800 feet are accelerating faster than your head is. If you 0:19:04.840 --> 0:19:07.439 were otherwise still alive, when this started to happen to you, 0:19:07.720 --> 0:19:11.080 it would stretch your body out until it ripped into pieces, 0:19:11.280 --> 0:19:13.960 and then those pieces would get stretched and ripped into 0:19:14.000 --> 0:19:16.760 smaller and smaller pieces, until you're just kind of a 0:19:16.800 --> 0:19:20.719 wet carbon particle jelly streaming through toward a point of 0:19:20.720 --> 0:19:24.040 infinite density. Also worth noting, if you did a cannonball 0:19:24.119 --> 0:19:27.080 into the singularity, Uh, then all of this would happen. 0:19:27.160 --> 0:19:30.920 But first, I'm not sure that has any impact in 0:19:31.000 --> 0:19:34.560 anybody's decision making. Oh, it has a lot of impact. 0:19:34.960 --> 0:19:38.720 Somebody should work that up that that should be a paper. Yeah, 0:19:38.720 --> 0:19:42.160 how would the body react? Uh? As a side note, 0:19:42.440 --> 0:19:45.040 you might have heard me mention smaller black holes here. 0:19:45.119 --> 0:19:47.440 Why Why did I mention smaller black holes? It's kind 0:19:47.440 --> 0:19:51.600 of counterintuitive, but actually smaller black holes will tend to 0:19:51.800 --> 0:19:55.680 kill you faster through tidal forces than larger black holes will. 0:19:55.880 --> 0:19:58.960 A much larger black hole actually has a more gentle 0:19:59.000 --> 0:20:04.320 gradient of gravity acceleration. But so we've been imagining one 0:20:04.480 --> 0:20:07.840 type of way of picturing this awesome event, the what 0:20:07.840 --> 0:20:11.240 what it's like to pass into a black hole? One 0:20:11.240 --> 0:20:13.040 of the things that I want to think about is, 0:20:13.080 --> 0:20:15.480 once you're within the event horizon of a black hole, 0:20:16.040 --> 0:20:19.600 does it even make sense to talk about you falling 0:20:19.600 --> 0:20:22.119 into the black hole? To talk about you and the 0:20:22.160 --> 0:20:26.400 black hole as separate objects if you can literally never 0:20:26.560 --> 0:20:30.480 leave no matter what, you are no longer an entity 0:20:30.560 --> 0:20:33.159 separate from the black hole itself. You are part of 0:20:33.200 --> 0:20:36.440 the black hole, and the black hole is you. That's true. 0:20:36.600 --> 0:20:39.399 Like you're no longer a denizen of the larger universe. 0:20:39.400 --> 0:20:42.320 You're denizen of that particular black hole. H and yeah, 0:20:42.320 --> 0:20:45.560 and arguably a part of its substance. Yeah. So maybe 0:20:45.800 --> 0:20:48.200 maybe a more transcendent way of thinking about it would 0:20:48.240 --> 0:20:50.280 be to say, okay, when you fall into a black hole, 0:20:50.560 --> 0:20:54.120 it doesn't just kill you. You get to become it 0:20:54.880 --> 0:20:57.440 consolation price. Yeah, alright, On that note, we're going to 0:20:57.520 --> 0:21:00.240 take a break and when we come back, we will 0:21:00.280 --> 0:21:03.720 discuss more of the mysteries and wonders within the black hole. 0:21:04.520 --> 0:21:08.520 Thank alright, we're back now. One of the things I 0:21:08.560 --> 0:21:10.720 know they talked about in the Darkness Visible event you 0:21:10.760 --> 0:21:13.920 saw in New York was the relationship between black holes 0:21:13.920 --> 0:21:17.560 and entropy? What what was the deal here? Alright, I'm 0:21:17.600 --> 0:21:20.160 gonna I'm gonna attempt to explain all of this and 0:21:20.280 --> 0:21:23.480 uh and I do just want to advise listeners more 0:21:23.520 --> 0:21:26.480 than usual that if if this doesn't completely make sense, 0:21:27.080 --> 0:21:30.240 do check out the talk, because I get to hear 0:21:30.560 --> 0:21:33.520 a pair of experts discuss it, uh in with more 0:21:33.600 --> 0:21:37.440 time and with with greater expertise. But but I will 0:21:37.440 --> 0:21:40.560 attempt to to summarize here. It is astrophysics. It is 0:21:40.640 --> 0:21:43.280 it is astrophysics, and we are talking about black holes. 0:21:43.680 --> 0:21:45.320 So one of the more interesting points brought up in 0:21:45.359 --> 0:21:48.840 the talk was that string theory actually helps us make 0:21:48.960 --> 0:21:53.040 sense of what's known as the intropy problem with black holes. 0:21:53.480 --> 0:21:56.359 The basic problem being is that is that how can 0:21:56.400 --> 0:21:59.639 a black hole be in a high entropy state if 0:21:59.680 --> 0:22:03.320 everything inside it is super condensed to a state of 0:22:03.520 --> 0:22:08.000 less entropy than normal matter, whereas the missing entropy and 0:22:08.280 --> 0:22:11.280 the thing is. According to string theory, you can say, well, 0:22:11.320 --> 0:22:13.479 the missing the missing intropy can be found in the 0:22:13.560 --> 0:22:17.439 six microscopic spatial dimensions that exist in addition to the 0:22:17.440 --> 0:22:20.359 three spatial dimensions that we can observe. And yes, I 0:22:20.400 --> 0:22:22.520 realize all that kind of may have sounded to some 0:22:22.600 --> 0:22:27.000 of you, like, uh, like a monologue from Ghostbusters. But 0:22:27.000 --> 0:22:29.520 but but it does it does make sense. Okay, So 0:22:29.840 --> 0:22:34.640 basics on string theory. String theory is an unproven hypothetical 0:22:34.680 --> 0:22:38.159 framework in physics that explain that goes toward explaining the 0:22:38.200 --> 0:22:41.280 more ultimate nature of our universe. We've got the Standard model, 0:22:41.680 --> 0:22:44.479 and you've got particles, and you've got energy and all that, 0:22:44.520 --> 0:22:47.760 and you're like, does something lie underneath all this? What 0:22:47.960 --> 0:22:51.879 generates its string theory? That the very basic version is 0:22:51.920 --> 0:22:54.560 that it posits that underneath all of our model of 0:22:54.560 --> 0:22:58.840 particle physics and everything are these vibrating strings. And these 0:22:58.880 --> 0:23:01.639 strings make up space, time and particles, and they can 0:23:01.760 --> 0:23:05.760 vibrate in different ways that create different kinds of phenomena 0:23:05.800 --> 0:23:08.360 and objects in our universe. Is that is that kind 0:23:08.359 --> 0:23:12.000 of close approximation. Uh, And so under string theory, it's 0:23:12.040 --> 0:23:14.600 this sort of mathematical framework we haven't been able to 0:23:14.640 --> 0:23:18.960 fully test yet, but under this mathematical framework, it is 0:23:19.000 --> 0:23:22.320 believed that there are more dimensions than just the three 0:23:22.359 --> 0:23:25.640 space dimensions and the one time dimension that we observe, right, 0:23:25.680 --> 0:23:29.240 and they're necessary for string theory to work. Um like this, 0:23:29.359 --> 0:23:31.359 this basically emerges from the math. And one of the 0:23:31.400 --> 0:23:34.080 things that that that Brian Green pointed out in the 0:23:34.080 --> 0:23:36.760 World Science Festival talk is that for for a long 0:23:36.800 --> 0:23:38.760 time this was kind of not really a dirty secret 0:23:38.760 --> 0:23:40.600 of string theory, but it was one of those things 0:23:40.600 --> 0:23:42.760 that was necessary by the math. But it wasn't something 0:23:42.760 --> 0:23:45.760 that necessarily they were putting out there first like saying, uh, 0:23:45.840 --> 0:23:50.280 you know, headline six dimensions, additional spatial dimensions. It was 0:23:50.320 --> 0:23:53.240 more like, we have this this this attempt to understand 0:23:53.280 --> 0:23:56.840 the universe and oh, by the way, six dimensional spatial dimensions. 0:23:56.920 --> 0:23:58.880 And we should mention that Brian Green is a big 0:23:58.920 --> 0:24:01.720 fan of string theory, been working on string three for years, 0:24:01.760 --> 0:24:05.359 but not everybody in the physics community is uh. String 0:24:05.400 --> 0:24:07.520 theory has plenty of critics, people who say, you know, 0:24:07.600 --> 0:24:10.119 this is an even science. It's not testable yet, so 0:24:10.160 --> 0:24:12.920 how could you you know? But the people who work 0:24:12.920 --> 0:24:15.119 on it say, well, we're trying to create a theoretical 0:24:15.119 --> 0:24:17.479 framework and maybe sometime in the future we could do 0:24:17.560 --> 0:24:20.320 tests to try to confirm it or disconfirm it. Yes. 0:24:20.760 --> 0:24:22.439 Now the other side of this, of course, is the 0:24:22.560 --> 0:24:26.920 entropy we're talking about. So the second law of thermot 0:24:26.960 --> 0:24:31.080 thermodynamic states that in a natural thermodynamic process, the sum 0:24:31.240 --> 0:24:36.320 of the entropies of the interacting thermodynamic dynamic systems increases, 0:24:36.680 --> 0:24:39.720 So things are going from low intropy to higher entropy. Um. 0:24:40.080 --> 0:24:41.959 The example that Brian Green throws out is that if 0:24:41.960 --> 0:24:43.560 you have a book's worth of page is stacked on 0:24:43.600 --> 0:24:47.280 top of each other in order, uh, that is low entropy, 0:24:47.400 --> 0:24:48.879 and then you throw it into the air and all 0:24:48.880 --> 0:24:50.719 the pages fall on the ground. Well, now it's gone 0:24:50.760 --> 0:24:53.280 to a high entroview state. In the former the low 0:24:53.359 --> 0:24:56.600 entropy state, less information was required to describe it. But 0:24:56.680 --> 0:24:59.480 in the because you just say, oh, well the information 0:24:59.520 --> 0:25:02.160 on page X is on the sixth page, etcetera, you'll 0:25:02.200 --> 0:25:05.320 find them in order in this stack. But now everything 0:25:05.760 --> 0:25:08.359 is in a high entropy state. You need more information 0:25:08.400 --> 0:25:11.439 to tell you where where everything is. You say, okay, 0:25:11.480 --> 0:25:15.800 page six is, well, it's it's over here, um in 0:25:15.800 --> 0:25:19.080 the middle of the field near pages you know, eight 0:25:19.119 --> 0:25:22.679 hundred and page seventy two, that sort of thing with 0:25:22.720 --> 0:25:26.560 a weasel chewin on it. Right, So when we looked 0:25:26.600 --> 0:25:29.320 back to black holes, yeah, you have to account the 0:25:29.320 --> 0:25:31.120 wee but in the weasels moving around, you gotta track 0:25:31.160 --> 0:25:33.560 the weasel. See, it's so much easier to keep track 0:25:33.560 --> 0:25:35.960 of everything when it's just in a stack. This is 0:25:36.000 --> 0:25:41.800 why good housekeeping is essential. So back to black holes. Though, 0:25:41.840 --> 0:25:46.119 when black holes merge, the area of the event horizon 0:25:46.480 --> 0:25:51.000 holds onto the entropy. But there's this lost information. Uh, 0:25:51.160 --> 0:25:53.119 and this is probably it's probably a terrible way of 0:25:53.119 --> 0:25:55.760 thinking about it. So please, you know, don't like really 0:25:55.840 --> 0:25:57.840 hold onto this or make a T shirt out of it. 0:25:57.920 --> 0:26:01.439 But if two circus clowns were to into a single clown, 0:26:02.080 --> 0:26:04.800 you might expect to have a circus clown with twice 0:26:04.840 --> 0:26:08.119 as many articles of clown clothing, twice as many buzzers, 0:26:08.560 --> 0:26:11.959 twice as many flowers and other like clown gimmicks. Right, uh, 0:26:12.119 --> 0:26:15.080 twice as much face paint. But no, there's something missing. 0:26:15.160 --> 0:26:17.439 Where did the missing clown gimmicks go? Where did the 0:26:17.440 --> 0:26:21.439 missing entropy go? Where the missing information go? Or it 0:26:21.520 --> 0:26:24.520 seems to be missing? Uh, seems to be there, seems 0:26:24.560 --> 0:26:27.600 to be a loss of information. Uh. Intropy is supposed 0:26:27.600 --> 0:26:29.720 to increase, but this would seem to be a decrease 0:26:29.760 --> 0:26:33.520 in entropy, which violates that second loft thermo dynamics. And 0:26:33.520 --> 0:26:37.639 then scientists also found an area increase in merging black holes, 0:26:37.880 --> 0:26:40.600 seeming to line up with the increase in entropy. UH. 0:26:40.680 --> 0:26:43.919 The area of the event horizon is somehow holding onto 0:26:43.960 --> 0:26:47.240 the information that's inside the black hole, and Stephen Hawking 0:26:47.320 --> 0:26:51.080 argued that there was a connection between the black hole 0:26:51.119 --> 0:26:54.679 area in intropy. There must be information, but the horizon 0:26:54.880 --> 0:26:58.840 is is featureless. There's no room for information there to 0:26:58.880 --> 0:27:01.760 be deciphered. So if you solve all of this with 0:27:01.760 --> 0:27:05.600 Einstein's equations, the black hole would seem to have zero entropy. 0:27:05.720 --> 0:27:07.720 It would seem to be a perfectly ordered state. But 0:27:07.840 --> 0:27:11.680 that can't be right now. Basically, as Brian Green described 0:27:11.680 --> 0:27:14.359 at the World Science Festival, you have these extra dimensions 0:27:14.359 --> 0:27:16.760 and string theory that emerges kind of a remainder, a 0:27:16.840 --> 0:27:20.399 kind of a problem, and with black holes you have 0:27:20.560 --> 0:27:23.879 this problem of missing introview, and when you combine the two, 0:27:24.359 --> 0:27:27.000 the problems would seem to kind of cancel each other out. 0:27:27.600 --> 0:27:31.320 Uh and in a way but possibly reveal what could 0:27:31.359 --> 0:27:33.960 be going on inside a black hole. It's still a puzzle. 0:27:34.000 --> 0:27:35.919 It's still a big mystery. You know, where does the 0:27:35.920 --> 0:27:39.159 intropy go when the black hole evaporates and uh, it 0:27:39.720 --> 0:27:44.240 radiates particles and this hawking radiation when it vanishes, what 0:27:44.280 --> 0:27:47.359 happens to the information? Uh? All and all of this 0:27:47.440 --> 0:27:50.280 is based on the math, by the way. Um, but 0:27:50.440 --> 0:27:53.520 it's yeah, it's it's it's fascinating. This is another one 0:27:53.520 --> 0:27:56.440 of those areas where where we were chasing the math 0:27:56.760 --> 0:28:00.119 to find the black hole, and we're still chasing the 0:28:00.160 --> 0:28:04.520 math to understand exactly how it's functioning. Yeah, this is 0:28:04.560 --> 0:28:07.480 one of the frontiers of science. I mean, it's an 0:28:07.480 --> 0:28:11.280 exciting realm because it's a place where you've got to 0:28:11.320 --> 0:28:16.480 have this, uh, this sort of clever cooperation between indirect 0:28:16.600 --> 0:28:21.440 kinds of observations from the experimentalists and clever innovations by 0:28:21.600 --> 0:28:25.440 the theorists, the people coming up with the mathematical framework 0:28:25.440 --> 0:28:27.800 in the theory. I mean, you can't like sample a 0:28:27.840 --> 0:28:31.160 black hole and just say, Okay, let's see what's going on. Right, 0:28:31.920 --> 0:28:34.600 So I realized a lot of that is is very 0:28:34.600 --> 0:28:38.320 difficult to relate to the human experience. So I think 0:28:38.320 --> 0:28:41.120 it's time to move on and talk about black holes 0:28:41.240 --> 0:28:44.080 and time. We've talked about like the sort of the 0:28:44.240 --> 0:28:48.240 visual experience and the the spatial experience of approaching and 0:28:48.240 --> 0:28:50.520 then injuring a black hole crossing its event arise, and 0:28:51.080 --> 0:28:53.280 but then there's this whole question about what happens with 0:28:53.360 --> 0:28:56.720 time because we're talking about space time. We're talking about 0:28:56.720 --> 0:29:00.600 an object that warps space time with its incredible math. Yeah. Now, 0:29:00.640 --> 0:29:03.200 one thing that's absolutely true that we know is that 0:29:03.280 --> 0:29:08.760 time is relative. So the outside observers version of what 0:29:08.840 --> 0:29:11.200 happens to you when you enter a black hole might 0:29:11.240 --> 0:29:14.640 be very different than your subjective experience of what happens 0:29:14.680 --> 0:29:16.760 to you when you enter a black hole, because you're 0:29:16.760 --> 0:29:19.560 not experiencing time in the same way. Yeah. Like, one 0:29:19.560 --> 0:29:21.360 of the key things that will touch on again here 0:29:21.480 --> 0:29:24.040 is you talk about these scenarios where one person enters 0:29:24.080 --> 0:29:26.760 the black hole and one person watches from behind the 0:29:26.800 --> 0:29:28.240 one in the front looks back at the one in 0:29:28.280 --> 0:29:31.000 the back. But then you cannot have a third observer 0:29:31.600 --> 0:29:34.440 who can see both inside a black hole and outside 0:29:34.440 --> 0:29:37.280 of the black hole like that. There that once you 0:29:37.360 --> 0:29:39.960 cross the event arise and that's it. Yeah, okay, well 0:29:39.960 --> 0:29:41.480 I think we've got to take a quick break and 0:29:41.520 --> 0:29:43.920 then after that we will come back and explore black 0:29:43.920 --> 0:29:49.520 holes in time than all right, we're back, so key 0:29:49.560 --> 0:29:52.920 and all of this is a phenomenon called time dilation, 0:29:53.160 --> 0:29:55.720 which we've discussed in the show before. This is the 0:29:55.760 --> 0:29:58.520 idea that time passes more slowly the closer you approach 0:29:58.600 --> 0:30:01.360 the speed of light, which of course is an unbreakable 0:30:01.360 --> 0:30:04.520 cosmic speed limit. Now, one thing we need to say there, though, 0:30:04.600 --> 0:30:07.520 is that the What what that means when you say is, 0:30:07.600 --> 0:30:09.280 let's say you get in a spaceship and you approach 0:30:09.360 --> 0:30:12.480 the speed of light, is that time passes more slowly 0:30:12.520 --> 0:30:16.800 relative to other observers for you, Uh, it doesn't necessarily 0:30:16.840 --> 0:30:20.160 mean that you would feel like you're living in slow motion. 0:30:20.240 --> 0:30:22.960 In fact, what it means is that you are living 0:30:23.200 --> 0:30:26.240 in normal time. But say if you get in a spaceship, 0:30:26.280 --> 0:30:27.960 travel at the speed of light or not at the 0:30:27.960 --> 0:30:30.040 speed of light, close to the speed of light, and 0:30:30.120 --> 0:30:32.760 come back even though it felt like time was passing 0:30:32.800 --> 0:30:35.440 normally for you. You might get back to Earth and 0:30:35.480 --> 0:30:38.200 then realize a lot of time has passed on Earth, 0:30:38.240 --> 0:30:41.800 where it seemed like much less time had passed for you. Right, 0:30:41.880 --> 0:30:43.480 And this is one of those things you could say 0:30:43.640 --> 0:30:46.280 is true on Earth as it is in heaven, because 0:30:46.320 --> 0:30:49.120 the the hands of a clock in a speeding train 0:30:49.520 --> 0:30:52.480 are going to move ever so slightly slower than those 0:30:52.480 --> 0:30:56.600 in a stationary On a stationary clock, the difference would 0:30:56.760 --> 0:30:59.280 not be humanly noticeable, but when the train pulled back 0:30:59.280 --> 0:31:01.200 around to the station and the two clocks would be 0:31:01.240 --> 0:31:05.040 off by billions of a second um. If such a 0:31:05.120 --> 0:31:10.200 train could attain nine point nine nine nine percent light speed, 0:31:10.600 --> 0:31:13.240 only one year would pass on board for every two 0:31:13.320 --> 0:31:16.000 hundred and twenty three years back at the train station, 0:31:16.240 --> 0:31:18.960 even though for the passengers it would feel like time 0:31:19.040 --> 0:31:20.960 was moving normally. Right, This would all be a matter 0:31:21.000 --> 0:31:23.560 of like comparing notes and uh and like looking at 0:31:23.640 --> 0:31:27.160 stop watches when you return. That's the thing. But speed 0:31:27.240 --> 0:31:29.880 isn't the only factor that affects time. On a much 0:31:29.920 --> 0:31:34.960 smaller scale, mass also influences time, so time slows down 0:31:35.000 --> 0:31:37.840 the closer you are to the center of a massive object. 0:31:37.960 --> 0:31:40.040 This is something that was explored to great effect in 0:31:40.040 --> 0:31:42.680 the movie Interstellar, which we mentioned earlier. You get really 0:31:42.720 --> 0:31:45.760 close to the supermassive black hole and and you're gonna 0:31:45.800 --> 0:31:49.240 have some real problems sinking up with your person way 0:31:49.280 --> 0:31:52.600 back in the space station. Yeah, indeed. Uh. And and 0:31:52.640 --> 0:31:54.160 you know, based on this, we know that there are 0:31:54.200 --> 0:31:56.560 places in the universe where time speeds up in places 0:31:56.600 --> 0:32:00.840 where it slows down. Uh. Time, as it's often pointed out, 0:32:00.960 --> 0:32:03.080 runs a little bit faster in space than it does 0:32:03.160 --> 0:32:06.719 down on Earth. A clock aboard and orbiting satellite experiences 0:32:06.800 --> 0:32:09.640 time dilation due to both the speed of its orbit 0:32:09.840 --> 0:32:13.000 and it's greater distance from the center of Earth's gravity. 0:32:13.080 --> 0:32:15.560 And we actually do have to make adjustments for this, 0:32:15.760 --> 0:32:19.920 like for GPS satellites, Uh, they need occasional we we 0:32:19.960 --> 0:32:24.440 need to occasionally adjust timekeeping between GPS satellites and what's 0:32:24.440 --> 0:32:28.960 going on on Earth. So so that's the real world 0:32:29.560 --> 0:32:32.720 version of this, like the accessible version of this that 0:32:32.800 --> 0:32:35.840 actually impacts life on Earth. But then there's the Then 0:32:35.920 --> 0:32:38.280 then we return to black holes though, because the closer 0:32:39.040 --> 0:32:42.280 one gets to a black hole, the stronger the gravity 0:32:42.280 --> 0:32:44.800 would be. And this is gonna have a dramatic effect 0:32:44.800 --> 0:32:49.040 on time making a supermassive black hole, in Hawkings words, 0:32:49.760 --> 0:32:53.080 a sort of natural time machine. The trick would be 0:32:53.120 --> 0:32:56.040 to avoid falling in, hitting just the right trajectory and 0:32:56.080 --> 0:32:59.240 your your spaceship or even your time ship. I guess 0:32:59.240 --> 0:33:01.480 it would be at this point it to orbit around 0:33:01.560 --> 0:33:06.280 the event horizon. High speed would keep you stable, but 0:33:06.480 --> 0:33:09.360 time would slow down by half. So you could take 0:33:09.440 --> 0:33:13.600 say a five year journey to travel ten years into 0:33:13.640 --> 0:33:16.000 the future. That might not seem like a lot, but 0:33:16.040 --> 0:33:19.000 it's ultimately the best the universe offers as far as 0:33:19.240 --> 0:33:23.080 time travel goes without getting into the paradox producing feedback 0:33:23.160 --> 0:33:26.680 loop destroying aspects of wormholes. Right now, this would only 0:33:26.720 --> 0:33:30.040 be travel into the future. I think, as we've discussed before, 0:33:30.880 --> 0:33:34.960 when people ask is time travel possible the questions the 0:33:35.000 --> 0:33:37.760 answer to the question seems to me travel into the 0:33:37.760 --> 0:33:41.520 past absolutely not. Travel into the future is not only possible, 0:33:41.560 --> 0:33:44.400 it is known to be real. Yeah, And it gets 0:33:44.440 --> 0:33:46.800 in this weird scenario where someone could say, Hey, you 0:33:46.800 --> 0:33:49.480 wanna you wanna get to let's say it's eighteen now, 0:33:49.640 --> 0:33:52.960 you want to get to the year Yes, all right, Well, 0:33:53.200 --> 0:33:55.480 how how many years do you want to take to 0:33:55.520 --> 0:33:57.360 get there? You want to take the standard ten. Do 0:33:57.360 --> 0:33:59.720 you want to take five? Well, if you want it 0:33:59.760 --> 0:34:02.520 to want to get there in five years, uh, you know, 0:34:03.000 --> 0:34:07.880 uh relativistically, then you're gonna have to jump on this spaceship. 0:34:07.960 --> 0:34:10.040 And all of our physics tells us this would work. 0:34:10.640 --> 0:34:15.720 But that's outside the event horizon. What what's time like? Uh? 0:34:15.760 --> 0:34:18.760 Within the event horizon? Yeah? Does it even make sense 0:34:18.840 --> 0:34:23.440 to say from an outside observer's perspective that anything happens 0:34:23.480 --> 0:34:27.000 inside a black hole? Is that even a meaningful concept? 0:34:27.400 --> 0:34:30.360 I mean, we're it certainly gets into an area where 0:34:30.400 --> 0:34:33.359 these are all decent questions, you know, because you sort 0:34:33.360 --> 0:34:35.400 of you can do this with a sort of physics breakdown. 0:34:35.440 --> 0:34:38.200 But then ultimately, yeah, what does it mean to be 0:34:38.239 --> 0:34:40.719 within the event horizon? Yeah? By the way, I meant 0:34:40.760 --> 0:34:42.719 that not to say that nothing happens. It was just 0:34:42.880 --> 0:34:44.879 I don't actually know the answer to that question. Well, 0:34:44.880 --> 0:34:48.000 I looked into this, and I was reading an article 0:34:48.120 --> 0:34:53.000 on Ask an Astronomer by Harvard physics graduate students Sarah 0:34:53.040 --> 0:34:57.000 Slater and uh and and she had this fascinating nugget. 0:34:57.080 --> 0:35:00.080 She's she's shared that quote. Everyone inside the event to 0:35:00.160 --> 0:35:03.640 horizon is a psychic whoa explain that okay. So she 0:35:03.760 --> 0:35:07.680 points out that outside of the event horizon, there are 0:35:07.719 --> 0:35:12.080 two criteria for remembering something. One it has to have 0:35:12.120 --> 0:35:15.200 been in the past, and two, it has to have 0:35:15.320 --> 0:35:18.759 happened at a distance no more than what light could 0:35:18.760 --> 0:35:22.160 have traveled since it happened. Okay. So that sort of 0:35:22.200 --> 0:35:26.960 means like, we can't remember events that took place farther 0:35:27.040 --> 0:35:30.920 away than the observable universe because it would have taken 0:35:31.080 --> 0:35:33.920 light longer than the history of the universe to cross 0:35:34.000 --> 0:35:36.520 that distance to reach us. There's no way we could 0:35:36.520 --> 0:35:39.480 have that information, right, I mean, this is like basically 0:35:39.719 --> 0:35:41.359 I'm gonna put that on the shelf and say that's 0:35:41.360 --> 0:35:45.120 space and time as it relates to our our ability 0:35:45.120 --> 0:35:49.399 to remember something. But inside the event horizon, things get 0:35:49.400 --> 0:35:53.280 flipped around space and time you could say, become switched. 0:35:53.640 --> 0:35:55.200 So now these are the two These are the two 0:35:55.200 --> 0:35:59.200 criteria within the event horizon for remembering something. One it 0:35:59.320 --> 0:36:01.960 has to have happened farther from the center of the 0:36:02.000 --> 0:36:06.319 black hole, uh than where you are right now. And 0:36:06.560 --> 0:36:10.080 number two, if T is in the letter T is 0:36:10.120 --> 0:36:12.680 the time that it would take light to travel to 0:36:12.760 --> 0:36:16.000 you from the location of the event, then it happened 0:36:16.000 --> 0:36:20.080 either no more than tea hours ago or tea hours 0:36:20.160 --> 0:36:23.720 into the future. So I'm gonna just read this direct 0:36:23.840 --> 0:36:27.760 quote from her quote if you look away from the center. 0:36:27.840 --> 0:36:30.920 And again this goes back to our earlier ideas of 0:36:31.080 --> 0:36:34.120 crossing the event horizon and looking back or trying to 0:36:34.160 --> 0:36:36.640 look back. She says, quote, if you look away from 0:36:36.640 --> 0:36:39.840 the center, though, you can see two images of everything, 0:36:40.480 --> 0:36:43.080 one from tea hours in the past and one from 0:36:43.160 --> 0:36:46.439 tea hours in the future. For nearby objects, these two 0:36:46.440 --> 0:36:49.560 images will look just the same, since t will be 0:36:49.680 --> 0:36:52.560 very small due the due to the large speed of light. 0:36:53.040 --> 0:36:56.320 For far away objects, though, they could be completely different. 0:36:56.560 --> 0:36:59.520 So you could see the past beginning of something and 0:36:59.600 --> 0:37:03.520 it's few your end. At the same time, spacetime is twisted. 0:37:04.360 --> 0:37:05.759 And then there's this. If you were to enter a 0:37:05.800 --> 0:37:09.840 black hole, theoretically speaking, an outside observer might watch you 0:37:09.920 --> 0:37:12.279 crash and burn on the event arise and destroyed by 0:37:12.280 --> 0:37:15.480 all that hawking radiation, all of your information spread out 0:37:15.480 --> 0:37:19.560 across the face of the dark sphere. Uh because again 0:37:19.560 --> 0:37:22.520 the information can't be lost, but your experience would be 0:37:22.560 --> 0:37:25.320 one of free fall for the rest of your life. 0:37:25.920 --> 0:37:28.960 And in short, this is the firewall paradox. Uh, there's 0:37:29.000 --> 0:37:32.120 no third witness who can see both within and without 0:37:32.320 --> 0:37:35.560 the event Arizona. And to me, that's all just mind 0:37:35.600 --> 0:37:38.839 going to try and and uh and and contemplate. Yeah, 0:37:38.840 --> 0:37:41.520 I feel like I'm still trying to understand it. Um. 0:37:41.560 --> 0:37:44.520 I mean it drives home the way that black holes 0:37:44.560 --> 0:37:50.040 are kind of They're great because they are a reality 0:37:50.120 --> 0:37:53.880 that brings to life all of these impossible relativity experiments 0:37:53.920 --> 0:37:57.520 that people try to use to explain how weird spacetime 0:37:57.560 --> 0:37:59.719 really is. One of the things we talked about in 0:37:59.719 --> 0:38:01.440 the last episode is you know, if you were to 0:38:01.480 --> 0:38:04.000 just go based on your intuitions, you'd probably think, well, 0:38:04.400 --> 0:38:08.200 space and time are are fixed, and the speed of 0:38:08.320 --> 0:38:11.279 light is can be moved all around. But in fact 0:38:11.320 --> 0:38:14.200 it's exactly the opposite. Speed of light is fixed speed 0:38:14.200 --> 0:38:16.560 of light and a vacuum is fixed and space and 0:38:16.600 --> 0:38:20.239 time can be stretched all around. And you can't really 0:38:20.280 --> 0:38:22.560 internalize that. But people try to come up with all 0:38:22.600 --> 0:38:27.680 these impossible scenarios to illustrate the principle. At the black hole, 0:38:28.239 --> 0:38:30.000 you don't have to come up with scenarios. This just 0:38:30.040 --> 0:38:32.959 apparently is what black holes do. Now. At this point 0:38:32.960 --> 0:38:35.040 in the podcast, is we're beginning to wind down here, 0:38:35.440 --> 0:38:37.520 I thought it might be fun to just talk about 0:38:37.560 --> 0:38:41.160 a couple of questions that that frequently come up. Either 0:38:41.680 --> 0:38:43.840 some of these we have received as emails from people, 0:38:44.040 --> 0:38:45.799 and then others are just sort of general questions that 0:38:45.840 --> 0:38:50.480 arise from sci fi treatments of black holes, including event Horizon. Okay, 0:38:50.480 --> 0:38:52.640 so the first one is if and I know we've 0:38:52.640 --> 0:38:55.560 received this from listeners, if I'm pulled into a black hole, 0:38:55.680 --> 0:38:57.960 will I then come back out of a white hole? 0:38:58.160 --> 0:39:00.080 And I think sometimes this is an area where we 0:39:00.080 --> 0:39:02.080 we fall into the trap of thinking of black holes 0:39:02.120 --> 0:39:06.120 more as wormholes. But the white hole concept is in 0:39:06.200 --> 0:39:09.759 fact a byproduct of general relativity. But it's even more 0:39:09.800 --> 0:39:13.400 of a mathematical phantom. In many respects, it is the 0:39:13.440 --> 0:39:15.640 reverse of a black hole. It's not a place where 0:39:15.719 --> 0:39:18.880 matter is lost, but rather a place where matter is born. 0:39:19.360 --> 0:39:21.759 I've seen it explained as sort of like the Big 0:39:21.800 --> 0:39:25.719 Bang singularity but not but not quite the same. But 0:39:25.840 --> 0:39:29.880 it also can't actually exist in our universe. Yeah, so 0:39:30.120 --> 0:39:32.000 I hadn't heard this. I've heard the white holes were 0:39:32.040 --> 0:39:36.319 still kind of a speculative possibility. Well, this is, well, 0:39:36.920 --> 0:39:39.560 my understanding of it and again this could be that 0:39:39.719 --> 0:39:41.719 this could be incorrect, and I may have to be 0:39:41.840 --> 0:39:47.200 corrected on this later. But my understand my my understanding 0:39:47.200 --> 0:39:49.760 of it that it is that it emerges from the math. 0:39:50.200 --> 0:39:51.680 But it's one of these things that emerges from the 0:39:51.719 --> 0:39:53.720 math that that we're like, well, that doesn't really square 0:39:53.800 --> 0:39:56.799 up with what we we actually expect to see in 0:39:56.840 --> 0:40:02.040 the universe. Astrophysicist Karen master Is once described it this way, quote, 0:40:02.120 --> 0:40:04.719 there is only such a thing as a white hole 0:40:05.120 --> 0:40:07.879 in the theory of black holes, and no such thing 0:40:08.200 --> 0:40:12.239 is possible, is possible physically. Well, I'm sure she knows 0:40:12.239 --> 0:40:14.239 a million times more about this than I do, but 0:40:14.280 --> 0:40:16.880 I would just point out that that used to be 0:40:16.960 --> 0:40:21.040 what the astronomers said about black holes. Yeah, but I'm 0:40:21.080 --> 0:40:23.040 not using that to say white holes exist. I mean, 0:40:23.040 --> 0:40:25.280 I'm sure she's probably drawing on a lot of facts 0:40:25.320 --> 0:40:28.040 that that I'm not aware of my But basically, my 0:40:28.040 --> 0:40:31.080 my read from this information is that the answer to 0:40:31.200 --> 0:40:32.839 if if I go into a black hole, I come 0:40:32.840 --> 0:40:36.279 out a white hole, the answer is is probably no. 0:40:36.920 --> 0:40:40.600 And probably you're thinking more about a wormhole here, You're 0:40:40.600 --> 0:40:43.520 not really you're not really picturing what a black hole 0:40:43.640 --> 0:40:47.279 and indeed, a white hole would actually be well, I'm 0:40:47.440 --> 0:40:50.040 more I'm inclined to take the astrophysicists word on it, 0:40:50.160 --> 0:40:53.160 so so I'll go with that. No, no white holes. Okay. 0:40:53.280 --> 0:40:56.920 So another frequently asked question, and this one's a lot 0:40:56.920 --> 0:40:59.279 more fun I have to have to say, is could 0:40:59.280 --> 0:41:01.600 we one day harness the power of a black hole? 0:41:02.120 --> 0:41:05.040 Perhaps like what we see an event horizon, it's a 0:41:05.080 --> 0:41:08.160 black hole. Drive tell me event horizon as possible. Kay, 0:41:08.360 --> 0:41:11.279 let's hear it. Okay, So, first of all, this is 0:41:11.280 --> 0:41:13.640 probably a good time to refresh everyone on the Kardashian scale, 0:41:13.719 --> 0:41:17.160 which we referenced earlier. This is the idea that this 0:41:17.200 --> 0:41:19.520 is just like a very rough way of understanding like 0:41:19.520 --> 0:41:25.239 what would be the technological levels of possible um civilizations 0:41:25.360 --> 0:41:28.040 in the universe. And it's judge based on how much 0:41:28.160 --> 0:41:31.120 energy you can take control of, right and like truly 0:41:31.160 --> 0:41:34.200 take control of. So, for instance, Type one civilizations are 0:41:34.239 --> 0:41:37.160 masters of planetary energy, meaning they can harness this some 0:41:37.440 --> 0:41:40.719 energy of an entire world. We're not there yet, no, 0:41:40.880 --> 0:41:43.759 we would still be a type zero civilization. Type to 0:41:43.920 --> 0:41:47.560 civilizations can summon the power of an entire star system, 0:41:47.600 --> 0:41:49.880 and those would be I mean these would be godlike 0:41:50.000 --> 0:41:52.360 entities if we were to encounter them, if I remember correctly, 0:41:52.440 --> 0:41:55.799 like the the the aliens we encounter in two thousand 0:41:55.840 --> 0:41:59.319 and one Space Odyssey are probably Type two. Yeah, so 0:41:59.360 --> 0:42:02.520 they know you. Dyson's fears would be an example. So 0:42:02.560 --> 0:42:05.600 if you you create a structure that can harness and 0:42:05.640 --> 0:42:08.720 make usable all of the radiation coming off of a star, 0:42:10.160 --> 0:42:13.760 and then Type three civilizations command energy on a galactic scale, 0:42:14.080 --> 0:42:17.160 and that we can't even picture that that's god like 0:42:17.360 --> 0:42:19.480 to a level that it's yeah, I think it's difficult 0:42:19.520 --> 0:42:23.279 for us to even summon. Yeah, it's difficult for me 0:42:23.320 --> 0:42:26.000 to even imagine that as well, it would do because 0:42:26.080 --> 0:42:30.120 Type two civilizations would appear as God's Type three. We 0:42:30.600 --> 0:42:32.440 I don't know, we don't even know they're there. If 0:42:32.440 --> 0:42:34.040 we could, they could be all in the room with us. 0:42:34.080 --> 0:42:37.480 And who are we? Who are we to to to 0:42:37.480 --> 0:42:41.080 to even notice them? So anyway, harvesting the power of 0:42:41.120 --> 0:42:43.719 a black hole sounds exactly like the type of thing 0:42:43.840 --> 0:42:48.240 a Type to civilization would be into um and in fact, 0:42:48.320 --> 0:42:51.120 even a Type zero civilization like our own can think 0:42:51.120 --> 0:42:53.960 of a few ways one might go about it. So 0:42:54.120 --> 0:42:57.880 remember that hawking radiation that we've mentioned already that's emitted 0:42:57.880 --> 0:43:01.000 by a black hole. Well one to harvest that, yeah, 0:43:01.120 --> 0:43:06.120 just turned into a nuclear reactor. Well in, physicist George 0:43:06.239 --> 0:43:10.320 unrou and Robert Wald suggested that one could essentially lower 0:43:10.360 --> 0:43:14.160 a bucket toward the event horizon, collect this radiation, and 0:43:14.200 --> 0:43:16.880 then drawl it back out. Now, if you let the 0:43:17.040 --> 0:43:19.480 bucket go through the event horizon, you would not be 0:43:19.480 --> 0:43:21.759 able to get it back right, Yeah, there's no that 0:43:22.719 --> 0:43:25.920 the light cannot escape, and certainly a type two Kardashian 0:43:26.040 --> 0:43:28.080 bucket would not be able to escape. Right. That would 0:43:28.080 --> 0:43:30.640 be like the black holes. Like the neighbor who you know, 0:43:30.680 --> 0:43:35.080 your frisbee goes in their yard and that's my bucket. Now. Now, 0:43:35.480 --> 0:43:38.000 there's some problems with this though, because the tension of 0:43:38.040 --> 0:43:41.000 the rope here is an issue. Adam Brown of the 0:43:41.239 --> 0:43:46.120 Princeton Center of for the Theoretical Science countered that the 0:43:46.239 --> 0:43:49.319 rope descending towards such high gravity would only be able 0:43:49.360 --> 0:43:52.600 to support its own mass, not the additional mass of 0:43:52.680 --> 0:43:56.160 this mind hawking radiation. Plus, as you know, it also 0:43:56.200 --> 0:43:58.399 needs to be able to withstand the crazy hey heat 0:43:58.480 --> 0:44:04.320 of hawking radiation, as with the bucket. Now in albion 0:44:04.400 --> 0:44:08.080 Lawrence and A. Mill Martinique of the University of Chicago 0:44:08.520 --> 0:44:12.640 proposed that we could instead dip strings into the black 0:44:12.680 --> 0:44:17.200 hole and hawking radiation would climb up out on its own. 0:44:17.680 --> 0:44:19.960 So this would be like I've seen it compared to 0:44:20.239 --> 0:44:22.799 U like the like an oil wick in a in 0:44:22.840 --> 0:44:26.839 an oil lantern. So you're not getting anything back from 0:44:26.840 --> 0:44:30.920 beyond the event horizon, but you're harvesting the hawking radiation 0:44:30.960 --> 0:44:33.879 around it. Yeah, kind of almost like luring it out. 0:44:34.840 --> 0:44:36.640 So you know, this is this is an interesting think 0:44:36.640 --> 0:44:38.600 about and you would be able to to to mind 0:44:38.680 --> 0:44:41.520 just a colossal amount of energy this way. But what 0:44:41.640 --> 0:44:45.200 about doing more of this event horizon model Event Horizon 0:44:45.239 --> 0:44:48.800 the movie? What about actually, you say, capturing a small 0:44:48.800 --> 0:44:52.319 black hole, maybe a primordial black hole, using that to 0:44:52.320 --> 0:44:56.120 power your space or making your own singularity. Well, on 0:44:56.120 --> 0:44:58.080 one hand, that sounds kind of impossible, But on the 0:44:58.080 --> 0:45:00.680 other hand, we should be clear that a black hole 0:45:00.920 --> 0:45:03.839 doesn't have to come from a star in principle at least, 0:45:03.920 --> 0:45:06.839 I mean, we we don't have any technology for like 0:45:07.120 --> 0:45:11.080 making big old black holes. But in order to create 0:45:11.120 --> 0:45:12.839 a black hole, all you have to do is get 0:45:12.920 --> 0:45:16.360 an amount of mass within Swart shield radius. Right. And 0:45:16.400 --> 0:45:18.520 if you can do that, you've made a black hole. 0:45:18.520 --> 0:45:21.480 It doesn't have to be a collapse stellar remnant, right, 0:45:21.600 --> 0:45:24.880 And then arguably you could make one out of energy 0:45:24.960 --> 0:45:28.359 instead of just pure mass. So this is what's known 0:45:28.360 --> 0:45:32.759 as a swart shield. Google blitz, Google blitz, google blitz. Yes, 0:45:32.840 --> 0:45:35.600 sounds like a brand of blender or something, yeah, or 0:45:35.719 --> 0:45:38.800 a delicious breakfast cereal or part of your your complete breakfast. 0:45:39.400 --> 0:45:44.200 So this is the brainchild of theoretical physicist John Archibald 0:45:44.200 --> 0:45:48.760 Wheeler Wheeler and uh, it's the google blitz is German 0:45:48.800 --> 0:45:51.399 for ball lightning. Uh. And the idea is that these 0:45:51.400 --> 0:45:54.880 are These would be concentrations of energy so intense that 0:45:54.960 --> 0:45:58.120 they form their own event horizons and collapse on themselves. 0:45:58.719 --> 0:46:01.319 And it would need for this to work to be 0:46:01.520 --> 0:46:05.160 for this to be something you could actually utilize, it 0:46:05.160 --> 0:46:07.719 would need to be smaller than a proton. It would 0:46:07.719 --> 0:46:10.399 be incredibly hot, but if you could contain it, you'd 0:46:10.440 --> 0:46:13.480 have just immense energy at your disposal. Now, I'm not 0:46:13.520 --> 0:46:16.040 the biggest star Trek the next generation buff I like 0:46:16.120 --> 0:46:18.959 watched all these episodes, I think every evening at nine 0:46:19.000 --> 0:46:22.600 pm back in um in middle school, watched them on syndication, 0:46:22.640 --> 0:46:24.799 But it's been a long time since I've viewed them. 0:46:24.920 --> 0:46:27.880 You went down to the planets, to the pottered plants. Oh, yeah, 0:46:27.920 --> 0:46:29.920 I I think I watched them them all back in 0:46:29.960 --> 0:46:31.920 the day. But there was an episode that I do 0:46:31.960 --> 0:46:35.920 not directly remember, titled Timescape, and it reveals that a 0:46:36.000 --> 0:46:39.560 Romulan warbird is powered by one of these uh sword 0:46:39.640 --> 0:46:42.080 shield google blitz uh and it didn't, but it ends 0:46:42.160 --> 0:46:45.160 up resulting in all these temporal anomalies. Uh. And that's 0:46:45.239 --> 0:46:47.359 you know, the plot of the show is like, what's 0:46:47.360 --> 0:46:50.480 happening to time? Oh, it's something that Romulans did. Um. 0:46:50.520 --> 0:46:53.840 I don't remember it myself, but I've seen it cited 0:46:54.000 --> 0:46:57.759 as a as as an episode that utilizes this concept. Yeah, 0:46:57.760 --> 0:46:59.759 if Wheeler wants to try it out, I'd say let's 0:46:59.800 --> 0:47:02.759 go with Wheeler's I D idea. But I like thinking 0:47:02.800 --> 0:47:05.520 of it. This. What if you create this uh this 0:47:05.520 --> 0:47:09.000 this artificial black hole or this uh this this little 0:47:09.040 --> 0:47:11.640 lightning ball and then you drop it on the floor. 0:47:12.160 --> 0:47:13.920 That's got to be the worst. It's you know, it's 0:47:13.960 --> 0:47:17.360 bad enough when you say, drop a hummingbird feeder onto 0:47:17.400 --> 0:47:19.600 the kitchen floor and you get sugar water everywhere. What 0:47:19.640 --> 0:47:22.560 happens when you drop a black hole that's hard to 0:47:22.560 --> 0:47:26.279 clean up? Here's a hint. It's sticky, And I think 0:47:26.320 --> 0:47:30.120 that sums up the whole episode right there. Well, you know, 0:47:30.200 --> 0:47:32.080 I would say that there's all kinds of other black 0:47:32.080 --> 0:47:34.360 hole stuff we didn't even get to. So maybe we 0:47:34.360 --> 0:47:36.320 can come back again in the future. I just figured 0:47:36.320 --> 0:47:38.320 three episodes in a row, that's a lot. We probably 0:47:38.320 --> 0:47:41.160 shouldn't push it to four this week, I I think, 0:47:41.200 --> 0:47:42.759 so we have to move on to other topics and 0:47:42.760 --> 0:47:45.560 then we can return later because, as we've already touched 0:47:45.600 --> 0:47:49.560 on the the exploration of black holes is ongoing. It 0:47:49.680 --> 0:47:52.319 is far from a closed book. Yeah, we're learning. We're 0:47:52.440 --> 0:47:55.520 learning new stuff about black holes this year, especially with say, 0:47:55.520 --> 0:47:58.440 the research into Sagittarys, a star in the middle of 0:47:58.440 --> 0:48:01.440 our galaxy going on just this year. Yeah. So hey, 0:48:01.520 --> 0:48:04.120 maybe at the end of we can come back and 0:48:04.120 --> 0:48:07.080 we just we can discuss what we know now about 0:48:07.800 --> 0:48:11.600 about singularities that we did not know just a year earlier. 0:48:11.640 --> 0:48:13.959 One of the most interesting things mentioned in that World 0:48:13.960 --> 0:48:17.000 Science Festival event that we keep referring to is the 0:48:17.040 --> 0:48:19.879 idea that observations of black holes that are just now 0:48:19.920 --> 0:48:23.600 coming online, Like what we're finally learning about sagittarys a 0:48:23.719 --> 0:48:27.279 star in fact, seems to be though this could this 0:48:27.320 --> 0:48:30.560 could change, but at least seems in initial observations to 0:48:30.640 --> 0:48:34.520 be challenging some of the findings of general relativity. Yeah, 0:48:34.920 --> 0:48:37.000 so what do you what do you do with that? 0:48:37.040 --> 0:48:39.239 What happens when you do an experiment you think it's 0:48:39.239 --> 0:48:42.839 a well designed experiment, but then it disagrees with Einstein? 0:48:43.400 --> 0:48:46.120 Well it's it's yeah, I mean, if they discussed in 0:48:46.160 --> 0:48:48.279 that of that talk, it's like you you, first of all, 0:48:48.320 --> 0:48:51.200 you might question, well, one of my results actually saying, 0:48:51.239 --> 0:48:53.520 but then you may be reaching the point where you're 0:48:53.520 --> 0:48:57.799 having to move beyond, uh, these theories and work with 0:48:57.880 --> 0:49:01.000 new theories. So as we learn more about black holes, 0:49:01.040 --> 0:49:04.759 we're not just learning more about this arguably kind of 0:49:04.800 --> 0:49:08.120 abstract seeming thing that has no direct influence over our 0:49:08.160 --> 0:49:10.080 lives here on Earth. But it changed. But they have 0:49:10.120 --> 0:49:12.960 the ability to change our understanding of the cosmos itself. 0:49:13.000 --> 0:49:15.680 I mean, wouldn't it be a fascinating thing if we 0:49:15.680 --> 0:49:19.800 were alive to see a new better theory of gravity emerge? 0:49:20.520 --> 0:49:23.160 It would? It would? It would it would change everything. 0:49:23.200 --> 0:49:25.239 It's like it's like them. It's it's kind of like 0:49:25.280 --> 0:49:28.680 when they made another Blade Runner movie, except except even 0:49:28.760 --> 0:49:31.839 more ground shaking. You know, like you grow up thinking 0:49:31.840 --> 0:49:33.520 you're only going to ever have that one, and then 0:49:33.560 --> 0:49:36.040 they go and make another one, and then likewise you 0:49:36.280 --> 0:49:38.239 we would be living in a in a world in 0:49:38.280 --> 0:49:42.719 which we had our third gravitational theory, So third major one. Yeah, 0:49:42.840 --> 0:49:46.520 that would be really cool. Yeah. So yeah, astrophysicists, please 0:49:46.560 --> 0:49:50.600 go out there and break Einstein kick his butt. Alright, Well, 0:49:50.600 --> 0:49:53.920 on that note, we're going to uh, we're going to 0:49:54.040 --> 0:49:56.319 rock it away from the event horizon. Now, we are 0:49:56.400 --> 0:49:59.799 going to close this episode out. As always, we urge 0:49:59.800 --> 0:50:01.520 you to check out Stuff to Blow your Mind dot com. 0:50:01.520 --> 0:50:04.600 That's the mothership. That's what we'll find all the podcast episodes. 0:50:04.920 --> 0:50:07.640 You'll find videos and blog posts there as well, also 0:50:07.719 --> 0:50:10.160 links out to our various social media accounts. Oh it's 0:50:10.160 --> 0:50:11.600 stuff to Blow your Mind dot com. 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