WEBVTT - From the Vault: Where the Shadows Lie, Part 1 0:00:06.400 --> 0:00:08.520 Hey, welcome to Stuff to Blow Your Mind. My name 0:00:08.600 --> 0:00:09.680 is Robert Lamb. 0:00:09.600 --> 0:00:12.360 And I am Joe McCormick, and it's Saturday, so we're 0:00:12.360 --> 0:00:15.040 heading into the vault for an older episode of the show. 0:00:15.400 --> 0:00:18.720 This one originally published October twenty fourth, twenty twenty three, 0:00:18.840 --> 0:00:21.759 so keeping the Halloween vibes going, at least on the vault. 0:00:22.400 --> 0:00:25.840 This is part one of our series about shadows. 0:00:26.239 --> 0:00:28.720 All right, let's do it. 0:00:30.760 --> 0:00:34.720 Welcome to Stuff to Blow Your Mind, a production of iHeartRadio. 0:00:40.560 --> 0:00:43.080 Hey, welcome to Stuff to Blow your Mind. My name 0:00:43.159 --> 0:00:43.800 is Robert. 0:00:43.560 --> 0:00:47.560 Lamb and I am Joe McCormick. And today our October 0:00:47.680 --> 0:00:50.640 journey continues. If you're new to the show, we spend 0:00:50.720 --> 0:00:54.120 all of October covering spooky subjects, and we are plowing 0:00:54.240 --> 0:00:57.080 right on toward Halloween at a frightening pace, at such 0:00:57.080 --> 0:00:58.880 a pace that by the time we reach it, our 0:00:58.920 --> 0:01:02.240 skin may be seer by the wind. But today we 0:01:02.280 --> 0:01:05.160 wanted to embark on a new series of Halloween related 0:01:05.200 --> 0:01:10.320 episodes about shadows. Before we started, I was thinking about 0:01:10.520 --> 0:01:14.280 the series on necromancy that we published earlier this month, 0:01:14.319 --> 0:01:17.039 in which we explored a lot of ancient accounts of 0:01:17.040 --> 0:01:20.440 people summoning the dead, especially to get information about the 0:01:20.480 --> 0:01:23.680 future or some of the kind of hidden information from them, 0:01:24.080 --> 0:01:28.520 And we talked about stories that assumed the ancient Greek 0:01:28.760 --> 0:01:33.839 model of the afterlife a subterranean realm of darkness called hades, 0:01:34.360 --> 0:01:37.720 where the souls of the dead dwell in a weak, pitiable, 0:01:37.800 --> 0:01:42.200 and insubstantial form. So this would be unlike modern Christian 0:01:42.280 --> 0:01:45.480 notions of the dead dwelling either in heavenly bliss or 0:01:45.560 --> 0:01:49.880 infernal punishment. Haiti seems to be most often thought of 0:01:49.920 --> 0:01:53.919 as a gloomy, forlorn dungeon where your spirit is locked 0:01:53.920 --> 0:01:57.480 away forever, more like a slowly fading memory. It's not 0:01:57.640 --> 0:02:01.160 really a punishment, and basically everybody goes there, but it's 0:02:01.280 --> 0:02:04.320 not good. It's better to be alive. I guess. The 0:02:04.360 --> 0:02:06.600 only real exception seems to be like if you're turned 0:02:06.600 --> 0:02:09.680 into a god, which occasionally happens if you're really cool. 0:02:10.120 --> 0:02:11.480 Yeah, but you got to have you gotta have an 0:02:11.560 --> 0:02:13.560 end for that. Yeah, not just they don't have that 0:02:13.600 --> 0:02:14.760 out there, just anybody. 0:02:15.400 --> 0:02:19.200 So anyway, relevant to our topic. In this next series 0:02:19.240 --> 0:02:23.320 of episodes, I was thinking about how in English translations, 0:02:23.360 --> 0:02:27.360 for example, of the Homeric myths. These dead souls that 0:02:27.480 --> 0:02:32.600 populate the underworld here are sometimes known as shades. I 0:02:32.639 --> 0:02:35.120 think this terminology comes up in the story, for example, 0:02:35.120 --> 0:02:38.919 in the Odyssey, where Odysseus goes to the edge of 0:02:38.960 --> 0:02:41.840 the underworld in order to summon up shades. I think 0:02:41.840 --> 0:02:43.919 he wants to speak to the shade of Tyresius. 0:02:44.360 --> 0:02:45.160 I believe that's right. 0:02:45.240 --> 0:02:47.359 Yes, But he sees his mom, he sees a bunch 0:02:47.400 --> 0:02:50.239 of people, he waves a sword at him, he slaughters 0:02:50.280 --> 0:02:53.600 a ram, and all that. And I was wondering when 0:02:54.000 --> 0:02:56.959 the English translations use the word shade here, does that 0:02:57.240 --> 0:03:00.840 mean shadows just in the regular sense of shadow, And 0:03:00.919 --> 0:03:04.600 does that usage, if so, go back to the original Greek, 0:03:05.080 --> 0:03:08.079 as best I can tell, it does. I'm not a 0:03:08.120 --> 0:03:10.440 Greek scholar here, but I was looking up some Greek 0:03:10.480 --> 0:03:13.640 English lexical sources, and from what I could find, it 0:03:13.680 --> 0:03:17.000 looks like the Greek word used here is skia, the 0:03:17.280 --> 0:03:21.760 Latin equivalent being umbra. And this word does indeed carry 0:03:21.880 --> 0:03:25.960 these multiple meanings. It could be used to refer to ghosts, 0:03:26.040 --> 0:03:28.519 to spirits of the dead, like the kind that are 0:03:28.560 --> 0:03:30.920 called forth to drink the blood of the ram and 0:03:30.960 --> 0:03:34.400 tell the future to Odysseus, or it could refer to 0:03:34.480 --> 0:03:38.360 the utterly mundane shade and shadow cast by a tree, 0:03:38.480 --> 0:03:41.200 or a mountain, or a person, just whatever blocks out 0:03:41.240 --> 0:03:45.600 the sun. And I thought this double meaning was very interesting. 0:03:45.960 --> 0:03:49.600 What is it about the mundane shadows we experience every 0:03:49.640 --> 0:03:53.960 single day that would cause people to give them this 0:03:54.160 --> 0:03:56.080 hair raising secondary meaning. 0:03:56.480 --> 0:03:59.920 This is a great question, Yeah, because shadows are every 0:04:00.080 --> 0:04:02.760 where there that you know, we encounter our own shadow 0:04:02.800 --> 0:04:06.400 every day. And yet the term shadow, the idea of 0:04:06.440 --> 0:04:10.840 a shadow carries a lot of weight, certainly supernaturally and 0:04:11.240 --> 0:04:15.440 fictionally and folklorically, as we'll get into in a bit here, 0:04:15.680 --> 0:04:19.080 but just linguistically, it does a lot of legwork, you know. 0:04:20.560 --> 0:04:23.919 I decided to turn to Brewer's Dictionary of Phrase and 0:04:23.960 --> 0:04:26.800 Fable on this one. It's often a fun way to 0:04:26.880 --> 0:04:31.359 sort of dive into not just the meaning of words, 0:04:31.360 --> 0:04:36.520 but also just like antiquated usages of those words. So 0:04:36.760 --> 0:04:39.159 the author here reminds us that shadow is a word 0:04:39.240 --> 0:04:43.960 with numerous figurative and applied meanings. A shadow maybe a ghost, 0:04:44.200 --> 0:04:48.240 as we see in Macbeth hence horrible shadow. It may 0:04:48.279 --> 0:04:52.120 also be a faint representation, as in a shadow of 0:04:52.160 --> 0:04:56.680 a doubt. It may also mean a constant attendant, and 0:04:56.720 --> 0:05:01.040 Brewers specifically references Milton's paradise lost here sin and her 0:05:01.120 --> 0:05:01.919 shadow death. 0:05:02.400 --> 0:05:04.280 It's hard for me to imagine that pairing of her 0:05:04.400 --> 0:05:07.280 shadow death does not in some sense derived from its 0:05:07.320 --> 0:05:09.919 usage in the Bible walk through the Valley of the 0:05:09.960 --> 0:05:12.240 Shadow of Death exactly. 0:05:12.760 --> 0:05:15.440 And of course we often use the term shadow as 0:05:15.480 --> 0:05:19.000 a verb to follow someone around and sort of learn 0:05:19.080 --> 0:05:22.159 from them, to shadow someone at work. Generally, when that 0:05:22.240 --> 0:05:25.920 is used, there are no haunting connotations, but shadow may 0:05:25.960 --> 0:05:29.919 also be a moral darkness or gloom now Brewers, Like 0:05:29.920 --> 0:05:32.560 I said, is also always great for some antiquated sayings. 0:05:33.640 --> 0:05:37.000 Here are a few examples gone to the bad for 0:05:37.080 --> 0:05:40.440 the shadow of an ass aka, choose your battles and 0:05:40.520 --> 0:05:43.000 don't battle for something as dumb as the shadow of 0:05:43.040 --> 0:05:43.560 a donkey? 0:05:44.240 --> 0:05:45.920 Does that go back to a story? I don't know. 0:05:46.520 --> 0:05:50.280 I have no additional context, but feel free to start 0:05:50.320 --> 0:05:55.320 incorporating it into your daily conversations, listeners. There's another one, 0:05:55.400 --> 0:05:58.719 May your shadow grow less? This one apparently has Eastern 0:05:58.760 --> 0:06:00.800 origins according to Brewers. And I'll get back to this 0:06:00.839 --> 0:06:02.880 one in a bit. And then the idea of being 0:06:02.960 --> 0:06:08.200 reduced to a shadow or emaciated, you know, so slender, 0:06:08.839 --> 0:06:13.400 so starved that even your shadow is reduced. But you know, 0:06:13.440 --> 0:06:16.160 obviously your shadow would be reduced if your body was reduced. 0:06:16.960 --> 0:06:19.680 But it's also not that simple, right, because shadows can 0:06:19.680 --> 0:06:22.960 be manipulated. We can cast a very long shadow depending 0:06:23.000 --> 0:06:26.320 on where we are in reference to the sun. Joe, 0:06:26.320 --> 0:06:28.800 I don't know about your experiences with this as a 0:06:28.920 --> 0:06:30.919 as a father, but I remember when my son was 0:06:30.960 --> 0:06:34.880 a mere toddler that we would have some fun with 0:06:34.960 --> 0:06:38.000 our own shadows in the park, especially in the way 0:06:38.040 --> 0:06:40.599 that a child can be shown to manipulate their own shadow, 0:06:40.640 --> 0:06:43.400 to cast a long shadow, to cast a big shadow, 0:06:43.760 --> 0:06:46.400 and also have it interact with other shadows, like have 0:06:46.560 --> 0:06:51.279 your shadow dinosaur hand, you know, bite another person's shadow, 0:06:51.320 --> 0:06:52.159 and that sort of thing. 0:06:53.320 --> 0:06:57.600 Yeah. I don't know how much consciousness my daughter has 0:06:57.640 --> 0:06:59.680 of her own shadow yet, but I have done some 0:06:59.720 --> 0:07:01.880 shadow puppet shows for her in the light of the 0:07:01.920 --> 0:07:05.440 setting sun, and it's interesting to watch because I think 0:07:05.520 --> 0:07:09.240 the few times I've done this, my daughter has tried 0:07:09.279 --> 0:07:12.080 to reach out and touch the shadow is projected on 0:07:12.160 --> 0:07:14.080 the floor or on the wall, but of course there's 0:07:14.120 --> 0:07:18.480 nothing to touch. But she perceives that this moving display 0:07:18.520 --> 0:07:20.760 of shapes must be some kind of object that she 0:07:21.520 --> 0:07:22.280 could grasp. 0:07:22.720 --> 0:07:26.600 Yeah, there's something about shadow. I think a child's fascination 0:07:26.720 --> 0:07:30.840 with them perhaps reveals much about what remains there, at 0:07:30.880 --> 0:07:32.880 least in some part of our mind. Even after we 0:07:32.920 --> 0:07:35.800 have grown accustomed to them, once they've become old hat, 0:07:36.640 --> 0:07:39.160 there are still going to be moments where we notice 0:07:39.160 --> 0:07:41.480 the peculiar when it comes to the shadow, that a 0:07:41.520 --> 0:07:45.000 shadow doesn't necessarily tell the truth. But also at the 0:07:45.000 --> 0:07:48.119 same time, a shadow can reveal things that are there 0:07:48.800 --> 0:07:50.920 that you know, perhaps you can't see an individual, but 0:07:50.960 --> 0:07:53.760 you can see their shadow, that sort of thing. So 0:07:53.800 --> 0:07:56.960 there's there's obviously a lot of rich room for interpretation. 0:07:57.920 --> 0:08:00.000 But then also just coming back to the linguistics of it, 0:08:00.040 --> 0:08:02.560 certainly when you get into translation. I know we were 0:08:02.560 --> 0:08:05.400 looking around for possible shadow poems to read at the 0:08:05.440 --> 0:08:07.800 top of this episode, and I was looking at some 0:08:07.880 --> 0:08:11.640 Borges poems in translation, of course, and for instance, there's 0:08:11.680 --> 0:08:14.400 one titled to the One who is Reading Me, which 0:08:14.440 --> 0:08:17.880 is a nice haunting poem with a number of different 0:08:17.880 --> 0:08:22.000 Borges sort of trademarks in it. But some translations will 0:08:22.080 --> 0:08:26.920 use shadow and others will not, So you know, it 0:08:26.960 --> 0:08:29.200 seems like a shadow. Maybe it is one of those 0:08:29.240 --> 0:08:31.240 words that, like we've been saying, it refers to so 0:08:31.280 --> 0:08:34.960 many things. It may be invoked in translation, even if 0:08:35.040 --> 0:08:38.680 that was perhaps not the author or the poet's original intent. 0:08:39.480 --> 0:08:42.880 Well, coming back to the representation of shadows in our minds, 0:08:42.960 --> 0:08:44.800 I dug up what I thought were a couple of 0:08:44.840 --> 0:08:50.040 pretty interesting cognitive science papers about shadow consciousness. So the 0:08:50.080 --> 0:08:52.640 first one I was looking at was a short paper 0:08:52.679 --> 0:08:55.800 published in Trendsing Cognitive Sciences in two thousand and six 0:08:55.920 --> 0:09:00.760 by Roberto Cassatti, an Italian professor. This paper is called 0:09:00.800 --> 0:09:05.000 the Cognitive Science of Holes and Cast Shadows, and this 0:09:05.160 --> 0:09:08.480 was published in two thousand and six. This paper asked 0:09:08.520 --> 0:09:13.480 an interesting question. It was what can quasi objects or 0:09:13.600 --> 0:09:18.160 negative objects such as shadows and holes tell us about 0:09:18.200 --> 0:09:23.320 how human brains perceive and understand physical objects. Of course, 0:09:23.559 --> 0:09:26.600 holes and cast shadows are interesting because they are not 0:09:26.960 --> 0:09:31.000 objects in themselves. They're actually just absences, in one case 0:09:31.440 --> 0:09:35.080 the absence of solid physical substance and in the other 0:09:35.440 --> 0:09:38.640 a relative absence of light. But despite the fact that 0:09:38.679 --> 0:09:43.080 things like holes and shadows are just absences, we intuitively 0:09:43.160 --> 0:09:48.120 often think of them as substances in themselves. Kasati writes, quote, 0:09:48.120 --> 0:09:52.680 both holes and cast shadows are dependent features. They cannot 0:09:52.720 --> 0:09:57.240 exist without objects hosting or casting them. Both shadows and 0:09:57.360 --> 0:10:01.400 holes are somewhere between being regions of space and fully 0:10:01.400 --> 0:10:05.680 fledged material objects. They are similar enough to bounded regions 0:10:05.720 --> 0:10:09.080 of space that they have a location, a shape, a size, 0:10:09.120 --> 0:10:12.880 and are as immaterial as space is, but are more 0:10:12.960 --> 0:10:16.440 object like as they can persist over time and move. 0:10:17.120 --> 0:10:21.360 And I think it's this ambiguity between being an object 0:10:21.520 --> 0:10:25.480 and not being an object that makes a shadow counterintuitive. 0:10:25.600 --> 0:10:28.800 One example I've seen is people talking about the interesting 0:10:28.840 --> 0:10:33.080 fact that a shadow could technically move faster than the 0:10:33.120 --> 0:10:36.640 speed of light. How would that be possible? The example 0:10:36.640 --> 0:10:39.760 would often be given that like, if you have a 0:10:39.920 --> 0:10:44.559 source of light that you can project across the entire 0:10:44.679 --> 0:10:47.080 surface of a planet, maybe the surface of the moon, 0:10:47.679 --> 0:10:51.120 and then you, standing right next to that source of light, 0:10:51.600 --> 0:10:54.400 move your finger quickly in front of it, you could 0:10:54.440 --> 0:10:58.200 actually make your shadow travel across the surface of that 0:10:58.320 --> 0:11:02.200 distant object fast than light would be able to travel 0:11:02.240 --> 0:11:04.480 if it were going from one side of that object 0:11:04.559 --> 0:11:07.559 to the other, though of course, nothing is actually traveling 0:11:07.600 --> 0:11:09.800 in the case of how you're altering the shadow there. 0:11:09.840 --> 0:11:13.320 So it's not actually a violation of the laws of physics. 0:11:13.360 --> 0:11:16.280 It's not any object going faster than the speed of light, 0:11:16.600 --> 0:11:21.040 but is it is a change propagating through space in 0:11:21.080 --> 0:11:24.040 some sense from our perspective, faster than the speed of light. 0:11:25.120 --> 0:11:29.800 Interesting, So absence in a sense travels faster than anything material. 0:11:30.280 --> 0:11:32.440 So I wanted to bring up a couple things mentioned 0:11:32.440 --> 0:11:35.360 in this paper that start me as interesting. One of 0:11:35.360 --> 0:11:38.880 them is a reference to another paper published a couple 0:11:38.880 --> 0:11:43.120 of years before this in the journal Perception called Impossible 0:11:43.160 --> 0:11:49.240 Shadows and the Shadow Correspondence Problem by Pascal Mammasian published 0:11:49.280 --> 0:11:51.720 in two thousand and four. And the background on this 0:11:51.800 --> 0:11:55.680 paper is the observation that we can and do use 0:11:55.760 --> 0:11:59.160 shadows to estimate information about a scene. So we can 0:11:59.240 --> 0:12:03.120 use shadows to infer properties of both the light source 0:12:03.200 --> 0:12:05.200 where light is coming from and a scene we're looking 0:12:05.240 --> 0:12:09.880 at and the object casting the shadow. But getting information 0:12:10.040 --> 0:12:14.760 this way is not a computationally trivial task. It's actually 0:12:14.800 --> 0:12:20.000 somewhat difficult Mamasian rights quote. In order to use that information, 0:12:20.040 --> 0:12:23.640 our visual system has first to segment regions in the image, 0:12:23.760 --> 0:12:27.360 decide that these regions are potential shadows rather than say 0:12:27.520 --> 0:12:31.680 ink blots, and then match these shadow candidates with objects 0:12:31.720 --> 0:12:34.840 in the scene. We call this last processing stage the 0:12:35.040 --> 0:12:39.680 shadow correspondence problem. It is reminiscent of the correspondence problem 0:12:39.760 --> 0:12:44.080 in stereopsis, and stereopsis is how the brain infers depth 0:12:44.200 --> 0:12:47.080 in our vision by comparing the images produced by our 0:12:47.080 --> 0:12:51.360 two different eyes and then going on they say quote 0:12:51.600 --> 0:12:54.920 or motion perception, where one has to match features between 0:12:54.960 --> 0:12:58.400 the left and right images, or between consecutive frames of 0:12:58.440 --> 0:13:02.960 a movie. So in inferring real accurate information about a 0:13:03.000 --> 0:13:05.520 scene you're looking at in a photograph or in front 0:13:05.559 --> 0:13:10.360 of you based on shadows is computationally intensive. We use 0:13:10.400 --> 0:13:13.320 shadows to get information, but it's a complex problem with 0:13:13.440 --> 0:13:16.760 multiple variables, and it's taxing on the brain. And so 0:13:16.840 --> 0:13:19.920 the author of this paper describes some experiments leading to 0:13:19.960 --> 0:13:24.280 the conclusion that we actually only infer information from shadows 0:13:24.360 --> 0:13:28.240 using a rough system. And one piece of evidence for 0:13:28.280 --> 0:13:32.200 that is that people usually seemed not to notice when 0:13:32.280 --> 0:13:36.600 projected shadows put in front of them were physically impossible. 0:13:37.160 --> 0:13:39.280 Rob I'd like, I've got an illustration for you to 0:13:39.280 --> 0:13:41.160 look at here that I pulled out of this paper. 0:13:41.679 --> 0:13:45.320 So there are a series of six objects shown that 0:13:45.360 --> 0:13:49.079 are there are ray white to sort of like pole 0:13:49.200 --> 0:13:51.920 with an arm at the top, and then a shadow 0:13:52.040 --> 0:13:55.319 being cast by that object, and so you could try 0:13:55.360 --> 0:13:59.720 to infer some information about where the source of light 0:13:59.880 --> 0:14:03.880 is is in relation to this object. But four of 0:14:03.920 --> 0:14:07.160 these are possible shadows that could be cast by an 0:14:07.200 --> 0:14:11.120 object of the shape, and two of them are impossible shadows. 0:14:11.720 --> 0:14:16.280 Wow. So just looking at these six images here is 0:14:16.760 --> 0:14:20.080 it is a little taxing. It can feel the mental 0:14:20.120 --> 0:14:24.800 strain because you know, I'm instantly trying to imagine light 0:14:26.240 --> 0:14:30.640 approaching the object from different directions at different angles. And 0:14:31.200 --> 0:14:34.080 when I start sort of doing that three dimensional computation 0:14:34.160 --> 0:14:36.800 in my head, I mean, it seems like all of 0:14:36.800 --> 0:14:39.320 them are probable, Like none of them are really standing 0:14:39.320 --> 0:14:46.040 out to me as necessarily impossible. I don't know, maybe gosh, 0:14:46.120 --> 0:14:51.000 I don't know, maybe number two. Oh yeah, two is 0:14:51.040 --> 0:14:52.880 the only one that I'm that I'm thinking is even 0:14:52.920 --> 0:14:55.720 just a little bit suspect here. But yeah, this is 0:14:55.760 --> 0:14:57.960 this is this is this is rough to think about. 0:14:58.320 --> 0:15:01.400 You're in the same situation as most of the people 0:15:01.440 --> 0:15:04.320 who participated in this experiment, So most of the shadows 0:15:04.360 --> 0:15:07.320 given here are possible given the correct light source position, 0:15:07.880 --> 0:15:10.200 but the two on the right side of the image 0:15:10.240 --> 0:15:13.280 are impossible. If you look at them, you can see 0:15:13.280 --> 0:15:15.720 that the arm of the figure is pointed the wrong 0:15:15.800 --> 0:15:17.680 way in both of those cases. 0:15:18.160 --> 0:15:20.720 Fascinating. I guess this is why I've always been so 0:15:20.800 --> 0:15:23.880 forgiving too with video games, especially the ones where you 0:15:23.920 --> 0:15:26.960 could choose whether you wanted complex shadows or just sort 0:15:26.960 --> 0:15:30.120 of like the circle shadow. Like circle shadows good enough. 0:15:30.720 --> 0:15:33.400 If I'm having any kind of system issues, let's just 0:15:33.440 --> 0:15:34.520 go with this simple shadow. 0:15:35.080 --> 0:15:36.960 That might be a good instinct. We'll get to some 0:15:37.000 --> 0:15:39.240 reasoning about that in a second. So a couple of 0:15:39.280 --> 0:15:42.560 these images are not possible shadows. But I think I 0:15:42.640 --> 0:15:44.840 don't know. I already knew that I've read about it 0:15:44.880 --> 0:15:46.920 before I looked at the image, so I can't really 0:15:47.000 --> 0:15:49.160 know what my reaction would be. But you had the 0:15:49.160 --> 0:15:51.200 same reaction a lot of the people in the study did. 0:15:51.240 --> 0:15:54.280 They just didn't notice. People seemed not to notice that 0:15:54.320 --> 0:15:57.239 these shadows were not possible. It had to be explained 0:15:57.240 --> 0:16:01.760 to them afterwards by the experimenters, And so they used 0:16:01.960 --> 0:16:06.760 these bits of impossible geometry to infer mundane information about 0:16:06.800 --> 0:16:10.640 physical objects, space and light sources just like normal. So 0:16:10.680 --> 0:16:12.640 in the end here the author says that this is 0:16:12.680 --> 0:16:17.160 evidence that our brains use a quick mechanism or what 0:16:17.280 --> 0:16:21.440 is called a quote coarse representation course meaning rough, to 0:16:21.520 --> 0:16:25.080 solve the shadow correspondence problem. And another thing that gets 0:16:25.080 --> 0:16:28.720 pointed out in the discussion is surrealist art that makes 0:16:28.840 --> 0:16:33.400 use of impossible shadows. There is a painting called Indefinite 0:16:33.520 --> 0:16:38.080 Divisibility by a painter named Eve Tongi. Again that's called 0:16:38.160 --> 0:16:41.120 Indefinite Divisibility if you want to look it up yourself. 0:16:41.160 --> 0:16:45.000 It is a sort of dolliesque surreal painting with these 0:16:45.040 --> 0:16:48.680 strange objects standing up in a landscape with very stark, 0:16:50.120 --> 0:16:55.200 high contrast shadows that are falling long across the fading background. 0:16:55.280 --> 0:16:58.080 So there seems to be a strong directionally oriented source 0:16:58.080 --> 0:17:01.240 of light sort of where where the observer would be 0:17:01.360 --> 0:17:04.760 casting these long shadows. But in this paper there is 0:17:04.800 --> 0:17:08.359 a zoom in and some lines you can see if 0:17:08.400 --> 0:17:10.760 you scroll down in our outline here rob showing that 0:17:10.800 --> 0:17:14.040 the shadows cast in this painting are again impossible. They 0:17:14.080 --> 0:17:16.480 don't line up the way they would if there were 0:17:16.600 --> 0:17:19.040 actually a single consistent point of light. 0:17:19.880 --> 0:17:22.320 Yeah, this is fascinating. Yeah, once you start looking at 0:17:22.320 --> 0:17:25.040 it and really comparing object to shadow, then yeah, you 0:17:25.080 --> 0:17:26.720 start seeing hit the problems here. 0:17:26.880 --> 0:17:29.840 And yet I wouldn't have noticed at all. So this 0:17:30.040 --> 0:17:33.639 raises a question like, were the impossible shadows in this 0:17:33.760 --> 0:17:37.880 painting included simply by accident because most people wouldn't notice, 0:17:38.520 --> 0:17:41.879 or is it an intended surreal effect to I don't know, 0:17:42.040 --> 0:17:45.639 reward careful study of the painting for you to realize like, 0:17:45.680 --> 0:17:47.960 oh wait a minute, this is not physically possible. 0:17:49.000 --> 0:17:51.480 Hm, it's got to be the latter, right, I mean, 0:17:51.560 --> 0:17:54.320 it seems like the amount of work that would go 0:17:54.359 --> 0:17:57.399 into a piece like this, and being a surrealist piece, 0:17:57.480 --> 0:18:00.760 that would that would make sense to intentionally distory the shadows, 0:18:01.040 --> 0:18:03.159 even if it was done in such a way that 0:18:03.960 --> 0:18:06.200 many viewers of the painting would not notice. 0:18:06.600 --> 0:18:09.359 Okay, so short story there. We do use shadows to 0:18:09.480 --> 0:18:12.960 get relevant information about a scene we're looking at, but 0:18:13.400 --> 0:18:16.240 we only look so close because we apparently do not 0:18:16.640 --> 0:18:21.760 detect when when shadows violate the laws of physics or geometry. However, 0:18:21.840 --> 0:18:25.480 coming back to that paper I mentioned by Kassati, shadows also, 0:18:25.680 --> 0:18:30.240 in addition to providing relevant information, they also represent noise. 0:18:30.920 --> 0:18:33.879 We might not think about this often, but in reality, 0:18:34.000 --> 0:18:37.919 it would be quite easy to mistake a shadow for 0:18:38.040 --> 0:18:41.920 a physical object or the outline of such to interpret, 0:18:41.960 --> 0:18:45.520 to misinterpret a shadow falling across an object as a 0:18:45.680 --> 0:18:50.800 contour on that object and the and Kassati points out 0:18:50.840 --> 0:18:53.639 this is one reason it is so difficult to represent 0:18:53.760 --> 0:18:59.080 shadows in line drawings. So Kassati says, our brains deal 0:18:59.160 --> 0:19:02.919 with this noise threat by mostly tuning out shadows as 0:19:03.000 --> 0:19:07.160 visual representations unless we suddenly decide to focus on them. 0:19:07.800 --> 0:19:10.200 And that seemed very true to me. You know, we 0:19:11.600 --> 0:19:15.720 see shadows all the time. We are constantly surrounded by shadows, 0:19:16.760 --> 0:19:20.680 but our brain sort of makes them cognitively invisible unless 0:19:20.680 --> 0:19:23.840 we decide for some reason to focus on them. And 0:19:23.920 --> 0:19:28.080 Cassatti calls this having quote limited conscious access to shadows. 0:19:28.720 --> 0:19:31.919 Yeah, this is fascinating. So there is data there in 0:19:31.960 --> 0:19:35.520 the shadow, but there's just too much noise really to 0:19:35.640 --> 0:19:39.040 depend on it too heavily, and there's ultimately better visual 0:19:39.080 --> 0:19:41.560 and other sense data to go off of in any 0:19:41.560 --> 0:19:43.880 given situation that involves a shadow, I'm assuming. 0:19:44.280 --> 0:19:47.399 So yeah, I found that really interesting that as a 0:19:47.480 --> 0:19:51.679 form of visual information, shadows exist in this middle realm 0:19:51.720 --> 0:19:55.600 where we can get useful information from them. But we're 0:19:55.680 --> 0:19:59.000 never looking too close, or at least not naturally unless 0:19:59.000 --> 0:20:01.560 we're like really forced, because a lot of times we 0:20:01.600 --> 0:20:04.879 don't even notice if the shadow is eldritch in nature, 0:20:04.920 --> 0:20:08.120 it's doing something geometry can't do or wouldn't be justified 0:20:08.119 --> 0:20:11.600 by how light works. But secondarily, most of the time, 0:20:11.720 --> 0:20:14.800 even though we're looking right at shadows, we don't see them. 0:20:14.800 --> 0:20:17.440 I mean, I'm literally looking right at shadows right now, 0:20:17.760 --> 0:20:21.560 and I don't see them as shadows unless I notice 0:20:21.640 --> 0:20:25.480 to look at the shadows there there. They don't. They 0:20:25.480 --> 0:20:28.879 don't I don't know strike my visual system as relevant, 0:20:29.040 --> 0:20:31.080 and so I'm just like I tune them out. 0:20:31.640 --> 0:20:35.800 That's interesting. Yeah, we kind of have shadow blindness to 0:20:35.960 --> 0:20:38.640 a large degree, which I guess makes it even more 0:20:38.680 --> 0:20:42.320 fascinating to think that there might be other beings out 0:20:42.320 --> 0:20:46.600 there who can see shadows in ways it can appreciate 0:20:46.640 --> 0:20:59.720 shadows in ways that human beings cannot. I would like 0:20:59.800 --> 0:21:06.400 to at this point turn our attention to various fictional, legendary, folkloric, 0:21:06.480 --> 0:21:13.080 and literary examples of shadowless wizards, demons, and vampires, and 0:21:13.200 --> 0:21:15.960 much more. In the shadows that may or may not 0:21:16.000 --> 0:21:19.840 be cast by these various individuals. So I've mentioned my 0:21:19.880 --> 0:21:23.439 fondness for the horror fantasy of Weird Tales era author 0:21:23.520 --> 0:21:26.680 Clark Ashton Smith before, and one of my all time 0:21:26.720 --> 0:21:30.080 favorites is a short story titled The Double Shadow about 0:21:30.080 --> 0:21:32.919 a pair of wizards who unearthed ancient dark magic that 0:21:33.000 --> 0:21:36.400 in turn dooms them both to a horrible death. Smith's 0:21:36.400 --> 0:21:40.000 own summary of the tale via eldrich Dark dot com, 0:21:40.040 --> 0:21:41.840 which is a great website that has just all of 0:21:41.840 --> 0:21:47.000 his writings available. This is how the author himself summarized it. Quote. 0:21:47.040 --> 0:21:49.840 A man sees a monstrous shadow following his own and 0:21:49.920 --> 0:21:53.480 merging with it gradually day by day, while coincidentally with 0:21:53.560 --> 0:21:56.920 this merging, he loses his own entity and becomes possessed 0:21:56.920 --> 0:22:00.000 by an evil thing from unknown worlds in his personality. 0:22:00.200 --> 0:22:03.840 The hideous invading spirit takes form and becomes manifest till 0:22:03.880 --> 0:22:09.720 his shadow is that which had followed him. And the 0:22:09.760 --> 0:22:13.640 story itself is very haunting and the ending is really awesome, 0:22:13.640 --> 0:22:17.000 with the doomed Wizard, the last of the doomed wizards, 0:22:17.040 --> 0:22:21.200 writing his last personal testimony in a locked study, while 0:22:22.160 --> 0:22:28.320 while this monstrous shadow crawls, ever closer closes as follows, So, 0:22:28.520 --> 0:22:31.040 knowing that the time is brief, I have shut myself 0:22:31.080 --> 0:22:33.919 in the room of volumes and books and have written 0:22:33.960 --> 0:22:37.400 this account. And I have taken the bright triangular tablet, 0:22:37.680 --> 0:22:40.640 whose solution was our undoing, and have cast it from 0:22:40.680 --> 0:22:43.639 the window into the sea, hoping that none will find 0:22:43.680 --> 0:22:46.880 it after us. And now I must make an end 0:22:47.240 --> 0:22:50.800 and enclose this writing in the sealed cylinder of our callum, 0:22:51.320 --> 0:22:54.159 and fling it forth to drift upon the wave. For 0:22:54.240 --> 0:22:56.800 the space between my shadow and the shadow of the 0:22:56.880 --> 0:23:01.840 horror is strained momently, and the space is no wider 0:23:02.119 --> 0:23:06.440 than the thickness of a wizard's pen. Now, I had 0:23:06.520 --> 0:23:10.080 long thought that this was mere fantastic invention on Smith's part, 0:23:10.960 --> 0:23:13.520 And then that and it doesn't just detract it all 0:23:13.560 --> 0:23:16.240 from the success of the story and the effect of 0:23:16.280 --> 0:23:20.240 the story. But based on what I was reading in Brewers, 0:23:20.520 --> 0:23:23.640 it would seem that he may have based this detail 0:23:23.720 --> 0:23:26.440 on the the that that example of so called Eastern 0:23:26.480 --> 0:23:30.840 origin this is. This is of course spectacularly vague and 0:23:30.840 --> 0:23:33.520 hartly limits the search too much. It just means that 0:23:33.640 --> 0:23:38.280 it must have originated outside of ancient Greece, Ancient Rome, 0:23:38.359 --> 0:23:42.000 and European traditions. But the idea is explained in Brewers 0:23:42.359 --> 0:23:45.800 is that wizards studying the Black Arts, after they reach 0:23:45.840 --> 0:23:49.280