WEBVTT - SYSK Selects: How Mirrors Work 0:00:01.040 --> 0:00:04.120 Good afternoon, and welcome to Stuff you Should Know Selects. 0:00:04.600 --> 0:00:06.520 It is Charles W. Chuck Bryant here in. My pick 0:00:06.600 --> 0:00:10.119 for this week is How Mirrors Work from September fourteen, 0:00:10.480 --> 0:00:13.960 two thousand ten. And boy, this one was a tough one. 0:00:14.200 --> 0:00:16.560 I remember when we had the idea of doing a 0:00:16.560 --> 0:00:18.799 show on mirrors. I thought, well, that's going to be 0:00:18.800 --> 0:00:21.840 short and not so interesting. But then I thought, oh, 0:00:21.840 --> 0:00:24.880 wait a minute, how do mirrors work? How are those 0:00:24.920 --> 0:00:28.320 things made? Where did they come from? It's pretty amazing. 0:00:28.400 --> 0:00:31.840 So we get into all that and more, and it's 0:00:31.880 --> 0:00:34.600 a pretty fascinating episode. And this will be one where 0:00:34.640 --> 0:00:36.480 you can kind of whip out some of these facts 0:00:36.720 --> 0:00:39.479 at your next dinner party and amazing to light your 0:00:39.479 --> 0:00:42.720 friends and family. So enjoy How Mirrors Work right here, 0:00:42.840 --> 0:00:54.760 right now. Welcome to Stuff you Should Know from House 0:00:54.760 --> 0:01:03.440 Stuff Works dot com. Hey, and welcome to the podcast. 0:01:03.720 --> 0:01:07.280 I'm Josh Clark, there's Charles W. Chuck Bryant. We're about 0:01:07.319 --> 0:01:10.960 to talk about mirrors. I set up it's a sinct 0:01:11.840 --> 0:01:13.960 how are you were you in the mirrors growing up? 0:01:14.080 --> 0:01:16.640 Now that we said, you know, I did it scinctly, 0:01:16.640 --> 0:01:21.319 we're gonna just blow like three minutes right. No, I 0:01:21.319 --> 0:01:23.120 was asking you if you were into mirrors, in the 0:01:23.240 --> 0:01:25.800 mirrors growing up? Yeah, I mean that didn't every kid 0:01:25.840 --> 0:01:28.240 go through a phase where they're like very obsessed with 0:01:28.280 --> 0:01:30.640 their looks and mirrors and things. Oh yeah, I was 0:01:30.680 --> 0:01:32.920 into myself. I wasn't in the mirrors. They were just 0:01:33.319 --> 0:01:36.319 a means and end, you know. Yeah, But I like 0:01:36.360 --> 0:01:37.720 I was reading this and I kind of was just 0:01:37.760 --> 0:01:40.440 thinking myself and remembering laughing about I remember being like 0:01:40.480 --> 0:01:43.759 fifteen and like stopping to look at mirrors anytime there 0:01:43.840 --> 0:01:46.360 was one to what looked like Yeah, and now I 0:01:46.440 --> 0:01:49.200 just I break them. I'd forgotten all about that phase 0:01:49.240 --> 0:01:51.040 of my life though, until you just brought it up. 0:01:51.240 --> 0:01:54.120 Remember that. Yeah, it's nice to be able to not 0:01:54.280 --> 0:01:56.240 look at a mirror. Like some days I'll go out, 0:01:56.920 --> 0:01:58.960 you know, after getting ready in the morning, and I 0:01:59.000 --> 0:02:02.000 have no idea what I actually look like. But I'm 0:02:02.080 --> 0:02:04.880 so And this is um this cross pollination with an 0:02:04.920 --> 0:02:09.760 earlier podcast. I suffered from body dysmorphic disorder so badly 0:02:10.280 --> 0:02:12.440 that I don't really know what I look like anyway. 0:02:12.600 --> 0:02:14.440 What do you think you look like? I think I 0:02:14.560 --> 0:02:19.880 look a bit like the top from Taxidermia. I what's 0:02:19.919 --> 0:02:24.679 that it's not plusant? Okay, well you don't my friend. 0:02:24.680 --> 0:02:25.880 I don't even know what he looks like, but I 0:02:25.919 --> 0:02:29.200 can tell you don't look like him. I appreciate that, Chuck, Chuck, 0:02:29.720 --> 0:02:32.160 do you want to hear what I had in store? Like? 0:02:32.200 --> 0:02:34.040 I could not come up with an intro for this. 0:02:34.200 --> 0:02:40.079 Let's hear it. Websters defines mirror. I'm kidding. I always 0:02:40.080 --> 0:02:42.440 going to say something equally bad, though, It's going to 0:02:42.440 --> 0:02:46.760 be something along the lines with mirrors are ubiquitous. I've 0:02:46.800 --> 0:02:50.840 seen at least six of them today. They weren't always 0:02:50.840 --> 0:02:53.200 that way, though, Chuck. Well, it says in the article 0:02:53.240 --> 0:02:56.880 here the full length mirrors have only been around four years. 0:02:56.880 --> 0:02:59.919 That didn't seem right. That's not right. No, um full 0:03:00.040 --> 0:03:03.520 length mirrors. There is a type of full length mirror 0:03:03.720 --> 0:03:07.200 um that has been around for about four years. Full 0:03:07.280 --> 0:03:09.880 length mirrors, as far as I know, are mirrors capable 0:03:10.280 --> 0:03:13.359 of reflecting a full image of a person, have been 0:03:13.400 --> 0:03:16.840 around since about the first century A d actually um 0:03:16.919 --> 0:03:23.720 and mirrors us using surfaces polished surfaces to see our 0:03:23.760 --> 0:03:29.560 own reflection. Um has been around since about six thousand BC. Yeah, 0:03:29.639 --> 0:03:33.639 the earliest ones were found in Anatolia, Turkey and they're 0:03:33.680 --> 0:03:37.600 polished subsidian. Yeah, it's a volcanic glass. Yeah, so it's 0:03:37.640 --> 0:03:40.720 it's dark, this interesting, but it's still produced the best reflection, 0:03:40.760 --> 0:03:42.720 I guess at the time. At the time, yeah, I 0:03:42.760 --> 0:03:44.480 mean you gotta you gotta go with what you what 0:03:44.600 --> 0:03:46.720 we have to work with, right. Well yeah, but then 0:03:46.760 --> 0:03:50.160 after that they led them to um like silver and 0:03:50.360 --> 0:03:54.400 bronze and copper, polished polished reflections basically, And Chuck, I 0:03:54.440 --> 0:03:56.920 don't know if you've ever held a hunk of of 0:03:57.040 --> 0:04:02.760 copper or bronze I haven't, or silver I have. Okay, 0:04:02.760 --> 0:04:05.680 it's heavy, Yeah, it's real heavy. Right. So this actually 0:04:05.720 --> 0:04:10.680 limited the size of mirrors for centuries, right Yeah. And 0:04:10.680 --> 0:04:12.400 they were just kind of decorative at first, two right, 0:04:12.960 --> 0:04:15.440 I think so. And you also had to be extremely rich, 0:04:15.760 --> 0:04:19.400 um to own one of these, right, um. And then 0:04:19.560 --> 0:04:23.520 around I think the Middle Ages, we became capable of 0:04:23.520 --> 0:04:26.080 making glass, and all of a sudden, it was like 0:04:26.200 --> 0:04:30.120 mirror technology just takes a huge leap forward. Well true, 0:04:30.320 --> 0:04:34.640 but not not super uh forward, because the sand was 0:04:34.920 --> 0:04:37.440 pretty impure back then they used to make the glass. 0:04:37.480 --> 0:04:39.920 So I think they, um they said in the article, 0:04:40.000 --> 0:04:42.400 was until like the Renaissance that it kind of really 0:04:42.440 --> 0:04:46.000 started becoming a little more polished, if you will, terrible. 0:04:46.120 --> 0:04:49.120 And then the Venetians are who really you know with 0:04:49.160 --> 0:04:51.039 a glass and everything. They just they just took in 0:04:51.120 --> 0:04:53.840 ran with it. Well. Even still, if you successfully made 0:04:53.839 --> 0:04:58.800 a mirror UM, it was probably extremely expensive as well 0:04:59.320 --> 0:05:02.560 because they were so rare. The process of manufacturing a 0:05:02.640 --> 0:05:06.960 mirror UM very infrequently produced a usable mirror. That's what 0:05:07.000 --> 0:05:15.280 you're doing was adhering um melted molten metal onto glass, 0:05:15.560 --> 0:05:19.040 which almost always broke the glass. So when it didn't, 0:05:19.080 --> 0:05:21.400 I'm sure you're just like, oh my god's the first 0:05:21.400 --> 0:05:26.159 one in seven years? Right? Um? But that when I 0:05:26.200 --> 0:05:28.039 was reading this article, I didn't really think about it. 0:05:28.120 --> 0:05:30.600 That's what a mirror is, isn't it. I've even seen 0:05:30.640 --> 0:05:33.760 the back of mirrors and been like others like metal 0:05:34.080 --> 0:05:36.880 looks like spray painted on the back. That's exactly right. 0:05:37.320 --> 0:05:39.799 And that was a process um what's it called silver 0:05:39.920 --> 0:05:43.520 ring that was invented by a guy named Justice von 0:05:43.640 --> 0:05:47.800 Liebig and in eighteen thirty five, if he figured out 0:05:47.880 --> 0:05:52.280 how to spray very thin layer of silver um or 0:05:52.320 --> 0:05:55.479 aluminum on the back or on one side of a 0:05:55.640 --> 0:05:59.560 glass and they're my friend. You have the modern mirror. Yeah, 0:05:59.600 --> 0:06:01.240 and now that I think they make it now by 0:06:01.320 --> 0:06:04.080 heating aluminum in a vacuum in kind of much the 0:06:04.120 --> 0:06:07.240 same way or different methods, but the same same concept. 0:06:08.680 --> 0:06:11.560 Go ahead, Well, I wanted to say when when you 0:06:11.600 --> 0:06:15.680 were talking about the Renaissance, the Venetians were they, I 0:06:15.720 --> 0:06:19.159 guess they had the secret of mirrors under wraps like 0:06:19.200 --> 0:06:23.880 the Mason's very much so. Um. And if you were 0:06:24.120 --> 0:06:27.120 a mirror maker and it got out that you had 0:06:27.240 --> 0:06:32.200 told someone how to make mirrors, you were frequently killed, right, yeah, 0:06:32.520 --> 0:06:36.600 trade secret. But when mirrors were introduced, um, when good 0:06:36.640 --> 0:06:40.480 mirrors were introduced, not polished subsidian, things changed a little bit, 0:06:40.600 --> 0:06:43.440 especially with art. Right Yeah, I never really considered that, 0:06:43.480 --> 0:06:46.520 but that it spawned something that would become a hallmark 0:06:46.560 --> 0:06:49.240 of the art world, which is the self portrait. Right 0:06:49.320 --> 0:06:51.800 before that, you couldn't draw yourself because you could not 0:06:51.880 --> 0:06:55.359 see yourself. That's exactly right, And you could, but I 0:06:55.360 --> 0:06:58.040 mean you're gonna use like maybe a pond or well, 0:06:58.480 --> 0:07:00.760 piece of polished medal or something like that. Imagine like 0:07:01.440 --> 0:07:03.240 going out and looking at a pond and going back 0:07:03.240 --> 0:07:04.760 and sitting down that I was opposed to having a 0:07:04.760 --> 0:07:08.679 mirror there. Yes, really simplified it. It's also not coincidental 0:07:08.839 --> 0:07:12.840 that UM good mirrors came about at the same time 0:07:12.840 --> 0:07:17.760 that UM linear perspective was introduced into art. What. Yeah, 0:07:17.840 --> 0:07:23.920 there's a guy named um Filippo Brunus Bruno LLESHI nice, Chuck, 0:07:24.000 --> 0:07:27.280 thank you for doing that, UM, and he he I 0:07:27.280 --> 0:07:30.160 guess discovered linear perspective because I think it's one of 0:07:30.240 --> 0:07:32.960 the things that was always there. We just stumbled upon 0:07:33.000 --> 0:07:36.440 it through mirrors. That's how we figured it out. Yeah, 0:07:36.440 --> 0:07:38.320 because if you look at a mirror, all of a sudden, 0:07:38.600 --> 0:07:42.800 linear perspective really comes into focus, right you will. Well. 0:07:42.840 --> 0:07:45.880 And then scientists UM said hey, we could use these 0:07:45.920 --> 0:07:49.360 to make like reflecting telescopes, and that was what year 0:07:49.440 --> 0:07:51.840 was at. That was a long time ago. The first 0:07:51.840 --> 0:07:55.960 reflecting telescope was invented by a guy named James Bradley 0:07:56.440 --> 0:07:59.440 just off the top of my head. Very well done. Uh, 0:07:59.480 --> 0:08:03.000 And the mirrors were also used by a very very 0:08:03.040 --> 0:08:07.560 famous scientist early scientists named Archimedes. Supposedly, Yeah, I wrote 0:08:07.560 --> 0:08:10.720 an article on archimedes death. Ray. Oh did you write that? Yeah? 0:08:10.760 --> 0:08:12.800 Did you ever read it? I did back in a 0:08:12.840 --> 0:08:15.280 while ago. Just out of interest, how about that? Thanks 0:08:15.280 --> 0:08:17.640 a lot man. Sure did you see in it? Um? 0:08:17.800 --> 0:08:20.160 Some I can't remember. It was one of the Ivy 0:08:20.240 --> 0:08:23.440 League schools. They tried to set things on fire with 0:08:23.560 --> 0:08:26.840 this system of mirrors. That archie, that's who it was, 0:08:27.000 --> 0:08:31.880 and they succeeded. Yes, And the MythBusters claimed it was busted, 0:08:31.920 --> 0:08:34.439 like they set a small fire. But I think they 0:08:34.440 --> 0:08:36.480 busted it because they said it wasn't enough to like 0:08:37.400 --> 0:08:39.600 sink a ship. But m I T I mean, they 0:08:39.800 --> 0:08:42.720 caused quite a fire on that boat, and of course 0:08:42.760 --> 0:08:44.800 they had. I mean I saw this set up online today. 0:08:44.800 --> 0:08:47.240 It was pretty massive. I don't know if Archimedes had 0:08:47.320 --> 0:08:50.400 that kind of technology or at least that many mirrors 0:08:50.400 --> 0:08:52.800 at its disposal, or maybe he did, and plus they 0:08:52.840 --> 0:08:55.280 had I think they used pretty good mirrors too. Yeah, 0:08:55.320 --> 0:08:56.800 well it was legend though. They don't know if the 0:08:56.840 --> 0:08:59.800 Archimedes sing is true. Right. We know that he invented 0:08:59.840 --> 0:09:02.640 the water screw and let's save countless lives. What's that 0:09:03.320 --> 0:09:07.440 It's a way to deliver water from the ground top side. 0:09:07.559 --> 0:09:10.400 Oh really yeah cool? You have to check it out, 0:09:10.440 --> 0:09:15.079 smart dude. Um so chuck, We now know the comprehensive 0:09:15.920 --> 0:09:19.680 broad strokes of the history of mirrors. Right, Yes, let's 0:09:19.679 --> 0:09:22.199 talk about mirror physics. We work for how Stuff Works 0:09:22.240 --> 0:09:25.680 dot com, which means we're pretty much obligated to discuss 0:09:25.720 --> 0:09:28.600 the physics of whatever we're talking about any time it applies, right, 0:09:28.600 --> 0:09:32.679 And that's true, and mirrors are definitely one of those times. Yes, 0:09:33.040 --> 0:09:35.599 So Chuck take it away. Well, I can cover the 0:09:35.640 --> 0:09:37.800 first part because it makes sense to me. The law 0:09:37.840 --> 0:09:40.880 of reflection um Josh says that when you bounce array 0:09:40.920 --> 0:09:43.280 of light off the surface, it bounces back off in 0:09:43.320 --> 0:09:46.800 a certain way, and it is um the angle of 0:09:46.840 --> 0:09:50.120 incidences is when it comes in the angle of reflection. 0:09:50.120 --> 0:09:53.480 It when it bounces off, and it matches so that 0:09:53.559 --> 0:09:55.560 the way they pointed out in the article, which makes 0:09:55.600 --> 0:09:57.839 sense to me, is like at sunset, the sun is 0:09:57.920 --> 0:09:59.960 very low on the horizon, so it bounces off at 0:10:00.000 --> 0:10:03.079 a low angle, or approaches the water at a low angle, 0:10:03.120 --> 0:10:05.360 like at a lake. Let's say, then it bounces off 0:10:05.400 --> 0:10:07.120 of that lake at the same low angle, like right 0:10:07.120 --> 0:10:09.520 into your face. Right, But if it seems brighter, if 0:10:09.559 --> 0:10:13.840 the sun's overhead though, the sunlight is coming down under 0:10:13.880 --> 0:10:16.800 the lake and it's reflecting back up basically over your head. 0:10:17.760 --> 0:10:23.199 You're looking at a horizontal angle pretty much, and this 0:10:23.280 --> 0:10:26.640 is happening on a vertical angle. Yeah, that's why you'll 0:10:26.640 --> 0:10:30.920 get like more glare at a sunrise or a sunset scenario. Um. 0:10:31.000 --> 0:10:33.480 And what you're saying, the angle of incidence equals the 0:10:33.520 --> 0:10:37.120 angle of reflection. Right. Indeed, if you take if a 0:10:37.679 --> 0:10:40.400 if a beam of light is shot at a ninety 0:10:40.400 --> 0:10:43.520 degree angle or no, let's say eighty degree angle, it's 0:10:43.559 --> 0:10:45.960 going to bounce off at an opposite eighty degree angle. 0:10:46.400 --> 0:10:48.800 So both are at eighty degrees. But if you look 0:10:48.800 --> 0:10:51.719 at the whole thing, the incidents and the reflection, it's 0:10:51.760 --> 0:10:54.920 going to cover a hundred and sixty degrees right right, 0:11:19.240 --> 0:11:21.079 all right, So that's the first part. That's that's how 0:11:21.640 --> 0:11:24.640 that explains how light reacts with with reflection, and that's 0:11:24.640 --> 0:11:27.720 where the smooth surface with with most things like say, 0:11:28.040 --> 0:11:32.560 look at my hand man, Take a look at these hands, um, 0:11:32.640 --> 0:11:35.559 the the light that's bouncing off of them. What's giving 0:11:35.640 --> 0:11:39.800 us the ability to see these huge, awesome hands, um, 0:11:41.160 --> 0:11:45.920 is they're not huge. Are they are smaller than average size? No, 0:11:46.040 --> 0:11:48.360 they're they're bigger than mine. I got small hands. I 0:11:48.400 --> 0:11:51.000 wouldn't see you have small hands. Let's see now those 0:11:51.000 --> 0:11:53.760 are like, those are totally normal. I don't have hair 0:11:53.800 --> 0:11:55.360 on the back of my hands either. I've got hair 0:11:55.360 --> 0:12:00.880 in my first knuckles. Yeah, Robin Williams. Um, what's allowing 0:12:00.960 --> 0:12:03.400 us to see our hands right now and judge their 0:12:03.520 --> 0:12:07.920 size and scale is, um, what's called diffuse reflection. Which 0:12:08.280 --> 0:12:10.800 the light that's coming off of all of these light 0:12:10.800 --> 0:12:13.880 bulbs right now are hitting all these different areas, these 0:12:13.880 --> 0:12:17.000 different services on my hands, and it's bouncing off, it's 0:12:17.040 --> 0:12:22.120 being scattered right the mirror with the highly reflective surface. Um, 0:12:22.240 --> 0:12:26.240 what we have is called specular reflection. And that is 0:12:26.280 --> 0:12:30.199 where it's pretty close to the law of reflection, where 0:12:30.440 --> 0:12:33.560 the angles coming in at one or the lights coming 0:12:33.559 --> 0:12:36.840 in at one angle and coming off the at the 0:12:36.880 --> 0:12:40.959 same degree in the opposite direction. Right, Um, Which is 0:12:41.280 --> 0:12:44.160 why we're allowed to see ourselves in a piece of 0:12:44.360 --> 0:12:48.040 glass with metal on the back. And what this creates 0:12:48.080 --> 0:12:50.800 when you're looking at yourself is called the virtual image. Right. 0:12:51.120 --> 0:12:53.480 I find it fascinating. Yeah, me too, And it's a 0:12:53.480 --> 0:12:56.600 little brain melty for me, of course. But at the 0:12:56.600 --> 0:12:59.600 same time you realize, like, well, you've grown up around 0:12:59.600 --> 0:13:03.240 mirrors the whole time, and no one has any real 0:13:03.320 --> 0:13:07.160 concept of of how they work. Right, We just take 0:13:07.200 --> 0:13:10.000 for granted that they do work, but you don't really 0:13:10.080 --> 0:13:13.320 give much thought to how they're working. Right, Like the 0:13:13.400 --> 0:13:16.720 Venus effect. Did you read about that? Yeah, that that's 0:13:16.920 --> 0:13:19.720 explained that because this is where when we talk about 0:13:20.080 --> 0:13:22.920 Actually the Venus effect is two different things, and both 0:13:22.960 --> 0:13:24.920 of them kind of melt my brain. That the left 0:13:24.960 --> 0:13:28.160 and right being reversed, which is not actually true, and 0:13:28.160 --> 0:13:30.640 then the venus effects. So let's talk about both of those. Okay, Well, 0:13:30.679 --> 0:13:33.680 the Venus effect is basically just shows how little we 0:13:33.800 --> 0:13:37.280 can grasp or how little we grasp mirrors and how 0:13:37.280 --> 0:13:40.320 they work. If you look at paintings of the Venus 0:13:40.480 --> 0:13:44.960 de Milo, Venus the goddess um almost always she's holding 0:13:45.000 --> 0:13:47.560 a hand mirror, and in the painting you can see 0:13:47.600 --> 0:13:50.520 her face in the mirror, but she's looking at herself 0:13:50.520 --> 0:13:53.079 in the mirror, and her face is painted in the 0:13:53.120 --> 0:13:55.199 mirror for the benefit of the viewer. But you take 0:13:55.280 --> 0:13:58.760 for granted that she's viewing herself, when in actuality, if 0:13:58.840 --> 0:14:01.040 you could see Venus is in the mirror, she wouldn't 0:14:01.040 --> 0:14:02.760 be able to see herself she'd see you in the 0:14:02.800 --> 0:14:07.080 mirror because of the angle or the law of reflection. Yeah, 0:14:07.120 --> 0:14:09.760 and that's the only way I finally understood that was 0:14:09.800 --> 0:14:12.520 when I remembered, like in my film set Days, when 0:14:12.559 --> 0:14:16.160 you shoot a person looking in a mirror, they aren't 0:14:16.360 --> 0:14:18.800 They don't see themselves in the mirror, clearly, because you 0:14:18.800 --> 0:14:21.080 would see the camera behind them so that the mirror 0:14:21.120 --> 0:14:23.680 is angled, and it looks like they're looking at themselves 0:14:23.680 --> 0:14:25.960 and primping, but they're not seeing themselves. Pretty cool, right, 0:14:26.800 --> 0:14:29.560 So that makes sense to me now it does, isn't it. Yeah? Okay, 0:14:29.880 --> 0:14:32.840 the other thing you were saying is left and right, Yeah, 0:14:32.880 --> 0:14:35.120 it's not actually left and right. Yeah, this one was 0:14:35.160 --> 0:14:36.920 a little brain melty, but I think I finally got 0:14:36.920 --> 0:14:40.800 it too. Okay, So consider that what you're not, what 0:14:40.840 --> 0:14:44.280 you're seeing isn't actually your reflection, but another version of 0:14:44.320 --> 0:14:47.560 yourself in the mirror world. Right. If you look at 0:14:47.600 --> 0:14:49.920 it that way, then the mirror represents the halfway point. 0:14:49.960 --> 0:14:54.240 It's always halfway between you and your virtual self, right, right, 0:14:54.320 --> 0:14:57.200 Because your virtual self, that image of yourself in the 0:14:57.240 --> 0:15:01.240 mirror is always twice as it's always two times away 0:15:01.240 --> 0:15:04.320 from you. With the mirror representing the halfway point right, 0:15:04.440 --> 0:15:07.200 So your two feet from the mirror, and your virtual 0:15:07.240 --> 0:15:09.520 self is another two feet away from you. Right, You 0:15:09.520 --> 0:15:11.680 see what I'm saying. Yeah, And the left and right 0:15:11.720 --> 0:15:13.800 thing isn't really left and right, it's really front and 0:15:13.800 --> 0:15:17.400 back that are reversed. You again, think of yourself as 0:15:17.400 --> 0:15:21.080 the virtual image you walk into the mirror world, you 0:15:21.200 --> 0:15:23.440 take you go another two feet away from where you're 0:15:23.480 --> 0:15:26.000 just standing, so you're now for your four feet away 0:15:26.000 --> 0:15:28.720 from where you're just standing and turn around right, Which 0:15:28.760 --> 0:15:32.120 is weird because it actually gives the virtual image something 0:15:32.160 --> 0:15:35.360 of its own identity, doesn't it does. It's a little creepy. Yeah, 0:15:35.480 --> 0:15:37.120 So when you're looking at a mirror, you're it's not 0:15:37.160 --> 0:15:41.120 a reflection of you from the mirrors perspective. It's like that. 0:15:41.240 --> 0:15:43.320 The one example they gave was if you wrote something 0:15:43.320 --> 0:15:45.560 on a piece of paper and then held that paper 0:15:45.640 --> 0:15:47.160 up to the light and looked at it from the back, 0:15:47.240 --> 0:15:50.040 it would appear backwards. But it's not right. You're just 0:15:50.080 --> 0:15:54.600 behind it, yes, man, isn't it. Yeah? It's pretty interesting stuff. 0:15:54.680 --> 0:15:56.760 And I gotta say when you two things, when you 0:15:56.880 --> 0:16:01.880 mentioned doing mirrors, I said to myself, really, And then 0:16:01.920 --> 0:16:03.680 when we told Jerry what we were doing this on. 0:16:03.720 --> 0:16:06.560 She was like, really, yeah, but it's I think it's 0:16:06.640 --> 0:16:08.840 much more interesting than I originally thought. Well again, it's 0:16:08.880 --> 0:16:11.800 like the butterfly swings, you know, like we just have 0:16:11.840 --> 0:16:14.360 to know that if we're gonna understand absolutely everything that's 0:16:14.400 --> 0:16:17.600 going on in the world, which is our mission. Yes. Uh, 0:16:17.720 --> 0:16:20.960 should we talk about curved mirrors now? Yeah, because we 0:16:20.960 --> 0:16:23.440 were talking about virtual images, there's actually a way to 0:16:23.480 --> 0:16:27.080 project a real image where this thing isn't in the mirror. 0:16:27.080 --> 0:16:29.720 It's outside of the mirror, but it's not really there. 0:16:29.720 --> 0:16:33.760 It's a projected image and that uses, um, concave mirrors. 0:16:33.880 --> 0:16:38.040 You might be familiar with holograms, right, is that the 0:16:38.120 --> 0:16:42.000 same concept there? He uses concave mirrors. And actually, if 0:16:42.000 --> 0:16:44.160 you want to see a really cool example of a 0:16:44.200 --> 0:16:49.360 hologram produced by a set of concave and flat mirrors, um, 0:16:49.440 --> 0:16:53.400 you should type in mirrage in YouTube and look for 0:16:53.440 --> 0:16:55.720 the one that's a lowercase just mirrage And it's a 0:16:55.760 --> 0:16:59.120 little piggy um And it's pretty cool the demonstration that 0:16:59.160 --> 0:17:01.760 this guy does. Yeah, I'll check that out. But Chuck, 0:17:02.040 --> 0:17:05.240 there's concave and convex, right, yeah, convex is the one 0:17:05.280 --> 0:17:08.919 that curves outward and it reflects at a wider angle 0:17:09.400 --> 0:17:12.399 near the edges in the center, So things are actually 0:17:12.440 --> 0:17:14.760 smaller and you can cover more areas. So that's why 0:17:14.840 --> 0:17:17.199 they'll use those. Uh, they'll stick them on like your 0:17:17.200 --> 0:17:20.960 passenger mirrors, so you can see more area around your car. 0:17:21.119 --> 0:17:23.480 And it also notes you know, objects are smaller than 0:17:23.520 --> 0:17:26.520 they appear or closer than they appear. Objects are smaller 0:17:26.560 --> 0:17:29.200 than the appear. But they are smaller than they than 0:17:29.240 --> 0:17:31.680 they appear. But that's not really that doesn't matter. It's 0:17:31.680 --> 0:17:34.240 whether they're like in your back seat or not. Yeah, 0:17:34.280 --> 0:17:36.800 and they actually um, there are have been rumors over 0:17:36.840 --> 0:17:40.160 the years at department stores put convex mirrors, slightly convex 0:17:40.240 --> 0:17:42.760 mirrors in their changing rooms to make you like a 0:17:42.880 --> 0:17:44.879 pear tallerant thinner in the clothing that you try on. 0:17:45.000 --> 0:17:48.240 Remember that Seinfeld where Eline like buys that dress, figured 0:17:48.440 --> 0:17:50.640 that they had a skinny mirror, And I think Barneys 0:17:50.640 --> 0:17:53.359 are blooming deals. Yeah, forgot about that. Yeah, I don't know. 0:17:53.400 --> 0:17:56.520 I think that's probably urban legend, but who knows, um chuck. 0:17:56.600 --> 0:18:00.240 The other one, like we said, was concave convert jing. 0:18:00.600 --> 0:18:03.359 We use those for holograms. They also use that to 0:18:03.480 --> 0:18:06.080 light the Olympic torch. Yeah, I didn't realize that either. 0:18:06.160 --> 0:18:08.600 I think that's a nod to Archimedes too. Probably, so 0:18:09.440 --> 0:18:15.440 you're probably a little more um acquainted with convex mirrors. 0:18:15.840 --> 0:18:19.480 No concave mirrors for like shaving or No, those horrible 0:18:19.560 --> 0:18:23.320 mirrors that show your like hair and detail. Those are awful, 0:18:23.400 --> 0:18:27.240 they really are. Don't ever look in those nonreversing mirror, 0:18:27.240 --> 0:18:31.000 which really is pretty simple. It's just two mirrors perpendicular 0:18:31.040 --> 0:18:34.160 to each other, right, Yeah, And the deal is with 0:18:34.240 --> 0:18:38.240 that they meet at the angle and so you technically 0:18:38.280 --> 0:18:40.439 can see a non reverse image, but you've got that 0:18:40.560 --> 0:18:43.160 line running down the center of you. They don't make 0:18:43.200 --> 0:18:47.000 like a flat, single nonreversing mirror. No they don't. I 0:18:47.040 --> 0:18:49.160 think it's physically impossible. It's not like they don't make 0:18:49.160 --> 0:18:51.080 it like they're not interested. It's just can't be done. 0:18:51.119 --> 0:18:54.040 But what's funny is there's a guy named um John 0:18:54.680 --> 0:18:58.800 Derby who has a patent. In seven when he was alive, 0:18:58.840 --> 0:19:02.600 he had a patent for a nonreversing mirror. By sticking 0:19:02.600 --> 0:19:05.320 two mirrors together, I could get a patent for that. 0:19:05.359 --> 0:19:08.760 I could fill out the patent application for that you could. Yeah, 0:19:08.800 --> 0:19:11.800 it's like take mirror A and stick it perpendicular to 0:19:11.800 --> 0:19:14.280 mirror B. Right there, give me my patent. Well, but 0:19:14.320 --> 0:19:17.359 then John Derby's family would come after you. Hopefully it 0:19:17.440 --> 0:19:21.040 ran out by now. And just for simpleness, Josh, two 0:19:21.040 --> 0:19:25.280 way mirrors as seen in every cop shakedown movie ever made. Yes, now, 0:19:25.400 --> 0:19:28.560 this is fascinating, Chuck. How does the two way mirror work? Well, 0:19:28.600 --> 0:19:31.360 it's really pretty easy. It's just it's the same concept 0:19:31.359 --> 0:19:34.240 of the mirror, but it's a very thin. It's very 0:19:34.320 --> 0:19:38.359 much a lighter reflection the material they use and the 0:19:38.400 --> 0:19:41.399 coated side. When it faces the lit room, some of 0:19:41.400 --> 0:19:43.880 the light reflects and some goes into the dark room 0:19:43.880 --> 0:19:47.679 behind it. So basically like you know, you can't you 0:19:47.680 --> 0:19:50.240 can see only see one way right because of the 0:19:50.320 --> 0:19:55.360 light mainly. So it's just like very thin reflective surface 0:19:55.400 --> 0:19:58.000 where if you're not if you turn in, if you 0:19:58.040 --> 0:20:00.440 turn on lights in both rooms, you'd be we'll see 0:20:00.480 --> 0:20:03.399 through that reflective surface, right, Yeah, it's all about the lighting. Yeah, 0:20:03.560 --> 0:20:06.240 and that's a movie there. There's several movie mirror things 0:20:06.240 --> 0:20:08.600 that are done in like every movie, and that's one 0:20:08.640 --> 0:20:11.400 of them. With the cop movie and inevitably the person 0:20:11.440 --> 0:20:14.040 getting questioned will always walk right up and like be 0:20:14.160 --> 0:20:15.960 staring into the face of the person on the other 0:20:16.000 --> 0:20:18.960 side that they can't see. And then the other favorite 0:20:19.000 --> 0:20:22.919 of mine, which one of the SNL shorts aped, was 0:20:23.119 --> 0:20:26.080 um the classic horror movie scene where you where you 0:20:26.080 --> 0:20:28.320 look in the medicine cabinet and the mirror and then 0:20:28.359 --> 0:20:30.720 you open the medicine cabinet and then you close it 0:20:30.760 --> 0:20:33.160 and the dude is right behind you. That's a classic. 0:20:33.280 --> 0:20:36.320 It is there's um again on YouTube. I think there's 0:20:36.320 --> 0:20:39.760 a a montage, like a four minute montage of that 0:20:39.960 --> 0:20:43.639 being used over and times. Dude and it still gets people. Yeah, 0:20:43.760 --> 0:20:45.640 but now that the whole spin is to do that 0:20:45.680 --> 0:20:47.800 and then there's not someone there, and then they'll turn 0:20:47.840 --> 0:20:50.600 around and that's where they are something. Yeah, just jerking 0:20:50.600 --> 0:20:53.520 the audience around. That's in there too. Uh oh it 0:20:53.680 --> 0:20:56.680 is huh yeah. Yeah, it's not just people closing there 0:20:56.680 --> 0:20:59.720 someone saying there's ones where they're not standing there. Yeah. 0:21:00.040 --> 0:21:03.200 I love those movie conventions that are The other one too, 0:21:03.280 --> 0:21:05.560 is it doesn't even do with mirrors, but the scene 0:21:05.560 --> 0:21:08.119 where you're where someone is searching for the files and 0:21:08.320 --> 0:21:11.200 then the person's office after dark, and you know they're 0:21:11.240 --> 0:21:13.679 coming up the steps and they opened the door and 0:21:13.720 --> 0:21:15.680 you're like they're pinched. And then they opened the door 0:21:15.680 --> 0:21:18.239 and the person is gone, and there's like a window open, right, 0:21:18.320 --> 0:21:21.359 and it's just like the curtains. Hundreds and hundreds of 0:21:21.400 --> 0:21:23.760 time is still done yet I'm still like, oh my gosh, 0:21:23.840 --> 0:21:28.320 here they come. What about Poultergeist, the great classic mirror 0:21:28.359 --> 0:21:31.040 scene where the guys like picking at that little blister 0:21:31.200 --> 0:21:33.680 and ends up pulling his whole face off. Yeah, that's 0:21:33.720 --> 0:21:37.679 pretty creepy. Yeah, classic, Thank you Toby Hooper? Did he 0:21:37.720 --> 0:21:40.840 make that? Yeah? I like got this right? He produced it, right, 0:21:40.920 --> 0:22:07.440 that's right. I always think he directed that. What else, Chuck, Well, 0:22:07.480 --> 0:22:12.440 there's some superstitions around mirrors in folklore, um summoning Bloody 0:22:12.440 --> 0:22:14.639 Mary by saying her names three times in a mirror, 0:22:14.720 --> 0:22:19.080 or candy Man, if you're a little more recent, that's 0:22:19.080 --> 0:22:22.520