WEBVTT - TechStuff Classic: How Planetariums Work 0:00:04.400 --> 0:00:07.800 Welcome to Tech Stuff, a production from I Heart Radio. 0:00:12.039 --> 0:00:14.600 Hey there, and welcome to tech Stuff. I'm your host, 0:00:14.800 --> 0:00:17.439 job and Strickland. I'm an executive producer with iHeart Radio 0:00:17.480 --> 0:00:19.680 and a love of all things tech. It is time 0:00:20.320 --> 0:00:24.240 for a classic episode, my friends. This episode originally published 0:00:24.320 --> 0:00:29.000 on May nineteen, twenty fourteen, back when we had three 0:00:29.200 --> 0:00:33.720 pieces of tech. How far we've come. So this particular 0:00:33.720 --> 0:00:37.280 episode is about how planetariums work. So I would say 0:00:37.560 --> 0:00:41.200 it's out of this world. Let's take a listen. So 0:00:41.520 --> 0:00:44.040 there are a lot of different types of planetariums that 0:00:44.159 --> 0:00:47.199 all use a very similar approach, but you know, the 0:00:47.240 --> 0:00:50.320 actual implementation can differ between one and the other. But 0:00:50.440 --> 0:00:54.240 we wanted to talk more about all of the kind 0:00:54.280 --> 0:00:57.600 of history that built into coming up to the planetariums 0:00:57.640 --> 0:01:00.000 as well as how they actually work. Right. We didn't 0:01:00.000 --> 0:01:02.840 I just explain it's a projector and then go in 0:01:02.920 --> 0:01:06.280 from there. I mean, because because y'all basically it's a projector. Yea, 0:01:06.360 --> 0:01:08.040 So we could just say it's a projector, and if 0:01:08.080 --> 0:01:12.200 you know how a projector, it's a Friday, so we're 0:01:12.240 --> 0:01:15.000 ready to go home. But no, we wanted to actually 0:01:15.080 --> 0:01:19.160 talk about the history of planetariums because it's a fascinating story. 0:01:19.200 --> 0:01:22.959 I mean, obviously, as as a species, humans have been 0:01:22.959 --> 0:01:27.800 fascinated with the heavens since before recorded history. I mean, 0:01:27.840 --> 0:01:32.680 this is something that we've obviously been really amazed by 0:01:32.680 --> 0:01:36.960 over thousands of years. It's pretty amazing. And what's interesting 0:01:37.080 --> 0:01:40.280 is that there have been lots of different attempts to 0:01:40.640 --> 0:01:47.119 create a an indoor version of this experience, because it's 0:01:47.120 --> 0:01:49.880 not always convenient to go outside and do all your 0:01:49.960 --> 0:01:53.360 your work. And based upon thousands of years of observations, 0:01:53.680 --> 0:01:56.960 we've got pretty good at figuring out how to represent 0:01:57.040 --> 0:01:59.800 the night sky in a way that was accurate even 0:02:00.080 --> 0:02:02.920 the movement of things like planets in the moon and 0:02:03.400 --> 0:02:06.760 the sun and Earth itself. Yeah, I mean it took 0:02:06.800 --> 0:02:08.920 us a while to figure that part out, that the 0:02:08.919 --> 0:02:12.160 Earth itself was moving and not say everything else was 0:02:12.200 --> 0:02:14.880 moving around the Earth. And depending upon whom you are, 0:02:15.760 --> 0:02:19.280 you might still argue that thinking of a specific documentary 0:02:19.320 --> 0:02:24.400 that Jane Way was the voice for anyway, So assuming 0:02:24.400 --> 0:02:27.920 you're not having this geocentric view, even even that would 0:02:27.960 --> 0:02:31.280 allow you to see that the the heavens move in 0:02:31.320 --> 0:02:34.760 a very predictable way. It may take a long time 0:02:34.800 --> 0:02:37.040 for a particular cycle to happen. But once you know 0:02:37.080 --> 0:02:40.840 what those cycles are, you could predict make observations that 0:02:40.880 --> 0:02:46.160 would end up either verifying or or negating the previous 0:02:46.240 --> 0:02:51.400 guesswork and eventually make it into a science. So why 0:02:51.560 --> 0:02:57.239 our planetariums themselves awesome? Well, for one, you get to 0:02:57.240 --> 0:02:59.360 look at the stars, even if again you are in 0:02:59.360 --> 0:03:01.600 a place where you can't normally see them, like here 0:03:01.600 --> 0:03:04.639 in Atlanta, we get a lot of what's called light pollution. 0:03:05.400 --> 0:03:08.680 So that's just you know, any major city tends to 0:03:08.720 --> 0:03:10.760 have this where you've got lots of lights that are 0:03:10.800 --> 0:03:13.360 on at night, and that tends to drown out some 0:03:13.440 --> 0:03:15.560 of the stars. You can't see the fainter ones. You 0:03:15.600 --> 0:03:18.680 really only see the brightest ones that are in the sky. Uh. 0:03:18.720 --> 0:03:20.519 You know, you might be able to see things like Venus, 0:03:20.520 --> 0:03:23.720 which are that's that's extremely bright, and you might see 0:03:23.760 --> 0:03:26.919 some of the major stars and some of the major constellations, 0:03:27.240 --> 0:03:30.120 but you're missing out on a lot. Oh certainly, so 0:03:30.200 --> 0:03:32.639 unless you go way out into the middle of nowhere 0:03:32.720 --> 0:03:35.200 where there aren't so many lights, or you have to 0:03:35.280 --> 0:03:38.440 live someplace that has really strict rules about the lights 0:03:38.440 --> 0:03:40.640 at night. Because there are a few of those places 0:03:41.040 --> 0:03:43.800 you probably can't see that many and even in those 0:03:43.840 --> 0:03:47.280 places it sometimes rains or gets cloudy. That turns out 0:03:47.280 --> 0:03:51.839 clouds really inhibit the stargazing activities. Also, the sky over 0:03:51.880 --> 0:03:55.000 the Southern Hemisphere is different than that over the Northern Hemisphere. 0:03:55.080 --> 0:03:58.320 So um, if if you don't travel back and forth 0:03:58.720 --> 0:04:01.400 pretty frequently between the two, yeah, you don't know. If 0:04:01.440 --> 0:04:05.120 don't cross the line over at the equator and shout 0:04:05.120 --> 0:04:08.040 out to all my navy buddies who do. Um, if 0:04:08.080 --> 0:04:10.480 you don't do that frequently, yeah, you don't. You miss 0:04:10.480 --> 0:04:12.920 out on the way the sky looks and in the 0:04:12.920 --> 0:04:15.520 Southern Hemisphere or if you live in the Southern Hemisphere 0:04:15.600 --> 0:04:18.719 the Northern hemisphere. So to our new deal and listeners, 0:04:18.720 --> 0:04:20.360 there's a lot of you. There's actually quite a few 0:04:20.360 --> 0:04:22.880 of you. Um, I will not confuse you with the 0:04:22.880 --> 0:04:28.640 Australian listeners. We love all of you equally. So if 0:04:28.680 --> 0:04:30.320 you've never been there, but you want to see what 0:04:30.360 --> 0:04:33.760 the sky looks like, a planetarium, some of them anyway 0:04:33.800 --> 0:04:36.839 can accommodate you. A lot of them have the capability 0:04:37.279 --> 0:04:41.039 of showing the stars over any particular point on Earth 0:04:41.120 --> 0:04:44.520 like that's how sophisticated they've become so. Not only that, 0:04:44.880 --> 0:04:47.440 but they many of them can also show you what 0:04:47.520 --> 0:04:50.000 the sky would look like on any given date, So 0:04:50.080 --> 0:04:52.840 you might say, well, what did the sky look like yesterday, 0:04:52.839 --> 0:04:55.240 What will it look like tomorrow? What will it look 0:04:55.320 --> 0:04:57.800 like in a century? What will it look like a 0:04:57.920 --> 0:05:00.360 hundred centuries from now? What did it look like back 0:05:00.400 --> 0:05:03.599 in the day that Shakespeare wrote his plays? Like, you 0:05:03.640 --> 0:05:05.479 could do any of those things, and by plugging in 0:05:05.560 --> 0:05:09.280 some some numbers. The computers that handle the calculations for 0:05:09.360 --> 0:05:12.040 most of these uh devices, not all of them, some 0:05:12.080 --> 0:05:13.720 of them are a little older, but most of them 0:05:13.960 --> 0:05:17.599 can take that into consideration and actually determine what the 0:05:17.640 --> 0:05:20.680 position of the planets would be on any given date, 0:05:20.760 --> 0:05:23.680 the stars, etcetera. Which is pretty awesome. Yeah. Um. They 0:05:23.720 --> 0:05:27.000 can also be used to teach celestial navigation, and they 0:05:27.040 --> 0:05:29.520 certainly were used for that purpose during World War Two. 0:05:29.839 --> 0:05:34.920 Very useful, especially if you can't always depend upon instruments 0:05:35.000 --> 0:05:39.479 to be able to get around. Also, uh, hey, uh 0:05:39.560 --> 0:05:43.400 it teaches astronomy, which you know, I always almost left 0:05:43.400 --> 0:05:45.040 that out of the notes, and I was like, yeah, 0:05:45.080 --> 0:05:47.919 that's uh, that's a big deal. I guess that's a thing. Yeah, 0:05:48.279 --> 0:05:51.160 so obviously the astronomers out there if you want to 0:05:51.200 --> 0:05:55.880 be able to identify various star clusters things like that. 0:05:56.040 --> 0:05:59.839 And a lot of these have special um projectors that 0:06:00.080 --> 0:06:03.040 show things like the Milky Way galaxy or other nebula 0:06:03.120 --> 0:06:06.080 or things like that. And that's important. Oh sure, sure, 0:06:06.120 --> 0:06:09.320 but we will get into that later on. Um, let's 0:06:09.320 --> 0:06:12.080 talk for right now about the history of these devices, 0:06:12.120 --> 0:06:16.080 because people have been painting the sky on ceilings, I mean, 0:06:16.160 --> 0:06:19.240 for for basically ever. Yeah, I mean, like I got 0:06:19.240 --> 0:06:21.320 a cousin who has the Glow in the Dark ones 0:06:21.400 --> 0:06:25.120 that's been on her her bedroom ceiling like since she 0:06:25.240 --> 0:06:28.040 was like four. So yeah. Also, there's a star map 0:06:28.160 --> 0:06:30.440 on the ceiling of the tomb of the Egyptian official 0:06:30.760 --> 0:06:36.239 Sentement that dates from like that does predate my cousin, 0:06:36.400 --> 0:06:39.200 so a little bit. Your your argument is valid. Yeah, 0:06:39.240 --> 0:06:41.880 I mean this is something, like I said, humans have 0:06:42.000 --> 0:06:44.719 been fascinated with the stars for as long as we've 0:06:44.720 --> 0:06:48.680 been looking around and being able to express our thoughts. 0:06:48.760 --> 0:06:52.480 So it's no surprise that we're seeing evidence of that 0:06:52.640 --> 0:06:57.400 in in prehistoric and and uh, you know, just post historic, 0:06:58.160 --> 0:07:03.120 fairly historic uh you know, drawings and and uh and 0:07:03.160 --> 0:07:06.359 depictions on things like this tomb. And then we have 0:07:07.040 --> 0:07:09.680 some early examples of what could be something like a 0:07:09.720 --> 0:07:14.600 planetarium from the Arabic world. Right right there, there were 0:07:14.680 --> 0:07:17.560 Arabic tents made with holes in the fabric to let 0:07:17.760 --> 0:07:21.320 outside lights shine through, representing each star or each star 0:07:21.440 --> 0:07:24.920 as they knew them in in that time. UM described 0:07:24.960 --> 0:07:28.640 in European History Circle that twelve hundreds or so, and 0:07:28.680 --> 0:07:30.640 so that's that's you know, that's a good while back, 0:07:31.200 --> 0:07:34.400 right and then we had, uh, let's let's switch up 0:07:34.440 --> 0:07:37.520 to say, oh, I don't know, let's let's go to 0:07:37.600 --> 0:07:40.520 the idea of using globes and sky maps. This is 0:07:40.560 --> 0:07:42.880 really cool too, So starting a couple of thousand years ago, 0:07:42.920 --> 0:07:45.480 it became really popular in the West to draw sky 0:07:45.520 --> 0:07:49.120 maps on globes and um the first planetariums known to 0:07:49.200 --> 0:07:52.000 history were huge versions of these, like big enough for 0:07:52.080 --> 0:07:54.920 people to sit in. A really famous example is the 0:07:54.920 --> 0:07:58.880 gor Top globe, supposedly based on plans found among Tico 0:07:58.920 --> 0:08:02.440 Brahe's papers. Okay, so wait, wait, wait, Tico Brian, I've 0:08:02.480 --> 0:08:04.880 always heard Tycho Bray. Where did you hear Tico Brian? 0:08:05.080 --> 0:08:09.160 I'm one of my astronomy professors in college called him Tico. 0:08:09.280 --> 0:08:11.760 That's good enough for me. So, I know, I know 0:08:11.800 --> 0:08:15.760 that the Penny Arcade dude calls himself tycho, but hey, 0:08:15.960 --> 0:08:19.520 we're going with an astronomy professor's approach. I'm I'm all 0:08:19.600 --> 0:08:22.960 right with bowing to authority on this one. He had 0:08:23.000 --> 0:08:26.600 a really impressive beard. So that also, I mean, that's 0:08:26.640 --> 0:08:30.520 like credentials in the astronomy world. So that's totally cool. 0:08:31.000 --> 0:08:32.600 So that that was that was built in the mid 0:08:32.640 --> 0:08:35.280 sixteen hundreds and what's now Germany, and it was large 0:08:35.360 --> 0:08:37.800 enough for like twelve people to sit in on these 0:08:37.840 --> 0:08:41.760 circular benches that were around a table um where refreshments 0:08:41.760 --> 0:08:44.680 could be served. Obviously, yeah, um so so the so 0:08:44.760 --> 0:08:47.360 the object, this globe was about ten feet or three 0:08:47.360 --> 0:08:51.200 meters in diameter, and the stars in it were these gilded, 0:08:51.280 --> 0:08:54.960 spangled fixtures in the inside surface of the globe that 0:08:55.000 --> 0:08:57.000 we're eliminated by a lamp that would sit on the 0:08:57.000 --> 0:08:59.920 table along with your you know, snacky cakes. Interesting. So 0:09:00.160 --> 0:09:04.120 it's like it's like if you look at a regular globe, 0:09:04.440 --> 0:09:05.840 you know, that's something that we look at on the 0:09:05.880 --> 0:09:09.000 outside service obviously that's you know, representing the Earth. But 0:09:09.120 --> 0:09:11.400 this is one where we would go on the inside 0:09:11.679 --> 0:09:14.199 and we're looking at the inner wall, which is representing 0:09:14.240 --> 0:09:17.440 the heavens, the heavens right right, and the outside of 0:09:17.440 --> 0:09:20.559 it was actually painted like like the Earth. It had 0:09:20.559 --> 0:09:22.400 all of the continents and everything on it. Pretty cool 0:09:22.520 --> 0:09:25.520 that whole globe shell could could rotate around the viewers 0:09:25.559 --> 0:09:28.080 thanks to some water powered machinery. And it took some 0:09:28.240 --> 0:09:32.920 ten years to build and weighs like three tons, despite 0:09:32.920 --> 0:09:35.200 which it was moved to St. Petersburg as a gift 0:09:35.280 --> 0:09:39.520 to Peter the Great in seventeen seventeen. Shortly after that 0:09:39.679 --> 0:09:44.240 it was partially destroyed in a fire, then restored, then 0:09:44.320 --> 0:09:47.199 stolen by the Germans in World War Two, found by 0:09:47.280 --> 0:09:52.240 US troops, and restored again to St. Petersburg. Pretty sure, 0:09:52.280 --> 0:09:55.400 that should be an Indiana Jones plot, right, it's great, 0:09:55.400 --> 0:09:59.880 And this thing weighs three tons. It takes some determination 0:10:00.200 --> 0:10:03.839 to steal anything that weighs three tons. That's pretty incredible. 0:10:04.120 --> 0:10:08.000 But so the practice of making these these enterable sky 0:10:08.080 --> 0:10:11.360 globes like this unwieldy as they were persisted into the 0:10:11.440 --> 0:10:14.880 nineteen hundreds, and the Museum of the Chicago Academy of 0:10:14.920 --> 0:10:18.880 Sciences built their atwood globe as late as nineteen um 0:10:19.080 --> 0:10:21.199 and that's that's about the same size a little bigger 0:10:21.200 --> 0:10:23.800 at measure sixteen feet that's about five meters in diameter 0:10:24.280 --> 0:10:28.080 um and shows six stars plus the planets in our 0:10:28.120 --> 0:10:32.200 Solar system as as holes through which outside light can shine. 0:10:32.240 --> 0:10:36.200 It's electric and the shell can spin once every eight 0:10:36.240 --> 0:10:39.400 minutes around viewers. Interesting, and so this is kind of 0:10:39.520 --> 0:10:42.079 it's it's like it's taking a note back from those 0:10:42.120 --> 0:10:45.880 old Arabic tents, right, the lights coming from outside shining 0:10:45.880 --> 0:10:48.520 through holes, and that's what represents the stars, very much 0:10:48.559 --> 0:10:50.679 like those tents that had the holes pin break through 0:10:50.679 --> 0:10:53.720 the tent canvas right right. You know, of course this 0:10:53.840 --> 0:10:57.559 depends on either in this case probably electric lights outside 0:10:57.640 --> 0:10:59.320 or in the case of those tents, having a good 0:10:59.360 --> 0:11:02.960 source of sun light in order to see what's going on. Um. 0:11:03.120 --> 0:11:05.920 By the way, a couple of distinctions that I wanted 0:11:05.960 --> 0:11:08.040 to make here. If you've ever heard of an order 0:11:08.160 --> 0:11:11.120 e um, that's that's a physical model of the planets 0:11:11.120 --> 0:11:15.880 in our Solar system and sometimes also called a planetarium, 0:11:15.920 --> 0:11:20.160 and they're also sometimes included in planetariums. So that's nice 0:11:20.160 --> 0:11:23.560 and confusing, right, So orris are if you've ever seen 0:11:23.600 --> 0:11:25.640 one of those physical models where you've got the Sun 0:11:25.679 --> 0:11:27.160 in the center, and then you have all the different 0:11:27.160 --> 0:11:30.160 planets that can spin around the Sun. Sometimes they are 0:11:30.240 --> 0:11:34.160 actually mounted on gears or motors so that it represents 0:11:34.200 --> 0:11:37.959 the accurate movement of each of these bodies as they 0:11:37.960 --> 0:11:41.200 would move in relation to one another. So for example, 0:11:41.240 --> 0:11:44.160 the Earth's uh, the Earth's movement around the Sun is 0:11:44.160 --> 0:11:48.559 different from Saint Mars, which is different from Neptune or Saturn. Anyway, 0:11:48.679 --> 0:11:50.959 you would be able to watch these and see how 0:11:51.000 --> 0:11:53.520 they move in relation to each other, see the times 0:11:53.559 --> 0:11:56.280 when they happen to align, when they get out of alignment, 0:11:56.840 --> 0:12:00.559 and it's really fascinating to see an or but it's 0:12:00.600 --> 0:12:03.960 from an outside perspective. You're not looking from the inside out. 0:12:03.960 --> 0:12:06.679 You're looking as if you were able to distance yourself 0:12:06.760 --> 0:12:08.640 all the way out of the Solar system and look 0:12:08.720 --> 0:12:12.280 in on it, right and and being that especially early ones, 0:12:12.360 --> 0:12:14.199 where we're you know, the planets were all on their 0:12:14.200 --> 0:12:16.440 little rods and would all be going on a on 0:12:16.480 --> 0:12:19.400 a single plane around the Sun, rather than in the 0:12:19.440 --> 0:12:22.080 truth three dimensions in which right right, it would be 0:12:22.160 --> 0:12:24.640 it would be as if we had a completely flat 0:12:24.679 --> 0:12:27.200 solar system, which is not exactly true. Yeah, it's like 0:12:27.200 --> 0:12:29.480 Star Trek world. Everything just comes right knows up to 0:12:29.520 --> 0:12:31.559 each other. Yeah. And also they would move in and 0:12:31.800 --> 0:12:34.479 essentially perfect circles. They wouldn't have these kind of elliptical 0:12:34.600 --> 0:12:37.480 orbitals because that's really hard to do with physical rods. 0:12:38.040 --> 0:12:40.679 But you know, my favorite or y of all time 0:12:41.120 --> 0:12:43.200 is from the movie The Dark Crystal, and it's what 0:12:43.280 --> 0:12:45.679 Augra had. Now that of course was an or y 0:12:45.880 --> 0:12:50.040 for a fictional solar system, but was amazing that an 0:12:50.160 --> 0:12:53.400 enormous things spinning around all over the place. That that 0:12:53.480 --> 0:12:56.480 lady still creeps me out as an incredible movie that 0:12:56.559 --> 0:12:59.679 everyone should go see. Uh oh, absolutely, yes, very much so. 0:13:00.040 --> 0:13:06.720 Plexis I can't okay science besides planetariums and uh and 0:13:06.840 --> 0:13:09.160 or planetaria if we want to talk about or reason 0:13:09.160 --> 0:13:14.000 in that sense, and these globes, we also have the 0:13:14.040 --> 0:13:18.520 concept of keeping track of astronomical phenomena in other ways 0:13:18.600 --> 0:13:21.840 that aren't again all immersive. All right, Well, part of 0:13:21.880 --> 0:13:27.080 the function of a planetarium is as an astronomical clock, right, 0:13:27.520 --> 0:13:29.520 like you were saying earlier, being able to to go 0:13:29.559 --> 0:13:31.280 into the future, into the past and see what the 0:13:31.320 --> 0:13:33.840 stars looked like at any given point. Um, and you 0:13:33.920 --> 0:13:39.079 and Joe talked about a really famous one Antiquathera device 0:13:39.160 --> 0:13:42.600 or Antiquithera mechanism, which is a some people would call 0:13:42.760 --> 0:13:46.920 the oldest computer and analog computer. And yeah, on Forward 0:13:46.920 --> 0:13:49.280 Thinking we did a podcast. No I think I think 0:13:49.280 --> 0:13:51.320 you did it on tech Stuff. It was well days, 0:13:52.280 --> 0:13:55.080 that's right, that's right. See here's the things that I do. 0:13:55.160 --> 0:13:57.679 Too many shows for too many different different versions. Yes, 0:13:57.720 --> 0:13:59.760 we did do the tech Stuff one so as a 0:13:59.800 --> 0:14:03.240 re minder, because obviously I need one. Uh. The Anticathera 0:14:03.360 --> 0:14:07.520 device was this, uh, this gadget that had been lost 0:14:07.640 --> 0:14:12.040 in a shipwreck and recovered by sponge divers, and it 0:14:12.120 --> 0:14:14.000 was recovered in very poor repair. It was all these 0:14:14.000 --> 0:14:16.760 different pieces and some of them were big chunks and 0:14:16.800 --> 0:14:20.560 some were smaller pieces. Uh. And eventually it took decades 0:14:20.600 --> 0:14:22.640 to do this, but eventually we figured out that this 0:14:22.680 --> 0:14:27.160 was an astronomical computer. It was able to show where 0:14:27.600 --> 0:14:29.800 the position of the planets were in relation to the 0:14:29.800 --> 0:14:33.920 Earth on any given date, including the position and phase 0:14:33.960 --> 0:14:36.360 of the Moon and the position of the Sun. And 0:14:36.400 --> 0:14:40.560 you would turn a crank in order to adjust the 0:14:40.600 --> 0:14:43.320 dials so that you could change it to any date 0:14:43.440 --> 0:14:47.320 and see what what the that actual alignment happened to 0:14:47.360 --> 0:14:49.400 be on that given date. It was also very useful 0:14:49.440 --> 0:14:53.240 for things like planning out specific events, because you could 0:14:53.560 --> 0:14:55.400 do this and find out when there was going to 0:14:55.440 --> 0:14:58.640 be an eclipse, for example, and an eclipse tended to 0:14:58.680 --> 0:15:02.480 be considered a bad men, so you might think, hey, 0:15:02.520 --> 0:15:05.000 this big festival, we want to have what happened to 0:15:05.040 --> 0:15:06.880 fall on in the eclipse, So we're going to have 0:15:07.120 --> 0:15:11.120 a special a special festival that's going to be three 0:15:11.120 --> 0:15:13.560 weeks earlier so that we don't have to worry about that, 0:15:13.920 --> 0:15:16.600 or an Olympics event that there would be another example, 0:15:16.720 --> 0:15:20.680 So it's really super cool. However, again this was something 0:15:20.720 --> 0:15:24.800 that was relatively small. We're talking about like the size 0:15:24.800 --> 0:15:27.840 of a large book, and so you're looking at at 0:15:27.880 --> 0:15:30.840 these dials rather than again being immersed in the experience. 0:15:31.080 --> 0:15:33.600 But it was really useful for checking out, you know, 0:15:33.680 --> 0:15:36.400 what a a a planetary alignment would be on any 0:15:36.440 --> 0:15:40.440 given date, because again they understood that the movements of 0:15:40.440 --> 0:15:44.120 the planets were regular and cyclical. Yeah, and so they 0:15:44.120 --> 0:15:46.680 were able to do this, and I don't want to 0:15:47.560 --> 0:15:50.960 minimize how difficult this was. They had to build exact 0:15:51.560 --> 0:15:55.360 gear ratios to represent the movement of all these planets 0:15:55.400 --> 0:16:00.200 and sometimes hand machining those yeah, yeah, yeah, and dorble 0:16:00.200 --> 0:16:02.360 amount of precision is required and sometimes you know, you 0:16:02.360 --> 0:16:04.400 would have to have things move backwards a little bit 0:16:04.680 --> 0:16:07.720 and then move forwards because from our perspective, that's the 0:16:07.760 --> 0:16:11.440 way things seem to be moving. So really really complicated stuff. 0:16:11.840 --> 0:16:15.960 Uh but still again, that's that's not quite an astronomical clock. 0:16:16.040 --> 0:16:19.240 It's very similar to one. Once we looked at actual 0:16:19.360 --> 0:16:23.200 astronomical clocks. Those look like clocks, but they happen to 0:16:23.240 --> 0:16:27.360 have either a dial or sometimes it's a uh, you know, 0:16:27.640 --> 0:16:31.600 a little physical representation of what the planetary alignments are 0:16:31.600 --> 0:16:33.880 going to be or those phase of the moon or whatever. 0:16:34.160 --> 0:16:37.160 These have been popular since the Middle Ages. There were 0:16:37.200 --> 0:16:40.080 also some of those posh sky globes that could hypothetically 0:16:40.160 --> 0:16:42.920 predict the movement of celestial bodies, and Archimedes is said 0:16:42.920 --> 0:16:48.440 to have had one background two right, so uh, probably 0:16:48.440 --> 0:16:52.280 true lost stuff about that time period. Difficult for us 0:16:52.320 --> 0:16:55.880 to verify, but but I'm willing to believe it because 0:16:56.040 --> 0:17:00.200 they are wicked smart. So uh yeah, yeah, again, we're 0:17:00.200 --> 0:17:02.160 still talking about stuff that lets you look at it. 0:17:02.160 --> 0:17:06.119 It doesn't surround you like the crazy um the globes 0:17:06.160 --> 0:17:08.480 where you would walk inside and take a seat. But 0:17:08.600 --> 0:17:13.520 that's what leads us to the more modern day planetarium 0:17:13.560 --> 0:17:17.840 that would require projection and not not like standing in 0:17:17.880 --> 0:17:20.880 the middle and projecting out by speaking more loudly. We're 0:17:20.920 --> 0:17:25.959 talking about light projection here. Okay, we've got some some 0:17:26.000 --> 0:17:29.280 planetarium talk ahead of us, but uh says here on 0:17:29.400 --> 0:17:31.399 my clock that it's time for us to take a 0:17:31.480 --> 0:17:44.440 quick break and we'll be right back. Okay, So projectors planetarium, 0:17:44.480 --> 0:17:47.960 all right. The first one was installed in a roof 0:17:48.040 --> 0:17:51.639 on a rooftop in Jenna, Germany. And I apologize, I 0:17:51.680 --> 0:17:54.639 suppose it would it be Jenna, Germany? The j is 0:17:54.720 --> 0:17:58.480 generally pronounced like a y. I did well, Jacob would 0:17:58.520 --> 0:18:03.240 be a cub Johan. I, I see where you're going, 0:18:03.320 --> 0:18:06.719 and I approve. I'm guessing it's Jenna. Any of our 0:18:06.760 --> 0:18:10.080 German listeners who would like to to reprimand me on 0:18:10.080 --> 0:18:13.720 my pronunciation feel free, because um, I should know better 0:18:13.800 --> 0:18:16.480 at this point. But it was an optical projector, so 0:18:16.600 --> 0:18:19.560 it actually used light and lenses to project images of 0:18:19.640 --> 0:18:23.960 stars on a curved surface the inside of a dome. Yeah, 0:18:24.359 --> 0:18:27.959 so this dates all the way back to nineteen thirteen 0:18:28.040 --> 0:18:30.679 for the earliest of the plans. That's when a man 0:18:30.760 --> 0:18:34.480 named Oscar von Miller commissioned the device for the Deutschet 0:18:34.520 --> 0:18:38.679 Museum in Mind. So the idea to actually use projection 0:18:39.400 --> 0:18:42.399 was agreed upon in nineteen fourteen. There was this big 0:18:42.440 --> 0:18:46.919 meeting and generally speaking, most people credit and engineer by 0:18:46.920 --> 0:18:50.640 the name of Walter Bausfeld who came up with this 0:18:50.720 --> 0:18:54.040 idea to use a projector. He was working with the company, 0:18:54.119 --> 0:18:57.080 a company called Carl Zeiss, which was an optics company 0:18:57.200 --> 0:19:00.240 still is in fact, is that that's very true? Uh, 0:19:00.280 --> 0:19:03.720 And they decided that they would use this kind of approach. 0:19:03.880 --> 0:19:05.960 They decided that they wanted to use something that was 0:19:06.400 --> 0:19:09.640 fairly new, the idea of a new source of light 0:19:09.840 --> 0:19:12.280 for people at that time. Well, their their original idea 0:19:12.320 --> 0:19:16.520 here was was to use those fancy newfangled light bulbs 0:19:17.200 --> 0:19:20.159 as instead of a pin prick, instead of having a 0:19:20.160 --> 0:19:22.480 pin hole for for each light source, they wanted to 0:19:22.560 --> 0:19:25.240 use a light bulb for each star. And they very 0:19:25.320 --> 0:19:29.920 quickly realized how complex and expensive and terrifying that would be, 0:19:30.040 --> 0:19:32.720 especially if you want to be able to move your 0:19:32.760 --> 0:19:35.120 field of vision right right. So if you had all 0:19:35.160 --> 0:19:37.840 these stars in fixed positions on the dome. How do 0:19:37.880 --> 0:19:40.000 you move them if you want to if you want 0:19:40.000 --> 0:19:42.360 to move the entire ceiling and that's oh, that's not good. 0:19:42.400 --> 0:19:45.199 Can you imagine the heat generated from those old bulbs 0:19:45.200 --> 0:19:47.880 to all of those things. So this this one engineer, 0:19:47.960 --> 0:19:52.200 Vaulter Uh supposedly said, hey, why don't we put the 0:19:52.280 --> 0:19:54.760 light in the middle and then shine it out on 0:19:54.800 --> 0:19:57.680 the on the on the inside, as opposed to poking 0:19:57.680 --> 0:19:59.800 holes on the inside and putting these light bulbs through. 0:20:00.359 --> 0:20:04.600 And people said, you're crazy, except for another engineer, and 0:20:04.680 --> 0:20:07.359 this one. This is a very interesting and tragic story. 0:20:07.400 --> 0:20:09.600 There's actually a really good documentary that we'll talk about. 0:20:09.640 --> 0:20:13.120 But there's an engineer, a scientist, an engineer named Rudolph 0:20:13.200 --> 0:20:17.560 Straubel who expanded upon Bauersfeld's suggestion. He actually said, wait, 0:20:17.600 --> 0:20:19.560 this is a great idea. We can use a projector, 0:20:19.840 --> 0:20:22.520 and not only can the projector show things like the 0:20:22.520 --> 0:20:25.120 the position of planets, which was that that was kind 0:20:25.119 --> 0:20:27.320 of the initial approach was, well, we can show the 0:20:27.320 --> 0:20:29.480 planets this way, So no, we can actually show the 0:20:29.520 --> 0:20:32.320 stars this way too. We don't have to just rely 0:20:32.400 --> 0:20:34.240 on this as being a way of showing the planets, 0:20:34.680 --> 0:20:37.480 and they all began to work on this. Now, Strawble 0:20:37.480 --> 0:20:42.159 would eventually leave the museum and this his position working 0:20:42.200 --> 0:20:46.359 on this project because he refused to divorce his Jewish wife. 0:20:46.960 --> 0:20:50.200 So this was the rise of the Nazis in Germany 0:20:50.200 --> 0:20:54.320 at the time. And UM there's a documentary called Planetarium 0:20:54.359 --> 0:20:58.800 that really follows this, and the the general perspective on 0:20:58.840 --> 0:21:03.840 Planetarium is that straw was actually a major contributor to UH, 0:21:03.960 --> 0:21:07.000 to this first planetarium, but his work was all but 0:21:07.160 --> 0:21:11.000 erased by the Nazis, and then the Nazis attempts to 0:21:11.000 --> 0:21:16.080 erase it were then subsequently erased, partly because the the company, 0:21:16.320 --> 0:21:19.600 the Zeiss Company, got split into two companies after World 0:21:19.640 --> 0:21:21.720 War Two. Half of it was in the East Germany, 0:21:21.800 --> 0:21:24.639 the other half in West Germany, and too for the 0:21:24.680 --> 0:21:28.600 West Germany side to UH to talk about Strawble would 0:21:28.640 --> 0:21:31.399 have also been to admit that they had bowed to 0:21:31.560 --> 0:21:37.760 the Nazis UH demands, and so it was not politically UH, 0:21:38.280 --> 0:21:41.600 let's see, what's the rightway prudent. It was not prudent 0:21:41.840 --> 0:21:45.120 at that at that juncture, so to speak, to make 0:21:45.119 --> 0:21:47.880 that admission. So if you're really interested to hear more 0:21:47.920 --> 0:21:51.000 about the uh, the drama behind that and also the 0:21:51.720 --> 0:21:55.480 truly the tragedy behind that story. Check out the documentary 0:21:55.480 --> 0:21:58.879 Planetarium at Anyway, getting back to the planetarium itself, it 0:21:58.960 --> 0:22:03.080 took year of research and development before construction could begin, right. 0:22:03.160 --> 0:22:07.080 Also they were there was a war from from uh, yeah, 0:22:07.119 --> 0:22:09.199 there was World War one, yeah, and then and then 0:22:09.240 --> 0:22:13.159 the nineteen fourteen nine eighteen yeah, so that we had 0:22:13.200 --> 0:22:16.440 World War one going, so that that puts things on hold. 0:22:16.640 --> 0:22:20.040 Construction will begin in nineteen nineteen. It wouldn't be completed 0:22:20.080 --> 0:22:23.720 until nineteen twenty three and was first shown on a 0:22:23.840 --> 0:22:27.960 rooftop in Jena, Germany, and then would eventually move to 0:22:28.080 --> 0:22:32.000 its permanent home in the Deutsche Museum in nine and 0:22:32.280 --> 0:22:36.520