Keeping Time

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0:15Hey and welcome to the podcast I'm Josh and there's Chuck and Jerry's here too And we're just hanging out And we decided hey Let's do some talking about timekeeping So that's what we're doing today Yeah, Olivia helped us put this one together I think the charge was, hey, how about something on the history of timekeeping without getting too in the weeds about how all of these things work? Because that's a whole other thing, like if you want to really break down clocks and watches. But I think she did it just right. The Goldilocks zone, as they say. Oh, nice. Nice astronomical, cosmological reference there.

0:54Well, I think that is a reference for a lot of things, right? Nope, just that. Okay. Where'd you get this idea? Because this was when you came up with. You know, man, I don't know. I think I was maybe thinking about a watch on my wrist. Okay. And then wondering, or no, maybe I saw someone had a, what do you call those things? An hourglass. Okay. And I was wondering about just hourglasses. And then I started thinking about like just, you know, the concept of time and when people started keeping time. and I was kind of had a hunch that I was right that, you know, the need to keep time didn't come around until much later.

1:34So like, as we'll see, early timekeeping was more like seasonal or astrological. And it didn't get to be a thing like, hey, I have an appointment at a certain minute until much, much later. Yeah, but earlier than you'd think or earlier than I thought, at least. Yeah, agreed. So speaking of timekeeping, you really can kind of say the whole thing just started out with the sun. And one of the neat things about life on Earth is that you can cast a shadow. Most things cast a shadow, with the exception of maybe like a me-bay or something like that. But if you put like a stick in the ground, it's going to cast shadows that move throughout the day.

2:16And if you really pay attention to this kind of stuff, you can actually use it to track time throughout the day. and that is almost certainly the earliest way that humans track time. And the stick they put in the ground is widely known as a gnomon, G-N-O-M-O-N. I think it means rod in Greek, maybe. I also saw that it was slang in Greek for penis. Oh, really? Yeah. And that just— Like, hey, check out the gnomon on that guy? Yeah, almost exactly that, if not that. But just said in ancient Greek. Okay, gotcha. In Hellenic. Yeah. But just tracking the shadow that the Noman cast, hopefully just a stick in the ground.

3:01Yeah. That was early timekeeping. Oh, man. I have a thousand jokes. I'm just going to walk right past at this point. Good for you, buddy. You're a pro. I know. I'm growing up here at 54. So that was, yeah, that's what people use for the longest time. and that eventually, as we'll see, would carry over to things like sundials. But it's no surprise that China was way ahead of the game as far as timekeeping goes because the oldest surviving sort of actual thing that we have comes from northern China from an archaeological site that they found dated back to 2300 BC. And again, as you'll see, this is a recurring theme, like I mentioned.

3:42It wasn't necessarily like, hey, we got to keep the time from day to day. it's more like let's calculate the seasons or, you know, the things happening up in the sky. Right. Because it was snowing in the middle of China and somebody said, what season is it? And somebody else said, let's find out with this gnome on. And the other person's like, no, no, pull that out. And they're like, no, I mean the stick. Right. They said you can get canceled for that. So if you're like, well, that sounds a lot like a sundial. You're right. The thing that sticks up for the sundial is a nomon. There's another version of it that's even earlier than the sundial, it seems, from ancient Egypt called the shadow clock.

4:23Yeah. It's actually really hard to describe. It's much easier to just go look up, but imagine a capital T laying flat on its back on the ground, and it's raised its head and neck up to look at its feet. That's essentially... That's kind of perfect, actually. Thank you. I really thought about that one for a while, I have to admit. But the shadow that that crossbar, the top of the T casts on the rest of the T over the day is demarcated. So you can track six hours a day as the sun is rising in the east, and then you turn it around at noon, and then you track the next six hours as the sun is setting in the west.

5:00Pretty spectacular considering that's close to 3 ,000 years old. Yeah, for sure. For that descriptor, did it help you that you were laying flat on your back with your neck raised up looking at your feet? Sadly, I have to admit that I had to go lay down and figure it out myself. Okay, that's good. But yes, I was. Yeah. Nice work. Finally, to the sundial, the first round sundial that we kind of know as a sundial. Seems like it was created by a Greek philosopher named Anaximander. Very cool name. Not Alexander, but Anaximander of Miletus. This was 6th century B.C. But again, probably still tracking seasons at this point.

5:46The first sundials out of Greece that actually marked hours, like when people started keeping track of the hourly time. And as we'll see, it, you know, it just gets more specific until we eventually, much later, we'll get to minutes. But the hourly timekeeping started in 350 BCE. Yeah. And then very quickly after that, around 280 BCE, they came up with the hemicycle, which is imagine like a cube block of stone with a basin, a bowl carved out of the middle. And then they managed to cut it perfectly in half so that you just have half of a bowl. That's a hemicycle because it turns out all you need is half a bowl to make a sundial like that.

6:25And I really do wonder if somebody built them like that. Like they'd make the one, split it in two, and then all of a sudden they had two hemicycles to sell. I bet. You're getting really good at describing things at this juncture in your career. It took me long enough. We're almost to year 18. It is, it's dismaying to try to explain something and just make it even more confusing than it was initially. I finally got dismayed enough that I decided to do something about it. And what I did was lay down naked and think it over. By the way, quick correction, because a listener just wrote in about this.

7:01We're about to be at year 19 and completed year 18, technically. No, really? Yeah, because year 19 and year 20 are the two next years. Does that make sense? It does, but I feel like it's wrong because started in April 2008 and going to April of 2026, that's 18 years. completed. I see. Yeah, I should have known right when somebody busted out math, I should have been like, yeah, that's right. The cool thing about the the hemicycle, besides the fact that people back then probably said, is that thing a hemi when they walked by? You know, I couldn't resist that one. But they knew at that point, it's a pretty smart thing that the sun's position changes over the course of the year, over the course of those seasons, obviously shorter winter hours, which we're going to get to.

7:55But they accounted for that. They had sundials that would show the time using multiple arcs carved into the hemisphere to account for that sun changing over the course of the year. Yeah, so like the lines of the hours went up like longitude and then the seasons were like latitude. And I guess just depending on how high up or how shallow the shadows were, you could tell what season it was because it was within one of those arcs or two of those arcs or three or four, right? Yeah. Yeah. And, you know, I mentioned the seasonal hours when Greek sundials started dividing daytime into 12 equal parts.

8:31Obviously not hours because we eventually ended up at 24, like not hours as we know it, but they would depend on the length of the season. So it's not like they accounted for it. So they were all uniform. It was just like, hey, sometimes during the year what they will one day call an hour is longer than others, which would lead to some kind of a cool thing where ancient texts in Greece would refer to that like a winter hour or something that could be done in a shorter amount of time. Like that'll just take you a winter hour. Yeah. And this was so this is the ancient Greeks. This lasted well into the medieval period.

9:03That's how people did hours. The hour was longer in the summer. The hour was shorter in the winter. And it was essentially their way of what we do for daylight savings time by adjusting. Yeah, except we're just, you know, modern humans are way too anal to just let it kind of flow like that. Still got to be exact, you know? Right, right. Okay, so you got the sundial, and everybody was like, well, we move around a lot, and not every place has a sundial, but I always want to know what time it is. And what humans do is take a technology and figure out how to shrink it down into a portable size, and they did that with sundials too, usually made of bronze.

9:44and because they were mobile, they would also have settings and often instructions on how to adjust it depending on where you were in the world. Like some of the ancient ones that have been found have like, just put it to this setting if you're in Constantinople or put it in this setting if you're in Luxor, right? And then other ones, you kind of have to figure it out a little more based on latitude, but they were portable and essentially they were like pocket watches, but amazing bronze spheres sometimes. Yeah, so like once they could do that, they would hang it facing the sun so that that little pointer's, I guess it was still called a nomon at this point?

10:26I would think so. I think some people still call them nomons when they're referring to sundials. Yeah, I think you're right. But they would face the sun so that that pointer's shadow would hit the correct hour. Later on, they had different types that had like a pinhole that let the beam of sunlight come through and actually shine a mark on the hour, which was like super advanced at the time. Yeah, it was like the Staff of Ra model. Oh, yeah. So there was a big reason that people were keeping track of the hours in ancient Rome, especially by the time Rome came around. It wasn't necessarily to keep appointments, although they certainly had that kind of thing, or to keep time on stuff.

11:04One of the big things over the years in different cultures, it turns out, was they needed to time things, especially for something like drawing water. Like water was a communal resource and everyone had a certain allotment and they would divvy up those allotments, not by measuring how much water was taken out, but by taking as much water as you can within this, you know, before this beam of sunlight reaches this little line, essentially, right? Yeah, yeah. But in Rome, they had an extra reason for it. And that was because the hours of every single day or the first 12 hours of every single day, because it wasn't initially that they were also like, let's track the nighttime, too.

11:45They just tracked from sunrise to sunset, typically. Each of those hours was associated with the different astrological sign. It was called planetary hours. And it was because so you could maximize whoever you are worshiping. So like if you were worshiping Selene, the moon goddess, you wanted to do that three hours after sunrise on Monday. And so you would use some sort of timekeeping device to keep track of that. Yeah. And the same, of course, is true in Islam. Once that became a big thing, the Muslims adopted sundials because they're, you know, have to pray in different increments at different times.

12:23So it was really to kind of keep up with their prayer hours. And they are the ones who came up with, like, if you have a sundial in your garden, it's a little thing, which we have one of those. I bought one for Emily a few years ago. Cute. That kind of sundial is what the Muslims came up with. The one that's got the flat circular base and that Noman is, am I saying that right? Yeah. The Noman is parallel to the polar axis of the planet Earth. Yeah, they also laid trigonometry on the whole thing and came up with a bunch of different kinds of sundials. There's one that was conical. And remember the hemicycle?

12:59Imagine taking that and just kind of squishing the bowl and adjusting it at an angle. That's what a conical sundial is. They look amazingly cool. So I say look one of those up. and then finally I think before we break we should give a shout out to early 13th century Moroccan mathematician Abu Al-Hazan Al-Marakushi because this is the dude that was finally like you know what uniform hours is where it's at and we should start kind of keeping track of this stuff in a uniform way like actual real timekeeping and that kind of spread out all over the world from there Very nice. Yeah. All right. Well, let's take that break then.

13:42It's time. All right. We'll be right back. Learn some stuff with Joshua and Charles. Yeah, Gary, too. Stuff you should know.

14:05Okay, Chuck. So we're back. And before we move on, I want to say that I finally got it. Reggie Watts. A Reggie Watts. Ha ha! Did you listen to it in QA? Yeah, when I was QAing it, I got it. And I was like, man, that zoomed right past me. Well, you were in a thought, and I slipped it in there very stealthily. It was very great. All right, nice little treat for you. We're talking about the National Radio Quiet Zone episode, by the way, everybody. That's right. So, you got sundials. Next thing that we moved on to is water. That's right. A bunch of different cultures came up with water clocks. It's not clear if, again, it started in China and moved to Greece and then moved to the Muslim countries.

14:44Who knows? But it's also possible that people came up with this. There were just so many things available to you to use to try to keep track of time. And there were really simple water clocks. Water was eventually used to run mechanical clocks. But the first ones essentially were like almost hourglasses made of water. Yeah. I mean, essentially what you're doing is you're either keeping track of time by water draining out of something that's marked by increments or filling something up that's marked by increments, right? Yeah, pretty much. I mean, that's essentially it. And you could supplement sundials with these because on a sundial, if it was really overcast, you had no idea what time it was.

15:29At night, these things worked as well. Really, there were two problems with them. One was that they would freeze if it was freezing. Your water clock probably wouldn't work quite as well. And then also the viscosity of water can change depending on variables like temperature and stuff like that. So they weren't entirely accurate or reliable all the time. But they did the trick for enough time that people started to improve on them and add different kind of engineering principles like floats and valves and siphons to regulate water more accurately. Yeah. I wonder if there was ever like, sorry, I'm late.

16:12You know, we had a cold snap, my water clock froze. Like, you got to move those things inside, buddy. I guarantee somebody used that excuse. Yeah, for sure. But because of the issues with water and temperature and stuff like that, mercury became a pretty reliable substitute. This was in 10th century CE, and it was a Chinese engineer who figured this out. And that basically, you know, solved a lot of the problems because mercury wouldn't freeze. It wouldn't have different viscosities at different temperatures, and it would ensure that you're on time to that appointment. Yeah, and that engineer was Zhang Zijun.

16:48Yeah, show off. I was just going to walk right past that. Here's my favorite kind of early time. Ooh, me too. Is it? Yeah, I'm not surprised. Yeah. Incense clocks. Yeah, and I'm not even into incense anymore. I was in college, I think, like most people are. Same here. I used to burn some frankincense, man. Yeah, me too. But I really love this one. This existed in China at least since the 6th century CE. Also in other parts of Asia and Korea and Japan, for sure. But I love the idea because essentially it's almost like a fuse. And as we'll see, it sometimes was a literal fuse. But incense was burned and used as a timer.

17:27Or like how quickly does that thing burn down and stop burning? Yeah. The coolest ones, though, were incense clocks that were like a box. And it was essentially like an intricate maze that you would pack with incense and then light it. And there were different, I guess, stencils that you put on top of the box to create different times. So like if you wanted an hour, that was a very simple maze. if you wanted the whole night, it was a much more intricate maze. And that's another thing I would say to look up. There's a lot of stuff you should go and look up throughout this episode, and incense clocks are definitely one of them.

18:06Yeah, but I'm glad you saved this one for me because I think it's the coolest part about all of the incense clock stuff is that they had different scents, and it just makes sense, over the course of a night where you could smell the time. So you knew when a certain smell came up what time it was, which I think is super like ingenious in its simplicity and also like, you know, you know what happens at Sandalwood time. The sexiest time. Yeah, I've got jokes that I'm keeping to myself. Yeah, good. There are also alarm clocks. You could use the heat from an incense stick, I guess, or whatever to basically burn through a thread and drop a bunch of like bells or something into a metal dish.

18:50That'll wake you up for sure every time. And apparently Chinese messengers would take incense and light one end and put the other in between their toes and wake themselves up like that, which is, man, just drink a bunch of water. That's all you need to do. Don't burn your toes. Yeah, that's true. But like I said, that's like literally lighting a fuse and it like, you know, you get the hot foot and, you know, it's time to get up and deliver the mail or whatever. That's right. We also have candle clocks that came along. This is the medieval era, notably Alfred the Great supposedly would get his day together and time it by six candles.

19:28Each would burn for about four hours. So six times four, 24. Yeah, you could also take, say, a four hour candle and break it like just mark equal lines across it and basically keep track of time like that, too. Then there's astrolabes. I'm not even going to try to really describe an astrolabe. Go look those up. They are incredibly intricate mechanically. They were invented by Muslims in, I think, the 6th century CE. So it's just amazing that they were able to do this. And astrolabes were used at sea until the sexton came along about a thousand years later, essentially. That's how effective they were.

20:07But you could navigate with them. You could survey with them. You could also keep time with them because you just adjust the astrolabe to mimic the stars or something like that. and you can be like, oh, it's 2.30. It's sandalwood time. That's right. It's sandalwood time. Then we finally get to the hourglass. But later than you think, and especially, and I'm glad Livia dug deep because she's a great researcher, but if you just sort of do cursory Internet research, you might find a lot of people saying it's ancient Egypt. But that's probably not the case. It's actually much later than that, probably the late medieval period that hourglasses came along.

20:42And actually after the mechanical clock, That's nuts. The earliest known reference is in Italy in 1338. And you think an hourglass is pretty easy to make? Like, you know, you just blow the glass in a certain way and throw the sand in there. But sand is finicky, as you know, as far as humidity and moisture goes. So you had to get the sand in there and you had to seal it up. But you couldn't seal it up with any kind of moisture because it would clump up. So it's a little trickier to make an hourglass than you might imagine. Yeah. When it's humid out, the soap opera days of our lives never get started.

21:17Right. It's sad. Was that the one you watched in college? I think that's what people wrote in and said, yeah, I'm pretty sure. I couldn't remember. Okay. So one of the other things humans do when they have an invention that's popular and widespread, they don't just shrink it down to a miniature portable size. They also just show off. Yeah. They do whatever they can to make it even cooler. And there were a succession of inventors in different parts of the world over the years that did some really neat stuff with, say, like water clocks. One was a guy named Andronikos. He was from Macedonia. And he built what's called the Tower of Winds in Athens.

22:00It's this, I think, hexagon or octagon made of marble that's 15 meters or about 45 feet tall. It's still standing. But when it was in use, it had water clocks, it had sundials. You could gauge the wind. You could tell what was going on celestially. He just basically packed every neato timekeeping invention that was around at the time into this thing. Yeah, and like you said, a lot of people just started getting just sort of fancy with it and actually just really creative. In 8th century CE, there was a Chinese Buddhist monk who, along with his colleagues, created a clock that was a water-powered wheel, had a gear system.

22:41This is when gears really started becoming a huge thing in timekeeping. And it did a single rotation every 24 hours, which you think, like, all right, that just sounds sort of regular. But it also had, like, bells chiming on the hour, and it had a drumbeat that chimed every quarter hour. So this is when, like, kind of hearing chimes and things to tell you what time it was came in. It went ba-dun-ch every 15 minutes. That's right. There's a guy named Su Sung who is very famous for his 35-foot, I also saw it described as 40-foot clock tower. One of the things it did were there were mannequins that came out and rang gongs.

23:19Yeah. Like you usually associate this with like maybe some sort of cuckoo clock or something like that. This is from the 11th century. So it's pretty impressive that he came up with this. And again, it was a water clock. Like this is running on water. And then someone else who put water clocks to great use was just this amazing inventor and engineer. His name was Ismail Al-Jazari. He was from Upper Mesopotamia. And his whole thing was not just accurate clock timekeeping, but just essentially delightful little add-ons that did some cool stuff. He created what's called the castle clock. That's pretty neat.

24:01But for my money, look up the elephant clock. There's a life-size replica of it at a museum, I think, in Saudi Arabia. And you can see, you know, how it works and what it does. But essentially, water just moves from part to part. There's a scribe in the middle riding on the elephant. There's another person on the front of the elephant driving it. There's another guy way up that plays cymbals and stuff. it's just amazing especially when you learn about how every single step works yeah that thing you sent that to me that was super cool looking yeah very ornate now we kind of get to the point should we break or can we keep going yeah let's take a break all right we'll be right back learn to stop with Joshua and Charles stuff you should know

25:03All right, so we're back to wrap it up on clocks and eventually, spoiler, watches. But we're at the point now where clocks kind of start ticking, and we're getting closer and closer to keeping track of seconds, although that'll be a second till we get to it. But as for mechanical clocks go, those water-powered Chinese clocks arguably were the first mechanical clocks. And again, it's one of those things where they don't know if people invented these in Europe or their Muslim world at the same time, or if it kind of spread out from one place to another. Another origin story is maybe mechanical clocks came from Europe with, would it be Gerbert?

25:46I think so. Gerbert of Aurelac, who was a French scholar, but you might know him a little better as Pope Sylvester II. Oh, okay. Because he would become Pope later on. He developed, I guess in his pre-Pope days, a mechanical timekeeping device, like truly mechanical in 996 CE. But then it took a few hundred years for it to become, like for mechanical clocks to become a real thing. It didn't really catch on. Right, which makes some people suspect that he might not have actually done that. Yeah. So what's happened here, I guess, we've transitioned from tracking the movement of water to track time to actually using the kinetic energy in water that's, say, flowing downhill to run gears and stuff like that.