WEBVTT - Weather Tech, Part 1 0:00:04.519 --> 0:00:14.360 Technology, Tech Stuff from stuff either and welcome to Tech Stuff. 0:00:14.400 --> 0:00:17.439 I am your host Jonathan Strickland joining me in the 0:00:17.480 --> 0:00:21.119 studio today our friend Dylan. Hi. Dylan, Hi. We're not 0:00:21.200 --> 0:00:24.560 talking about photo editing today. We are not. No, We're 0:00:24.640 --> 0:00:27.120 we're talking. Uh, you know, let's do some small talk. 0:00:28.080 --> 0:00:34.159 How's the weather. Well today it is overcast and uh, 0:00:34.440 --> 0:00:36.839 I believe there's a thirty percent chance of rain. Yeah, 0:00:36.880 --> 0:00:39.200 it's a little breezy. We went up to the roof 0:00:39.280 --> 0:00:43.199 of the building and re enacted parts of Titanic. I 0:00:43.280 --> 0:00:46.400 spread my arms and Dylan held me and I said 0:00:46.440 --> 0:00:49.560 I was king of the world. They told me to 0:00:49.560 --> 0:00:53.200 go back downstairs. No, uh, we're talking about whether not 0:00:53.280 --> 0:00:57.440 because I like terrible small talk, although I'm adept at it, 0:00:57.960 --> 0:01:01.200 but because of a listener request. Uh. This comes from 0:01:01.440 --> 0:01:05.720 Dress Sayan and Dress, I am so sorry if I 0:01:05.760 --> 0:01:08.800 mispronounced your name. I actually asked Drees how to pronounce 0:01:09.000 --> 0:01:12.360 this name, and I can only hope I got close. 0:01:12.600 --> 0:01:15.440 But here's what Dres had to say. Hey, I just 0:01:15.440 --> 0:01:18.959 wanted to ask slash request something about the podcast. See 0:01:18.959 --> 0:01:20.959 a while back, I had a conversation with my dad. 0:01:21.120 --> 0:01:24.280 He commented how amazing it was these days, he can 0:01:24.319 --> 0:01:27.280 just check a website that will pretty accurately tell him 0:01:27.360 --> 0:01:29.920 whether it's going to rain in the next few hours. 0:01:30.040 --> 0:01:33.279 And where I said that, it doesn't seem like that's 0:01:33.520 --> 0:01:35.959 amazing progress to me. After all, when he was a 0:01:36.000 --> 0:01:38.560 kid in the sixties, they wrote would report if it 0:01:38.600 --> 0:01:41.360 would rain the next day, and now it's just that 0:01:41.400 --> 0:01:43.240 we've got it down to a few hours instead of 0:01:43.280 --> 0:01:45.640 twenty four hours ahead. He laughed and said the weather 0:01:45.640 --> 0:01:48.080 report back then was pretty much a joke. Anyway, this 0:01:48.160 --> 0:01:49.680 gave me a lot to think about, and it seemed 0:01:49.680 --> 0:01:51.880 like something to learn about from the Tech Stuff podcast, 0:01:52.080 --> 0:01:54.080 because to be honest, I have no clue how weather 0:01:54.240 --> 0:01:57.080 is accurately predicted. It's just always been there for me. 0:01:57.480 --> 0:02:03.280 So we're gonna talk about weather forecasting, meteorology, the technology 0:02:03.400 --> 0:02:07.480 used to UH to to make predictions, UM, what those 0:02:07.520 --> 0:02:11.960 predictions actually mean. We're gonna break all that down. UH. 0:02:12.000 --> 0:02:15.160 There will probably be at least one or two references 0:02:15.240 --> 0:02:20.320 to how weather report. Weather reports are still largely the 0:02:20.360 --> 0:02:24.160 work of some estimations and best guesses, because, as it 0:02:24.200 --> 0:02:28.200 turns out, whether it's incredibly complicated, but hopefully by the 0:02:28.280 --> 0:02:30.040 end of it you'll have a little bit more sympathy 0:02:30.320 --> 0:02:34.280 for meteorologists, right right, as opposed to my friend who 0:02:34.360 --> 0:02:38.840 in college wrote an essay explaining what level of hell 0:02:39.000 --> 0:02:44.600 meteorologists should inhabit based upon Dante's Inferno, which was kind 0:02:44.600 --> 0:02:48.840 of funny, but also I'm sure meteorologists find it less. So. 0:02:49.240 --> 0:02:52.400 Uh So, let's start off with just talking about the 0:02:52.560 --> 0:02:56.840 history of of predicting weather, and really you have to 0:02:56.840 --> 0:02:59.880 go all the way back to early human civilization because, 0:03:00.000 --> 0:03:02.919 as it turns out, one of the most important factors 0:03:02.919 --> 0:03:04.960 that play a part in this is the fact that 0:03:05.000 --> 0:03:09.919 we humans are pretty good at recognizing patterns. Right, So 0:03:10.320 --> 0:03:12.840 when something happens over and over, we take note of it, 0:03:12.960 --> 0:03:15.120 and we start to look at the other things that 0:03:15.160 --> 0:03:17.960 are happening over and over, and then we start to 0:03:18.040 --> 0:03:22.480 draw some hypotheses. For example, we might think that one 0:03:22.600 --> 0:03:26.640 thing could cause the next thing, or we might think 0:03:26.919 --> 0:03:30.680 one thing simply indicates the next thing is going to happen. Um, 0:03:30.720 --> 0:03:33.320 here's a simple example. Let's say that you are a 0:03:33.360 --> 0:03:37.320 shepherd and you notice that the flock of sheep act 0:03:37.440 --> 0:03:41.080 in a certain odd way every time it's about to rain. 0:03:41.560 --> 0:03:44.120 You might either come to the conclusion that the sheep 0:03:44.160 --> 0:03:46.760 are able to sense the rain before it actually happens, 0:03:46.800 --> 0:03:49.160 and therefore that as an indicator that is going to rain, 0:03:49.880 --> 0:03:51.520 or you might come to the conclusion that, in fact, 0:03:51.560 --> 0:03:54.880 the sheep are causing it to rain. That's probably not 0:03:55.040 --> 0:03:59.480 true that yeah, yeah, so. But eventually you through these 0:03:59.560 --> 0:04:02.480 up survey you start to eliminate possibilities and you start 0:04:02.520 --> 0:04:07.320 to draw some conclusions. Now, in early human civilizations, we're 0:04:07.320 --> 0:04:11.680 talking about very broad conclusions. Things like you notice that 0:04:12.000 --> 0:04:16.160 in general, the weather gets cooler as the year goes on. 0:04:16.640 --> 0:04:18.240 You might not even have a year at this point. 0:04:18.240 --> 0:04:20.920 You may just think, as time passes, the weather gets 0:04:20.920 --> 0:04:23.360 cooler until it gets really cold, and after it's really 0:04:23.400 --> 0:04:25.919 cold for a while, it starts to get warm again, 0:04:25.960 --> 0:04:28.239 and then it gets really warm, and then it gets hot, 0:04:28.600 --> 0:04:31.000 and then the whole cycle starts over. And you may 0:04:31.040 --> 0:04:34.479 also notice that the stars, the way the stars are, 0:04:34.800 --> 0:04:37.760 you can tell that they are. It's a slightly different 0:04:37.880 --> 0:04:42.040 view as this time goes on, and you start to associate, oh, 0:04:42.120 --> 0:04:44.720 when the stars get into this slow you know, this 0:04:44.839 --> 0:04:48.320 kind of configuration, it means we're getting towards the time 0:04:48.640 --> 0:04:52.440 when we should really harvest uh food, because we're about 0:04:52.480 --> 0:04:54.960 to go into the winter months and otherwise we're going 0:04:55.000 --> 0:04:58.400 to lose everything we've been growing. Or when when it's 0:04:58.520 --> 0:05:00.880 this time, we should start playing n ting food because 0:05:00.880 --> 0:05:02.920 it's the best time for us to get a big 0:05:03.000 --> 0:05:07.599 yield later on climate. Yeah, and you start to figure 0:05:07.600 --> 0:05:10.039 out you build out a calendar based on this, and 0:05:10.040 --> 0:05:13.160 that calendar would be fairly rough, you know, wouldn't necessarily 0:05:13.200 --> 0:05:16.200 be reflective of an actual full year, but it would 0:05:16.200 --> 0:05:19.440 be more like an indicator of what you should be 0:05:19.480 --> 0:05:23.520 expecting in the next coming time. Right, So that's your 0:05:23.520 --> 0:05:27.000 basic like big picture stuff, using things like the way 0:05:27.040 --> 0:05:30.760 animals react or certain smells that you might detect before 0:05:30.800 --> 0:05:34.159 a rainstorm. That would be sort of the more acute 0:05:34.960 --> 0:05:37.599 weather type stuff as opposed to the seasonal type stuff. 0:05:37.960 --> 0:05:41.320 And you start to draw those conclusions too, and together 0:05:41.400 --> 0:05:45.560 you start building out general rules that tell you if 0:05:45.800 --> 0:05:49.160 this one thing is happening, then here's what you should expect. 0:05:49.240 --> 0:05:53.400 This sort of pattern recognition. Um. And in fact, today 0:05:53.960 --> 0:05:58.920 some of our data still relies on that principle. It's 0:05:58.960 --> 0:06:01.680 just that we have way more information now at a 0:06:01.800 --> 0:06:06.839 much higher precision than ancient humans did. And and speaking 0:06:06.880 --> 0:06:11.080 of that, I read UM that there are certain Aboriginal 0:06:11.120 --> 0:06:15.000 tribes have been observing their weather patterns for over eighteen 0:06:15.080 --> 0:06:17.800 thousand generations, so that kind of gives you a sense 0:06:17.839 --> 0:06:20.760 of how far back this goes. Yeah, and and of course, 0:06:20.800 --> 0:06:24.200 you know, if you're talking about a very specific region, 0:06:24.360 --> 0:06:30.479 like a very uh, relatively small geographic area, you could 0:06:30.560 --> 0:06:34.120 have a pretty accurate idea of what to expect based 0:06:34.200 --> 0:06:38.080 upon those sorts of observations. Um, they might not be 0:06:38.279 --> 0:06:42.120 presented in the super cool, high tech way that that 0:06:42.320 --> 0:06:46.520 modern meteorology tends to present it, but that doesn't make 0:06:46.560 --> 0:06:50.200 it any less valid. Necessarily. It may be a little 0:06:50.320 --> 0:06:52.320 more rough around the edges. But if you can still 0:06:52.360 --> 0:06:54.240 tell me that, hey, in three days we're gonna get 0:06:54.240 --> 0:06:56.919 some rain, and three days later it rains, and you 0:06:56.960 --> 0:07:03.040 do that reliably, that's pretty impressive. Right. So, uh, if 0:07:03.040 --> 0:07:04.960 you want to start looking at people who were really 0:07:04.960 --> 0:07:09.600 thinking about whether in kind of almost a scientific sense, 0:07:10.640 --> 0:07:12.200 and one of the first people you would have to 0:07:12.200 --> 0:07:16.960 look at his Aristotle. Um, big brain Aristotle, he was. 0:07:17.680 --> 0:07:23.400 He was quite the thinker. He wrote about whether in Meteorologica, 0:07:24.280 --> 0:07:27.560 and he came up with a bunch of hypotheses, some 0:07:27.720 --> 0:07:31.200 column theories, I would say, hypotheses because none of these, 0:07:31.360 --> 0:07:33.440 not all of these proved true, but came up with 0:07:33.480 --> 0:07:36.120 some hypotheses about how stuff like rain and hail and 0:07:36.200 --> 0:07:40.000 wind and clouds and thunder and lightning and hurricanes, what 0:07:40.160 --> 0:07:42.840 made them happen, how did they behave what were the 0:07:42.920 --> 0:07:46.320 rules that governed them? And some of his ideas were 0:07:46.480 --> 0:07:49.840 mostly right and some of his ideas were way off. 0:07:50.280 --> 0:07:54.880 But the problem was without ways to measure the various 0:07:54.920 --> 0:07:58.960 metrics associated with weather, it was kind of impossible to 0:07:58.960 --> 0:08:01.200 say one way or the other. So for about two 0:08:01.200 --> 0:08:04.920 thousand years, everyone kind of just went with it because 0:08:05.120 --> 0:08:08.880 you didn't have any way of proving or disproving any 0:08:08.920 --> 0:08:13.360 of the individual ideas. But you need you need a basis. Yeah, 0:08:13.400 --> 0:08:16.240 you know, at least it was something. It was at 0:08:16.320 --> 0:08:18.040 least something to work from. It was just it was 0:08:18.080 --> 0:08:21.640 just a question of time. When would people develop tools 0:08:22.080 --> 0:08:24.240 that would allow them to put these ideas to the 0:08:24.280 --> 0:08:28.160 test and either uh, see which ones are mostly right 0:08:28.240 --> 0:08:30.360 but maybe need some tweaking, or which ones you can 0:08:30.400 --> 0:08:34.000 just completely throw out the window, Which brings us up 0:08:34.000 --> 0:08:38.240 to the Renaissance, one of my favorite time periods. As 0:08:38.240 --> 0:08:41.120 it turns out, spent a lot of time there. Our 0:08:41.160 --> 0:08:45.640 listeners can't see. But right now Jonathan has a handlebar mustache, 0:08:45.920 --> 0:08:49.720 a giant handlebar mustache. Because the character I play in 0:08:49.760 --> 0:08:54.240 the Georgia Renaissance Festival has such a mustache. And uh, 0:08:54.280 --> 0:08:57.400 and I will be performing as that character the day 0:08:57.480 --> 0:09:01.320 after we record this episode. It's a weekend for the 0:09:01.320 --> 0:09:04.840 Georgia Renaissance festivals. Would you say that someone might have 0:09:04.920 --> 0:09:08.560 a handlebar mustache in the fifteenth century, around the time 0:09:08.600 --> 0:09:13.920 of German philosopher Nicholas of Cusa, It's quite possible. Um, 0:09:13.960 --> 0:09:16.920 I mean, there's no reason they could not have one. 0:09:17.440 --> 0:09:21.760 What's not like there were social taboos about such things. Uh. Yeah, 0:09:21.800 --> 0:09:25.360 So this philosopher, Nicholas of Cusa, designed a device to 0:09:25.400 --> 0:09:28.560 measure the amount of moisture in the air. Uh. And 0:09:28.679 --> 0:09:32.640 we call these hygrometers. These are it's really kind of 0:09:32.640 --> 0:09:36.400 a way of measuring humidity, which here in Atlanta you 0:09:36.400 --> 0:09:41.280 can pretty much just say it's it's humid. It's so humid. Yeah, 0:09:41.360 --> 0:09:44.200 the humidity in Atlanta is brutal, to the point where 0:09:44.240 --> 0:09:47.320 I have friends who come in from Texas where the 0:09:47.360 --> 0:09:50.160 temperatures and Texas can get twenty degrees hotter than it 0:09:50.200 --> 0:09:53.319 gets here in Atlanta. But because Texas has relatively low 0:09:53.400 --> 0:09:56.880 humidity through most of the state, they think the weather 0:09:57.040 --> 0:10:01.160 here is way worse, like, way more difficult to deal with. 0:10:01.640 --> 0:10:03.960 But how do you measure that? And he came up 0:10:04.000 --> 0:10:06.920 with an interesting idea. Now there's no there's no indication 0:10:06.960 --> 0:10:09.800 that he ever built the device he came up with, 0:10:09.880 --> 0:10:12.040 but he said, what you do is you take a 0:10:12.080 --> 0:10:14.959 set of balanced scales, so you know what those look like. 0:10:15.000 --> 0:10:18.120 They have a little dish on either side, and on 0:10:18.120 --> 0:10:21.360 one side you put a large amount of wool, and 0:10:21.400 --> 0:10:23.679 on the other side you put some some weights. He 0:10:24.120 --> 0:10:28.160 said stones. Other people later on said discs of wax 0:10:28.320 --> 0:10:30.120 didn't really matter. It just had to be a counterweight 0:10:30.160 --> 0:10:33.440 of some sort. Now, the purpose of the wool is 0:10:33.480 --> 0:10:37.679 to soak up moisture in the atmosphere, which would make 0:10:37.760 --> 0:10:40.560 the wool get heavier. This is what Nicholas was saying, Like, 0:10:40.600 --> 0:10:43.240 the wool will get heavier as it soaks up water 0:10:43.360 --> 0:10:46.120 from the air, and you'll be able to tell that 0:10:46.280 --> 0:10:50.400 because the scales will start to shift and you'll see 0:10:50.400 --> 0:10:52.520 that the the side with the wool will start to 0:10:52.559 --> 0:10:55.920 get heavier. Then if it dries out, if the weather 0:10:55.960 --> 0:11:00.040 gets dry, the wool will start to lose moisture, it 0:11:00.040 --> 0:11:02.160 will evaporate, and you'll start to see that side of 0:11:02.200 --> 0:11:05.320 the scale moving up. It'll get lighter. Now, he never 0:11:05.360 --> 0:11:09.840 built that, but another big thinker of the Renaissance did 0:11:10.000 --> 0:11:15.920 get around to it, Leonardo da Vinci. He did everything. Yeah, 0:11:16.280 --> 0:11:21.040 when he wasn't building helicopters or designing tanks, which he 0:11:21.120 --> 0:11:23.200 never built, but he did design. He designed a tank, 0:11:23.200 --> 0:11:28.000 and he designed a really weird um I think gosh, 0:11:28.000 --> 0:11:31.079 it was something like a thirty three barrel gun didn't 0:11:31.080 --> 0:11:34.760 eat the I think a diving suit as well. Pretty 0:11:34.840 --> 0:11:38.760 much any any sort of thing that in the Renaissance 0:11:38.760 --> 0:11:41.480 would sound like it's science fiction that she had some 0:11:41.520 --> 0:11:43.920 sort of hand in. He probably has a primitive tablet 0:11:44.000 --> 0:11:47.840 schematic somewhere. Yeah, yeah, he probably at one point came 0:11:47.880 --> 0:11:52.640 out to his patrons and showed a wooden slate and 0:11:52.679 --> 0:11:55.240 talked about how if you ran your fingers across it, 0:11:55.320 --> 0:11:58.040 you could, uh, you could pageanate through. And then he'd say, 0:11:58.400 --> 0:12:01.000 I think you're gonna love it, and maybe even did 0:12:01.040 --> 0:12:06.400 a one more thing. Um So that was the first 0:12:06.559 --> 0:12:11.439 kind of weather related um uh instrument that people were 0:12:11.440 --> 0:12:15.320 really thinking about. Another would come in the seventeenth century. 0:12:15.640 --> 0:12:20.439 Early sires usually put around sixteen o three when physicist 0:12:20.480 --> 0:12:24.000 Galileo Galile created a thermoscope, which is sort of a 0:12:24.040 --> 0:12:26.800 predecessor to a thermometer. And it was a pretty simple idea. 0:12:26.840 --> 0:12:28.800 So you start with a container that has a small 0:12:28.840 --> 0:12:32.360 amount of liquid in it, usually water. That's your base. 0:12:33.080 --> 0:12:36.360 And then you also have a kind of a hollow 0:12:36.520 --> 0:12:40.960 tube of glass that ends in a bulb, so like 0:12:41.040 --> 0:12:44.120 a larger bulb at one end and open on the 0:12:44.160 --> 0:12:48.520 other end, and you could do something like warm the 0:12:48.640 --> 0:12:50.880 bulb if you want to, in your hands. But then 0:12:50.920 --> 0:12:53.880 you would put the bulb, you put the tube into 0:12:53.960 --> 0:12:56.520 the small container of water. The bulb would be suspended 0:12:56.520 --> 0:13:02.800 above it. Usually the hollow uh straw like tube would 0:13:02.840 --> 0:13:05.439 be long enough, you know, several inches long. You could 0:13:05.480 --> 0:13:08.720 then observe that as the temperature of the bulb changed, 0:13:09.040 --> 0:13:11.440 the level of water in the tube would either go 0:13:11.559 --> 0:13:14.720 up or go down. And this is because the air 0:13:14.840 --> 0:13:18.720 inside the tube is either expanding or contracting, depending upon 0:13:19.600 --> 0:13:22.720 whether it's heating up or cooling down. And this wasn't 0:13:22.720 --> 0:13:25.320 a thermometer, but it was it was interesting, and it 0:13:25.400 --> 0:13:30.120 was once again a start. Yeah, later on someone looked 0:13:30.160 --> 0:13:34.320 at Galileo's little invention and said, what if we put 0:13:34.320 --> 0:13:38.000 like markings on the tube so you could say how 0:13:38.000 --> 0:13:41.600 many steps up or down the tube it went. Then 0:13:41.640 --> 0:13:45.040 we could even give indications of how much warmer or 0:13:45.120 --> 0:13:47.720 cooler a guy. You could say that it's four steps 0:13:47.760 --> 0:13:51.040 warmer or four steps cooler. That became the basis of 0:13:51.080 --> 0:13:54.560 the thermometer. So and that didn't take long. It was 0:13:54.679 --> 0:13:57.600 within about fifty years that that you had the first 0:13:57.679 --> 0:14:03.040 working thermometers. Following this this kind of proof of concept thermoscope, 0:14:03.080 --> 0:14:06.920 there was also there is the Galilean thermometer. Are you 0:14:06.920 --> 0:14:11.800 familiar with these? You've probably seen one. They are the 0:14:11.920 --> 0:14:17.080 cylindrical glass. They're usually very decorative for for like home 0:14:17.080 --> 0:14:20.239 office deskers, and but there these glass tubes. They are cylindrical. 0:14:20.440 --> 0:14:24.440 Typically inside they have these these little glass blown glass 0:14:24.520 --> 0:14:28.240 balls that contain their own liquid. Often it's a liquid 0:14:28.280 --> 0:14:30.880 that has dye in it, so they're blue or green 0:14:31.000 --> 0:14:33.280 or red or whatever. And each one has a little 0:14:33.320 --> 0:14:37.520 weight attached to it that has a temperature. And what 0:14:37.680 --> 0:14:42.880 happens is the balls represent different densities of water, and 0:14:42.960 --> 0:14:48.440 the temperature of the glass tube will change the density 0:14:48.480 --> 0:14:51.760 of the water inside the glass tube, and then you'll 0:14:51.760 --> 0:14:55.960 see whichever ball is at the bottommost of the tube 0:14:56.160 --> 0:15:00.160 the glass tube, as that represents the general temperature, and 0:15:00.160 --> 0:15:02.040 they tend to be between like you know, like about 0:15:02.080 --> 0:15:04.200 five degrees apart, so you might have sixty five degrees 0:15:04.240 --> 0:15:07.080 seventy seventy five degrees eighty that kind of thing. So 0:15:07.080 --> 0:15:10.520 whicheveryone's at the lowest point, that's the temperature of the water, 0:15:10.680 --> 0:15:15.000 thus the temperature of the areas surrounding it. I tend 0:15:15.040 --> 0:15:16.920 to be used, like I said, as decorations for desks 0:15:16.920 --> 0:15:20.440 and stuff. Galileo actually did not invent that, but some 0:15:20.520 --> 0:15:22.760 of his students did. It was several of his students, 0:15:22.800 --> 0:15:27.200 so that's why it's called a Galilean thermometer's neat. Yeah. Yeah, 0:15:27.240 --> 0:15:31.680 it's a very pretty way of seeing, generally speaking, what 0:15:31.760 --> 0:15:37.120 temperature the tube is and therefore probably what temperature the 0:15:37.120 --> 0:15:40.200 surrounding air is. Keeping in mind that water changes temperature 0:15:40.240 --> 0:15:43.720 more slowly than uh than something like a room would, 0:15:43.880 --> 0:15:46.600 so it wouldn't be reflected immediately, but it's still kind 0:15:46.600 --> 0:15:49.160 of interesting. Then we have the barometer. This is a 0:15:49.280 --> 0:15:54.280 very important tool in uh predicting the weather. So barometer 0:15:54.320 --> 0:15:57.720 is all about predicting or not predicting, but measuring atmospheric pressure. 0:15:58.720 --> 0:16:02.760 So first, just in case you weren't aware, the atmosphere 0:16:03.000 --> 0:16:06.600 exerts pressure on us. It pushes down. Gravity is technically 0:16:06.640 --> 0:16:10.400 pulling down on the atmosphere. So the lower you are 0:16:11.320 --> 0:16:13.360 to the surface of the air, like the closer the 0:16:13.400 --> 0:16:17.040 lower down in elevation you are, the more pressure you 0:16:17.080 --> 0:16:20.600 feel from atmosphere. This is why as you climb a mountain, 0:16:21.480 --> 0:16:25.120 where you get on a plane, you experience lower amounts 0:16:25.120 --> 0:16:27.200 of air pressure. It's also why you have to pressure 0:16:27.240 --> 0:16:30.280 eze aircraft that fly it pretty high altitudes, otherwise you 0:16:30.280 --> 0:16:35.080 would suffer some pretty rough effects. Um. And on the 0:16:35.160 --> 0:16:39.320 Earth surface, the force of gravity. Due to the force 0:16:39.320 --> 0:16:42.760 of gravity, the pressure is about fourteen points seven pounds 0:16:42.800 --> 0:16:45.200 per square inch. Yeah, that's a sea level. Yeah, that's 0:16:45.200 --> 0:16:48.440 what we call an atmosphere of pressure. Right one atmosphere 0:16:48.440 --> 0:16:51.360 of pressure. You look at it at sea level. Specifically, 0:16:51.360 --> 0:16:53.760 you're looking at it at sea level at fifty nine 0:16:53.800 --> 0:16:57.120 degrees fahrenheit, which is fifteen degrees celsius. Uh. You have 0:16:57.160 --> 0:17:00.120 to be very specific because temperature will change pressure as 0:17:00.280 --> 0:17:03.960 as you warm up air. Uh. Typically this is just 0:17:04.000 --> 0:17:07.080 a general rule of thumb. When something warms up, that 0:17:07.160 --> 0:17:12.120 means molecules are moving. That's that's the energy of motion. Ultimately, 0:17:12.119 --> 0:17:15.000 you're making these molecules move faster, and that's kind of 0:17:15.359 --> 0:17:20.200 what heat looks like. So as molecules of air move 0:17:20.480 --> 0:17:24.320 around more, they spread out more, it becomes less dense. 0:17:24.800 --> 0:17:27.600 So that would change the atmospheric pressure as well. That's 0:17:27.600 --> 0:17:30.040 why you have to take temperature into account. When you 0:17:30.080 --> 0:17:34.160 talk about one atmosphere of pressure. That's very specific. It's 0:17:34.200 --> 0:17:39.400 at sea level at that temperature, that's one atmosphere um 0:17:39.560 --> 0:17:42.119 So that's that's kind of interesting. Anyway. The first person 0:17:42.160 --> 0:17:44.800 to actually create a barometer, it was a guy by 0:17:44.800 --> 0:17:50.080 the name of Evangelista Toricelli, and h the first invention 0:17:50.119 --> 0:17:55.480 people just called tori Chelli's tube, which doesn't seem very dignified. No, 0:17:55.640 --> 0:17:58.560 it needs a special name, Yeah, but tore Chelli's tube, 0:17:58.600 --> 0:18:00.960 it wasn't quite the barometer yet. What he was doing 0:18:01.040 --> 0:18:04.840 was he was actually experimenting with the concept of vacuums, 0:18:04.880 --> 0:18:08.600 like creating a vacuum within an within a tube or 0:18:08.680 --> 0:18:11.280 some other container. He was just it was one of 0:18:11.280 --> 0:18:14.199 those things where we didn't fully understand what that was 0:18:14.320 --> 0:18:17.159 how it worked, and so he did this experiment. He 0:18:17.160 --> 0:18:22.040 was actually friends with Galileo, and Galileo said, hey, Evangelista, 0:18:22.200 --> 0:18:24.040 I got an idea for you. Why don't you take 0:18:24.119 --> 0:18:25.960 one of those tubes you've been working with and fill 0:18:26.000 --> 0:18:29.880 it with mercury and use that in your vacuum experiments. 0:18:29.880 --> 0:18:32.320 Will be a lot easier to see than some other liquid. 0:18:32.440 --> 0:18:34.399 And toward Cheli says, all right, I'll give it a shot. 0:18:34.680 --> 0:18:37.000 So he took a four ft long glass tube and 0:18:37.040 --> 0:18:39.080 he filled the glass tube with mercury so it was 0:18:39.080 --> 0:18:41.520 closed on one end, open on the other, and then 0:18:41.520 --> 0:18:44.920 he inverted the tube into a dish, and the dish 0:18:44.920 --> 0:18:46.720 had a little bit of mercury at the bottom of it, 0:18:46.760 --> 0:18:49.480 and it showed that despite the fact that the top 0:18:49.520 --> 0:18:51.959 of the tube, you know, like the mercury went all 0:18:52.000 --> 0:18:55.000 the way up this four foot tube, the liquid didn't 0:18:55.080 --> 0:18:58.639 just come rushing out and spill everywhere, right, because the 0:18:58.720 --> 0:19:01.760 vacuum is what held it him place. And he says, look, see, 0:19:01.920 --> 0:19:05.960 I was so smart. This shows that there's something working here. 0:19:06.040 --> 0:19:09.400 We're gonna really explore this. But then he noticed something 0:19:09.440 --> 0:19:12.000 else that was really interesting. He noticed that despite the 0:19:12.000 --> 0:19:15.760 fact that the tube could stay upright and the liquid 0:19:15.800 --> 0:19:18.600 would stay in there. From day to day, there are 0:19:18.640 --> 0:19:21.600 variations and how high the mercury would be in the tube. 0:19:21.960 --> 0:19:23.879 And it wasn't just sinking down. It's not like it 0:19:23.920 --> 0:19:26.919 was leaking over the course of a week. So like 0:19:26.960 --> 0:19:28.639 you come back and it's a couple inches lower, and 0:19:28.640 --> 0:19:30.080 then the next day it's a couple of inches lower. 0:19:30.119 --> 0:19:31.960 It wasn't like that. Some days it was actually higher. 0:19:32.800 --> 0:19:35.280 And he started thinking, well, what the heck would cause 0:19:36.040 --> 0:19:39.280 the mercury to go up or down this tube. The atmosphere, 0:19:39.520 --> 0:19:43.520 that's it. The atmospheric pressure pressing down on the liquid 0:19:43.520 --> 0:19:47.840 in the dish. That's what determined whether the the well, 0:19:47.880 --> 0:19:50.600 that's what determined the height of the mercury inside the tube. 0:19:50.920 --> 0:19:54.919 So on days with higher atmospheric pressure, it pushes down 0:19:54.960 --> 0:19:58.119 on that that exposed liquid within the dish, and it 0:19:58.280 --> 0:20:02.160 forces that liquid to go up the tube, and and 0:20:02.200 --> 0:20:04.480 so the height of the liquid inside the tube goes up. 0:20:05.040 --> 0:20:08.120 On days where atmospheric pressure is lower, some of that 0:20:08.240 --> 0:20:11.840 liquid comes down and starts filling up the dish until 0:20:11.920 --> 0:20:15.840 it reaches that kind of equilibrium. And then he so 0:20:15.920 --> 0:20:19.080 he said, hey, this shows that the atmosphere itself exerts pressure. 0:20:19.160 --> 0:20:23.040 And not only that, but the pressure is not consistent 0:20:23.320 --> 0:20:28.520 day to day, can change. And uh in Torchelli built 0:20:28.560 --> 0:20:31.320 the first mercury barometer, So now he was building something 0:20:31.359 --> 0:20:34.640 specifically to measure this thing, because before he was really 0:20:34.880 --> 0:20:40.560 demonstrating the concept of vacuums. So now we've got the barometer, 0:20:40.680 --> 0:20:44.520 we've got the thermometer, we've got the hygrometer, essential things. Yeah, 0:20:44.520 --> 0:20:49.240 these are the basics for taking measurements about weather. And 0:20:49.880 --> 0:20:55.760 at that point it was really the start of gathering 0:20:55.840 --> 0:20:59.040 enough information so that meteorology, the science of meteorology, could 0:20:59.040 --> 0:21:03.520 actually exist, right because now we could not just observe patterns, 0:21:03.920 --> 0:21:09.280 we could actually quantify what was happening. And by quantifying it, 0:21:09.359 --> 0:21:11.200 we could get to this level of precision where we 0:21:11.240 --> 0:21:17.480 could start to draw more uh uh specific conclusions as 0:21:17.480 --> 0:21:21.000 to what would or would not happen based upon current conditions. 0:21:21.640 --> 0:21:25.840 So all that being said, we still have some issues 0:21:25.920 --> 0:21:28.439 predicting weather. So why is that? Well, like I said before, 0:21:29.800 --> 0:21:36.200 it's complicated. So here's the thing. Our atmosphere is fluid. 0:21:36.359 --> 0:21:42.040 It's a gas, but it behaves via fluid dynamics. Dylan, 0:21:42.080 --> 0:21:46.600 have you ever studied fluid dynamics. I studied them in physics, 0:21:46.640 --> 0:21:51.159 and they are brutally difficult to comprehend because it can 0:21:51.200 --> 0:21:56.320 get so there's so many factors that can affect a 0:21:56.400 --> 0:21:59.439 fluid so and the Earth has a whole bunch of 0:21:59.440 --> 0:22:02.399 them happening at once. Right. First of all, there's this 0:22:02.440 --> 0:22:08.600 big ball of plasma that's about eight and a half 0:22:08.880 --> 0:22:14.159 light minutes away from us. It's called the Sun. Yeah, 0:22:13.400 --> 0:22:16.240 uh you know, on on nice days you might even 0:22:16.240 --> 0:22:19.760 get a glimpse of it. So the Sun provides obviously 0:22:19.840 --> 0:22:23.080 a ton of energy to the Earth and uh so 0:22:23.160 --> 0:22:25.600 we so the Earth absorbs a lot of solar radiation 0:22:26.160 --> 0:22:28.520 and that can affect fluid dynamics because you've got a 0:22:28.560 --> 0:22:32.000 lot of heat coming into a system. On top of that, 0:22:32.080 --> 0:22:35.119 you've got the Earth there. It's not standing still, the 0:22:35.160 --> 0:22:41.040 Earth's rotating. That rotational force creates other fluid i effects 0:22:41.520 --> 0:22:44.399 in the atmosphere. We'll talk about those specifically. When we 0:22:44.400 --> 0:22:49.280 get too high and low pressure systems. Um you've got gravity, 0:22:49.359 --> 0:22:52.879 which is pulling down on the fluid, so that's another 0:22:52.920 --> 0:22:56.760 force that's in play. You've got differences in surface temperature 0:22:56.840 --> 0:22:59.480 on the Earth, so you've got areas where it's very cold, 0:22:59.560 --> 0:23:02.119 versus are is that are very hot that in turn 0:23:02.200 --> 0:23:06.159 affects the atmosphere and can change things around. You have 0:23:06.240 --> 0:23:09.680 air currents, a big deal there. That's also partially due 0:23:09.680 --> 0:23:12.080 to the rotation of the Earth. You've got mountain ranges 0:23:12.119 --> 0:23:14.720 which can act as like a windbreaker for certain things. 0:23:14.800 --> 0:23:18.399 That changes the way whether patterns happen. Lots of things 0:23:18.440 --> 0:23:21.240 that are all in play, and some of these are localized, 0:23:21.280 --> 0:23:25.240 and some can concern large portions like air movement. Oh yeah, yeah, 0:23:25.400 --> 0:23:29.240 some of them are are Some of the effects of 0:23:29.280 --> 0:23:32.399 these can be felt hundreds of miles from where the 0:23:32.560 --> 0:23:36.479 thing happened, right, which makes it even harder because you know, 0:23:36.720 --> 0:23:41.080 as a lady person, you sit there and think, all right, well, um, 0:23:41.160 --> 0:23:43.320 you know, because I can't see any clouds on the horizon, 0:23:43.400 --> 0:23:44.960 I think tonight is going to be all right. And 0:23:45.000 --> 0:23:48.080 then you could have a very fast moving system coming 0:23:48.119 --> 0:23:52.160