WEBVTT - TechStuff Classic:Weather Tech, Part 1 0:00:04.360 --> 0:00:12.319 Welcome to tech Stuff, a production from iHeartRadio. Hey there, 0:00:12.400 --> 0:00:15.720 and welcome to tech Stuff. I'm your host, Jonathan Strickland. 0:00:15.760 --> 0:00:18.880 I'm an executive producer with iHeartRadio. And how the tech 0:00:19.040 --> 0:00:23.200 are you? It is time for another classic episode of 0:00:23.440 --> 0:00:26.160 tech Stuff. This episode that you're about to hear originally 0:00:26.160 --> 0:00:32.839 published on April twentieth, twenty sixteen. Huh four twenty But no, 0:00:33.040 --> 0:00:37.760 this has nothing to do with anything you know, blazy. No, 0:00:37.920 --> 0:00:40.519 this has to do with weather technology. In fact, it's 0:00:40.560 --> 0:00:44.239 called Weather Tech Part one, and that tells you what 0:00:44.479 --> 0:00:47.760 next week's classic episode will be. So sit back and 0:00:47.920 --> 0:00:53.600 enjoy WeatherTech Part one from April twentieth, twenty sixteen. Today 0:00:53.840 --> 0:00:57.080 we're gonna talk about weather because of a listener request. 0:00:57.440 --> 0:01:02.360 This comes from Dress Sayan and dree I am so 0:01:02.400 --> 0:01:04.679 sorry if I mispronounced your name. I actually asked Dreese 0:01:04.920 --> 0:01:08.840 how to pronounce this name, and I can only hope 0:01:08.840 --> 0:01:12.240 I got close. But here's what Dreas had to say. Hey, 0:01:12.280 --> 0:01:15.640 I just wanted to ask Slash request something about the podcast. 0:01:15.840 --> 0:01:18.039 See a while back, I had a conversation with my dad. 0:01:18.240 --> 0:01:21.360 He commented how amazing it was these days. He can 0:01:21.400 --> 0:01:24.120 just check a website that will pretty accurately tell him 0:01:24.440 --> 0:01:27.000 whether it's going to rain in the next few hours. 0:01:27.120 --> 0:01:30.360 And where I said that, it doesn't seem like that's 0:01:30.600 --> 0:01:33.000 amazing progress to me. After all, when he was a 0:01:33.080 --> 0:01:35.920 kid in the sixties, they would report if it would 0:01:36.000 --> 0:01:38.680 rain the next day, and now it's just that we've 0:01:38.680 --> 0:01:40.680 got it down to a few hours instead of twenty 0:01:40.720 --> 0:01:43.040 four hours ahead. He laughed and said the weather report 0:01:43.080 --> 0:01:45.400 back then was pretty much a joke. Anyway, this gave 0:01:45.440 --> 0:01:46.840 me a lot to think about, and it seemed like 0:01:46.880 --> 0:01:49.440 something to learn about from the Tech Stuff podcast, because, 0:01:49.440 --> 0:01:51.400 to be honest, I have no clue how weather is 0:01:51.400 --> 0:01:55.640 accurately predicted. It's just always been there for me. So 0:01:55.680 --> 0:02:00.720 we're gonna talk about weather forecasting, meteorology, the technology used 0:02:00.720 --> 0:02:07.000 to make predictions, what those predictions actually mean. We're going 0:02:07.040 --> 0:02:10.320 to break all that down. There will probably be at 0:02:10.400 --> 0:02:14.639 least one or two references to how weather report. Weather 0:02:14.680 --> 0:02:19.400 reports are still largely the work of some estimations and 0:02:19.480 --> 0:02:23.519 best guesses, because, as it turns out, whether it's incredibly complicated, 0:02:23.880 --> 0:02:26.000 but hopefully by the end of it, you'll have a 0:02:26.040 --> 0:02:30.480 little bit more sympathy for meteorologists. Right right as opposed 0:02:30.480 --> 0:02:34.359 to my friend who in college wrote an essay explaining 0:02:34.880 --> 0:02:39.840 what level of hell meteorologists should inhabit based upon Dante's Inferno, 0:02:41.040 --> 0:02:44.000 which was kind of funny, but also I'm sure meteorologists 0:02:44.440 --> 0:02:47.760 find it less. So so let's start off with just 0:02:47.800 --> 0:02:53.680 talking about the history of predicting weather, and really you 0:02:53.720 --> 0:02:57.000 have to go all the way back to early human civilization, because, 0:02:57.000 --> 0:03:00.000 as it turns out, one of the most important factors 0:03:00.080 --> 0:03:02.040 that play a part in this is the fact that 0:03:02.080 --> 0:03:07.000 we humans are pretty good at recognizing patterns. Right, So 0:03:07.400 --> 0:03:09.920 when something happens over and over, we take note of it, 0:03:10.000 --> 0:03:12.200 and we start to look at the other things that 0:03:12.240 --> 0:03:15.040 are happening over and over, and then we start to 0:03:15.120 --> 0:03:19.560 draw some hypotheses. For example, we might think that one 0:03:19.680 --> 0:03:23.720 thing could cause the next thing, or we might think 0:03:24.000 --> 0:03:26.919 one thing simply indicates the next thing is going to happen. 0:03:27.800 --> 0:03:30.360 Here's a simple example. Let's say that you are a 0:03:30.440 --> 0:03:34.400 shepherd and you notice that the flock of sheep act 0:03:34.560 --> 0:03:38.160 in a certain odd way every time it's about to rain. 0:03:38.640 --> 0:03:41.200 You might either come to the conclusion that the sheep 0:03:41.240 --> 0:03:43.840 are able to sense the rain before it actually happens, 0:03:43.880 --> 0:03:46.280 and therefore that as an indicator that is going to rain, 0:03:46.960 --> 0:03:48.600 or you might come to the conclusion that, in fact, 0:03:48.640 --> 0:03:52.480 the sheep are causing it to rain. That's probably not true. 0:03:52.720 --> 0:03:55.960 There are two ways to take that. Yeah. Yeah, But eventually, 0:03:56.280 --> 0:03:59.280 through these observations you start to eliminate possibilities and you 0:03:59.320 --> 0:04:03.160 start to draw some conclusions. Now, in early human civilizations, 0:04:04.160 --> 0:04:08.480 we're talking about very broad conclusions, things like you notice 0:04:08.600 --> 0:04:12.600 that in general, the weather gets cooler as the year 0:04:12.720 --> 0:04:14.960 goes on. You might not even have a year at 0:04:14.960 --> 0:04:17.479 this point. You may just think, as time passes, the 0:04:17.520 --> 0:04:20.000 weather gets cooler until it gets really cold, and after 0:04:20.040 --> 0:04:22.440 it's really cold for a while, it starts to get 0:04:22.440 --> 0:04:24.560 warm again, and then it gets really warm, and then 0:04:24.560 --> 0:04:27.440 it gets hot, and then the whole cycle starts over. 0:04:27.680 --> 0:04:30.719 And you may also notice that the stars the way 0:04:30.760 --> 0:04:33.960 the stars are, you can tell that they are. It's 0:04:33.960 --> 0:04:37.599 a slightly different view as this time goes on, and 0:04:37.640 --> 0:04:40.440 you start to associate, oh, when the stars get into 0:04:40.480 --> 0:04:44.200 this slow you know, this kind of configuration, It means 0:04:44.200 --> 0:04:48.520 we're getting toward the time when we should really harvest food, 0:04:48.600 --> 0:04:51.360 because we're about to go into the winter months and 0:04:51.400 --> 0:04:54.440 otherwise we're going to lose everything we've been growing, or 0:04:54.760 --> 0:04:57.960 when it's this time we should start planting food because 0:04:57.960 --> 0:05:00.480 it's the best time for us to get a big yield. 0:05:00.640 --> 0:05:04.880 Later on climate, Yeah, and you start to figure out 0:05:04.920 --> 0:05:07.240 you build out a calendar based on this, and that 0:05:07.279 --> 0:05:10.480 calendar would be fairly rough, you know, wouldn't necessarily be 0:05:10.920 --> 0:05:13.400 reflective of an actual full year, but it would be 0:05:13.440 --> 0:05:17.040 more like an indicator of what you should be expecting 0:05:17.040 --> 0:05:21.000 in the next coming time. Right, So that's your basic 0:05:21.080 --> 0:05:24.680 like big picture stuff, using things like the way animals 0:05:24.720 --> 0:05:29.240 react or certain smells that you might detect before a rainstorm. 0:05:29.320 --> 0:05:32.880 That would be sort of the more acute weather type 0:05:32.920 --> 0:05:35.320 stuff as opposed to the seasonal type stuff. And you 0:05:35.360 --> 0:05:38.840 start to draw those conclusions too, and together you start 0:05:38.839 --> 0:05:43.560 building out general rules that tell you if this one 0:05:43.640 --> 0:05:46.360 thing is happening, then here's what you should expect. This 0:05:46.480 --> 0:05:51.400 sort of pattern recognition. And in fact, today some of 0:05:51.440 --> 0:05:56.359 our data still relies on that principle. It's just that 0:05:56.400 --> 0:05:59.599 we have way more information now at a much higher 0:05:59.600 --> 0:06:04.880 precision than ancient humans did. And speaking of that, I 0:06:04.920 --> 0:06:09.000 read that there are certain Aboriginal tribes that have been 0:06:09.480 --> 0:06:13.359 observing their weather patterns for over eighteen thousand generations, so 0:06:13.400 --> 0:06:15.440 that kind of gives you a sense of how far 0:06:15.480 --> 0:06:18.080 back this goes. Yeah, and and of course, you know, 0:06:18.120 --> 0:06:21.680 if you're talking about a very specific region, like a 0:06:21.880 --> 0:06:28.400 very relatively small geographic area, you could have a pretty 0:06:28.480 --> 0:06:32.000 accurate idea of what to expect based upon those sorts 0:06:32.000 --> 0:06:37.080 of observations. They might not be presented in the super cool, 0:06:37.240 --> 0:06:42.320 high tech way that modern meteorology tends to present it, 0:06:42.720 --> 0:06:46.200 but that doesn't make it any less valid necessarily. It 0:06:46.240 --> 0:06:48.719 may be a little more rough around the edges. But 0:06:48.760 --> 0:06:50.520 if you can still tell me that, hey, in three 0:06:50.600 --> 0:06:52.640 days we're going to get some rain, and three days 0:06:52.680 --> 0:06:57.480 later it rains, and you do that reliably, that's pretty impressive. Right. 0:06:58.160 --> 0:07:01.560 So if you want to start looking at people who 0:07:01.560 --> 0:07:05.680 were really thinking about whether in kind of almost a 0:07:05.720 --> 0:07:09.120 scientific sense, and one of the first people you would 0:07:09.120 --> 0:07:13.760 have to look at his Aristotle, big brain Aristotle. He 0:07:15.040 --> 0:07:21.200 was quite the thinker. He wrote about whether in Meteorologica, 0:07:21.280 --> 0:07:24.680 and he came up with a bunch of hypotheses, some 0:07:24.800 --> 0:07:28.280 column theories, I would say hypotheses, because none of these, 0:07:28.440 --> 0:07:30.520 not all of these proved true. They came up with 0:07:30.560 --> 0:07:33.200 some hypotheses about how stuff like rain and hail, and 0:07:33.280 --> 0:07:37.040 wind and clouds and thunder and lightning and hurricanes. What 0:07:37.280 --> 0:07:39.920 made them happen, how did they behave what were the 0:07:40.000 --> 0:07:43.440 rules that governed them? And some of his ideas were 0:07:43.560 --> 0:07:46.920 mostly right and some of his ideas were way off. 0:07:47.360 --> 0:07:51.960 But the problem was without ways to measure the various 0:07:52.000 --> 0:07:56.040 metrics associated with weather, it was kind of impossible to 0:07:56.080 --> 0:07:58.280 say one way or the other. So for about two 0:07:58.320 --> 0:08:02.000 thousand years, everyone kind of just went with it because 0:08:02.200 --> 0:08:05.960 you didn't have any way of proving or disproving any 0:08:06.000 --> 0:08:10.480 of the individual ideas. But you need a basis, Yeah, 0:08:10.480 --> 0:08:13.360 you know, at least it was something. It was at 0:08:13.440 --> 0:08:15.120 least something to work from. It was just it was 0:08:15.160 --> 0:08:18.720 just a question of time. When would people develop tools 0:08:19.160 --> 0:08:21.320 that would allow them to put these ideas to the 0:08:21.360 --> 0:08:25.400 test and either see which ones are mostly right but 0:08:25.480 --> 0:08:27.440 maybe need some tweaking, or in which ones you can 0:08:27.480 --> 0:08:31.040 just completely throw out the window, Which brings us up 0:08:31.120 --> 0:08:35.320 to the Renaissance, one of my favorite time periods. As 0:08:35.320 --> 0:08:38.240 it turns out, spend a lot of time there. Our 0:08:38.240 --> 0:08:42.800 listeners can't see. But right now Jonathan has a handlebar mustache, 0:08:43.000 --> 0:08:46.800 a giant handlebar mustache, because the character I play in 0:08:46.840 --> 0:08:51.760 the Georgia Renaissance Festival has such a mustache, and I 0:08:51.800 --> 0:08:55.079 will be performing as that character the day after we 0:08:55.120 --> 0:08:59.600 record this episode. It's opening weekend for the Georgia Renaissance Festival. 0:09:00.000 --> 0:09:03.280 Would you say that someone might have a handlebar mustache 0:09:03.320 --> 0:09:06.840 in the fifteenth century, around the time of German philosopher 0:09:07.040 --> 0:09:12.079 Nicholas of Cusa, It's quite possible. I mean, there's no 0:09:12.120 --> 0:09:15.280 reason they could not have one. It's not like there 0:09:15.320 --> 0:09:19.840 were social taboos about such things. Yeah. So this philosopher, 0:09:19.920 --> 0:09:23.320 Nicholas of Cusa, designed a device to measure the amount 0:09:23.320 --> 0:09:27.720 of moisture in the air, and we call these hygrometers. 0:09:28.240 --> 0:09:31.000 These are it's really kind of a way of measuring humidity, 0:09:31.520 --> 0:09:35.520 which here in Atlanta you can pretty much just says 0:09:35.800 --> 0:09:39.680 it's humid. It's so humid. Yeah, the humidity in Atlanta 0:09:39.920 --> 0:09:42.120 is brutal, to the point where I have friends who 0:09:42.200 --> 0:09:45.640 come in from Texas, where the temperatures in Texas can 0:09:45.640 --> 0:09:48.240 get twenty degrees hotter than it gets here in Atlanta. 0:09:48.320 --> 0:09:51.400 But because Texas has relatively low humidity through most of 0:09:51.400 --> 0:09:56.000 the state, they think the weather here is way worse, like, 0:09:56.200 --> 0:09:59.440 way more difficult to deal with, But how do you 0:09:59.480 --> 0:10:02.080 measure that? And he came up with an interesting idea. 0:10:02.160 --> 0:10:05.800 Now there's there's no indication that he ever built the 0:10:05.880 --> 0:10:08.400 device he came up with, but he said, what you 0:10:08.440 --> 0:10:11.240 do is you take a set of balanced scales, so 0:10:11.280 --> 0:10:12.600 you know what those look like. They have a little 0:10:12.640 --> 0:10:16.439 dish on either side, and on one side you put 0:10:16.480 --> 0:10:19.120 a large amount of wool, and on the other side 0:10:19.120 --> 0:10:23.600 you put some weights. He said stones. Other people later 0:10:23.640 --> 0:10:26.320 on said discs of wax didn't really matter. It just 0:10:26.360 --> 0:10:29.040 had to be a counterweight of some sort. Now, the 0:10:29.080 --> 0:10:33.040 purpose of the wool is to soak up moisture in 0:10:33.080 --> 0:10:36.520 the atmosphere, which would make the wool get heavier. This 0:10:36.559 --> 0:10:38.280 is what Nicholas was saying. Like, the wool will get 0:10:38.360 --> 0:10:42.000 heavier as it soaks up water from the air, and 0:10:42.080 --> 0:10:45.280 you'll be able to tell that because the scales will 0:10:45.320 --> 0:10:48.640 start to shift and you'll see that the side with 0:10:48.679 --> 0:10:51.880 the wool will start to get heavier. Then if it 0:10:51.960 --> 0:10:55.120 dries out, if the weather gets dry, the wool will 0:10:55.120 --> 0:10:58.520 start to lose moisture. It will evaporate, and you'll start 0:10:58.559 --> 0:11:00.520 to see that side of the scale moving up. It'll 0:11:00.559 --> 0:11:04.880 get lighter. Now, he never built that, But another big 0:11:04.960 --> 0:11:08.880 thinker of the Renaissance did get around to it, Leonardo 0:11:08.960 --> 0:11:13.880 da Vinci. Yes, he did everything. Yeah, when he wasn't 0:11:13.920 --> 0:11:18.760 building helicopters or designing tanks, which he never built, but 0:11:18.800 --> 0:11:20.920 he did design. He designed a tank, and he designed 0:11:20.960 --> 0:11:25.680 a really weird I think, gosh, it was something like 0:11:25.720 --> 0:11:29.720 a thirty three barrel gun, didn't he I think a 0:11:29.760 --> 0:11:34.040 diving suit as well. Pretty much any any sort of 0:11:34.640 --> 0:11:37.440 thing that in the Renaissance would sound like it's science fiction. 0:11:38.080 --> 0:11:40.040 She had some sort of hand in. He probably has 0:11:40.040 --> 0:11:44.200 a primitive tablet schematic somewhere. Yeah. Yeah, he probably at 0:11:44.240 --> 0:11:47.880 one point came out to his patrons and showed a 0:11:48.280 --> 0:11:51.480 wooden slate and talked about how if you ran your 0:11:51.480 --> 0:11:54.640 fingers across it you could you could paginate through. And 0:11:54.679 --> 0:11:57.320 then he'd say, I think you're gonna love it, and 0:11:57.520 --> 0:12:02.240 maybe even did a one more thing. So that was 0:12:02.280 --> 0:12:08.520 the first kind of weather related instrument that people were 0:12:08.559 --> 0:12:12.440 really thinking about. Another would come in the seventeenth century 0:12:12.720 --> 0:12:16.680 early sixteen hundreds, usually put around sixteen oh three, when 0:12:16.960 --> 0:12:21.000 physicist Galileo Galile created a thermoscope, which is sort of 0:12:21.000 --> 0:12:23.319 a predecessor to a thermometer. And it was a pretty 0:12:23.320 --> 0:12:25.600 simple idea. So you start with a container that has 0:12:25.600 --> 0:12:28.960 a small amount of liquid in it, usually water. That's 0:12:29.000 --> 0:12:32.880 your base. And then you also have a kind of 0:12:32.880 --> 0:12:36.680 a hollow tube of glass that ends in a bulb, 0:12:37.400 --> 0:12:40.920 so like a larger bulb at one end and open 0:12:41.000 --> 0:12:44.640 on the other end. And you could do something like 0:12:44.720 --> 0:12:47.280 warm the bulb if you want too, in your hands. 0:12:47.640 --> 0:12:50.120 But then you would put the bulb. You would put 0:12:50.120 --> 0:12:52.800 the tube into the small container of water. The bulb 0:12:52.840 --> 0:12:58.440 would be suspended above it. Usually the hollow straw like 0:12:58.679 --> 0:13:01.920 tube would be long enough, you know, several inches long. 0:13:02.280 --> 0:13:05.000 You could then observe that as the temperature of the 0:13:05.040 --> 0:13:08.200 bulb changed, the level of water in the tube would 0:13:08.240 --> 0:13:11.360 either go up or go down. And this is because 0:13:11.400 --> 0:13:15.120 the air inside the tube is either expanding or contracting, 0:13:15.160 --> 0:13:18.959 depending upon whether it's heating up or cooling down. And 0:13:19.360 --> 0:13:22.160 this wasn't a thermometer, but it was. It was interesting, 0:13:22.200 --> 0:13:26.080 and it was once again a start. Yeah. Later on 0:13:26.559 --> 0:13:31.000 someone looked at Galileo's little invention and said, what if 0:13:31.040 --> 0:13:34.600 we put like markings on the tube so you could 0:13:34.640 --> 0:13:38.400 say how many steps up or down the tube it went. 0:13:38.520 --> 0:13:41.959 Then we could even give indications of how much warmer 0:13:42.080 --> 0:13:45.440 or cooler. You could say it's four steps warmer or 0:13:45.480 --> 0:13:48.920 four steps cooler. That became the basis of the thermometer. 0:13:49.320 --> 0:13:52.320 So and that didn't take long. It was within about 0:13:52.400 --> 0:13:57.080 fifty years that you had the first working thermometers. Following 0:13:57.320 --> 0:14:01.000 this kind of proof of concept thermoscopy, there was also 0:14:01.160 --> 0:14:04.760 there is the Galilean thermometer. Are you familiar with these? 0:14:04.960 --> 0:14:08.880 I am not. You've probably seen one. They are the 0:14:09.000 --> 0:14:14.160 cylindrical glass They're usually very decorative for for like home 0:14:14.160 --> 0:14:17.319 office desk ers, and but these glass tubes, they are cylindrical. 0:14:17.520 --> 0:14:21.480 Typically inside they have these these little glass blown glass 0:14:21.600 --> 0:14:25.360 balls that contain their own liquid. Often it's a liquid 0:14:25.360 --> 0:14:28.000 that has dye in it, so they're blue or green 0:14:28.080 --> 0:14:30.360 or red or whatever. And each one has a little 0:14:30.400 --> 0:14:34.600 weight attached to it that has a temperature. And what 0:14:34.760 --> 0:14:39.960 happens is the balls represent different densities of water, and 0:14:40.040 --> 0:14:45.320 the temperature of the glass tube will change the density 0:14:45.520 --> 0:14:48.840 of the water inside the glass tube. And then you'll 0:14:48.880 --> 0:14:53.040 see whichever ball is at the bottommost of the tube 0:14:53.240 --> 0:14:57.200 the glass tube, as that represents the general temperature, and 0:14:57.240 --> 0:14:59.160 they tend to be between like you know, like about 0:14:59.160 --> 0:15:01.720 five degrees aparts, he might have sixty five degrees seventy 0:15:01.760 --> 0:15:04.760 seventy five degrees eighty that kind of thing. So whicheveryone's 0:15:04.800 --> 0:15:07.640 at the lowest point. That's the temperature of the water, 0:15:07.760 --> 0:15:12.120 thus the temperature of the area surrounding it. I tend 0:15:12.120 --> 0:15:14.000 to be used, like I said, as decorations for desks 0:15:14.000 --> 0:15:17.560 and stuff. Galileo actually did not invent that, but some 0:15:17.600 --> 0:15:19.880 of his students did. It was several of his students, 0:15:19.880 --> 0:15:24.280 so that's why it's called a Galilean Thermometer's neat. Yeah. Yeah, 0:15:24.320 --> 0:15:28.760 it's a very pretty way of seeing, generally speaking, what 0:15:28.840 --> 0:15:34.160 temperature the tube is and therefore probably what temperature the 0:15:34.240 --> 0:15:37.280 surrounding area is. Keeping in mind that water changes temperature 0:15:37.320 --> 0:15:41.360 more slowly than something like a room would, so it 0:15:41.400 --> 0:15:44.240 wouldn't be reflected immediately, but it's still kind of interesting. 0:15:45.000 --> 0:15:48.880 We'll be back with more about weather technology after this 0:15:48.960 --> 0:16:01.040 quick break. Then we have the This is a very 0:16:01.080 --> 0:16:06.080 important tool in predicting the weather. So barometer is all 0:16:06.080 --> 0:16:10.520 about predicting, or not predicting, but measuring atmospheric pressure. So 0:16:11.200 --> 0:16:14.320 first thing, just in case you weren't aware, the atmosphere 0:16:14.560 --> 0:16:18.200 exerts pressure on us. It pushes down. Gravity is technically 0:16:18.200 --> 0:16:21.960 pulling down on the atmosphere. So the lower you are 0:16:22.840 --> 0:16:24.960 to the surface of the air, like the closer the 0:16:24.960 --> 0:16:28.640 lower down and elevation you are, the more pressure you 0:16:28.680 --> 0:16:31.760 feel from atmosphere. This is why as you climb a 0:16:31.800 --> 0:16:36.280 mountain or you get on a plane, you experience lower 0:16:36.280 --> 0:16:38.360 amounts of air pressure. It's also why you have to 0:16:38.400 --> 0:16:41.880 pressurize aircraft that fly it pretty high altitudes, otherwise you 0:16:41.880 --> 0:16:47.040 would suffer some pretty rough effects. And on the Earth's 0:16:47.040 --> 0:16:51.320 surface the force of gravity. Due to the force of gravity, 0:16:51.360 --> 0:16:55.480 the pressure is about fourteen point seven pounds per square inch. Yeah, 0:16:55.560 --> 0:16:57.440 that's a sea level. Yeah, that's what we call an 0:16:57.440 --> 0:17:01.160 atmosphere of pressure. Right one atmosphere pressure, you look at 0:17:01.200 --> 0:17:03.760 it at sea level. Specifically, you're looking at it at 0:17:03.840 --> 0:17:06.760 sea level at fifty nine degrees fahrenheit, which is fifteen 0:17:06.760 --> 0:17:10.400 degrees celsius. You have to be very specific because temperature 0:17:10.400 --> 0:17:15.200 will change pressures as you warm up air. Typically this 0:17:15.280 --> 0:17:17.879 is just a general rule of thumb. When something warms up, 0:17:18.560 --> 0:17:23.680 that means molecules are moving. That's the energy of motion. Ultimately, 0:17:23.680 --> 0:17:26.520 you're making these molecules move faster and that's kind of 0:17:26.920 --> 0:17:31.760 what heat looks like. So as molecules of air move 0:17:32.040 --> 0:17:35.879 around more, they spread out more, it becomes less dense. 0:17:36.359 --> 0:17:39.160 So that would change the atmospheric pressure as well. That's 0:17:39.160 --> 0:17:41.600 why you have to take temperature into account. When you 0:17:41.640 --> 0:17:45.719 talk about one atmosphere of pressure. That's very specific. It's 0:17:45.760 --> 0:17:51.119 at sea level at that temperature, that's one atmosphere. So 0:17:51.280 --> 0:17:53.800 that's that's kind of interesting anyway. The first person to 0:17:53.880 --> 0:17:56.639 actually create a barometer was a guy by the name 0:17:56.680 --> 0:18:02.359 of Evangelista Torricelli, and his first invention people just called 0:18:02.440 --> 0:18:07.560 Toricelli's tube, which doesn't seem very dignified. No, it needs 0:18:07.560 --> 0:18:10.600 a special name. Yeah, but Tori Chelli's tube, it wasn't 0:18:10.680 --> 0:18:12.800 quite the barometer yet. What he was doing was he 0:18:12.840 --> 0:18:17.000 was actually experimenting with the concept of vacuums, like creating 0:18:17.000 --> 0:18:22.000 a vacuum within a tube or some other container. He 0:18:22.080 --> 0:18:23.520 was just it was one of those things where we 0:18:23.560 --> 0:18:27.560 didn't fully understand what that was, how it worked, and 0:18:27.600 --> 0:18:30.160 so he did this experiment. He was actually friends with Galileo, 0:18:30.359 --> 0:18:34.760 and Galileo said, hey, Evangelista, I got an idea for you. 0:18:34.840 --> 0:18:36.600 Why don't you take one of those tubes you've been 0:18:36.640 --> 0:18:40.320 working with, and fill it with mercury and use that 0:18:40.400 --> 0:18:42.359 in your vacuum experiments. Will be a lot easier to 0:18:42.440 --> 0:18:45.159 see than some other liquid. And Tori Chelli says, all right, 0:18:45.160 --> 0:18:47.040 I'll give it a shot. So he took a four 0:18:47.080 --> 0:18:49.760 foot long glass tube and he filled the glass tube 0:18:49.800 --> 0:18:51.720 with mercury so it was closed on one end, open 0:18:51.760 --> 0:18:54.480 on the other, and then he inverted the tube into 0:18:54.520 --> 0:18:57.159 a dish, and the dish had a little bit of 0:18:57.240 --> 0:18:59.160 mercury at the bottom of it. And it showed that 0:18:59.640 --> 0:19:02.480 this the fact that the top of the tube, you know, 0:19:02.600 --> 0:19:04.400 like the mercury went all the way up this four 0:19:04.440 --> 0:19:07.960 foot tube. The liquid didn't just come rushing out and 0:19:08.080 --> 0:19:11.359 spill everywhere, right, because the vacuum is what held it 0:19:11.400 --> 0:19:15.359 in place. And he says, look, see, I was so smart. 0:19:15.400 --> 0:19:18.840 This shows that there's something working here. We're gonna really 0:19:18.880 --> 0:19:21.480 explore this. But then he noticed something else that was 0:19:21.560 --> 0:19:24.040 really interesting. He noticed that despite the fact that the 0:19:24.080 --> 0:19:27.960 tube could stay upright and the liquid would stay in 0:19:28.000 --> 0:19:31.240 there from day to day, there were variations and how 0:19:31.359 --> 0:19:33.760 high the mercury would be in the tube. And it 0:19:33.800 --> 0:19:36.120 wasn't just sinking down. It's not like it was leaking 0:19:36.880 --> 0:19:38.800 over the course of a week. So like you come 0:19:38.840 --> 0:19:40.359 back and it's a couple inches lower, and then the 0:19:40.400 --> 0:19:42.240 next day it's a couple inches lower. It wasn't like that. 0:19:42.320 --> 0:19:45.400 Some days it was actually higher. And he started thinking, well, 0:19:45.400 --> 0:19:48.840 what the heck would cause the mercury to go up 0:19:48.920 --> 0:19:53.040 or down this tube? The atmosphere that's it. The atmospheric 0:19:53.119 --> 0:19:56.720 pressure pressing down on the liquid in the dish. That's 0:19:56.760 --> 0:20:00.600 what determined whether the well, that's what to the height 0:20:00.720 --> 0:20:03.359 of the mercury inside the tube. So on days with 0:20:03.560 --> 0:20:08.280 higher atmospheric pressure, it pushes down on that exposed liquid 0:20:08.320 --> 0:20:11.119 within the dish and it forces that liquid to go 0:20:11.359 --> 0:20:15.000 up the tube, and so the height of the liquid 0:20:15.000 --> 0:20:18.240 inside the tube goes up. On days where atmospheric pressure 0:20:18.280 --> 0:20:21.720 is lower, some of that liquid comes down and starts 0:20:21.720 --> 0:20:25.640 filling up the dish until it reaches that kind of equilibrium. 0:20:25.960 --> 0:20:28.719 And then he's so he said, hey, this shows that 0:20:28.760 --> 0:20:32.600 the atmosphere itself exerts pressure. And not only that, but 0:20:32.640 --> 0:20:36.919 the pressure is not consistent day to day. It can change. 0:20:37.440 --> 0:20:41.520 And in sixteen forty four Torchelli built the first mercury barometer. 0:20:41.600 --> 0:20:44.680 So now he was building something specifically to measure this thing, 0:20:45.080 --> 0:20:48.879 because before he was really demonstrating the concept of vacuums. 0:20:49.880 --> 0:20:53.160 So now we've got the barometer, we've got the thermometer, 0:20:53.240 --> 0:20:56.560 we've got the hygrometer, essential things. Yeah, these are the 0:20:56.600 --> 0:21:02.280 basics for taking measurements about weather. And at that point 0:21:02.960 --> 0:21:08.280 it was really the start of gathering enough information so 0:21:08.280 --> 0:21:12.080 that meteorology, the science of meteorology, could actually exist, right 0:21:12.119 --> 0:21:15.880 because now we could not just observe patterns, we could 0:21:15.880 --> 0:21:20.960 actually quantify what was happening. And by quantifying it, we 0:21:21.000 --> 0:21:22.960 could get to this level of precision where we could 0:21:23.000 --> 0:21:29.879 start to draw more specific conclusions as to what would 0:21:29.920 --> 0:21:34.560 or would not happen based upon current conditions. So, all 0:21:34.600 --> 0:21:38.240 that being said, we still have some issues predicting weather. 0:21:38.320 --> 0:21:42.280 So why is that? Well, like I said before, it's complicated. 0:21:43.480 --> 0:21:48.600 So here's the thing. Our atmosphere is fluid. It's a gas, 0:21:48.880 --> 0:21:53.959 but it behaves via fluid dynamics. Dylan, have you ever 0:21:54.000 --> 0:21:57.600 studied fluid dynamics, I don't believe. So I studied them 0:21:57.600 --> 0:22:02.440 in physics and they are rutally difficult to comprehend because 0:22:02.480 --> 0:22:06.520 it can get so there's so many factors that can 0:22:06.680 --> 0:22:10.560 affect a fluid, so and the Earth has a whole 0:22:10.600 --> 0:22:13.600 bunch of them happening at once. Right. First of all, 0:22:13.640 --> 0:22:19.359 there's this big ball of plasma that's about eight and 0:22:19.400 --> 0:22:26.040 a half light minutes away from us. It's called the Sun. Yeah, 0:22:26.119 --> 0:22:28.040 you know, on nice days you might even get a 0:22:28.040 --> 0:22:31.840 glimpse of it. So the Sun provides obviously a ton 0:22:31.920 --> 0:22:35.280 of energy to the Earth and so we So the 0:22:35.320 --> 0:22:38.320 Earth absorbs a lot of solar radiation and that can 0:22:38.359 --> 0:22:40.600 affect fluid dynamics because you've got a lot of heat 0:22:40.680 --> 0:22:44.080 coming into a system. On top of that, you've got 0:22:44.119 --> 0:22:47.640 the Earth. Earth's not standing still, the Earth is rotating. 0:22:47.920 --> 0:22:54.199 That rotational force creates other fluidic effects in the atmosphere. 0:22:54.359 --> 0:22:56.440 We'll talk about those specifically when we get to high 0:22:56.480 --> 0:23:01.639 and low pressure systems. You've got gravity, which is pulling 0:23:01.760 --> 0:23:05.960 down on the fluid, so that's another force that's in play. 0:23:06.080 --> 0:23:09.080 You've got differences in surface temperature on the Earth, so 0:23:09.119 --> 0:23:11.840 you've got areas where it's very cold versus areas that 0:23:11.840 --> 0:23:15.480 are very hot. That in turn affects the atmosphere and 0:23:15.600 --> 0:23:19.359 can change things around. You have air currents a big 0:23:19.400 --> 0:23:21.919 deal there. That's also partially due to the rotation of 0:23:21.960 --> 0:23:24.600 the Earth. You've got mountain ranges which can act as 0:23:24.640 --> 0:23:27.160 like a windbreaker for certain things that changes the way 0:23:27.200 --> 0:23:31.200 weather patterns happen. Lots of things that are all in play, 0:23:31.320 --> 0:23:33.879 and some of these are localized, and some can concern 0:23:34.000 --> 0:23:37.280 large portions like air movement. Oh yeah, yeah, some of 0:23:37.280 --> 0:23:41.520 them are. Some of the effects of these can be 0:23:41.600 --> 0:23:45.680 felt hundreds of miles from where the thing happened, right, 0:23:46.000 --> 0:23:49.280 which makes it even harder because as a lady person, 0:23:49.640 --> 0:23:52.959 you sit there and think, all right, well, you know, 0:23:53.119 --> 0:23:55.000 because I can't see any clouds on the horizon, I 0:23:55.040 --> 0:23:57.040 think tonight's going to be all right, And then you 0:23:57.040 --> 0:24:00.680 could have a very fast moving system coming in due 0:24:00.720 --> 0:24:05.120 to something that happens well out of sight. It ends 0:24:05.200 --> 0:24:07.760 up creating a lot of things that could be counterintuitive, 0:24:07.840 --> 0:24:11.760 depending upon what you have at your disposal. Like, of course, 0:24:11.800 --> 0:24:14.239 the more information you have, the better conclusions you can 0:24:14.320 --> 0:24:17.040 draw in general, assuming that you also know what you're 0:24:17.080 --> 0:24:22.399