1 00:00:04,120 --> 00:00:07,160 Speaker 1: Get in touch with technology with tech Stuff from how 2 00:00:07,200 --> 00:00:13,680 Speaker 1: stuff works dot com. Hey there, and welcome to tech Stuff. 3 00:00:13,720 --> 00:00:16,599 Speaker 1: I'm your host, Jonathan Strickland. I'm an executive producer with 4 00:00:16,640 --> 00:00:19,040 Speaker 1: how Stuff Works in love all things tech, and it's 5 00:00:19,079 --> 00:00:23,439 Speaker 1: time for another classic episode of tech Stuff. This one 6 00:00:23,960 --> 00:00:30,880 Speaker 1: published Holy cal September twenty nine, two thousand and ten. Wow, 7 00:00:30,920 --> 00:00:33,440 Speaker 1: this one's really diving into the archives, and I do 8 00:00:33,520 --> 00:00:37,400 Speaker 1: mean diving because this episode is all about how sonar works. 9 00:00:38,159 --> 00:00:42,440 Speaker 1: Dive dive boop boop boop. So I talked a lot 10 00:00:42,440 --> 00:00:46,320 Speaker 1: about echolocation in recent episodes, this is the episode where 11 00:00:46,400 --> 00:00:50,320 Speaker 1: we really looked at the tech behind sonar. So listen 12 00:00:50,440 --> 00:00:55,640 Speaker 1: as Chris and I explore the incredible world of sonar. 13 00:00:55,680 --> 00:00:58,400 Speaker 1: I hope you enjoy. Have I got this straight? Jonesy, 14 00:00:58,720 --> 00:01:01,840 Speaker 1: A forty million dollar computer tells you you're chasing an earthquake, 15 00:01:01,880 --> 00:01:04,120 Speaker 1: but you don't believe, and you come up with this 16 00:01:04,280 --> 00:01:09,320 Speaker 1: on your own that had a direct bearing to our 17 00:01:09,360 --> 00:01:14,399 Speaker 1: topic today, and that topic would be sonar, sound navigation 18 00:01:14,600 --> 00:01:19,680 Speaker 1: and ranging. Well, that pretty much covers it, so well, 19 00:01:19,760 --> 00:01:21,560 Speaker 1: that's exactly what it is. It's one of those nice, 20 00:01:22,640 --> 00:01:24,679 Speaker 1: nice words that sort of covers it. So yeah, no, 21 00:01:24,720 --> 00:01:27,600 Speaker 1: it's it's it's very it's very much exactly what sounds like. 22 00:01:27,640 --> 00:01:32,080 Speaker 1: It's using sound to navigate and to to find the 23 00:01:32,200 --> 00:01:35,120 Speaker 1: distance from other objects. As it turns out, there a 24 00:01:35,160 --> 00:01:37,959 Speaker 1: lot of ways to use sonar um and we'll get 25 00:01:38,000 --> 00:01:40,320 Speaker 1: into that in a minute, but there are also a 26 00:01:40,360 --> 00:01:44,360 Speaker 1: lot of different types of applications, uh, different ways to 27 00:01:44,640 --> 00:01:48,360 Speaker 1: use it as in like um, different kinds of equipment 28 00:01:48,640 --> 00:01:52,080 Speaker 1: that that can be used to find depth and identify 29 00:01:52,160 --> 00:01:55,360 Speaker 1: things in the water and even map the cea floor 30 00:01:55,400 --> 00:01:57,520 Speaker 1: if you want to do that. Ye, and uh, actually 31 00:01:57,600 --> 00:01:59,800 Speaker 1: the you know, we're not the only ones to to 32 00:02:00,120 --> 00:02:03,080 Speaker 1: use sonar, not by a long shot. True. Dolphins and 33 00:02:03,080 --> 00:02:05,880 Speaker 1: whales use it to other animals. Yes, that would be 34 00:02:05,880 --> 00:02:09,920 Speaker 1: an echolocation, Yes, yeah, exactly, that's what the sonars based 35 00:02:09,919 --> 00:02:12,799 Speaker 1: off of. It's the idea of the way sound travels. 36 00:02:12,919 --> 00:02:15,200 Speaker 1: And so if you sound travels and waves, it's a 37 00:02:15,280 --> 00:02:18,680 Speaker 1: it's actually a physical uh thing. It's you know, we 38 00:02:18,720 --> 00:02:21,840 Speaker 1: don't see it, but it is a physical effect. When 39 00:02:22,040 --> 00:02:26,000 Speaker 1: you make a sound, you are causing stuff to bang 40 00:02:26,080 --> 00:02:31,359 Speaker 1: against each other. That sounds so so scientific. It's though, 41 00:02:32,040 --> 00:02:35,160 Speaker 1: so when sound travels, it's really lots of air molecules 42 00:02:35,160 --> 00:02:39,400 Speaker 1: bouncing against each other until well really just until it disperses, 43 00:02:39,680 --> 00:02:42,960 Speaker 1: so it keeps on going. I mean, and we detect sound, 44 00:02:42,960 --> 00:02:45,800 Speaker 1: of course through hearing, but there are other ways to 45 00:02:45,960 --> 00:02:48,480 Speaker 1: detect it. There there are sounds that are outside of 46 00:02:48,600 --> 00:02:52,000 Speaker 1: our range of hearing that we can sense. Like there's 47 00:02:52,040 --> 00:02:53,840 Speaker 1: some that are so low that you know, you can't 48 00:02:53,880 --> 00:02:56,680 Speaker 1: hear it, but you can feel it. That's scrumbing feeling 49 00:02:57,040 --> 00:03:02,760 Speaker 1: from from from and when sound hits a really solid object, 50 00:03:03,600 --> 00:03:06,120 Speaker 1: it bounces it, it refracts off as some of it 51 00:03:06,160 --> 00:03:09,640 Speaker 1: reflects back and uh, and that's where we get the 52 00:03:09,639 --> 00:03:13,359 Speaker 1: whole echo effect. So when you're in the right kind 53 00:03:13,400 --> 00:03:16,160 Speaker 1: of environment and you speak and you hear that echo, 54 00:03:16,320 --> 00:03:19,560 Speaker 1: that's those sound waves bouncing back and coming back to you. Well, 55 00:03:19,720 --> 00:03:25,040 Speaker 1: you can use this to find your way around an environment, right, Well, um, 56 00:03:25,200 --> 00:03:28,000 Speaker 1: so where does sonar come from? Then we have to 57 00:03:28,040 --> 00:03:32,200 Speaker 1: figure out exactly. Uh, really when that all started taking place, 58 00:03:32,280 --> 00:03:35,520 Speaker 1: and I think it was really probably, I mean, people 59 00:03:35,520 --> 00:03:38,200 Speaker 1: have been doing it for a long time. Yeah, you could, 60 00:03:38,200 --> 00:03:41,120 Speaker 1: you could identify things and under the surface of the water. 61 00:03:41,280 --> 00:03:43,920 Speaker 1: But why are you creating him? Because my favorite man 62 00:03:43,960 --> 00:03:47,120 Speaker 1: of all time did some experiments with listening to sound 63 00:03:47,120 --> 00:03:53,200 Speaker 1: through water. Okay, Leonardo da Vinci, we just finished talking 64 00:03:53,200 --> 00:03:55,720 Speaker 1: about him a second ago, which I'll try and make 65 00:03:55,760 --> 00:03:58,440 Speaker 1: sure that the podcast publish in the right order. But no, 66 00:03:58,640 --> 00:04:03,920 Speaker 1: Leonardo da Vinci back in experimented with with listening to 67 00:04:04,320 --> 00:04:07,640 Speaker 1: sounds through water. He would insert a tube into into 68 00:04:07,640 --> 00:04:11,160 Speaker 1: water and put his ear to the tube like straw. Yeah, 69 00:04:11,480 --> 00:04:14,240 Speaker 1: pretty much like a straw. Larger than a straw, Mr 70 00:04:14,280 --> 00:04:17,240 Speaker 1: da Vinci. Why are you listening to your drink if 71 00:04:17,240 --> 00:04:20,800 Speaker 1: you had a drinking problem? So, but yeah, he would 72 00:04:20,839 --> 00:04:23,240 Speaker 1: use this to to kind of listen to uh to 73 00:04:23,360 --> 00:04:26,640 Speaker 1: the two noises, with the idea that if you could 74 00:04:26,760 --> 00:04:29,400 Speaker 1: create the right system, you would be able to detect 75 00:04:29,480 --> 00:04:33,000 Speaker 1: when things were approaching through the water. Now, during da 76 00:04:33,040 --> 00:04:35,880 Speaker 1: Vinci's time, this wasn't really that big a problem. Things 77 00:04:35,960 --> 00:04:38,400 Speaker 1: usually approached on the water, and if they were in 78 00:04:38,440 --> 00:04:41,159 Speaker 1: the water, they weren't really something you needed to worry about. 79 00:04:42,480 --> 00:04:46,800 Speaker 1: The frogman of his day not not so effective, but 80 00:04:47,560 --> 00:04:50,280 Speaker 1: getting all the way up to the eighteen or the 81 00:04:50,360 --> 00:04:55,239 Speaker 1: nineteenth century, rather they hundreds uh you started to some 82 00:04:55,240 --> 00:04:59,960 Speaker 1: some lighthouses would have underwater bells that would be uh 83 00:05:00,240 --> 00:05:05,000 Speaker 1: placed around the area to warn ships of of hazards, 84 00:05:05,080 --> 00:05:07,960 Speaker 1: so ships could actually listen as they approached land and 85 00:05:08,040 --> 00:05:09,880 Speaker 1: they heard bells, they knew they were coming up on 86 00:05:10,000 --> 00:05:12,960 Speaker 1: shoals and they could they could alter their course before 87 00:05:13,120 --> 00:05:19,280 Speaker 1: running aground. And then uh in around nineteen sixteen. Uh 88 00:05:19,800 --> 00:05:21,960 Speaker 1: it was an early passive so in our system. Will 89 00:05:21,960 --> 00:05:24,880 Speaker 1: explain what that means UH in a minute. But they 90 00:05:24,880 --> 00:05:28,279 Speaker 1: were using strings of microphones towed by ships, which is 91 00:05:28,560 --> 00:05:31,320 Speaker 1: again something that dates up to the present in a 92 00:05:31,320 --> 00:05:35,920 Speaker 1: different form. But by um and of course thinking back 93 00:05:35,960 --> 00:05:38,680 Speaker 1: on it, that's you know World War one, right, the 94 00:05:38,720 --> 00:05:42,040 Speaker 1: British and American scientists had developed an active so in 95 00:05:42,120 --> 00:05:44,600 Speaker 1: our system, UM, you know that that was a big 96 00:05:44,600 --> 00:05:47,840 Speaker 1: concern at the time because of course the German uh 97 00:05:48,200 --> 00:05:52,160 Speaker 1: U boats were patrolling and it was some scary stuff. Yeah, 98 00:05:52,240 --> 00:05:55,640 Speaker 1: actually it was. It was a very intimidating weapon, definitely. 99 00:05:55,640 --> 00:05:57,240 Speaker 1: I mean there had been something sorry I keep coming, 100 00:05:57,880 --> 00:06:01,000 Speaker 1: there had been submarines before that, but sure, the German 101 00:06:01,040 --> 00:06:03,440 Speaker 1: U boats in World War One were a very effective 102 00:06:03,440 --> 00:06:08,640 Speaker 1: way of taking control of the Atlantic Ocean and the 103 00:06:08,640 --> 00:06:11,480 Speaker 1: shipping back and forth between the continents. So it's sonar 104 00:06:11,640 --> 00:06:14,200 Speaker 1: was something that they were very rapidly trying to work 105 00:06:14,200 --> 00:06:17,680 Speaker 1: out exactly. And it's funny because well, not funny, but 106 00:06:17,760 --> 00:06:20,640 Speaker 1: it's it's interesting to me that really the the event 107 00:06:20,839 --> 00:06:24,000 Speaker 1: that kind of started all this off wasn't World War One, 108 00:06:24,040 --> 00:06:27,640 Speaker 1: because by then they were pretty far into it, but 109 00:06:27,640 --> 00:06:30,559 Speaker 1: they did have an interest, yes, yes, to talk about 110 00:06:30,720 --> 00:06:33,039 Speaker 1: To talk about how this really started off, you really 111 00:06:33,040 --> 00:06:34,960 Speaker 1: got to look back to a certain event that happened 112 00:06:35,000 --> 00:06:37,920 Speaker 1: in nineteen twelve. Oh really, and what was that event? Well, 113 00:06:37,960 --> 00:06:40,839 Speaker 1: there was a little boat that happened to sink. Oh yes, 114 00:06:41,000 --> 00:06:45,240 Speaker 1: that little boat. Yeah, yeah, don't they go um, my 115 00:06:45,320 --> 00:06:49,400 Speaker 1: heart will go onto Yeah, the Titanic disaster, Titang disaster. 116 00:06:50,720 --> 00:06:53,640 Speaker 1: Following that, that's when we saw the first patent for 117 00:06:53,880 --> 00:06:57,719 Speaker 1: underwater echo ranging demands. So that was that was where 118 00:06:58,400 --> 00:07:01,160 Speaker 1: the first patent was filed UM and it was filed 119 00:07:01,240 --> 00:07:03,800 Speaker 1: at the British Patent Office by Lewis Richardson, who was 120 00:07:03,800 --> 00:07:07,359 Speaker 1: a meteorologist UM and he he had come up with 121 00:07:07,400 --> 00:07:11,760 Speaker 1: this idea of creating a way to locate objects underwater 122 00:07:12,120 --> 00:07:15,600 Speaker 1: using sound. You would you would fire sound out, you 123 00:07:15,600 --> 00:07:18,600 Speaker 1: would measure the sound that comes back, and through that 124 00:07:18,680 --> 00:07:22,520 Speaker 1: you would figure out what was there, how far away 125 00:07:22,520 --> 00:07:25,160 Speaker 1: it was, whether it was moving or not. I mean, 126 00:07:25,160 --> 00:07:27,840 Speaker 1: these were all the concepts now back in nineteen twelve, 127 00:07:27,840 --> 00:07:30,840 Speaker 1: they didn't really have a way of achieving this. He 128 00:07:30,840 --> 00:07:34,280 Speaker 1: he panted the idea, but it wasn't until, like Chris said, 129 00:07:34,280 --> 00:07:38,680 Speaker 1: around nineteen eighteen that we started to really see accelerated development, 130 00:07:38,760 --> 00:07:41,520 Speaker 1: because then you had a wartime use for it, and 131 00:07:41,640 --> 00:07:43,880 Speaker 1: it was really important to find a way to to 132 00:07:44,000 --> 00:07:48,320 Speaker 1: detect those submarines, those U boats. Yeah, icebergs were were 133 00:07:48,360 --> 00:07:51,600 Speaker 1: obviously concerned, especially in the North Sea and various like that. 134 00:07:51,880 --> 00:07:56,080 Speaker 1: Um because you know, as as is in the case 135 00:07:56,080 --> 00:07:58,480 Speaker 1: of many cliches, there is an element of truth in it. 136 00:07:58,600 --> 00:08:00,680 Speaker 1: The tip of the iceberg really is, you know, the 137 00:08:00,720 --> 00:08:03,760 Speaker 1: smallest right part, and so much of it is underwater, 138 00:08:03,840 --> 00:08:06,200 Speaker 1: and you can't tell without some kind of device. And 139 00:08:06,240 --> 00:08:09,640 Speaker 1: I think that's uh. The earliest, earliest sonar or the 140 00:08:09,640 --> 00:08:15,040 Speaker 1: earliest echolocation devices were not very precise. In fact, they 141 00:08:15,040 --> 00:08:16,880 Speaker 1: were so imprecise that they could tell you that there 142 00:08:16,920 --> 00:08:19,400 Speaker 1: was an iceberg, but could not tell you where the 143 00:08:19,480 --> 00:08:22,280 Speaker 1: iceberg was, So you you might know that there's an 144 00:08:22,320 --> 00:08:25,080 Speaker 1: iceberg somewhere within a two mile radius of your ship, 145 00:08:25,240 --> 00:08:27,960 Speaker 1: which is not entirely helpful, although I guess It tells 146 00:08:28,000 --> 00:08:30,400 Speaker 1: you to keep an eye out so that you you 147 00:08:30,440 --> 00:08:32,520 Speaker 1: don't see it just before you hit it, you know, 148 00:08:32,559 --> 00:08:35,440 Speaker 1: you you know, to keep an eye out for for 149 00:08:35,520 --> 00:08:40,160 Speaker 1: icebergs um. By the by the time World War two 150 00:08:40,200 --> 00:08:45,000 Speaker 1: came around, that's when the because early sonar was really 151 00:08:45,080 --> 00:08:48,680 Speaker 1: led by the British, they made the biggest advances in 152 00:08:48,760 --> 00:08:51,320 Speaker 1: sonar technology. They didn't call it sonar. They called it 153 00:08:51,400 --> 00:08:55,719 Speaker 1: as dick A S D I c UH and UH. 154 00:08:56,080 --> 00:08:58,640 Speaker 1: The A S D was actually a code. It was 155 00:08:58,679 --> 00:09:01,959 Speaker 1: It was so that the people outside of the top 156 00:09:02,040 --> 00:09:05,840 Speaker 1: secret development wouldn't know what the scientists were working on. 157 00:09:06,440 --> 00:09:08,719 Speaker 1: So people say, well, what does as DICK stand for? Well, 158 00:09:08,720 --> 00:09:11,160 Speaker 1: it kind of stands for keep your nose out of 159 00:09:11,200 --> 00:09:14,400 Speaker 1: it MR. So it wasn't really until World War two 160 00:09:14,400 --> 00:09:18,079 Speaker 1: that the United States actually outpaced the British in this 161 00:09:18,160 --> 00:09:22,040 Speaker 1: technology and uh, and that's when, you know, the term 162 00:09:22,160 --> 00:09:25,640 Speaker 1: sonar started to pop up, and that eventually became the 163 00:09:25,679 --> 00:09:29,240 Speaker 1: de facto term for the technology. Right right now, we 164 00:09:29,280 --> 00:09:32,920 Speaker 1: should probably at this point go into the two basic, 165 00:09:33,600 --> 00:09:37,040 Speaker 1: very very very basic types of sonar, so active and passive. 166 00:09:37,120 --> 00:09:40,000 Speaker 1: Active and passive, and I think passive is the easiest 167 00:09:40,040 --> 00:09:44,240 Speaker 1: one to explain yes, Basically you're receiving the sounds of 168 00:09:44,360 --> 00:09:47,840 Speaker 1: the water around you. You're listening, yes, so simply listening. 169 00:09:47,920 --> 00:09:52,040 Speaker 1: So passive passive sonar is where you have some sort 170 00:09:52,080 --> 00:09:55,720 Speaker 1: of sound collection device, usually a hydrophone, which is just 171 00:09:56,000 --> 00:09:58,000 Speaker 1: a microphone that you can use in the water. Right, 172 00:09:58,480 --> 00:10:01,520 Speaker 1: you would have hydrophones play and you may have a 173 00:10:01,520 --> 00:10:05,480 Speaker 1: couple of different passive sonar stations so that you have 174 00:10:05,600 --> 00:10:09,720 Speaker 1: hydrogen phones directed in specific areas, so that way you 175 00:10:09,720 --> 00:10:12,040 Speaker 1: can tell where the sound is coming from, not just 176 00:10:12,160 --> 00:10:17,080 Speaker 1: that there is sound, and you listen carefully for any 177 00:10:17,160 --> 00:10:21,160 Speaker 1: kind of indication of other activity in the water. And 178 00:10:21,880 --> 00:10:25,360 Speaker 1: it's interesting because as I was doing my research, I 179 00:10:25,440 --> 00:10:30,280 Speaker 1: discovered that that if you were a trained sonar operator, yes, 180 00:10:30,720 --> 00:10:33,720 Speaker 1: and you heard a submarine. Let's say you're in a 181 00:10:33,720 --> 00:10:37,320 Speaker 1: submarine and you heard another submarine, right, you could actually 182 00:10:37,360 --> 00:10:41,480 Speaker 1: identify where that submarine what was from, based upon the 183 00:10:41,480 --> 00:10:45,160 Speaker 1: sound you heard. Yes, that is correct, it is That 184 00:10:45,320 --> 00:10:48,320 Speaker 1: is to me as phenomenal. Well, every uh, as I 185 00:10:48,400 --> 00:10:52,880 Speaker 1: understand it, every ship of any kind, submarine or ship 186 00:10:53,000 --> 00:10:55,440 Speaker 1: or you know, I guess boat depending on what's on 187 00:10:55,480 --> 00:10:59,600 Speaker 1: the boat, has its own audio signature. Could be the engines, 188 00:11:00,360 --> 00:11:03,480 Speaker 1: um or basically anything that's going on if they are 189 00:11:03,520 --> 00:11:06,360 Speaker 1: electronics on board did make a noise if you know, 190 00:11:06,440 --> 00:11:11,760 Speaker 1: fans things like that. Some those things can help identify, um, 191 00:11:11,800 --> 00:11:15,920 Speaker 1: another vessel in the water to the listening vessel. Yeah. 192 00:11:15,960 --> 00:11:18,600 Speaker 1: For example, in the United States, most of the submarines 193 00:11:18,640 --> 00:11:22,760 Speaker 1: were operating on a sixty hurts alternating current power system, 194 00:11:22,800 --> 00:11:26,960 Speaker 1: but in Europe they were operating on fifty hurts power systems. 195 00:11:27,160 --> 00:11:29,880 Speaker 1: So just the the frequency of the sound would be 196 00:11:29,960 --> 00:11:32,080 Speaker 1: enough to indicate to you whether you were listening to 197 00:11:32,160 --> 00:11:36,559 Speaker 1: a US ship or a European ship. And uh, you 198 00:11:36,559 --> 00:11:39,160 Speaker 1: couldn't necessarily if everything was running the way it should, 199 00:11:39,360 --> 00:11:41,400 Speaker 1: you might not hear anything at all, or you might 200 00:11:41,480 --> 00:11:44,800 Speaker 1: hear very little. Um. It was if you didn't sound 201 00:11:44,880 --> 00:11:48,080 Speaker 1: proof all of your equipment, like if if the various 202 00:11:48,120 --> 00:11:53,360 Speaker 1: elements weren't uh weren't insulated properly, then stuff would rattle 203 00:11:53,400 --> 00:11:55,600 Speaker 1: and you could you could actually hear the rattling. In fact, 204 00:11:56,120 --> 00:11:59,360 Speaker 1: one source I read said that, uh, you know, the 205 00:11:59,440 --> 00:12:01,800 Speaker 1: location of a submarine might be given away by someone 206 00:12:01,840 --> 00:12:07,120 Speaker 1: accidentally dropping a wrench onto the floor the deck. I guess, um, 207 00:12:07,160 --> 00:12:09,160 Speaker 1: I assume they're decks and submarines I've never been a 208 00:12:09,160 --> 00:12:12,240 Speaker 1: board one. Yes, I believe there are so. Yes, if 209 00:12:12,240 --> 00:12:13,719 Speaker 1: you were to drop a wrench to the deck, it 210 00:12:14,320 --> 00:12:17,240 Speaker 1: could create a sound that someone another sonar operator might 211 00:12:17,280 --> 00:12:18,560 Speaker 1: be able to pick up and say, all right, they're 212 00:12:18,800 --> 00:12:24,160 Speaker 1: they're support um. So it's it's a pretty interesting thing. 213 00:12:24,200 --> 00:12:27,120 Speaker 1: And the passive sonar, by the way, was more important 214 00:12:27,160 --> 00:12:32,040 Speaker 1: for submarines because if they use the active method, they 215 00:12:32,080 --> 00:12:35,640 Speaker 1: would actively be giving away their location. Yes, that's because 216 00:12:35,760 --> 00:12:42,080 Speaker 1: active active sonar systems are giving off a pulse of sound. Yeah, 217 00:12:42,280 --> 00:12:46,160 Speaker 1: often called a ping. Yes, so you ping the sound 218 00:12:46,200 --> 00:12:49,840 Speaker 1: out and uh, and then they wait for the sound 219 00:12:49,840 --> 00:12:53,360 Speaker 1: waves to come back and based upon how long it 220 00:12:53,400 --> 00:12:56,679 Speaker 1: takes and how much how strong the signal is, that's 221 00:12:56,720 --> 00:12:59,720 Speaker 1: how you kind of determine what it is, your your hearing. 222 00:13:00,200 --> 00:13:04,000 Speaker 1: You know how far away the object is, and you 223 00:13:04,040 --> 00:13:07,040 Speaker 1: know what it might be. You know how many how 224 00:13:07,080 --> 00:13:09,480 Speaker 1: many submarine movies have you seen where they do that 225 00:13:09,640 --> 00:13:13,040 Speaker 1: tense moment where nobody's moving a muscle, they don't wait wait, 226 00:13:14,360 --> 00:13:16,160 Speaker 1: you know, and there's just like you know, you watch 227 00:13:16,200 --> 00:13:19,559 Speaker 1: the beads of sweat rolled down the submariner's faces. Yes, 228 00:13:19,640 --> 00:13:22,000 Speaker 1: there's the there's the one that I quoted at the 229 00:13:22,040 --> 00:13:25,719 Speaker 1: beginning of this podcast. Um, yeah, no, no, but there 230 00:13:25,720 --> 00:13:27,880 Speaker 1: are many you know that that then that's the thing 231 00:13:27,960 --> 00:13:29,800 Speaker 1: is you have to be very very quiet and that 232 00:13:29,920 --> 00:13:32,840 Speaker 1: kind of a situation because any little thing can be 233 00:13:32,880 --> 00:13:35,040 Speaker 1: picked up by the ping. And here's what's really interesting 234 00:13:35,640 --> 00:13:39,200 Speaker 1: to me is that the ping is well really anything 235 00:13:39,200 --> 00:13:41,200 Speaker 1: could be picked up by passive sonar. I know, I 236 00:13:41,200 --> 00:13:43,199 Speaker 1: just want to make an Okay, I got you. I 237 00:13:43,280 --> 00:13:48,160 Speaker 1: was about for the rhyme. I sorry, so active, but 238 00:13:48,160 --> 00:13:51,320 Speaker 1: with the rhyme of an ancient you stopped at one 239 00:13:51,360 --> 00:13:53,880 Speaker 1: of three. Chris and I will be back in just 240 00:13:54,040 --> 00:13:57,920 Speaker 1: a moment to continue our discussion about sonar, but first 241 00:13:58,000 --> 00:14:08,240 Speaker 1: let's take a quick break to thank ours. Answer the 242 00:14:08,320 --> 00:14:14,320 Speaker 1: active sonar. The basis of that really rests in the 243 00:14:14,360 --> 00:14:16,840 Speaker 1: fact that we know how fast sound travels through water. 244 00:14:18,120 --> 00:14:22,320 Speaker 1: But we we do, but it's really complicated. You would think, oh, 245 00:14:22,400 --> 00:14:25,880 Speaker 1: it's got to be some constant right, not exactly actually 246 00:14:25,960 --> 00:14:29,800 Speaker 1: constantly constant. Yeah, The speed of sound traveling through water 247 00:14:29,880 --> 00:14:32,960 Speaker 1: depends on several things. Depends on the temperature of the water, 248 00:14:33,520 --> 00:14:36,840 Speaker 1: the salinity of the water, and the depth of the water, 249 00:14:37,560 --> 00:14:41,200 Speaker 1: and all of these things affect the density of the water, 250 00:14:41,280 --> 00:14:44,360 Speaker 1: which makes sense. Right. If you've got more molecules packed together, 251 00:14:44,840 --> 00:14:49,080 Speaker 1: sounds going to travel faster through that because the molecules 252 00:14:49,120 --> 00:14:52,200 Speaker 1: hit each other more quickly, Like it doesn't take much 253 00:14:52,200 --> 00:14:54,760 Speaker 1: for a molecule they'll run into another molecule. The sound 254 00:14:54,800 --> 00:14:58,040 Speaker 1: travels much much further and much faster, um if you've 255 00:14:58,320 --> 00:15:00,800 Speaker 1: got them spread out the and they lose some of 256 00:15:00,840 --> 00:15:04,320 Speaker 1: their energy as they are moving, and so it doesn't 257 00:15:04,360 --> 00:15:08,120 Speaker 1: travels far and it doesn't travels quickly. So the rule 258 00:15:08,120 --> 00:15:10,800 Speaker 1: of thumb is that it's four thousand three eight eight 259 00:15:11,160 --> 00:15:14,080 Speaker 1: feet per second. And then you have to add all 260 00:15:14,080 --> 00:15:17,680 Speaker 1: these modifiers in right right now, there are some some 261 00:15:17,880 --> 00:15:20,800 Speaker 1: things that you can do. Uh. There is a system 262 00:15:21,560 --> 00:15:23,480 Speaker 1: that I read about, the A N B q H 263 00:15:23,640 --> 00:15:28,040 Speaker 1: DASH one speed of Sound measuring system, which is you know, 264 00:15:28,040 --> 00:15:31,840 Speaker 1: a modern sonar system, um. But it evaluates the depth 265 00:15:31,880 --> 00:15:34,920 Speaker 1: and temperature and salinity of the water to get an 266 00:15:34,960 --> 00:15:38,160 Speaker 1: idea of how the speed of sound is going to 267 00:15:38,200 --> 00:15:41,760 Speaker 1: travel through that particular water at the time. Obviously, that's 268 00:15:41,760 --> 00:15:44,120 Speaker 1: probably a very expensive piece of equipment because it's doing 269 00:15:44,120 --> 00:15:47,640 Speaker 1: those calculations for you. But that's what modern computing technology 270 00:15:47,680 --> 00:15:50,960 Speaker 1: gets you. Um. But yeah, it gives you uh, you know, 271 00:15:51,040 --> 00:15:54,320 Speaker 1: sonar technicians can use that equipment to get an idea 272 00:15:54,440 --> 00:15:57,480 Speaker 1: of what's going on with a lot better accuracy, and 273 00:15:57,520 --> 00:16:00,760 Speaker 1: it also helps them avoid being detected by other sonar 274 00:16:00,800 --> 00:16:04,080 Speaker 1: equipment because they have an idea of you know, what's 275 00:16:04,200 --> 00:16:07,240 Speaker 1: the current conditions are underwater where they are, right, So, 276 00:16:07,400 --> 00:16:09,560 Speaker 1: if you're using active sonar, you might be using it 277 00:16:09,600 --> 00:16:13,880 Speaker 1: for well if in wartime you would have ships and 278 00:16:13,880 --> 00:16:17,160 Speaker 1: and even aircraft using active sonar to try and detect 279 00:16:17,200 --> 00:16:21,080 Speaker 1: submarines and then drop depth charges down to to disrupt 280 00:16:21,080 --> 00:16:25,800 Speaker 1: the submarines. Ah yes, uh so active sonar in wartime 281 00:16:25,840 --> 00:16:29,160 Speaker 1: is often used by by vessels that can move fast 282 00:16:29,280 --> 00:16:31,840 Speaker 1: enough so that it's not it's not a big deal 283 00:16:31,840 --> 00:16:35,520 Speaker 1: about giving away your location like destroyers for example. Exactly exactly. 284 00:16:35,680 --> 00:16:38,280 Speaker 1: If you're a submarine, you don't tend to use active 285 00:16:38,320 --> 00:16:41,840 Speaker 1: sonar as often. Um yeah, especially when you're submerged in 286 00:16:41,880 --> 00:16:44,840 Speaker 1: trying to avoid detection, because that's you can't move nearly 287 00:16:44,880 --> 00:16:50,240 Speaker 1: as quickly as the enemy destroyers are coming after you. Right. So, 288 00:16:50,240 --> 00:16:53,000 Speaker 1: so if you're also you could be using active sonar, 289 00:16:53,240 --> 00:16:56,160 Speaker 1: not just in wartime, but also if you're mapping the 290 00:16:56,240 --> 00:16:59,400 Speaker 1: ocean floor then you want you want to be as 291 00:16:59,480 --> 00:17:02,400 Speaker 1: accurate as possible, which means you have to have you know, 292 00:17:02,480 --> 00:17:04,600 Speaker 1: you have to factor in all those elements we were 293 00:17:04,600 --> 00:17:06,800 Speaker 1: talking about before, the salinity and temperature and depth and 294 00:17:06,840 --> 00:17:09,600 Speaker 1: all that. UM. If you if you're just using sonar 295 00:17:09,720 --> 00:17:12,040 Speaker 1: as a fish finder, because there are plenty of of 296 00:17:12,600 --> 00:17:15,119 Speaker 1: products on the market that do that, you don't have 297 00:17:15,160 --> 00:17:18,639 Speaker 1: to worry quite that level of accuracy because you're not 298 00:17:18,720 --> 00:17:21,760 Speaker 1: you're usually not talking about the same kind of distances 299 00:17:21,840 --> 00:17:25,720 Speaker 1: involved that we're talking about, and usually the you know, 300 00:17:25,760 --> 00:17:28,399 Speaker 1: the depth is not as big a factor. So really 301 00:17:28,640 --> 00:17:31,520 Speaker 1: in that case, uh, you know, you could use a 302 00:17:31,560 --> 00:17:34,919 Speaker 1: constant speed for the sound through water and not be 303 00:17:35,080 --> 00:17:38,160 Speaker 1: so inaccurate. There. You're looking for schools of fish. They're 304 00:17:38,200 --> 00:17:40,280 Speaker 1: going to be moving around anyway, so it's not like 305 00:17:40,320 --> 00:17:43,480 Speaker 1: it's um, it's not like like the kind of precision 306 00:17:43,480 --> 00:17:45,960 Speaker 1: work you need to do with these other elements. Right. 307 00:17:46,000 --> 00:17:48,240 Speaker 1: Actually that that's one of the things that I found 308 00:17:48,240 --> 00:17:54,240 Speaker 1: fascinating during part of the the sentar technicians training. They actually, 309 00:17:54,359 --> 00:17:59,919 Speaker 1: uh are known to record things that are just natural sound, 310 00:18:00,520 --> 00:18:06,080 Speaker 1: like the sounds of fish, um tectonic plates. I'm not 311 00:18:06,760 --> 00:18:08,600 Speaker 1: I'm not sure what kinds of sounds does give off 312 00:18:09,040 --> 00:18:12,639 Speaker 1: really low groaning ones, yes, kind of like my back. 313 00:18:12,960 --> 00:18:16,880 Speaker 1: But that's but that's the the trick is you once 314 00:18:16,920 --> 00:18:20,119 Speaker 1: they understand what those things are, they can eliminate them. 315 00:18:20,160 --> 00:18:22,400 Speaker 1: They go, oh, well, that's just a large school of fish, 316 00:18:23,000 --> 00:18:25,640 Speaker 1: you know. Oh that's you know, an alien spaceship that's 317 00:18:25,640 --> 00:18:30,440 Speaker 1: crashed underwater, that kind of stuff. Um, I make a joke, 318 00:18:30,640 --> 00:18:33,440 Speaker 1: but no, that that that Uh. I was wondering about 319 00:18:33,440 --> 00:18:36,199 Speaker 1: that when I was reading about civilian uses for so 320 00:18:36,280 --> 00:18:37,919 Speaker 1: in our technology, and I was thinking, wow, how do 321 00:18:37,960 --> 00:18:40,560 Speaker 1: they know, you know, what is a school of fish? 322 00:18:40,560 --> 00:18:43,639 Speaker 1: And obviously if you're on a lake and it's it's 323 00:18:43,640 --> 00:18:46,080 Speaker 1: probably going to be the stuff that's moving around underwater. 324 00:18:46,240 --> 00:18:48,879 Speaker 1: It's not likely to be an enemy submarine. But you know, 325 00:18:49,359 --> 00:18:52,640 Speaker 1: detecting a fish versus you know, a snake or some 326 00:18:52,680 --> 00:18:57,879 Speaker 1: other type of monster, we've gotten very silly, very quickly. 327 00:18:58,119 --> 00:19:00,639 Speaker 1: Well no, I mean people have been used saying that 328 00:19:00,720 --> 00:19:02,919 Speaker 1: kind of equipment to try and determine whether or not 329 00:19:02,960 --> 00:19:06,480 Speaker 1: there are yeah, so our equipment. Yes, there are plenty 330 00:19:06,680 --> 00:19:09,879 Speaker 1: of monster hunters who have tried to use like a 331 00:19:09,920 --> 00:19:14,200 Speaker 1: fish finder, yeah essentially. But that's the thing is that there. 332 00:19:14,200 --> 00:19:16,760 Speaker 1: There are schools of fish in Locknest and schools of 333 00:19:16,760 --> 00:19:20,360 Speaker 1: eels as well, So you get a school of fish 334 00:19:20,480 --> 00:19:21,840 Speaker 1: or a school of eels that's going to give you 335 00:19:21,880 --> 00:19:23,480 Speaker 1: a reading. And then people say, hey, look there's a 336 00:19:23,480 --> 00:19:26,880 Speaker 1: monster down there. Not necessarily and I have to say, 337 00:19:26,920 --> 00:19:29,000 Speaker 1: you know, I've mentioned before in the podcast that I'm 338 00:19:29,000 --> 00:19:32,800 Speaker 1: a skeptic. Out of all the things to be skeptical about, 339 00:19:32,880 --> 00:19:35,160 Speaker 1: the lock best monster was the one I held onto 340 00:19:35,200 --> 00:19:37,959 Speaker 1: the longest because I want to believe it's real. I 341 00:19:38,040 --> 00:19:41,680 Speaker 1: don't believe it's real, but I want to so badly. 342 00:19:43,480 --> 00:19:46,439 Speaker 1: UM and a cottage on the shore. There's a shadow 343 00:19:46,480 --> 00:19:50,480 Speaker 1: on the door. No different kinds of sonar okay, side 344 00:19:50,520 --> 00:19:55,000 Speaker 1: scan center UM. This is a device used to find 345 00:19:55,480 --> 00:19:57,680 Speaker 1: objects on the sea floor and figure out what they are. 346 00:19:58,160 --> 00:20:01,120 Speaker 1: They usually have a tow fish or a tow body, 347 00:20:01,240 --> 00:20:05,520 Speaker 1: which is a UM basically sophisticated device that goes in 348 00:20:05,560 --> 00:20:08,240 Speaker 1: the water and is towed behind the ship, and a 349 00:20:08,240 --> 00:20:11,399 Speaker 1: device that processes the signals on the top UM. What 350 00:20:11,480 --> 00:20:15,720 Speaker 1: happens is they use the the sound energy which is 351 00:20:15,760 --> 00:20:19,359 Speaker 1: transmitted in a fan shaped pattern and goes about a 352 00:20:19,400 --> 00:20:24,440 Speaker 1: hundred meters down or so. Basically, they used the information 353 00:20:24,440 --> 00:20:27,879 Speaker 1: that comes back to create an image of what's on 354 00:20:27,920 --> 00:20:30,119 Speaker 1: the sea floor. So if they get a really strong 355 00:20:30,200 --> 00:20:35,199 Speaker 1: signal um back, that appears as a light image on 356 00:20:35,240 --> 00:20:40,240 Speaker 1: the screen, whereas weaker signal would show darker images. So 357 00:20:40,320 --> 00:20:42,919 Speaker 1: you get uh, sort of a black and white image. 358 00:20:43,080 --> 00:20:45,720 Speaker 1: I don't know if it's actually black and white, because 359 00:20:45,720 --> 00:20:48,160 Speaker 1: I was reading copy and it might be photo bright 360 00:20:48,200 --> 00:20:50,520 Speaker 1: green and dull, right right, But you can get an 361 00:20:50,520 --> 00:20:54,000 Speaker 1: idea of what the the bottom of the area you're 362 00:20:54,000 --> 00:20:55,439 Speaker 1: looking at. I guess it could be a lake or 363 00:20:55,480 --> 00:20:58,640 Speaker 1: the ocean. Um they don't they don't offer the same 364 00:20:58,720 --> 00:21:02,439 Speaker 1: kind of depth information as the military would use to say, oh, 365 00:21:02,480 --> 00:21:05,000 Speaker 1: well we you know, we're about to run around. It's 366 00:21:05,040 --> 00:21:08,760 Speaker 1: not the same kind of application of sonar. Also, we 367 00:21:08,800 --> 00:21:11,680 Speaker 1: should add that at certain depths, once you get really 368 00:21:11,720 --> 00:21:13,960 Speaker 1: really deep, the water gets so dense that it can 369 00:21:14,000 --> 00:21:17,919 Speaker 1: refract sound waves. So you you start to lose the 370 00:21:17,960 --> 00:21:21,479 Speaker 1: ability to really map the ocean floor with sound because 371 00:21:22,560 --> 00:21:26,080 Speaker 1: the water itself is so dense that it's it's it's 372 00:21:26,160 --> 00:21:29,440 Speaker 1: mucking things up. Also, I guess I should go ahead 373 00:21:29,440 --> 00:21:31,520 Speaker 1: and mention as well. We've talked a lot about the sonar. 374 00:21:31,600 --> 00:21:34,520 Speaker 1: The sonar really has three main elements to it. Yes, 375 00:21:34,560 --> 00:21:38,320 Speaker 1: there's a transmitter which transmits the sound right right, we 376 00:21:38,320 --> 00:21:40,640 Speaker 1: didn't really talk about it, but there's a transmitter that's 377 00:21:40,680 --> 00:21:44,040 Speaker 1: that's what passes on the signal. UH. It's an electric 378 00:21:44,080 --> 00:21:47,160 Speaker 1: signal that goes to a transducer. Now, transducers, what they 379 00:21:47,200 --> 00:21:50,040 Speaker 1: do is they convert one kind of energy into another 380 00:21:50,119 --> 00:21:52,920 Speaker 1: kind of energy. In the case of sonar, it's converting 381 00:21:53,040 --> 00:21:56,760 Speaker 1: sound electricity rather into sound, right active for this is 382 00:21:56,760 --> 00:21:59,960 Speaker 1: for active sonar clearly. And then you've got to receive 383 00:22:00,080 --> 00:22:02,600 Speaker 1: or that receives the signals when they come back, um 384 00:22:02,640 --> 00:22:06,400 Speaker 1: and and then you usually have a display. So there's 385 00:22:06,400 --> 00:22:10,680 Speaker 1: a transmitter, transducer, and receiver. This is for again active sonar. 386 00:22:10,880 --> 00:22:15,439 Speaker 1: With the passive sonar, you just need receivers really microphones, hydrophones, 387 00:22:16,000 --> 00:22:19,479 Speaker 1: um and and there are plenty of stationary UH sonar 388 00:22:20,040 --> 00:22:24,679 Speaker 1: UH stations, and I guess stationary stations, thank you, Jonathan, 389 00:22:24,720 --> 00:22:27,360 Speaker 1: you're both repetitive and redundant. But at any rate, there 390 00:22:27,359 --> 00:22:30,280 Speaker 1: are plenty of these in the ocean. The lots of 391 00:22:30,280 --> 00:22:34,679 Speaker 1: different militaries have them station stationed at different spots along 392 00:22:34,720 --> 00:22:40,399 Speaker 1: the coast to detect things like possible incoming submarines, that 393 00:22:40,480 --> 00:22:42,800 Speaker 1: kind of thing. We have a bit more to say 394 00:22:42,880 --> 00:22:45,880 Speaker 1: about sonar technology, but before we get to that, let's 395 00:22:45,920 --> 00:22:56,800 Speaker 1: take another quick break to thank our sponsor. There was 396 00:22:56,840 --> 00:23:00,760 Speaker 1: a sound detective in n It was actually detected several 397 00:23:00,760 --> 00:23:05,199 Speaker 1: times over the summer of U in the Pacific Ocean 398 00:23:06,080 --> 00:23:11,240 Speaker 1: by by a hydrophone array, and the sound was a 399 00:23:11,359 --> 00:23:17,080 Speaker 1: very low frequency sound generated over a pretty extended uh 400 00:23:17,480 --> 00:23:21,520 Speaker 1: time frame several I think it's several minutes long, and 401 00:23:21,600 --> 00:23:26,679 Speaker 1: it's called the bloop. The bloop is um this odd 402 00:23:26,720 --> 00:23:30,439 Speaker 1: sound that that we're not really sure what made this noise. 403 00:23:30,680 --> 00:23:33,240 Speaker 1: If it was organic, then it would have to be 404 00:23:33,280 --> 00:23:37,600 Speaker 1: a creature larger than any that we've previously identified. So 405 00:23:37,720 --> 00:23:39,199 Speaker 1: if it were a whale, it would have to be 406 00:23:39,240 --> 00:23:44,639 Speaker 1: such an enormous whale that we've never seen it. Uh Ever, Yeah, 407 00:23:44,840 --> 00:23:48,760 Speaker 1: so it would be be ginormous, right to use the 408 00:23:48,800 --> 00:23:53,520 Speaker 1: technical term. It's more likely that the bloop is ah 409 00:23:53,800 --> 00:23:57,680 Speaker 1: was some sort of geological byproduct, right, But at any rate, 410 00:23:57,760 --> 00:24:01,480 Speaker 1: this sound was located or the location of the sound 411 00:24:01,560 --> 00:24:04,640 Speaker 1: is probably somewhere around fifty degrees south hundred degrees west. 412 00:24:05,440 --> 00:24:11,360 Speaker 1: What's interesting to lovecraft Ian fans is that that's not 413 00:24:11,800 --> 00:24:16,680 Speaker 1: that far off from the supposed coordinates of Reallyer, which 414 00:24:16,720 --> 00:24:21,080 Speaker 1: is Cathulu's city of the Deep. So some people have jokingly, 415 00:24:21,560 --> 00:24:25,879 Speaker 1: tongue in cheek, said that this noise was dead Cathulu 416 00:24:26,000 --> 00:24:30,480 Speaker 1: snoring because in his house, and really dead Cathul lies dreaming. 417 00:24:31,119 --> 00:24:34,960 Speaker 1: Alright then, and also, let's some we can actually play 418 00:24:35,000 --> 00:24:36,639 Speaker 1: the sounds. So what we're gonna do here is we're 419 00:24:36,640 --> 00:24:38,440 Speaker 1: gonna just take a second. We're gonna play the sound. 420 00:24:38,680 --> 00:24:41,399 Speaker 1: This is a sound that's off of the U. S. 421 00:24:41,480 --> 00:24:46,479 Speaker 1: Government's websites, and it is specifically the sound sped up 422 00:24:47,000 --> 00:25:00,280 Speaker 1: sixteen times. Now, I don't know about you. I think 423 00:25:00,280 --> 00:25:03,440 Speaker 1: that was I was pretty certain it was a bunch 424 00:25:03,480 --> 00:25:05,720 Speaker 1: of people flushing all at the same time. Could have 425 00:25:05,760 --> 00:25:08,000 Speaker 1: also been that it might have been during the Super Bowl. Wait, 426 00:25:08,040 --> 00:25:09,960 Speaker 1: it was the summer of ninety seven, so it couldn't 427 00:25:10,000 --> 00:25:12,040 Speaker 1: have been. I don't know anything about sports, but even 428 00:25:12,160 --> 00:25:16,119 Speaker 1: I know it doesn't happen in the summer. It was 429 00:25:16,160 --> 00:25:18,679 Speaker 1: world it was the World Cup, except that wouldn't have been. 430 00:25:19,080 --> 00:25:22,800 Speaker 1: It wouldn't have been a World Cup. Okay, so our 431 00:25:22,840 --> 00:25:26,880 Speaker 1: speculation goes awry. Also, we had someone on Facebook, I think, 432 00:25:26,920 --> 00:25:29,479 Speaker 1: asked us about the blue. Yes, there that goes and 433 00:25:29,480 --> 00:25:33,200 Speaker 1: that goes out to you random Facebook person. All right, 434 00:25:34,359 --> 00:25:37,600 Speaker 1: um so, uh, you know, I did look up some 435 00:25:37,640 --> 00:25:41,520 Speaker 1: other interesting related technology like lidar, which is a light 436 00:25:41,560 --> 00:25:45,639 Speaker 1: detected light detection and ranging system. Doesn't use sound, he 437 00:25:45,720 --> 00:25:50,240 Speaker 1: uses light, but it is used mathemetric lighter is used 438 00:25:50,240 --> 00:25:53,560 Speaker 1: to determine the depth of water. UM. It uses lasers, 439 00:25:53,600 --> 00:25:56,720 Speaker 1: pulses of lasers sent out at two frequencies. UM. There's 440 00:25:56,720 --> 00:25:59,240 Speaker 1: an infrared pulse which is a lower frequency and it 441 00:25:59,320 --> 00:26:02,199 Speaker 1: reflects the surface, so you know where the surface of 442 00:26:02,200 --> 00:26:05,119 Speaker 1: the water is. And then it uses green lasers that 443 00:26:05,240 --> 00:26:08,199 Speaker 1: have a higher frequency that reflects off the bottom of 444 00:26:08,240 --> 00:26:11,960 Speaker 1: the area. Interesting, and it works pretty similar to echolocation 445 00:26:12,000 --> 00:26:14,280 Speaker 1: because it's getting reading for the top and the bottom 446 00:26:14,320 --> 00:26:16,320 Speaker 1: of the depth, so you get an idea of how 447 00:26:16,320 --> 00:26:19,760 Speaker 1: deep the water is. And they use this um from 448 00:26:20,040 --> 00:26:26,439 Speaker 1: aerially generally, well from their mounted on aircraft. Um so 449 00:26:27,040 --> 00:26:30,840 Speaker 1: according to Noah, and I mean the National Oceanic and 450 00:26:30,840 --> 00:26:34,720 Speaker 1: Atmospheric Administration, not the guy with the big boat. That's 451 00:26:34,760 --> 00:26:36,680 Speaker 1: the second time you've made that joke on this pod, 452 00:26:36,840 --> 00:26:39,560 Speaker 1: not this particular episode, but in the series. Yeah, well 453 00:26:39,720 --> 00:26:42,600 Speaker 1: you know, but yeah, and depending on how clear the 454 00:26:42,640 --> 00:26:45,439 Speaker 1: water is, they can determine depths up to fifty and 455 00:26:45,480 --> 00:26:49,200 Speaker 1: this is really useful for those, uh, really hazardous areas 456 00:26:50,400 --> 00:26:53,520 Speaker 1: where it's might be difficult to get a reading from 457 00:26:53,800 --> 00:26:57,800 Speaker 1: a vessel water borne vessel. It would be dangerous put 458 00:26:57,800 --> 00:27:00,480 Speaker 1: a ship there exactly reefs and shoal and that sort 459 00:27:00,520 --> 00:27:02,440 Speaker 1: of thing, which is exactly why you'd want to know 460 00:27:02,880 --> 00:27:06,080 Speaker 1: what it's like, you know, underneath the surface of the water, 461 00:27:06,080 --> 00:27:08,600 Speaker 1: so you can get an idea for navigation purpose. I 462 00:27:08,600 --> 00:27:11,800 Speaker 1: mean really sonar Just don't mean to interrupt, but the 463 00:27:11,800 --> 00:27:14,919 Speaker 1: reason why sonar it was so important early on is 464 00:27:14,960 --> 00:27:18,600 Speaker 1: because light does not travel through water very well, like 465 00:27:18,760 --> 00:27:20,879 Speaker 1: just normal light. And you know, you go down just 466 00:27:20,960 --> 00:27:24,040 Speaker 1: a couple hundred feet and it's it gets dark really fast. 467 00:27:24,560 --> 00:27:27,720 Speaker 1: And anybody who's swam in the Atlantic Ocean knows that 468 00:27:27,800 --> 00:27:31,160 Speaker 1: it's not exactly the clearest water. Uh so it will 469 00:27:31,160 --> 00:27:33,680 Speaker 1: be especially difficult to see in in you know, water 470 00:27:33,720 --> 00:27:37,040 Speaker 1: with a lot of salinity and trabidity. And of course 471 00:27:37,080 --> 00:27:40,359 Speaker 1: if you get it at pretty intense depths, then you 472 00:27:40,400 --> 00:27:43,280 Speaker 1: don't want to have any windows in your device at 473 00:27:43,280 --> 00:27:47,960 Speaker 1: all because the pressure is too great. Um. Before we 474 00:27:48,000 --> 00:27:50,280 Speaker 1: get to the next segment. Sure, I was going to 475 00:27:50,400 --> 00:27:52,600 Speaker 1: mention too that you can you can actually use sonar 476 00:27:52,720 --> 00:27:56,760 Speaker 1: from uh, you know, from the air as well. If 477 00:27:56,800 --> 00:28:01,520 Speaker 1: you're using a sona boy, which is basically a buoy 478 00:28:01,560 --> 00:28:04,119 Speaker 1: that is equipped with sowner equipment that is lowered I 479 00:28:04,119 --> 00:28:07,000 Speaker 1: guess by helicopter would probably be the best. Uh. That's 480 00:28:07,000 --> 00:28:10,000 Speaker 1: where I've actually seen it down where they lower it 481 00:28:10,040 --> 00:28:12,200 Speaker 1: into you know, so there's floating on the surface of 482 00:28:12,200 --> 00:28:15,119 Speaker 1: the water that they can get readings UM from anything 483 00:28:15,160 --> 00:28:17,280 Speaker 1: that might be in the area. Yeah, that's pretty cool. 484 00:28:17,400 --> 00:28:20,800 Speaker 1: That's often used in wartime as well, because it's a 485 00:28:20,840 --> 00:28:23,000 Speaker 1: way for you know, you send a helicopter out to 486 00:28:23,040 --> 00:28:25,359 Speaker 1: the general region where you believe there's a submarine. You 487 00:28:25,440 --> 00:28:27,920 Speaker 1: use these to try and locate the submarine. Then you 488 00:28:28,040 --> 00:28:30,879 Speaker 1: use the depth charges, which are really just explosives that 489 00:28:30,880 --> 00:28:34,280 Speaker 1: that sink into the water before exploding UM and then 490 00:28:34,400 --> 00:28:39,160 Speaker 1: try to damage or or disrupt the submarine in some 491 00:28:39,280 --> 00:28:43,160 Speaker 1: way whereas the submarine is trying desperately to or the 492 00:28:43,160 --> 00:28:46,080 Speaker 1: people in the submarine anyway, or trying desperately to avoid detection, 493 00:28:46,200 --> 00:28:49,600 Speaker 1: or you know, sometimes they'll use things like UM decoy 494 00:28:49,720 --> 00:28:53,760 Speaker 1: explosions so you create enough noise in the water, and 495 00:28:53,760 --> 00:29:00,000 Speaker 1: it becomes very difficult to pinpoint a specific object. Um 496 00:29:00,040 --> 00:29:03,000 Speaker 1: And I know you wanted to discuss that it's not 497 00:29:03,080 --> 00:29:06,200 Speaker 1: all that sonar is not all necessarily beneficial, that it 498 00:29:06,240 --> 00:29:08,719 Speaker 1: can actually have a negative impact on the environment. Right, 499 00:29:08,880 --> 00:29:12,360 Speaker 1: we're actually the creatures living in the environment. We mentioned 500 00:29:12,400 --> 00:29:16,200 Speaker 1: that that whales and dolphins use echolocation in order to 501 00:29:16,600 --> 00:29:20,800 Speaker 1: navigate their environments. Um. Sometimes there have been reports that 502 00:29:20,800 --> 00:29:25,760 Speaker 1: that the low frequencies used in sonar equipment have disrupted 503 00:29:25,800 --> 00:29:29,800 Speaker 1: that they're this marine life. That in some cases there 504 00:29:29,840 --> 00:29:33,480 Speaker 1: may be instances where it has spooped a pot of 505 00:29:33,480 --> 00:29:38,040 Speaker 1: whales for example, and and and so there there's some 506 00:29:38,120 --> 00:29:41,760 Speaker 1: studies that suggest that some whales are suffering from a 507 00:29:41,880 --> 00:29:46,760 Speaker 1: kind of um uh well, sort of a pressurization sickness 508 00:29:46,800 --> 00:29:51,360 Speaker 1: because they're surfacing so quickly that they are uh it's 509 00:29:51,400 --> 00:29:54,360 Speaker 1: kind of like whales getting the bends. Yeah, actually it's 510 00:29:54,360 --> 00:29:57,640 Speaker 1: exactly like welles getting the bens. Because the report I 511 00:29:57,680 --> 00:30:03,440 Speaker 1: saw was actually from a uh UK organization called Marine Connection, 512 00:30:04,200 --> 00:30:10,880 Speaker 1: which is a pro um water life organization, and they 513 00:30:11,560 --> 00:30:15,240 Speaker 1: had cited to study from the magazine Nature from two 514 00:30:15,280 --> 00:30:18,840 Speaker 1: thousand three, which was citing an instance in which ten 515 00:30:18,960 --> 00:30:22,600 Speaker 1: beaked whales UH surface too quickly off the Canary Islands 516 00:30:23,440 --> 00:30:26,640 Speaker 1: UM in two thousand two and they got the bends. 517 00:30:26,760 --> 00:30:29,880 Speaker 1: The whales got the bends. And apparently the situation is 518 00:30:31,000 --> 00:30:35,719 Speaker 1: especially prominent for deep diving animals such as a beaked whale, 519 00:30:36,360 --> 00:30:41,760 Speaker 1: and it may be related to the terrain underneath the water. 520 00:30:41,840 --> 00:30:46,080 Speaker 1: If it's really steep um sharp drop off, that may 521 00:30:46,120 --> 00:30:50,000 Speaker 1: affect the way that the sound waves are traveling underwater 522 00:30:50,160 --> 00:30:55,160 Speaker 1: and maybe especially confusing um no. UH also mentioned that 523 00:30:55,200 --> 00:31:00,440 Speaker 1: there might be problems for deep diving species, but said 524 00:31:00,520 --> 00:31:03,600 Speaker 1: that more study needs to be done on on these 525 00:31:03,680 --> 00:31:06,440 Speaker 1: kinds of strandings to find out if it's limited to 526 00:31:06,560 --> 00:31:09,640 Speaker 1: the surroundings, if it actually is the c floor that 527 00:31:09,800 --> 00:31:12,720 Speaker 1: is playing into it, or whether it is strictly the 528 00:31:12,760 --> 00:31:16,160 Speaker 1: sonar itself. You know, before they can make a decision 529 00:31:16,160 --> 00:31:20,160 Speaker 1: as to what's going on. But the Marine Connection has 530 00:31:20,680 --> 00:31:25,560 Speaker 1: asked the UH. UM they've actually gotten involved and suggested 531 00:31:25,600 --> 00:31:27,840 Speaker 1: to the European Parliament and it asked for a ban 532 00:31:28,000 --> 00:31:33,280 Speaker 1: on high intensity sonar in certain areas. UM. So you know, 533 00:31:33,320 --> 00:31:36,920 Speaker 1: there there are concerns that it may cause UH some 534 00:31:36,920 --> 00:31:40,720 Speaker 1: some harm. Basically that they can swim into uh, dangerous 535 00:31:40,800 --> 00:31:43,000 Speaker 1: terrain to it. That is also an issue. If they're 536 00:31:43,120 --> 00:31:46,920 Speaker 1: they're momentarily confused, but in dangerous waters, that could be 537 00:31:47,040 --> 00:31:49,880 Speaker 1: long enough for there to be a serious problem. Right, 538 00:31:50,400 --> 00:31:53,560 Speaker 1: So yeah, there there are some concerns about this technology, 539 00:31:53,600 --> 00:31:57,120 Speaker 1: which you know, we've been using for almost a century 540 00:31:57,160 --> 00:32:01,600 Speaker 1: now regularly. Yeah, and we're still some of them, like 541 00:32:01,680 --> 00:32:04,240 Speaker 1: the passive systems. Of course, that's not a problem because 542 00:32:04,240 --> 00:32:06,840 Speaker 1: the passive systems, all they're doing is listening. They're not 543 00:32:06,880 --> 00:32:10,480 Speaker 1: sending out any signals. So not all sonar is bad 544 00:32:10,560 --> 00:32:13,520 Speaker 1: sonar even from a marine life standpoint. Oh no, it's 545 00:32:13,520 --> 00:32:16,960 Speaker 1: still an incredibly useful technology, right, you just have to 546 00:32:17,040 --> 00:32:19,840 Speaker 1: learn how to use it responsibly so that you're not 547 00:32:20,040 --> 00:32:25,280 Speaker 1: causing harm to the environment or to marine life in particular. Well, 548 00:32:25,320 --> 00:32:28,440 Speaker 1: that wraps up this classic episode of tech Stuff how 549 00:32:28,560 --> 00:32:31,360 Speaker 1: sonar works. It was fun to go back and revisit 550 00:32:31,400 --> 00:32:35,760 Speaker 1: that and listen to a version of Jonathan that's eight 551 00:32:35,920 --> 00:32:41,120 Speaker 1: years younger than I am today. Holy cal Uh. I 552 00:32:41,200 --> 00:32:44,280 Speaker 1: look forward to bringing you more of these classic episodes 553 00:32:44,280 --> 00:32:47,440 Speaker 1: in the future. If you have any suggestions of topics 554 00:32:47,440 --> 00:32:50,120 Speaker 1: that should cover in current episodes of tech Stuff, because 555 00:32:50,680 --> 00:32:53,400 Speaker 1: new splash. I cannot travel back in time and record 556 00:32:53,440 --> 00:32:57,120 Speaker 1: a new classic episode that that the way Back Machine 557 00:32:57,160 --> 00:32:59,600 Speaker 1: will not let me do that. It's apparently some sort 558 00:32:59,640 --> 00:33:02,000 Speaker 1: of I don't know. They call it a Grandma paradox. 559 00:33:02,040 --> 00:33:04,320 Speaker 1: I don't understand. 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