WEBVTT - The Future of Sound: Part One 0:00:00.160 --> 0:00:07.080 Brought to you by Toyota. Let's go places. Welcome to 0:00:07.280 --> 0:00:14.120 Forward Thinking. Hey, they're in. Welcome to Forward Thinking, the 0:00:14.320 --> 0:00:16.880 podcast that looks at the future and says, I will 0:00:16.920 --> 0:00:20.440 sit right down waiting for the gift of sound. I'm 0:00:20.520 --> 0:00:26.639 Jonathan Strickland and I'm Joe McCormick, and today we're gonna 0:00:26.680 --> 0:00:32.320 be talking about the future of sound. And there's a 0:00:32.479 --> 0:00:35.160 very good reason that we're talking about that today, which 0:00:35.159 --> 0:00:37.639 is that I've had a cold all week and I'm 0:00:37.680 --> 0:00:40.199 afraid that my voice in my mouth is going to 0:00:40.320 --> 0:00:43.040 sound bizarre. On the other end of this, I don't 0:00:43.080 --> 0:00:47.280 you know, you never really tell what you yourself sound like. People. 0:00:47.320 --> 0:00:51.960 You are sounding a little bit more of vibrato than usual, Well, 0:00:52.040 --> 0:00:55.280 that may just be my opera singing that I've been practicing. 0:00:55.280 --> 0:00:57.800 On the side, we're also recording earlier in the day 0:00:57.840 --> 0:01:00.280 than we usually do, so that could affect our sound. 0:01:00.320 --> 0:01:02.680 That is, I'm actually really surprised that I don't sound 0:01:02.680 --> 0:01:06.759 like Tom Waits right now. Usually usually before like one pm, 0:01:06.920 --> 0:01:14.000 the microphones have been drinking. Yeah, whenever, whenever I think 0:01:14.000 --> 0:01:16.520 about the future of sound, the thing that I hope 0:01:16.680 --> 0:01:20.040 that they come up with is a device that actually 0:01:20.120 --> 0:01:23.120 makes your voice sound the way it sounds in your head, 0:01:23.440 --> 0:01:27.040 so as you sounds as good as you do inside 0:01:27.120 --> 0:01:29.480 of your your head, as opposed to listening back to 0:01:29.480 --> 0:01:31.679 a recording and thinking, oh, that's not what I sound like, 0:01:31.840 --> 0:01:35.600 is it. Yeah, Today, we wanted to really look into 0:01:36.319 --> 0:01:39.080 different uses of sound. I mean, sound clearly is a 0:01:39.240 --> 0:01:43.240 very powerful thing, and in multiple ways, Like it can 0:01:43.240 --> 0:01:48.040 be figuratively powerful, like you hear something truly moving and 0:01:48.120 --> 0:01:50.680 you have an emotional response to it, or it can 0:01:50.720 --> 0:01:55.760 be physically literally powerful, like the shock way from a 0:01:55.800 --> 0:01:59.440 sonic boom, which can shatter glass or even knock you 0:01:59.520 --> 0:02:02.760 over depending upon the power of it and how close 0:02:02.840 --> 0:02:05.640 you are to the shock wave. I mean, it literally 0:02:05.680 --> 0:02:08.799 has physical power. So we're gonna really look into some 0:02:08.919 --> 0:02:11.639 cool uses for sound in the future, and we have 0:02:11.800 --> 0:02:14.280 so many of them that this is the first part 0:02:14.480 --> 0:02:18.160 of a two part episode. Thank you for pointing that out, Law, 0:02:18.240 --> 0:02:20.640 and so we don't remember halfway through and then go 0:02:21.040 --> 0:02:24.760 have to go back and say that all over. That's right, 0:02:24.800 --> 0:02:27.799 So we've got a lot to say now. The video 0:02:27.880 --> 0:02:31.440 episode that goes along with this, this pair of audio 0:02:31.480 --> 0:02:35.600 podcast I cover three interesting things about sound in the future. 0:02:35.840 --> 0:02:38.400 And we're gonna go more in depth on all of 0:02:38.440 --> 0:02:41.160 those as well as additional ones, because, as I said 0:02:41.160 --> 0:02:45.560 in the video, there's so many potential uses and things 0:02:45.600 --> 0:02:48.720 that we're learning about sound that it's really the stuff 0:02:48.760 --> 0:02:50.720 I talked about in that episodes, just the tip of 0:02:50.760 --> 0:02:53.440 the iceberg. But before we get into all of that, 0:02:54.080 --> 0:02:57.280 I think it would be beneficial for us to actually 0:02:57.360 --> 0:03:01.440 learn what sound is, how it works, because that will 0:03:01.520 --> 0:03:04.960 go on to inform, uh, the other stories we talk 0:03:05.040 --> 0:03:11.320 about and how we're making an innovative use of sound. Right, So, 0:03:11.320 --> 0:03:14.840 sound is the magic produced by the music of the 0:03:15.000 --> 0:03:19.560 sphere vibrating on the fourth harmony. You watched that April 0:03:19.560 --> 0:03:24.359 Fool's episode of for Thinking way too many times? Um, Yes, 0:03:24.480 --> 0:03:28.040 the character from that episode would certainly agree with you. However, 0:03:28.080 --> 0:03:32.840 if we want to get a little more scientific, Yeah, 0:03:33.000 --> 0:03:36.080 we're talking about sound being that's that's what's produced when stuff, 0:03:36.280 --> 0:03:42.080 when matter vibrates, all right, that's that's your basic definition. 0:03:42.120 --> 0:03:46.280 When matter vibrates, it produces sound. Whether there's anyone there 0:03:46.320 --> 0:03:48.640 to hear it, who's to say so if a tree 0:03:48.640 --> 0:03:51.800 falls in the forest, it does make a sound. You 0:03:51.880 --> 0:03:54.280 might not be there to perceive it, But it happens 0:03:54.800 --> 0:03:59.560 um So stuff vibrates at certain frequencies which are completely 0:03:59.560 --> 0:04:03.400 determined by the physical properties and the parameters of that stuff. 0:04:03.880 --> 0:04:07.320 This is called the resonant frequency, right Like how dense 0:04:07.360 --> 0:04:11.560 it is or the temperature of the of the matter 0:04:11.680 --> 0:04:16.400 can can determine it. The actual physical structure, whether it's 0:04:16.400 --> 0:04:19.520 a crystalline structure or not, that can determine it as well. 0:04:19.839 --> 0:04:23.160 If you're talking about air, like the humidity, the water content, 0:04:23.200 --> 0:04:28.400 and exactly so when we talk about the speed of sound, 0:04:28.560 --> 0:04:31.920 which will get more into in a little bit, little 0:04:32.120 --> 0:04:34.880 tiny things can make a difference. Now it might not 0:04:34.960 --> 0:04:39.640 be perceptible to we mirror mortals because we're not capable 0:04:39.680 --> 0:04:45.120 of detecting millisecond you know, differences in speed, but the altitude, 0:04:45.200 --> 0:04:48.440 the density of the air obviously would go along with that. 0:04:48.440 --> 0:04:51.760 That has an effect. The temperature, the humidity, all of 0:04:51.800 --> 0:04:56.120 these things can affect the speed of sounds. So when 0:04:56.200 --> 0:04:59.640 something vibrates like a drum, if you strike that drum, 0:04:59.640 --> 0:05:02.600 it's gonna vibrate at its resonant frequency. Same sort of 0:05:02.600 --> 0:05:04.640 thing like if you tap a glass and they hear 0:05:04.680 --> 0:05:08.080 that little tinging sound, it's going to be vibrating at 0:05:08.080 --> 0:05:11.640 that resonant frequency, and that sound will be consistent. So 0:05:11.680 --> 0:05:13.760 if you hit it again, it's going to make that 0:05:13.839 --> 0:05:18.159 same sound unless you change the parameters of that object. 0:05:18.240 --> 0:05:20.400 So like with a drum, if you were too tighten 0:05:20.600 --> 0:05:24.200 or or loosen the drumhead, you would get a different 0:05:24.279 --> 0:05:26.279 sound the next time you strike it because you've actually 0:05:26.320 --> 0:05:29.280 changed the physical parameters of that matter, or if you 0:05:29.320 --> 0:05:35.120 strike it with a different stick, different speed. Technically, the 0:05:35.160 --> 0:05:37.760 actual frequency of the sound should be more or less 0:05:37.800 --> 0:05:41.400 the same. Now, the amplitude will be different, but the 0:05:41.440 --> 0:05:45.320 frequency at which it vibrates apart from the initial contact. 0:05:45.400 --> 0:05:48.760 When the initial contact happens, you're actively introducing a bit 0:05:48.800 --> 0:05:51.640 of a random event to that matter, but it will 0:05:51.760 --> 0:05:54.800 settle into the frequency. Because it's really easy to make 0:05:54.839 --> 0:05:59.040 matter vibrate at its resonant frequency and really hard to 0:05:59.080 --> 0:06:02.760 make it vibrate at any other frequency. It's one of 0:06:02.800 --> 0:06:06.240 the things about resonance that's really interesting. Now you can 0:06:06.400 --> 0:06:10.000 do it, but it takes more effort, and as we know, 0:06:10.240 --> 0:06:13.880 based upon the laws of physics, things tend to kind 0:06:13.920 --> 0:06:17.799 of move to the easiest state. Right if it takes 0:06:17.839 --> 0:06:21.320 more energy than interpetes like no, no, no, no, no, no, no, 0:06:21.400 --> 0:06:23.800 I was kind of thinking about the difference between drumming 0:06:23.800 --> 0:06:26.760 with sticks and drumming with brushes. Sure. Yeah, Now, the 0:06:26.760 --> 0:06:28.719 actual frequencies, if you got down to a point where 0:06:28.720 --> 0:06:30.640 you were measuring the sound waves, you would see that 0:06:30.680 --> 0:06:33.760 the frequencies would be really very similar. It's just that 0:06:34.080 --> 0:06:37.640 you're generating them in a different way. So to us 0:06:37.680 --> 0:06:40.960 it sounds different, but the when you get down to 0:06:41.120 --> 0:06:45.160 like actually looking at wave forms, it would be very similar. Um. 0:06:45.279 --> 0:06:49.440 So these vibrations that we we are talking about, that's 0:06:49.480 --> 0:06:52.279 not It's not like something vibrates and then magically we 0:06:52.320 --> 0:06:55.400 can detect it. Other stuff has to happen for us 0:06:55.400 --> 0:06:59.040 to be able to perceive those vibrations. And generally what 0:06:59.040 --> 0:07:01.600 we're talking about is come pression and rare affection of 0:07:02.000 --> 0:07:06.440 air molecules. So, because as we've stated before, air is 0:07:06.480 --> 0:07:12.040 not empty, right, it is stuff, it's molecules. It's more 0:07:12.040 --> 0:07:13.760 like a soup. It's more like a soup that we 0:07:13.880 --> 0:07:16.240 just hang out in all the time. Yeah, it obeys 0:07:16.320 --> 0:07:20.560 the laws of fluid dynamics. Delicious nitrogen soup. Yeah. If 0:07:20.880 --> 0:07:23.560 there weren't that stuff, we would be in a vacuum 0:07:23.640 --> 0:07:26.520 and wouldn't be talking right now, because we'd be unable 0:07:26.560 --> 0:07:30.680 to generate sound or breathe. But you know sound on 0:07:30.760 --> 0:07:33.360 the same principle you've heard behind when you hear a 0:07:33.400 --> 0:07:36.080 nerd get mad that while in this movie something blew 0:07:36.160 --> 0:07:38.200 up in space and you heard it and you're not 0:07:38.320 --> 0:07:40.720 You really shouldn't be able to hear it. Yeah, if 0:07:40.760 --> 0:07:43.400 you were in the spacecraft, you would probably hear something. 0:07:43.920 --> 0:07:49.360 For all the air escaped. Every spaceship is miked extensively. Yeah, 0:07:49.880 --> 0:07:52.520 maybe it's and that's what the filmmakers are using. Yeah, 0:07:53.160 --> 0:07:56.760 it's just that whatever whatever space camera is on, that 0:07:56.880 --> 0:07:59.640 just automatically adds in the sound of an explosion, because 0:07:59.680 --> 0:08:02.559 otherwise is are a little tiny human brains would crack. Um. 0:08:02.760 --> 0:08:05.200 So when when the vibrations are moving, that causes the 0:08:05.240 --> 0:08:09.240 air molecules to move in this process of compression and rarefaction. 0:08:09.320 --> 0:08:12.120 That's essentially when air molecules are pressing together and then 0:08:12.160 --> 0:08:16.640 spreading apart again. Now that causes the adjacent air molecules 0:08:16.680 --> 0:08:18.440 to move, and so on and so forth until you 0:08:18.480 --> 0:08:22.240 go from the source of the sound to an ear drum. 0:08:22.280 --> 0:08:26.360 So when we're talking about the perception of sound, which 0:08:26.400 --> 0:08:30.360 from us, for we humans tends to be through hearing, 0:08:30.440 --> 0:08:33.480 but you can actually receive sound also through you know, 0:08:33.520 --> 0:08:36.960 you could have a tactile sensation, you could feel sound. 0:08:37.559 --> 0:08:40.280 But when we're talking about hearing, those air molecules end 0:08:40.360 --> 0:08:43.720 up impacting our ear drums. Now, our ear drums are 0:08:43.720 --> 0:08:46.080 really important. And it's a membrane that's attached to a 0:08:46.120 --> 0:08:48.640 series of three small bones that are in our middle 0:08:48.679 --> 0:08:52.600 ear that act as an amplifier. So your ear drums 0:08:52.600 --> 0:08:56.040 starts to vibrate, these three small bones essentially amplify that 0:08:56.559 --> 0:09:00.800 and they end up transmitting those vibrations to are to 0:09:00.960 --> 0:09:04.120 the cochlea which has this fluid in it and little 0:09:04.240 --> 0:09:09.120 tiny read like uh fibers, I guess you could say. Yeah. 0:09:09.720 --> 0:09:12.360 And those hair quot marks in the air, they're we're 0:09:12.480 --> 0:09:18.080 really useful on audio. And those hairs have specific resonant frequencies. 0:09:18.559 --> 0:09:22.280 So certain hairs will start to vibrate depending upon the 0:09:22.280 --> 0:09:25.800 motion of the fluid, and other other hairs won't vibrate 0:09:25.800 --> 0:09:29.600 because the resonance won't match up, you know, the rather, 0:09:29.679 --> 0:09:33.000 the vibrations won't match up with their particular resonance, right, 0:09:33.080 --> 0:09:36.680 And so the the hairs when they vibrate will send 0:09:36.880 --> 0:09:40.440 a signal like like pop off a little neuron to 0:09:40.559 --> 0:09:43.920 your brain saying like, hey, this hair vibrated, and your 0:09:43.960 --> 0:09:48.280 brain amasses all of those signals from those hairs to say, oh, 0:09:48.320 --> 0:09:50.560 this is what this thing sounds like. Right, So the 0:09:50.640 --> 0:09:52.960 sound you are hearing right now as you listen to 0:09:52.960 --> 0:09:58.280 this podcast is actually your brain interpreting those little vibrations 0:09:58.320 --> 0:10:02.439 of reads and then sending little electrical impulses and then 0:10:02.480 --> 0:10:05.080 there you go. So it's kind of cool and weird 0:10:05.240 --> 0:10:07.800 also in a way to think like, oh, sound is 0:10:07.840 --> 0:10:11.000 something that largely is happening inside my head. Like I 0:10:11.200 --> 0:10:14.960 know that there actually is a physical manifestation of sound 0:10:15.400 --> 0:10:18.560 because we have but but but ultimately our perception is 0:10:18.559 --> 0:10:20.720 all in the head. It's not like if you take 0:10:20.760 --> 0:10:24.080 the brain out that, uh you know, what would that 0:10:24.120 --> 0:10:27.560 sound be like without that particular process. Who can say 0:10:27.679 --> 0:10:31.160 that's not how we are, Like all reality is like 0:10:31.200 --> 0:10:35.800 a dream man. Yeah, Yeah, that's toads where I was 0:10:35.840 --> 0:10:40.400 going with that. So when we talk about about actually 0:10:40.440 --> 0:10:43.480 measuring sound, there are three things we typically look at, 0:10:43.480 --> 0:10:46.080 which are the frequency of the sound, the amplitude of 0:10:46.120 --> 0:10:48.720 that sound, and the wavelength of the sound wave. Yeah, 0:10:48.720 --> 0:10:50.600 and one thing that makes this kind of difficult with 0:10:50.720 --> 0:10:54.480 sound is that you usually picture these three variables in 0:10:54.600 --> 0:10:58.800 terms of a transverse wave like light or like the 0:10:58.920 --> 0:11:02.360 waves in the ocean shan, where the oscillation of the 0:11:02.360 --> 0:11:06.280 wave is moving perpendicular to the motion of the wave. 0:11:06.840 --> 0:11:09.200 So like you've often seen a picture of a wave, 0:11:09.280 --> 0:11:13.400 it's little hoops going up and down along a central midpoint, 0:11:13.840 --> 0:11:16.920 and sound is sort of the exception to that type 0:11:16.920 --> 0:11:19.079 of wave of motion. It's not really like that. It's 0:11:19.120 --> 0:11:22.280 a compression wave. It radiates outward from the source of 0:11:22.280 --> 0:11:26.439 the sound as well, so the oscillation is going parallel 0:11:26.520 --> 0:11:29.240 to the direction of the way right, and it's three dimensional, 0:11:30.360 --> 0:11:33.840 But we do use that two dimensional representation of waves 0:11:33.880 --> 0:11:39.120 to to look at sound waves because tiny delicate human brains. Yeah, 0:11:39.160 --> 0:11:42.960 it's way easier, it's useful. Yeah, it ends up being 0:11:43.040 --> 0:11:47.079 a useful way to describe the behavior of the sound waves. 0:11:47.120 --> 0:11:50.520 And it's not that the like technically you could say 0:11:50.559 --> 0:11:52.840 the depiction is not truly correct in the sense of 0:11:52.880 --> 0:11:55.319 the way the waves behave, but it ends up being 0:11:55.440 --> 0:11:59.760 useful for talking about things like um in versus, like 0:11:59.800 --> 0:12:03.240 an inverted sound wave, and uh, you know, when you 0:12:03.280 --> 0:12:06.840 pair it with the original sound wave what happens. Uh. So, 0:12:06.960 --> 0:12:12.600 frequency is what we would normally associate with pitch, right, technically, 0:12:13.160 --> 0:12:15.439 I mean it's it's this is the easiest way of 0:12:15.480 --> 0:12:17.640 saying it. The higher the frequency, the higher the pitch. Now, 0:12:17.720 --> 0:12:23.840 human hearing has a range of frequencies that typically we 0:12:23.920 --> 0:12:27.480 can detect. Now, this is typical in the sense that 0:12:27.559 --> 0:12:30.559 there are people who have a hearing range that can 0:12:30.600 --> 0:12:33.400 go a little further outside of it, and there's some 0:12:33.440 --> 0:12:37.760 people who it's narrower and um, typically we talk about 0:12:37.800 --> 0:12:41.760 it being from twenty hurts, which is twenty cycles per second. 0:12:42.840 --> 0:12:45.520 So that would be the frequency of you know, when 0:12:45.559 --> 0:12:49.160 these waves would pass. Uh, twenty of those cycles in 0:12:49.200 --> 0:12:51.760 the second would be one hurt or twenty hurts rather 0:12:52.320 --> 0:12:55.559 or up to twenty killer hurts, which is twenty thousand 0:12:55.720 --> 0:13:00.640 cycles per second. Uh. Again, that's a general rule of thumb. 0:13:01.640 --> 0:13:03.920 Some humans can hear outside of those ranges, and some 0:13:04.000 --> 0:13:08.560 are are are limited to a much narrower range. And 0:13:08.559 --> 0:13:12.760 and really the range that we hear best in is 0:13:12.880 --> 0:13:16.080 one killer hurts to about four killer hurts. Yeah, that 0:13:16.080 --> 0:13:19.600 that tends to be the range we mostly encounter. And 0:13:19.720 --> 0:13:22.920 are you know, like the range of human voices. It's 0:13:22.960 --> 0:13:26.080 what we work in daily. Yeah, what is the singular 0:13:26.080 --> 0:13:29.240 of killer hurts. It wouldn't be kill a hurt It's 0:13:29.920 --> 0:13:33.760 it's still hurt hurts because hurts is named after Hurts 0:13:33.840 --> 0:13:37.600 named after a person. But you don't say hurts is right, Yeah, 0:13:37.640 --> 0:13:41.319 it's it's four killer hurts is. It's like, dear, I'm 0:13:41.320 --> 0:13:44.439 going to start saying that from now on, you're being 0:13:44.520 --> 0:13:48.439 kill a hurtful all right? Anyway, moving on, always say 0:13:48.480 --> 0:13:53.000 it at one hurts all right. Now, obviously, you can 0:13:53.040 --> 0:13:55.760 have frequencies outside the range of human hearing, and these 0:13:55.760 --> 0:13:59.240 frequencies can still have a physical effect, and we will 0:13:59.280 --> 0:14:02.440 talk about any of those when we get into the 0:14:02.520 --> 0:14:04.960 future uses of sound. Yeah. In fact, a lot of 0:14:04.960 --> 0:14:08.960 times we specifically want to use frequencies of sound outside 0:14:09.000 --> 0:14:11.120 the range of human hearing. Yeah, because if you're using 0:14:11.160 --> 0:14:12.959 it within the range of human hearing, it could be 0:14:13.120 --> 0:14:17.400 really irritating depending upon the application. Right. Uh So, next 0:14:17.440 --> 0:14:21.080 we have the amplitude. So if you picture the transverse wave, 0:14:21.200 --> 0:14:23.320 right we were talking about, that's going to be the 0:14:23.400 --> 0:14:26.880 distance between the midpoint and the crest or the trough 0:14:26.920 --> 0:14:31.200 of the wave, and uh, amplitude essentially ends up being 0:14:31.520 --> 0:14:34.560 perceived as volume. So the greater the amplitude, the louder 0:14:34.640 --> 0:14:38.320 the sound. So your your frequency determines the pitch, the 0:14:38.320 --> 0:14:41.160 amplitude determines the volume. Then you have wavelength. This is 0:14:41.200 --> 0:14:45.360 the distance between two analogous points on two successive waves. 0:14:45.440 --> 0:14:47.840 So you pick a point on one wave, you pick 0:14:48.000 --> 0:14:50.520 essentially the same point on the next wave, and you 0:14:50.560 --> 0:14:53.160 measure the distance between the two. That is the wavelength 0:14:53.360 --> 0:14:56.080 of the sound wave. Very often you could just say 0:14:56.120 --> 0:15:01.040 it's crest to crest, right. So this depends upon the 0:15:01.120 --> 0:15:04.480 frequency and the medium through which the sound is traveling. 0:15:04.800 --> 0:15:08.640 Wavelength can vary even within the air, again, depending upon 0:15:08.680 --> 0:15:11.120 that temperature of the air or the humidity or the 0:15:11.200 --> 0:15:15.560 density of the air. Um and wavelength of frequency are 0:15:15.640 --> 0:15:19.240 inversely proportional to one another, So if the wavelength of 0:15:19.240 --> 0:15:23.440 a sound wave increases in uniform medium, the frequency decreases. 0:15:24.120 --> 0:15:26.840 So uh, this is important when you're starting to figure 0:15:26.840 --> 0:15:29.840 out things like the speed of sound through any given medium. 0:15:30.320 --> 0:15:32.240 If you know the frequency and you know the wavelength, 0:15:32.320 --> 0:15:34.040 then you multiply the two together and you get the 0:15:34.040 --> 0:15:36.760 speed of sound. And it also comes into effect when 0:15:36.760 --> 0:15:41.080 we're studying things like the Doppler effect, where the extension 0:15:41.200 --> 0:15:45.240 or the compression of waves can affect the frequency right. Uh. Now, 0:15:45.440 --> 0:15:47.720 we also need to talk about how sound waves can 0:15:47.720 --> 0:15:50.280 interact with each other because they could do some pretty 0:15:50.360 --> 0:15:54.440 interesting things. If you get two identical sound waves played together, 0:15:54.480 --> 0:15:57.040 they can amplify one another, so their amplitude can be 0:15:57.600 --> 0:16:00.840 uh additive. If you end up getting a sound wave 0:16:00.920 --> 0:16:04.280 where it encounters its inverse, they cancel each other out. 0:16:04.600 --> 0:16:07.760 This is the way noise canceling headphones work. They attempt 0:16:07.880 --> 0:16:11.280 to create an inverse wave that would end up canceling 0:16:11.280 --> 0:16:13.680 out all the noise that's around you, creating like a 0:16:13.680 --> 0:16:18.120 little pocket of of dead sound air. Yeah, that's the 0:16:18.280 --> 0:16:22.320 goal if they if they are working properly, Um, you 0:16:22.400 --> 0:16:25.120 know your your mileage may vary depending upon the sound 0:16:25.200 --> 0:16:29.640 canceling headphones. Uh. And two different sound waves that mixed 0:16:29.680 --> 0:16:31.720 together end up creating like if you were to look 0:16:31.760 --> 0:16:34.240 at this this depiction of a sound wave, it would 0:16:34.280 --> 0:16:38.000 end up looking really super funky because the the the 0:16:38.120 --> 0:16:40.480 troughs and crests would be affected by each other and 0:16:40.520 --> 0:16:44.200 you would end up getting a result where if one 0:16:44.280 --> 0:16:46.080 had a bit of a crest but the other one 0:16:46.120 --> 0:16:48.760 had a deeper trough, then it's gonna look like, well, 0:16:48.800 --> 0:16:50.800 now the new sound wave has a trough, but it's 0:16:50.800 --> 0:16:55.600 not as deep as from two. Very complex and mathematical 0:16:55.800 --> 0:16:58.240 and and actually I would totally love to have like 0:16:58.320 --> 0:17:01.800 a like a sound engineer come on the show and 0:17:01.840 --> 0:17:04.880 talk about it, because it is whoa like like way. 0:17:04.880 --> 0:17:06.520 Every time I start thinking about it, my brain just 0:17:06.560 --> 0:17:09.680 kind of goes It's it's also way easier to explain 0:17:09.720 --> 0:17:13.560 if you have the the visual aids of nearby, and 0:17:13.600 --> 0:17:16.479 then we do not obviously as an audio podcast. So 0:17:16.680 --> 0:17:19.000 and it's kind of funny that you need visual aids 0:17:19.040 --> 0:17:22.399 to explain sound that that is a rather amusing a 0:17:22.800 --> 0:17:25.080 little I mean, it's I guess it's a less more 0:17:25.119 --> 0:17:28.560 set version of ironic, don't you think. One more interesting 0:17:28.600 --> 0:17:31.159 things sound waves can do when interacting with each other is, 0:17:31.400 --> 0:17:35.280 for example, if you create an interference pattern with the 0:17:35.359 --> 0:17:38.280 sound wave and its reflection of itself off of a 0:17:38.320 --> 0:17:42.639 hard surface, you can create a standing wave sound. And 0:17:42.680 --> 0:17:45.040 we'll talk about those in a bit too. Yeah, that 0:17:45.160 --> 0:17:47.159 they come into use in some of the technology, but 0:17:47.480 --> 0:17:51.240 standing waves are a fascinating thing that can happen with 0:17:51.280 --> 0:17:54.680 all kinds of wave phenomena in nature, which is Yeah, 0:17:54.720 --> 0:17:59.800 one of those things that that or might seem counterintuitive 0:17:59.840 --> 0:18:03.000 at first when you think about like, well, how could 0:18:03.160 --> 0:18:06.240 how could sound do this thing? But as you learn 0:18:06.280 --> 0:18:08.680 more and more health sound works, it starts to make sense. 0:18:08.680 --> 0:18:12.840 It's just based upon what what we can directly observe 0:18:12.880 --> 0:18:15.879 in our day to day lives. It seems really like, wow, 0:18:15.920 --> 0:18:20.160 that's magic. Yeah, yeah, although it's not. I mean at 0:18:20.160 --> 0:18:24.240 a at a more macro level, we've all experienced a 0:18:24.280 --> 0:18:28.360 sonic boom, right, and and so we have some kind 0:18:28.359 --> 0:18:31.880 of experience with what sound is this physical force? Right 0:18:31.960 --> 0:18:34.440 that shows that this isn't just all in your head. 0:18:34.520 --> 0:18:36.880 Even though the perception of sound maybe in your head, 0:18:37.000 --> 0:18:40.000 there's the you can physically feel sound like from a 0:18:40.000 --> 0:18:43.200 sonic boom. You can feel that shock wave hit um 0:18:43.600 --> 0:18:46.199 and uh. You know this is something where it's that 0:18:46.359 --> 0:18:49.840 compression and rare affaction. You can't get that wave coming 0:18:49.840 --> 0:18:53.560 out from a big event like a sonic boom. It 0:18:53.600 --> 0:18:57.159 can do some damage, like remember when the meteorite passed 0:18:57.160 --> 0:19:00.720 overhead of in various aerias in Rush, where there were 0:19:00.760 --> 0:19:03.480 towns that were reporting that there were entire buildings that 0:19:03.520 --> 0:19:06.639 add a face of the wall, all the glass just 0:19:06.800 --> 0:19:11.879 shattering because that that pressure wave was so powerful. So 0:19:11.880 --> 0:19:16.760 sound is definitely something that can have a big impact, 0:19:16.920 --> 0:19:19.840 literally a big impact. Now, we talked a little bit 0:19:19.840 --> 0:19:21.960 about the speed of sound. That sound travels at a 0:19:22.040 --> 0:19:25.800 uniform speed depending upon the medium through which it travels. 0:19:26.200 --> 0:19:29.880 So if you want sound to travel faster or slower, 0:19:30.640 --> 0:19:32.800 really all you can do is affect the medium. You 0:19:32.840 --> 0:19:35.480 can either transition it from one medium to another, or 0:19:35.640 --> 0:19:38.800 you affect that those physical parameters of the medium. You 0:19:38.920 --> 0:19:42.960 can't do it by increasing the frequency or the wavelength 0:19:42.960 --> 0:19:45.280 because if you if you make the frequency, if you 0:19:45.320 --> 0:19:49.159 increase the frequency, the wavelength will decrease because they're inversely proportional. 0:19:49.600 --> 0:19:53.120 If you increase the wavelength, then the frequency will decrease 0:19:53.200 --> 0:19:55.760 again inversely proportional. So the only way you can make 0:19:55.800 --> 0:19:58.400 the sound travel at a different speed, because remember that's 0:19:58.440 --> 0:20:01.639 the product of wavelength and frequency, The only way you 0:20:01.680 --> 0:20:03.879 can make the sound travel at a different speed is 0:20:03.920 --> 0:20:08.239 to change the medium in some way. So that's kind 0:20:08.280 --> 0:20:11.840 of interesting too. Now that might mean transferring it from 0:20:11.840 --> 0:20:14.880 one medium to another, like a solid to a gas, 0:20:15.359 --> 0:20:18.760 or one liquid to another liquid, or anything along those lines, 0:20:18.840 --> 0:20:21.840 or it might mean that you physically change the medium 0:20:21.880 --> 0:20:24.760 in some way, um you create you know, like if 0:20:24.800 --> 0:20:27.640 you increase the tension on a drumhead, technically you're stretching 0:20:27.880 --> 0:20:33.280 everything out. That changes the nature of that matter. So, uh, 0:20:33.400 --> 0:20:36.280 that is important to remember as well, because knowing that 0:20:37.000 --> 0:20:39.359 the sound of the speed of sound is going to 0:20:39.400 --> 0:20:43.280 be constant gives us lots of opportunities to use sound 0:20:43.440 --> 0:20:47.320 in super cool ways. Right Yeah, what once you once 0:20:47.359 --> 0:20:51.320 you batten down a single variable in a scientific experiment, 0:20:51.359 --> 0:20:53.359 of course, that gives you a lot of opportunity to 0:20:53.440 --> 0:20:56.119 play with the others, right, right. So one of the 0:20:56.119 --> 0:20:58.840 ways that people are going to be most familiar with 0:20:59.040 --> 0:21:03.600 using sound as a sort of like novel technological tool 0:21:04.160 --> 0:21:06.840 will be in medicine. Yes, I mean many people have 0:21:06.960 --> 0:21:11.960 themselves undergone an ultrasound right yeah, yeah, it's pretty common. Yeah, 0:21:11.960 --> 0:21:14.840 it's very common. So you can have like ultrasound imaging 0:21:15.280 --> 0:21:17.359 as a way of like getting a look at what's 0:21:17.359 --> 0:21:19.720 inside your body. A lot of times this will be 0:21:19.760 --> 0:21:22.959 done during a pregnancy or to try to diagnose you know, 0:21:23.720 --> 0:21:26.800 gall bladder stones or any kind of thing like that, 0:21:27.240 --> 0:21:29.280 or you could use it as a tool, say to 0:21:29.680 --> 0:21:34.560 for example, dissolve kidney stones. But there are lots of 0:21:34.600 --> 0:21:37.800 new ways that people might be using ultrasound in medicine, 0:21:38.160 --> 0:21:45.439 for example, even in diagnosing cancer. Yeah, and actually ultrasound 0:21:45.640 --> 0:21:48.840 is currently being used in diagnosing cancer. I'm going to 0:21:48.920 --> 0:21:51.240 talk about a super fancy sound method in a minute, 0:21:51.240 --> 0:21:53.959 but let's let's talk about this ultrasound specifically as it 0:21:54.000 --> 0:21:57.719 relates to cancer, because it is so fascinating to me. Okay, 0:21:57.800 --> 0:22:01.480 So various imaging method these days are used to screen 0:22:01.560 --> 0:22:04.320 for tumors within a patient's body, And it's pretty cool 0:22:04.359 --> 0:22:08.080 that we have imaging methods because, uh, they're really good 0:22:08.080 --> 0:22:11.120 at detecting cancer in its early stages before it's done 0:22:11.160 --> 0:22:13.960 too much damage. They're all pretty new. Like previous to 0:22:13.960 --> 0:22:17.359 the late nineteen sixties, tumors were basically discovered by either 0:22:17.480 --> 0:22:21.000 looking at them or poking them, and that's almost the 0:22:21.000 --> 0:22:25.479 technical term really, or just like waiting until the patient 0:22:25.560 --> 0:22:27.439 symptoms developed to the point that a doctor thought it 0:22:27.480 --> 0:22:30.240 was worthwhile to cut them open and see what was 0:22:30.320 --> 0:22:33.240 going on. And that's the other way in which imaging 0:22:33.320 --> 0:22:35.560 is cool, of course, as a screening method, because most 0:22:35.560 --> 0:22:39.040 forms of it are pretty safe and non invasive. From 0:22:39.200 --> 0:22:41.840 the nineteen twenties to the nineteen sixties, a few tests 0:22:41.840 --> 0:22:44.840 were developed that could detect cancerous or pre cancerous cells 0:22:44.920 --> 0:22:48.480 from like membrane swabs or urine or fecal matter, but 0:22:48.520 --> 0:22:53.280 it wasn't until the late nineteen sixties that researchers developed mammography, 0:22:53.440 --> 0:22:56.199 which of course is a specialized X ray method for 0:22:56.320 --> 0:23:00.399 viewing breast tissue that became the first widely used imaging 0:23:00.400 --> 0:23:04.400 method for cancer. But in the early nineteen eighties, researchers 0:23:04.359 --> 0:23:09.919 began developing other imaging methods, starting with ultrasound. Uh yeah, 0:23:10.000 --> 0:23:13.040 so it was first used in the detection of prostate cancer, 0:23:13.119 --> 0:23:15.760 though it's since been found to be no more accurate 0:23:15.800 --> 0:23:20.840 than a classic touch based digital examination from a trained doctor, 0:23:22.160 --> 0:23:25.679