WEBVTT - A Series of Tubes Part One 0:00:04.240 --> 0:00:07.520 Get in touch with technology with text Stuff from stuff 0:00:07.800 --> 0:00:15.400 dot com. Welcome to text Stuff. I'm Jonathan Strickland. Man, 0:00:15.520 --> 0:00:18.840 I'm Laurence. Lauren has come back to talk with us 0:00:18.960 --> 0:00:22.119 about a subject you You wrote a script for a 0:00:22.560 --> 0:00:26.400 video series week Yeah, over on brain Stuff. I'm one 0:00:26.440 --> 0:00:32.000 of the writers, our illustrious writing the team's team of writers. 0:00:32.040 --> 0:00:34.440 They're they're amazing. They're the ones who make me sound 0:00:34.440 --> 0:00:39.280 good as otherwise I sound like this. No, you make 0:00:39.360 --> 0:00:44.400 you sound good, thank you. But yeah, we decided to 0:00:44.440 --> 0:00:48.600 do an episode on pneumatics too. Yeah, and I was 0:00:48.640 --> 0:00:50.720 the one who wrote that thing, and I said, hey, 0:00:50.960 --> 0:00:54.040 this is a two minute video. Uh, this isn't really 0:00:54.080 --> 0:00:57.440 covering everything I think there is to say about pneumatic tubes. 0:00:57.880 --> 0:00:59.800 So Jonathan, why don't we do a tech stuff episode 0:00:59.800 --> 0:01:02.160 about right instead of a two minute video, We're going 0:01:02.200 --> 0:01:05.480 to make a two part episode because we have ten 0:01:05.560 --> 0:01:08.440 pages of notes. I think I think that that is 0:01:08.480 --> 0:01:12.000 officially the most notes we have ever compiled on anything, 0:01:12.040 --> 0:01:14.800 except for maybe D M C A or A T 0:01:14.959 --> 0:01:18.120 and T or one of those big like three parts. Yeah. Yeah, 0:01:18.160 --> 0:01:21.759 those those definitely get pretty intense. But it was interesting 0:01:21.800 --> 0:01:25.200 that we can actually because you think pneumatic tubes, especially 0:01:25.200 --> 0:01:29.399 people who have have had any kind of uh interaction 0:01:29.440 --> 0:01:32.280 with these, like a drive through bank teller type thing, 0:01:33.280 --> 0:01:38.000 You wouldn't think that would necessarily end up being Yeah, 0:01:38.040 --> 0:01:42.080 but as it turns out, one, it's super cool. I'm fascinating, Yes, 0:01:42.319 --> 0:01:47.120 and to it there's a rich history, oh yeah, of 0:01:47.319 --> 0:01:50.120 being used in lots of different ways. So one of 0:01:50.120 --> 0:01:54.000 the cool things that you brought to light is that, uh, 0:01:54.040 --> 0:01:57.040 you know that these are not just little systems that 0:01:57.080 --> 0:02:00.680 are used within like that bank that drive a single 0:02:00.800 --> 0:02:03.880 building to take your bank receipt to the teller when 0:02:03.880 --> 0:02:05.760 you don't feel like getting out of your car, right, 0:02:05.880 --> 0:02:08.880 That these actually used to be and in some cases 0:02:08.919 --> 0:02:13.160 maybe still are much more extensive. Yeah. See, there used 0:02:13.200 --> 0:02:16.560 to be these huge networks of tubes buried beneath the 0:02:16.639 --> 0:02:19.440 cities that let people send messages to each other faster 0:02:19.560 --> 0:02:25.640 than ever before. Yeah, I've heard of this the Internet. 0:02:25.720 --> 0:02:28.880 It's a it's a series of tubes. Uh no, No, 0:02:29.000 --> 0:02:32.360 before before the Internet are pannet but that was only 0:02:32.400 --> 0:02:37.040 like three computers and it was it was wow. Yeah, 0:02:37.240 --> 0:02:40.639 pneumatic tubes date back quite a ways. And so yeah, 0:02:40.639 --> 0:02:42.800 when when Lauren said, we're going to talk about a 0:02:42.840 --> 0:02:44.480 series of tubes. I thought we were going to talk 0:02:44.520 --> 0:02:47.560 about the whole you know, good old Senator Ted from 0:02:47.560 --> 0:02:50.359 Alaska talking about how the Internet is a series of tubes, which, 0:02:50.400 --> 0:02:52.959 by the way, just for the record, I think is 0:02:53.000 --> 0:02:56.600 a decent analogy. Yeah, yeah, I mean it was. I mean, 0:02:56.639 --> 0:02:58.760 it is funny, but it was. And also, as it 0:02:58.760 --> 0:03:01.560 turns out, some telecom cables are currently being housed in 0:03:01.639 --> 0:03:07.480 old neumatic tubes, so it is yeah, awesome. So what 0:03:07.639 --> 0:03:11.360 exactly is a pneumatic tube. Well, it is a pipeline 0:03:11.360 --> 0:03:13.679 that uses air pressure to move a canister from one 0:03:13.680 --> 0:03:18.280 point to another. Okay, that seems pretty simple. So like 0:03:18.440 --> 0:03:22.720 it seems pretty simple, but wait, there's more, uh there? Yeah, 0:03:23.280 --> 0:03:25.560 I mean, these things have come a very long way 0:03:25.880 --> 0:03:31.000 as technology has advanced up. Motors have advanced. Motors started existing, 0:03:31.040 --> 0:03:33.799 Like like electricity wasn't really a thing when nematic tubes 0:03:34.200 --> 0:03:38.839 started up. Computers happened, right, And actually you might think, well, 0:03:38.840 --> 0:03:43.080 computers would end up, you know, making the whole purpose 0:03:43.200 --> 0:03:46.240 of these things obsolete, but that's not the case. In fact, 0:03:46.320 --> 0:03:51.080 there's still very high tech pneumatic tube systems that are 0:03:51.120 --> 0:03:54.880 at play in various locations for good reasons, And it 0:03:54.920 --> 0:03:57.600 turns out that the computers aren't necessary elements in that 0:03:57.640 --> 0:04:00.560 in order to be kind of like traffic control. So 0:04:00.920 --> 0:04:04.320 it's kind of cool that this thing that we would 0:04:04.520 --> 0:04:09.040 normally think was replaced by computers is actually complementing them 0:04:09.040 --> 0:04:12.040 in specific use cases. Obviously, if you want to send 0:04:12.040 --> 0:04:16.000 a message to your friend across town, you're more likely 0:04:16.080 --> 0:04:18.680 to either drop a letter in the mail or much 0:04:18.720 --> 0:04:25.400 more likely to send the message. But there are many 0:04:25.440 --> 0:04:29.480 important uses for pneumatic tubes. Um. We only get into 0:04:29.560 --> 0:04:33.520 many of those later. First, let us talk specifically about 0:04:33.560 --> 0:04:36.719 how pneumatic tubes work. Yeah, let's talk about the physics 0:04:36.800 --> 0:04:40.200 what is going on with a pneumatic tube? And so 0:04:40.600 --> 0:04:44.680 walk me through the you wrote. You've you've described an 0:04:44.760 --> 0:04:47.800 excellent way of thinking through this so that we have 0:04:47.839 --> 0:04:50.680 a logical progression to get to the actual mechanics of 0:04:50.720 --> 0:04:54.880 pneumatic tubes. Okay, So, pneumatic, in case you don't know, 0:04:55.160 --> 0:05:00.800 means works via pressurized gas. Basically, Um, So the air 0:05:00.839 --> 0:05:04.359 around us seems pretty thin, right, but it's actually a soup. 0:05:04.560 --> 0:05:07.440 It's actually a liquid made up of lightweight atoms and 0:05:07.560 --> 0:05:11.640 particles like nitrogen and oxygen and argon and carbon dioxide 0:05:11.640 --> 0:05:15.200 and ozone and dust bunnies and et cetera. Yeah, yeah, uh, 0:05:15.240 --> 0:05:18.520 And that soup is at pretty much constant density and 0:05:18.560 --> 0:05:21.800 pressure around us while we're walking around on Earth's surface, 0:05:22.080 --> 0:05:24.640 though it's a little bit thinner. The further away from 0:05:24.680 --> 0:05:27.240 sea level you get, right, Right, the higher you climb 0:05:27.240 --> 0:05:30.560 on a mountain, for example, the less dense the air. 0:05:30.760 --> 0:05:35.240 Thus you have let lower air pressure at those altitudes. Right. 0:05:35.279 --> 0:05:38.400 And it's useful to think about that because one great 0:05:38.440 --> 0:05:43.120 way of thinking about air pressure and how it helps 0:05:43.160 --> 0:05:45.640 stuff work is by thinking of how your ears pop 0:05:45.680 --> 0:05:48.200 when you go up in a really tall elevator or 0:05:48.560 --> 0:05:51.279 or up a mountain or up in an airplane. Um. 0:05:51.320 --> 0:05:54.360 And that's because your your ears pop because of the 0:05:54.640 --> 0:05:57.920 density of the air outside of your body being lower 0:05:57.960 --> 0:06:00.960 than the density of the air in your ears. Okay, 0:06:01.080 --> 0:06:04.279 You've got this little tube of air in your in 0:06:04.320 --> 0:06:08.080 your head called the station tube, and it lets your 0:06:08.160 --> 0:06:10.359 it lets your ear drum vibrate, which is important for 0:06:10.400 --> 0:06:13.080 your ear drum to function. Right. That's what allows you 0:06:13.120 --> 0:06:17.880 to interpret sound, right, because sound is a physical uh phenomenon. 0:06:18.000 --> 0:06:23.560 It vibrates the ear drum, which makes some celia go, well, yeah, 0:06:24.240 --> 0:06:28.440 that signals the brain that exactly. Yeah, we're just gonna 0:06:28.520 --> 0:06:31.760 re enact once more with feeling line by line, But no, 0:06:31.880 --> 0:06:34.599 it does. You know. The ear drum is what ends 0:06:34.680 --> 0:06:37.440 up causing these other bones in your in your ear 0:06:37.520 --> 0:06:40.440 to move in such a way that celia inside of 0:06:40.520 --> 0:06:44.880 this one container, uh, start to vibrate fluctuate, and that 0:06:44.920 --> 0:06:47.400 sends electrical signals to your brain, which then is interpreted 0:06:47.440 --> 0:06:51.600 as sound. So without that vibration, you don't hear, uh, 0:06:51.640 --> 0:06:54.400 And without this tube you wouldn't get that vibration. That 0:06:54.440 --> 0:06:56.479 would have nothing to vibrate against. It would just be 0:06:56.560 --> 0:07:00.640 all solid meat and that doesn't vibrate as well. Yeah, yeah, 0:07:00.680 --> 0:07:02.839 I mean sound can travel through solids, but it's not 0:07:02.880 --> 0:07:06.000 as effective going from air to solid then from solid 0:07:06.040 --> 0:07:08.880 to solid, so right, you know it's important. So the 0:07:08.960 --> 0:07:11.840 C station tube is shut off with muscles that are 0:07:11.880 --> 0:07:15.720 tied into your mouth, throat swallowing muscles. This is one 0:07:15.720 --> 0:07:17.480 of those things I always thought was weird that that 0:07:17.520 --> 0:07:20.640 our ears are connected to I mean, the human bodies 0:07:20.680 --> 0:07:25.280 gross y'all, especially the sinus type system. Yeah, and that's 0:07:25.320 --> 0:07:28.440 that's why if you swallow, you hear like a tiny 0:07:28.520 --> 0:07:31.840 little pop, and that is the muscles of that tube 0:07:31.880 --> 0:07:34.840 opening up and and letting a fresh supply of air in, 0:07:35.000 --> 0:07:37.280 which is important because the air that gets into the 0:07:37.320 --> 0:07:39.800 tube gets absorbed by the walls of the tube, and 0:07:39.840 --> 0:07:42.840 so it needs to be replenished periodically. That's also why 0:07:42.880 --> 0:07:45.480 your head hurts so much when when you have a cold, 0:07:45.600 --> 0:07:49.600 because those muscles get stuffed up by gunk and you 0:07:49.640 --> 0:07:52.400 can't replenish that air supply and everything hurt. When you're 0:07:52.480 --> 0:07:54.480 like I can't hear because I have a cold, it 0:07:54.520 --> 0:07:58.400 seems weird because yeah, yeah, that's because the because your 0:07:58.560 --> 0:08:01.040 ear drum literally cannot vibe rate because there's not a 0:08:01.080 --> 0:08:03.720 replenishment of air in the tube. That's kind of cool. 0:08:03.840 --> 0:08:05.840 I mean, I had never thought of it that way. 0:08:05.920 --> 0:08:09.040 So interesting. Okay, so all of this is a sidebar promise. 0:08:09.080 --> 0:08:12.600 We're getting back to neumatics. Um. So, so as you 0:08:12.640 --> 0:08:17.880 gain altitude, the air inside of your ears starts exerting 0:08:17.920 --> 0:08:22.720 pressure on those membranes. Um, it starts pushing because it's 0:08:22.760 --> 0:08:27.760 at that higher density than the air outside. Um. You know, 0:08:27.920 --> 0:08:31.240 it wants to be chill like that lower pressure air. 0:08:31.560 --> 0:08:35.080 You never let it hang loose. Yeah, when you create 0:08:35.120 --> 0:08:38.280 this pressure differential than there. That's where you're starting to 0:08:38.360 --> 0:08:41.400 get that feeling of something's just kind of like you 0:08:41.440 --> 0:08:44.840 get that ache. You can get pretty painful too, if 0:08:44.880 --> 0:08:47.880 you especially like you know, you hear about babies and 0:08:47.960 --> 0:08:51.120 kids having real problems because they haven't figured out how 0:08:51.160 --> 0:08:56.080 to voluntarily open up their irustration tube. Yeah. And so 0:08:56.480 --> 0:08:58.960 when the difference in pressure is great enough that you 0:08:59.040 --> 0:09:03.040 either volunteerly or involuntarily open up that illustration tube, that 0:09:03.120 --> 0:09:06.520 the sudden release of that pressurized air is pretty forceful 0:09:06.600 --> 0:09:11.000 and creates that pop. That's when your um But that 0:09:11.120 --> 0:09:14.880 is just one example of pressure at work around us. Uh. 0:09:14.920 --> 0:09:16.400 This next one that I've got for you is a 0:09:16.400 --> 0:09:19.480 little bit more technical. Are you ready? Yeah? Okay, straws 0:09:20.360 --> 0:09:24.040 like what the pig built his house out of drinking 0:09:24.080 --> 0:09:27.760 straw Okay, so crazy straws in my case, but yeah, 0:09:27.800 --> 0:09:31.720 sure sure, crazy straws totally. So you're not technically pulling 0:09:31.800 --> 0:09:35.559 liquid up through a straw. You're you're creating an opportunity 0:09:35.640 --> 0:09:39.400 for the liquid to push itself up. So I'm motivating 0:09:39.440 --> 0:09:42.199 the liquid that you're motivating the liquid. Yeah, exactly. The 0:09:42.800 --> 0:09:46.000 section that you apply with your mouth creates an area 0:09:46.080 --> 0:09:48.920 of low pressure at the top of the straw, which 0:09:49.000 --> 0:09:52.000 means that the relatively high pressure liquid at the bottom 0:09:52.040 --> 0:09:55.120 of the straw pushes a sip of your drink up 0:09:55.120 --> 0:09:58.040 into your mouth. Well, this is really interesting to me 0:09:58.200 --> 0:10:01.320 because I talked about a similar thing with Josh Clark 0:10:02.280 --> 0:10:05.120 when we covered how toilets work, because we had to 0:10:05.160 --> 0:10:09.720 talk about siphoning and the siphoning and uses a similar 0:10:09.760 --> 0:10:13.319 principle and it does require this difference in pressure as well. 0:10:13.679 --> 0:10:18.520 So very interesting. So how does this compared to say, 0:10:18.520 --> 0:10:22.360 pneumatic tubes. Well, it's it's basically the same thing. Um. 0:10:23.080 --> 0:10:25.679 The the tube part is air tight like a straw, 0:10:26.480 --> 0:10:29.400 except it has sealable hatches at either end instead of 0:10:29.440 --> 0:10:33.200 you know straw. Bit's yeah. Um, so so you you 0:10:33.240 --> 0:10:35.520 put a canister in one hatch. Yeah, it helps a 0:10:35.520 --> 0:10:37.160 whole lot off. The canister has some kind of like 0:10:37.200 --> 0:10:40.240 flexible skirts on either end, the concealed to the interior 0:10:40.320 --> 0:10:43.040 edges of the tube. That air is not passing around 0:10:43.200 --> 0:10:46.400 around the canister right to make it the most effective. 0:10:46.840 --> 0:10:48.680 So you so you put your canister in there, you 0:10:48.720 --> 0:10:51.920 close the hatch, and you press your go button. Um. Now, 0:10:51.960 --> 0:10:54.120 on the other end of the tube, pressing that button 0:10:54.160 --> 0:10:57.440 will open up a vent and start a motor. Now 0:10:58.080 --> 0:10:59.920 one of two things will happen at this point, right, 0:11:00.200 --> 0:11:03.120 So this all depends upon where the canister is in 0:11:03.200 --> 0:11:06.400 relation to where the blower is. So here's the boring one, 0:11:06.720 --> 0:11:08.720 because because you get to take the really cool one. 0:11:08.760 --> 0:11:11.040 Here's the boring one if the canister is on the 0:11:11.040 --> 0:11:13.760 blower side. So in other words, this is like the 0:11:14.559 --> 0:11:17.920 blower being a fan essentially that can either blow air 0:11:18.000 --> 0:11:20.600 into the tube or pull air out of the tube 0:11:20.840 --> 0:11:22.760 if it's on the blower side, and the only way 0:11:22.760 --> 0:11:24.160 to move the canister to the other end of the 0:11:24.200 --> 0:11:27.560 tube is to blow air against the canister pushing it, 0:11:27.600 --> 0:11:30.640 so you're increasing the air pressure on the side of 0:11:30.679 --> 0:11:34.360 the blower and it just blows the canister across. So 0:11:34.400 --> 0:11:36.560 this is essentially the same as when you shoot blow 0:11:36.640 --> 0:11:40.160 darts at your coworkers, or when I say you when 0:11:40.200 --> 0:11:43.719 I shoot blow darts at Ben bowling, Um, he has 0:11:43.760 --> 0:11:46.679 wondered what that tingling sensation has been and no one 0:11:46.760 --> 0:11:50.719 tell him. But that's essentially it. So yeah, but if 0:11:50.720 --> 0:11:53.120 the canisters on the opposite side, see, the blower on 0:11:53.160 --> 0:11:56.520 a pneumatic tube system typically is at just one end. 0:11:56.600 --> 0:11:59.440 You don't have two blowers right right, And it's not um. 0:12:00.640 --> 0:12:04.479 Especially classically, these things weren't always powerful enough to necessarily 0:12:04.600 --> 0:12:08.360 push at right. So if the canisters on the opposite end, 0:12:08.840 --> 0:12:11.640 like I, I've sent something out now, I'm expecting it 0:12:11.720 --> 0:12:14.839 to come back, but my blower is at the the 0:12:14.960 --> 0:12:17.200 end where I am at, I have to I have 0:12:17.280 --> 0:12:19.200 to find a different way to move the canster. I 0:12:19.240 --> 0:12:21.840 can't push it by by turning the fan to blow 0:12:21.880 --> 0:12:24.839 air into the tube. So what do I do then? Well, 0:12:25.080 --> 0:12:28.480 the motor will still drive a fan down at the 0:12:28.480 --> 0:12:31.480 other end of the tube, but but this time it 0:12:31.520 --> 0:12:35.400 will start to pull air out of the tube, venting 0:12:35.440 --> 0:12:38.760 it out of the tube entirely. Got okay, This section, 0:12:39.320 --> 0:12:42.520 just like a straw, creates a partial vacuum at that 0:12:42.640 --> 0:12:44.760 end of the tube with the fan an area of 0:12:44.880 --> 0:12:48.960 low pressure. So uh, you know, down down at the 0:12:49.040 --> 0:12:52.600 canister end of the tube, the higher pressure air behind 0:12:52.760 --> 0:12:57.000 the canister wants to expand to settle the difference, right, um, 0:12:57.280 --> 0:13:00.240 So it will push the canister through the two So 0:13:00.280 --> 0:13:02.839 the cancer is still being pushed. It's just that it's 0:13:02.840 --> 0:13:05.480 being pushed because the air behind it is at a 0:13:05.559 --> 0:13:08.000 higher pressure. Than the air in front of it, exactly. 0:13:08.280 --> 0:13:11.080 It's so cool. So in most of these systems, when 0:13:11.120 --> 0:13:14.520 the canister reaches its destination um like the end of 0:13:14.559 --> 0:13:17.480 the tube, it will trigger a trapdoor to close behind it, 0:13:17.559 --> 0:13:19.880 which will also que the motor to turn off end 0:13:19.960 --> 0:13:23.280 the vnced close, meaning that the partial vacuum that's been 0:13:23.280 --> 0:13:26.199 created in the tube will be broken and your buddy 0:13:26.240 --> 0:13:28.120 at the other end can open up the hatch and 0:13:28.280 --> 0:13:30.640 take out the canister. And that makes perfect sense because 0:13:30.640 --> 0:13:33.800 obviously if you had continue to have that vacuum they're 0:13:33.920 --> 0:13:36.760 opening up the hatch would have been difficult, it real hard, yeah, 0:13:37.080 --> 0:13:39.440 because that that air pressure on the outside of the 0:13:39.480 --> 0:13:42.040 tube is pushing against it. You know. It's this same 0:13:42.080 --> 0:13:43.920 sort of deal. That's just one of those things that 0:13:44.160 --> 0:13:46.720 you have to have all the lower parts in place 0:13:46.760 --> 0:13:49.400 for the system to work properly. And the big advantage 0:13:49.400 --> 0:13:51.560 of this sort of system is that you don't have 0:13:51.600 --> 0:13:54.480 to connect little motors to all those canisters, right. The 0:13:54.520 --> 0:13:58.120 individual units don't need anything, they don't need any moving parts. Yeah, 0:13:58.200 --> 0:14:00.680 the whole the system is a whole can have a 0:14:00.760 --> 0:14:03.199 single well, it can have a single motor. A lot 0:14:03.200 --> 0:14:05.960 of the time these days they've got really complex multiple 0:14:06.040 --> 0:14:09.760 motor things going on, especially if you have like lots 0:14:09.800 --> 0:14:13.559 of potential destinations. But but if you had a very 0:14:13.559 --> 0:14:15.440 simple system where it was just an out and back, 0:14:15.800 --> 0:14:19.200 you would just need one one motor turning one fan 0:14:19.600 --> 0:14:21.800 or or you know, some people just refer to him 0:14:21.840 --> 0:14:26.960 as air compressors, but technically you're using a fan anything fan. Yeah. So, yeah, 0:14:27.000 --> 0:14:32.280 that's really interesting. And there are also some interesting advantages 0:14:32.360 --> 0:14:36.560 or rather design elements that have been made to make 0:14:36.600 --> 0:14:40.480 sure that the canisters arrived safely, right, because in the 0:14:40.520 --> 0:14:45.040 original systems, canisters would arrive by basically just crashing into 0:14:45.040 --> 0:14:47.280 the opposite end of the two Yeah, they and they 0:14:47.280 --> 0:14:50.360 could be going pretty darn fast, depending on how powerful 0:14:50.440 --> 0:14:53.280 that fan was. Yeah, tens of miles an hour, which 0:14:53.440 --> 0:14:55.640 which I mean usually I say is kind of a joke, 0:14:55.720 --> 0:14:58.400 but actually that's pretty quick, Yeah, especially for something like 0:14:58.440 --> 0:15:00.680 if you haven't designed it just right, it's gonna you know, 0:15:00.760 --> 0:15:03.240 just just smash it up, yeah, or it's gonna end 0:15:03.280 --> 0:15:06.000 up causing damage to the tubes. And obviously that's a problem. 0:15:06.040 --> 0:15:09.040 So there are a couple of different ways of slowing 0:15:09.040 --> 0:15:12.400 them down properly. One of those uses air brakes, which 0:15:12.400 --> 0:15:15.440 is essentially just again pressurized air, but now on the 0:15:15.520 --> 0:15:18.440 low pressure side, so that can slow down the canister 0:15:18.560 --> 0:15:22.720 from you know, it's it's inevitable crash towards oblivion, or 0:15:23.200 --> 0:15:26.560 bumpers like little rubber bumpers that can come out from 0:15:26.600 --> 0:15:29.080 the sides to slow like the way a lot of 0:15:29.920 --> 0:15:34.080 roller coaster brakes work. Huh. And also they often have 0:15:34.240 --> 0:15:37.400 some form of switch that once a castor passes that switch, 0:15:37.720 --> 0:15:41.280 it activates it, which then turns off power to the blower. Uh. Now, 0:15:41.320 --> 0:15:44.520 momentum still a thing, so you have to plan for 0:15:44.600 --> 0:15:47.680 that as well. But yeah, yeah, it's sort of like 0:15:47.720 --> 0:15:50.240 the trapdoor idea, but with a little bit of a 0:15:50.320 --> 0:15:54.640 longer glide after the trapdoor. Right, So now I'm going 0:15:54.680 --> 0:15:59.320 to try and explain without the use of visual aids, 0:16:00.040 --> 0:16:03.840 how how a simple pneumatic tube system using a couple 0:16:03.880 --> 0:16:07.920 of valves and a switch would help a canister come 0:16:07.960 --> 0:16:12.080 to a stop. All right, So, uh, you've got with 0:16:12.120 --> 0:16:14.680 the two valves. These create a pathway for air in 0:16:14.720 --> 0:16:17.600 front of the canister to vent out for most of 0:16:17.600 --> 0:16:19.640 the trip, while leaving enough for the very end to 0:16:19.640 --> 0:16:21.960 act as a cushion. So in other words, you need 0:16:22.000 --> 0:16:24.760 a way for air to vent outward or else you'll 0:16:24.800 --> 0:16:27.240 never create that area of low pressure. But you need 0:16:27.280 --> 0:16:28.920 a way to keep a little bit of air in 0:16:28.960 --> 0:16:31.240 there so that it can act as a breaking system. 0:16:31.880 --> 0:16:33.600 So you've got to figure out how to do that. 0:16:33.680 --> 0:16:37.520 And when I saw there was a a series of 0:16:37.600 --> 0:16:41.600 illustrations I saw online that explained this really well. And 0:16:41.840 --> 0:16:44.440 uh so I'm going to try and walk you through 0:16:44.480 --> 0:16:47.280 it the best way I know how. So we're playing 0:16:47.320 --> 0:16:50.720 Dungeons and Dragons, y'all, and here's here's what's happening. So 0:16:50.760 --> 0:16:55.640 your adventurer is in a tunnel and behind you as 0:16:55.680 --> 0:16:59.000 a giant spinning fan of death. Oh yeah, I think 0:16:59.000 --> 0:17:02.120 I've been on this module before. Okay, So in this case, 0:17:02.200 --> 0:17:05.200 the giant spinning fan of death is currently slow. It's 0:17:05.240 --> 0:17:07.560 it's actually not even moving at all. It's it's no 0:17:07.600 --> 0:17:11.720 one's tripped that trap yet. You start walking down the tunnel. 0:17:11.720 --> 0:17:13.720 So the fan is behind you and you just have 0:17:13.760 --> 0:17:17.200 a big, expansive tunnel in front of you. Now, as 0:17:17.200 --> 0:17:19.199 you walk down the tunnel, you see that there is 0:17:19.200 --> 0:17:22.440 a split from the tunnel off let's say to your left, 0:17:23.119 --> 0:17:26.160 and it's just a second, smaller tunnel that you seek 0:17:26.400 --> 0:17:28.080 kick down the door. No, no, no, there's no door. 0:17:28.160 --> 0:17:30.680 It's just just an open it's just an opening. But 0:17:30.680 --> 0:17:33.000 but I like your initiative. You didn't even have to 0:17:33.080 --> 0:17:35.800 roll for it, all right. But you continue on down 0:17:35.840 --> 0:17:38.840 and you come to your first actual door in that 0:17:38.920 --> 0:17:42.600 main tunnel. Now you can do your kicking, and it 0:17:42.640 --> 0:17:46.119 works because that door will only open outward into the 0:17:46.160 --> 0:17:48.120 main hall. This is a valve, and it's a one 0:17:48.119 --> 0:17:51.960 way valve, right, so air can go from the fan 0:17:52.560 --> 0:17:55.600 through the main pipe, but it can't be sucked back 0:17:55.680 --> 0:18:00.160 this way, got it. So if airs, if airs being pulled, 0:18:00.240 --> 0:18:03.399 that door slam shut and nothing, not even your mighty 0:18:03.520 --> 0:18:07.240 kick will open it. So since there are no differentials 0:18:07.240 --> 0:18:09.600 in air pressure, your kick opens the door. You continue 0:18:09.640 --> 0:18:13.760 down the hall. I'm gonna skip the cobalt encounter. As 0:18:13.800 --> 0:18:17.040 you continue down the tunnel, you see a door on 0:18:17.119 --> 0:18:21.280 your left. Now, this door is the other valve. This 0:18:21.359 --> 0:18:24.760 is the valve, that is the bypass valve. And in fact, 0:18:24.800 --> 0:18:26.679 if you were to kick down that door, but you 0:18:26.720 --> 0:18:29.520 can do oh ah, yeah, I kicked down the door. Excellent. 0:18:29.760 --> 0:18:34.280 So the door opens inward into that secondary tunnel. There's 0:18:34.320 --> 0:18:37.480 no bugbears there is an al bear, but he's currently 0:18:37.480 --> 0:18:40.480 on break. So you kick down the door. UH. That 0:18:40.600 --> 0:18:44.359 opens the pathway to the bypass UH top tube or 0:18:44.400 --> 0:18:48.440 bypass pipe. So the first tunnel that you passed way 0:18:48.480 --> 0:18:50.960 back when on the left, it's the same it's that 0:18:51.040 --> 0:18:55.640 same pathway. So this door will only open when air 0:18:55.760 --> 0:18:59.920 is being pulled through back towards the fans speak suck 0:19:00.160 --> 0:19:02.600 back toward the fan. So that way you always have 0:19:02.640 --> 0:19:05.359 one valve that's open and one valve that's closed, and 0:19:05.440 --> 0:19:08.040 it all depends upon air flow. So there's no mechanical 0:19:08.160 --> 0:19:11.879 or electrical need to to change these valves. It's just 0:19:11.960 --> 0:19:14.720 the airflow that does it automatically. So if the air 0:19:14.720 --> 0:19:17.359 flow is being pulled back, the bypass valve is open, 0:19:17.800 --> 0:19:20.959 the main valve is shut, and because the bypass pipe 0:19:21.400 --> 0:19:25.120 completely bypasses that main valve, air can still flow through. 0:19:25.920 --> 0:19:29.040 So now we're going to have to use a an 0:19:29.040 --> 0:19:33.160 example to talk about what happens when the canister comes by. 0:19:33.240 --> 0:19:37.360 So the canister starts rocketing down the path toward the 0:19:37.359 --> 0:19:41.280 fan side, so air is being pulled through. It ends 0:19:41.359 --> 0:19:44.040 up passing a switch. That switch tells the fan to 0:19:44.119 --> 0:19:46.280 stop blowing by. Of course, that's going to take a 0:19:46.320 --> 0:19:50.199 little time. So the cancer continues down towards the pathway. 0:19:50.359 --> 0:19:55.040 The canister ends up passing that bypass valve which is open. 0:19:55.640 --> 0:19:59.040 So once the canistor is cleared the bypass valve, because 0:19:59.080 --> 0:20:01.600 you have an air tight seal between the main valve 0:20:01.640 --> 0:20:05.320 and the canister, that air between the two starts to 0:20:05.359 --> 0:20:08.960 get compressed, and that compressed air begins to push back 0:20:09.000 --> 0:20:11.760 against the canister, slowing it down, and thus you have 0:20:11.840 --> 0:20:14.760 air brakes. That was a long way to go for 0:20:14.840 --> 0:20:18.160 that explanation, but honestly, without the use of visual aids, 0:20:18.200 --> 0:20:21.360 I wasn't sure how it is going to explain how 0:20:21.400 --> 0:20:24.000 this actually works in a way that would remotely make sense. 0:20:24.240 --> 0:20:27.680 Uh you now get two d and thirty gold pieces 0:20:27.680 --> 0:20:32.960 a piece and the princesses in another castle. Okay, okay, well, 0:20:32.960 --> 0:20:38.800 good adventure. You're welcome. I'm on a level three gamester um. Yeah. 0:20:38.840 --> 0:20:41.600 So obviously, if the if the fan were switched the 0:20:41.640 --> 0:20:44.840 other way where the canstor is blowing down the the pipe, 0:20:45.080 --> 0:20:47.520 the main valve would be opened, the bypass valve would 0:20:47.520 --> 0:20:49.960 be shut, and that would be it. There would it 0:20:49.960 --> 0:20:53.280 would be no different otherwise? Uh So, yeah, that's that's 0:20:53.320 --> 0:20:55.800 the basic way that this works. And that's you know, 0:20:56.200 --> 0:21:01.320 that's a very very very simple version. And yeah, as 0:21:01.359 --> 0:21:04.919 as complicated as that just sounded out loud, that that 0:21:05.040 --> 0:21:15.520 is as basic as it gets. Really. Yeah, you know, 0:21:15.640 --> 0:21:17.560 I I said a while ago that these things have 0:21:17.600 --> 0:21:20.600 been around since the eighteen fifties at least. So let 0:21:20.680 --> 0:21:24.399 us go to the way back machine and it's been 0:21:24.440 --> 0:21:34.480 out of use for so long. Kind of dusty in 0:21:34.560 --> 0:21:38.000 here this little yeah you know what, as as as 0:21:38.040 --> 0:21:41.200 cramped as this thing is, it's still cooler than Josh 0:21:41.200 --> 0:21:44.679 and Chuck Studio. I mean not not like in a 0:21:44.720 --> 0:21:49.880 style sense, I mean physically the temperature is lower. Physically, yeah, cooler, Yeah, 0:21:49.960 --> 0:21:53.040 yeah that No, they they're they're pretty hot, yeah they are. 0:21:53.160 --> 0:21:55.480 There are a couple of hot guys. All right, Well, anyway, 0:21:55.760 --> 0:21:58.760 let's just where are we setting this to? Uh too? 0:21:59.760 --> 0:22:05.800 To Greece? Sure, well, okay, like ancient Greece, modern Grease. Okay, 0:22:05.800 --> 0:22:07.600 I was really hoping you were going to say Greece too, 0:22:07.680 --> 0:22:12.639 but okay, to Grease it is. Here we go. Well, 0:22:12.800 --> 0:22:15.960 we do have chills and they are multiplying, but that 0:22:16.040 --> 0:22:18.040 was Greece. One. I'm sorry, I don't remember any lyrics 0:22:19.520 --> 0:22:23.080 don't want to. It's it says a lot for you 0:22:23.119 --> 0:22:26.400 and little for me. So there was a mathematician who 0:22:26.720 --> 0:22:29.439 started writing about the concept of using pressurized guess to 0:22:29.440 --> 0:22:33.960 produce mechanical motion. I know this guy, Yeah, Hero of Alexandria, 0:22:34.040 --> 0:22:38.480 also known as Heron. He's a pretty smart dude, was 0:22:38.560 --> 0:22:41.080 he did you? You know, we talked about it. He is. 0:22:41.119 --> 0:22:43.119 Since we are here in the way back missions and 0:22:43.119 --> 0:22:46.080 he's across the street over there, he's kind of working 0:22:46.080 --> 0:22:48.280 on something else right now, Yeah, I think we're weirding 0:22:48.280 --> 0:22:50.080