Welcome to tech Stuff, a production from I Heart Radio. Hey there, and welcome to tech Stuff. I'm your host, Jovian Strickland. I'm an executive producer with I Heart Radio and I love all things tech. It is time for a tech Stuff classic episode. This episode originally published February twenty three, two thousand and fifteen. It is titled The Six Simple Machines Enjoy. Have you all ever done a podcast on the six classical simple Machines? If not, that might make for an interesting topic. Oh I remember these from school? I do too, is except I don't remember them. What were they? There was the toaster, There was the what the electric camera? Yeah? I think I'm pretty sure the A T M was on their nail gun, right, that's way up there? Yeah, and uh I think, uh, I think perpetual motion. That was one was really simple. It just kept going. The machine simple and it also know as the clock. Yes, yeah, yeah, no, of course the six Simple Machines are far simpler than that, but they are really important. They form the basis of a lot of the machines that we use today, and ultimately, most importantly, they make work easier. Work is hard work is hard, work is hard to explain unless you're a physics teacher and you do it all the time. But it has been many, many years since I took a course in physics, and while I still understand and appreciate simple machines and the concepts of work and force and this sort of thing, it behooved me to do a quick refresher course before doing this podcast. We'll share your knowledge with this, Jonathan. All right, So work is force acting on an object in the direction of motion. Uh. And so you could think of it in the equation of force times distance equals work. All right. Uh. So this is why we we express work in units of force and time, such as a Newton meter and a newton. Since this raises the next question, a newton is the amount of force required to accelerate one m of mass at one per second squared. So these are the basic units we're talking about, although we'll also be talking about uh pound foot as a means of a unit of measurement. Because we're in America and we use antiquated systems of units in our measurements. Then we can't understand how to use this funky you know, metric system approach or or the standard unit approach. Okay, but wait a second, how is work different from force? So force is an agent that results in accelerating or deforming an object. So if you want to get an object to start moving, you have to apply force to it. If you want to punch a hole in a wall, you have to apply force to it. But work is the force acting on that object in the direction of motion. So it's it's it's a it's it encompasses more than just the force. Okay. So if I pushed a wheelbarrow twenty feet over a certain period of time, that would be work, right, But your actual pushing against the wheelbarrow itself is force, So you know, it's it's kind of a perspective thing in a way. But it's very important when you start talking about how much how much work and actual task is versus the amount of force that you have to do to accomplish that task. Okay, And so machines in the simplest way, are something that helps us do work easier, right, Yeah, so that we either have to do the work with less force or uh. Really, machines can change the dynamics of force and distance an interesting way, and sometimes it's ways that might seem counterintuitive to you will definitely talk about something that seems counterintuitive, at least the fort when I first thought of it, it was counterintuitive when we get to h levers, which spoiler alert are actually one of the six. But at any rate, yeah, it means that we don't have to exert as much energy when we are trying to accomplish this task, the specific type of work, whatever that might be. And that was really important. I mean, obviously in early the early days of humanity, you know, we spent most of our effort just trying to make sure we weren't dying, and anything that would save us that kind of effort meant that we could we could reserve more energy for very important things like running away. It's a big one, yeah, But at any rate, so there are four main ways that machines make work easier, and the first is that he can increase the magnitude of a force. So they essentially amplify the amount of force being applied to an object or system. So you are are exerting a certain force upon a machine, the machine amplifies that force applied to whatever the load is. That's usually what we call the the thing that you're having the machine act upon and it amplifies that force so that the load is is experiencing more force being exerted upon it than you are putting into the machine. Okay, so in early humanity terms, you might think of this as something like an AX, right, yeah, that would be one, uh you know, any or a ramp, just a simple ramp, because you would you would be exerting less force to move the object as if you wanted. Let's say you wanted to move an object, huh to a allege that's ten ft above ground level, and if you were to actually just lift that object physically, it would require a certain amount of force on your side. But if you used a ramp, it would decrease, especially a very long, gradually sloped ramp, It would decrease the amount of force you needed to get the thing moving. It would just increase the amount of distance you would have to travel to get it to where it needs to go. We'll talk more about that in a bit. Oh yeah, well, I guess an AX would actually involve more than one kind of simple machine because it has an inclined plane or a wedge on it. Yeah, I thought so, maybe what I should have said would be a club, Yeah, a club that would magnify force, right, yeah. Yeah. There's also the the idea of transferring a force from one place to another, which machines that allow us to apply a force in one place the forces transferred to another place. So uh, this can be uh we'll get into some examples a little bit later. There's also changing the direction of the force, where you may have to apply a force in one direction and it's being exerted in Another classic example of this would be a lever or a pulley where you know the classic lever where I might like it. With a classic leaver, I pushed down on one side, the other side goes up, so I'm actually pushing the opposite direction of where the force is being applied. Okay, so like a seesaw. Yeah. Then there's also the increasing the distance or speed of a force, which is a pretty simple concept. Uh. And this is the one that to me was the most counterintuitive when we get to levers, but I want to save that for when we get there. And of course, a combination of machines can create a wide array of effects, and we'll talk about some compound machines which are uh, you know it's obviously two or more simple machines put together to make something more complex. Okay, well one of these simple machines has got to be the wheel, right, well, wheel and axle to be to be specific. But yes, yeah, I guess without an axle, wheel isn't not as useful, no it you know, they're essentially POGs. Yeah, you could push it a little bit and then you'd have to keep putting it back under the thing. Yeah. In fact, that's exactly how early humans were moving large weights. They would have a collection of logs and they would lay those out on the ground, place a heavy weight on top of the logs. They pushed the heavy weight. The heavy weight would roll across the tops of those logs. But that would mean that you get closer to the edge, right, you're the the end of the object. We get closer to the last remaining log in the front. You would have to pick up the logs in the back, run around, put them down in front of everything. Was not the most efficient means of getting a heavy weight from point A to point B. I bet that was a fun job. Yeah, I mean, now, granted, when all you're trying to do is build a megalithic structure to sacrifice humans on. Well, and here's the thing, the people who were building said megalithic structures often time was not something they were really that concerned about. Yeah, but at any rate, Um, if you're looking at the wheel and axel, we believe that was invented sometime around thirty five hundred b c E. Yeah, the earliest evidence actually comes from thirty two hundred from Sumerian artifacts. And also it appears to have been independently invented in China around Okay, so not shared from the Sumerians, but different people came up with the same idea. Yes, that that seems to be the case. There are some people who suggest that no, there was one common ancestor for all wheel and axles, and that that then proliferated across the rest of the world. But the research I read suggested that in fact it did appear independently, which is kind of cool. Yeah, So this allows for obviously much easier travel and transportation. Right, it reduces the friction that you would experience when you're pushing something against the ground. That makes a lot of sense because I can imagine one of the most common work problems in the ancient world was just getting stuff from one place to another, and it probably wasn't always megalithic structure, materials, you know, moving a giant stone, just moving your supplies. You've got foods you've collected or foraged, You've got you know, tools or building materials you want to take with you. How do you get them from one place to another? I mean, if all you've got is you can carry them on your back, right, you might build a sledge or something so that now you have some sort of animal that's pulling it, but that's not very efficient. It's very slow going, and of course if you hit any terrain that's not conducive to such you know, vehicles, then you're really stuck literally in some cases. So yeah, the wheel reduces friction, right, that's the big thing it does in this in this use. There's another use for the wheel and axle that we'll talk about in a second, But when you attach it to something like a cart and you have an axle and wheel set up there, then the wheels turning reduces the friction that you experience when you're pushing this against the ground, and it reduces the amount of force you need to use to get this thing moving. Um. It's you know, pretty simple concept. And there are two different, really you know types of wheel and axles. There's the type of wheel and axle where the wheel can move freely around the axles, the axle remains stationary in act to the wheel. The wheel just rotates around the axle. And then there's the fixed that that one would be fixed to the frame of the cart, so the axle is fixed and the wheel moved right. And then they're also the type where the axle turns along with the wheel. Uh, and it has to be in some sort of bearing that will hold on and allow it this turning motion. I'm trying to think what would be the advantages and disadvantages of each. So if you have free moving wheels, each wheel can move independently. Um. But if you have wheels attached directly to the axles, then the wheels on each end of one axle will have to move together, which you know, you look at cars, Yeah, you know, if if all of our cars had each wheel moving independently, and some actually do have some four wheel independent drive, uh, then that's different than if they're all working together in concert. If you will and so yeah, I mean they're they're different use cases, and there are different advantages and disadvantages. Uh. The important thing to remember is that this simple machine is one of the things that helped revolutionize humanity and keep humanity alive and allowing it to thrive. Um. Obviously, otherwise we just went and get our stuff to where it needs to be. It would be tough. Uh. So another thing you can do with the wheel and axle besides, you know, attach it to a vehicle and have it moved through. Uh. The the wheel and axel has a multiplying force aspect to it, so the force around the axle. Think of the axle. It's kind of like a small cylinder in the center of a larger cylinder, the larger one being the wheel and the small one being the axle. The rotational force around that small cylinder is greater than the rotational force on the outer cylinder, but the distance traveled on the outer cylinder is greater than the distance traveled in the inner cylinder. Yeah. Okay, Now what that means for us is that you can use a wheel as a means of like a crank or uh, you know, a valve, something along those lines, and you can apply a small amount of force to the outside of that wheel, the force being experienced on the axle part is much greater. So if you have something that normally would be fairly tough to turn, if you have a large enough wheel, it starts to become easier and easier to turn it, which is why you start seeing things like those giant wheel like um uh handles for things like the heavy doors and submarines things like that. So, yeah, that it allows you to move much heavier machinery or gears or whatever using a small amount, relatively small amount of rotational force on a larger surface, and the multiplication of that force is what gives you the ability to do a lot of work. Yeah, I can see that. In like, say, the at the helm of an old ship, you would have a very large wheel, and I'm sure it took a lot of force to move the rudder of the ships. Having a larger wheel probably made it easier. I'm glad you brought that up. I'm glad you brought up the wheel because or the helm obviously, because that that will allow us to talk about some interesting different types of machines, not just the wheel, but our next machine, the lever, because before the helm, before the wheel of a ship, which really didn't come about until the really the late eighteenth century. Yeah, yeah, you see those wheels on ships. Those are all modern inventions. In the long run, the classic way of controlling a ship was with a tiller, which was more like a lever. So a tiller is essentially it's a it's a lever that comes out, you hold onto the end. You make small adjustments on one side, but because the way the lever is adjusted, it makes larger changes with the rudder of the ship. The helm of a ship involves a lot of other parts. It's really a compound um machine ultimately, because you've got the wheel, you've got some pulley systems that connect the wheel to the rudder. It's pretty cool. So I'm glad you brought it up. Well, you know, if you look at a wheel like that as uh, something that allows you to apply force over a greater distance to create more force on a shorter distance in the middle, it's kind of like some types of levers, like, for example, a torque wringe. Right, So if you if you have a wrench and you have a bolt that you know it's really it's really or sorry, it would be a nut. I guess a nut. And it is really hard to loosen. It takes a lot of force to do it. You can do it by having a longer handle on your wrench. The longer the handle, the easier it is to get that thing loosened. Right, And you have to travel a greater distance, uh in a circle a circle right for you to get that that nut to go one complete rotation. But it's far easier as far as the amount of force applied. I like that you pronounce it lever and I pronounce it lever. It's gonna get really interesting when we're talking about leverage. So the data data, Yeah, this is the device that gives us a leverage, and which is really how I would say it. I don't know why I say lever but then I say leverage. I just don't. I guess it's you know, it's just because that song you know, fifty ways to love your lever. Okay, never mind, you love them and then you love them. So remember that. Like we were saying, work equals force times distance, and like Joe was just pointing out, if you increase the distance, that means you you can decrease the amount of force to do the same amount of work, right, or you could increase the amount of force and decrease the amount of distance and get the same amount of work. It's those two factors that determine the amount of work that's done. So using a lever, we can change that amount of force applied. Uh. And the law of the lever proposed by Archimedes you may have heard of him, is that quote magnitudes are an equilibrium at distances reciprocally proportional to their weights. End quote. That clears everything up, but it's essentially what we're talking about. So what are the basic parts of a lever. You've got, uh, your the lever itself is the side that you apply the force to. Yeah, yeah, and then you've got something that it typically has to rest against at some point along the beam. You think of the beam as the full length of whatever the liver is. The fulcrum is the pivot point that it rests against that you you use to help uh apply force to whatever the output side is typically speaking. And uh, the way this works is depending on what side is longer, that's going to travel more distance and and apply less force. So if you have a weight, and you put the short side of a beam under that weight, and then you got a fulcrum there, and then the long side of the beam is the one that you pushed down on. You have to push further to make the weight go up the distance you wanted to go, but you're using less force than you would if you were to just lift the weight up bodily, straight up. So we thought this would be easier to understand with an example. So imagine that you've got a fifty pound weight. I'm just gonna do a little bit of metrics here just at the beginning, and then I apologize. You're just gonna have to use conversions to convert everything over because I didn't do it for everything. But if you're talking about fifty pounds, that's about twenty two point seven trams and you want to lift it up two feet, which is about point six meters. To do this, you have to do a hundred pound feet of work or one thirty five point six newt meters of work, because again it's force times distance. So you'd have the uh fifty pounds of weight times the two feet, and that gets the hundred pound foot work. Now, if you used a lever that was twenty ft long on one side and then ten feet on the other side. So so the side that you're going to apply force too, it's twice as long. And you've got a fulcrum that's just uh that's one ft tall. It would be half the amount of force you would need to lift that load than before um, so it you know, it's it's much easier. And of course if you were to extend the lever longer, it would be less and less force, but you have to travel greater distances to get it up the two feet that you want. This is why you have the famous possibly apocryphal quote, uh that our committees said that he said if he had a lever long enough, he could move the world. I guess that's probably true. Yeah, I guess, well, no, I don't probably using it would depend It would depend on what the the lever or lever was made of, wouldn't it. Because at a certain point, when you're trying to move things of great enough mass are taking enough force to move, you'd reach the breaking point of your lever, wouldn't you. Well, yeah, I mean, if you had something that was that long, unless it had incredible strength, it would uh, it would break under its own weight. We'll be back with more of the six simple machines after these brief messages. So leavers change the direction or they can change the direction of an applied force, but depends upon the input and output output forces relative to the fulcrum. And there are three classes of levers. So the one we just talked about that example, the you got the it's it's like the seesaw looking type of lever. That's a the first class style of lever. Okay, So one side of the seesaw is longer than the other side. You can use the longer side to lift heavier loads. And it also changes the direction of the applied force. That's one of the one of the elements of it. The second class is more like a wheelbarrow, which involves too simple machines. You have the wheel and axle, but you also have levers. The handles act as levers. Now in that case, the fulcrumb is on one end of the entire beam. Think of the handles as a beam. So the fulcrumb in this case the wheel is weigh on one end. Then you have the load, which is the actually little load that's inside the wheelbarrow. Then you have the handles the input that you create. So it's different from the seesaw right, where you would have the fulcrum in the center. Now you have the fulcrum on the end, then the load and then you lifting it this one. Instead of reversing the direction of the force, it's the same direction right because you're lifting up on a wheelbarrow, handles and it and it lifts the load up as well. So it's different from uh, the first class of leavers. The third class is the one that seems the most counterintuitive if you first think about it. So would the flat end of a crowbar be a second class lever because they're what you're doing is you don't have the full crumb in the middle. You're you're pressing the end against the inside of the door frame, say, and then a little bit further towards the end you're holding is what's mashing against the door and you're using it to pry like a prying action. Seems like second class levers. It is, And of course, if you were to turn the crowbar around to use the curved end be a first class just like a Claude hammer would be as well. Here's a Claude hammer to remove nails. Uh, so that's a great example. Third class levers are the ones to me that are the most counterintuitive. Um they have the fulcrum at one end, then you have the input force, then you have the output force. So you know when the wheelbarrow example, we've got input force on one end, then output in the middle, then the fulcrum in this case fulcrum input output. And you might think, wait a minute, what the how does that even work? It doesn't sound like and why would you want to use that? Because if you use if you use the sort of lever, it has what we call an ideal mechanical advantage of less than one ideal mechanical advantage. This is what's telling you how how how much it's helping you in the sense of how much force you have to apply versus the force that you're getting out of this too for the issue of making work right, So here you're you're actually at a loss. Yeah, and you might wonder, well, why would you want to do that? And the reason is that you are that output force has actually applied over a greater distance. So it's kind of the reverse of what we were talking about. Earlier about how with the wheel, when you have the greater distance, you have to apply less force, but you get more distance. In this case, you have to apply more forced down at the input, but you're getting greater distance at the output, which is really useful if you're up to bat. A baseball bat is a third class leaver. So this would be like my club example earlier exactly, that's essentially a third class lever or a first class bunk in the head. Uh So anyway, yeah, very interesting. Some of the some of this to me is counterintuitive. I'm sure to some people that are like, this all makes perfect sense. I don't know what you're talking about with counterintuitive, but I remember the first time I read about they were using a hockey stick as a an example of a third class lever from one of the sources. I was looking over and I thought, I'm from Georgia. That example means nothing to me. And then they said baseball band, Like, Okay, now I understand what you're saying. We're gonna wrap up the six simple machines in just a moment, but before we do that, let's take another quick break. Next, we have another simple machine, the inclined plane, and it is so inclined. It's the simplest of all simple machines. Perhaps it's it's definitely, I mean it's it's essentially a ramp, you know, that's really what is So when you want to move, when you want to move a load from one elevation to a different elevation and it's too heavy to just lift, a ramp can often help out. It decreases the amount of force you need to get the load to that height, but it increases the distance you must travel in order to do so. So when we were talking earlier about the wheels and the logs and you know, this this concept of how much time is it going to take to do this? Uh, the pyramids were built by moving these enormous blocks of stone up very long ramps to get to their their various elevations because the blocks of stone are far too heavy to just lift and put them in place. Wow. I think for a long time we didn't know how they were built, right, Yeah, No, there was a lot of speculation about how it actually happened. But as it turns out, the ramp method is the one that was used to You know, if you build the ramp out long enough, then you decrease that force to make it more manageable, but you do have to make the ramp longer and longer to increase that mechanical advantage. Right, That does mean you have to travel further and further, and makes sense because you know, you just intuitively understand that a short ramp is going to be much more steep, and that steepness is going to make make it so that you have to apply more force to get whatever the load is up that ramp. That you're familiar with. This in simple walking terms, I mean you take fewer steps going up a short steep incline to the same altitude versus a very long, slow, gradual slope to an equal altitude, but you but it's still you know, easier taking the long, slow way. You're still doing the same amount of work overall, because again it's four times distance, but you're doing less force per unit of walking, so it doesn't feel like it's as exhausting unless the ramp is so long as to make the journey intolerably long, which could be a possibility if you have enough space. But infinite ramp that's a good band name. Yeah, Yeah, I have a feeling that just just be a jam band, play those like incredibly long jam sessions that don't ever go anywhere. But yeah, if you were to take that same weight we were talking about that fifty pound weight we were mentioning earlier, we have a ramp that's two ft tall and four ft long. It'll take half the amount of force needed to get it moving over twice the distance of just lifting it up those two feet, So again saves you the force needed to move this thing. Uh. Then making that ramp longer would decrease the steepness and the force needed to move the weight even further, but it would increase the distance at the same time. And now we start getting into some of the the advanced simple machines. The ones we've named so far are really you know, most people argue this is the the furthest can break down a simple machine. The other ones have some elements to them that are similar to the previous ones, like the pulley, which is kind of similar to levers and also to wheel and axle. I feel like, maybe, of all the simple machines, I encounter a pulley the least often in my life, at least at least visibly, right, So pully maybe if I were a sailor. Yeah, we we You probably know what a pulley looks like. Um, generally speaking, you've got like a grooved wheel that's suspended within a frame, can spin freely within that frame. You feed a rope through it, or line through it if you're a sailor. Uh. And this allows you to change the direction of force, but it doesn't change the amount of force you need to move a weight all by itself. So so, changing the direction of force, even if you're not adding force, can be very useful because, as everyone knows, it's much easier to pull down on something using your body weight and gravity tare advantage than it is to push up with the same force. Right. So, and I should clarify when I say this, I'm really talking about a suspended pulley from like a beam or some other stationary object. And the weight you want doesn't have a pulley attached to it, because you could attach a pully to the weight and then tie one end off to something like a beam and you could hold the other end, in which case it doesn't reverse the direction of the force. Right you are pulling up, but it reduces the amount of force you need to lift the weight. So if you if you do it that way, where the beam is holding one end of the rope and you're holding the other end of the rope, you're reducing the amount of force, but you're not changing the direction. If, on the other hand, the beam is holding the pulley and the rope is just attached to a weight, you're reversing the direction, but you're not reducing the amount of force. Um, but I bet there is a way to reduce the amount of force. Yeah, you just gotta add more police. So let's say we put how many how many you got? Have you heard of block and tackle? All right? First, let's let's go with the simplest approach, where we have two pulleys. Let's say you have one pulley attached to a stationary thing like a beam hanging from the roof, right, and then you have a second pulley that's attached to the weight that you plan on moving. You tie one end of your line off onto the beam or even onto that that first pulley that we're talking about. Feed the line down through the pulley that's attached to the weight. Feed that line up through the pulley that's attached to the beam, and then you finally hold the other end. You pull down, and now the weight has been reduced the amount of force you need, or at least the perceivable weight you feel. The amount of force you need to move that weight has been reduced a half. But you have to move twice as you have to pull twice as far, twice as much rope to move it the distance that you wanted to go. So, in other words, if you want the symmetry of physics is beautiful. Yeah, so if you want to have lifted that two feet, you have to pull four feet of rope, all right, But you could add more pulleys and this would decrease the amount of force further while increasing the amount of distance more. You would actually have to have longer rope obviously, if you started to add lots and lots of of pulleys and you had a full block and tackle system. But this would allow you to move incredible weights using a relatively small amount of force. You would just have to be willing to pull lots of rope in order to do it. Or line all, all of the sailors who listen are just singing, there's such a Rube saying rope. I guess maybe they don't like the word rope. It's it's line. It's not rope, it's line on a ship. Yeah, I spent a little, tiny, tiny amount of time on a ship and I got I got corrected so many times. Well, we should have a face off between geometris and geometrs, geometricians and geometris, geomet geometrists or I think, Yeah, I think of geometry as trickery, so I I my vote goes to the geometric stars, geometry teachers, and sailors, and they can argue about lines. I knew some geometry teachers who could definitely take on some sailors in their time. Okay, let's let's do another one. All right, sure, what what do you want to do? The screw? The simple machine? Right, Yes, I am so, if I'm not mistaken. The screw is basically just an inclined plane in a particular configuration. Yeah, it's an inclined plane that is wrapped around the core of something like a like a shaft. So you take a shaft, you put an inclined plane, and you spiral it around the shaft and you get a screw and uh, screws. Can it's a tiny circular ramp. Yeah, And that circular part is what's really important, because it means that if you apply a rotational force to the screw, it provides a linear force along the length of the shaft that is greater than the force you used to turn the screw in the first place. Uh. This, of course is dependent upon the pitch. The pitch. The pitch the pitch and screws is The description is that it's the distance between the treads. So the the sections of the ramp, the closer together they are, the greater the ideal mechanical advantage. And the reason is the mechanical advantages dependent upon the length of the inclined plane the ramp to the length of the shaft. So if the treads are closer together, that means if you were to untwirl this, the ramp would be much much, much longer because the cram more of it along the length of the screw. Yeah, that makes sense. So yeah, that's like having that longer, slower gradient of ramp up to the summit, right exactly. Yeah, So it's interesting to think of it that way. But yeah, the treads are closer together, it's going to exert a greater force when you turn this this. These of course, have been really useful in lots of different uh applications, every thing from you know, just securing something to the wall, for example, because it has a great holding force that way to lifting things. Our comedies, screw was a way of drawing water out, which was kind of cool. Um. You know, it's it's an interesting simple machine, and it's something that if you were to look at, like you go to a hardware store and you look at a bunch of screws, you wouldn't necessarily think this is a machine, right. You think of it as a tool or or you know, just something that you need. But it actually is one of the simple machines. And only is it one of the simple machines, but like we're pointing out, it's a simple machine that's made up of an even simpler machine, which is kind of cool. Um. Yeah, it's an interesting, uh piece of machinery, if you if you will. And the earliest evidence of screws come from Greece, uh so they were actually one of the later simple machines to arrive on the scene. And the grand scheme of things had had a screwed. Yeah. Yeah, that was the one that drew water up. Yeah, the water the water screwe. Yep, it's really cool. If you've never seen any illustrations of that, you should look it up. Our commedie screw is pretty cool. I think we talked about it, and we did a tech Stuff podcast ages ago about our comedes, and I'm pretty sure we talked about our commedity screw. We we spent a lot of that time. That was a Cris Pallette episode, and we've been a lot of that time talking about some of the crazy inventions attributed to our commedes, perhaps apocryphal e Like the claw that reaches out of the city walls and grab ships. That was one of them. Yeah. Alright, so let's talk about the last of the simple machines. Yet another application of the ramp, right, Yeah, this is the wedge. So a wedge is essentially two inclined ramps that are against each other to create this wedge shape. And uh, they can be used to do a couple of different things. They can be driven beneath a weight to lift it up. So this would be you know a wedge that you would you would put the end of it under the weight, and you would apply force to the the flat end of the wedge, the back end, the butt end of it, and that would end up pushing the weight upward because of the the design of the wedge, or you could use it to be destructive. So Jonathan, I have a question for you. Ask away, Joe, have you ever split wood with a mall? I want split wood with Darth mall? No, I'm serious now, no lightsaber jokes. Have you ever split wood with a mall? I have not. I've only split wood with axes, which are not necessarily easy tools to use for that purpose. Well, a splitting mall is. It's hard work, but man, it is a really satisfying feeling. So imagine it's sort of like an ax. Uh. It is a sort of a combination of an ax and a sledge hammer. If you can imagine that it's a long handle and then at the end of the handle you have this bulky heavy head that is basically a wedge on one end and then a sledge hammer on the other. Just I think to increase the weight basically, and the wedge doesn't even necessarily have to be that sharp. I think it usually isn't the one I used wasn't very sharp, but because of the weight, it was a one hit splitter. So you'd put a log segment out and you'd hit it once and it would just cleave apart, which is pretty impressive. Yeah. Oh man, it it felt good to do, but it got tiring after a while. Yeah. And see you can see that there's some like within the mall. There are two machines here at work. Right, You've got the lever as far as the handle, that's what's allowing you to apply leverage when you're doing your swing, and then you have the wedge, which is doing the actual splitting. So the wedge, what it's doing is it's applying that downward force and changing the direction of that forced to outward. Yeah, so that's why you when you hit the log, that outward force splits the log apart. And it's really cool. I tried doing the same thing with access, which you can do, but it takes more effort, yeah, because the axe head probably just doesn't heavy enough that. Yeah, it's you know, you're using, so you have to take up some of the force that normally would have been taken care of by the the tool itself. It's pretty cool. I've never done that now. Uh, it's yeah, give it a shot sometimes. All right, next time I'm out in the woods and I'm just thinking, you know what I need to do, It's just split get your hands on the mall. You know, my family actually called it a maddic. I had to look it up and figure out that I was wrong about what a mattock was. A matic is a thing with a differently oriented head. It's kind of like a pick axe got you. But that was just how your family referred to it. It was a mall. I have determined now. So yeah, these are um, that's the that's the last of the six simple ones. But then there are also other machines that we can talk about, compound machines. I mentioned those earlier. These are the machines that combined two or more simple ones. Ship's Home is one of the examples we already talked about. Wheelbarrow was another one we talked about. Scissors would be a great example because with scissors, you've got a pair of wedges. Uh, those would be the blades of the scissors, and you have a lever. The handle that you hold would be a lever. The fulcrum would be the center that that binds them together. Uh, and so that's what allows you to use scissors. Compound machines have more moving parts than simple machines, but that's not necessarily a good thing overall, because the more parts you have, the more you have to overcome friction. If you add lots and lots of different parts, that friction could be very difficult to overcome and it could end up generating a lot of heat, which is why very complex machines like a car engine require coolens and lubricants in order for them to continue to work properly. Um. That means there's also a loss and efficiency. However, the compound machines have greater mechanical advantage. You actually multiply the problem. You multiply the mechanical advantage of each of the individ dual um simple machines within the compound machine to determine what its mechanical advantages. So as long as every single simple machine in your compound machine has that ideal mechanical advantage of greater than one, the more you add, the greater mechanical advantage the compound machine has. And thus we get to the room Goldberg device. Yeah, what what's it? Has like a goldfish that operates a magnifying glass that burns a rope and yeah, exactly, and then you get an okay go video out of it. Not all those would be simple machines, I don't think the magnifying glass, but even some of those would be compound machines. That would be a collection of simple machines. But there you go. That's the collection of simple machines and what they do and why they're important. Um, it's it was fun to look back at this, even though, like again, this is something that any of our listeners who are still in school, they may be rolling their eyes for the whole thing because they're thinking they've already learned all this stuff and that is repetitive. But for those of us who graduated a long time ago, and perhaps I have not kept up with physics the way we might have, you know, wanted to. I loved physics when I was a kid. It was one of my favorite favorite subjects in school. I wish I had appreciated science more when I was in school. I didn't. I didn't really come to love science until after I was out of school, and then I wished I could go back and and treat it with the respect it deserves. Out of all the sciences, uh, classical physics was the one that appealed to me most because it was the one that made sense to me, because it was it was the physics of the world that I could observe around me, and I loved it. I just I understood it and I took to it. Not so much with the biology and chemistry as it turns out. I mean, I did well, but they were harder. They were harder to learn for me. That wraps up the classic episode on the six Simple machines. I've seen so many cartoons that explained those and I love them so much. Uh, really fascinating stuff to me, like to think back on how these underlies so many machines today. I mean, at least the mechanical ones. Once you start getting into digital, it's a whole different ball game. But I hope you found that interesting. If you have suggestions for topics I should cover for future episodes of tech Stuff, please reach out to me. The best way to do that is on Twitter. To handle for the show is text stuff H s W and I'll talk to you again really soon. Text Stuff is an I heart radio production. For more podcasts from my heart Radio, visit the i heart Radio app, Apple podcasts, or wherever you listen to your favorite shows.

Welcome to tech Stuff, a production from I Heart Radio. Hey there, and welcome to tech Stuff. I'm your host, Jovian Strickland. I'm an executive producer with I Heart Radio and I love all things tech. It is time for a tech Stuff classic episode. This episode originally published February twenty three, two thousand and fifteen. It is titled The Six Simple Machines Enjoy. Have you all ever done a podcast on the six classical simple Machines? If not, that might make for an interesting topic. Oh I remember these from school? I do too, is except I don't remember them. What were they? There was the toaster, There was the what the electric camera? Yeah? I think I'm pretty sure the A T M was on their nail gun, right, that's way up there? Yeah, and uh I think, uh, I think perpetual motion. That was one was really simple. It just kept going. The machine simple and it also know as the clock. Yes, yeah, yeah, no, of course the six Simple Machines are far simpler than that, but they are really important. They form the basis of a lot of the machines that we use today, and ultimately, most importantly, they make work easier. Work is hard work is hard, work is hard to explain unless you're a physics teacher and you do it all the time. But it has been many, many years since I took a course in physics, and while I still understand and appreciate simple machines and the concepts of work and force and this sort of thing, it behooved me to do a quick refresher course before doing this podcast. We'll share your knowledge with this, Jonathan. All right, So work is force acting on an object in the direction of motion. Uh. And so you could think of it in the equation of force times distance equals work. All right. Uh. So this is why we we express work in units of force and time, such as a Newton meter and a newton. Since this raises the next question, a newton is the amount of force required to accelerate one m of mass at one per second squared. So these are the basic units we're talking about, although we'll also be talking about uh pound foot as a means of a unit of measurement. Because we're in America and we use antiquated systems of units in our measurements. Then we can't understand how to use this funky you know, metric system approach or or the standard unit approach. Okay, but wait a second, how is work different from force? So force is an agent that results in accelerating or deforming an object. So if you want to get an object to start moving, you have to apply force to it. If you want to punch a hole in a wall, you have to apply force to it. But work is the force acting on that object in the direction of motion. So it's it's it's a it's it encompasses more than just the force. Okay. So if I pushed a wheelbarrow twenty feet over a certain period of time, that would be work, right, But your actual pushing against the wheelbarrow itself is force, So you know, it's it's kind of a perspective thing in a way. But it's very important when you start talking about how much how much work and actual task is versus the amount of force that you have to do to accomplish that task. Okay, And so machines in the simplest way, are something that helps us do work easier, right, Yeah, so that we either have to do the work with less force or uh. Really, machines can change the dynamics of force and distance an interesting way, and sometimes it's ways that might seem counterintuitive to you will definitely talk about something that seems counterintuitive, at least the fort when I first thought of it, it was counterintuitive when we get to h levers, which spoiler alert are actually one of the six. But at any rate, yeah, it means that we don't have to exert as much energy when we are trying to accomplish this task, the specific type of work, whatever that might be. And that was really important. I mean, obviously in early the early days of humanity, you know, we spent most of our effort just trying to make sure we weren't dying, and anything that would save us that kind of effort meant that we could we could reserve more energy for very important things like running away. It's a big one, yeah, But at any rate, so there are four main ways that machines make work easier, and the first is that he can increase the magnitude of a force. So they essentially amplify the amount of force being applied to an object or system. So you are are exerting a certain force upon a machine, the machine amplifies that force applied to whatever the load is. That's usually what we call the the thing that you're having the machine act upon and it amplifies that force so that the load is is experiencing more force being exerted upon it than you are putting into the machine. Okay, so in early humanity terms, you might think of this as something like an AX, right, yeah, that would be one, uh you know, any or a ramp, just a simple ramp, because you would you would be exerting less force to move the object as if you wanted. Let's say you wanted to move an object, huh to a allege that's ten ft above ground level, and if you were to actually just lift that object physically, it would require a certain amount of force on your side. But if you used a ramp, it would decrease, especially a very long, gradually sloped ramp, It would decrease the amount of force you needed to get the thing moving. It would just increase the amount of distance you would have to travel to get it to where it needs to go. We'll talk more about that in a bit. Oh yeah, well, I guess an AX would actually involve more than one kind of simple machine because it has an inclined plane or a wedge on it. Yeah, I thought so, maybe what I should have said would be a club, Yeah, a club that would magnify force, right, yeah. Yeah. There's also the the idea of transferring a force from one place to another, which machines that allow us to apply a force in one place the forces transferred to another place. So uh, this can be uh we'll get into some examples a little bit later. There's also changing the direction of the force, where you may have to apply a force in one direction and it's being exerted in Another classic example of this would be a lever or a pulley where you know the classic lever where I might like it. With a classic leaver, I pushed down on one side, the other side goes up, so I'm actually pushing the opposite direction of where the force is being applied. Okay, so like a seesaw. Yeah. Then there's also the increasing the distance or speed of a force, which is a pretty simple concept. Uh. And this is the one that to me was the most counterintuitive when we get to levers, but I want to save that for when we get there. And of course, a combination of machines can create a wide array of effects, and we'll talk about some compound machines which are uh, you know it's obviously two or more simple machines put together to make something more complex. Okay, well one of these simple machines has got to be the wheel, right, well, wheel and axle to be to be specific. But yes, yeah, I guess without an axle, wheel isn't not as useful, no it you know, they're essentially POGs. Yeah, you could push it a little bit and then you'd have to keep putting it back under the thing. Yeah. In fact, that's exactly how early humans were moving large weights. They would have a collection of logs and they would lay those out on the ground, place a heavy weight on top of the logs. They pushed the heavy weight. The heavy weight would roll across the tops of those logs. But that would mean that you get closer to the edge, right, you're the the end of the object. We get closer to the last remaining log in the front. You would have to pick up the logs in the back, run around, put them down in front of everything. Was not the most efficient means of getting a heavy weight from point A to point B. I bet that was a fun job. Yeah, I mean, now, granted, when all you're trying to do is build a megalithic structure to sacrifice humans on. Well, and here's the thing, the people who were building said megalithic structures often time was not something they were really that concerned about. Yeah, but at any rate, Um, if you're looking at the wheel and axel, we believe that was invented sometime around thirty five hundred b c E. Yeah, the earliest evidence actually comes from thirty two hundred from Sumerian artifacts. And also it appears to have been independently invented in China around Okay, so not shared from the Sumerians, but different people came up with the same idea. Yes, that that seems to be the case. There are some people who suggest that no, there was one common ancestor for all wheel and axles, and that that then proliferated across the rest of the world. But the research I read suggested that in fact it did appear independently, which is kind of cool. Yeah, So this allows for obviously much easier travel and transportation. Right, it reduces the friction that you would experience when you're pushing something against the ground. That makes a lot of sense because I can imagine one of the most common work problems in the ancient world was just getting stuff from one place to another, and it probably wasn't always megalithic structure, materials, you know, moving a giant stone, just moving your supplies. You've got foods you've collected or foraged, You've got you know, tools or building materials you want to take with you. How do you get them from one place to another? I mean, if all you've got is you can carry them on your back, right, you might build a sledge or something so that now you have some sort of animal that's pulling it, but that's not very efficient. It's very slow going, and of course if you hit any terrain that's not conducive to such you know, vehicles, then you're really stuck literally in some cases. So yeah, the wheel reduces friction, right, that's the big thing it does in this in this use. There's another use for the wheel and axle that we'll talk about in a second, But when you attach it to something like a cart and you have an axle and wheel set up there, then the wheels turning reduces the friction that you experience when you're pushing this against the ground, and it reduces the amount of force you need to use to get this thing moving. Um. It's you know, pretty simple concept. And there are two different, really you know types of wheel and axles. There's the type of wheel and axle where the wheel can move freely around the axles, the axle remains stationary in act to the wheel. The wheel just rotates around the axle. And then there's the fixed that that one would be fixed to the frame of the cart, so the axle is fixed and the wheel moved right. And then they're also the type where the axle turns along with the wheel. Uh, and it has to be in some sort of bearing that will hold on and allow it this turning motion. I'm trying to think what would be the advantages and disadvantages of each. So if you have free moving wheels, each wheel can move independently. Um. But if you have wheels attached directly to the axles, then the wheels on each end of one axle will have to move together, which you know, you look at cars, Yeah, you know, if if all of our cars had each wheel moving independently, and some actually do have some four wheel independent drive, uh, then that's different than if they're all working together in concert. If you will and so yeah, I mean they're they're different use cases, and there are different advantages and disadvantages. Uh. The important thing to remember is that this simple machine is one of the things that helped revolutionize humanity and keep humanity alive and allowing it to thrive. Um. Obviously, otherwise we just went and get our stuff to where it needs to be. It would be tough. Uh. So another thing you can do with the wheel and axle besides, you know, attach it to a vehicle and have it moved through. Uh. The the wheel and axel has a multiplying force aspect to it, so the force around the axle. Think of the axle. It's kind of like a small cylinder in the center of a larger cylinder, the larger one being the wheel and the small one being the axle. The rotational force around that small cylinder is greater than the rotational force on the outer cylinder, but the distance traveled on the outer cylinder is greater than the distance traveled in the inner cylinder. Yeah. Okay, Now what that means for us is that you can use a wheel as a means of like a crank or uh, you know, a valve, something along those lines, and you can apply a small amount of force to the outside of that wheel, the force being experienced on the axle part is much greater. So if you have something that normally would be fairly tough to turn, if you have a large enough wheel, it starts to become easier and easier to turn it, which is why you start seeing things like those giant wheel like um uh handles for things like the heavy doors and submarines things like that. So, yeah, that it allows you to move much heavier machinery or gears or whatever using a small amount, relatively small amount of rotational force on a larger surface, and the multiplication of that force is what gives you the ability to do a lot of work. Yeah, I can see that. In like, say, the at the helm of an old ship, you would have a very large wheel, and I'm sure it took a lot of force to move the rudder of the ships. Having a larger wheel probably made it easier. I'm glad you brought that up. I'm glad you brought up the wheel because or the helm obviously, because that that will allow us to talk about some interesting different types of machines, not just the wheel, but our next machine, the lever, because before the helm, before the wheel of a ship, which really didn't come about until the really the late eighteenth century. Yeah, yeah, you see those wheels on ships. Those are all modern inventions. In the long run, the classic way of controlling a ship was with a tiller, which was more like a lever. So a tiller is essentially it's a it's a lever that comes out, you hold onto the end. You make small adjustments on one side, but because the way the lever is adjusted, it makes larger changes with the rudder of the ship. The helm of a ship involves a lot of other parts. It's really a compound um machine ultimately, because you've got the wheel, you've got some pulley systems that connect the wheel to the rudder. It's pretty cool. So I'm glad you brought it up. Well, you know, if you look at a wheel like that as uh, something that allows you to apply force over a greater distance to create more force on a shorter distance in the middle, it's kind of like some types of levers, like, for example, a torque wringe. Right, So if you if you have a wrench and you have a bolt that you know it's really it's really or sorry, it would be a nut. I guess a nut. And it is really hard to loosen. It takes a lot of force to do it. You can do it by having a longer handle on your wrench. The longer the handle, the easier it is to get that thing loosened. Right, And you have to travel a greater distance, uh in a circle a circle right for you to get that that nut to go one complete rotation. But it's far easier as far as the amount of force applied. I like that you pronounce it lever and I pronounce it lever. It's gonna get really interesting when we're talking about leverage. So the data data, Yeah, this is the device that gives us a leverage, and which is really how I would say it. I don't know why I say lever but then I say leverage. I just don't. I guess it's you know, it's just because that song you know, fifty ways to love your lever. Okay, never mind, you love them and then you love them. So remember that. Like we were saying, work equals force times distance, and like Joe was just pointing out, if you increase the distance, that means you you can decrease the amount of force to do the same amount of work, right, or you could increase the amount of force and decrease the amount of distance and get the same amount of work. It's those two factors that determine the amount of work that's done. So using a lever, we can change that amount of force applied. Uh. And the law of the lever proposed by Archimedes you may have heard of him, is that quote magnitudes are an equilibrium at distances reciprocally proportional to their weights. End quote. That clears everything up, but it's essentially what we're talking about. So what are the basic parts of a lever. You've got, uh, your the lever itself is the side that you apply the force to. Yeah, yeah, and then you've got something that it typically has to rest against at some point along the beam. You think of the beam as the full length of whatever the liver is. The fulcrum is the pivot point that it rests against that you you use to help uh apply force to whatever the output side is typically speaking. And uh, the way this works is depending on what side is longer, that's going to travel more distance and and apply less force. So if you have a weight, and you put the short side of a beam under that weight, and then you got a fulcrum there, and then the long side of the beam is the one that you pushed down on. You have to push further to make the weight go up the distance you wanted to go, but you're using less force than you would if you were to just lift the weight up bodily, straight up. So we thought this would be easier to understand with an example. So imagine that you've got a fifty pound weight. I'm just gonna do a little bit of metrics here just at the beginning, and then I apologize. You're just gonna have to use conversions to convert everything over because I didn't do it for everything. But if you're talking about fifty pounds, that's about twenty two point seven trams and you want to lift it up two feet, which is about point six meters. To do this, you have to do a hundred pound feet of work or one thirty five point six newt meters of work, because again it's force times distance. So you'd have the uh fifty pounds of weight times the two feet, and that gets the hundred pound foot work. Now, if you used a lever that was twenty ft long on one side and then ten feet on the other side. So so the side that you're going to apply force too, it's twice as long. And you've got a fulcrum that's just uh that's one ft tall. It would be half the amount of force you would need to lift that load than before um, so it you know, it's it's much easier. And of course if you were to extend the lever longer, it would be less and less force, but you have to travel greater distances to get it up the two feet that you want. This is why you have the famous possibly apocryphal quote, uh that our committees said that he said if he had a lever long enough, he could move the world. I guess that's probably true. Yeah, I guess, well, no, I don't probably using it would depend It would depend on what the the lever or lever was made of, wouldn't it. Because at a certain point, when you're trying to move things of great enough mass are taking enough force to move, you'd reach the breaking point of your lever, wouldn't you. Well, yeah, I mean, if you had something that was that long, unless it had incredible strength, it would uh, it would break under its own weight. We'll be back with more of the six simple machines after these brief messages. So leavers change the direction or they can change the direction of an applied force, but depends upon the input and output output forces relative to the fulcrum. And there are three classes of levers. So the one we just talked about that example, the you got the it's it's like the seesaw looking type of lever. That's a the first class style of lever. Okay, So one side of the seesaw is longer than the other side. You can use the longer side to lift heavier loads. And it also changes the direction of the applied force. That's one of the one of the elements of it. The second class is more like a wheelbarrow, which involves too simple machines. You have the wheel and axle, but you also have levers. The handles act as levers. Now in that case, the fulcrumb is on one end of the entire beam. Think of the handles as a beam. So the fulcrumb in this case the wheel is weigh on one end. Then you have the load, which is the actually little load that's inside the wheelbarrow. Then you have the handles the input that you create. So it's different from the seesaw right, where you would have the fulcrum in the center. Now you have the fulcrum on the end, then the load and then you lifting it this one. Instead of reversing the direction of the force, it's the same direction right because you're lifting up on a wheelbarrow, handles and it and it lifts the load up as well. So it's different from uh, the first class of leavers. The third class is the one that seems the most counterintuitive if you first think about it. So would the flat end of a crowbar be a second class lever because they're what you're doing is you don't have the full crumb in the middle. You're you're pressing the end against the inside of the door frame, say, and then a little bit further towards the end you're holding is what's mashing against the door and you're using it to pry like a prying action. Seems like second class levers. It is, And of course, if you were to turn the crowbar around to use the curved end be a first class just like a Claude hammer would be as well. Here's a Claude hammer to remove nails. Uh, so that's a great example. Third class levers are the ones to me that are the most counterintuitive. Um they have the fulcrum at one end, then you have the input force, then you have the output force. So you know when the wheelbarrow example, we've got input force on one end, then output in the middle, then the fulcrum in this case fulcrum input output. And you might think, wait a minute, what the how does that even work? It doesn't sound like and why would you want to use that? Because if you use if you use the sort of lever, it has what we call an ideal mechanical advantage of less than one ideal mechanical advantage. This is what's telling you how how how much it's helping you in the sense of how much force you have to apply versus the force that you're getting out of this too for the issue of making work right, So here you're you're actually at a loss. Yeah, and you might wonder, well, why would you want to do that? And the reason is that you are that output force has actually applied over a greater distance. So it's kind of the reverse of what we were talking about. Earlier about how with the wheel, when you have the greater distance, you have to apply less force, but you get more distance. In this case, you have to apply more forced down at the input, but you're getting greater distance at the output, which is really useful if you're up to bat. A baseball bat is a third class leaver. So this would be like my club example earlier exactly, that's essentially a third class lever or a first class bunk in the head. Uh So anyway, yeah, very interesting. Some of the some of this to me is counterintuitive. I'm sure to some people that are like, this all makes perfect sense. I don't know what you're talking about with counterintuitive, but I remember the first time I read about they were using a hockey stick as a an example of a third class lever from one of the sources. I was looking over and I thought, I'm from Georgia. That example means nothing to me. And then they said baseball band, Like, Okay, now I understand what you're saying. We're gonna wrap up the six simple machines in just a moment, but before we do that, let's take another quick break. Next, we have another simple machine, the inclined plane, and it is so inclined. It's the simplest of all simple machines. Perhaps it's it's definitely, I mean it's it's essentially a ramp, you know, that's really what is So when you want to move, when you want to move a load from one elevation to a different elevation and it's too heavy to just lift, a ramp can often help out. It decreases the amount of force you need to get the load to that height, but it increases the distance you must travel in order to do so. So when we were talking earlier about the wheels and the logs and you know, this this concept of how much time is it going to take to do this? Uh, the pyramids were built by moving these enormous blocks of stone up very long ramps to get to their their various elevations because the blocks of stone are far too heavy to just lift and put them in place. Wow. I think for a long time we didn't know how they were built, right, Yeah, No, there was a lot of speculation about how it actually happened. But as it turns out, the ramp method is the one that was used to You know, if you build the ramp out long enough, then you decrease that force to make it more manageable, but you do have to make the ramp longer and longer to increase that mechanical advantage. Right, That does mean you have to travel further and further, and makes sense because you know, you just intuitively understand that a short ramp is going to be much more steep, and that steepness is going to make make it so that you have to apply more force to get whatever the load is up that ramp. That you're familiar with. This in simple walking terms, I mean you take fewer steps going up a short steep incline to the same altitude versus a very long, slow, gradual slope to an equal altitude, but you but it's still you know, easier taking the long, slow way. You're still doing the same amount of work overall, because again it's four times distance, but you're doing less force per unit of walking, so it doesn't feel like it's as exhausting unless the ramp is so long as to make the journey intolerably long, which could be a possibility if you have enough space. But infinite ramp that's a good band name. Yeah, Yeah, I have a feeling that just just be a jam band, play those like incredibly long jam sessions that don't ever go anywhere. But yeah, if you were to take that same weight we were talking about that fifty pound weight we were mentioning earlier, we have a ramp that's two ft tall and four ft long. It'll take half the amount of force needed to get it moving over twice the distance of just lifting it up those two feet, So again saves you the force needed to move this thing. Uh. Then making that ramp longer would decrease the steepness and the force needed to move the weight even further, but it would increase the distance at the same time. And now we start getting into some of the the advanced simple machines. The ones we've named so far are really you know, most people argue this is the the furthest can break down a simple machine. The other ones have some elements to them that are similar to the previous ones, like the pulley, which is kind of similar to levers and also to wheel and axle. I feel like, maybe, of all the simple machines, I encounter a pulley the least often in my life, at least at least visibly, right, So pully maybe if I were a sailor. Yeah, we we You probably know what a pulley looks like. Um, generally speaking, you've got like a grooved wheel that's suspended within a frame, can spin freely within that frame. You feed a rope through it, or line through it if you're a sailor. Uh. And this allows you to change the direction of force, but it doesn't change the amount of force you need to move a weight all by itself. So so, changing the direction of force, even if you're not adding force, can be very useful because, as everyone knows, it's much easier to pull down on something using your body weight and gravity tare advantage than it is to push up with the same force. Right. So, and I should clarify when I say this, I'm really talking about a suspended pulley from like a beam or some other stationary object. And the weight you want doesn't have a pulley attached to it, because you could attach a pully to the weight and then tie one end off to something like a beam and you could hold the other end, in which case it doesn't reverse the direction of the force. Right you are pulling up, but it reduces the amount of force you need to lift the weight. So if you if you do it that way, where the beam is holding one end of the rope and you're holding the other end of the rope, you're reducing the amount of force, but you're not changing the direction. If, on the other hand, the beam is holding the pulley and the rope is just attached to a weight, you're reversing the direction, but you're not reducing the amount of force. Um, but I bet there is a way to reduce the amount of force. Yeah, you just gotta add more police. So let's say we put how many how many you got? Have you heard of block and tackle? All right? First, let's let's go with the simplest approach, where we have two pulleys. Let's say you have one pulley attached to a stationary thing like a beam hanging from the roof, right, and then you have a second pulley that's attached to the weight that you plan on moving. You tie one end of your line off onto the beam or even onto that that first pulley that we're talking about. Feed the line down through the pulley that's attached to the weight. Feed that line up through the pulley that's attached to the beam, and then you finally hold the other end. You pull down, and now the weight has been reduced the amount of force you need, or at least the perceivable weight you feel. The amount of force you need to move that weight has been reduced a half. But you have to move twice as you have to pull twice as far, twice as much rope to move it the distance that you wanted to go. So, in other words, if you want the symmetry of physics is beautiful. Yeah, so if you want to have lifted that two feet, you have to pull four feet of rope, all right, But you could add more pulleys and this would decrease the amount of force further while increasing the amount of distance more. You would actually have to have longer rope obviously, if you started to add lots and lots of of pulleys and you had a full block and tackle system. But this would allow you to move incredible weights using a relatively small amount of force. You would just have to be willing to pull lots of rope in order to do it. Or line all, all of the sailors who listen are just singing, there's such a Rube saying rope. I guess maybe they don't like the word rope. It's it's line. It's not rope, it's line on a ship. Yeah, I spent a little, tiny, tiny amount of time on a ship and I got I got corrected so many times. Well, we should have a face off between geometris and geometrs, geometricians and geometris, geomet geometrists or I think, Yeah, I think of geometry as trickery, so I I my vote goes to the geometric stars, geometry teachers, and sailors, and they can argue about lines. I knew some geometry teachers who could definitely take on some sailors in their time. Okay, let's let's do another one. All right, sure, what what do you want to do? The screw? The simple machine? Right, Yes, I am so, if I'm not mistaken. The screw is basically just an inclined plane in a particular configuration. Yeah, it's an inclined plane that is wrapped around the core of something like a like a shaft. So you take a shaft, you put an inclined plane, and you spiral it around the shaft and you get a screw and uh, screws. Can it's a tiny circular ramp. Yeah, And that circular part is what's really important, because it means that if you apply a rotational force to the screw, it provides a linear force along the length of the shaft that is greater than the force you used to turn the screw in the first place. Uh. This, of course is dependent upon the pitch. The pitch. The pitch the pitch and screws is The description is that it's the distance between the treads. So the the sections of the ramp, the closer together they are, the greater the ideal mechanical advantage. And the reason is the mechanical advantages dependent upon the length of the inclined plane the ramp to the length of the shaft. So if the treads are closer together, that means if you were to untwirl this, the ramp would be much much, much longer because the cram more of it along the length of the screw. Yeah, that makes sense. So yeah, that's like having that longer, slower gradient of ramp up to the summit, right exactly. Yeah, So it's interesting to think of it that way. But yeah, the treads are closer together, it's going to exert a greater force when you turn this this. These of course, have been really useful in lots of different uh applications, every thing from you know, just securing something to the wall, for example, because it has a great holding force that way to lifting things. Our comedies, screw was a way of drawing water out, which was kind of cool. Um. You know, it's it's an interesting simple machine, and it's something that if you were to look at, like you go to a hardware store and you look at a bunch of screws, you wouldn't necessarily think this is a machine, right. You think of it as a tool or or you know, just something that you need. But it actually is one of the simple machines. And only is it one of the simple machines, but like we're pointing out, it's a simple machine that's made up of an even simpler machine, which is kind of cool. Um. Yeah, it's an interesting, uh piece of machinery, if you if you will. And the earliest evidence of screws come from Greece, uh so they were actually one of the later simple machines to arrive on the scene. And the grand scheme of things had had a screwed. Yeah. Yeah, that was the one that drew water up. Yeah, the water the water screwe. Yep, it's really cool. If you've never seen any illustrations of that, you should look it up. Our commedie screw is pretty cool. I think we talked about it, and we did a tech Stuff podcast ages ago about our comedes, and I'm pretty sure we talked about our commedity screw. We we spent a lot of that time. That was a Cris Pallette episode, and we've been a lot of that time talking about some of the crazy inventions attributed to our commedes, perhaps apocryphal e Like the claw that reaches out of the city walls and grab ships. That was one of them. Yeah. Alright, so let's talk about the last of the simple machines. Yet another application of the ramp, right, Yeah, this is the wedge. So a wedge is essentially two inclined ramps that are against each other to create this wedge shape. And uh, they can be used to do a couple of different things. They can be driven beneath a weight to lift it up. So this would be you know a wedge that you would you would put the end of it under the weight, and you would apply force to the the flat end of the wedge, the back end, the butt end of it, and that would end up pushing the weight upward because of the the design of the wedge, or you could use it to be destructive. So Jonathan, I have a question for you. Ask away, Joe, have you ever split wood with a mall? I want split wood with Darth mall? No, I'm serious now, no lightsaber jokes. Have you ever split wood with a mall? I have not. I've only split wood with axes, which are not necessarily easy tools to use for that purpose. Well, a splitting mall is. It's hard work, but man, it is a really satisfying feeling. So imagine it's sort of like an ax. Uh. It is a sort of a combination of an ax and a sledge hammer. If you can imagine that it's a long handle and then at the end of the handle you have this bulky heavy head that is basically a wedge on one end and then a sledge hammer on the other. Just I think to increase the weight basically, and the wedge doesn't even necessarily have to be that sharp. I think it usually isn't the one I used wasn't very sharp, but because of the weight, it was a one hit splitter. So you'd put a log segment out and you'd hit it once and it would just cleave apart, which is pretty impressive. Yeah. Oh man, it it felt good to do, but it got tiring after a while. Yeah. And see you can see that there's some like within the mall. There are two machines here at work. Right, You've got the lever as far as the handle, that's what's allowing you to apply leverage when you're doing your swing, and then you have the wedge, which is doing the actual splitting. So the wedge, what it's doing is it's applying that downward force and changing the direction of that forced to outward. Yeah, so that's why you when you hit the log, that outward force splits the log apart. And it's really cool. I tried doing the same thing with access, which you can do, but it takes more effort, yeah, because the axe head probably just doesn't heavy enough that. Yeah, it's you know, you're using, so you have to take up some of the force that normally would have been taken care of by the the tool itself. It's pretty cool. I've never done that now. Uh, it's yeah, give it a shot sometimes. All right, next time I'm out in the woods and I'm just thinking, you know what I need to do, It's just split get your hands on the mall. You know, my family actually called it a maddic. I had to look it up and figure out that I was wrong about what a mattock was. A matic is a thing with a differently oriented head. It's kind of like a pick axe got you. But that was just how your family referred to it. It was a mall. I have determined now. So yeah, these are um, that's the that's the last of the six simple ones. But then there are also other machines that we can talk about, compound machines. I mentioned those earlier. These are the machines that combined two or more simple ones. Ship's Home is one of the examples we already talked about. Wheelbarrow was another one we talked about. Scissors would be a great example because with scissors, you've got a pair of wedges. Uh, those would be the blades of the scissors, and you have a lever. The handle that you hold would be a lever. The fulcrum would be the center that that binds them together. Uh, and so that's what allows you to use scissors. Compound machines have more moving parts than simple machines, but that's not necessarily a good thing overall, because the more parts you have, the more you have to overcome friction. If you add lots and lots of different parts, that friction could be very difficult to overcome and it could end up generating a lot of heat, which is why very complex machines like a car engine require coolens and lubricants in order for them to continue to work properly. Um. That means there's also a loss and efficiency. However, the compound machines have greater mechanical advantage. You actually multiply the problem. You multiply the mechanical advantage of each of the individ dual um simple machines within the compound machine to determine what its mechanical advantages. So as long as every single simple machine in your compound machine has that ideal mechanical advantage of greater than one, the more you add, the greater mechanical advantage the compound machine has. And thus we get to the room Goldberg device. Yeah, what what's it? Has like a goldfish that operates a magnifying glass that burns a rope and yeah, exactly, and then you get an okay go video out of it. Not all those would be simple machines, I don't think the magnifying glass, but even some of those would be compound machines. That would be a collection of simple machines. But there you go. That's the collection of simple machines and what they do and why they're important. Um, it's it was fun to look back at this, even though, like again, this is something that any of our listeners who are still in school, they may be rolling their eyes for the whole thing because they're thinking they've already learned all this stuff and that is repetitive. But for those of us who graduated a long time ago, and perhaps I have not kept up with physics the way we might have, you know, wanted to. I loved physics when I was a kid. It was one of my favorite favorite subjects in school. I wish I had appreciated science more when I was in school. I didn't. I didn't really come to love science until after I was out of school, and then I wished I could go back and and treat it with the respect it deserves. Out of all the sciences, uh, classical physics was the one that appealed to me most because it was the one that made sense to me, because it was it was the physics of the world that I could observe around me, and I loved it. I just I understood it and I took to it. Not so much with the biology and chemistry as it turns out. I mean, I did well, but they were harder. They were harder to learn for me. That wraps up the classic episode on the six Simple machines. I've seen so many cartoons that explained those and I love them so much. Uh, really fascinating stuff to me, like to think back on how these underlies so many machines today. I mean, at least the mechanical ones. Once you start getting into digital, it's a whole different ball game. But I hope you found that interesting. If you have suggestions for topics I should cover for future episodes of tech Stuff, please reach out to me. The best way to do that is on Twitter. To handle for the show is text stuff H s W and I'll talk to you again really soon. Text Stuff is an I heart radio production. For more podcasts from my heart Radio, visit the i heart Radio app, Apple podcasts, or wherever you listen to your favorite shows.