Scaling, scaling. And we talk about scaling, you know, we aint talking about the distinction between area and volume. You guys know what area is . Area is measured in square centimeter, square meter, Something Like that, yeah. You know what volume is . Cubic meters, size. Got a question for you. See the water in here . Im gonna pull the water in this vessel into this one. And what youre gonna do here you make an estimate. When i pour the water in, itll come to about halfway. No. Itll come to probably less than halfway. No. No. No. Itll probably come to more than halfway. More than halfway. Check your neighbors. See what your neighbor be estimating. Okay. Gang, here we go. Appreciably more than halfway, is that not amazing . You know whats going on here, gang . Volume. Guess what geometrical shape has the minimum area. A sphere, a sphere. Thats why the sun and stars are round. Thats why the earth is round. Its pulled in to the least surface areas. And a sphere has a very, very small volume compared to its i mean a small area area. Thats compared to its volume. Now, this volume and this volume are one and the same. Right. It turns out, with Little Grade School kids they cant see that. Theres a certain stage of development that one must go to before they can deal we can deal with these ideas, cant we, right . Okay. We know the volumes are the same. In fact, i get pour it right back and say, is it gonna overflow again . No. Now that your seeing the answer, what are you gonna say . No. Maybe. But if you didnt see it before, what would you say . No. Yes. Isnt that something . So why is it that this looks to be so much more than this . Size. Size. Because this has considerably more area. The number of square centimeters of red you see here are much more than the number of square centimeters that you see here. So the area, volume different. And here, were kinda judging the volume by what we see, but all you can see is the area, except that you can see through it. Isnt that kinda neat . And some really interesting things happen when you scale things up. You know, as you scale things up like a plant starts to grow, as it gets bigger and bigger, it gets heavier and heavier, right . Theres got more surface area, yeah . When it gets twice as heavy, does it have twice the leaf area . Leaf area . And it turns out, answer begins with an n. No. All right, begins with the n and ends with the o. Try it. No. No. Andand thats what were gonna talk about, today. Okay. Weve all, we have all am i being presumptuous in saying this . We all have, as little kids, have looked at little ants. We take the time to do that when we were kids. We look at little ants crawling around and lifting little boulders, boulders compared to their own size, yeah . And we marvel at how strong the ants are. Is there anyone in here who did not as a child stop and look at the ants and see them carrying little chunks of rock, and who did not marvel about how strong they seem to be . Who . Huh. [laughter] what . Deprived childhood is well, most of us have looked at such things, right . Let me ask you a question. How strong you suppose that ant is . Strong or strongstrong . Strongstrong. Compared to for sure . Compared to what . Good point. Lets suppose this happens, gang. An elephant walks to this door. The elephant is gonna start lifting up logs. A door over here, an ant walks through thats just as big as the elephant, a super ant. This super ant is been [makes sounds] i dont know how its been done, Science Fiction, okay . Scaled up. And it scaled up, so, that ant [makes sounds] the same size as the elephant. Now, theyre gonna have a contest to see who can lift a greater load. Who are you gonna be betting on . Elephant. Ants. Check your neighbor. Is there anyone in here says, honey, the ant cant even do push ups. The elephant is the one thats the strongest. Show of hands. All right. These are my people. These are the people who have read the book. The rest of you guys come in for a free lunch today, right . Whats that thing all about, yeah . Come on. That ant couldnt make it. The legs are too skinny. Yeah, i see. Why ants got skinny leg . Ever see a daddy longlegs . Ever see a rhinoceros, an elephant . Humongous legs, very, very thick. Why . Because as things get scaled up, scaled up and scaled up, it turns out the thickness of the leg doesnt catch up with the bulk of the body. Lets see if we can understand these ideas with the simple example. Heres a cube. If i make this cube twice as big. How much heavier will it be . Are we gonna say, what do you mean by twice as big . This is what i mean, twice as tall, twice as wide and twice as thick. How heavy will it be compared to now . Check your neighbors. Heres one twice as big, gang. Twice as big has twice as much weight . No. Everyone who say that, stand up so the rest of us see what you look like. Really . The same guy. [laughter] this guy has aokay. No, it turned out this can be how much heavier . Four. Eight. Eight times. Look, 1, 2, 3, 4, 5, 6, oh, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 12 times as heavier, yes. [laughter] just im counting the same one twice, yeah. But 1 cube 2, 3, 4, 5, 6, 7, then we have to assume that theres one down back there we cant see, yeah. Its eight times as much. So let me ask you a question. Lets suppose somebody walks in the door, six feet tall, 200 pounds athlete. Take that person, put him in a Science Fiction type machine, push the button [makes sounds] scaled up, 12 tall. Shoulders twice as wide, chest twice as deep, twice as big. He dont weigh 200 pounds anymore. Now, he weighs . 16. 800. Check the neighbor. How much would he get weighed in . How many say 1,600 pounds . Thats right, thats right, see. cause if this block here weighs two. Whats this block weigh . Eight times two. Now, i have a block here, but it would work with the person. It would work with all the ideas were gonna talk about today will work with any shape. Its just that by working with little cubes, its easier to get the principle. Now, how strong a person is has to do with how thick their bones are. That person whose 1,600 pounds, if he jump from here to the floor hell break his legs. It might be even jumping from a high cliff stone to the ground, hell break his legs. You know why . Are his legs thicker . Yeah. Yup. Theyre twice as thick. Now, when its twice as thick, okay, the Cross Sectional area, lets suppose this is a leg bone. The Cross Sectional area is like here, huh. Whats the Cross Sectional area of this piece over here . Four times as much. Okay. So we have the Cross Sectional area here of one, and we double it up, its four. Lets look at the weight, and weight and volume are proportional. To say these two blocks have twice the volume as one block and they have twice the weight. And over here we have what . Heres a block scale though. Now a block two by two by two. Look, this is eight times as heavy cause its eight times the volume. But the crosssectional area is four. So what do we do . That fellows legs, thisor arms, okay, the thicknothe muscles have to do with the crosssectional area. How many tendon do you have there . How manynot tendons but how many little muscles pulling down, yeah . The crosssectional area. And the crosssectional here is one and the weight. Crosssectional area is one to one. But when you double the size of something, the crosssectional area goes up to four but the weight goes up to. Eight. Eight. And 4 8, thats like 1 2. Let me ask you a question, what if you took that cube and you triple the size . Triple the height, triple the width, triple the depth, boom. What its gonna be . Now, its gonna be Something Like this. Can you kind of see that . Can you count em up . Then we get out. The cross section, area. Wheres the crosssectional area now . Its sliced through that. Nine. Nine. Now, its gonna be heres gonna be nine. And whats the weights gonna be . 27. 27. 27, gang. Can you count em up . Three, 3, 3, 3. Nine after nine, i see. And what do we got here . 1 3. 1 3. As we keep going up and up and up, it turns out that the weight gets a lot bigger than a Cross Sectional area. And you know what, the strength, the strength has to do with the crosssectional area. So the strengthtoweight ratio goes down as things get bigger and bigger. So if youre gonna scale that person up, and youre gonna make it in this world, hes gonna have disproportionately thick legs, much thicker legs than , say, hes in proportion to his body than, i say, at six feet. If you look at the animals, the largest, the heaviest animals have disproportionately thick bones. Look at here, a skeleton of a cat and a skeleton of an elephant. Scales so that they both have about the same size. Look at the size of the bones on the elephants legs compared to the cats legs. This is an illustration from a book by steve vogel. Its called, lifes devices the physical world of plants and animals. And so, sure enough, elephants have thicker legs in proportion to their size than, say, daddy longlegs or any other kind of insect. cause as these things get bigger and bigger, the strength doesnt keep up with the weight, so you got to compensate and make extra thick legs. We are really designed for the environment which we live, gang. Thats the message. You know, you see the king kong movies . King kong all scaled up like that . No way. King kong scaled up in proportion wouldnt be able to stand up. Hed be crushed by his own weight. Even whales have a hard time. Whales are just too darn big. And so whalesdo you know what happens to a whale when he gets beached . [makes sound] pretty well crushed by its own weight. So it has to stay in the water thatsovertime. Large creatures not so well designed for the world we live in. I can take a toothpick, and i can hold a toothpick between my fingers. You cant see the sag. The tiny sag thats there, you cant see, its not noticeable. But take that same toothpick and scale it up. Lets suppose you make it 10 times bigger. 10 times longer, 10 times thicker, 10 times wider . Is it gonna be heavier . No. 10 times as heavy . No. No. It turns out the volume goes up as the cube, so its 10 times 10 times 10. It will be a thousand times as heavy. How about the crosssectional area, the strength . That will go up as the square, 10 times 10, so it would be 100 times stronger. But carrying 1,000 times the weight, gang, you would see it sag noticeably. Thats why people who make models of bridges out of toothpicks, and they think all they got to do is make a bigger one out of, you know, a bigger materials, and it turns out they crush. It turns out the engineers get paid a lot of money to do things like make skyscrapers. You know, the Golden Gate Bridge . When the Golden Gate Bridge was being built, being planned, a lot of people who knew about this sort of thing said, no way, youre not gonna make a bridge that big. You can make a little model. But if you scale it up, the strengthtoweight ratio is gonna kill you. And it turned out they were able to do it anyway. And even some of the skyscrapers were built today are really marvels of engineering, because theyre having a deal with this idea of the strengthtoweight ratio. Any questions . I wanna talk about the idea of the total area, the total area of something. Whats the total area of this cube . Lets call this one unit. Then the area, the total area is one here, two, three, four. Can you see theres six sides, okay . So i have a total area here of six. So far, ive been talking about crosssectional area, just the area through here. Lets talk about the total area. The total areatoweight or to volume. Lets call it volume, areatovolume. Okay. Here its six to one. Why do i put six to one over here for . Because theres six square units compared to one cubic unit, all right . The volume of this, this times this times this, one cubic unit. The area is one times one, but you got six of them, so six. So its six to one. Now, what happens to the ratio of surface area to volume as you scale up . The consequences of that are very important. It turns out theres a mismatch, because as you scale up, the area is gonna increase as the square of the increase, but the volume increases as to what . Cube. Cube. Let me show you what i mean. Over here, ive made my thing twice the size, so my area now is gonna be what . Its gonna be 4 on any side times 6 is 24. When i doubled it up, ive got a total area of 24 square units. Do you see that . Counting all the sides, yeah . Whats the volume . Eight. Eight. Whats my ratio 3 1. Of area to volume . 3 1. My ratio is 3 1. My ratio for the small thing was 6 1. A lot more area compared to volume over here, less area compared to volume. What happens over here . Whats my total area for a three by three by three . 54. 54. Every one side is nine. Nine sixes. 54. 54 total area, unit area. Whats my unit volume . 27. 27. 27. 27 under 54 . Two over one. Calculator . Two to one. Two over one. Ive already looked it up, let me tell you. Its two to one, okay . The message is this, gang, as things scale up, up, up in size, the ratio of area to volume goes down, down, down, down, down. That means Little Things have more skin, more surface compared to the volume than big things. Every cook kind of knows when theyre gonna buy some potatoes, theyre on to this. Lets supposed youre gonna buy some potatoes and youre gonna peel some potatoes and cook up some potatoes on and youre gonna have friends over, okay . Mashed potatoes, no skins. Say youre gonna peel them all. Now, someone says and he find out that you want to get two kilograms of potatoes. Now, should you get two kilograms of big potatoes or two kilograms of little potatoes to feed the most people . How about you get two kilograms of little potatoes . The Little Cherry ones, the little cute ones. Then you peel those things, okay . You got a pile of peelings like this, yeah . How about you peel the big potatoes . [makes sounds] a little pile. So you got more potato per kilogram if you get the big ones after you get through peeling. Lets supposed your mother say, hey, i want you to peel something for me. What i got to peel, ma . You just got to peel a pound of fruit. Okay, then i can go out . Yeah, you can go out after that. Whats the fruit, ma . Raisins. [laughter] and you will spend your whole weekend peeling on those raisins, okay . Theyre little, theres awful lot of skin per pound, per kilograms, do you know what im saying . And Something Big. A little bit of skin per kilogram. So Little Things have more surface area compared to their weight, compared to their volume than big things. Do you ever notice that before . You got a glass, you got an ice, you got a drink, you wanna cool it. Someone says, put an ice cube. Someone else said, no, crush the ice cube up and then put it in. Itll make the drink cool faster if you crushed it up. Someone else say, its the same amount of ice either way. It makes no difference. You say person next to you said whats the answer, gang . How many people say, its the same amount. Hey, its gonna cool. Its the same way, either way. Make no difference. Hey, wait a minute, though. Hey, wait a minute. No, if you crush the ice, you gotta get a whole a lot of little pieces. And a whole a lot of little pieces will have more combined area, than a big piece. Crush it up. Crush it up. How many people say, yeah . Yey. And you got a great big log and you wanna light it with a match. Someone says, leave it in a great big log, itll last longer, so you have it all night. So you take your match what are you doing with a log . You shave off little pieces . And when you get little pieces, why will it catch fire quicker . More surface area. More surface area. More surface area. Yeah. You got some steel wool sitting in your sink. And the steel wool gets rusted out, in one month its gone. But the same hunk of steel from which it was made will stay there for a year. How come the steel wool gets rusty and rusts away and the hunk of steel like more what . Sa, sa. Surface area. Yeah. You gonna cook some french fries. Yeah, but the skinny ones, its gonna cook faster than big fat ones . Why . More surface area. More surface area. Youre making some meatballs. Kinda taking a long time to cook, so you flatten them out so theres more surface area. It cook faster . Yeah. Yeah. Yeah. It cook faster. Big peoplelee . All right. Can ants breathe through their skin . Say again. I think the ants breathe through their skin. Ants . Ants . Insects breathe through their skin. They got a lot of skin or a little skin compared to that that which they have to nourish. Begin with the l. A lot. A lot. Okay . Human beings cant do that. You know why . Were too big. So we have to have another system all together. So weve developed what . An awful lot of surface area. Its all inside. Take your lungs, gang, and flatten them out. Cover the rug of all this room and two other rooms too. You have enormous surface area on your lungs. All those little many folds, and see you make up for that too. How about the intestines of a being . Whats the intestines of a worm look like . Straight line too. From mouth to back. Huh . How about the intestines of Something Big like a human being . Many, many folds. You know why . cause as you get bigger and bigger, you got more and more to nourish and you got to get more and more surface area. You think so . Okay. Gets bigger and bigger, right . Lets suppose the living cell gets double the size. Someone say, oh, double the size and it got four times as much skin. But four times as much skin feeding how much more cell . Eight times as much cell. So its teeth grow and grow. And, honey, the skin dont keep up with the cell thats got to be fed. So you know what its gonna do . Its gonna die or divide. Guess what it do . Divides. It divides. Arent you glad that they divide, cause it cant keep grow and growing and growing. It will die inside, yeah . And so it divides. And thats why cells divide. Or i could say why they do. But if they dont, they die. Cells have to divide and keep to getwhy . Because the skin, compared to volume, keeps getting less and less as it gets big, big, big. So, its gonna get break into little pieces, smaller pieces. Kinda neat, huh . Kinda relevant, yeah . It turns out that Little Things have more skin than big things . How about Little People . Little people had more skin than big people . When i was a kid, they always used to call me skinny. You know why they called me skinny . Looking back, i can see why. cause i had like like i told you guys before, i weighed about 85 pounds in freshman in high school. And all my friends weighed over a hundred and youre skinny. In fact, i used to find out that walking in the cold streets of boston, i always used to seek the sunny side in the winter. After the getting the sun to keep warm. My friends big, healthy friends, they could walk in the shade. Say hewitt, how come you walk in the sun . Someone says cause his skinny. Thats true. Because i was skinny. You know what that means, skinny . Too much skin compared to my body. Where do you radiate your heat, gang . Through your what . Begin with sk. Skin. Skin. Okay . Through your surface. Youre radiating all the time. Youre losing heat. Youre warmer than the environment. And so youre radiating off heat all the time. Who radiates off heat the most, the one with most skin or the mostone of the least skin . The one with the most skin. And the most skin per body weight are skinny people or smaller people. Big people dont radiate so much compared to the body weight. Little things like little animals like rats and mice, theyre little, yeah . They got a lot of skin compared to their weight. And so their radiating heat disproportionately compared to us. Elephants hardly at all, but a little mouse, a little shrew, you know there are shrews that have to can eat almost constantly to stay alive, just to generate the heat to stay warm. If they run out of food, they eat each other. And like a mouse eats almost its weight every day just to stay alive. And another thing, too, you wont find mice up high in the mountains where its cold. They cant make it. They simply cant make it. They have to eat food faster than they could get it. And so you find even birds, little birds, tiny birds. You see birds, oh, what a bird doing all the time . Eating, eating, eating, eating. Come on, you had your dinner. You had your lunch, how come hes still eating . Birds all the time eating, why . cause they got a lot of skin. Theyre radiating heat like mad compared to their size. You got a pet bird and you dont feed it, letoh, dont feed it some day, it will probably die that night. So Little Things have to eat a disproportionate amount of food just to keep up with what . The fact they have more skin, more radiating area. How about elephant . Give an elephant a handful of peanuts, its all set for three days. Okay . The elephants all inside. Elephant doesnt have very much skin compared to its body weight. How come snakes can go a year without eating . Well, snakes now. Snakes are coldblooded too, though, yeah . Yeah. And now, so coldblooded things, i think, they dont have to contend with this thing. They dont to eat to stay warm. Theyre not warm anyway. So snake or reptile or things like that dont have this problem. I should have prefaced this as mammals or warmblooded creatures, creatures that are warmer within the environment, where they get that warmth . Thats energy, honey. And wheres that energy come from . Its got to come from something. Itll dietheyll digest themselves and lose weight, or theyll have to digest nutrients from the outside . So warmblooded creatures are the ones that really have this problem. They cant they cant get too small without having to eat enormous amounts of food. The hummingbird. [whistles] honey, hummingbird really, really, got to keep fueled up all the time. Its so small. Its warmblooded. The hummingbird got to get a lot of food. If you thinkget the nectar very high energy, high sugar content, yeah . But the hummingbird, they got to go from station to station without running out, die quickly without the food. How about the elephants, gang . You be knowing why the elephants got big ears . What if you play a trick in the elephant and cut off its ears . What its gonna do . Its gonna roast to death. Right . Elephants doesnt have very much, much surface area. And the elephants in the warm country, the elephants got to radiate off the energy, okay . Hows it gonna to do it . They dont have enough skin. It puts up more skin. You see its eyesthose ears. Those ears on a hot day, those ears come out. On the cold days, slap against the body, yeah . On a hot day, they come up theyre radiating surfaces. Theyre radiating they increased the area of the elephant so it can make up for that area it doesnt have. So big things dont have as much skin as Little Things compared to the body weight. Why do you chew food . Why it [makes sounds] likeyour fiends do it. Take a hamburger its gone in one bite, okay . [laughter] you chew the food to make smaller pieces. Smaller pieces so you can digest it easily, more easily, more surface area, increases surface area. Lets talk about falling things. You guys know when your pet hamster falls off the roof . Pet hamsters, okay. Your pet mouse falls off the top of the tall roof once a way, its okay. How about a horse . [laughter] splash, okay. Or human being crunched, okay . But Little Things, Little Things can fall great distances without hurting themselves. I wonder they have anything to do with what were talking about today. Yeah. If youe gonna jump from an airplane and you wanna live, you increase your surface area by you you get yourself a parachute. And you get that parachute and you increase your area, yeah . Does a mouse have to do that . Does an insect have does an ant have to do that . Honey, an ant is a parachute. An ant got so much area compared to its weight. Its [makes sounds] float and walk away, okay . So it turns out that Little Things have the advantage when they fall, because theyll reach their terminal velocity very quickly. Little things thats because they have a lot of surface area compared to their weight. Lets talk about terminal velocities. I got here some coffee filters, gang. I got two coffee filters. These will reach their terminal velocity very quickly. Watch this. Thats strange. They fell at the same time. Thats not strange at all. They both have the same amount of weight and they both have the same amount of air resistance. What if i make this one twice as heavy by putting the two together . Which one will hit the ground first . The heavier one. Did you see that . The heavier one because it has greater weight compared to its air resistance, okay . Now, heres the thing we got to look at. Theres the weight and theres the resistance. When these things fall, they reached their terminal velocity very, very quickly. Now, that resistance depends how fast its going. Maybe that resistance is proportional to the speed. If it is, if its directly proportional to the speed, then that means the distance something falls remember the distance is speed times time . That would mean that this would be proportional to resistance, this would be proportional to the weight. If the distance something falls to be proportional to the weight multiplied by the time. If thats true, that means something twice as heavy will fall twice as far in the same time. Lets see if thats true. Ted, can i have your help . Ive got a twometer stick here, gang. Ted, could you hold that twometer stick up . This is ted barnstorm, ta. [laughter] and what im gonna do is im gonna hold this one up here, two meters high, and this one meter high, and im gonna drop them at the same time. If the resistance is proportional to velocity, theyll hit the ground at the same time because this one will fall twice as far as this, okay . Lets try it and see. They did not hit at the same time. So hypothesis, no good. But lets suppose the resistance is compared stay right there, ted its compared to the velocity square . All right . If its proportional to the velocity square, then that means velocity square proportional to resistance proportional to the weight that means the velocity would be proportional to the square root of the weight. Can you see that . If thats true, then the distance something falls would be equal to the square root of the weight. So if i had something twice as heavy, that greater distance it falls will be proportional to twice the square root of the weight times the time. But thats proportional to and this is that. So if its true that the resistance is proportional to speed square, then the distance one falls is going to be equal to square root of two times the weight. You know the square root of two is, anyone . 1. 4. It turns out to be 1. 414, okay, times the little distance. If thats true, if i hold this thing up 1. 4 times higher than this, they should hit the ground at the same time. Shall we try it . Ive got this marked off. So this distance here is d, and up here turns out to be 1. 4 times higher than d. So im gonna put the twice as heavy one up here and this down here and drop them, and see if they hit at the same time. Ready, mark, set, go. Did you see that . At the same time. Lets try it one more time. Do it on this side. Do it on both sides. Okay. Oh, the heavy one on top, and the light one with the mark right here. Okay, ready. One, two, three. See that . Same time. This ball here has twice the diameter of this one. This is twice as high off the table. Twice the diameter, that means it has eight times the weight, okay . This one here has eight times as much weight but four times as much area. So whats the ratio . Two weights to one area. The same ratio we had over here. I should be able to drop this with one ball, one unit high, the other 1. 4 unit high. And when i do that, though watch this, gang. They dont fall together. You know why . Because they didnt reach their terminal velocities. The balls really are too heavy. So what i could do is i get lighter balls where it reached the terminal velocity right away. When i drop this thing here, it didnt have to go very far at all before reaches tv, maybe accelerate it for about a centimeter, then its tv all the way down. So you know what im saying . But these things will accelerate all the way to the floor. But if i put these in a more viscous medium, then it wonaccelerate but by a tiny, tiny bit. And we can do that with this container of water. Ted. Ted and i have been playing around with this a day before yesterday. So what we got here now is we got a couple of spheres, and one is twice the diameter of the other. It means it weighs eight times as much, and its got a weightarea ratio of 2 1. So when i drop these two things both at the same time, of course, the heavy one will hit first. You see that . But what im gonna do [laughter] im not gonna drop them. I take this [laughter] you guys are wondering, yeah . Yeah. Ted was doing that yesterday because his arm is he got long arms. So wehe had this little thing made out. Isnt that kinda neat, see . Oh, yeah. [laughter] heres what were gonna do. This is teds idea, by the way. So what were gonna do, im gonna put this up here. Oh, no, no. Its my idea to screw it up, okay . [laughter] so ill put the bottom this one here. Oh, what weve done is weve measured this off. From here to here is d. And from here to here is 1. 4 times d. This is a little bit longer, of course, you can see. And its at 1. 4, same thing weve got with the cops. So lets try it now. Right there. There we go. Oh. Thats why we get this oops, more water. Oh. Oh, weve got some more water. Its goodon that, yeah . [laughter] okay, here we go, gang. The little one here. [laughter] big one here. And im gonna flip this off to the side and see if you dont see them both fall at the same yehe yehey. Huh . Isnt that nice . Okay . So heavy things will fall faster or the same as light things . Faster. Faster. These fell at the same time because one, of course, was higher. One had to go up a greater distance. Aint that nice . Okay. Yeah, do it one more time. Oh, one more time. Yeah. Why not . If these were a couple of dead fish and the couple of dead fish were going down, which dead fish would get to the bottom first, the big one or the little one . The big one. The big one. The big one will fall faster, yeah . Yeah. Do you have any friends that swim . Do you have any friends that are like competition swimmers . Do you know any competition swimmers who are look at that. Do you know any competition swimmers who are small . Will this effect of scaling be useful or nonuseful to a small swimmer . Two people fall off a cliff in a vacuum, big person, small person. Which one hits the ground first . The same. Now, two people fall off a cliff in the air, one is heavy, one is light. Which one hits the ground . The heavy. I take these two balls here, one is heavy, one is light. Which one went faster through the water . Heavy. Heavy. And the light one, honey, got to do some tricks or something to keep up with the heavy one. Thats right. So big boats usually go faster than the small boats. The big fish swim smarter than fast fish. The small fish [laughter] you know a big fish will open up their mouth and just go, right . The little fish cant keep up. The Little Things have more resistance compared to their strength. The effects of scaling. Yehey. [music] you are bonkers cause iron doesnt float. People make boats out of wood. Well, heres this clay, and it has the same weight. Watch this. Oh, yuck. [laughter] yucko. Yeah, we got it now, gang. Isnt that nice . Now its being held up by what . Your fingers. My fingers. You get the idea. Conctration of force is pressure. So lets talk about that, gang. Pressure, definition. Screwed up. I dont wanna talk about pressure. I wanna talk about density first. You guys, can you come in on wednesday . [laughter] how do wfind the center of gravity of Different Things . Well, the books easy. How about Something Like this . Theres a way. And the way is very easy. Let me show you. All i gotta do is suspend it. Suspend it by that point. Guess where the center of gravity is, gang . Its somewhere beneath this line, okay . Over here, somewhere in here. Now, let me try this again, gang. Troy, i think our board is insufficient. Let me try this again. Let me hold it from here, gang. The center of gravity is somewhere along there. And i can see if thats true by seeing if it will balance. And it does. So its somewhere along there where along there . I can hang it by another point and find out that its now, troy, the center of gravity of this board is within the board. That blows everything, gang. I dont know what to do. Yeah, the boards too fat. Look at the globe here. In the summertime, amsterdam is way up here, okay . Now, lets suppose we have an imaginary line right in here about where darkness is, okay . Everything to this side here is dark, cause lets suppose the sun is coming in this way, okay . Sunlight is coming in. Well, lets look at amsterdam way up here. Yeah, right here, okay . First of all, the sun comes up. Here they are. Day, day, day, day, day, day, day, day, day, day, day, day, day, day, day, day, night, night, night, night, night, night, night, day, day, day, day, day, day. Most of the time, theyre in the sunlight. The sun come right here. Mostive got this wrong. Ive got this wrong, gang. Ive been doing it. In fact, when i get over here and started halfway, what . Did you see i screwed up . I screwed up. What was my screw up . Check the neighbor and see how hewitt screwed up. [laughter] how did hewitt screw up . Come on, check the neighbor. How many are saying, it looked all right to me. [laughter] come on. How did i screw up . You actually turned it over. Yeah. Turned it over. Well, you gotta well, for television okay, its got 24 times as much ea to feedtsf. But whats wrong with that, gang . Twentyfour times as much area is feeding how much more cell . 1, 2, 3, 4, 5, 6, 7, 8, eight times. Oops. That was 24. Yeah, it mixed up. Yeah, eight times much. Four times. Oh, now, i mixed up, gang. Im getting mixed up. It is four times as much total area, because 24 is four times six. Four tes six, thats why i screwed up. What im gonna do . What im gonna do . How do we start that . Thanks for bailing me out again, lee. What are we talking about im selfconscious when this camera is on me. The cell is getting bigger and bigger. Huh . The cell is getting bigger and bigger. Oh, yeah. [laughter] you guys get freaked out with this thing looking atou how about me, yeah . [laughter] the living cell gets bigger and bigger, right . Lets suppose the living cell gets double the size. Slight, uhhuh what dwe got here, g [laughter] what do we got here . Trouble. Ive got a tablecloth. Ive got a tablecloth with no lip, okay . No. Watch this. Those dishes are essentially at rest, arent they . Heres something for you to do this weekend when you finally get invited to your friends house for dinner, okay . And the friend wants to know, what are you doing, what are you doing at school . You can kind of show him this, right . You dont wanna try this at your own house, not with your own dishes, okay . You might messbut you try them at your friends house. How about this, gang . Whats gonna happen if i pull this thing very, very quickly, huh . Whats gonna happen . Lets try it. A one, a two, a three. And there you see newtons law flawlessly executed. Distincon between that distinction between weight and mass, i can kind of show you that kind of neatly with this device. What im gonna do is take this heavy ball heavy ball or massive ball . Both. Yes. Both, yeah. See, im gonna take this ball. Its got a lot of mass, also has a lot of weight, okay . And what im gonna do, im gonna take one of these strings in the bottom. You see ill try different trials here. And im gonna pull, pull, pull. Im gonna pull, pull, pull, pull, pull, pull, until one of these strings, either the bottom one or the top one, is gonna break. And what i want you to do is i want you to guess, hypothesize, which string, the top or the bottom will break with a gradual, gradual tension increased at the bottom . Check your neighbor. Okay, when i pull that very, ve slowly, gang, which string gonna break, top or bottom . Top. Top. Top one . How many say the top . Lets try it. [laughter] maybe newtons having a bad day. [laughter] you know what that might have been . That might have been a string before that we partially damaged. Yeah. Probably. Can we sta the tape. T withangle li that, doesnt it trave a greater distance than the one thats just falling vertically . So for them to hit the same time, it has to be going faster. The object has to be traveling faster. It turns out, if i jump off the lanai like this, ill step off like this. Ill step off like that. Ill hit at the same time in all places. Over here, ill be going faster, because i have a bigger speed like this. And that arrow is gonna be bigger than this and this. Id be faster, but ive gone a further distance. Right. Okay. And later on well talk about a neat, neat concept thatll tell you that down here, thewait a minute, i will not be going faster. Erase the tape. Lionel, thats wrong. It turns ill have the same speed here, here and here. No, i wont either. No, i wont either. Now, lionel, the tapes okay. Leave it going. Sorry. [laughter] i get a little mixed up. Do you guys get mixed up with this stuff . I mean, all the time, i get mixed up with elementary physics. So if you guys get mixed up, dont feelad. Im with you, all right . With this clip, im gonna sten the point here. Now, im gonna crank this again, okay . If you see a lightning bolt from here to here, if you see that, scouts honor, a in the course. If you dont see that, then you got to do your exams and study and da, da, da, da, okay . So lets try it now. [laughter] ive seen it. Scouts honor. Scouts honor. Never go back on a scouts honor. [laughter] oh, boy. [laughter] its almost as if theres a spark there, isnt there . [laughter] this is most unusual. I think i see try switching the other side. No. And, gang, i have no explanation for this. This is new to me. Cau put it on the other side . This shouldit should be less probable, though, but you see its got to leak from one to the other. I wonder if its because i didnt discharge it to begin with. Let me try something. Continuing to charge. Isnt that in a way yeah, it does. It turns out it does, yeah. But i couldyou crank it counter clockwise. Okay, watch this now. It shouldnt do. [laughter] that blows me out. That blows me out. This has never happened before. Ive never noticed and if t leaks ofthat point th ishould drift over here without havi tt snap, snap, snap, and its not happeng. Try towhen you put the two points on it, you turn it the other the way. Oh, well, i didnt mean to do that, but. See if it works now, but that maybe you should discharge it first. [laughter] oh my god. [laughter] i noticed everyone out there seems to be pretty happy today. [laughter] you seem to be pretty happy because you see the old fool up here making a damned fool of himself, right . You guyshould all be saying, oh, geeso we could eah, we can test to see whether things are true. If i bring a positivei bring a positive object nearby, shouldnt the positive object attract the negatives and pull the negatives from there . Mmhmm. And shouldnt the leads collapse . One of the nice things about science is you start to understand and see if you can predict things. And if you can, then it tells you that your theory probably is more likely correct than more likely wrong. Lets try that, gang. If this is more positive oh my god. [laughter] why does it still diverge more . That blows me away, gang. Is that coming together . Its getting me and more diversion. And it should collapse when i bring this over. Should. Wh do you mean it should . Its doing what it should. My explanation is just off, right . [laughter] look at that. Ive got nothingo im supposed to be teaching you guys electrostatics. Ive got nothing to say. In fact, probably everythi i say is just all canned crap. [laughter] because, honey, its just not doing. Lookt that. Ive got nothing to say. I could talk about coulombs law a litt bit, but i dont believe in it anymore. [laughter] lets continue as if everything were going smooth. Its called make believe. I thought science was all about making discoveries, expemental and we could continue with this, couldnt we . We could continue and maybe find something fundameal, but its not part of my act. [laughter] well, okay, lets move on, gang. I dont know. Someones gonna give me an explanation of whats happening here. And im gonna be very impressed. Who is going to be the one . In fact, that could be like a term project. What went wrong tonight . Whos goa say, hewitt, nothing we wrong at all. Hat happened was, da, da, da, da, da, da, da. What went wrong was your failu to be able to observe and interpret what happened to it. Da, da, da, da, da. Nature is not wrong, you is. Okay . Someone write it out, cause i am baled, gang. [music]