i've got a two-meter stick here, gang. ted, could you hold that two-meter stick up? this is ted barnstorm, ta. [laughter] and what i'm gonna do is i'm gonna hold this one up here, two meters high, and this one meter high, and i'm gonna drop them at the same time. if the resistance is proportional to velocity, they'll hit the ground at the same time because this one will fall twice as far as this, okay? let's try it and see. they did not hit at the same time. so hypothesis, no good. but let's suppose the resistance is compared-- stay right there, ted-- it's compared to the velocity square? all right? if it's 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 that's 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 that's proportional to-- and this is that. so if it's 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 that's 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? i've got this marked off.

so this distance here is d, and up here turns out to be 1.4 times higher than d. so i'm 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. let's 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 what's 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 don't fall together. you know why? because they didn't 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 didn't have to go very far at all before reaches tv, maybe accelerate it for about a centimeter, then it's tv all the way down. so you know what i'm saying? but these things will accelerate all the way to the floor. but if i put these in a more viscous medium, then it won'accelerate 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 it's got a weight-area 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 i'm gonna do-- [laughter] --i'm 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 we--he had this little thing made out. isn't that kinda neat, see? oh, yeah. [laughter] here's what we're gonna do. this is ted's idea, by the way. so what we're gonna do, i'm gonna put this up here. oh, no, no. it's my idea to screw it up, okay? [laughter] so i'll put the bottom-- this one here.

oh, what we've done is we've 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 it's at 1.4, same thing we've got with the cops. so let's try it now. right there. there we go. oh. that's why we get this-- oops, more water. oh. oh, we've got some more water. it's good--on that, yeah? [laughter] okay, here we go, gang. the little one here. [laughter] big one here. and i'm gonna flip this off to the side and see if you don't see them both fall at the same--

yehe yehey. huh? isn't 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. ain't 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. that's 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 can't keep up. the little things have more resistance compared to their strength. the effects of scaling. yehey. [music]

you are bonkers 'cause iron doesn't float. people make boats out of wood. well, here's this clay, and it has the same weight. watch this. oh, yuck. [laughter] yucko. yeah, we got it now, gang. isn't that nice? now it's being held up by what? your fingers. my fingers. you get the idea. ncentration of force is pressure. so let's talk about that, gang. pressure, definition. screwed up. i don't 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 book's easy. how about something like this? there's 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? it's 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 that's true by seeing if it will balance. and it does. so it's somewhere along there-- where along there?

i can hang it by another point and find out that it's-- now, troy, the center of gravity of this board is within the board. that blows everything, gang. i don't know what to do. yeah, the board's too fat. look at the globe here in the summertime, amsterdam is way up here, okay? now, let's suppose we have an imaginary line right in here about where darkness is, okay? everything to this side here is dark,

'cause let's suppose the sun is coming in this way, okay? sunlight is coming in. well, let's 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, they're in the sunlight. the sun come right here. most--i've got this wrong. i've got this wrong, gang. i've 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-- ay, it's g 24 times as much area to feed itsf.

but what's wrong with that, gang? twenty-four 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, w, i mixed up, gang. i'm getting mixed up. it is four times as much total area, because 24 is four times six. four tes six, that's why i screwed up. what i'm gonna do? what i'm gonna do? how do we start that? thanks for bailing me out again, lee. what are we talking about-- i'm self-conscious when this camera is on me. thcell 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 at you -how about me, yeah? [laughter] the living cell gets bigger and bigger, right?

let's suppose the living cell gets double the size. slig, uh-huh-- what do we got here, gang? [laughter] what do we got here? trouble. i've got a tablecloth. i've got a tablecloth with no lip, okay? - no. - watch this. those dishes are essentially at rest, aren't they? here's something for you to do this weekend when you finally get invited to your friend's 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 don't wanna try this at your own house, not with your own dishes, okay? you might mess--but you try them at your friend's house. how about this, gang? what's gonna happen if i pull this thing very, very quickly, huh? what's gonna happen? -- let's try it. a one, a two, a three. and there you see newton's law flawlessly executed. at distinconetween-- that dtinction between weht and mass,

i can kind of show you that kind of neatly with this device. what i'm gonna do is take this heavy ball-- heavy ball or massive ball? - both. - yes. both, yeah. see, i'm gonna take this ball. it's got a lot of mass, also has a lot of weight, okay? and what i'm gonna do, i'm gonna take one of these strings in the bottom. you see i'll try different trials here. and i'm gonna pull, pull, pull. i'm 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 slowl gang, which string gon break, top or btom? - top. - top. top one? how many say the top? let's try it.

[laughter] maybe newton's 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 start the tape... t with aangle li that, doesn't it trave a greater distance than the one that's 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, i'll step off like this. i'll step off like that. i'll hit at the same time in all places. over here, i'll be going faster, because i have a bigger speed like this. and that arrow is gonna be bigger than this and this. i'd be faster, but i've gone a further distance. - right. - okay. and later on we'll talk about a neat, neat concept that'll tell you that down here, the--wait a minute, i will not be going faster. erase the tape.

lionel, that's wrong. it turns i'll have the same speed here, here and here. no, i won't either. no, i won't either. now, lionel, the tape's 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, don't feel bad. i'm with you, all right? with this clip, i'm gonna fasten the point to here. now, i'm 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 don't see that, then you got to do your exams and study and da, da, da, da, okay? so let's try it now. [laughter] i've seen it.

scouts honor. scouts honor. never go back on a scout's honor. [laughter] oh, boy. [laughter] it's almost as if there's a spark there, isn't 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. can you put it on the other side? this should--it should be less probable, though, but-- you see it's got to leak from one to the other. i wonder if it's because i didn't discharge it to begin with. let me try something. --continuing to charge. isn't that in a way-- yeah, it does. it turns out it does, yeah.

but i could--you crank it counter clockwise. okay, watch this now. it shouldn't do. [laughter] that blows me out. that blows me out. this has never happened before. i've never noticed-- and if the leak's ofthat poi, then it shouldrift over here without having that snap, ap snap, and it's not happening. try to--when you put the two points on it, you turn it the other the way. oh, well, i didn't 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 guys should all be saying, "oh, gee--so we could--

eah, wcan test to see whether things are *true. "if bring a positive--i bring a positive object nearby, "shouldn't the positive object attract the negatives and pull the negatives from there? mm-hmm. and shouldn't 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. let's 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? it's getting me and more diversion. and it should collapse when i bring this over. it should. what do you mean it should? it's doing what should. my explanation is just off, right? [lter]

look at that. i've got nothingo-- i'm supposed to be teaching you guys electrostatics. i've got nothing to say. in fact, pbably everythi i say is just all canned crap. [laughter] because, honey, it's just not doing. look at that. i' got nothing to say. i could talk about coulomb's law a litt bit, but i don't believe in it anymore. [laughter] let's continue as if everything were goi smooth. it's called make believe. i thought science was all about making discoveries, expemental and-- we could continue with this, couldn't we? we could continue and maybe find something fundameal, but it's not part of my act. [laughter] well, okay, let's move on, gang. i don't know someone's gonna give me an explanation of what's happening here.

and i'm gonna be very pressed. who is going to be the one? in fact, that could be like a term project. what went wrong tonight? who's goa say, "hewitt, nothing went wrong at all. "what happened was, da, da, da, da, da, da, da. "what went wrong was your failure "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]