The tides are influenced by the moon. The tides are influenced by the sun. Which plays the greater role in raising tides, the moon or the sun . What is it . The moon. I got a different question for you. Theres a force of gravitation between the oceans of the earth, the oceans of the earth and the moon. There is also a force of gravitation between the oceans of the earth and the mass of the sun, so both are pulling. Which do you suppose pulls harder on the oceans of the earth, the moon or the sun . How many say the moon . Stand up. How many say the sun . How did you guys know its the sun . How do you know . Where did you find it . How could you not read the chapter and be astonished by that . I always used to think that the moon pulled harder on the oceans because its closer, and the suns so far away that the pull is a lot less. Thats what i used to think, and then i get into my physics and boom, sometimes in physics you find things that are kind of like counterintuitive, dont they kind of say, hey, wait a minute, whats this, huh . And whats going on . It turns out that sun is far away, but honey, it is big. Let me put it this way. You know the suns hot and when you step from the shade into the sunlight, you can feel the heat of that sun, right . And you might say, wow, it feels i can feel the hotness because the sun has got such a high temperature, but you know what gang . I can bring you to welding shops wherein the welding, the torches of some of those flames are hotter than the surface of the sun, hotter, and you walk by that welding shop and you dont, whoa, go like that, but you step from the shade into the sunshine and whoa, you feel it. Its not that the sun has a high temperature. You know why that sun is so hot . Because its big. I mean, big, big, very, very big, but its far, but its bigger than it is far and it pulls on the earths oceans more than the moon. So how come we get then the tides by the moon . And the person to figure that out was named isaac, guess what the last name is gang . You know, how many people would not be knowing . Isaac newton is the one that figured that out. Lets suppose we have a ball of putty or a ball of taffy or a ball of jello, something thats really pliable, something that you can whang around a lot, okay . And lets suppose i pull it across the room, and i pull it everywhere with just the same amount of force. What it would do is itll race across the room and when it got here if you took a snapshot of it, it would still be in a ball shape, okay . Lets suppose instead that i pulled on that jello a lot stronger here on this part and soso in the middle and over here a little bit weak quite a bit weaker. Ah, now i have a difference in pulls across the jello. That jello, gang, is gonna race across the room. When it gets over here and you take a snapshot of it as it goes by, would it have that shape . No it wouldnt have that shape because this side here is accelerating more than this side. Its a pliable stuff now, so this side here would, maybe, get out to here. This side here is not being pulled so far, that would lag behind over here and so what would happen to the shape of the jello, gang . Itll be kinda like this. Itd be kinda stretched out, wouldnt it . And guess what behaves the same way . It begins with o and ends with cean, try it. The ocean of the earth. Because it turns out, this is our earth, heres the moon over here. The moons pulling this side harder than its pulling this side. Why . The answer is easy. Check your neighbor to be sure were all there. Why is this side being pulled harder than this side . How many say because this sides closer. Its closer. When youre closer the gravity is stronger, hey, no big deal, huh . And thats right. So this side is being pulled out into a shape and this being left behind. Now is the earth really moving towards the moon . We on earth think, no, no, no, no. The moon is moving toward the earth. Theres a force on the earth, i mean, theres a Gravitational Force between the earth and the moon that pulls the moon this way, right . Why dont the moon crash . Because its moving like that. So as its being pulled instead of coming over here, its moving like this. It doesnt get to here, it gets to here. Its being pulled like that, instead of getting here, it gets to here. And so it gets pulled around and around and around in a circle, but guess what the direction of the acceleration is as its going around and around and around the circle . Its toward the center of the earth, see . So we think of the moon as going around and around and around us like i take a rock in the end of a string and i go whirl it around, around, around. We talked about the idea that the force along the string is acting toward me, right . The rock is really accelerating toward me. If it werent it would go somewhere else, but it keeps pointing toward me all that time, huh . I mean, its just huh, huh. Well, thats whats happening here too. The moon is being but if you lived on the moon, how about the moontypes . What would they see . Hey, no, no, nothing, the moon is center of the universe, the earth going around us. Whos going around who . Were both going around each other. Hey, you guys think the earth is just like this and the whole universe is going around you. Come on, okay. It turns out the earth and the moon going around each other, a Common Center of gravity. That Common Center of gravity is still inside the earth. Nevertheless, you can think of the earth as accelerating around the moon and this part closer accelerates more than this part and gets stretched right out and then the solid earth underneath like this rotating every day, huh, every 24 hours. So what do you do, you rotate right into a high bulge of water. Then we rotate into a low bulge of water and then to a high bulge again and then low and high and low and as this sort of turns, see, as it turns lets suppose the moons over here, huh, pulling, and as all the time would bulge out like this. Hey, im simplifying, gang. Im pretending that this earth mass isnt here. That makes variations that are very important. Were really simplifying, and consider the whole world to have no land masses that are going to get in the way, just the overall idea of tides, a bulge on this side, a bulge on this side and kind of shallow in here. So a person right here says, oh, wow, moving back here, the tide is high. Maybe its about a meter higher than usual over here. Well, the tide just went out. The tide got low, okay . And back here, the tide got high again, low, high, low, high, low, high. So how many high tides do have every 24 hours . Beginning with a t, two, im sorry. How many low tides do we have every 24 hours . It turns out every 23 hours, you know why . Because the moon just dont stay like that. The moon is kind of turning as its happening to so we could say, roughly speaking two tides a day, two high tides and two low tides. Thats kind of easy to see, isnt it . Stretch right on. If youre walking along the street and someone grabs your shirt and pulls it and they grab this part and pull it and this part and pull it, pull every part of your shirt the same, youll move over but your shirt wont get ripped. But you walk along the street and someone only pulls this part and they dont pull the other part, it might rip your shirt because one parts being pulled harder than the other and when you get a difference in pulls, then youre going to get a stretching effect and thats why we get the tides. We get a difference in pulls of the moon. Do we get a difference in pulls of the sun . Answer begin with a y, end with a p. Try it. Guess then, all right, the middle is a u, okay, yup. You do. You get tides from the sun as well, okay . But the suns so far away that it pulls just about the same on this side as on this side. Very, very far away that difference is not so much. So the sun is pulling like mad, 180 times harder than the moon but on nearing this far side, not so much different. Up close, yeah. You know what happen to that moon if that moon gets closer and closer to us. By the way, weguess what has two bulges as well, it begins with an m and ends with oon, try it. The moon. The moon gets two bulges too, okay . But the moon, of course, asthe bulges stay fixed because it rotates just as often as it revolves. We talked about that last time. So on the moon, you dont see it going up and down, up and down every six hours. It just stays up. Its like a football shape, okay . You know what happens when the moon gets closer and closer . The tidal forces get bigger, smaller or stay the same . Bigger. And, you know, what happens when the moon gets too close . They get ripped apart, ripped to shreds and all those shreds will just orbit around and spread out like a great big ring. Do you know there are planets where thats already happened . One begins with s, ends with turn. Do you know what it is gang . Saturn, thats right and the other one is uranus, neptune, okay. Rings, moons that have gotten too close and just simply got ripped apart, they are whole lot of boulders and theyre just all spinning around. Thats what they are. Tidal forces can be enormous when you are very, very close to something because the difference in pull between near and far might be greater than the force with which everything is held together with. Makes sense . So tidal forces dont occur too much for long, long distances but for short distances where the difference in pulls is a lot, the tidal forces can be enormous. We dont get the same depth of tide every day. Some days, the tide is higher and lower than others and the reason for that is because both the moon and the sun are pulling at the same time. You see, if i have the moon pulling here and i have the sun out here pulling in the same direction, thats going to make these bulges even more. The sun contributes about 1 4 as much influence as the moon. I mean, its still as big, okay . So when theyre lined up, you get extra high, high tides and extra low, low tides. And it turns out that if the sun is on this side or this side, you get the same effect. Its just if theyre lined up. Now when the sun is on this side, what do we call that condition in a month gang when both the moon and the sun are on the same side in between the earth or when the moon is between the earth and the sun . Do you know what we call that . We call it a new moon because at nighttime over here, these people here dont see any moon in the sky. You know, the moon is not out of every night, gang. Sometimes the moon is out in the daytime, okay . And if its exactly in front of the sun what do we call that . Not an eclair, what do we call that gang . An eclipse, okay, and notice a shadow coming right down here, its basking that shadow, okay . But usually its not lined up exactly, and so we call it a new moon. You look up, you cant see it because youre looking at the dark side, see, and then with a night sky. But how about the other case when the sun is on the other side and heres the earth in here and then we get the moon over here. What kind of moon do we see gang . Full moon, thats right. Because whats happening now, heres the dark side of the moon, heres the dark side of the earth. People up here look up and they see the whole moon full, you know. Its like the globe right here. If i play flashlight tag with you guys and i put the globe up here and when i put all the lights in the room out, black and everything, okay, and i get in different parts of the room and shine my flash light on the globe. Can you look at the globe and tell where the flashlight is . How about of the whole bottom of the globe will lit up in the top are dark, dark room, where will the flashlight be . How many say, oh, probably up there somewhere. Who . Stand up. Where will the flashlight be gang . Down underneath, yeah, yeah. And lets suppose you look at the globe and its all lit up, where is the flashlight . Maybe in back of you or in front of you but along a line where you are, yeah. And if you see like a quarter of it lit up over here, just a quarter lit up, wouldnt that be back here, maybe . This part be lit up and you guys could see this part lit up in here. So how the moon looks depends, of course, where the sun is, you know that. Its all the same. But when you have a full moon, how about the tides, extra high . The answer begin with a y. You got a friend and your friend wants to go clam digging with you. You guys know what clam digging is . You ever eat clams before . You know where the clams come from . The tidal flats, the mud, you gotta go up there and you gotta dig em. You gotta dig with a pitchfork. You dig em up and you do that at low tide, and when the tides really low, honey, you can go way up and get more clams. I used to do that a lot, okay, clam digging. Lets suppose youre going to go clam digging and you wanna go at the right time in a month and some guys says, hey, i know a good time to dig some clams. Saturday night is supposed to be a full moon. Lets go saturday. Well go dig clams at the time of the full moon. You are not too sure about that, so you consult with your friends who are knowledgeable about the wonders of the universe and those friends are sitting right beside you now, and you say to your friend, gee whiz, would that be a good time to go digging or not a good time to go digging . Check. What would be the answer, gang . How many say, yeah, i think thats the time of the month to dig your clams, honey. Thats the time im gonna go. Show hands. 1, 2, 3, okay. How many say, no, i think id go to the time honey when its got the least fullness. Ill go at the time of the new moon. Hey, even steven seem saying, no, im gonna go when its a half moon. Or, i dont know im not too good thinking about such things. Im here to take notes, gang. You tell me, ill write it down, teach and ill memorize it and im just looking for a c, anyway. At the time of the full moon, hows the high tide going to be . Extra high . Are you gonna go digging clams at the high tide . Are you gonna wait till low tide comes . You wait six hours later and you go, right . Now should you go at the time of a full moon . How many say, yeah, thats the best time because you can get more clams because the water go away, way out and you get a real, real, low, low tide. Show hands, only two people on this side of the room. I got something to invite you all to do saturday night when you take your bath. When you take your bath, i want you to get in the tub and fill it up and i want you to start sloshing the water back and forth. And when you slosh the water out in front of you and when it gets extra, extra high, thats the time of the full moon. Turn around quick and look behind you and guess what youre going to find . Guess what youre going to find, extra what . No, not high, extra what . Extra low and thats time of the full moon, the extra high tide is going to be matched by an extra what . Conservation of water, theres only so much water to slosh around, see that . So the people back here are wonderful. They can kind of see that. If its extra high one place, honey, it got to be extra low somewhere where the water come from. So yes, you go dig in your clams at the time of a full moon right on because you have extra low, low tides. How many say, oh, maybe the tides are only confined to the water. It certainly couldnt be confined to the solid earth itself because its solid and rigid, right . Is the earth solid and rigid . About like an orange, whats underneath the surface, whats underneath the skin, huh . Youve been over the big island lately . Okay. It turns out as all molten and that molten is that molten part of the earth. Are parts of that molten part closer to the sun and the moon than other parts . Okay. So whats that gonna do to it . Stretch it out and you know what, gang . We have earth tides, earth tides about a quarter of a meter puckered back and forth, back and forth about every six hours just like the ocean tides, tides in the earth. When you suppose the highest probability is of getting a earthquake or a volcanic eruption, full moon or some other time . Beginning with f, full moon, why . Its extra stretched. San francisco earthquake, 1906, very close to the new moon and theyre all lined up, extra stretched. You also get tides in the atmosphere, the atmosphere of the world, okay. Its very, very low mass, theyre not big, but there they are, and at the top of the atmosphere we have all these ions. Ions are charged particles made by the cosmic rays coming in and splattering the air atoms and what we get is we get a big flux of a change, a change in the distribution of those ions with the position of the moon and the sun. And when you get a full moon or a new moon, you get the deepest, you get the deepest atmosphere and that gives rise to what is called these changes magnetic tides and these magnetic tides at the top of the earth regulate the amount of cosmic rays that come down and hit us. Did you guys know cosmic rays are coming through the ceiling right now and going through you . And if they go through without making a hit, who cares . But sometimes they make a hit, good or bad . It depends who was hit, and if its hitting you, its not good, okay. But hitting maybe some you dont like or these things going through us all the time, and theres a little blanket up there that regulates how much come through and guess when the greatest change from deep to shallow is . Guess what time of the month are the magnetic tides up there, when the moon is what . Begins with a f. Full moon. Have you noticed that your friends are sometimes a little more weird at the time of a full moon . It might have to do with physics. Lee. Would it be the same thing, theyre just about as strong as the new moon . Yeah, oh, new moon or full moon. When i say full moon, youre right. New moon would have the same effect, thats right. So the time of a new or a full moon, twice a month. Yeah. Do you guys be knowing what a blue moon is . This is not physics, a blue moon. I found out just two years ago what a blue moon is, once in a blue moon. How many people know what a blue moon is . One, but i tell you if i told you, i would rob you of years later finding out what a blue moon is. You say, hey, son of a gun, thats what a blue moon is . How about that . Hey, man thats pretty ill never forget that. But if i tell you in class, you forget it, right . See if you can find out from lee or someone else. Hey, what do you mean by a blue moon honey . Whats a blue moon . Is it really blue . The answer begins with a n. All right, ends with an n and with the o. Try it. Yeah, okay guys. But see if you can find out what a blue moon is, not physics. Kind of interesting. Question . Yeah, whats a harvest moon . Check that out too. Heres your earth gang. We stand at the surface. Were pulled down with a force. Were pulled down with a force of gravity between our mass, the mass of the world, the distance between our belly button and the belly button of the world squared, quick boom, we get that force called our weight. Isnt that true . So, we weigh, we have a weight because of the force of gravity. Lets suppose we went down inside the earth and get right at the center in a hollow part. Make believe its hollow and right down here, how much would you weigh, a lot or a little . A little. The answer begins with check your neighbor. See if your neighbor yonder this. Answer begins with a what . Not x, not y but z, zip. Honey, you get no weight down there . You know why . See up here, youre pulled like this but youre pulled over here too. Youre pulled over here, pulled in all these directions, you know, and all these directions pull you as if they were all acting straight down, see . All of those have a result and its straight down but when youre down here, youre pulled to all this, youre pulled to all this, youre pulled here, youre pulled here. Whats the net force . All these things combine to be what . Not as straight, huh, combined to be a zero. So in the center, you got no weight at all. Did you get me . At the center of the world, you just bathroom scale you wouldnt, you wouldnt squash the springs. As every part is being pulled in all directions, all the forces cancel out. How much you get halfway down . How much you dig a hole . And down here you put a bathroom scale on it. Would you weigh more or less . How many say, im not sure. Im not sure of anything in this world but i think less. Show hands. Yeah, everyone except the front row, except one. Okay, all right. Its not right, you guys go in the back next time, okay . See the other guys got hands to look at, see . See this back row types, and see the hands go up and they join the chorus, see . And you guys dont have that privilege. Im just kidding. It turns out you would weigh less and why you weigh less . Well, you could say with the zero here and the weight up here, its got to be in between. Or you could say, no, wait a minute, its not the way to look at it. When youre right here, youre being pulled down by all these ground over here but youre being pulled up by all this over here. This is sort of like an unpulling being done, isnt that right . Because were attracted to every particle that makes up the earth. So these parts here up, here up, here up, just off the scale a little bit and it turns out you would weigh less but rather than draw a line like this and say we can have this cancel that. Let me just give you the results of something really, really neat. It turns out theres another way to analyze it and thats this. It turns out that youre halfway down right here. If you take this particular radius which is less than the radius of the world now and consider that ground and take the mass of that ground and the mass of you and this distance square, that will be your new weight and it turns out if your half way down, it would be half, half weight. And, you know, what about all this ground here, you can throw it all away because all of this stuff here doesnt pull on you at all, not a net pull. Whenever youre inside a shell of uniform composition, that shell wont pull on you. You can just throw it out and as you get the smaller and smaller amounts, you can see that weight keeps going down, down, down, down and finally when d gets zero, youre down at the zero because theres no mass left but its the mass outside in that shell and you can throw away. Lemme show you a little argument for that. Heres a shell of warm composition. I think you can see that in the center, any object in the center would have no gravity because its being pulled in all directions equally. Do we see that . But what i want to do is i want to convince you that it would cancel out no matter where you are and so what well do is well take a point thats about here where this distance here is twice this distance. Do you think it would still cancel out this side and this side . What well do is well consider a solid coneof material. Well call this m1. Well call that d1. Well call this m2 and 2d. Well, just d and 2d. Lets look at our equation, lets have the equation guide you are thinking again. A force over here would be our mass, say the mass of a point, okay, times m1 divided by d square. Thats this force. The force thats pulling over here, you might think its more because its more mass or you might think its weaker because its further away and guess what one does to the other, okay . When youre out here, itll be twice as much this way but twice as much this way, so how big would m2 be compared to m1 . Do you see its four . Its four, so m2 would be four times m1. That would be like four m1s times your mass mp divided by this distance here, 2d square, but when i take the twice the distance and i square it, what do i get, gang . Isnt that like 4d square . And what will the force do . And whats this . The same done thing i got here. So, you know what, the pull here, the pull here, equal. I just took a place that was easy because i get twice the distance here as here. But you put any distance you want, and thatll happen. Anywhere inside there, therell be no gravity. Therell be no field region, inside a shell like that, therell be gravityfree region. Therell be no gravitational field due to this mass. It would cancel out everywhere. So if you ever get to a big, big hollow planet, the people on the outside of that planet would walk around as if all the mass would concentrate at the center, but down inside there, you know what they do . They just float around, honey. The gravity would cancel out everywhere, very, very neat. So all were doing over here is when we take a shell, all this cancels out. No matter where you are, get right here all the all theto here will cancel, all theto here for that shell really, really kind of nice. Lets take a case that sort of has a different result all together where we get closer and closer to the center. Lets take the case of a collapsing star. Lets suppose youre standing on this planet, star or whatever and here you are and youve got a certain weight. Lets just call it 1, thats your weight. You know what that weight is, that weights the result of your mass, the mass of the whole star, divided by this distance square. Well, that distance is here to here, okay . If this is a very, very massive star, youre going to have more weight. If youre more massive, you have more weight. If the distance is greater, you have less. What were going to do is were going to pretend that the star collapses and were going to see what will happen to our weight at the surface. Lets suppose the star collapses to become half size. Well, youre still at the surface. It still has the same mass. If you take a loaf of bread and squeeze it up to its half size, it still has the same mass, its just more compact, yeah . Okay, so we still have the same mass, you have the same mass but their distance now is half as much as before. Well, that make you weigh more, less or stay the same . Well, we can kind of put the numbers in. Heres your mass, the mass of the star but now the distance is half the distance that we have over here but its squared, isnt it . And cannot write that like this . Cannot write that like this . And cannot write that like this . And isnt this what we had over here . So how much do we weigh at the surface there . Four times as much, you would weigh four times as much when you get closer. On the earth, you went half as close and you got you weighed a half as much burrowing inside. Thats because the ground is pulling the other way, but over here now it increases because youre getting closer and theres no other mass pulling you off, so it increases. If you understand that, you can answer this question. Lets suppose this star collapsed and you rolled on it and youre right here and it collapsed as to 1 10 the size, so its d 10 of the radius, 10 times closer. How much more youre going to weigh . Check your neighbor. Whats it going to be, gang . It turns out 100 times as much. You would weigh 100 times as much at the surface of that star and it would become harder and harder to throw things into orbit, harder and harder. Later on, were going to learn that the surface of the earth to throw something away from the grav to escape, to escape the locality of the earth and to keepto outrun gravity, you would have to throw something at 11. 2 kilometers per second. Thats called escape speed and were gonna learn that on the sun for something to be ejected off the sun, so it doesnt get suck back in again. So we can outrun the ever present sun gravity, you have to go at 620 kilometers per second. Thats the escape speed for the sun. What do you suppose happens to the escape speed as it gets closer and more and more compact from the surface, get harder and harder, you have this a little faster and faster, or slower and slower, what do you suppose . Common sense, well now, whats physics anyway, gang . Common sense, isnt it . Okay. And it turns out it would be youll have to throw it faster and faster and let me just give you a little fact. If our sun collapsed to a size less than 3 kilometers in radius and all the matter of the sun gets scrunched up to less than 3 kilometers, do you know how fast you would have to throw something from the surface of the sun to escape . 300,000 kilometers per second, thats the speed of light because from that particular configuration, escape speed would be the speed of light and if it shrunk down any more than that, forget it. You cant move anything at the speed in fact, light itself couldnt get out. You know, right now, you look at the sun as nice and bright, yeah . If i cut that small, ooh, i cant see it anymore because the light itself would be sucked right back into it, the enormous gravitational field at its surface. And so wed say, its just part of the black sky. Wed say, its a black hole in space and thats what a black hole is. Its a star that collapses and the gravitational pressure collapses and becomes and whereby it collapses to a point where the escape speed is the speed of light or more, black holes. It turns out, gang the astronomer types tell us that the sun will never become a black hole. Its simply not big enough and the gravitational pressure wouldnt do that. So black holes are made of larger stars, but nonetheless ive got an intriguing question for you. If our sun did turn into a black hole, what effect would there be on the orbital motion of planet earth . Do you suppose you could grasp physics enough to not remember it, but to understand it . Lets try, lets try. Over here, we went from a weight one to a weight four, to a weight 100, aint that right . Lets suppose over here when this star collapsed down to half size. Lets suppose we climbed the ladder. And at the top of the ladder, we put a bathroom scale and we weighed ourselves with a more highly packed dense star. What would you weigh up there when youre just as far from the center compared to here . What your neighbors say . How many say, same, same . Hey, thats right. You know why . Because your mass is the same, the massis the same and the distance is the same you had over here. So you wouldnt weigh more or less. Every part of your equation would be the same, these equations guide our thinking, gang. They tell us how to think, over here, lets suppose you had a ladder, get a longer ladder now. So youre just as far out from the center of this than you were to begin with . What would you write here compared to over here . The same, its one more step, gang. Lets suppose this thing collapses to a black hole and somehow a thought experiment, you can put a ladder here and you stand right there and youre like, oh my gosh, you black hole, ive read about those dudes. Hows your weight going to be . How many say, this time not the same. Show hands. How many say, no, i think the same. Show hands. Yeah, all right my people. Whats going to change . Not the gravity force, maybe the sunlight, you might get cold, okay . But this doesnt change. This doesnt change. The weight doesnt change. The only thing that changes is this mass gets crunched up, but theres nothing in the equation that talks about that and, you know, whats after the equation . A period. So whenever i ask anything about gravity, the only thing is to consider what are the masses involved . How far away are they and thats it. And if you want a numerical value, then you have to put in the g which will make this have the same unit as this side, but thats it, thats it. See what i mean . The equations guide youre thinking. So it turns out if the sun turns into black hole, everything would be okay. You know why the suns round . You know why the earths round . You know why the planets are round . Because if there are great, big cubes the corners could be pulled in by gravity, gravity pulls everything in until it gets round. The whole universe, it turns out the idea of gravity underlies our thinking about the universe. You guys hear about the Big Bang Theory . The idea that about 14 to 20 billion years ago the whole universe was in one point and exploded out, all flying out. Lets look at that in terms of the gravity bit here. Lets suppose, heres the big bang and all these pieces are flying. Now lets suppose that we knock the whole universe into four halves just to make the thinking easy. If we can understand the simple examples then maybe we can deal with complexities. Heres part of the universe here, heres part of the universe here, part of the universe here and all are flying apart. Theres nothing else that exist just this and there they go. Any force of attraction between these phases . How many say, yeah . It turns out this would be attracted to here, this would be attracted to here, be attracted to here and all these will act as if what . Itll all act right back down there and this would act back down there. Therefore, these things would be going against a Gravitational Force. If thats true and the universe exploded, does that mean as time goes by the universe will speed up or the universe would slow down . And it turns out the universe should slow down if this model is correct, and you know what . When the astronomer types look out in the heavens, they find out that the universe is slowing down. You know, how they know that . Because when you look at the things that are furthest ago, i mean, furthest away and the thing thats furthest away is longest to go. You guys hit to the idea that it takes 8 minutes for the sunlight to get from the sun, right . When you look at the sun, youre looking at 8 minutes ago, you know that . And the next near star alpha centauri, looking at it four years ago. So if youre looking at something way, way back there, youre looking at it way, way back in time too and they find out the things that are farthest away, longest to go, were going faster than things now. And that means, the universe is slowing down and furthermore we find everything is getting further, further away from us, its like a balloon expanding, expanding and everything is getting further away, slowing down, slowing down. Maybe what happens is it goes like this. And maybe it just keeps going forever and ever and ever, but maybe it might go. To a whole universe . Its calculated to be about 100 billion years. Its called the oscillating theory of the universe, every 100 billion years another cycle. Now take your diaries, take all the things that you like, take all your scrapbooks, okay . Put em in a nice lead, lead casket, gang and when it comes and goes like this, how much is going to be left . Nothing, it turns out, i dont think we can leave a record. Alleverything would beall the atoms, everything would be smashed right back down to elementary parts and fly right out the other side and the whole should bang go again. The whole dance, the whole story, and maybe be a little different next time, maybe not. And how do we know . We dont. And if there is, how many times this happen . We dont. We think about these ideas. Those are big ideas, gang. What is going on with the whole cosmos, and there are people that from day to day work on those kind of things and thats how they bring their lunch every day to work on. Those are the astrophysicists and the astronomers, really wild stuff. But when you start to think about these things that are far away like that and big, it kind of humbles you. Because lets make a graph about what this whole thing is. Here we are right here. Here is the big bang, im going to just draw a graph right on this space here. Heres the big bang, this is 50 billion years later and a hundred, okay . When is the time that human beings learned how to control fire in this whole cycle . Its about here. When that graph is about here, the human beings learned how to make fire. Where are human beings now . About here, okay . Heres where we used to be when we were in the caves and now were like this and we got this to go off in this one cycle. I got a question for you. What will it be like . What will we be like when we get to here . What will be important to us . How will we relate to each other and how will our perception in the scheme of things be like when we get to here. Ive got a little mental exercise for you. Take a piece of paper and write down an operational definition of god, okay . God means many things to many people. Write an operational definition. By operational means god is a being, a spirit, a consciousness who can do this, like who can read minds, okay, who can be in all places at one time, who can. Make your list, honey, that being is what i called god, okay . Write that up. Take your list. Put it in a drawer. Wait. I speculate the day will come when humanoids could look over that list and say, yes, we can do all of these things. We all can now. If thats true then what is going on . Think about that