So, we came to doing the Sperry Gyroscope Company in 1940 W.W.II was looming. Sperry not only had the gyroscope at their northern bombsight, it was very critical from a national defense policy, it was a critical area and yet they did not feel that in any way it would be putting that operation into jeopardy to have me talk something about the technology. At any rate, the very essence of the Sperry Gyroscope Company was the gyroscope. And the gyroscope does what it does -as pure "precession" which is employed.

The said, just to show you how impossible your task is with a double spread, we have to have a primer for the Naval Academy midshipmen because the navy uses so many gyroscopes for so many controls, that the naval officer has to have some important insights into what he is dealing with. Therefore, we have this primer, and it takes 50 pages to tell the Naval Academy midshipmen about "precession" in an important way, and it is entirely quantum mechanics. So they said "Your task is impossible."

Now, I had only 30 days to work on this story, and I did come out with the explanation of the "precession" and the gyroscope, which I brought to one's own senses, and did clarify and the scientists of the Sperry Company said they really were astonished, but they agreed that it was not just a sort of happy analogy I was using, it was absolutely the direct explanation. They had not realized that it could be experienced in terms of the senses, because it seemed to be a very perverse matter, precession seamed to be a very perverse thing, like a kid saying "Why doesn't the top fall over?"

Now there are several matters that are going on. There are "precession" where we are dealing in acceleration. And there are two kinds of acceleration which are recognized by the physicists. They are what we call linear and angular. Linear obviously like that, and angular, think of swinging a weight around your head, like the hammer thrower, it is angular acceleration while you are having some restraint on it and while you are making it work in a circle. When you let go of it, then it goes linear. Radial. Radial versus circumferential.

The "precessional" is that, and we're going to try to get some sense of understanding why it is, because I am sure for most people, then, the feeling that gravity is 180 degrees, for instance the earth ought to fall into the sun. And why does the effect of the sun on the earth make it go around it at 90 degrees instead of falling in. This is one of the reasons why it seems perverse because everybody, the child, really thinks about the gravity pulling this way it's a 180 degree affair, and human beings get to be very linear this way, and they want to explain things very linearly. They're looking this direction.

Now, I'm going to go into my explanation. I'm going to think about an athlete we call a hammer thrower. He has a heavy weight metal ball, connected to a rod and two triangular handles professional hammer throwing. And he it's lying on the ground and he gets it into acceleration, and as he gets into acceleration, it gets out horizontally. And here we get into something quite important, because he can actually build energy momentum into the system as he gets to accelerating this weight. He gets going faster and faster, really using his muscles to get enormous acceleration. In other words, you can accumulate energy in this angular acceleration. So, when he does let go of it, it goes off on a line, with that angular acceleration, how far he throws it, how much energy he really got built into the system.

I'm going to have a special apparatus for our Great Olympic Hammer Thrower. I'm going to have a wide belt made for him very powerful belt, and it has many hooks on it powerful hooks. And we get him to start the acceleration. He gets one of these balls accelerating and, we get him to hook it on to his belt. Then we give him another one, and he gets that going too, along with it, and that would probably be in the opposite direction just balancing the weights very spontaneously, and he gets that hooked onto his belt too. Now he's built up a lot of motion and he can't really stop very much, so we hand him another one, and another, and one by one he gets them accelerated and hooks then onto his belt. So finally he has a whole grass skirt horizontally out here of all these balls, and there is so much momentum built into it, that he cannot really stop himself and he would be in a lot of trouble. So, we've anticipated it by, the floor that he was on we had already made a turntable, a very nice turntable, a ball bearing turntable, but we had had it locked so he could shove off and get his acceleration. But now we release the table so that it will spin alright for him, and we also then, to make him very comfortable, we bring down a ball bearing pad on his head from an arm from above, and so he is between the floor and the pad and he is moving around very easily since he has built all that momentum so he's spinning around here. The balls are getting to be so many, they are touching one another.

And, we now then, I'm going to leave him spinning for a minute. We're going to another man that is really not in the Olympic game. He has a mouthful of plastic peas, and he's got an aluminum tube a pea shooter. And he's blowing peas out of the end of the tube. And we could use other things. A machine gun would hurt you if you put your finger in the way. We could use a hose of water, but you can't see the individual molecules. A pea shooter is very convenient because you can see the individual peas coming out, and if he blows good and hard they go out fairly far. So you find that with the peas coming out you can come over and put your finger in the trajectory of the peas, and if you put your finger in kind of from the side like that you can make it deflect over there, can't you? Or put it a little bit under it and make it pop up a little. So you can change it angularly. This is our friend "angular valving." So we can change the trajectory.

Now, the fact is, that no matter how hard he blows, it only goes a little way before gravity pulls it to the earth. And so the gravity, blowing, if you don't put your finger there to deflect, and there is no wind as he blows it the pea operates in a plane, and the plane is perpendicular to the earth, as gravity pulls it so you would really describe this as a curve on a plane. So what happens when you put your finger there to move it on one side of the trajectory of the peas, you simply make a change like that and gravity still takes over, and what you really do is push the plane in which the pea is operating you push it a little this way. All right? Do you feel that? Then, if I remove my finger, the pea doesn't act as though it were an elastic band and try to go back to where it had been at all. It simply, it's changed its angle and gravity has also changed angle you've got two forces operating on the pea well three forces, the original acceleration, then my deflection, and gravitation's deflection. There are two angular deflections operating on it. The point is that it does not then have memory and try to go back to what it was doing before. You can understand that very clearly. The peas, simply, if I push my finger in here then the next pea will then go over here, then each pea has, however, a plane in which it moves. If we put a permanent finger here, into the trajectory, and left it there, all the peas would follow the same plane. You didn't push it any further. The plane could be reoriented, but the point is that the minute you stop pushing it it holds that plane. It does not try to come back to where it was before. Now, we've learned individual peas can be deflected. We can push one a little further than another, but the individual and once you have given it its new angle it is going to keep right on and now it is only being affected by the gravity. Gravity is the one that is altering it, the only one.

Now that we've learned what happens with an individual pellet, I am going to come back to, I recognize then this hammer thrower going around here, these are individual pellets that he has out there. They are individual energy units, and they are very much heavier than the peas, but they follow the same laws exactly. If you had cannon balls coming out and you had some kind of a steel finger you could put in the way, you could make the same deflection.

Now, I'm going to point out that the ball bearing turntable we had underneath the hammer thrower and the ball bearing pad on his head each one of them were mounted on vertical arms, a vertical arm going this way and another vertical arm going that way. And they were mounted from an annular ring a great big annular ring, and the annular ring would go 90 degrees around on it from this pivotal point, and we've got another set of hinges of trunnions. We built what we call and that's mounted in another ring gimbals. If you've seen gimbals for a gyroscope, and it has now all x,y, z axes of rotatibility. So this man is spinning and he is in gimbals.

Now I'm going to have him spinning out here in front of me. I'll have him spinning over here, and I'm going to come over here, and as those individual pellets go by hammers if I put my finger down, and maybe I'll put something, a guard or something on it, so it won't hurt too much put my finger down and touch one of those balls I'm going to deflect it agree? So I keep my finger there, and once I've deflected it, it hasn't any memory to want to come back, so as the ball is going around this way, and I touch it, then it goes down like that. But it had another restraint, which was the rod pulling it through, just as the pea had gravity pulling it, its own acceleration has been where gravity was no longer affecting it you can do that but the point is that the rod was really tantamount to the gravity that pulled on the pea, so after I touched it the rod is still holding onto it, so this pellet went by me here, and I touched it, and it went down like that. But it's on the rod so it's going to go round in a circle. So I keep my finger there then touching each one of these pellets as they go by, and each of them peels off. I've got a nice mathematical control for my finger so I'll just give each one of them exactly the same touching, and each one of them peels off like that one after the other, very much like airplanes coming along in flight, and they suddenly peel off one after another. They get into, then a new plane. The wheel which had been revolving horizontally here, you can see the man's in front of me here, and I've just touched it at this point, so each one of those pellets goes slanting down like that, from where I've touched it, it slants like that but then it stays in and goes around and comes up on the other side, so for the moment there is really a terrific bending of this thing, because it is at a very severe angle as you touch it. And I keep my finger there until the whole thing has gone by and everything has changed. It means then that the plane that I have been dealing in I wish I had a little larger disk. Could you let me have your book. So I touched the pellet here, one by one, and they slant like that because I did that. Could you see that? My deflection was this way as it went by, so this does this, but it was restrained then, so the whole disc does this. Which means then that the axle of that wheel, also then has to stay perpendicular because we had him with a very wide belt and he just normally has to do this, so the whole gimbals permitted it there were hinges on the horizontal annular ring, so the whole thing was able just to hinge that way. So when I touch it here, the whole disc changes like that, where the axle just goes over do you see that? It feels absolutely normal to you what I showed you doesn't it? Nothing wrong with it. That's exactly what these wheels do.