Fig. 27. Vectors and Position in Maxwell.
Maxwell, Matter and Motion
Part 1 (Preface; Chapter I: Sections 1–12)
MCKEON:1 We now proceed to Clerk Maxwell, and in taking up his views I think it’s well to bear in mind the continuities which exist between Galileo, Newton, and Clerk Maxwell. In order to keep the desirable dialectic at a minimum, let me review them. You’ve had Galileo: he had reflexive principles, an operational method, and an entitative interpretation. Newton had a comprehensive principle, a logistic method, and an entitative interpretation. So the continuity thus far has been entirely on the side of interpretation. The changes of method and principle have had interesting shifts, but most of the words have continued. I’d like to proceed in chapter I cautiously and watch what it is that Clerk Maxwell says, bearing in mind that since his answer to most of these questions is that he is telling you what Newton said, we are, therefore, engaged in something.
Let’s begin with the Preface, which is only half a page.2 Mr. Henderson, from the Preface what would you guess Newton had done? As you read along, I hope your reading habits would be such that you’d begin to try to place what is going on. Frequently, you have to revise it; but he is giving us a method in this half-page, then. What is it?
HENDERSON: I’m not familiar with the Preface.
MCKEON: Miss Frankl, have you been exposed to the Preface at this point?
FRANKL: Well, I looked at it.
MCKEON: Your habit is good. It’s wise to skip introductions by scholars, but it’s well to read prefaces by the author.
HENDERSON: Yes, but in this case, they’ve printed the Preface so separated from the text by the Introduction that I didn’t even know there was a Preface there.
MCKEON: Anyone have any idea? . . . Miss Frankl?
FRANKL: I think he did it.
MCKEON: I know, but this is not autobiographical.
FRANKL: What is the question?
FRANKL: What did you say?
MCKEON: What is the message that Maxwell is trying to get across? He is obviously telling you that something happened between the end of the eighteenth century and modern physical science. Mr. Newton lived on the other side of this fence and published in the seventeenth century, though he lived into the eighteenth. What is he telling you? . . .
FRANKL: I think it had to do with his method, and his statement that he’s going to stick to a “strict dynamical reasoning” would imply that he’s going to be logistic.
MCKEON: When you speak of something like dynamic, dynamic is a word which, for the most part, has had quite a pejorative sense in all four methods that I’ve laid out. Yes?
STUDENT: I think he’s saying that in the eighteenth century they examined natural phenomena by looking mainly at the forces between one body and another, breaking down the different forces.
MCKEON: But he’s going to deal with forces. He’s a big man on force. He’s the hero of C. P. Snow.3 He practically invented entropy, according to the modern view of force that we have.
STUDENT: Well, he goes on to say that he’s only going to deal with the idea of force in the configuration of motion.
MCKEON: Did Newton deal with configuration? He wrote a System of the World, tome 3 of the Principia. . . . You know, this either comes immediately or it doesn’t.
STUDENT: Well, the difference between this and Newton would seem to be that the parts are determined by the system, whereas in Newton the world simply began and from the smaller parts arrived eventually at the system. Here he says that the “system is conceived as determined by the configuration and motion of that system.”
MCKEON: I know, but what’s the difference, then? How would you describe the difference?
STUDENT: It just hasn’t existed according to the word energy by which his force . . .
MCKEON: I think Newton knew about energy. It wasn’t his favorite word, but he could have taken care of the concept. . . . It’s a slight point, maybe, but this is a clear statement about selection. He’s saying that in the beginnings of modern science, what you tried to do was to deal with the principles and the way they fitted the variety of things. We are now going to move over to the selection where method is basic: we’re going to deal with the total configurations first. This is the second period, and the dates fit in perfectly. Likewise, if we were writing a similar preface today, we would have to say Clerk Maxwell was quite a hero for his time; but you can’t do this anymore, you can’t set it up. What do you suppose a modern writer would say physics was supposed to deal with?
STUDENT: The basic or common facts that deal with a particle?
MCKEON: And very frequently they won’t fit into a system. But you can, if you begin with the facts, make proper adjustments, write the equations, and get everything in the system of the world stated. However, as I said, I just wanted to indicate that Clerk Maxwell is operating according to the distinctions we’ve set up.
STUDENT: So that I can understand you: instead of doing it in terms of Newton’s system, he’s doing his parts in terms of forces versus particles?
MCKEON: Remember, when I taught this class,4 we hadn’t talked much about selection. Selection is the way in which you pick your terms or you pick what you are dealing with. And when you look at that as a succession of times, that is, when you deal with the selection which makes the discussion among systems possible, even though each system has its own selection, your emphasis may be upon the nature of things: this is metaphysics or principles. Then, after men have been talking about the nature of things for a certain length of time, they’ll decide nobody can agree about the nature of things and so will discuss what the criteria of interrelations are before we get down to things; you are then over in method or epistemology, depending on whether you’re describing it in terms of the processes or the philosophic distinctions. In philosophy, this is the period in which Kant decided that you couldn’t have a metaphysics first. You had to have a critical philosophy, you had to deal with the forms of thought; and when you got through with the forms of thought, then you could go back to metaphysics. Here Clerk Maxwell is saying the same kind of a thing with respect to physics. Finally, after you’ve discussed epistemology for about 150 years, people say, You can’t decide how people think; what you’ve got to examine is what they do or what they say. If you find you can be clear about what they do and what they say, then you can decide what they think, and maybe thereafter you can decide something about metaphysics. As a result, in the twentieth century it would be natural that metaphysics is at a third remove, epistemology is still fairly respectable, but what you should really do is semantics.
STUDENT: Does that hold over into the relation between semantics and facts, the relation between thought and methodology . . .
MCKEON: The third shift is from method to interpretation. When you interpret, what you deal with are either things that men have said or things that men have done, and those are called facts. Indeed, that is what fact means.
O.K., having gotten our little review in, we are now ready to read chapter I. What I would like to do is, in the same fashion, to talk about the first three pages and view them in any order. Tell me what goes on here in the numbered paragraphs one to six. Mr. Davis? . . . I have this impression that I’m awfully repetitious in what questions I ask, and yet they always come as a complete surprise when I ask them.
DAVIS: To do it all at once is difficult.
MCKEON: [L!] Well, do it step by step. Take chapter I, section 1. What is the nature of physical science?
DAVIS: It deals with events, or more particularly, the succession of them.
MCKEON: He agrees with that? Remember, don’t tell me what he is saying; tell me what it is that you learn here. . . . Or even whether he’s talking about principle, method, or interpretation.
DAVIS: He says that physical science concerns the order of changes in the arrangement of bodies.
MCKEON: That’s what he says in my book, too. But what does that mean, Mr. Davis.
DAVIS: What does what mean?
MCKEON: I said, that’s what it says in my book, too, and, therefore, it’s not relevant. What do you say about what it says in the book. . . . Well, look, it seems to me that this is a very simple question and answer. What he says is that we’re dealing with any regular succession of events. Physical science could apply to any event at all, but in a narrower sense it doesn’t apply to biology. Consequently, we get to the motions of body. In a stricter sense, the first part of physical science relates to the relative positions and motions of body. This is the entitative interpretation if ever I saw one. He is saying that whatever changes occur, they are reducible to the motions of bodies and positions. Isn’t that true?
DAVIS: That’s what he says.
MCKEON: No, that isn’t what he’s saying. This is what the interpretation is. He doesn’t say this is interpretation, he doesn’t indicate the reductive aspect, he doesn’t show the way in which any kind of phenomenon can be reduced to the basic one; but that’s all of physical science.
All right. On the basis of this—is Mr. Dawson here? Mr. Flanders?
FLANDERS: Yes.
MCKEON: What does he then go on to do?
FLANDERS: He has a second move.
MCKEON: Well, O.K. Let’s step up.
FLANDERS: Well, he plots a material system.
MCKEON: O.K., he defines it. How does he define a material system in section 2? . . . Does he say, The way in which we’ll find a material system is to go out, pile it up, and take a look at it? We’ll get all the matter together, and we’ll get it in a pile; that’s a system. Then we’ll describe the way it’s piled up, all the ways in which it acts?. . . .
FLANDERS: Well, he . . .
MCKEON: Does he say, The way in which we’ll define a physical system is, first, to find out whether it has a soul, and then if it does, we’ll get its body all measured and see how it fits in soul? . . . What does he say? I don’t want to make this too easy. What does he do? . . . Mr. Wilcox?
WILCOX: He speaks of the definition of a material system as what we determine.
MCKEON: All right. We mark off our system by giving a definition to it. What would this mean? What is he saying about it, getting a material system?
WILCOX: Well, we’re only studying what we say we’re studying.
MCKEON: Do you mean that if I say we’re going to spend the next year studying my watch, I’d have a material system and that’s all there is? I’ll be studying only it and nothing will distract my attention?
WILCOX: Could you rephrase the question?
MCKEON: What?
WILCOX: Could you rephrase the question?
MCKEON: I want to know how you define a material system. . . . He says, “In all scientific procedure we begin by marking out a certain region or subject as the field of our investigations” [2]. How would we mark it out?
WILCOX: I still think it’s arbitrary, what he’s done.
MCKEON: O.K. What’s wrong with saying, For the next year I will get a hundred thousand dollars from the Ford Foundation to study my watch. I want to, the Ford Foundation likes me, I’ve got influence. [L!] Have I defined my field of study?
WILCOX: Yes.
MCKEON: No, I haven’t; absolutely not. I mean, if you think that I was anywhere near what Clerk Maxwell is saying . . . Yes?
STUDENT: I think that we’re focusing on what would be at the basis of the atomic particle construction. Maxwell is saying that a body would more or less be part of what we’re proving.
STUDENT: It’s not a body, it’s an entity.
MCKEON: It’s what?
STUDENT: It’s not a body; it’s an entity.
MCKEON: Oh, really?
STUDENT: Yes, a single material particle or a number of them.
MCKEON: Is the single material particle an entity? Yes?
STUDENT: I think it’s a beginning point, so that to talk about your system, whether it begins with a particle or it begins with a body or the interrelations of the body, it starts with a whole and then you talk about the particles. You’re not saying you’re going to study this single particle; rather, you’re going to begin by a discussion which will get larger once you start with a relationship based on single particles.
MCKEON: All right. How do we determine our system, a material system?
STUDENT: How do you determine it?
MCKEON: Yes. There are four different ways in which a material system can be determined. The description you’ve given could make up any one of the four.
STUDENT: Well, in this particular passage I don’t think he suggests what it’s going to be.
MCKEON: I would suggest that he does. . . . To begin with, which of our three aspects is he talking about? In the “Definition of a Material System,” is he talking of principle, method, or interpretation?
HENDERSON: Principle.
MCKEON: He starts with principle? Well, can you tell me about principle?
STUDENT: Interpretation.
MCKEON: We’ve got all three now! Let’s go around and find out why you think that he is talking about them in this fashion. Why do you, Mr. Henderson, think it’s principle?
HENDERSON: I think it’s principle because principle would involve the degree of complexity.
MCKEON: In terms of your interpretation of the Preface, do you think that this could be a principle in the nineteenth century? . . . If we were talking about the system in terms of principles, he would be dealing with the relations of forces acting between one body and another. That’s where you go by principles. Instead, he is going to talk about the material system—and the word is even in Mr. Henderson’s Preface—which is “conceived as determined by the configuration and motion of that system.” Why do you think it’s method?
STUDENT: Well, he starts out with systems of this.
MCKEON: Isn’t this the answer to it? This is a system. If this were interpretation, he would be answering the question, What are the entities that we’re talking about? If this were principles, he would be answering the question, What are the causes that hold the system together? But he is talking about the system itself. Remember, we said for method that there was a material and a formal side: the formal side would be the method of knowledge, and the material side would be the interrelations of sequence. That’s what he’s telling us; that’s why he wants a system, because he wants the interrelations first. If it is method—and let’s try this as a hypothesis—which of the four methods is it? Would it be dialectical?
STUDENT: No.
MCKEON: O.K. Why not? Well, never mind that. [L!] Could it be logistic?
STUDENT: Yes.
MCKEON: If it were logistic, what would we have to do?
STUDENT: Develop the system from a sequence.
MCKEON: No, no. What did Newton do?
STUDENT: He started out with parts, with quantity of motion.
MCKEON: Quantity of motion, the quantity of mass times the quantity of velocity. Does Maxwell tell you anything about the quantity of motion in this?
STUDENT: No.
MCKEON: So it’s probably not logistic. Is it problematic?
STUDENT: No.
MCKEON: Could it be operational? We’ve had an operational earlier. How did Galileo start?
STUDENT: He started with variables in an equation and applied them.
MCKEON: O.K. Which do you think this is?
STUDENT: I think it could be the problematic.
MCKEON: But I thought you said you didn’t think it could be problematic.
STUDENT: No, I said it could.
MCKEON: Oh, oh, I see. Well, all right. If it’s problematic, we’ve got to identify the substances, the accidents, and the problems. What are the problems that we’re going to deal with in our system?
STUDENT: The interrelationships.
MCKEON: That isn’t a problem.
STUDENT: What’s being included in the system.
MCKEON: No. A problem is something like this: if two balls strike each other and the one is heavier than the other, the heavier one causes the other to bounce off it. The problem is always a particular problem because it’s a particular method; and you’ll have many methods: that is, you’ll have one method for repercussion, one method for straight-line motion, one method for circular motion. Is he going to have a lot of ways of determining material systems?
STUDENT: No, he only has one way. In fact, he even uses it in his determination of distances in his physical science later on.
MCKEON: So, what’s the method?
STUDENT: It’s operational.
MCKEON: You’ll notice, he has used the word particle, which was also the term that Galileo used. When you get around to dealing with the representation of a particle, what is it?
STUDENT: It’s a dot.
MCKEON: He says so. All right. Let’s work on the hypothesis that this might be an entitative interpretation—that’s where your body comes from—and an operational method. Mr. Roth is not here, is he?
ROTH: Yes, I am.
MCKEON: Tell me about section 3, “Definition of Internal and External,” and section 4, “Definition of Configuration.” Even take section 5, “Diagrams”; we ought to get a little speed up now that we’re on the tracks. Why does he want internal and external? Or, how does he define them?
ROTH: He wants to know what we’ll consider once we mark off an area of a material system as being inside it and outside it . . . .
MCKEON: Let me indicate what I’m talking about. Once you get started on something, there are a whole series of ways in which you can identify what you’re talking about. You can make enumerations of characteristics or you can proceed formally. In the operational method, since you begin with undefined variables, you will normally begin with a pair of undefined terms, and you will give them a definition in terms of what you have thus far defined. Internal and external would be a favorite pair because it’s either in or out. You notice, he is defining internal entirely in terms of the system. That is, if you are dealing with relations among the entities in your system, that’s internal; but these entities or the system as a whole may be related to other systems, that’s external. So that—and this is another mark of the operational method—we have really not identified any of our terms with specifics: we’ve kept them variables. But if this is the case, what is a configuration, Mr. Roth?
ROTH: Well, it’s all the relative . . .
MCKEON: It’s what?
ROTH: It’s the relative positions in the internal entities and forces.
MCKEON: No. Notice the way in which he puts it. You take your material system and you can consider it in various ways. Consider it simply with respect to relative positions and then you have a configuration. If you have knowledge of the configuration, then you know the position of any point in your system—it’s a point now, you notice; the body has disappeared—with respect to any other point at that moment. So that configuration specifies what we’re going to do with a material system. How are diagrams related to this?
ROTH: Diagrams would be a model of the configuration.
MCKEON: Do they resemble the material system?
ROTH: Well, it’s supposed to resemble it. He says it’s a plot of the system.
MCKEON: Did any of you notice the respect in which they resemble the diagram?
ROTH: He says in form.
MCKEON: In form, but in no other way. Well, let me ask, Are there diagrams of configurations? I’m asking this because my next question will be, Are there other kinds of diagrams? And then I want to ask, What’s the difference between them? . . . Mr. Davis?
DAVIS: My first impression would be that configurations are a diagram.
MCKEON: If you have a merely geometrical figure which gives you the position of a point relative to another, then you have a diagram of configuration. But then he says, “Besides diagrams of configuration we may have diagrams of velocity, stress, etc., which do not represent the form of the system, but by means of which its relative velocities or its internal forces may be studied” [3]. So, again, the operational method with its application to many things appears in the uses of the diagram.
Miss Marovski, will you tell me what a material particle is?
MAROVSKI: It depends on the system which it appears in, and if it’s a body so small that the distances between its parts . . .
MCKEON: Is he still within the system?
MAROVSKI: He says, “[F]or the purposes of our investigation” [3].
MCKEON: “For the purposes of our investigation"?
MAROVSKI: Well, I think that . . .
MCKEON: The particle may be exactly the same body in exactly the same system?
MAROVSKI: Well, there’s nothing that can be true apart from the system of distribution. It’s not a concrete definition.5
MCKEON: Well, if I had the sun in the system of the heavenly bodies, is that a material particle or not?
MAROVSKI: Yes.
MCKEON: It depends on the purpose of my investigation. If I had an atom, is that a particle or not? I mean an atom within a cloud chamber with one million other atoms and only a million.
MAROVSKI: It depends.
MCKEON: All right. What would be the purpose of the investigation that would determine whether it’s a particle or not?
STUDENT: Whether or not it’s a system of other atoms.
MCKEON: No. In terms of system I’ve deliberately taken two examples, the atom and the sun, in which they’d be in exactly the same system; but I could be investigating them for different purposes.
MAROVSKI: He says that if they rotate, then you have to consider them as being more than one particle.
MCKEON: When would I be able to represent the sun as a point, to use some information we’ve just had?
MAROVSKI: When the action’s between it and the other—when the action’s within . . .
MCKEON: I don’t think we have any action. Suppose I were making a star map. Could I represent the sun as a point?
MAROVSKI: Yes, that’s easy.
MCKEON: I know it’s easy. Suppose I were trying to make a planisphere, a small model of the revolving universe. Could I make the sun a point?
MAROVSKI: If you’re not going to let it rotate.
MCKEON: Suppose I’m just going to represent it on a piece of paper with respect to its rotations. It would look very much like a star map, but what would I need to have in addition? . . . Yes?
STUDENT: It would have different motions.
MCKEON: It would have to have a vector.
STUDENT: You’d want a diagram of a configuration in order to . . .
MCKEON: That’s right. Consequently, even if I made it very small, just a dot, I’d have to put a vector in to show the direction in which it is rotating; and it couldn’t rotate unless I could distinguish its left hand from its right hand. The same thing is true even of an atom, which for other purposes is indivisible. If I am taking my indivisible atom and rotating it, I’m putting in a vector, and a vector gives us subdivisions. This, then, is what a material particle is. It is not an atom, as one of you intimated before. It is any old thing you want, considered in a way for investigation which requires nothing more than the representation of it by a point. It can be as big as you like. Are we doing all right?
Is Mr. Knox here? Mr. Dean, tell me about section 7, “Relative Position of Two Material Particles.” What aspect does this add? . . .
DEAN: Well, the diagram includes two particles and their direction.
MCKEON: Say I have a diagram of two points, A and B, on the blackboard, and the relative position is such that B is to the right of A. Is that what you’re saying? Is that adequate so that you could perfectly identify it?
DEAN: Well, it would be both the direction and the . . .
MCKEON: What do you mean, “the direction"? All you need say here is “to the right of.”
STUDENT: You have to tell how far.
MCKEON: Four inches to the right. Is that what he’s saying?
STUDENT: It’s a diagram?
MCKEON: In order to get a vector in, what would I need in addition to what I have there?
STUDENT: You have a point and you need a direction.
MCKEON: You need the operation by which you draw the line and, in point of fact, along with this, even though I could identify it, I could either draw the line one way, from A to B, or draw the line the other way, from B to A. You have two different vectors. It’s essential to what he’s doing because by means of the vector, you don’t have to go into a lot of talk on this point. I mean, we’ll eventually find our way to start, but the vector gives you the operation by which you move from point A to B. The vector, therefore, is a quantity with a direction. This is of extreme importance when you’re dealing with objects rotating, which likewise have a vector.
But go on from there. We’ve done sections 7 and 8. Tell me about section 9, “System of Three Particles,” because we’re beginning to use our vectors—or, first, tell me when vectors are equal.
STUDENT: When they’re parallel to the same thing in terms of points.
MCKEON: Same parts?
STUDENT: Well, he said . . .
MCKEON: No. What I’m trying to get is, What is it that you would look for if you want equality of vectors?
STUDENT: Their magnitude and their direction, to find if they’re parallel.
MCKEON: Yes, the direction. And why don’t you bring in the box?
STUDENT: Because he set it up in terms of parallels of vectors of the same magnitude.
MCKEON: No. All you would need would be the same direction and the same amount. But the important thing . . .
STUDENT: What about the parallels?
MCKEON: . . . the important thing is that direction has come in. And this grows out of what Newton did. Remember, one of the reasons why he found it necessary to differentiate sharply the circular motion of centripetal force from straight-line motion was that in the mere alteration of direction from straight-line motion you have an acceleration. Consequently, with respect to the center of the earth, for this reason it either is at rest or moving in a straight line; it would manifest a force before making a circular motion. Therefore, in the vector you need to have both the amount of the force, velocity, or whatever it is that we are measuring—the operation—and the direction. The direction is just as important as putting more muscle into it.
Tell me about the “System of Three Particles.” I want to get through these rapidly because then we come to the important questions.
STUDENT: Well, if you know the relation of two of the points to the first, let us say, you also know the relation of the second to the third.
MCKEON: No. All this could have been done statically. In other words, A, B, and C could be looked at merely as the points (see fig. 27).6 Is that what he’s doing?
STUDENT: No, he’s using B to . . .
MCKEON: It is the operation, and the word is here again. In other words, what he’s interested in is how you get from A to C, and you get from A to C either directly or by way of B. And in that case, your component vectors would be different but your final vector would be the same. How do you add vectors?
STUDENT: Ah, you can . . .
MCKEON: Addition and subtraction you ought to be able to get into one sentence. What is it that he’s talking about?
STUDENT: By the operation of . . .
MCKEON: How you get from one place to another and, therefore, the order in which you add makes no difference, even though making the journey one way might be harder than another. How about the subtraction?
STUDENT: It’s the same circumstance.
MCKEON: Once more, the important thing is that what we are interested in is getting from one place to another. Therefore, the subtraction is not of lengths but, rather, of what you need to take away in order to get to another point if you started off from a given point in the wrong direction. And this would be taking away directions.
Well, this gets us to the place I wanted to come down on. I want to know about section 12, “Origin of Vectors.” Mr. Flanders? Mr. Kahners? And don’t begin by saying, “He says . . . “; tell me something about what he says.
KAHNERS: I think it’s important because it’s going to alter the direction of vectors between two points, depending on where you choose the center.
MCKEON: That’s true, a high moral sentiment. [L!] What else? . . . Let me start you. Whatever he’s doing, it is perfectly clear that he’s trying to say that if you want to find the position of any of a number of particles, it doesn’t matter where you start. What, therefore, is the mode of thought that he’s using?
KAHNERS: I was going to tell you about his method.
MCKEON: Well, we don’t know yet whether it’s a method or not. What is the mode of thought? It’s discrimination, isn’t it? I mean, in other words, it is relative to where you start going from. Since it is discrimination, what is it that he is worrying about here? In other words, which of our three aspects do we have? Or, tell me something else as a way up to it . . . . Does it matter where we start?
KAHNERS: Well, it matters, but you can start anywhere.
MCKEON: You can start any place, but in what sense does it matter?
KAHNERS: Well, wherever you start, it’s going to determine the relationships.
MCKEON: Oh, really? No, that’s what doesn’t matter: no matter where you start, the system will remain the same. Isn’t that what he says?
KAHNERS: Yes.
MCKEON: All right, in what sense does it matter?
KAHNERS: Well, if you could do it the right way, then certain inquiries and procedures will be more . . .
MCKEON: You’ll simplify inquiry if you pick one rather than another. You see, what he’s saying is perfectly simple. If now you take your system of material particles, since they’re all relative to each other, you can obviously start what you have to say with any one of them. If you start with any one of them, it will make no more difference with respect to the material system than if you start with any of the others; but if you’re smart, you can pick a good one to start with. All right, what’s he talking about? Miss Marovski, you were going to say something?
MAROVSKI: He’s talking about the origin of vectors.
MCKEON: What?
MAROVSKI: He wants to select his origin.
MCKEON: Select? You mean you want a principle?
MAROVSKI: He wants to find a place for the beginning.
MCKEON: The word principle means “the beginning”; origin means “the beginning.” He is saying that this is the way in physics you find your principles. It has to be with respect to a point that will determine all other points. You take it arbitrarily, but some are better than others. What kind of a principle is this? . . . Yes?
STUDENT: It’s actional.
STUDENT: It’s actional, sure.
MCKEON: It has to be actional. What you’re saying is that you have to pick; you do it.
All right. So we have all entitative interpretations in our last three authors (see table 13). Clerk Maxwell is going back to the operational method of Galileo, with obvious similarities, but he’s carrying the operationalism far beyond what any of his predecessors had done. He is laying down a system in which, by picking the origin, you pick your principle; and you can also then move from one branch of physics to another. Doesn’t this light up anything in your readings? . . . Well, you don’t have to answer that.[L!]
We will go on from this point more rapidly in our next discussion. Read chapters II and III. And if you have any feelings of doubt or discomfort with respect to what we have done in our discussion today, we’ll try to clear them up next time.
