[This is an essay I wrote in 1989 for folks in a physics discussion group I was part of for a while—until I got sick and had to drop out. It was led by Steve Bryson as an adjunct to a short course on particle physics he was teaching at the California Academy of Sciences. The one section on “representation” is—strictly speaking—about an issue in aesthetics, but it is tied in here with the question of whether scientific theories can be truly said to represent the actual physical world.]
I think that most of us in our physics discussion group have been delighted and enthusiastic about how things have been going so far. One of the main reasons why the discussions have been so lively, I think, is that Steve Bryson has selected some very provocative—that is to say thought provoking—questions for us to focus on. At the second session, for example, he raised a number of good questions which I have paraphrased as follows:
I find that these sorts of questions challenge me to work out and clarify my own ideas. In this essay, I’d like to discuss the first four topics above.
This is no doubt one of the most fundamental questions in all of science. To ask it is in fact almost to pose the question which gave rise to the great split between the materialist and idealist world views.
The answer to this question, from the materialist perspective, is that our ideas, or opinions, or views of the world are reflections of the world; that is, they derive from the world and the ways we interact with it. The world exists, matter exists, and we gradually come to know it better because we interact with it in more sophisticated ways. Our experiences, our form of life, the way we exist—and of course the conscious scientific experiments we perform—all go into determining our views. As these experiences and forms of existence develop, and as we (speaking collectively!) perform new experiments, our ideas of the world progress, and (generally) get closer to the truth.
How do we know we are always getting closer to the truth (even if we can never actually arrive at it completely)? Because we can do things now that we could not do before. Our degree of control over the world is increasing. We can make iron tools, build radios, and go to the moon; with our older ideas we could not do these things.
Even the most primitive, “pre-scientific”, views are still a reflection of the world, or at least were originally. At one time (thousands of years ago!) the idea that lightning bolts were the creations of powerful beings in the sky was a reasonable hypothesis. It may well have been the only theory anybody could think of back then. As crude as this theory was, it at least based itself on people’s experience that we have some control over nature, that we can pick up a rock and throw it for example, and that likewise the rest of nature might be under somebody’s control in a similar fashion. (I.e., it was an analogy based on people’s experiences.) It at least implied that things like lightning are not completely inexplicable, but are things which can be caused somehow.
[Aside: The argument has been made that the primary way we come to understand anything is through analogy. As Marvin Minsky remarked: “How do we ever understand anything? Almost always, I think, by using one or another kind of analogy—that is, by representing each new thing as though it resembles something we already know.” Logicians, being mathematicians, or mathematically inclined, tend to greatly overestimate the role of formal logic in our thinking. Furthermore, they tend to imagine that all types of thinking are either deduction or induction. The concept of ‘induction’ is a somewhat misguided attempt to formalize one type of thinking-by-analogy into something like a “deductive” argument. (I.e., the attempt amounts to drawing an analogy—albeit a basically misleading one—between one kind of reasoning-by-analogy and reasoning-by-deduction!)]
The reason why people today with a smattering of scientific knowledge (like me!) can justifiably laugh at the idea of Zeus hurling thunderbolts, and the sun being a bonfire dragged across the sky behind a chariot, is that now we have better theories. It is not so much that the older theories were “foolish”; it is that they now look foolish in comparison with our better theories which are more coherent, of broader explanatory power, better tested, etc. Even our best current theories will also look somewhat foolish (at least around the edges) in the future.
I have been speaking as if all of humanity had the same, collective, view of the world. Of course that’s not true. There are those whose views have scarcely advanced beyond that of a god in the sky hurling thunderbolts. And it is quite justifiable to speak of those whose views have not kept up with the march of science (at least in the main) as “unscientific”. At one time you could be scientific and believe in the phlogiston theory; that is no longer possible.
Even within the “scientific community” there is a wide and diverse range of views deriving from all sorts of social influences. You will find Nobel prize winning physicists who hold the most scientifically untenable and discredited views about the supposed lower intelligence of Blacks versus whites. You will find some scientists championing creationism, and arguing that the world was created just a few thousand years ago, despite the conclusive scientific case against such nonsense.
It has been a long time since it was possible for any one person to have a complete and fully up-to-date scientific view of the world, because science has grown far too large. Because of the backwardness of society, and our miserable excuse for an education system, it is now actually fairly common to find even scientists whose acquaintance with science scarcely goes beyond their own specialty (if that!), and who hold the most unscientific (i.e., laughably obsolete) views in other areas. I know one medical scientist, for example, who believes in shamanism, Tarot card reading, and many similar “New-Age” things.
It is possible, however, for someone to have a basic scientific view of the world, to have some familiarity with the basic current theories and findings in each of the major sciences, and to approach things in general in a scientific way. Certainly a goal to strive for!
We need to separate this question into several versions, some weaker, some stronger:
Well, yes of course. We have to work at understanding the world, and understanding comes in some areas before it does in others. Some aspects of the world cannot be imagined or understood until certain prerequisite aspects are understood. Democritus could imagine a crude theory of atoms, but there is no way he could have imagined quantum chromodynamics.
Nope, can’t be. If that were true, we never could have come to understand anything; science could not have gotten started. Even the most primitive human beings were capable of understanding some aspects of the world. To survive, each creature in the world must be capable of interacting with it with some degree of success. And each conscious creature, in recognizing what it must do to survive, thereby must recognize some truths—even if only partial and one-sided—about the world.
We don’t know yet, and maybe we will never know. In the sense implied in the question, though, I doubt it very much. There is no reason at present to believe that human intelligence is inadequate to the job of understanding nature, at least in its central and basic aspects.
From a theoretical perspective, the only limits I can see are not due to any possible “failure of the imagination”, but rather due to the inherent limitations of any computer, no matter how sophisticated, including the human brain. Computer scientists have described problems which are inherently so complex and computationally intensive that even if every proton in the known universe could be turned into a computer as fast as our fastest Cray supercomputers, and all of them could be made to work together in parallel on the problem, there still would not have been enough time in the 15 billion years since the “Big Bang” to find the solution. But! This is only relevant if it can be shown that understanding some aspect of the way the world works requires us to solve such monstrosities, and so far nobody has come up with any reason to believe this.
Although modern physics is certainly complicated, it would have to be more complicated by many, many orders of magnitude before it exceeded the capacity of the human brain to understand.
Possibly, and for the same reasons as above. But, again, there is at present no reason to believe this.
Someday, if we do not destroy ourselves first, human beings will build what has been called ultra-intelligent machines, i.e., computers that are more intelligent than we are. We will then proceed to connect ourselves up to these UIM’s in more and more intimate ways, so that we can interact with them (via radio transmitters in our skulls, perhaps). It’s my guess that Homo sapiens and the intelligent machines it constructs will eventually merge into a new species of being, and continue evolving in a completely new way (i.e., by self-redesign, instead of through natural selection). Either that, or our more intelligent creations will simply replace us. In either case, the capacity for every kind of intelligence will continually expand in such creatures.
If we do someday reach a level of understanding of the world where we cannot go further or deeper because of the constraints of the computational capacity of our brains/computers, then we will have the option of expanding that computation capacity. Only if the universe turns out to be so complex that no reasonable subset of it can be organized to model the essential features of the whole, will the whole scientific enterprise be ultimately stymied. And there is no reason to believe that this is the case.
This is a pseudo-problem. We are constantly finding ourselves in need of new words and concepts, not only in our attempts to understand and describe the world, but in all our pursuits. When we need a new word or concept, we just invent it. (Or at least the more clever amongst us do, and the rest of us proceed to make use of their inventions.)
Remember, at one time not one single word or concept we have today existed! (At one time even people did not exist; at one time the earth did not exist.) So where did all these diverse concepts come from? We invented them. No big deal.
Any species capable of inventing all the concepts we have invented so far is capable of inventing a lot more. We invent them as we need them, and there is absolutely no reason to think that our inventiveness in this area will ever fail us.
Our experience in interacting with the world is the primary source of our ideas and concepts about the world. And as long as any aspect of the world can be experienced by us, no matter how vicariously, then we can formulate concepts to describe and understand that experience. (If one supposes that there might be “aspects of the world” that are beyond any possibility of experience, then an explanation is needed as to why such a thing is considered an “aspect of the world” in the first place, and not simply a fantasy.)
Of course it is true that certain new concepts we come up with may at first appear quite strange, or even bizarre. But if these concepts are vital, and coherent in terms of our broader theories and knowledge, we will eventually get used to them. (Or at least new generations will.)
The recent history of physics shows there is plenty of imagination at our collective disposal. In fact a case could be made that the problem is frequently in the other direction, that we let our imaginations run too wild. (You may wish to consider my speculations about the merger of human beings and UIM’s, discussed above, as a good example of this in another sphere!) Perhaps what really needs to be done is to focus a bigger share of our imaginative power into designing experimental tests for the theories and concepts that our unbridled imaginations are always cooking up.
This is primarily a question of interest in aesthetics, where in fact it has been considerably discussed. In my opinion the basic answer to the question is that A is a representation of B if and only if
The point of item number 1 is that representations are (typically anyway) visual imitations of some original. The point of item 2 is that there must be a number of important characteristics or aspects of the original that the representation shares (or has an analog for), in a kind of one-to-one correspondence, but that it is impossible to say in the abstract how many such correspondences there must be, or to say in the abstract precisely which corresponding elements are relevant and which are not. (The fact that my painting of an apple and the apple itself both weigh 6 oz., and the fact that they are both sitting on the same shelf, may be true, but are completely irrelevant to my painting being a representation of the apple. These are non-visual aspects; but some visual aspects of the painting may also be irrelevant to its being a representation of an apple.) And the reason for item 3 is that a coke bottle is not a representation of a coke bottle precisely because it is itself a coke bottle.
So, I would say that a painting is a painting of a rose if it is a certain kind of representation of a rose, that is, if there are a sufficient number of relevant aspects of the painting that correspond to aspects of the rose. The things that would count as relevant here are presumably various aspects or features of shape and/or coloration, and their interrelationships.
Well, aesthetics is fun, but what is the relevance of all this to physics? I think that Steve brought this topic up because he wanted to raise some questions about how true any of our scientific models (theories) of the world really are. That is, I think he was trying to suggest that scientific representations of real world entities or phenomena might have little or nothing to do with the way these things actually are. I think he was basing this view on an analogy with aesthetics, where I suspect he takes the view that representation is a matter of the “intent” of the representor only.
Let’s put aside the question of whether Steve actually holds these views (I could be wrong in my suppositions!), and just consider these views themselves, and their implications.
The idea that representation is just a matter of the intent of the person doing the representing is a subjectivist view. It starts from the fact that there are lots of different ways of representing a rose in a painting and jumps to the conclusion that anything in a painting might be a representation of a rose if that is what the painter intended. “Let this black X represent a rose...”
This is a view that deserves extensive criticism, but obviously the place to do it is in a paper on aesthetics, not a paper on physics. Let me just say that I think this view is essentially wrong—though like most wrong views, it has a small element of truth to it. One of the reasons why it sounds as plausible as it does is that it rests on a confusion of the different standards that exist for what counts as a representation within different artistic styles or genres.
In a realistic style, for example, the standards of representation are much stricter that they are in an abstract style of painting. Specifically, a black X is definitely not a representation of a rose in a realistic painting, no matter what the artist intended. At most it might be a symbol of a rose, which is something else.
On the other hand, it is conceivable that a swishy black X might be a representation of a black rose in a painting done in some very abstract style, where the form of objects is nearly abstracted away, and only the colors count, let us say. But even in the most abstract style, if a rose is really to be represented in a work, there must be something about the representation that mirrors the reality.
Thus the view that there need be nothing objective in any representation is wrong. There are subjective elements, both in that the standards of representation can be variously selected, and in that the specific aspects or elements that are mirrored can be variously selected. But those aspects which do get mirrored constitute the objective elements of the representation. The existence of such objective elements is essential to the very concept of representation.
Since representation is not the totally subjective animal that it is often supposed to be, the attempt to show that scientific theories or models are also totally subjective—because they are analogous to representations—also fails.
It is true that there are subjective elements in our scientific theories. That is because we do not fully understand the world. Our views and theories are partial, one-sided, even “half-baked”. But there are also some elements of truth in our theories, some objective elements that mirror the real world. We know this, because our theories can be put to practical use, to change and control the world for our benefit.
The phenomenalistic, or subjective side is there, but so is the objective side. A dialectical appreciation of both of these sides of our knowledge is necessary.