Session One, part 4: The Fundamental Paradox of Late Twentieth-Century Thought
The Fundamental Paradox of Late Twentieth-Century Thought
Before I leave the sphere of Language entirely for today, our first day in “History of Literary Theory,” however, I’m going to ask you to focus with me in a very simple way on something I’ve been touching on repeatedly. It’s the way that human beings, even as newborn babies, possess something that I’m going to call “a set toward systemicity.” Newborns orient themselves to the faces of their birth mothers in the first minutes after birth in extraordinarily detailed ways. This has been closely documented. As soon as babies can focus their eyes (two weeks), they try to follow the trajectories of objects passing through their visual range.
If you think about the explosion of sensory inputs the baby must be experiencing when it emerges from the womb into this external world of light and sound and color and touch…. yet in the midst of this assault of chaotic sensory impressions, the baby already has seems to have an orientation toward “concerted” or “constituted” phenomena, toward “stuff that moves in concert” as distinct from “background.” They also know a lot about language structure and distinguish familiar voices. And the baby is already attending to these things months before it has learned the boundaries of its own body and distinguished where they leave off and the rest of the world begins, a process of separation, by the way, that happens through language, because it is through language that they emerging psychologically as a human “self ” that possesses an “I” capable of “knowing.” [Boy oh boy, do I have something to say about the convergence of Douglas Hofstdler's work and poststructuralism!]
So the human mind is not stocked from birth with Innate Ideas, nor is it a tabula rasa, a “blank slate.” Plato was closer than John Locke, though, because human consciousness does innately set itself toward certain systematicities and orients itself to relevant coherencies, as though this chaotic and changeable world of physical sensations were lit up for us by flashes of white lightning, telling us what to pay attention to. As we notice patternings and fluid or dynamical “moving in concert,” that concertedness is of course not something apparent or apprehendable at any one instant in time. Already we are selecting and comparing and combining sensory impressions across time – whatever time may be – so that “time” is woven in some fashion into all of human “knowing,” from the outset. Language is acquired by human beings only because of this innate genius for orienting our awareness to dynamic coherences and patterns that are both temporal and formal in their constitution.
Furthermore, of course, this means human consciousness has some kind of profound entanglement with time: it is a “time-consciousness.” Time is for human beings always in some sense psychological time (as Augustine knew) – and this statement has nothing to do with it being “subjective” as opposed to “objective” and “external.” (Dated categories, unless they should be redefined and renewed.) Einstein introduced the human observer into physics in a much deeper sense than that; he showed that what we know through physics is always-already what we can know according to our attempts to make measurements, and he realized that this cut the link between genuine human knowing and any claims to an all-inclusive or universal knowing. [N.B. The claims of this sentence to be free from bias have been contested! See comment thread! : ) ]
The discoveries of physics may very well describe “reality.” [Why is reality here in quotes? Not because I doubt that reality is manifesting itself in an ordered way in the experiements and data and theories of physics! But because all of those are still representations of the reality, and by their highly focused nature are representations of certain selected features of the whole of reality. These gaps and qualifications are of vital importance, because they mark an advance in sophistication of the theories.] But we cannot claim that we can know that they do [without noting the mediation of our own efforts to know]. After the twentieth century, every statement of what is known in every discipline must be prefaced with the qualification “for human perception” [or, according to what the observer can measure relative to something -- thank heavens the speed of light is not additive ...] This sort of thing has to be dealt with every single day by physicists in the interpretation of quantum mechanics, where profound philosophical, ontological, and epistemological issues are being dealt with from inside of the narrow framework of a very highly specialized way of knowing. The results are both utterly brilliant and at time quite naïve. [Eech! These were fighting words! Sorry. But isn't this true of every discipline's attempts to deal with the work of other disciplines? I've learned a lot since I first wrote the preceding sentence!] This will hold true to efforts within every discipline, including my own efforts, so it is imperative that we talk to one another.
This kind of characteristically human “set toward systemicity,” it seems, is not operating for the autistic child, who does not make eye contact like other infants and who does not assimilate language in the precocious way that most children do. Temple Grandin, that amazing woman who has revolutionized the way animals are handled in farms and slaughter yards all over the world, explains that having been autistic from birth, she finds that she can readily perceive the way animals are perceiving their environments and recommend changes that would not occur to someone else.
But she has emerged into language and the human world only with the greatest difficulty and the most courageous effort. Most little children, for example, have no trouble with “this is a puppy and it goes Bow-wow.” “This is a kitty-cat and it goes Meow.” But Temple Grandin remembers spending hours as a much older child, studying pictures of dogs and cats, trying to figure out how other people could tell them apart. She finally decided it must be the length of the nose in front of the stop of the forehead. If the nose was long, then it was a dog.
This haunting awareness of “the trees,” so to speak, without being able to perceive “the forest,” is typical of autism. What is perceived is the haphazard concrete, so to speak, and there is great difficulty dealing with identities or classes and kinds of things. The “haptic” art produced by autistic persons is extraordinarily compelling visually, precisely because it is without perspective or a sense of the identities of things as wholes. On the other hand, most toddlers “get” dogs and cats right away – or at least they develop pretty good “working theories” about them very quickly. And then they refine those theories without difficulty. This sort of dynamic formalizing capacity seems to be lacking, to various degrees, in the autistic person.
With autism in mind, then, let’s return one last time for today to the way human consciousness is conditioned by its language very early on, in order to be able to perceive and communicate about the world. By the time we are apprehending words and phonemes and syntax and so forth, we have been fully conditioned to perceive selections and combinations of what is going on in the flow of physical sound, but we are never, on any structural level of our language, interested in all of the sound. A great deal of the empirical and quantifiable flow of sound passes us by as mere “static” or “noise.” It is empirically there, but we don’t notice it. For our deeply conditioned perception, much of the sound is not “there” because it doesn’t signify anything, with respect to the signifying systems we now have in place for making our interpretations. In contrast, then, autistic persons do not readily distinguish between what is to be taken as noise and what is to be regarded as distinctive, in an onslaught of sensory impressions. But most of us can and do, most readily, pick up the signifying clues, however subtle, by developing what we have learned to notice in language into a system that interprets language.
So yes, the world around us as members of a human speech community is a physical or empirical reality, if you wish to call it that. (When I read the Copenhagen physicists I thought they weren’t so sure, but that seems to have changed, perhaps. I’m confused about this and wish someone would help me out.) But we human beings do not perceive the physical reality that is there. Instead we are conditioned by language – and in the same way by disciplinary training and by our culture (which is a fabric of languages or signifying systems) – to perceive certain selective elements of the physical totality, and combine them in certain ways, in order to arrive at communally negotiable meanings, while disregarding all the rest of the physical order. It is not always the most physically prominent elements that we select, either. And we are incredibly good at doing this, which is why our human ways of knowing are so productive and even awe-inspiring. Still, there is so much “reality” going on around us (and inside of us) that we must always be blind to a whole lot of it.
For today, then, I’ll close this consideration of language by simply relating a story told by a high-ranking member of JFK’s cabinet. It will serve as a little parable, an illustration given to provoke thought. The story’s about a dinner at a swanky
Washington DC restaurant in the early 1960s, where the cabinet sat with President Kennedy for hours, discussing the question: “What do black voters want?” It wasn’t until years later that the cabinet member who told this story realized there were as many African-American men in that room as cabinet members. But they were serving as waiters and filling wine glasses and carrying dishes in and out, while the white men one by one gave their opinions about what blacks really wanted. While the African-Americans in that room were physically present, they were as good as invisible, because they didn’t signify. They didn’t “make a difference,” even when they themselves were the topic on the agenda. Now that’s conditioned perception! And future generations will look back on us with the same sense of shock and incredulity over what we aren’t seeing right now.
So there is always more in the flow of sound and more in the world around us than what we are conditioned to perceive and “count” as being significant. This is how our language – like our disciplinary discourse and like our culture as a whole – conditions our perceptions of everything, even while enabling us to share and preserve and enhance our perceptions. Without such sets of limiting conditions, no human community could ever achieve any shared knowledge of their world, or have a communal “world” to share. Nonetheless, these are still limiting conditions.
It seems to me that this is the fundamental paradox of later twentieth-century thought. I am so drawn personally to Derrida and Kristeva because they are always trying to work out ways to negotiate this paradox faithfully and honestly. Here again, though, I must note that this state of affairs – one that psychoanalysis and literary theory have opened up for us as late-moderns – was familiar territory to earlier Westerners. But we’ll consider that more appropriately later, as when we get to Boethius, Augustine, Aquinas, and Dante, for example.
For now, however, we’re just about ready to move on to our next domain of human mystery, the sphere of Art. And if you think language turns out to be a strange and counter-intuitive phenomenon – as soon as we stop simply using it and start looking at its functional structure, or start pondering its origin – wait ‘til we get to art. Well, stop a minute. We can’t leave language, can we, without mentioning the emphasis placed on language and especially on its “naming” capacity, in the magnificent story of creation that opens Genesis, “the book of beginnings.” First, Elohim brings the universe into existence by speaking it. “And God said, Let there be light, and there was light….” This is why the instrumental maker of all things – Wisdom in the Old Testament and Jesus Christ in the New – is associated with the “word of God,” because everything that has being is brought into being through being named. Then the human creature, “made in the image of God,” likewise brings into being by naming, when the living creatures are brought to Adam to be named. After all, Adam is naming the kinds of animals. He is saying “camel” and “donkey” [or puppy and kitty] not “Joe” and “Pablo.” And while the particular animals in the story are physically there in the garden, the “kinds” of animals come into existence, at least for the human perception, by being named as kinds.
But they are named as kinds of things, it appears, according as they have their being as kinds of things. Let’s not fail to notice just how insistent this ancient creation poem is about the way each thing is made by God “according to its kind.” And so it was. “The earth produced vegetation: plants bearing seed in their several kinds, and trees bearing fruit with their seed inside, in their several kinds….” The ancient mystery, then, of how to group the animals into kinds or how seeds grow up into the cedar or the grapevine or the acacia tree…registered as supremely worthy of mention in a mythic, symbolic, larger-than-life narration of the beginnings of things. The same mystery that we probe today as the “information” that is encoded and passed down in DNA molecules.
What we’re going to be seeing when we turn to the Greeks is that these same insights about being human – that humans are able to name things according to their kinds – will come to us also from them. The Western human project of coming to know originates in our ability and desire to name according to their kinds, where naming comes in the Greek tradition to mean finding the logos or “formula” or “account” for each kind of thing. So, from the Pentateuch so revered in the Hebraic tradition, and from classical Greek philosophy – from two very different and ancient and profound traditions of knowing – we find humans knowing by “naming” (which is the Greek word logos) and we find humans knowing by “identifying the kinds” (which is also the Greek word logos, as we shall see). Both traditions are saying: “Here is the place where humans truly dwell.” As late moderns, we are deeply conditioned by our culture to ask, “Who am I?” But we are not necessarily trained to ask the much deeper question, “Who are we?” And also, as the scientistic late moderns we are, we often miss significant revelations because we are trying to reduce everything to a certain kind of fact.
[Please continue to part 5, Our Peculiar Subject Matter, when Dr. Blumberg adds more pages]
April 22, 2007 at 7:22 pm
Incredible!
April 23, 2007 at 8:36 pm
Janet, I have to apologize for not getting in here and making some more articulate comment than “oh, wow!” before this. But the wow, let me assure you, is genuine. You have been talking about this for so long that I (like Caleb) thought, okay, show me the money. And you have! I printed out session one and spent part of my Friday afternoon sitting with a glass of wine and working through it. I have some questions, but for now I simply want to encourage you to keep going. This is just the course I always wanted to take, and didn’t find offered in my program. Even though you’re gearing it toward undergraduates, as we all know really good undergraduate courses and graduate courses don’t differ so much in content as in the level of engagement. And I am engaged. I have a New Yorker article to share with you about language development. I want to know more about the science vs. theism debate. But for now, I really want to “think with you” (I love that) back to the Greeks and see what happens. Bethany
June 11, 2007 at 2:49 am
“Einstein introduced the human observer into physics in a much deeper sense than that; he showed that what we know through physics is always-already what we can know according to our attempts to make measurements, and he realized that this cut the link between genuine human knowing and any claims to an all-inclusive or universal knowing.”
I’ve read a a good deal of the early work of Einstein on the photoelectric effect, specific heats of solids, special relativity, genereal relaitivity, his exchanges with bohr, his famour Einstein, Rosen Podolski paper. There is absolutely no evidence in any of that work in him
realizing “that this cut the link between genuine human knowing and any claims to an all-inclusive or universal knowing.”
A problem with us scientists taking pomos seriously comes with these false assertions that keep bing repeated. Einstein didn’t realize such a thing, and if he did it might be in a not too well known writing (if you point me to it, I would take a look). But as far as what I’ve read of Einstein, which is not inconsiderable, what you assert about Einstein is not true.
I might disagrre s
June 11, 2007 at 2:50 am
I might disagree with some of your thoughts and conclusions, and we might argue about them, but it is increasingly hard to hold a debate when explicitly false assertions and abjudications get thrown around.
June 11, 2007 at 3:04 am
Now
“So yes, the world around us as members of a human speech community is a physical or empirical reality, if you wish to call it that. (When I read the Copenhagen physicists I thought they weren’t so sure, but that seems to have changed, perhaps. I’m confused about this and wish someone would help me out.) But we human beings do not perceive the physical reality that is there. Instead we are conditioned by language – and in the same way by disciplinary training and by our culture (which is a fabric of languages or signifying systems) – to perceive certain selective elements of the physical totality, and combine them in certain ways, in order to arrive at communally negotiable meanings, while disregarding all the rest of the physical order. It is not always the most physically prominent elements that we select, either. And we are incredibly good at doing this, which is why our human ways of knowing are so productive and even awe-inspiring. Still, there is so much “reality” going on around us (and inside of us) that we must always be blind to a whole lot of it.”
with this I agree and think it is true. On the other hand, a lot of the progress in science (and perhaps in other fields, but this I do not know as I am a physicist) has come from people who have concentrated and pointed out ignored parts of reality (ignored because
we were predisposed to not look at them sometimes, nut not always, as other wise they were inaccesible to our senses and more primitive apparatuses) and have demonstrated their important consquences to many different phenomena.
I emphasize that concentrating and drawing importance to previously ignored or previously unknown parts of reality is not enough for success in science, also there needs to be relevance as far as utility or as far as relevance to a large range of nature.
June 11, 2007 at 11:30 am
David, I appreciate you reading section 4 beyond words!
Let’s talk about Einstein. You are unhappy that I claimed Einstein realized “that the observer in SP cut the link between genuine human knowing and any claims to an all-inclusive or universal knowing.” What am I claiming when I say this? That Einstein knew his work preserved the fundamental laws of physics for all observers, and believed this was genuine human knowing. That’s what I’m saying.
He (and the other physicists of his generation) were raised and trained in the Newtonian world of absolute time and space, where every event was laid out on one universal grid, as it were, and they knew that had ended. I’m a historian and also I have read and read what the West was thought before Einstein. And believe me, Relativity and QM made a huge advance in our understanding of the nature of science and human knowing in general, along with Godel’s proof. All of this is discussed in Roger Penrose’s The Road to Reality and my golly, does that guy know his maths and physics!
I’ve now realized that scientists read any mention of enhanced epistemic sophictication in science as an attack on science! They leap to the conclusion that what we really mean is that science is socially constructed and it’s results are illusory. No! I don’t know any postmodern thinker who holds this position! The epistemic qualifications worked out in Relativity and QM makes science even more wonderful and more honest and more legitimate as a way of knowing!
Jacob Bronowsky was another of those world-class physicists among Einstein’s peers and he explains the huge shift beautifully in his Ascent of Man episode called “Knowledge or Certainty?” I think the Copenhagen school especially recognized the shift in the relationship between human beings and the physical world. Method and measurement mediate in human knowing in powerful ways.Scientists are always thinking about the pay-off, the end results, and their validity. Yes! But semiotic theorists are always thinking about mediation and methodology AS METHODOLOGY. To think we are dissing on science is such a misunderstanding.
I think it was George Ellis in a thread over at cosmic variance who gave us a link to the Bronowsky episode on the web and I’ve hunted for it and can’t find it. (I have Ascent of Man in book form.) Can anyone find it?
June 11, 2007 at 1:56 pm
Thanks for the clarification. I agree completely with “Einstein knew his work preserved the fundamental laws of physics for all observers, and believed this was genuine human knowing.”
You also mention the Copenhagen school. My main line of work is in quantum mechanics and quantum field theory. But not for high energy physics, mainly for the physics of materials.
Because of my work, even though I am a theoretical physicist, I am confronted quite a bit with reading, interpreting and vetting experiments and their results. Because of this the Copenhagen school is close to my heart. I would like to add some incomplete and perhaps rambling thoughts on it.
Their relationship I would not necessarily say human beings, but observation, from the physical world. Now, this is a Pandora’s box. Exactly how to draw the line between observation and phenomena is an unresolved problem in quantum mechanics and was not solved by Copenhagen. When the demarcation is clear Copenhagen works beautifully so far.
The attitude we take is a lot of times to ignore the problem of the demarcation. This is naive, but it is not as bad as it seams in the sense that this naive attitude is taken when there is littel doubt that a measurement has taken place. In such a case, it is the most efficient attitude to move our science forward.
Now for the cases in which there is no clear demarcation of where the boundary between observation and phenomena occur, we are in unknown waters and we really don’t know what to do. Usually different experiments are performed until one hits on a measurement that has a clear demarcation or if this doesn’t happen progress stalls.
Because of this situation little progress has been made in solving the biggest problems at the foudnations of quantum mechanics. Hopefully in the future experiment, theory or both would point the way to the solution and to more complete and new knowledge.
June 11, 2007 at 6:01 pm
David, I’m so glad to find out that you have the Copenhagen School near and dear to your heart, because I am so intrigued about them, and as brilliant as their strict science was, I especially admire them for their brave and humane struggles to step back and ponder what QM “means” about the nature of reality, if it is so hard to distinguish exactly where reality leaves off and our observational attempts to know it begin. (My scientists friends have assured me that “interpretations” of that sort are not science per se, but are viewed by real scientists as merely “cocktail party chat.” But it’s that kind of chat that interests philosophical types like me and they were so brave to attempt it. Who’s going to guide the rest of us on interpreting QM, if the QM folks don’t?)
You are saying, if I understood you correctly, that, for the Copenhagen school, the big change or the big “shift” that occurred with QM was a separation not between “human beings and the natural world,” as I had put it, but between OBSERVATION and the natural world, right? (I think a word or two got dropped in your comment and want to be sure.)
That change in terminology is great for me. It does open a Pandora’s Box, doesn’t it? I’d like to ask you two questions.
When you say “observation,” are you physicists thinking that observations are always made or staged by observers? And observers seem to be equivalent with big-brained intentional agents (like human beings but not limited to them)? Or can an observation ever be “purely mechanical”? Where does the collapse occur? If a mechanical device takes a measurement, can we know if the reduction takes place with the mechanical intervention or with the interpretation by the scientist? Maybe this is a silly question? But I’ve never been sure.
My other question is, can you clarify or give examples of when the demarcation between observation and phenomena occurs clearly and “Copenhagen works beautifully so far”? I mean in contrast to a case or two where the boundary hasn’t been clarified as yet? I’ve read Bell and all about EPR and so forth…so maybe I can follow you. An example of how a certain kind of measurement gives a clear demarcation when another one doesn’t?
Also, on Copenhagen interpretations of QM can you particularly recommend things to read? I remember studying “eight interpretations of QM” some years ago and I thought it was in something by Feynmann… Have you seen Whittaker’s book on Einstein, Bohr, and the Quantum Dilemma, by any chance?
June 12, 2007 at 6:53 am
Janet, I will start by the end of your post and then comment on other parts. I have not seen Whittaker’s book. I will think of possible things to recommend, but this is a tough request for unusual reasons. Being a physicist my conception of the Copenhagen interpretation was formed not from reading books on it, but by reading the original literature of quantum mechanics, quantum field theory ,and the reading of quantum mechanics books for physicists. It was also shaped strongly by my work as a physicist. So my conception developed from grabbing bits and pieces from sources not dedicated per se to the Copenhagen interpretation, but dedicated to quantum mechanics, and by my work as a physicist. My conception is also the bare bones version necessary to work as a scientist. Basically, the rules of quantum mechanics, the probability interpretation and the collapse postulate upon measurement. If you wish I can expound as to what each means to me more thoroughly. I will comment on the rest of your comment and try to provide the examples you asked for later today or at the latest tomorrow
June 12, 2007 at 3:14 pm
Let me now go back to the beginning of your comment where you say
“if it is so hard to distinguish exactly where reality leaves off and our observational attempts to know it begin. (My scientists friends have assured me that “interpretations” of that sort are not science per se, but are viewed by real scientists as merely “cocktail party chat.” ”
Well, I don’t know if this is science or not, but is certainly a worry for scientists working in quantum mechanics and this is why the early quantum mechanics worried about such things. It is true that one can do a certain amount of quantum mechanics ignoring some concerns, but they do pop up here and there and especially early on they needed to be understood however incompletely.
Let me explain why the issues of observation required the attention of the pioneers. Before doing so let me state that the demarcation between observation and phenomena is purely artificial in a sense. They are both part of reality, part of the universe and subject to the laws of physics. On the other hand in quantum mechanics(QM), their role is very different. In that sense QM is very different from all theories that came before because even though both observations and the phenomena on which they are carried out, they seem to operate under different rules. They are both part of reality, but they are different. This came out of a long arduous process of making sense of the theory and working out how it explained and predicted experiment.
So in order to see how this came about, let me give some background in quantum mechanics. In the Schrodinger representation, QM is a theory of waves. In this sense it is no different than a theory of sound waves or than Maxwell’s equations for electromagnetic waves. Like any theory of waves when there are restrictions, they can oscillate only at certain frequencies. A couple of decades before when Planck and Einstein became the rebels to fire the first shots in the quantum revolution, they realized that oscillation frequencies correspond to energies of a system. So the first success of the young quantum theory was to account quantitatively for the energies of simple atoms and accurately predict the energies of other atoms and molecules. They accounted for and predicted spectral lines.
Now at this stage, they needed to know what the waves represented, what characteristic of the system under study they described. This was a puzzle, which was cracked by Max Born whose two Ph. D. students Heisenberg and Pauli had already so much contributed to the development of quantum mechanics. He proposed that the square of the waves represented probabilities. This1926-7 insight he based on Einsteins work on the photoelectric effect of 1905. Since Einstein had proposed correctly that the number of quantized particles of light, photons, were proportional to the square of their waves and since the average number is proportional to probability it was a keen insight on Born’s part. Now, it has to be tested against experiment. It passed with flying colors and it keeps passing with flying colors in the countless QM experiments that are run each day in our present world.
Now that we knew the waves had to do with probabilities of events, their square are probabilities a whole lots of questions arose. First of all even though the evolution of the QM waves is fully deterministic their consequence for experiment is not. This is a radical break from all previous understanding of nature. but, here comes the disturbing part, Copenhagen, if the waves are probabilities the include many possibilities. When a measurement takes place what happens to the nonmeasured possibilities?
QM does not say what happens. No one knows. Actually the Copenhagen school made up a rule based on consistency. since the nomeasured possibilities did no occur, they are not there. What to do? By hand we slice the from the QM waves. This is the collapse postulate. We take them away by hand. This is a rule imposed by fiat, outside regular dynamics but without which, there would be no consistency and furthermore we could not predict the probabilities after the measurement since if we did so from the wave without the excised possibilities we would get wrong results.
Now, this is deeply disturbing. We have a theory of physics with a rule imposed by fiat without which the whole edifice crumbles. Does it work? Yes. Do we need it? So far, yes. Does it define what a measurement is? That is when do we apply it? No!
I know I still owe you examples, but I live in Holland and I am falling asleep… I’ll stop here and go on after I hear your comments, objections and qualms
June 12, 2007 at 3:17 pm
Yes, I would love for you to do that!
Can you clarify whether the collapse upon measurement is thought to mean that the collapse “occurs” (whatever that means) with the intervention of the mechanical device or with the interpretation by the (human) observer? Or is there anyway to separate those, since we can’t “know” the machine measured (or what it measured or what happened) until we “know” it, which means we ourselves have gotten the information… have observed a measurement…. Is there a way to get at that experimentally? (More simply, to distinguish observation from human beings observing?)
I’ve been reading Hawking and Penrose and some others disagreeing over superposition and the famous “cat” and also Jacob Bronowski insisting QM means that we must have seek “knowledge” and not “certitude.” Every instrument that shows us more also excludes other aspects we want to know about, in his moving Ascent of Man. I want to say that science and (semiotic) theory have come to a similarly chastened and humbled position: that human knowing has some built-in limitations based on the way we use what is available to get at things, and then we need other things to get at more of it, and that this makes everything more exciting than insisting dangerously on fundamentalist certitude and triumphalism (”this is the ONLY way; we have THE absolute truth”).
Making overstated claims about what we know and how we know it is intellectually unsupportable and our biggest enemy in the political arena. Yet we fear that giving up even an iota of our truth-claims will make us incapable of distinguishing between different positions in the political arena, or between fundamentalism and thoughtfulness. I don’t think is as big a danger as our own fundamentalisms are.
June 12, 2007 at 3:31 pm
Quick before I go to sleep. We can’t know if it is the machine or if it is a human observer at our present stage of knowledge. We cannot know because of the reason you point out. We only now when we go and read the machine, we only know when we get the information. With my scientific background I prefer to think it is the machine. Actually some arguments could be made that it is the machine or the measurement even if it is not done by a machine, but none of them are definitive, and none are proofs. Since for you and I or anyone else to know, a human being to finds out to convey the information it looks that there is no way to know. I say it looks because who knows what progress and knowledge tomorrow will wash ashore?
On the famous cat and other things I’ll comment tomorrow…
June 12, 2007 at 4:11 pm
Okay, that really helps me. And it’s coming from the horse’s mouth, someone who works with this stuff all the time! Thank you so much.
By the way, I got to thinking some readers may be at sea here and that the witty and brilliant Sean Carroll over at cosmic variance had surely written on some of this, so I found this amazing post of his, where he replaced Schrodinger’s poor old cat (that gets shot with a gun, or not, so it’s in “superposition,” not alive and not dead or both alive and dead) with a Cute Puppy in a Box (we just don’t want to wake it up!). For anyone who’s wondering about the Pandora’s Box of QM (quantum mechanics) you’ll enjoy this post as great background.
http://cosmicvariance.com/2006/02/27/quantum-interrogation/
June 13, 2007 at 3:09 pm
Since I’m not a physicist (despite of my affiliation), maybe I should leave it to David. But here is what I wanted to post two days ago, but somehow didn’t work. Take a look at the result of the double-slit experiment at the following link that beautifully illustrates the wave-particle duality and how that relates to observation.
http://en.wikipedia.org/wiki/Double-slit_experiment#When_observed_emission_by_emission
June 14, 2007 at 5:39 pm
Hi, that is an elegant link. Thanks. I’m recommending it tomorrow.
David, Hi, and others, here’s another question, just to make you work! No, seriously, I am curious what sense you get as a particle physicist as to whether a quantum particle’s wave-function is “real.” If you find Copenhagen “works beautifully,” then I think that means you accept as a working formalization that “the wave-function collapses” whenever a measurement (observation) is made.
The wave-function is a probabilty function, right, and so the “particle” is only potentially “there” at any position, and more probably it will be found in one place than another. So why can’t we actually think of it as a potentiality-structure of some kind that covers the whole space of possible locations? Sort of like (just analogy) energy suddenly converting into mass?
At the quantum level, couldn’t things actually “be” continuous and be converted to discreteness by a macro-sized intervention? (Please don’t laugh.)
June 18, 2007 at 6:50 am
I won’t laugh promise! First a small correction, I’m a condensed matter physicist, but in here quantum mechanics and quantum field theory reigns supreme just like in particle physics.
Yes, as far as Copenhagen a macro sized intervention, which as far as we know is the act of measuring, is where a discontinuous dynamical evolution. This seems to be true. The problem some physicists have with this is that it is an arbitrary rule. The rule is stop the quantum evolution, collapse the wavefunction to what the measurement gave you, and go on with the quantum evolution. So the collapse itself is outside quantum evolution. It is like a rule imposed from the outside. This works well, and we (myself included) use the rule all the time, otherwise we could not compare with experiment and from experiments predict the probabilities of new ones, But, it bother physicists because it looks like a rule outside quantum evolution and we this take it as a sign of lack of completeness. But it seems to work.
Yes, you could think of it as a potentiality structure.
The analogy with mass and energy I do not understand as they are not related by any potentiality structure in physics. Mass is energy and the other way around. In fact in Einsteins genera relativity things that don’t have mass and we think as pure energy like light produce gravitational fields according to the mass energy relation and seem to have inertia according to the same relation.
June 18, 2007 at 9:55 am
I am so glad you aren’t laughing. So I’m embravened to make a fool of myself even more!
Given the enormous energy of nuclear fission, for instance, couldn’t you regard a piece of matter as potentially all that energy? Isn’t that a valid interpretation of E=Mc^2 for a physicist? Likewise, isn’t there a way to “collapse” energy into matter in a sense? How did the the energy get locked into the nucleus in the first place?
I think a lot about the different kinds of “possibility” that different fields talk about.
And here’s a question that’s been waiting for you. (And anyone esle out there is welcome to join in.) I just read about a version of the two-slit experiment where instead of a screen behind the slits to catch the particles being emitted with an electron gun or whatever, there is a physicist with either a test to observe particles or a test to observe waves. The physicist does not decide which test to use until after the electron has passed through the plane of the slits.
So this way the test — ie. measurement or observation — occurs after the passage through the slits and yet seems to determine retroactively whether the passage was like that of a wave or a particle, by the test selected. The conclusion was that in this case the measurement determines the PAST! Any thoughts about this? (No one has actually done all these EPR experiments in outer space, right? But they have done equivalents of those in empirical tests, haven’t they? Is this latter experiment an empirical test or a thought experiment?
June 18, 2007 at 12:40 pm
What you say is not wrong per se. but you seem to have a dichotomy between matter and energy. We understand them to be the same thing but in different forms. energy can take the form of matter, heat, light and it changes between one and the other. Now, what I am describing could be taken to be just as a semantic difference from what you say. And in that sense we might be saying the same thing.
There is no direct test to measure waves or to measure particles. the screen or a physicist counts particles. Since all the measurements we perform are by large apparatuses be it screens, physicists or something else, they are sensitive directly to particle properties. They count particles. Now if when the particles or waves, or whatever they are went through the screen there is no way to determine which slit they went through, the wave properties will be revealed indirectly regardless of how or what does the measurement. The wave properties woul be revealed even if we count particles in the sense that the number of particles as a function of position will show an interference pattern.
Similarly if there is way to distinguish which slit the particle went through there would be no interference pattern and we would see no wave properties, not even indirectly. Feynman I believe has good examples and discussions of this.
June 18, 2007 at 1:58 pm
Janet,
Are you talking about “Experimental Realization of Wheeler’s Delayed-Choice Gedanken Experiment” by Jacques et al. (Science vol. 315, 966 (2007))? (You can read a description in the following blog post.
http://scienceblogs.com/principles/2007/02/thought_experiments_made_real_1.php)
I agree with David that when you detect a photon, you are detecting it as a particle and the wave nature is revealed as an interference pattern.
The experiment by Jacques et al. is interesting, but if you think that the measurement determines the past, that is because you are intuitively assuming that the photon must have behaved either as a particle or as a wave.
I came across an essay by Phil Anderson (Nature vol 437, 625 (2005)) which is relevant to the discussion (and is fitting since Anderson is a condensed matter physicist like David).
Anderson wrote on Einstein-Bohr debates:
“In reading about these debates I have the sensation of being a small boy who spots not one, but two undressed emperors. Niels Bohr’s ‘complementarity principle’ — that there are two incompatible but equally correct ways of looking at things — was merely a way of using his prestige to promulgate a dubious philosophical view that would keep physicists working with the wonderful apparatus of quantum theory. Albert Einstein comes off a little better because he at least saw that what Bohr had to say was philosophically nonsense. But Einstein’s greatest mistake was that he assumed that Bohr was right — that there is no alternative to complementarity and therefore that quantum mechanics must be wrong. This was a far greater mistake, as we now know, than the cosmological constant.”
He adds:
“Taking London’s point of view, one immediately begins to realize that the real problem of quantum measurement is not in understanding the simple electron that is being measured, but the large and complicated apparatus used to measure it. This apparatus has all kinds of properties that are not obvious consequences of quantum mechanics: rigid slits, for instance, and a photographic plate that darkens irreversibly where an electron hits it.”
I agree that you need a better understanding of the apparatus in order to really understand quantum measurement. But we also have to remember that there were physicists who try to explain the measurement by thermodynamical irreversible processes. But they realized that they cannot explain negative measurement (in some cases, the detector not detecting the particle is a form of measurement) by such irreversible processes.
June 18, 2007 at 2:21 pm
Do I correctly understand you to be saying that the negative measurement remains a problem for now, even while we need to look closer at the apparatus?
Roger Penrose insists that Niels Bohr’s complementarity principle (that we can/must approach a phenomenon with two incompatible models such as wave/particle, which physicists are in fact doing) is due to something missing in the present state of the theory. He believes that there must an unknown fundamental principle lying deeper than the wave manifestation and the particle manifestation that will explain both of these currently incompatible results — something we haven’t found yet, but that he believes will be found in the future. But he is very respectful of other views, like Hawking’s that it really doesn’t matter, andpatiently goes through all the various aspects (Road to Reality).
So how can Anderson announce that the complementarity principle “as we now know, was a much greater mistake” than Einstein’s rejection of his own cosmological constant (which just recently turned out to be so presciently correct after all)? Doesn’t this seem a little extreme, compared to Penrose’s magnificently calm and detailed and honest survey of the situation of the present knowledge in QM? Has Anderson discovered something monumental, all of a sudden, do you think? You seem to be suggesting he is a bit extreme….
June 18, 2007 at 9:37 pm
“Do I correctly understand you to be saying that the negative measurement remains a problem for now, even while we need to look closer at the apparatus?”
I have to give an disclaimer that I’m not an expert and much of what I know comes from reading popular books.
Measurement often involves irreversible processes to amplify the signal. It was an appealing idea that this is related to the “collapse” of the wave function, which also appears to be irreversible. But you can consider situations where not detecting a particle is as good as making a measurement. In such a case, the particle is not interacting with the apparatus and therefore the irreversible process is not happening. Therefore, such irreversible processes are not sufficient to explain the measurement.
I still think that you need some sort of quantum mechanical description of the apparatus to fully understand the measurement. But it also has to explain the negative measurement.
Phil Anderson is interesting. He is a true giant. If he is not widely known, that is because there is a reductionist tendency to worship particle physicists as working on more “fundamental” problems. Anderson, as Sean Carroll puts it, “takes a certain pleasure in tweaking the noses of his friends on the high-energy/astrophysics side of the department.” It seems he likes to be provocative. (Remarkably, he even made a great contribution to particle physics by proposing an idea that lead to what is known as Higgs mechanism. Now particle physicists are trying to find the Higgs particle.) Anderson did many great works studying complicated systems, so he has earned the right to emphasize the mystery and importance of complicated macroscopic systems.
I don’t know enough about Bohr’s philosophy, but I don’t get the impression that he was the most rigorous thinker. In fact, I think that the Bohr model is a kind of idea that a more cautious scientist would never propose. It was important because a bold radically new idea was wanted in a period of transition. But it wasn’t a model that made too much sense and it had to be replaced by more complete theories of Heisenberg and Schroedinger. Bohr was great and influential, but that doesn’t mean that we have to agree with Bohr. I don’t necessarily think that the Copenhagen interpretation represents only single philosophical position. What it offers is a simple practical rule to apply quantum mechanics that has been verified by experiments.
I don’t really understand Anderson’s objection to complementarity principle. I can only guess and I could be completely wrong. In experimental situations that we’ve been talking about, we learned that an electron or photon can behave as a particle or as a wave. But do we really see a situation when the electron or the photon behaves both like a particle and a wave at the same time? Even in the delayed-choice experiment, isn’t it most natural to consider the photon as a wave until it is detected?
June 18, 2007 at 9:46 pm
Thanks,this is a lot to mull over. Fascinating about Anderson. My head is full for today…. More later.
June 22, 2007 at 6:05 am
Hi Everyone,
I just read this series of posts and wanted to weigh in on a couple of points. I’m a recovering string theorist who now teaches high school, and I devote a great deal of my time to making cutting edge science accessible to my students. I hope that some of that effort comes through in this post.
The mass vs. energy issue is one that I understand very well, and can teach to my students completely in two lectures, but I won’t try to do it here unless someone really wants the details. The basic idea is that almost every time you think of mass you should really be thinking about energy. For example, we usually write the formula for momentum
p = mv,
but the correct formula is
p = Ev,
where E is the energy of the thing (including its “rest mass energy”). SWith this formula it is obvious that photons can have momentum even though they don’t have mass. You can also see with this formula that as you have a particle going near the speed of light, so you can’t increase its velocity, giving it more momentum (by applying force, which always changes momentum) will still increase its energy.
(I’m using units c=1, which means distance and time are both measured in seconds and energy, momentum and mass are all measured in kilograms.)
Similarly, mass is not what causes gravitational fields, energy does. In Einstein’s equations, the curvature is related to the stress-energy-momentum tensor, not to mass.
It is good that energy is used in all of these areas because energy is a conserved quantity (warning: GR makes this a dangerous statement) so we can track energy much better than mass.
The only thing mass is good for is relating energy to momentum for individual objects via
m^2 = E^2 - p^2,
which gives E=p for massless objects (like photons) and E = mc^2 + 1/2 mv^2 for objects going much slower than the speed of light. (Deriving that last equation requires expanding in powers of p.) Mass is not conserved in interactions. You can’t say anything very useful about the total mass of interesting systems. Its good for one thing and that’s it.
Finally, Janet says:
“He (and the other physicists of his generation) were raised and trained in the Newtonian world of absolute time and space, where every event was laid out on one universal grid, as it were, and they knew that had ended.”
I disagree. Before special relativity everything was laid out on a three dimensional grid and assigned a time. The three dimensional grid was not absolute at all. It could be rotated in three dimensions, and it could be given a constant velocity. (Technical note: That is three rotational degrees of freedom and thee velocity degrees of freedom for a total of six way that space was not absolute.) Space was not absolute before special relativity, but time was.
Special relativity replaced the three dimensional grid and absolute time with a four dimensional grid. This grid could be rotated in four dimensions (Technical note: In four dimensions there are six rotational degrees of freedom, exactly the same as before relativity.) These four dimensional rotations include the three dimensional rotations as well as boosts, which give a constant velocity to the coordinates but also mix time with the spacial coordinate in the direction of that velocity.
Relativity removed the idea of absolute time, but it did not get rid of the idea of absolute space because there was no such idea and it didn’t add any new freedom for different observers to pick their own coordinate systems, because all of that freedom was already there.
Quantum mechanics is much more difficult. I’ll work in it is a separate comment.
June 22, 2007 at 9:23 am
Okay, this is great! Thanks so very much, Gavin. Can you put those two lectures on a link for us, maybe?
Your description of the Newtonian “grid” certainly makes it rotatable and non-”absolute.” This helps me understand why Newton himself and other Newtonians made a distinction between “absolute” space and regular space, which has always puzzled me. But Newton did say in Pincipia that “absolute time and absolute space flow eternally from the throne of God” (close paraphrase from memory).
Every physics book points out that Gallileo knew about relativity in a simple sense. Your comments help me start to see why Newton thought it necessary to distinguish his absolute space from the regular space physicists actually worked with (in his day they were still “natural philosophers” and the word “scientist” wasn’t even used yet).
But whatever content the notion of absolute space had in Newton’s mind (?) it was culturally this absolute time and space that went into the Modern West’s Newtonian worldview of the clockwork universe and how human minds could acheive a god’s eye view of the way things “really are” in the shape of finished, absolutized “facts” about an eternal steady-state unchanging universe. With an “absolute” determinism, as far as physical bodies go.
Hence, the human mind becomes detached from nature and endowed with this absolute autonomy and godlike freedom of the will. (Here we go again. The Cartesian paradigm that we cultural theorists are so adamant about decrying. It would be okay if it were only historical, but it is alive and well in the many/most minds of North Americans today and guides their politics and voting…
Does this make any sense? (Scientists look at the actual working physical theories while cultural theorists are tracing the cultural mindset that accompanies the theories, and the two influence one another but are definitely not the same thing formally speaking, or in terms of the details.)
What do you think? (The speed of light being absolute with respect to every observer isn’t much of a change? I’m teasing, but this does mean something quite significant, doesn’t it? How to characterize THIS?)
June 22, 2007 at 9:32 am
“Absolute time and absolute space flow eternally AND CHANGELESSLY from the throne of God”! — Newton in Principia.
June 22, 2007 at 10:18 am
“Hence, the human mind becomes detached from nature and endowed with this absolute autonomy and godlike freedom of the will.”
In what seems to be a growing stream of Catholic moral thought, following Servais Pinckaers and his “Sources of Christian Ethics”, they too decry what they see as a claim of “absolute autonomy and godlike freedom of the will” (Pinckaers terms it “freedom of indifference”) that they see in modern (or enlightment) thought. But they blame in on the nominalism of William of Occam, not Descartes.
June 22, 2007 at 12:03 pm
Yes, yes, yes. Thanks for bringing nominalism back into my mind. And for the hint to see Pinckaers (whom I’ve never even heard of! good grief!). I’d forgotten the nominalists, and how they were often seen as the origins of bad (autonomous) humanism (as opposed to Christian humanism, which certainly was a humanism integrated with theism and one that has a long and marvelously rich history including Shakespeare and Milton).
If you’ve seen my Kevin Hart post, you’ll know too — or you already know — that Hans Urs von Balthasar (may his name be blessed — what a sweet man!) traced the break (away from the traditionally Christian finite and situated and dialectical human mind, to the Cartesian “absolute mind”) in Duns Scotus! And Duns Scotus was indeed the basis for the theology of the Counter-Reformation theologian Suarez, whose work dominated the Jesuit school in La Fleche where Descartes attended!
I’m fascinated by this. If you read medieval theology on God and mind and knowing and then you read Descartes, he is coming from a different planet! The degree of originality and differentness with Descartes is just astronomical. Especially this sudden hunger for “absolute certainty”….
PS I want everyone to know that Gavin has a new comment over in Section # 4….
June 22, 2007 at 3:14 pm
Janet,
I’d like to connect three comments that you make. I think this post is going to be somewhat blunt, possibly even rude. However, I think that there is a commitment to understanding here, so I’d rather be clear than polite. I’m not a gifted enough writer to do both, so I apologize in advance.
David was critical of your original post where you said,
“Einstein introduced the human observer into physics in a much deeper sense than that; he showed that what we know through physics is always-already what we can know according to our attempts to make measurements, and he realized that this cut the link between genuine human knowing and any claims to an all-inclusive or universal knowing.”
His criticism was right on the money. Einstein did not introduce, show, or realize anything like that.
You then say,
“I’ve now realized that scientists read any mention of enhanced epistemic sophictication in science as an attack on science! They leap to the conclusion that what we really mean is that science is socially constructed and it’s results are illusory. No! I don’t know any postmodern thinker who holds this position! The epistemic qualifications worked out in Relativity and QM makes science even more wonderful and more honest and more legitimate as a way of knowing!”
I cannot say what scientists in general read, but I can say how I respond to statements like the one you made about Einstein. I don’t see an attack on science, I see an attempt to hijack the credibility of science. I think your comment to my last post clarifies how this is done:
“Scientists look at the actual working physical theories while cultural theorists are tracing the cultural mindset that accompanies the theories, and the two influence one another but are definitely not the same thing formally speaking, or in terms of the details.)”
I agree with this, but it is often brushed aside, in part because few people appreciate the huge chasm between advances in science and the cultural responses. To a scientist, the cultural response appears to be totally independent of the actual advance, and almost totally dependent on the vocabulary and analogies chosen in articulating those advances to the public.
A scientist might say, “Einstein showed that a head-on, inelastic collision between identical objects going .6c and .8c will result in something going .2c, not .1c as Newton thought,” when in fact he means that using the theories articulated by those people gives the claimed result. Of course we have no idea whether Einstein or Newton ever did that exact calculation, but their theories are totally clear about how to do the calculation, so to say “Einstein said this while Newton said that,” is pretty precise.
However, when discussing the cultural ramifications, it is common to see comments like “Einstein put perspective squarely in the equation,” when in fact this means that after someone with a basic understanding of Einstein’s theory tried to put it in non-mathematical, metaphorical terms, that paraphrase was seized upon by someone who didn’t understand the theory at all, but was inspired to make a claim analogous to the metaphor in some unrelated field. The statment that Einstein demonstrated this claim is absurd.
I can certainly understand the temptation. My wife might not be persuaded if I say “I’d like to get an iPhone,” but how could she argue if I say, “Einstein demonstrated that it is always-already known that I must get an iPhone”? If “since 9/11″ is the automatic get-out-of-jail-free card for sloppy logic in political circles, “Einstein showed” and “quantum mechanics teaches us” play the same role is certain areas of academia, as well as in new age thought. They are hugely effective in this capacity because the theories carry unassailable credibility while being understood by almost no one. If you base your claim on Einstein or quantum mechanics, who can argue with you? Only scientists, who can be dismissed as arrogant.
When people claim that science says things that it does not say, that is an attack on science because it undermines science’s credibility. That frustrates me.
I’d like to write some more posts like the one I wrote about special relativity. My goal is to express exactly what these theories show, so we won’t be fooled when people say that relativity and quantum mechanics say things that they don’t. In the completed post I tried to show that special relativity changed the way physicists think about time and mass. That is a big deal in a physics sense, but it really is nothing philosophically. It doesn’t introduce relativism or perspective or cut any sort of epistemological link, even if people who heard rumors about this theory were inspired to do those things.
To address your question, “The speed of light being absolute with respect to every observer isn’t much of a change?” No, it’s not much of a change. It is a rather mundane consequence of the four dimensional rotations. It doesn’t have any effect on perception, determinism or the “absoluteness” of how we view the world. It may have caused non-physicists to change their views on those things, but that is not a consequence of the actual physics.
I’d like to address quantum mechanics next. There are three things in quantum mechanics that people use to justify all sorts of non-physics claims: the Heisenberg uncertainty principle, wave particle duality, and the issues of quantum measurement. The uncertainly principle can be seen in waves on a beach, it is not a fundamental new feature of quantum mechanics. Wave particle duality as an obvious consequence of the quantization hypothesis, which is not profound. Only the measurement issue raises big questions that need to be addressed. I think significant progress is being made in addressing those questions, largely by people studying quantum computing, where one cannot engage in sloppy thinking about quantum mechanics.
June 22, 2007 at 6:24 pm
I really appreciate your honesty, Gavin. Without it, I don’t see how we can make any real headway in cross-disciplinary understanding. I don’t think you were rude at all. Honesty is the best gift we can give each other.
I would like to know what some of the rest of you might say about what Gavin just said. Do you all agree with him?
Also, Gavin’s clarification (I won’t call it a rebuke, though it is one! — and that’s okay) elicits these follow-up questions from me.
1) Is there simply NO justification at all for seeing Relativity and QM as constituting a large paradigm shift in science, and one that might be tied in with other shifts in other fields and related to general cultural changes in any rigorous or exact manner? (If there is no strictly scientific justification, does that necessarily mean there cannot be any justification for such judgments coming from other fields?)
2) What about the shift from a steady-state and highly deterministic universe to a probablistic and evolving universe, for example? Is such a generalization as the previous sentence in some sense extra-scientific? Outside of science? Illegitimate, scientifically speaking.
3) Should we say that no changes or discoveries in science are ever PROPERLY culturally significant, but have only scientific significance? If they do seem to have a cultural effect, is that always only by being popularly misunderstood or hijacked by sloppy thinkers? (Think of the profoundly darkening effect of entropy and the heat death of the universe on the later nineteenth century, for example.)
4) When we go to the scientists to tell us what interpretations we should NOT make, to avoid the trap of misinterpretations on the part of non-specialists, what do we do when the top physicists do not agree?
In a way, Gavin brings us back to a basic fact. We thhink diffeently in different disciplines. My theoretical physicist colleague and friend Jim Crichton warned me, saying “Janet, always remember that for physicists, it is the math and the experiemental results that are the science. Any talk of philosophical interpretation or the larger nature of reality is for us just cocktail party chatter. It is mildly interesting to us, but nothing very serious, because it can’t be scientifically grounded the way the math and the experimental finding themselves can be.”
(I have to add that no one kept up with philosophy more than he did and his passing from cancer deprived our campus of a liberal arts stalwart. He also wore a T-shirt that said: “A theoretical physicist is simply the universe’s attempt to know itself….”)
In any case, I welcome the forthcoming explanations of QM that you offer, Gavin, and I will think a lot about the explanations you have already
offered.
P. S. I’m just not wholly convinced yet. We need a historian of science here, but my sense about Einstein, Bohrs, Heisenberg, Bronowski and everyone else during those Copenhagen decades was that they all had a significant sense of the ground shifting under science.
Maybe I am not saying it right about Einstein, folks, but I think there is something there, and it can’t be just that we have a whole passel of historians, philosophers, cultural theorists, and New Agers maliciously hijacking science and ruining its credibility with sloppy talk. (I’m not denying that this hijacking and sloppiness does happen; I’m a poststructuralist and we are totally misunderstood and slandered all the time!)
After all, remember, Gavin, it doesn’t affect science’s credibility as science, to us, when we want to talk about additional metatheoretical and cultural and historical issues with regard to science…. But to you this diminishes the true credibility of science, which you are committed to defend and explain. I get that. Good for you.
June 22, 2007 at 8:15 pm
I don’t plan to make rants a regular component of my comments, but before I get back to what I actually know, I’ll just say that certainly quantum mechanics represented a major shift in the foundations of science, due entirely to the measurement issue. Special relativity and general relativity were bold new theories, but didn’t represent new foundations. They are totally deterministic, clockwork universe type theories (except GR has singularities, which we aren’t quite sure what to do with).
I don’t have a digital form of any of my lectures that I can link to. I’m working on that, but it will be several months before I have much useful.
The Heisenberg Uncertainty principle is what I really want to talk about. Imagine you are lying by the sea listening to the waves break on the shore. When a boat goes by its wake makes waves which you can also hear breaking with a different rhythm. Can you accurately describe both the rhythm of the boats wake (its frequency) and the time that it broke on the shore. Yes, but there is a limit. If you want to measure the frequency accurately, you need to hear at least a couple of waves break. The more you hear, the more accurately you can describe the frequency. However, if there are a lot of waves breaking then the arrival of the wake is taking a long time. It becomes less clear what time you should use to describe the arrival of the wave. As the rhythm get longer you can describe the frequency more accurately and but the time less accurately. If the rhythm get short then you can describe the time accurately, but not the frequency. All of this can be put on rigorous mathematical footing and you get an uncertainty relation
df dt >= 1/(2 pi),
where df is the uncertainty in the frequency, dt is the uncertainty in the position and >= is a “greater than or equal to” sign. (Notice that the units work out nicely.)
Would you be able to do any better if you went out and looked at the waves rather than listening to them? Now you can measure the wave length (or its reciprocal, the wave number, n) and the location of the wake. However, if you want a good value for the wave number, you need lots of waves which will give you an uncertain position, but if you have a tight position, then there aren’t many waves and the wave number is uncertain. So again you have an uncertainly relation
dn dx >= 1/(2 pi),
where dn is the uncertainly in the wave number and dx is the uncertainty in the position.
The conclusion is that wave give uncertainty relations. Uncertainty is not a consequence of quantum mechanics. Does that mean that waves breaking on the shore demonstrate the in some way ultimate truth is not only unattainable but actually nonexistent? Opps, that’s not my field.
To make the uncertainty relations above look like Heisenberg’s, we need the quantization hypothesis. This states that the energy in something with frequency f is quantized with energy levels spaced E=hf apart. Similarly, the momentum in something with wave number n is quantized in momenta of steps p=hn. Multiplying the relations above by h and substituting the quantization hypothesis formulas gives the usual relations,
dE dt >= h/(2 pi),
dp dx >= h/(2 pi).
Now that we have these nice relations it is reasonable to ask why they apply to something like an electron, which doesn’t appear to be a wave. It applies because the electron is a wave. It is actually a quantum excitation of a wave. The wave obeys the first set of uncertainty relations above. The wave can only be excited in amounts given by the quantization hypothesis, so these excitations (which we also call particles) obey the second set of uncertainty relations.
It may be a few days before I can post again. I’m leaving town tomorrow, but I may get something out in the morning.
June 22, 2007 at 8:57 pm
Okay, great.
One response though.
You say: “Does that mean that waves breaking on the shore demonstrate the in some way ultimate truth is not only unattainable but actually nonexistent? Opps, that’s not my field.”
Now see, this provokes in me the same sense of the credibility of poststructuralism being hijacked by sloppy thinking that you complained of in my statements about Einstein and Qm.
I mean, it really makes me want to go on the warpath!! (Calm down, girl.)
To my ears, when people tell me that my own field’s rigorous theory means that “absolute truth is unknowable or does not exist,” they are saying that the standard for truth is (of course) “absolute” truth and any other more qualified definition (or understanding) of truth is merely subjective, personal, arbitrary, or relativist twaddle…
Actually, we scientists and theorists mirror each other more than I had realized! But I want to say that genuine, high-level postmodern thought does not amount to relativism or subjectivity or the loss of truth — and that when people imply this they are unknowingly thinking very sloppily and not really grasping the theoretical details at all. So I feel EXACTLY like you scientists generally do about the credibility of my discipline being “abused” (to use Sokal’s term about PoMo’s “abuse” of science).
Sometimes it’s hard to read the tone, so please realize that the above remarks I just made are not meant to be snippy or acusatory. I’m being honest about how that comment of yours strikes me, even though you say it in passing, because everyone says it over and over again. From within my discipline it seems ludicrous that people interpret our work this way. So I guess I have to empathize with y’all more.
June 23, 2007 at 6:27 am
Janet,
Thank you for responding to my passing remark. I’m sure you hear remarks like mine all the time. They are condescending and ignorant. They show no understanding of what your field actually entails and simply treat the vocabulary as the ingredients of a word salad that can be thrown together in any roughly grammatical way to produce pseudo-profound mumbo-jumbo. I’m sure it is grating.
People who study relativity and quantum mechanics (as well as other areas of science, like evolution) experience something very similar. The difference is that the tone is generally respectful, even admiring. However, the ignorance and sloppiness is the same. Many people think they can engage in a conversation about what some theory shows even though they don’t know what the theory is. The language of all of these theories is math. Anyone who doesn’t know at least the basic math required to formulate the theory is like the person who learned literary theory from cartoons in The New Yorker. I don’t know what “always-already known” means, but I can pretend to know and stick it into philosophical sounding sentences. Most people don’t know what the uncertainty principle actually is, but they can pretend and stick it into sciency sounding sentences.
The good news is that the math of special relativity is quite basic, just algebra. There really isn’t anything preventing anybody from learning the details of the theory. I think everybody should learn special relativity; it is a dream of mine. General relativity is much harder, because it requires some differential geometry, but the committed non-scientist could get a pretty good understanding. Quantum mechanics can be pretty well understood with matrix multiplication, which is a lot easier than calculus. However, with quantum mechanics knowing the math doesn’t seem to be enough to understand what is going on. People who have mastered the theory are still prone to talking gibberish about what it means. When I figure out why, I’ll write a book.
June 23, 2007 at 7:44 am
And I thought you said that you weren’t eloquent!
June 23, 2007 at 10:11 am
I don’t have much to add at the moment, and agree with Gavin.
June 23, 2007 at 8:44 pm
Alright then, wave-particle duality is next. After that maybe David and I can argue about the interpretation of measurement in quantum mechanics using actual equations. How about it, David, should we show them how it’s done? I’ll take decoherence if you want to do Copenhagen, but I could go either way. I won’t do sum over histories, though; I don’t get it.
In my last physics focused post I mentioned the quantization hypothesis. This hypothesis preceded the complete quantum theory, which has quantization as one of its consequences. Although it would be best to describe the full theory, it is quite amazing how much can be done using just the quantization hypothesis. In particular, the essence of wave-particle duality can be understood from this hypothesis.
The hypothesis states that anything that vibrates with frequency f has discreet energy levels with spacing E=hf, where h is Planck’s constant (which in usual units is very, very small.) Consider a tuning fork with a frequency of 440Hz. If you hit it hard it will have lots of energy in its vibration, and it will gradually lose that energy and get quieter. The quantization hypothesis tells us that the loss of energy happens in steps of size E=hf. The energy will step down and step down until the it reaches the lowest possible energy, the ground state. (This ground state only occurs if the tunning fork is very cold, but that issue is unimportant here.) If you try the same trick with a higher frequency tunning fork, then the steps will be bigger (E=hf gives bigger E for bigger f). If the frequency is lower, then the steps are smaller. For all tuning forks, however, the steps are too small to be noticed. It is only with very high frequency vibrations the steps become big enough to be noticeable, for example, in the internal vibrations of molecules. These little steps of energy are called quanta, and they give quantum theory its name.
Now we can consider something more complicated than tuning forks. Let’s consider the electromagnetic field. This field can vibrate also, but the vibrations move, they are electromagnetic waves. These waves come in any frequency, different frequencies being associated with different wavelengths. ( lf=c, where l is wavelength and c is the speed of light.) Once again we can apply the quantization hypothesis, E=hf, and find that each frequency has steps in its energy, these steps are still called quanta, but they are also called particles. When you put one quanta of energy into a particular frequency oscillation of the electromagnetic field, that is a particle called the photon. Often people say that sometimes a photon behaves like a wave, and sometimes like a particle, actually a particle is a quantum excitation of a wave. It’s not either/or, it’s both. That is wave particle duality.
All of the other particles come about the same way. Electrons are the quanta of energy in the various frequencies of the Dirac field. This field is strange because it will only allow one quanta in each frequency (like a tuning fork that could only hold one quanta of energy). Other particles are associated with other fields. This is what quantum field theory is all about.
There is one especially cool trick with this that David will know about. In a material there are vibrations that we call sound. These vibrations have frequencies, so they obey the quantization hypothesis, giving rise to sound particles called phonons. Phonons are actually particles that have been extensively studied. They only exist in a material, because sound cannot travel in a vacuum. They play an important role in many superconductors and in heat capacity and conduction, but I like them just because I think its neat that sound is a particle too.
Now, there are some complicated issues. In particular, there are localized jiggles in the electromagnetic field that don’t have a specific frequency, so they give rise to particles which don’t have a specific energy. These excitations are superpositions of excitations that do have specific energy, so when you produce one type you may measure the other type. But this is a measurement issue, which, as I’ve stated before, is where the weirdness is in quantum mechanics.
June 23, 2007 at 10:07 pm
“Often people say that sometimes a photon behaves like a wave, and sometimes like a particle, actually a particle is a quantum excitation of a wave. It’s not either/or, it’s both. That is wave particle duality.”
…a particle is a quantum excitation of a wave…. This sounds nice, but I don’t know what it means. I get the quantum part, but “excitation of a wave”? And what happened to the collapse of the wave function? (Is this the measurement problem you refer to, or do you mean a different special case where the measuring device interferes with the wave?)
When the photon (or electron or other particle) hits a screen, it “pings like a pebble hitting the side of a car,” as one article put it. In other words, it always lands like a “solid” particle (even though it is the excitation of a wave). But in the two-slit experiments, it’s where the particle lands that’s the issue? With one slit closed it hits probabilistically somewhere on a trajectory through the open slit, but if both slits are open it lands probabilistically somewhere consistent with the interference fringe pattern of a water wave parting to go around a rock and then coming back together to make an interference pattern.
So if both slits are open, you observe an different probability and location distribution, from if only one slit is open. So are there two different wave functions, depending on one slit or two?
And so far, is there no weirdness in your view? Or is that the weirdness, just above? Can you tell it like a story with a gun emitting a (what?) excitation of a wave at a certain quanta level and then….
(If I get this clear, then we can discuss the beam splitter experiment with the retroactive effect.)
June 23, 2007 at 10:10 pm
“Phonons are actually particles that have been extensively studied. They only exist in a material, because sound cannot travel in a vacuum. They play an important role in many superconductors and in heat capacity and conduction, but I like them just because I think its neat that sound is a particle too.”
Yes, I think this is cool too. (I take it that this kind of wave, moving through a material, doesn’t exhibit the paradoxical behavior of the wave/particles that move at the speed of light?)
June 24, 2007 at 4:40 am
Janet,
Good questions. I’ll answer your second question first. Phonons travel at the speed of sound, rather than at the speed of light, but aside from that they have all of the same sorts of features at photons. For example, they can be detected with a counter (like pebbles hitting the side of a car) and they can produce interference patterns. All of the crazy experiments that are discussed with light could be done with phonons (double slit, delayed choice, quantum erasure, etc.). Also, the electromagnetic force can be described in terms of virtual photon exchange. Virtual phonon exchange also describes a force. This force is attractive for electrons in certain materials. This attraction plays a crucial role in superconductors.
June 24, 2007 at 6:50 am
Janet,
The photon is a quantum excitation of an electromagnetic wave. This wave has nothing to do with the wave function. The electromagnetic wave is similar to waves that you are used to, but the wave function is a very strange beast. I haven’t talked about the wave function at all, and also haven’t talked about its collapse.
When you try to measure the position of a photon, you are doing something that is rather contrary to the nature of the photon as I have described it. Waves don’t have well defined position, they are spread out all over the place. The photon, which is an excitation of this wave, is also spread out, so measuring its position leads to all of the measurement issues that make quantum mechanics weird.
But don’t worry about that yet. First be sure you understand the uncertainty relation and the quantization hypothesis. When I get back from my trip (Thuesday or Wednesday) then I can attack measurement.
June 24, 2007 at 7:24 am
Janet,
As Gavin said, phonons exhibit the same wave particle duality as any other quantum wave. Moving at the speed of light or at the speed of sound or any other speed has nothing to do with the apparently paradoxical wave particle quantum duality. In fact one could do almost all of the quantum mechanics and quantum filed theory of materials in a world where relativity wasn’t true and it would come out the same.
This was recognized early on because the shortly after Einstein did his work on the quantization of photons and the photoelectric effect, he applied similar reasoning an methods to the quantization of phonons to explain why specific heat of solids (how the solid absorbs heat basically) goes to zero with temperature. All was done pre 1910. If phonons were not quantized the solid would absorb heat at a constant rate at all temperature. If they are quantized when the temperature became small enough that it didn’t have enough energy to excite a sound quantum, the solid couldn’t absorb heat and it’s specific heat would go to zero.
The advice is to not mix things. Wave particle duality is about quantum physics and does not have to do with relativity or the speed of light.
This does not mean that interesting things do not happen when we mix relativity with quantum mechanics. They do happen, but that is a separate thing.
Gavin, I will be more than happy to run a discussion on measurement. I’ll wait for you to get back from your trip and fire the first shot.
June 24, 2007 at 7:28 am
Janet, just like you take phonons to be kind of waves moving through a material, you could take photons to be kind of waves moving through the universe. ;-)
They are the same.
June 24, 2007 at 11:08 am
I missed the dialogue between Gavin and Janet the last few days, but it’s great. Gavin, who has better understanding of physics than I do, expressed more precisely and eloquently the frustration that I also share.
I started reading David Lindley’s “Uncertainty” as it was mentioned in Chad Orzel’s blog and the discussion here made me curious about the way Bohr and others thought.
http://scienceblogs.com/principles/2007/06/uncertainty_by_david_lindley.php#more
I haven’t even got to the QM part of the book yet, but I already encountered a sentence that express my feeling in a concise way.
“Relativity, to be sure, allowed for differing perspectives, but the whole point of his theory was that it allowed apparent contradictory observations to be reconciled in a way that all observers accept.”
Let me try to respond to Janet’s questions.
Question (1) Is there simply NO justification at all for seeing Relativity and QM as constituting a large paradigm shift in science, and one that might be tied in with other shifts in other fields and related to general cultural changes in any rigorous or exact manner? (If there is no strictly scientific justification, does that necessarily mean there cannot be any justification for such judgments coming from other fields?)
My response to Question (1):
This is a difficult question to answer, because I’m not a historian of science or a philosopher of science. There were a lot of big paradigm shifts in 20th century science. I don’t know whether they are related enough to be part of a large paradigm shift.
Take a look at the field of molecular biology as an example. Many of the scientists involved in founding this new field were physicists. Many were influenced by Schroedinger’s book “What is Life?” In the case of Max Delbrueck, Bohr’s speculation that complementarity argument might have applications in biology had a big impact on him.
Delbrueck did end up doing great works in molecular biology, but equivalent of complementarity was not found in biology. On the other hand, it almost seems that the success of molecular biology owes a lot to the arrogant confidence of physicists who believed that they can understand life by applying their approach. (And being a molecular biologist, I am part of this.)
Question (2) What about the shift from a steady-state and highly deterministic universe to a probablistic and evolving universe, for example? Is such a generalization as the previous sentence in some sense extra-scientific? Outside of science? Illegitimate, scientifically speaking.
My response to Question (2):
Being steady-state and deterministic are two different things. Many things are deterministic, but are dynamic and not steady-state.
Also, even in a deterministic universe, you will be able to predict the future only if you have the complete information of the present. But in most situations, you have a lot of unknowns. Even before QM, people have dealt with the unknown by introducing probability. That dates back at least to Cardano in the 16th century. Boltzmann’s work on statistical mechanics was before QM. Also, you shouldn’t forget that one of the three great discoveries that Einstein made in 1905 was about Brownian motion.
In many disciplines, scientists have always been interested in dynamic systems. (Think about evolution, for instance). And it is rare that you have enough information to have a deterministic picture. In that sense, classical physics might have been an exception.
Question (3) Should we say that no changes or discoveries in science are ever PROPERLY culturally significant, but have only scientific significance? If they do seem to have a cultural effect, is that always only by being popularly misunderstood or hijacked by sloppy thinkers? (Think of the profoundly darkening effect of entropy and the heat death of the universe on the later nineteenth century, for example.)
My response to Question (3):
I think you need a distinction between when the cultural impact of science is direct or only metaphorical. For example, the knowledge that we have an ability to make weapons with enormous power of destruction, or the knowledge that our economic activities result in global warming should have direct impact on the way we think about our society and policy decisions. On the other hand, the influence of QM on the way we think about social phenomena are only metaphorical. To quote David Lindley from Uncertainty, “We already know that people act awkwardly in front of cameras, that they don’t tell their stories to a newspaper reporter the same way they would tell them to a friend.” We don’t need to refer to QM to explain such things.
I don’t think it is necessarily bad that people in non-scientific disciplines get inspirations from scientific discoveries. But you should be always aware how strong or weak the connection is and be clear about it when you make a statement. I think the problem is when they make stronger and more general claims than warranted.
Question 4) When we go to the scientists to tell us what interpretations we should NOT make, to avoid the trap of misinterpretations on the part of non-specialists, what do we do when the top physicists do not agree?
My response to Question (4):
Are you talking about interpretations of physical phenomena themselves, or their implications to philosophy and other non-scientific disciplines?
If it is about physical phenomena themselves, it is best to leave it to the specialists.
If it is about implications to non-scientific disciplines, you might have as much right to claim as scientists, but you should get the science part right and should be aware of the things I mentioned in my response to Question (3).
June 25, 2007 at 6:10 am
“On the other hand, it almost seems that the success of molecular biology owes a lot to the arrogant confidence of physicists who believed that they can understand life by applying their approach.”
I’m pretty sure that almost every physicist knows, deep down in his heart of hearts, that 1) chemistry is a branch of physics, and 2) biology is a branch of chemistry, which, in turn, makes it a branch of physics. Physics is the foundation from which which all other physical sciences arise.
June 25, 2007 at 8:58 am
Okay, I am lying prostrate in the dust. But I will rise again. There are anamalies that haven’t been addressed (at least as yet) in what y’all are saying, and we need the rest of what you have to say about QM.
Give me some time to gather my thoughts. Meanwhile, I’m publishing the next installment of “Wily Socrates,” because it is ready to go.
Oh — about the physics-chemistry-biology high-rise that Rock reaffirms and with which I have no quarrel (that was my understanding too), it is very important (from a theory viewpoint) that we still have to study chemical and biological organizations on their own level even when we “know” that they reduce to physics. This is the only way that non-scientific fileds such as the arts and sciences can be credited as rigorous.
Many scientists (not y’all) seem to think that these fields deal with “mere experience” or “subjective” impressions as opposed to the “objective truth and universality” of science. (In semiotic theory, in human meaning-systems, things take their identity from what they are contrasted against!)
Here’s David Lindley’s Uncertainty:
“What fascinates, evidently, is the semblance of a connection, and underlying commonality, between scientific and other forms of knowledge. we return, in this roundabout way, to D. H. Lawrence’s jibe about relativity and quantum theory– that he liked them precisely because they apparently blunted the hard edge of scientific objectivity and truth. We don’t have to be as intellectually philistine as Lawrence to see the attraction here. Perhaps the scientific way of knowing, in the post-Heisenberg world, is not as forbidding as it once seemed.”
To which I reply, “Ya think????”
June 25, 2007 at 9:09 am
Could you go over and look at this summary of Bronowski’s episode “Knowledge or Certainty”?
http://www.wsu.edu/~brians/hum_303/bronowski.html
It’s better to read the whole chapter in the book, The Ascent of Man,” or watch the beautiful episode in the television series.
Please pay especial attention to the point that Browoski believed in the objective knowledge and validity of physics. (He was a physicist who left physics for biology after the disillusionment of the atomic bomb’s use TWICE on Japan, instead of the demonstration of its use his own mentor and others recommended to the president. )
He wants to call QM’s uncertainty principle the principle of tolerance (in the engineering sense) and he has a detailed understanding of QM. Can you see why he welcomes a certain shift in physics paradigms?
June 25, 2007 at 9:42 am
While I think that relativity to some extent and to a lot bigger extent quantum physics were paradigm shifts, the notion in the link Janet provided predares this shifts. For centuries scientists have understood that knowledge is not complete or absolute. If ti were, you stop doing science as knowledge is complete.
June 25, 2007 at 10:03 am
Well, I’m sure Rick made the comment with tongue in cheek, but that’s something I as a biologist, and a condensed matter physicist like Phil Anderson take an issue with.
Quoting from Phil Anderson’s essay titled “More Is Different”:
“But this hierarchy does not imply that science X is “just applied Y.” At each stage entirely new laws, concepts, and generalizations are necessary, requiring inspiration and creativity to just as great a degree as in the previous one. Psychology is not applied biology, nor is biology applied chemistry.”
June 25, 2007 at 12:05 pm
Hurray for Phil Anderson! To my mind, he is saying exactly what I was trying to say above in my comment at 8:58 this a.m. Hurray, it’s happened, and Hi and I AGREE!!!
David says: “For centuries scientists have understood that knowledge is not complete or absolute. If it were, you stop doing science as knowledge is complete.”
David, and everyone else, look at this sentence of David’s because it is crucial. Does it mean scientists have understood that “knowledge is not complete or absolute” or that “it is not complete and absolute AS YET!?”
In other words, what does “knowledge” mean? Does “knowledge” mean that which ends by being absolute and universal “fact,” so there are no loose ends and everything is explained and our representations of reality are PERFECT fits with reality? Because I contend that this is the concept of fact that arose in the 17th-19th centuries in the West and made us so blind and arrogant and led to the non-scientific disciplines being viewed as subjective and arbitrary because they were not able to arrive at scientific fact in this sense, even though science in fact wasn’t (yet) able to either, and still isn’t…
I know that SOME scientists today believe that physics will arrive at “a complete description of fundamental physical reality” but many others doubt this very much. See the “fundamentalist” position as opposed to the “secular” and the “mystical” positions outlined in the essay by physicists on mind, math, and matter (which I’ll look up and give the link again in a second).
But believe me folks, I could even live with that — a complete and final description FOR PHYSICAL (i.e. physics) REALITY if only it were not implied that this means ALL OF REALITY. But clearly, for many scientists and for the scientistic science bloggers on many sites, it does mean precisely this. It leaves no room for any “reality” on other levels of structure and other realms of human life, so Hi’s comments are very very important.
Everything I say, you see, is in reaction against the inflated claims that “science knows everything and what it doesn’t know isn’t real.” Just read the science blogs for this! And you may say that scientists always knew their knowledge wasn’t complete, but did they not think it was “absolute”? Think of La Place. Think of Newton’s Principia. Think of the scientific rationalists who told me animals couldn’t think or feel and neither could babies because they are just machines. It’s the absolutism that enters in here (and that gets carried over into the common mind) that strikes many of us as so illiberal and dangerous.
If we can be more precise about what science knows and how “absolute” its knowledge is or isn’t, we might be able to introduce the color “gray” into some of these black-and-white minds that are running around here. It is not merely some religious people who are fundamentalists in the sense of an absolutely closed worldview with no openness to genuinely Other ways of knowing. The critique of Modernity has been carefully qualifying and mapping out any limits it can find to militate against that absolutism.
It is not the scientific “theories” themselves that scare me but the way many people HOLD those findings, as an absolute authority that should ride rough-shod over every field and over human beings’ deepest values and traditions and overrule any other kind of thought or discovery. This is why non-religious people are coming into the discussion of Dawkins’ The God Delusion, for instance, to point out Dawkins’ scientistic fundamentalism and to defend other ways of knowing (ways that leave Dawkins bewildered by his own admission — why would anyone want to know about that, he says). Dawkins wants to use a very narrow and very hard-edged and reductive and uninformed scientific rationalism to do away with some of the most precious intellectual and esthetic possessions of many people, including many very thoughtful and brilliant people.
There are huge political and social pressures operating here, so that I know that in their guts many scientists want to sympathize and agree with Dawkins in branding religious belief as the root of all evil, but shouldn’t we nonetheless insist on careful discriminations here and not letting any field or any authority become an absolute authhority, including science? Again, to me it is not science or religion which is the problem, but holding either without knowledge and respect for 9at least the possibility of) other ways of knowing in their own proper spheres.
This is why I think what Jacob Bronowski tries to say is so important. And the role of the observer in Relativity and the role of measurement in QM. Because prior to that, it was too easy for Westerners to think that the laws and formulas equalled reality, or were a perfect one-to-one fit. We forgot that our efforts to come to know were involved at all. The mediators of the theory drop out of sight too easily.
It’s much more likely to me that all rigorous descriptions (in all fields) fail to get in all the reality even of their own little aspect of reality. But what I just said is a “belief.” And so is the “belief” that science will arrive at a complete description of physical reality, and that this would be a complete description of everything real and that is would not be modified by anything, even advances in unrelated fields. This are belief-structures. These philosophical commitments are not scientifically verified truths of any kind. Science student need to be drilled and drilled in what science is and at what point our informed belief-structures come into the picture! For every one comment pointing this out, there are 50-100 comments reflecting scientistic belief-structures on the science blogs.
In the same way theists need to be standing up everywhere across the globe and saying “No!” to religious extremism of every kind. No, this is not our faith. This makes our faith into a closed and sealed-off and uncritical (and unloving and unspiritual) authoritariansim that is at odds with everything our fiath stands for. (Okay, I’ll stop preaching for now.)
June 25, 2007 at 12:27 pm
I could mean as yet. But whether it will always be incomplete or not it’s impossible. Also if one were to think it is complete, there is no way to know. So whether one believes there could be a point where it can be complete, I do not find too relevant. It’s impossible to know.
Even if something fits everything perfectly now, that does not imply we will not explore a regime where it does not fit ever. We should exptrapolate, and be dubious of experiments that don’t fit if everything fits so well. But if evidence accumulates then we move to new things.
I just don’t think there is a way to know if we have complete knowledge, so supposing so
it’s never a conclusion, it’s faith. There is nothing wrong with having faith as long as you
make it clear that that’s the case and as long as you don’t let it come in the way of accepting evidence
June 25, 2007 at 1:47 pm
Laplace could have very well been an arrogant man, but, to be fair, what he said was a natural consequence of Newtonian physics. And Newtonian physics is just a theory trying to describe the nature. The theory itself is not arrogant.
What I’ve been troubled is this value judgement. It seem to me that the critique of modernity is as absolutist as what it tries to critique. It necessarily take a black and white view, because it is not a matter of how accurate the theory is, but it is the matter of whether the theory is associated with a good or bad attitude.
For instance, when you wrote that you could not stand Chomskyan because it’s too Cartesian, you don’t care whether it is a useful theory in linguistics or not. It had to be rejected because it is Cartesian.
June 25, 2007 at 3:42 pm
Hi, I do care that Chomskian linguistics is a useful theory! I don’t think any group of rigorous thinkers has ever gotten behind an effort in a discipline without it being u