Saturday, March 16, 2013

The Philosophie of Gaps

“And then there's the joke in which a young man told his mother he would become a Doctor of Philosophy and she said, “Wonderful! But what kind of disease is philosophy?”
~Steven Pinker in “The Blank Slate”

Philosophers and physicists, especially those working on fundamental questions of nature, have a difficult relationship. I know a lot of physicists who use the word philosophy as an insult, and even those who have sympathy for the quest of the philosopher tend to give them a hard time.

And understandably so. I’ve heard talks by philosophers about the “issue” of infinities in quantum field theory who had never heard of effective field theory. I’ve heard philosophers speaking about Einstein’s “hole argument” who didn’t know what a manifold is, and I’ve heard philosophers talking about laws of nature who didn’t know what a Hamiltonian evolution is.

But on the other hand, I’ve met remarkably sharp philosophers with the ability to strip away excess baggage that physicists like to decorate their theories with, and go straight to the heart of the problem. No wonder the relation between both sides can be uncomfortable.

This has left me wondering what is the role of philosophy in physics, or in modern science more general.

I will admit that I have a limited attention span for philosophical arguments. To begin with, philosophers (as apparently everybody in the humanities) have the annoying tendency to throw around names rather than proper definitions. The introduction of a cosmology paper in philosophy style would not contain the Friedmann equations, but instead two conflated paragraphs on the Friedmannian paradigm and its contextual appropriation of the cosmological principle, subsequently adapted as the concordance model.

Leaving aside the name-throwing and over-abundance of multi-syllable words, the issue of lacking definitions is a deep one for me. If somebody can’t write down a definition for expressions they are referring to, I lose interest. Because then their whole argument is in the end just empty words. I am interested in verbal arguments only to the point that they precede the construction of a mathematical model.

Having said that, here is where philosophy plays a role in physics: To develop these verbal arguments that have not yet been possible to cast in a more stringent form. This means though that when science progresses, when our knowledge expands, the room where philosophy is useful inevitably shrinks. The role of the observer in quantum mechanics, horizons in general relativity, or infinities in quantum field theory might once have been philosophical question. They no longer are. Presently popular topics for philosophers in physics seem to be the nature of time and the multiverse. Personally I think these are already topics that are close enough to existing theories that they can and should be cast into a mathematical language. Topics that are further off presently existing theories, and still more clearly playground for philosophers, are for example free will or the role of mathematics in science in general.

This tension between philosophers and scientists doesn’t only exist in physics. Another area where you find frequent displays of this confrontation is neuroscience. Consciousness used to be the field of the philosophers, but no longer so. Yet, philosophers are slow to get off the turf.

A recent display of this can be found in a NYT opinion piece that discusses “famous thought experiments” by philosophers. One of these famous arguments that philosophers discuss to make a living seems to be based on confusing the brain perceiving the color red as a result of photons of a certain wavelength hitting the retina, with the brain knowing about the process of perceiving the color. You might be forgiven for confusing knowledge about perception with the perception itself if you didn’t know anything about the brain, but in the last decade we have learned a lot about how the brain is wired and processes input. Or at least some of us have.

It seems clear to me that consciousness and self-awareness are areas that philosophers will have to clear in the soon future. That is correct: I don’t think there’s anything particularly mysterious about self-awareness, and nothing about it that we won’t be able to understand with some more research on complex systems and neural networks.

But what about science at large? Does this mean that we have a philosophy of the gaps much like we have a god of the gaps, filling in the spaces where currently knowledge is missing, but inevitably on the retreat?

For most of science this is a thorny question (previously discussed here), that being whether or not there is an end to the knowledge about nature that mankind can gather. It’s a question I don’t know how to answer.

But regardless of the answer to this question, for as long as there will be conscious beings thinking they will always be left with the question whether there are limits to what they can think of. And a more pragmatic, though related, question is how science works and how it progresses. These I believe are areas where philosophy will always play a role: to analyze the process of thought and inquiry, and its realization in the scientific endeavor. And as long as we have fundamental questions  about nature, it is good to keep philosophers around to catalyze the process of making soft science into hard science. Even if they are sometimes a little annoying.

43 comments:

WNelson said...

Great post! Particularly about the "perceiving red" class of arguments. I've heard so many "philosophers consciousness" going about this nonsense...and I agree with you, self-awareness probably won't be anything that deep. In fact I don't think intelligent thought altogether will be found to be a particularly deep or interesting process. The stored knowledge is very complex, but the machinery that makes inferences and so on probably isn't.

Physicalist said...

Hi Bee.

You raise some good points, and the relationship between physics (and other areas of science) and philosophy is interesting and difficult.

I thought I'd offer a perspective from the other side (i.e., that of a philosopher of physics).

I too would be frustrated with anyone who discussed infinities in QFT without understanding renormalization and effective theories, or who addressed the hole argument without knowing what a manifold is. And I am sometimes frustrated, but only rarely. In my experience, most of the philosophers addressing these topics have a pretty good grasp of the relevant technical issues. (And some of us are trying to explain the relevance of these issues to the general philosophers.)

More to the point, I see the appeal of pursuing mathematical models to explain how things work; I'm impressed by it too. But it seems clear that understanding requires more than simply having accurate models; we have questions (about interpretation, about metaphysics, about epistemology) that cannot be resolved simply by having in hand a experimentally confirmed model.

People are always going to be doing philosophy. The question is whether their philosophizing is going to be well informed. And while you are (rightly) frustrated by philosophers who are not informed about the relevant science, we philosophers are often frustrated by scientists who address philosophical questions without being informed about the relevant philosophy.

Scientists pontificating about free will without understanding debates over compatibilism are an obvious example of this. Another (perhaps closer to home) is physicists like Susskind who appeal to verificationist principles to try to paper over inconsistencies in their accounts of Black Hole Complementarity.

Also, I'm not sure that it's helpful to suppose that once scientists get some tools to examine a particular field that philosophers are supposed to "get off the turf." No matter what the data show, it is going to be a philosophical project to decide whether the old philosophical worries have been resolved, and I have yet to see a scientific answer to a question that didn't raise new and interesting philosophical questions. I'm inclined to think that philosophy is "philosophy of the gaps" only to the extent that science is also always "science of the gaps." We always trying to figure out what we don't understand.

I think it's legitimate to ask about the "role of philosophy in physics," but you should recognize the possibility that philosophers might properly be indifferent to the question of whether their work helps scientists construct or test models.

I personally moved from physics to philosophy because when I was studying quantum mechanics I was told that I wasn't allowed to ask questions about the ontology of quantum mechanics. ("Shut up and calculate.") Philosophers were addressing the questions that I cared most about; physicists weren't.

I'm not sure what you're referring to when you suggest that the role of the observer in QM has moved from being a philosophical question to being a scientific one. (Perhaps you've discussed it in a post I've missed.) If the measurement problem has been resolved, I'll be very pleased to update my syllabus.

(Just as an aside: I don't think your gloss on the Mary and Zombie thought experiments discussed by Gutting captures what's going on in these arguments. I agree that the arguments fail to establish dualism, but I probably shouldn't make this longer by explaining why.)

Thanks for the thought-provoking post.

P.

Arun said...

I don’t think there’s anything particularly mysterious about self-awareness.

Do we understand then, in principle, how to make a self-aware machine?

nogre said...

With my philosopher's hat on (which I sleep in) I am always bemused when people think philosophy is somehow disappearing. Philosophy is big, with philosophy of physics and science only being one part, and it is ever growing.

I don't want to apologize for bad philosophy. There's lots of crappy philosophy. But good philosophy often turns into common sense. From that perspective it can look as if good philosophy is disappearing. What was once considered cutting edge philosophy is now just accepted fact. The bad philosophy remains bad. So it looks like we are left with facts and bad philosophy.

As for physics, the more discoveries physicists make only tend to compound philosophical problems, not lessen them. Using Hamiltonian Evolution doesn't solve any philosophical problems I have ever heard of, though it does mean that our philosophy of physics now has to be able to explain how Hamiltonian Evolution compares with other physical theories.

In the end, posts like this means philosophy has done its job. The more that things just seem to make sense and there is (apparently) less work for the philosopher to do, just means that the hard work of the last generation of philosophers is now paying dividends. But time marches on and the problems will pile up again.

nick herbert said...

Scientific problems involving consciousness are not merely the concern of philosophers and physicists but also--as in the Middle Ages--the province of the Powers That Be. As with Galileo and the Inquisition, several areas of inquiry still exist that are OFF LIMITS to scientists. See for instance FORBIDDEN KNOWLEDGE at http://quantumtantra.blogspot.com/2008/06/forbidden-knowledge.html. Pursuing certain scientific questions, even in the 21th Century, can land you behind bars for a long time.

DocG said...

I'm pleased to see that there are philosophers reading here, and that they are speaking up in defense of their art. I'm neither a philosopher (not professionally anyhow) nor a physicist, but I can't resist chiming in with some thoughts of my own.

First of all, I think it important to make the point that it is philosophy that concerns itself with what is true and NOT science. Science was never about establishing some absolute truth, but about exploring, and testing, various possibilities. Which is why it has now become the custom to express scientific findings in statistical, rather than absolute, terms.

More fundamentally, it is philosophy that determines the basic conditions under which science may be said to operate rationally, or, if you prefer, meaningfully. It's not surprising that scientists squirm under the thumb of the philosophers because it's natural to assume they would prefer to be free of all constraints. And in fact this is what we see all too often in physics, scientists making essentially philosophical statements in the guise of scientific statements.

I'll provide an example in my next post.

DocG said...

Fundamental to all science are certain basic principles -- philosophical principles -- that are in themselves not subject to scientific testing. Prominent among them is the so-called "subject-object dichotomy." All scientific observation is based on the ability to clearly distinguish between an observer (subject) and that which is being observed (object). And no, I'm not about to discuss the measurement problem, so lower your pistol, Bee.

Or, on the other hand, maybe you better pick it up again, because I'm going to use this principle to contest what you just wrote a moment ago, specifically: "I don’t think there’s anything particularly mysterious about self-awareness, and nothing about it that we won’t be able to understand with some more research on complex systems and neural networks."

I presume you're referring to the now well known assertion among many cognitive scientists, and others of that ilk, that the mind is some sort of epiphenomenon of the brain, meaning that the age old "mind/body" duality cannot be maintained. And though you didn't actually come out and say it, the implication is that even our precious sense of self-awareness itself is not immune to the probings of scientific research.

In short, if the mind itself can be shown, scientifically, to be a product of purely physical brain activity, then all philosophers can safely be dismissed, leaving the scientists free to reign supreme.

What is usually overlooked in all the many disputes over such claims (which tend, mistakenly, to focus on the "obvious" nature of self-awareness) is the embarrassing fact that "the mind," or whatever you might prefer to call it, is not only something required by metaphysics, but also something required by science itself.

Because with no clear separation between a mind and a brain, there is no longer any subject to independently observe the object known as the brain, and without such an observer there is no such thing as a science of the brain -- or anything else for that matter.

This tells us that the question of how the mind relates to the brain is, in principle, a philosophical and NOT a scientific issue. And any "science" that pretends to have "proven" otherwise is self-defeating, i.e., delusional.

WNelson said...

DocG, I would guess most scientists would take the above example as showing essentially why subject-object dichotomy is *not* an essential precept of science. Of course the proof is in the pudding, and brain science isn't far enough advanced yet to fully settle these doubts.

Physicalist said...

DocG:

I agree that one can't avoid philosophical issues when confronting the mind-body problem (or pretty much any other problem, for that matter).

We need to decide what it means to say that something is physical, what we are talking about we use the word "mind", whether we can make sense of (or have evidence for) properties that have no physical effect, etc. And these questions can't be resolved with experimental data.

But, having resolved these issues, we can in fact have very good evidence for the claim that the mind is physical.

As you no doubt have guessed from my pseudonym, I think that we have such evidence (supplied primarily by 20th century physics, I argue). And a healthy majority of philosophers join me in accepting physicalism.

Best, P.

Giotis said...

Of course Philosophy is a vast subject with philosophy of science just being a part of it.
But even there its role is quite clear for me. Philosophy is human’s struggle to come to terms with the (physical) world because everything, even the physical world, must come to terms with the human mind. In that respect it can’t be obsolete. Denying the role of philosophy in science is like spitting in the face of humanity, substituting the thinking man by the naive technician which collects and categorizes data fitting them into models…
Deep down such an attitude is misanthropic. Human is the source of all things and (If I may use this term in such way) everything must be humanized. Extending it a bit I should say we humans are our own Gods, nothing is important or has a meaning if we don’t say so, not even physical reality and everything is void of meaning whithout us. Philosophy is just that in my view, it is the overseeing human eye standing above everything else.
Man is the measure of all things the ancients used to say and they were right.

Jeminah Jones said...

Yes, but what does all mean?

DocG said...

I would add that just as we can't have a brain without a mind to observe it, we can't have a mind without a brain to produce it.

Remind you of anything?

Sounds to me as though the two are: complementary!!!! Unless of course there is some "hidden variable" we are not yet aware of?

(Nice smile, Jeminah.)

Plato Hagel said...

Sean Carroll of Cosmic Variance, California Institute of Technology and David Albert-Columbia University
Science Saturday: Time’s Arrow

How a philosopher of science spends his time (08:34)

Best,

Uncle Al said...

Philosophy conceptualizes before math, theory squeezes out goo and dribble, observation tells theory what to predict. Quantum gravitation, SUSY, and dark matter have no empirical validation. Projection of an ellipsoidal surface upon a Euclidean plane without distortion, folds, or cuts is the Shroud of Turin, reproduced given a kitchen oven. Where were the geometers?

Racemic D_3-trishomocubanone is vacuum supersonic expanded into a chirped pulse FT microwave spectrometer. Is there observed only one deep cryogenic rotation spectrum, or a second at higher temperature? Nobody knows if the vacuum is isotropic or trace chiral (parity violations, symmetry breakings) toward enantiomorphic fermionic matter distributions. Jupiter had moons and the One True Church’s inerrancy was wrong, Yang’d and Lee’d on its own front porch. Talk is not enough. Ya gotta look.

Phil Warnell said...

Hi Bee,

I can’t help but wonder if the continuing maelstrom which now swirls around what many have dubbed the “Kerfuffle” now focused around Lawrence Krauss and David Albert inspired this post. I wonder this as I think it equally fair to criticize scientists when they venture into the realm of philosophy with having little knowledge or experience regarding the subject.

However what I find as most disappointing is when some think their science is somehow bettered if completely left devoid of philosophy, as convinced somehow that philosophy stands as being some crude precursor to science, when it’s actually science that represents being just one of the many tools it’s been able to create and develop to continue and expand its pursuit. However I don’t hold scientists to blame for this, yet rather more the philosophers themselves, as they often forgetting that philosophy’s practically meaningful mission should be and always remain as being simply to serve to increase general human understanding rather than itself.


“The withdrawal of philosophy into a "professional" shell of its own has had disastrous consequences. The younger generation of physicists, the Feynmans, the Schwingers, etc., may be very bright; they may be more intelligent than their predecessors, than Bohr, Einstein, Schrödinger, Boltzmann, Mach and so on. But they are uncivilized savages, they lack in philosophical depth – and this is the fault of the very same idea of professionalism which you are now defending.”

-Paul Karl Feyerabend, “For and Against Method” p-385


Best,

Phil

Zephir said...

/* I am interested in verbal arguments only to the point that they precede the construction of a mathematical model. */

In hyperdimensional reality the mathematical models based on analytical approach are poorly conditioned and they're predestined to failure (note the huge landscapes of stringy and loopy theories). From this reason I would prefer the fuzzy logics and numerical models (multiparticle models in particular) for deterministic description of such hyper-dimensional connections.

In AWT we are living in random Universe, which we are sampling for gradients. So that the people, deterministically thinking scientists in particular tend to follow and extrapolate rather the existing gradients of positive curvature, i.e. from few well confirmed facts, which are already supported theoretically. Some physical journals even don't accept any experimental work, which is not supported "theoretically" (despite such a theory isn't often nothing more, than just less or more complex functional regression of experimental data).

From this reasons I'm focusing to exceptions (casual gradients of negative curvature) and I tend to interpolate new predictions from large number of existing empirical facts in emergent way.

Did you note, that large physicists like Feynman or Einstein actually talked about philosophy of the science all the time at public, despite they refused the vague philosophy proclamatively?

Zephir said...

Dense aether model compares the observable universe to the portion of water surface observed with its own transverse waves. At proximity the observable reality appears complex and turbulent in similar way, like spreading of ripples at short scales. With increasing distance the character of these ripples becomes more regular and the waves are spreading in circles. Because such a waves don't interact with underwater very much, the deterministic approach of general relativity can be applied to it without problem. This is just the analogy of the recent era of physics, when the deterministic approach did prove its usefulness: the more deterministic model we used, the more predictions we get about observable reality.

Unfortunately, when the distance of observation increases even more, then the deterministic character of observable reality vanishes again. Whereas atoms and medium sized stars mostly composed of atoms are pretty regular spherical bodies, the even smaller or larger objects observable become increasingly irregular. From this moment the low-dimensional formal models not only don't help the description of this hyperdimensional reality better - they actually make this description worse. I'm not quite sure, whether the formally thinking physicists realized this paradigm shift, which some philosophers realized already:

Max Tegmark, a MIT teacher: The Mathematical Universe

versus

Alan P. Lightman, a MIT teacher: We are living in a universe uncalculable by science.

Plato Hagel said...

So I would think that setting oneself up for the "right questions" serves to help others also wonder about such foundations ad how to approach?

Not that you need "to be older to have settled for something less." what is desired then by a theoretical physicist who might ask, "am I asking the right question?" What's wrong with that?

I do not think that it is a terrible thing to think about, as one ventures into the models of assumption so as to direct their attention toward a leading model understanding in science, lead by science.

This may be an attempt then, to clear the air so to speak about one's declaration of position in science?

So okay, what value then not seen when understood as to clarify their position? Logically and consistently. Is that such a bad thing?

Language, has to mathematically be reduce too, while mathematics has to clearly be defined in a language we understand? This is an inductive/deductive relationship with the world that each has to ask of them self, that while being reduced too, what is self evident becomes realistically, the next question on the road toward discovery?

What you then show in your science is always the next question whether you stand in front of a board to show your colleagues, what you have derived as to say what do you see wrong is no less the dialogue that goes on in self?

A discovery about truth? You do not develop the LHC with out leaving room for scientific validation as to reveal the gap in the knowledge, is now affirmed and confirmed. You are now on more of a solid foundation so as to say what comes next. What will develop from here on in new perspectives about physics beyond the standard model.

Best,

Plato Hagel said...

http://physicalworld.org/restless_universe/figs/fig_1_2lrg.gif

These are not distractions from trying to understand physics, but are the tools needed to make that understanding possible. It is only through using mathematics that a secure understanding can be achieved. When you see an equation, welcome its concision and clarity and try to ‘read’ the equation just as you would the large number of words it replaces. Learn to get beneath the squiggles and the equals sign and to understand the quantitative assertion that is being made.The lawful Universe

Predictable comments about the future is the realization that such math will help form an understanding of what is being described in nature. Help bring us closer to what nature is saying.

The value of non-Euclidean geometry lies in its ability to liberate us from preconceived ideas in preparation for the time when exploration of physical laws might demand some geometry other than the Euclidean. Bernhard Riemann

Plato Hagel said...

Tabula rasa (Latin: scraped tablet or clean slate) refers to the epistemological thesis that individual human beings are born with no innate or built-in mental content, in a word, "blank", and that their entire resource of knowledge is built up gradually from their experiences and sensory perceptions of the outside world.

Arun said...

Effective field theory may have banished philosophers, but still has a problem of mass scales, which the non discovery of SUSY at LHC only exacerbates.

Arun said...

Re:mind-body dichotomy: per some ancient Indian thought, the mind - the thing that produces the running commentary in your head, the stream of thoughts.- is just as physical as your brain. So is any higher reasoning power. Their way around the subject-object dichotomy I think is to say that the basis of all existence is an undifferentiated awareness. Of course, I may not understand what they were saying. But what is beyond dispute is that to them, mind (minus awareness) is physical.

Rastus Odinga Odinga said...

Dear Bee, you are making a big mistake, one which I understand because I have made it myself.

Physicists do philosophy all the time, and they almost always make a hash of it. Consider the following example: "The basic idea of GR is the equivalence principle". I used to believe this, and got into an argument about it with a philosopher. It took me a long time to accept this, but the fact is: I was annihilated in that argument. GR is the statement that spacetime is curved, and that what we used to call gravitation is a mistake arising from our ignorance of that curvature. Where is the equivalence principle in this? Answer: it is nowhere. It is just philosophical gas of a kind that no well-informed contemporary philosopher would expel.

And it makes a real difference: look at all the excitement over the "violation of the equivalence principle" in the current firewall discussions. Physicists are making actual mistakes in their *physics* as a result of doing bad philosophy.

For sure, there are incompetent philosophers who talk nonsense about physics. But they are totally harmless: the real harm is done by physicists doing bad philosophy [particularly when they don't know that they are doing philosophy....]

Peter Shor said...

Re: Rastus

The fact that there are philosophers who don't believe the basic idea of GR is the equivalence principle greatly reduces my opinion of philosophers. One of the basic principles of physics is symmetry, and the equivalence principle is the symmetry behind the derivation of GR. If the philosopher denies that the equivalence principle has anything to do with GR, he is making a complete hash of the physics.

The reason you lost the argument is that philosophers tend to be better debaters than physicists.

DocG said...

What I find particularly interesting is so much of the excited speculation regarding "the multiverse" and similar constructs. Brian Greene is especially amusing in this respect, since his ideas remind me so much of Carl Sagan, with his talk of "billions and billions" of stars (or galaxies) while his eyes are literally popping out of his head.

Translate that into "billions and billions" of universes and it sounds like essentially the same sort of thing. Only of course, Sagan's claim can in fact be verified, while Greene's cannot. And in all likelihood can never be -- in principle.

What I'm reminded of is the old argument among philosophers concerning all those angels dancing on the head of a pin. And in fact what Greene is doing is not physics at all, since such theories (and here I include also the Anthropic Principle) can, by their very nature, never be tested, but are in fact nothing other than philosophical speculation.

And speculation of an extremely weak sort, since there are no insights involved, only a rather desperate sounding attempt to get around certain problems that the currently fashionable theories are unable to deal with. If you can't really explain something, then apparently you can explain it away by proposing fantastic "theories" that have the great advantage of being unfalsifiable.

DocG said...

Arun: "Their way around the subject-object dichotomy I think is to say that the basis of all existence is an undifferentiated awareness. Of course, I may not understand what they were saying. But what is beyond dispute is that to them, mind (minus awareness) is physical."

Sounds to me more like the other way around, that the mind, as "undifferentiated awareness" is fundamentally non physical, since awareness is non-physical. It's the old argument between idealism and materialism, seems to me. And as I see it, there is simply no way around it, for every argument on one side there is a counter argument, ad infinitum.

This reminds me a LOT of what Bohr had to say regarding "complementarity." And if you've read much of his writings, you'll know that he did not limit this idea to quantum physics only.

As far as I can tell, Bohr was the only major physicist who was also a major philosopher, and it was his mastery of both spheres that enabled him to come up with something truly revolutionary, in both the realm of physics and of thought generally.

In fact, as far as I can tell, Bohr already anticipated many of the "aporia" identified by Derrida and some of his fellow post structuralists. It is these aporia that imo lie at the heart of a great many dilemmas, both philosophical and scientific, to the point that we can consider them axiomatic.

Which means that in principle, there can never be a unified "theory of everything," but only a fundamentally split theory, split in roughly the same manner that quantum physics is split between two irreconcilable alternatives.

This is, of course, no longer science, but it IS philosophy and so as far as I am concerned, no scientist of today can afford to ignore these very basic philosophical issues.

Zephir said...

Aldous Huxley: about consistency

Rastus Odinga Odinga said...

Peter Shor said:

"One of the basic principles of physics is symmetry, and the equivalence principle is the symmetry behind the derivation of GR."

This is standard physicist mumbo-jumbo. When you try to analyse any of these assertions, they just dissolve into verbiage. Our hostess here very justly said: "If somebody can’t write down a definition for expressions they are referring to, I lose interest."

My advice: look to the mathematics. I know what a curvature tensor is. I do not know what a "symmetry principle" is, and I cannot put my finger on the part of the mathematics that might correspond to it. All this talk of "symmetry" [except when it *can* be well-defined, in terms of isometries] is just the ghost in the machine.

Another thing one learns from philosophers is precision. To say, "the equivalence principle is the symmetry...." is like saying that apples are equivariant. Well, physicists imagine that there is something solid deep inside this confused verbiage. I ask you to consider the possibility that there isn't.

Again: spacetime is curved, and that fact is responsible for the mistaken notion of "gravitational force". This is GR, and if you want I can readily turn these words into mathematics. Why do we need the "equivalence principle"? It's superfluous and, I stress again, this kind of confusion leads to *real* confusion in the physics. Look at all the nonsense about bimetric theories and massive gravity on the arxiv...

"The reason you lost the argument is that philosophers tend to be better debaters than physicists.."

No, the reason I lost is because I was wrong. It was painful to accept this but ultimately liberating....

Leon said...

Does philosophy fill the gaps in mathematical physics with words, or does physics fill the gaps in natural philosophy with mathematics?

Michael Gogins said...

The essential problem in the relationship between physics and philosophy is that physics, as with science in general, presupposes certain philosophical views: that there is a real world independent of subjective observers, that this world can at least partly be represented by mathematical laws, and that scientists can improve their understanding of those laws by doing experiments (this is the part where the assumption that there is a real world out there comes in, also the assumption that the laws are universal). These presuppositions WARRANT science, they lend their authority TO science. These presuppositions cannot be WARRANTED BY science.

Any problems with the philosophy of fundamental physics, the measurement problem, the problem of consciousness, etc., etc., can I believe be reduced to this problem of presuppositions, which involve both a subject (the scientist with his or her theories and experiments) and an object (the physical world).

I don't see any way for this problem to be resolved, and I certainly don't think it is going to go away anytime soon. Or ever...

I think this is a permanent feature of the human condition, like a tragic sense of life.

Plato Hagel said...
This comment has been removed by the author.
Plato Hagel said...

Leon:Does philosophy fill the gaps in mathematical physics with words, or does physics fill the gaps in natural philosophy with mathematics?

I do not see it this way. The language derived from the equations needs to be exact, so in essence while you write the mathematics(as exacting as it is), you must also develop a new language. You convey that to others you talk to without need then of the math, for if you speak concept readily, then you are at the same time being mathematically exacting?

As you write your equations they are specific and have a whole history in their development. To progress, you need to extend that equation in order to say that the natural process with which it identifies, reveals other things in nature that was not seen before. Higg's spin O

In a predictive sense you set up the experiment in order to answer the question. Validation seeks to ensure the gap is filled.

Experimental validation in terms of Higg's allows the further consideration?

The development of a new collider will be necessary in order to study LHC potential discoveries beyond the present SM. A high-energy muon collider is the only possible circular high energy lepton collider that can be situated with in the cern or fnal sites. However it requires two major developments, the production of a millimole of muons and the phase compression of its beams.Carlo Rubbia: A Millimole of Muons for a Higgs Factory See Also: Muonic Higgs Factory: My Question To Rubbia

Once gap is filled, it sets up for the next question. As a layman, my philosophical situation has been forgiven. :) Thanks.

Best,

Plato Hagel said...

An example of language development is perhaps in order?

Adinkra Symbols(physics)

As a theoretical physicist how complete the process for you to see that mathematically you have indeed gone the full range of it's analytical basis, to have seen it all based in a image?

It provides for a divergence from what has always been in question so as to see the abstract mind has ventured to areas of knowledge that you did not know even existed?

TVO S James Gates on Does Reality have a Genetic Basis

Hopefully Bee this example helps to widen the perspective and scope of the question you raise.

Best,

Peter Shor said...

@Rastus:

I said ""One of the basic principles of physics is symmetry, and the equivalence principle is the symmetry behind the derivation of GR."

Rastus said: "This is standard physicist mumbo-jumbo. When you try to analyse any of these assertions, they just dissolve into verbiage."

Look at it this way. There are two parts to general relativity. (1) Space is curved. (2) Gravitation is inertial. The second part is essentially the equivalence principle.

So the philosopher was right to some degree: the physicists' explanation is rather vague. And the equivalence principle certainly isn't all of GR. But it's a very important piece of it.

John G said...

http://www.tony5m17h.net/IFAEinstein.html

Since Einstein referred to Spinoza as a "religious genius ... distinguished by ... cosmic religious feeling", my comments will come from a Spinoza - Pantheist - Taoist perspective. According to the Stanford Encyclopedia of Philosophy:

"… A defining feature of pantheism is allegedly that God is wholly immanent … pantheism denies the theistic view that God transcends the world …
the most complete attempt at explaining and defending pantheism from a philosophical perspective is Spinoza's Ethic …

philosophical Taoism is one of the best articulated and thoroughly pantheistic positions there is …".

So that I can discuss how such religion fits together with science, here is an outline of how I see science, taken from comments (by NC and B. and Count Iblis and me) on the Cosmic Variance blog:

NC said: "… the idea that genes drive evolution … is stopping off at an arbitrary point in the long chain of causality. The only scientific thing … to do, … searching for ultimate causes, is to not stop at genes but go on a step and tell us about how 'selfish background radiation' drives evolution …".

I said: "... Once background radiation is brought into play, from a pantheistic view, you get to Dave Rothstein's possibility of "God intervening every time a [quantum event] measurement occurs". ...".

B. said: "… Instead of asking where the universe comes from, ask where the natural numbers 'come from'. ... Is maths the foundation for the theory of everything? …".

Count Iblis said: "… That's a good question and that has lead some people to postulate that reality is purely mathematical in nature. … You can define them [the natural numbers] recursively:

0 = {} (empty set)
1 = 0 U {0} = {0}
2 = 1 U {1} = {0,1}
etc. …";
B. said: "… in the end you'll sit in this field of complex numbers, and every one of them is just a point in a plane. Does C have a cause? …".

I said: "... If you want to continue the process, you might note that

C is the real Clifford algebra Cl(0,1;R), and
you can go from there on to real Clifford algebras of arbitrarily high dimension.
Since bivectors give you Lie algebras, you get gauge-group-type things, and
you might think of spinors as fermions, and
think of the vector space as spacetime, and
even try to put such things together to form Lagrangians … and
see where Einstein-type faith might lead. .."....

Jochen said...

I think the core misunderstanding behind the occasional clashes between scientists and philosophers is the idea that both are after the same kinds of knowledge, from where the idea comes that once science has sufficiently established itself within a particular context, philosophers ought to 'clear the turf'.

But I think the notion is a simple category error. Science is, predominantly, about statements of fact, and generally empirical fact, such as, 'the fine-structure constant is roughly 1/137'. This is a statement whose truth can be (given some, usually unstated, philosophical assumptions) empirically validated. If now philosophers were after the same kind of truths, then to expel them from the domain of discourse once science has arrived at statements that are, like the above, precise enough to be subject to such empirical investigation, would be justified.

But I don't think they are. Rather, the knowledge they're after concerns the justification and analysis of statements such as 'the fine structure constant is roughly 1/137'. Consider different possible ways by which you could arrive at such a statement:

1) You guess.
2) You have access to a kind of black box, some machine which you know how to manipulate in a certain way so as to yield empirically verifiable predictions.
3) Using knowledge about the world, you use a deductive procedure applying trusted rules of inference to infer it.

One would not like to attribute to all three methods, and their practitioners, the same amount of knowledge about the world; yet, as far as the merely factual content of the proposition is concerned, they are all equally right. But their positions are not equally justified: the truth of a guess is independent of what actually is the case, and thus, lacks justification. The truth of some oracular black box prediction does not fare much better: what it says may be true, but there's no reason (other than perhaps its track record) to suppose it to be. Thus, only the third case seems to have a shot at constituting genuine knowledge about the world. But in order to find that, we need philosophy: as far as science is concerned, the cases 2 and 3 appear indistinguishable (and arguably, the second case is pretty much what obtains in the case of quantum mechanics).

Philosophical analysis then simply has a different object than scientific investigation; thus the idea that the latter could supplant the former is just based on a misunderstanding.

In any case, I believe that this blog post, and other, similar recent outings, shows the need for greater communication between these particular 'two cultures'; with that, maybe one would have less philosophers saying silly things about physics, and also less physicists with silly ideas about how something can come from nothing, which, I think, would mean that everybody wins...

Andrew said...

I'd like to know why you think there's no fundamental mystery about self-awareness. Here's my speculative try.

Yes, we do know how to make a self-aware machine in principle. We do know how to make a machine that has a model of another system. Now let that system be "itself".

Many models of motor planning by animals have something called "efference copy" which feeds into an "internal model" which is the brain's model of the a part of the animal - a model of itself, so to speak.

Owen Holland and Rod Goodman are trying to build a robot with self-awareness along these lines.

Steve Carlip said...

Rastus Odinga Odinga said

Physicists do philosophy all the time, and they almost always make a hash of it. Consider the following example: "The basic idea of GR is the equivalence principle". I used to believe this, and got into an argument about it with a philosopher. It took me a long time to accept this, but the fact is: I was annihilated in that argument. GR is the statement that spacetime is curved, and that what we used to call gravitation is a mistake arising from our ignorance of that curvature. Where is the equivalence principle in this? Answer: it is nowhere.

You gave up too easily. It's true that the particulars of the curvature of spacetime are necessary to understand the dynamics of GR. But before that's relevant, you have to know that gravity could have a geometrical explanation at all. That is, you have to know that gravity picks out a preferred set of spacetime trajectories, independent of the objects moving along those trajectories, that could be geodesics in some geometry. This is what the principle of equivalence gives you.

Suppose the ratio of gravitational to inertial mass were different for electrons and protons. Then you might still be able to describe the motion of electrons in terms of a curved spacetime, but you'd have to describe the motion of protons in terms of a different curved spacetime. There's a good reason that gravity has a simple geometric explanation while, say, E&M doesn't.

(Kaluza-Klein theories evade this, but they do so by requiring that electrons and protons have different initial velocities, albeit in an extra dimension. In other words, they geometric electromagnetism, but only by working out how to reconcile electromagnetic interactions with the principle of equivalence.)

I'm afraid the philosopher you were arguing with did not understand the physics well enough. That may not have anything to do with whether he or she was a philosopher, of course.

Unknown said...

Coming to this way late, but: DocG, you wrote, "I would add that just as we can't have a brain without a mind to observe it, we can't have a mind without a brain to produce it." Surely the latter clause is begging the question, isn't it? How could we know this? (even assuming you're willing to define "brain" broadly enough to include the inhabitants of Beta Canes Venatici 4, who think with organs located in their chests, not to mention C3PO)

Samyogita said...

Thanks for this great post! :)

Recently found this wonderful quote from Søren Kierkegaard in THE Cognitive Neuroscience book by Gazzaniga, Ivry and Mangun. :

That a man should simply and profoundly say that he cannot understand how consciousness comes into existence— is perfectly natural. But that a man should glue his eye to a microscope and stare and stare and stare— and still not be able to see how it happens— is ridiculous, and it is particularly ridiculous when it is supposed to be serious... If the natural sciences had been developed in Socrates' day as they are now, all the sophists would have been scientists. One would have hung a microscope outside his shop to attract custom, and then would have had a sign painted saying: "Learn and see through a giant microscope how a man thinks (and on reading the advertisement Socrates would have said: 'That is how men who do not think behave')".

tytung said...

You are right that verbal arguments without the relevant mathematical equations are not really progressive in the established areas.
However, on the other hand, one of the point of philosophy is that there is possibly no such thing as "established" knowledge. It is possible that these established theories, however successful, are still illusions that are based on erroneous assumptions.

tytung said...

I would like to take an example, all our physical theories (even Newtonian deterministic theories) requires the assumption of free-will - the freedom of choice in choosing the preparation and measurement apparatus.
So I don't think neuroscience, based on the deterministic mechanisms, can explain (not to mention to refute) free-will. A theory simply cannot refute its assumptions.

Hans Mühlen said...

Actually the foundations of GR are much more interesting than that.

>> Rastus Odinga Odinga: "spacetime is curved, and that fact is responsible for the mistaken notion of "gravitational force". This is GR, and if you want I can readily turn these words into mathematics..."

>> Steve Carlip: "It's true that the particulars of the curvature of spacetime are necessary to understand the dynamics of GR. But before that's relevant, you have to know that gravity could have a geometrical explanation at all..."

There exists a 4D spacetime reformulation of Newtonain mechanics and gravity called Newton-Cartan theory. Just as in GR there is no gravitational force in NC theory, "gravity" is geometrized and free bodies move along the geodesics of a dynamical connection. Even the field equations (basically Poisson's equation) can be written in a form which is eerily similar to the GR field equations.

There are other examples of theories where gravity is an effect of curved geometry and not an interaction, like Nordström's Lorentz-invariant scalar theory, which was geometrized by Einstein and Fokker even before GR was complete.

This shows that geometrization of gravity is in no way sufficient to characterize GR as a theory of gravity (not even to distinguish it from Newtonian gravity), as is mistakenly assumed in an embarassingly large number of places, even textbooks. You must add several other characteristics to get to GR, such as requiring the theory to be relativistic (like Nordström but unlike Newton-Cartan) and requiring background independence (or a ban on absolute objects or prior geometry; unlike both Nordström and Newton-Cartan), plus the exact form of the action.

Newton-Cartan theory has also been a favourite playground for philosophers of science debating the question of "empirical indistinguishability" of theories, which links in with another perpetual debate which is guaranteed never to be resolved, that on "scientific realism": Newtonian gravity and Newton-Cartan have essentially the same empirical content (they predict the same paths for freely falling bodies), but they appeal to completely different ontologies to explain this (one claims there exists a gravitational force in a flat geometry, the ohter claims the geometry is dynamically curved); how can we then justify scientific realism, where we are asked to believe that the ontological claims made by a theory reflect what is in some sense "out there"? This is an example of a philosophical problem where it is unlikely that a further mathematical analysis (as suggested by Sabine) would help resolve the issue.