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Science

Physicists War Over a Unified Theory 451

Posted by michael from the stop-throwing-erasers dept.
beggs writes: "I was looking through the New York Times and came across an article which talks about a new front in the war to find a unified theory, but this one does not come from the particle physicists, it comes from the solid state physicists. Here is a little quote for wet your appetite: 'some solid-state physicists are trying to show that the laws of relativity, long considered part of the very bedrock of the physical world, are not platonic truths that have existed since time began.'"
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Physicists War Over a Unified Theory More

Physicists War Over a Unified Theory

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  • I know nothing about physics. So basically whatever Stephen Hawking says about this, that's my opinion too.

  • natural laws hold true, but values do not (Score:3, Interesting)

    by Anonymous Coward on Tuesday December 04, 2001 @01:31PM (#2654436)
    I find it very amazing that some people think the speed of light and other 'constants' could not have changed in the distant past from a value much different than what we observe today. Trying to measure the age of the universe based on relativity is good, but using a 'constant' like the speed of light to aid in doing so is folly. No one has been around to observe every last possible variation in the 'constant' speed of light.

    So I think it's very good that these scientists are challenging theories like this.

    • Actually, in the theory of realitvity, as far as I understand it, the speed of light is the central constant around which everything is built. It can't change because it determines everything, including the passing of time. If the speed of light became slower, then so would the passing of time of time, with the result that light would still travel the same distance in the same time.

      • Re:natural laws hold true, but values do not (Score:5, Insightful)

        by Anonymous Coward on Tuesday December 04, 2001 @01:58PM (#2654570)
        This isn't quite correct. You are right that in changing the speed of light you are only redefining the time unit. (One second is how long a photon takes to travel a certain distance.) In everyday work, (yes- I am a physicist) I choose units where c is one. It makes things so much easier.

        What the physicists are measuring isn't the speed of light - it is the dimensionless constant alpha. Since alpha is dimensionless, you cannot renormalise changes in it by changing the size of your units. (Alpha is a measure of the strength of the electromagnetic (and electroweak) force.)

        Quantum mechanics is the thing we know least about. We have tested general relativity to fourteen decimal places, but QED (quantum electrodynamics) has only been tested to ten decimal places. Quantum is a theory filled with ad-hoc rules. GR is increadibly simple. It wouldn't surprise me at all if quantum field theory was shown to be a suitable limit of what happens to gravational waves once non-linear effects become important, and once you start running into the effects of compactified dimensions.

        • Re:natural laws hold true, but values do not (Score:4, Funny)

          by gowen ( 141411 ) <gwowen@gmail.com> on Tuesday December 04, 2001 @02:18PM (#2654658) Homepage Journal
          In everyday work, (yes - I am a physicist) I choose units where c is one. It makes things so much easier.

          At my old university, we simply referred to these as "God's Units". Of course, I'm in a maths department now, so we just write c and leave all the fiddling about with actual numbers to the physicists.

        • (One second is how long a photon takes to travel a certain distance.)

          Question: Seconds, as a unit of time, have been around far longer than the ability to observe photons, have they not? Has the concept of a second been redefined by physicists to mean the amount of time it takes a photon to travel a certain distance?

          Not trying to be argumentative here, just curious. My knowledge of physics could fit in a thimble, with room to spare

        • On the other hand, testing the equivalence principle is not the same as testing GR...
        • What??

          OK, first simple correction, actually, changing the speed of light changes the *distance* unit, not the time unit. We define time as cycles of a cesium atom, so the correct definition is that one *meter* is the distance light travels in some fraction of a second, per SI definition.

          QED is the most well tested consistent theory that physics has ever seen. GR is not NEARLY as well tested as QED is. Blandly stating that QED has only been checked to 10 decimal places is crazy - QED is consistent to 10 decimal places with about 12 (if memory serves) completely different experiments. That's far more impressive than any test GR has undergone.

          Alpha is the most well-known physical constant in physics right now, and suggesting that it changes, while it is possible, would not be in the least bit consistent with astrophysical findings. QED is more than consistent over well over several decades of orders of magnitude. GR doesn't win there at all.

          QED is very simple, with absolutely *no* ad-hoc rules. The ad-hoc rules only come into play when

          a) a physicist asks a meaningless question (What is the sound of one electron clapping?)

          b) other forces come into play. You're talking about QED - that is, quantum *electrodynamics* - electromagnetism only, other particles/forces not invited! (Yes, this includes the weak force - otherwise QED would be quantum electroweakdynamics).

          b) is to be expected, as a general unified theory doesn't exist yet, and a) is a simple extension of physicists who live in a macroscopic world trying to assign macroscopic ideas to a microscopic system (i.e. the 'location' of an electron). Any of Hund's rules could be seen to be ad-hoc as well, but a bit more theory and it all makes sense.

          Now, if you mean the *Standard Model* is filled with ad-hoc rules, you're right. Neutrinos are all left handed... kindof. That sort of thing. That's correct. But QED is quite a solid theory.

          GR is also anything but incredibly simple. It's simple only in the limit where you can take the interaction between two objects to be significantly greater than the Planck length, but anything smaller than that, and GR isn't so simple anymore. Simple reasoning: GR is continuous, QED is quantized. We can pull QED out from the quantized limit back to good old electrodynamics easily, but GR isn't nearly as lucky.

          And, yes, I am a physicist as well, but I don't work in units where c is one. :)
      • That's an interesting thought, but I know of no evidence that it might be true. The passage of time is not a function of the speed of light. Observed passage of time is a function of the relative speed of the observer to the observee, but that's an entirely different thing.
        • This argument assumes that the passage of time is real. It may not be. At the human scale, this is a moot point since our consciousness is predicated on the perception of the passage of time, but at the fundamental level where there's CPT conservation it may be nothing but an illusion that distracts you from the truth.
        • As I understand it, the passage of time as we humans would care to measure it, or as our clocks would measure it, is based upon chemical and physical laws of nature, which depend on, among other things, the speed of light. The speed of light affects such mundane things as the strength of electromagnetic forces and the ratio of the the electric and magnetic constants to one another. Change the speed of light, and you change the rate at which all physical processes occur which we would use to measure time. If light moves slower, these processes move slower, and our sense of time has hence slowed, and light still travels at roughly the same speed.

          But as the previous comment pointed out, the unitless constant alpha is not renormalized by the slowing of physical processes, so this can be measured, and may have possibly changed over time.

          Also worth pointing out, is that phyiscal processes that happened billions of years ago with a "slower" or "faster" speed of light, could have happened at different rates because of altered electromagnetic strength and electric/mangnetic constant ratio, etc. This has been suggested as one explanation of redshifted light from distant objects. However, measurements of the constant alpha show only a very small change over time (if any), so the speed of light doesn't appear to have changed much at all over the last few billion years.

  • We never really know anything (Score:4, Interesting)

    by KarmaBlackballed ( 222917 ) on Tuesday December 04, 2001 @01:33PM (#2654445) Homepage Journal
    It is narrow thinking to propose that we ever have the "final" answer because there is no way to prove that something is right. We can only prove that things are wrong.

    Newton thought he had it covered, and the world agreed. Then Einstein came along and shook our understanding in strange ways. People got comfortable, then Schroedinger and his damn cats show up and screw things up again. Then we get comfortable. Then scientist discover that we still do not have whole story yet again.

    Don't you get it? The wonderfulness of it all is that we will never know it all. The beauty of creation is that we will always have something more to discover.
    • Well, almost - I think a significant part of the "wonderfulness of it all" is how much we do know, and how much more we continue to learn that's true (on top of which, as you said, there always is/will be more to learn).

      This is all worthless intellectual masturbation if there's no real learning involved.
    • The beauty of creation is that we will always have something more to discover.

      How do you know?

    • Re:We never really know anything (Score:2, Insightful)

      by Anonymous Coward
      It is narrow thinking to propose that we ever have the "final" answer because there is no way to prove that something is right. We can only prove that things are wrong.

      what ?? perhaps you have some convoluted idea of proof. all the things you mention are theories, no proof was given. i agree there is something always more to discover, but why do you think we can disprove something then?

      also, as a studying mathematician, i do believe that we can proove and disprove things absolutely. to think otherwise is incredibly naive given the relative success of humanity.

      • Re:We never really know anything (Score:5, Insightful)

        by dangermouse ( 2242 ) on Tuesday December 04, 2001 @02:16PM (#2654651) Homepage
        also, as a studying mathematician, i do believe that we can proove and disprove things absolutely. to think otherwise is incredibly naive given the relative success of humanity.

        Mathematics is entirely artificial. It's based on rules and premises that we pretty much made up. You can prove things in math because it's a self-contained problem set, and you're looking at it from the outside with an omniscient view.

        When you didn't invent the framework of the problem, it tends to be harder to prove a solution.

        That said, you may never be able to prove a Unified Theory, because you can't ever be certain you've described every aspect of the problem set. But you can disprove a physical theory (or at least show it to be lacking) simply by finding a counterexample.

      • Mathematics is the only science which can prove things in any absolute sense, because it does not depend on experimental results. The theories in any experimental science are only as good as the limits on the accuracy of the experiments. A prime example is Newton's laws: they looked like they were completely true when they were written down and published, but we know now that they are only slightly wrong when dealing with things roughly the size and speed of people, and grossly inadequate when dealing with really high energy objects. To paraphrase the original poster, experimental sciences cannot distinguish between "right" and "wrong," they can only distinguish between "wrong" and "not very wrong."

      • also, as a studying mathematician, i do believe that we can proove and disprove things absolutely. to think otherwise is incredibly naive given the relative success of humanity.

        as a mathematician, i expect you are well aware of what happens when premisses are incorrect. also as a mathematician, i *hope* you are aware that because it is a logic system - a conceptual entity with no necessary binding to reality - mathematics is capable of 'proof'.

        i urge you to take a few *good* classes (bad classes will be a waste of your time, perhaps independent study would be better) in epistemology. it may not change your mind, but it might change your mind.

        in any case, i think it's rather naive to believe that our proofs accurately and precisely describe reality. to think otherwise is incredibly optimistic, given the relative success of humanity. (i mean, how hard is it for a species to survive? and how long have we been here? the odds are against us just as much as they are against the cockroach. our "knowledge" does not separate us from our ecology.)

        we're trying to build working models of our environment, so that we may predict it with greater success. none of this implies proof, no matter how well it may seem to work.


      • as a studying mathematician, i do believe that we can proove and disprove things absolutely

        As a studying mathematician, you should be familiar with Godel's Incompleteness Theorm, and realize that there are true statements within any consistent axiomatic system that can never be proven.

    • Re:We never really know anything (Score:5, Insightful)

      by tijnbraun ( 226978 ) on Tuesday December 04, 2001 @01:51PM (#2654544)
      This reminds me of pascal's image of knowledge...
      Where knowledge is symbolized by the sphere's volume and the unknown by the sphere's surface. Therefore as knowledge grows, so does the unkown (although the volume grows faster than the surface, total wisdom will be never achieved.)

      (or if the sphere is a balloon, science grows until it explodes :)

    • Re:We never really know anything (Score:5, Insightful)

      by dragons_flight ( 515217 ) on Tuesday December 04, 2001 @02:13PM (#2654634) Homepage
      You are forgetting something. Before the great paradigm shifts in the history of physics (Newton, Einstein, Bohr, etc.), there was always evidence that something was wrong with prevailing theory. Scientists on the front lines weren't "comfortable", they noticed things like the "ultraviolet catastrophe" and the precise spectra of atoms and knew something was wrong.

      Today we know that general relativity and quantum mechanics don't work together, but we aren't sure how to fix it (though string theorists try hard).

      Eventually it's conceivable that we'll write down some basic laws and then millenia will pass without any evidence that something is still wrong. While you're right that it's impossible to prove that these laws are correct, scientists are very diligent about trying to find holes and if none are found, then everyone will believe we finally know the truth. And perhaps we actually will.
      • Actually, the previous theories were not wrong, just limited in accuracy. Newtonian physics are a kind of approximation of GR, which will probably be a approximation of UF forms. They hold true to thousands of decimel places at everyday conditions, but when things get extreme, values change.

    • Re:We never really know anything (Score:5, Funny)

      by blamario ( 227479 ) on Tuesday December 04, 2001 @02:32PM (#2654727)
      To quote (by memory) from the Hitchhikers' guide:

      There's a theory saying that, if we ever figure out the Universe, it will be immediately replaced by something even more complicated. There's another theory saying that already happened.
    • I dislike this thinking. What ever happened to truth and reason? Why can't I walk outside and know that a rock will never turn into a bird?
    • Alright, i'll bite here.

      We can only prove that things are wrong.

      Perhaps, but it is, however a matter of how you state your problem.


      Assertion: Life exists on other planets.

      Proof: Finding life on another planet.

      Disproof: Can't be done without visiting every planet and verifying that there is no life on it.

      Here you prove something true.

      I am not saying that you are wrong to say that we will never know the whole truth as to what happens in the universe, you are absolutely correct. There will always be more to discover, but making the blanket statement that you can't prove anything true, only false.... well, that's incorrect (by counterexample, as it happens :)

  • Limiting factors (Score:3, Insightful)

    by TheSHAD0W ( 258774 ) on Tuesday December 04, 2001 @01:34PM (#2654446) Homepage
    Absolutely. Einstein's theories superseded Newtonian physics, though Newton's system works just fine for most things here on Earth. It's only when one approaches the speed of light that you find the discrepancies pointed at by Relativity -- and discover how matter and energy interrelate.

    Einstein's work may also not adequately describe the universe in some instances; it cannot satisfactorially explain how the universe came into being. A new theory that can do so can hopefully be found -- and if it is, it will very likely teach us new things, things that may affect our every day life, just like Einstein has.
    • not to mention that one good ear marking of a theory that has limits is when you have discovered an undefined solution (like blackholes) where classical Physics failed at high speeds etc. GR fails at high gravitational forces....not to mention that the speed of light thing is a bit off (if you can pass through a worm hole and end up in antoher location, you have, reletive to the onlooker, gone faster than the speed of light and infact almost exist in 2 locations at once.) but that will all get hashed out in the final stableised theory that these gents come up with.
      • GR fails at high gravitational forces

        No. General relativity only becomes noticable at high gravitational forces (or under strong acceleration).

        (if you can pass through a worm hole and end up in antoher location, you have, reletive to the onlooker, gone faster than the speed of light and infact almost exist in 2 locations at once.)
        No. GR allows for solutions where the "fabric" of spacetime is so "warped" that, while an object traveling through that region (wormhole) never exceeds c locally, over the entire path it may appear to an outside observer that c was exceeded. This is entirely consistent with GR. (As to whether it can actually happen, that's a different issue entirely!)
        • I will conceed #2 however, GR fails at very high gravitational forces as is evident with a sigularity. just because it says that space is undefined does not mean that it is the real answer. classical physics said that magnetic lines of polarity were not connected when the magnet moved...guess what, they are and maxwell proved it. the theory was wrong. it can be right for a lot of stuff but if it is wrong in describing a system it is just wrong period.

    • Actually... (Score:2, Insightful)

      by epepke ( 462220 )

      Special Relativity didn't supersede Newton's laws of motion.

      They superseded the classical viewpoint that momentum was speed times a constant mass, but to his credit, Newton never made this claim. His students did. In modern form, F=dp/dt still works under SR.

      They also superseded the Galilean transformations by the Lorenz transformations, but that was Galileo's problem, not Newton's.

      I'm being picky because I think Newton gets a bad rap and doesn't deserve it for the laws of motion. They're still good. On the other hand, GR certainly does supersede Newton's law of gravity, and in that case the criticism is valid.

  • Arguing with Theory? (Score:3, Informative)

    by FortKnox ( 169099 ) on Tuesday December 04, 2001 @01:34PM (#2654448) Homepage Journal
    Arguing with theory (especially Relativity) is not uncommon. The only way theories become so well supported is trial by fire.

    I'm all for arguing with the theory, but more interested in the result.

    Since we are talking Unified theory, please allow a shameless plug to my fav String Theory site [superstringtheory.com].

  • Okay, Here It Is (Score:5, Informative)

    by The Gardener ( 519078 ) on Tuesday December 04, 2001 @01:34PM (#2654452) Homepage
    December 4, 2001

    Challenging Particle Physics as Path to Truth


    By GEORGE JOHNSON


    n science's great chain of being, the particle physicists place themselves with the angels, looking down from the heavenly spheres on the chemists, biologists, geologists, meteorologists -- those who are applying, not discovering, nature's most fundamental laws. Everything, after all, is made from subatomic particles. Once you have a concise theory explaining how they work, the rest should just be filigree.

    Even the kindred discipline of solid-state physics, which is concerned with the mass behavior of particles -- what metals, crystals, semiconductors, whole lumps of matter do -- is often considered a lesser pursuit. "Squalid state physics," Murray Gell-Mann, discoverer of the quark, dubbed it. Others dismiss it as "dirt physics."

    Recently there have been rumblings from the muck. In a clash of scientific cultures, some prominent squalid-staters have been challenging the particle purists as arbiters of ultimate truth.

    "The stakes here are very high," said Dr. Robert B. Laughlin, a Stanford University theorist who shared a Nobel Prize in 1998 for discoveries in solid-state physics. "At issue is a deep epistemological matter having to do with what physics is."

    Last year Dr. Laughlin and Dr. David Pines, a theorist at the University of Illinois and Los Alamos National Laboratory, published a manifesto declaring that the "science of the past," which seeks to distill the richness of reality into a few simple equations governing subatomic particles, was coming to an impasse.

    Many complex systems -- the very ones the solid-staters study -- appear to be irreducible. Made of many interlocking parts, they display a kind of synergy, obeying "higher organizing principles" that cannot be further simplified no matter how hard you try.

    Carrying the idea even further, some solid-state physicists are trying to show that the laws of relativity, long considered part of the very bedrock of the physical world, are not platonic truths that have existed since time began.

    They may have emerged from the roiling of the vacuum of space, much as supply-and-demand and other "laws" of economics emerge from the bustle of the marketplace. If so, then solid-state physics, which specializes in how emergent phenomena occur, may be the most fundamental science of them all.

    "We're in the midst of a paradigm change," Dr. Pines said. "Ours is not the prevailing view, but I think it will turn out to be the one that lasts."
    Working in this vein, one of Dr. Laughlin's Stanford colleagues, Dr. Shoucheng Zhang, recently was co- author of a paper suggesting that elementary particles like photons and gravitons, the carriers of electromagnetism and gravity, might not be so elementary after all -- they might emerge as ripples in the vacuum of space, bubbling up from the quagmire in a way that can best be explained in terms of solid-state physics.

    "The idea is of course crazy, thought provoking, and somewhat anti-establishment," Dr. Zhang said. "The main idea is to apply concepts from solid-state physics to answer some big questions of the universe."

    The particle physicists insist that there is plenty of mileage left in their own approach. "I strongly believe that the fundamental laws of nature are not emergent phenomena," said Dr. David Gross, director of the Institute for Theoretical Physics at the University of California at Santa Barbara. "Bob Laughlin and I have violent arguments about this."

    After hearing Dr. Zhang describe his theory at a seminar last month, Dr. Gross deemed it "an interesting piece of work." He said he found the mathematics "beautiful and intriguing, and perhaps of use somewhere."

    That may sound like faint praise, but the particle physicists have reason to be wary. The squalid-staters are challenging them in a debate over how the universe is made and how science should be done.

    Following the method of Plato, the particle physicists are inclined to see nature as crystallized mathematics. In the beginning was a single superforce, the embodiment of an elegant set of equations they call, only a bit facetiously, the theory of everything. Then along came the Big Bang to ruin it all.

    The universe cooled and expanded, the single force splintering into the four very different forces observed today: electromagnetism and the weak and strong nuclear forces, which work inside atoms, are described by quantum mechanics and special relativity. The fourth force, gravity, is described by an entirely different theory, general relativity.

    The particle physicists' ultimate goal is "grand unification" -- recovering the primordial symmetry in the form of a single law -- a few concise equations, it is often said, that could be silk-screened onto a T- shirt.

    This approach, in which the most complex phenomena are boiled down to a unique underlying theory, is called reductionism.

    The problem, the solid-staters say, is that many forms of matter -- ranging from the exotic like superconductors and superfluids to the mundane like crystals and metals -- cannot be described in terms of fundamental particle interactions. When systems become very complex, completely new and independent laws emerge. "More is different," as the Nobel laureate Philip W. Anderson put it in a landmark paper in 1972. To the solid-staters, it would take something the size of a circus tent to hold all the equations capturing the unruliness of the physical world.

    Like Aristotle, they lean toward the notion that it is the equations that flow from nature instead of the other way around. Mathematics is just a tool for making sense of it all.

    "For at least some fundamental things in nature, the theory of everything is irrelevant," declared Dr. Laughlin and Dr. Pines in the Jan. 4, 2000 issue of The Proceedings of the National Academy of Sciences. "The central task of theoretical physics in our time is no longer to write down the ultimate equations but rather to catalog and understand emergent behavior in its many guises, including potentially life itself."

    There may not be a theory of everything, they say, just a lot of theories of things. This is exactly the kind of squalor the particle physicists abhor.

    Dr. Grigori E. Volovik, a solid- state physicist at the Helsinki University of Technology in Finland, champions an idea he calls "anti- grand unification." In a review article last year (xxx.lanl.gov/abs /gr-qc/0104046), he ventured that the universe may have begun not in a state of pristine symmetry but in one of lawlessness. The laws of relativity and perhaps quantum mechanics itself would have emerged only later on.

    The notion of emergent laws is not radical in itself. A flask of gas consists of trillions of molecules randomly colliding with one another. From this disorder, qualities like temperature and pressure emerge, along with laws relating one to the other.

    So take that idea a level deeper. Physicists now believe that the vacuum of space is, paradoxically, not vacuous at all. It seethes with energy, in the form of "virtual particles" constantly flitting in and out of existence. So perhaps, Dr. Volovik suggests, even laws now considered fundamental emerged from this constant subatomic buzz.

    Solid-state physics offers clues to how something like this might occur. The atomic vibrations that ripple through matter are, like all quantum phenomena, carried by particles -- called, in this case, phonons.

    Just as photons carry light and gravitons carry gravity, phonons carry the subatomic equivalent of sound. Like bubbles in a carbonated beverage, phonons -- physicists call them "quasi particles" -- appear only when the medium is disturbed.

    In the world of solid-state physics, quasi particles abound. In some substances, like the semiconductors used to make computer chips, the displacement of an electron leaves behind a "hole" that behaves like a positively charged particle. An electron and a hole can sometimes stick together to form a chargeless quasi particle called an exciton. Other such ephemera include magnons and polarons.

    Evanescent though they are, quasi particles act every bit like elementary particles, obeying the laws of quantum mechanics. This has led some mavericks to wonder whether there is really any difference at all. Maybe elementary particles are just quasi particles -- an effervescence in the vacuum.

    Particularly intriguing is a phenomenon, occurring at extremely low temperatures, called the fractional quantum Hall effect. In certain substances, quasi particles appear that act curiously like electrons but with one-third the normal charge. (Dr. Laughlin won his Nobel Prize for a theory explaining this.)

    Quarks, the basic building blocks of matter, also carry a one-third charge, a coincidence that has fueled speculation that emergence may be somehow fundamental to the very existence of the physical world.

    A stumbling block to carrying this idea further has been that the quantum Hall effect seems to work only in two-dimensions -- on the surface of a substance. But in a paper published in the Oct. 26 issue of Science, Dr. Zhang and his student Jiangping Hu showed how to extend the phenomenon. In their scheme, the physical world would be a three-dimensional "surface" of a four-dimensional "quantum liquid" -- an underlying sea of particles that can be thought of as the vacuum.

    Analyzing the ripples that would appear in such a medium, the two scientists were surprised to find that they mathematically resembled electromagnetic and gravitational waves. But there are problems with the model. At this point, the hypothetical photons and gravitons that emerge from the equations do not interact with other particles, as they do in the real world.

    "The coupling is zero, so apples are weightless, as is everything else," said Dr. Joseph Polchinski, a string theorist at the University of California at Santa Barbara, who recently discussed the model with Dr. Zhang.

    And there is what the theory's inventors concede is an "embarrassment of riches" -- the equations predict hordes of exotic particles that do not exist.

    "The hope is that some modification of the theory, not yet specified in detail, will remove the extra fields and turn on the coupling," Dr. Polchinski said. "Whether this can be done is at this point a guess. Overall my attitude now is interest with a high degree of skepticism."

    If the theory can be made to work, it may point to a new way of unifying quantum mechanics and relativity. But Dr. Zhang is careful not to oversell what he considers a work in progress.

    "Our work only made a tiny step toward this direction," Dr. Zhang said, "but it seems to indicate that the goal may not be impossible to reach." At the very least, he said, his work may inspire more collaboration between particle physicists and solid-staters.

    Ultimately, though, the two sides know that they are talking across a divide. Taken to its extreme, emergence suggests that all the fundamental laws, even quantum mechanics, may be secondary -- that at the base of reality is random noise.

    Dr. Polchinski said he found that idea discouraging.

    "To me, the history of science seems to be a steady progression toward simpler and more unified laws, and I expect to see this continue and to contribute to it. Things may take many surprising twists and turns," he said, "but we reductionists are still quite happily and busily reducing."

    • "They may have emerged from the roiling of the vacuum of space, much as supply-and-demand and other "laws" of economics emerge from the bustle of the marketplace. If so, then solid-state
      physics, which specializes in how emergent phenomena occur, may be the most fundamental science of them all.

      If they are right and (some) higher-level laws are irreducible to particle physics, then solid-state physics probably won't be "the most fundamental" either. Any discipline that contains irreducible laws (economics? cognitive science? evolution?) will be in some sense "fundamental".

    • Not Really (Score:5, Informative)

      by nahtanoj ( 96808 ) on Tuesday December 04, 2001 @01:55PM (#2654558)

      Speaking as part of the community, the physics world is not at all portrayed accurately in this article. Nearly every physicist sees value in every subset of physics. Think nuclear physics is dead? I happen to know a few nuclear physicists who are still active in research. No-one I know refers to solid-staters as "squalid-staters". There is worthwhile research still in every discipline of physics, even solid state and particle physics.

      I think what we have here is a case of journalistic hype used to make the a mountain out of a molehill. I do not think that anyone can deny that there has not been advances in the understanding of any field.

      Ciao

      nahtanoj

    • Re:Okay, Here It Is (Score:5, Interesting)

      by Beryllium Sphere(tm) ( 193358 ) on Tuesday December 04, 2001 @02:13PM (#2654637) Journal
      This is really a philosophical argument, not a scientific one. But it may be a productive one. And I bet computers have caused the argument.

      For a long time humans lived in a world with cats and cookware. Human-made items like cookware were trivial to understand, and nobody hopes to understand a cat :-)

      Then we got a little more sophisticated and had cats and clocks. We studied clocks because we could understand them. We learned about energy conservation, simple harmonic motion, and all sorts of classical physics. Reductionists can learn to understand a clock.

      Then we had computers and cats. A computer looks like an elaborate clockwork but practical people don't try to manage them through first principles. They use heuristics like "it gets unstable when low on memory". Now we've got human-made artifacts, which we feel entitled to understand, which reductionism has increasing trouble explaining.

      The promise here is that if we apply the same brainpower and effort to defining the laws of complex systems, maybe we'll gain some useful insights into economics, sociology, psychology and other fields of study which directly affect our lives.

      I will not hold my breath waiting for a definitive theory of cats.
      • If you think this is a philosophical argument, then I think you missed the point.

        The most important point isn't whether there are emergent organizing principles at different levels, because everyone knows there are. The real arguments is whether or not "fundemental" particles are really real. The particle physics community believes they've got a grasp on the basic building blocks of reality, but then some solid state boys come along and offer a theory saying they don't really exist at the base of things.

        Think of it this way. In the particle physicist mind, you don't need vacuum fluctuations to describe particles. They both have an independent existance. The solid state people have suggested that all particles are merely a consequence of the vacuum fluctuations. You can't have particles without the background.

        While the two conflicting viewpoints do arrise from different philosophies, it also seems clear that there is an underlying truth. Either there are particles in full truth, or there is just a vacuum that makes it look like there are fully qualified particles. Ultimately it's the truth that's important, and this seems like an important difference to me.
  • General relativity didn't start until, like 1916 or something.

  • In nearly every field (Score:3, Funny)

    by localman ( 111171 ) on Tuesday December 04, 2001 @01:42PM (#2654496) Homepage
    It sounds a bit like the argument between Java and Perl to me :) There are those who believe that things that are clean and orderly are "right" and there are those that believe things that are loose and flexible are "right". (There are those that believe that life here began... out there...)

    In any case it's an interesting path to explore. I lean towards the loose and flexible side myself. If you saw my code you'd be able to tell ;)

  • This Makes Me Nervous... (Score:5, Funny)

    by Embedded Geek ( 532893 ) on Tuesday December 04, 2001 @01:43PM (#2654504) Homepage
    I am I the only one, but is anyone else worried that when they finally find the unified theory, "The Theory that Explains Everything," that it'll wind up being Murphy's Law?

  • Physics War! (Score:3, Funny)

    by Happy Monkey ( 183927 ) on Tuesday December 04, 2001 @01:45PM (#2654514) Homepage
    General Relativity orders a positive charge, but comes under fire from ballistic missiles. It's time for a negative charge!

  • What ought to be noted is that theoretical physics is in a state of flux. The current methods and theories are showing cracks. For that reason, several competing theories are coming about.

    One of the primary things to think on, though, is not whether or not current theory ought to be completely discarded, but rather the theory just needs some small adjustments. *grinz* Even those 'minor' adjustments are often hotly debated.

    Even then, the one phycist friend of mine at FERMI said that theory only advances as the older generation dies off...;)

  • My Very Own Theory (Score:3, Funny)

    by pagsz ( 450343 ) <pagsz81@yahoo.com> on Tuesday December 04, 2001 @01:54PM (#2654554) Journal
    IANAP (Physicist, naturally), but I'd have to say that the solid-staters argument makes sense. It seems arrogant to think that the universe must obey these silly little laws we come up with. Mathematical laws are a tool, they simpify the workings of the universe so a human mind can grasp them. But they are not the universe. I would tend to agree with thier arguement that as systems get more complex, new rules come into play. How then can the universe's intricate workings be summed up in a few silly little equations?

    I've found the answer! The universe isn't dominated by some elaborate unified theory, or general relativity, or quantum mechanics, or anything like that. I've found a principle that applies everywhere. Everywhere I look, there it is. The central principle of the universe is: STUPIDITY! It all makes sense now . . .

    Well, at least its the central principle in my life,
    • This reminds me of the old joke:
      Engineers think the equations approximate reality. Scientists think reality approximates the equations. Mathematicians never make the connection.

      J:)
    • There are two problems that you need to remember:

      One is, if your theory is REALLY good, you can show why something is from very basic principles. Thus, you don't have any precepts to start on other than a few basic ones. For instance, you can say "particles have spin?" and someone may say "yes, but at some time, spin might not have existed." If your theory is extremely good, you can say what would happen if spin didn't exist. In actuality, relativity already says that - if spin didn't exist at some point in time, then relativity wouldn't have existed - that is, spacetime wouldn't have a 3+1 signature.

      Conversely, if we find evidence of spin, that implies that spacetime has (at least) a 3+1 signature, or at least has some symmetry which posesses 2 Casimir invariants.

      Physics isn't generating 'laws' that have to be 'obeyed'. We're saying "the universe IS this way, that IMPLIES this", we check it against experiment, and *that* can't change. We know, for instance, that conservation of energy holds because the universe is time-symmetric. If we abandon conservation of energy, we have to assume that the universe is NOT time-symmetric, which disagrees with tons upon tons of experiments (including ones which measure all the way back to 300,000 years after the big bang, so we at least have to assume that conservation of energy has held for ~10 billion years).

      This is why astrophysics is important - it tells us "how constant are the 'silly little laws' we come up with?" and trust me, based on what we've seen so far in astrophysics, my God, they're constant.

      (Just as an example - it was once thought that gravity's strength changes over time - with the density of the Universe. This is Brans-Dicke theory. We now know that Brans-Dicke theory, if it is correct, contributes very VERY negligibly to gravity's strength. That is, if gravity *has* changed over time, it hasn't changed *much*.)
  • also explains certain thinks like matter as ripples in space time.....it is kind of interesting how this aspect of the theories match up.

  • Ugly Standard Model (Score:3, Interesting)

    by Genady ( 27988 ) <gary.rogersNO@SPAMmac.com> on Tuesday December 04, 2001 @02:00PM (#2654582)
    All I can say is well DUH! I'm not expert, but I have read a few things about super string theory and have to say that it really is more elegant than the standard model, the theory that particle physists use. Just fom a cursory glance at this article it sounds like the solid-state folks are proposing something similar to the super stringers. That particles are at their root a function of space and how it vibrates.

    What I'd really like to see is some comparison between this new theory and string theory (it could be in there I didn't read past what was posted here)

  • Sensationalist article, but neat idea (Score:4, Interesting)

    by ErfC ( 127418 ) on Tuesday December 04, 2001 @02:15PM (#2654646) Homepage
    I found the article kind of sensationalist. I mean, I'm sure there are physicsists who act like that, and I'm not surprised these are the ones that make it into newspaper articles. But I don't think most physicists are so violently opposed to each other's ideas.

    I mean, okay, most of us are at least a little arrogant. We're revealing the secrets of the Universe -- how could our heads not swell, at least a little? But for most of us it's a little tongue-in-cheek, too.

    Now the ideas in the article intrigue me. I'm in Particle Physics, and I was indeed under the impression that fundamental particles are, well, fundamental. The idea that this could all be quasi-particles ("effervescence in the vacuum" as the article puts it) like phonons (the sound equivalent of photons) in matter, is really cool.

    I will agree with this much: there isn't enough discussion between the various disciplines. Scientists in general need to talk to each other more.

  • Omega Number (Score:2, Informative)

    by faichai ( 166763 )
    See This Story [slashdot.org] for details. The New Scientist link is now dead look here [dc.uba.ar] instead.

    If I am reading things correctly it would seem, that both the "Squalid Staters" and Chaitin are coming from the same angle. Both reckon that any maths we can derive to describe the physical world are almost fluke, and that underlying everything is sheer randomness. Fascinating Stuff. Can anyone offer a more qualified comparison of these two areas?

  • i'm glad to see the theory of everything crowd take a hit. their absolutism can be compared to religious fundamentalism.

    the solid staters talking about the universe being nothing but noise from which various descriptive rules emerge, but dependent on no other larger organizing principle, is satisfying to me.

    allow me to be a crank about something that always bothered me: i never liked the big bang theory. it stinks of creationism. it seems out of line with the trend of what humanity has been learning from science over the last thousand years: that the universe is random, trivial, makes little sense, and we are not anywhere near the center of it.

    it doesn't all boil down to an equation on a t-shirt? woop-de-friggin'-doo. just because us humans are reductionist thinkers and anal-retentive "everything in my world has to make sense" psychological types doesn't mean the universe has to fit that template. there does not have to be a theory of everything for the universe to work. it doesn't need a beginning, it doesn't need an end. the universe can be timeless, static, and random. what's wrong with that?

    expansion of the universe? why can't the expansion we see be local, temporary. like being on the trough of a wave in the ocean, only able to look around in the trough we're in and see the trough expanding, unaware of the tips of the waves to our right and left. or unaware of the overall picture of us being in an endlessness ocean, infinite through space and time, backwards and forwards.

    background microwave radiation? merely the effects of only being able to see a certain distance. the night sky may not be glowing white even though there might be infinite stars in every direction, but after a certain distance, light can be lost through means beyond our understanding, or through merely mundane reasons we already understand: absorption? dark matter? gravity lensing?

    entropic death of the universe? or a big crunch in our future? why the absolutism? perhaps this might happen locally, and an as-of-yet unforeseen restoking of the entropy balance happening through processes we are not even aware of yet. black holes? they are singularities of some sort. i wonder what kind of bedrock rules we take for granted are broken in them. maxwell's demon indeed.

    do i sound quasi-rational, like i'm grasping at straws? maybe so, i'm no cosmologist. but the big bang stinks of creationism to me, and if anything we have learned historically trend-wise, through galileo, kepler, hubble, etc., is that our place in the universe is vanishingly small, pointless,and trivial. to speak of a creationistic big bang seems vaguely anthropomorphic and self-centered, like how we used to think the sun revolved around the earth.

    same with a theory of everything. why does gravity have to be united with any other forces? to satisfy a psychological urge? "it just is" sounds ok with me.

    just because us little humans have a beginning and an end does not imply the universe does. and just because we have to make little reductionist rules up to govern how we live our lives and make sense of it all does not mean the universe has to conform to our psychology.

    bravo to the solid staters. the dudes who gave us the silicon chip are telling us that the universe begins and ends with local rules dependent on nothing else. now that's a theory of everything i can live with: everything begins and ends with my computer. ;-P

    • Re:a breath of fresh air (Score:5, Interesting)

      by Some guy named Chris ( 9720 ) on Tuesday December 04, 2001 @03:46PM (#2655281) Journal

      i never liked the big bang theory. it stinks of creationism. ... i'm no cosmologist. but the big bang stinks of creationism to me ...

      So, let me get this straight. You are rejecting a reasonable theory which fits the observed behaviours simply because it conflicts with your religious (or anti-religious) beliefs?

      Isn't that what people accuse religious folks of daily?

      You aren't being logically consistant. You rail against anything with any hint of taint from our human experience, but at the same moment your rejection is based in how you feel about the existing theories. Stinks of creationism is a very visceral reaction to what you insist should be a completely rational debate.

      Face it. You have a philosophy guiding your argument as well. That philosophy is Nihilism [dictionary.com] and your post stinks of it.

  • L.E.J. Brouwer's "Life, Art, and Mysticism" (Score:5, Interesting)

    by Jagasian ( 129329 ) on Tuesday December 04, 2001 @02:24PM (#2654682)
    Here is a quote from the famous mathematician L.E.J. Brouwer [st-andrews.ac.uk], who saw the sciences as flawed due to their underlying philosophical foundations, which I think applies to the "Physicists War Over a Unified Theory":
    Every branch of science will therefore run into ever deeper trouble; when it climbs too high it is almost completely shrouded in even greater isolation, where the remembered results of that science take on an independent existence. The "foundations" of this branch of science are investigated, and that soon becomes a new branch of science. One then begins to search for the foundations of science in general and knocks up some "theory of knowledge." As they climb higher and higher confusion grows until they are all completely deranged. Some in the end quietly give up; having thought for a long time about the elusive link betwen the intuiting consciousness (which develops from the perceptional world) and the perceptional world itself (which in turn only exists through and in the forms of the intuiting consciousness) - a confusion which arose from their own sin of constructing a perceptional world - they then plug the hole with the concept of the
    ego, which was self-created with and at the same time as their perceptional world; and they say, "Yes, of course, something must remain incomprehensible, and that something is the ego that comprehends."

    But there are others who do not know when to stop, who keep on and on until they go mad: they grow bald, shortsighted, and fat; their stomachs stop working properly; and moaning with asthma and indigestion they fancy that equilibrium is within reach - and almost reached. So much for science, the last flower and ossification of culture.

  • These are, IMHO, the key points in the whole article:

    "Like Aristotle, they [(the emergent propossers)]lean toward the notion that it is the equations that flow from nature instead of the other way around. Mathematics is just a tool for making sense of it all."

    "[...]he ventured that the universe may have begun not in a state of pristine symmetry but in one of lawlessness. The laws of relativity and perhaps quantum mechanics itself would have emerged only later on."

    "Ultimately, though, the two sides know that they are talking across a divide. Taken to its extreme, emergence suggests that all the fundamental laws, even quantum mechanics, may be secondary -- that at the base of reality is random noise."
  • Ok, now that I've actually read through all of it... Ummm could someone please tell the reporter that General and Special relativity don't have much to do with particle physics?

    General and Special relativity are theories of the large, describing gravity and the warping of space/time due to gravity.

    Quantum Mechanics is the theory of the small, at the particle and sub-atomic level and it's a nasty dirty theory that has all kinds of exceptions and sepcial rules.

    The problem in particle physics today is that you can't join Relativity and Quantum Mechanics without some nasty consequences, infinities, zeros and things that don't make much sense. Not that physisits haven't tried. The current merger of Relativity and Quantum Mechanics is the Standard Model. Which works but doesn't expain WHY it works.

    The String theorists have a theory that does merge Relativity and Quantum Mechanics, and solves the problems of inifinities and zeros, however current string theory is only an approximation and isn't refined enough for experimentation yet. That is predictions from String Theory can't be tested in the lab at the energies that are available. Who knows you may only be able to test string theory with a big bang, and then look out everything starts over again.

    Again, I'd be interested to see a piece on this in Scientific American or some other Science journal that can delve a little deeper into the solid-state theory and see where it fits between the Standard Model and String Theory.

    I do wonder if the solid-staters look at things in 10 or 11 dimensions do they start looking like strings?

  • G.U.T. is WAR! (Score:5, Funny)

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  • Getting rid of causality? (Score:5, Interesting)

    by sab39 ( 10510 ) on Tuesday December 04, 2001 @02:34PM (#2654735) Homepage
    I remember reading an article some time ago in which a scientist proposed that Quantum Physics could actually be a natural corollary of General Relativity (where each particle is some kind of "ripple" in the space-time continuum), and that the mathematics of this could make sense if the requirement for Causality ("cause must happen before effect") were dropped from General Relativity.

    His proposal suggested that quantum coupling (where two particles can become intertwined based on an earlier interaction) was caused by some kind of ripple-effect going back in time from the observed particle to the time that the original interaction happened.

    He was able to explain many other aspects of Quantum Physics the same way, although he claimed that the mathematics was so complex that only the simplest of interactions had been formally proved to match between his model and QP - most of his theory, including the explanation of coupling, was hand-waving.

    I always thought that this theory seemed one of the most elegant I've ever heard - no need to introduce new hypothetical particles like Strings, no need to assume that all the complexities of the Standard Model are fixed, absolute and arbitrary. Just take General Relativity, drop Causality, and look at what emerges.

    I've often wondered whether this guy's theory ever went anywhere. It seems to have something in common with the theory proposed in this article - that QP is just an "emergent behavior" from GR. The difference is that the article seems to propose that there is no underlying rule at all except chaos and GR itself emerged from that; this guy proposed that GR was fundamental and QP was the emergent behavior.

    Anyone know anything about this theory or know where the original article might be? Did this guy have any success or get any recognition? Has his theory been actually disproved, or simply ignored?

    Stuart.

    • Richard Feynman (Score:2, Informative)

      by inKubus ( 199753 )
      Just do a search. The man WAS a genius. I also recommend the Feynman lectures on physics, the so called "red books". You will be sorely hurt if you do not check him out.
  • That's what the scientific method is all about. Disprove, disprove, disprove until a theory stands up to all tests... then take it down some more.

    Einstein's theory is likely far from correct, so we need to create a new one. Why must scientists hold to 'truths' that they know aren't? We're just getting closer to the truth as allow for more and more variables. We learn, theories improve.

  • If only all wars (Score:3, Funny)

    by LazyDawg ( 519783 ) <<lazydawg> <at> <hotmail.com>> on Tuesday December 04, 2001 @02:47PM (#2654848) Homepage
    If only so many wars were fought so civily, with publication of papers, logic and reason taking the forefront over all that gun-use and wasted effort trying to convince people with a big stick.

    Of course, on the other hand, there's always fighting wars with lawyers and tax-men. That qualifies as throwing papers and logic and math around, almost. Pseudo-logic and semi-science works great when you're dealing with human judges rather than mathematics.

  • Un Anticipated Consequences (Score:4, Informative)

    by Alien54 ( 180860 ) on Tuesday December 04, 2001 @03:24PM (#2655111) Journal
    This all seems to be fall out and unanticipated consequences of various things:

    1) the various quantum tunneling experiments, where the Mozart 40th Symphony was transmitted through solid metal at several times the speed of light. There is a good link here [aei-potsdam.mpg.de]. There was even a NOVA special or something on that (see that transcript here [pbs.org], - info about 2/3rds into the material)

    2) maybe something involving the research of Steven Wolfram [stephenwolfram.com] (developer of Mathematica [wolfram.com]), as seen in his forth coming book A New Kind of Science [wolframscience.com], which is very geeky, very bizarre, and right up this alley, and is supposed to be a rethinking of the very fundamentals of how science works. My head hurts already. This book is due for publication in January 2002, and is well worth pre-ordering.

    • I have never quite understood why FTL is supposed to be impossible. I'd like a physicist to explain.

      First of all, I do understand this: take a tin can, and accelerate it to .9999 C. Now accelerate it more. And more. No matter how much you accelerate it, it will never reach 1.0 C, let alone a speed faster than light. (As I understand it, relativistic effects make the apparent mass of the tin can increase, making it harder to accelerate, and as it gets more massive it takes more energy to accelerate it, such that it would take infinite energy to push it to C, and it would have infinite mass, clearly impossible. You can get arbitrarily close to the speed of light if you can pour enough energy in, but never reach it.)

      So far I'm happy. But now let's imagine a magic closet door, and its twin orbiting Alpha Centauri, about 4 light years away. You toss the can through the magic door on Earth and it pops out of its twin; never mind how this works. My understanding is that physics says it must take 4 years for the can to get there, that it is fundamentally impossible for it to get there sooner. This is the part I don't get. Why is this?

      It has something to do with causality and the speed of light: I've been told that if the can is able to get there faster than the speed of light, the can has essentially travelled back in time, and this is forbidden because we like to believe in cause and effect. But I still don't get it.

      P.S. If your answer to this question is "RTFM", please tell me which FM. I have already tried to figure this out by looking at physics books, and I'm clearly looking at the wrong ones.

      Thanks.

      steveha

      • Re:FTL? (Score:3, Insightful)

        by jaoswald ( 63789 )
        The reason this is forbidden is because of relativity of simultaneity. I don't know why this part of relativity is less well-remembered than the relativistic length-contraction and time-dilation, but it is really the key to almost all relativistic "paradoxes."

        In any FTL travel, there are two events, A: leave the origin; B: arrive at the destination. FTL travel is believed to be impossible because observers in different inertial frames of reference would disagree about whether A or B happened first! Since it is paradoxical to arrive before you have left, the events cannot be causally connected.

  • Check out Barrow and Tipler's book... (Score:3, Informative)

    by SIGFPE ( 97527 ) on Tuesday December 04, 2001 @03:51PM (#2655322) Homepage
    ...The Cosmological Anthropic Principle. It has some nice discussion of how the symmetries we observe in particle physics might 'emerge' from low energy regimes of physical systems that are in some sense lawless. In general it's an interesting book that discusses why we have order in the universe quite a bit. But the part on order apparently emerging from a lawless universe seems to be what the current discussion is based on.

  • I think I've got it... (Score:3, Funny)

    by rho ( 6063 ) on Tuesday December 04, 2001 @04:48PM (#2655706) Journal

    If a solid-state physicist hits a particle physicist over the head with a tree that fell in the woods while nobody's around, we can finally get Schrödinger's cat out of that box...

  • A quantifiable way to affect gravity (one of the fundamental forces of the universe) with the one most common to us, an electromagnetic force. Of course, your mileage may very as to how :). A good unified theory of life, the universe, and everything would do for gravity what E=MC^2 and quanutm physics did for nuclear physics and what Maxwell did for electricity - give us a way to possibly engineer it.

    Of course, lots of other crazy things might be possible then, too. All of it comes from a way to unite the fundamental forces, though. It's too bad more articles (and comments!) don't make this clear.
  • Yep it is! Or at least what must exist in order for there to be "Theory."

    equations [mindspring.com] along with concepts [mindspring.com]

    Then there is the gears and bearings that all this happens on... but you have to figure out how to get there, to that link.

    This ether field, this noise state from which all else comes out of..... What is the controlling factor that decides what comes out of the noise?

    Life has an aura that we can even photograph. The human brain generates energy that it uses and transmits, perhaps similar to being near high power lines and feeling the charge, but on a much different power level, in that the mind can more fully integrate with the ether/noise and cause something like a chain reaction and cause such forces to come out of the ether/noise. Like putting a filter on white noise causing some frequencies to be suppressed and others to be emphisized to get tone.

    Mind over matter? OH damn! Someone has a patent [slashdot.org] on that too!

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