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[ba-unrev-talk] Fwd: digital physics contd

Now, maybe we're getting somewhere... ;o)    (01)

>From: John McCrone <j.mccrone@btinternet.com>
>Subject:      digital physics contd
>Below is another good NYT article on Wolfram giving more evidence of the way
>the intellectual tide is running and why he is striking a chord with people.
>Howard suggests its no big deal - digital or continuous, who cares at the
>end of the day? But to me, it is very important to know whether reality is
>mechanical or organic at root.
>What is interesting about all this is that the actual models of the "new"
>physics - strings, CAs, the holographic principle, etc - are actually
>attempts to capture a more contextual causal picture. Strings are a big
>advance on point-particles as string properties are the result of contextual
>constraint. CAs also have the same self-organising, contextual logic. The
>holographic principle, based on the light-speed limitation on communication
>of information, is also SO and contextual. (And Feynman's sum over histories
>approach is another beautifully SO, contextual, view, even though its been
>around a while now).
>So the models (which are necessarily digital, or formal) are heading towards
>a continuous, or contextual, ontology as they get more detailed. But then
>the modellers turn round and draw the very opposite ontological conclusion
>about what they are doing. They proclaim they are discovering the world to
>be deeply digital, deeply discrete. The success of formal modelling proves
>This schizophrenic thinking is especially apparent in Lee Smolin's otherwise
>excellent Three Roads to Quantum Gravity. He starts by showing the
>self-creating power of a "relational" (ie: contextual) approach to the
>fabric of spacetime. But then ends up arguing the model is the reality - if
>the model models reality in terms of discrete information, then discrete
>information is all that there is.
>It seems that physicists can be driven arbitrarily close to a description of
>a continuous reality by their modelling efforts, but this only seems to
>leave them more convinced that their digital fictions are the reality :-).
>What's So New in a Newfangled Science?
>NYT Week in Review, June 16, 2002
>SCIENCE is a cumulative, fairly collegial venture. But
>every so often a maverick, working in self-imposed
>solitude, bursts forth with a book that aims to set
>straight the world with a new idea. Some of these grand
>schemes spring from biology, some from physics, some from
>mathematics. But what they share is the same unnerving
>message: everything you know is wrong.
>A self-employed British theorist named Julian Barbour
>recently argued that time doesn't exist, and Frank Tipler,
>a physicist with a theological bent, offered scientific
>proof, in "The Physics of Immortality," of an eternal
>hereafter. People still read Julian Jaynes's imposing 1976
>book, "The Origin of Consciousness in the Breakdown of the
>Bicameral Mind," which pinpoints when humanity first became
>self-aware, and (also from that era) the work of James
>Lovelock, inventor of the Gaia Hypothesis, holding that the
>earth - rocks, air and all - is a living, breathing
>But for sheer audacity - and intellectual salesmanship - it
>would be hard to beat Stephen Wolfram, whose 1,263-page,
>self-published manifesto, "A New Kind of Science," was
>holding its own last week atop Amazon's best-seller chart,
>along with "Divine Secrets of the Ya-Ya Sisterhood" and
>"The Nanny Diaries."
>In the long tradition of the scientific loner, Dr. Wolfram,
>a freelance physicist known among his colleagues for his
>abrasive and self-aggrandizing ways, has yanked the
>spotlight onto a strikingly counterintuitive idea - that
>the universe is really just a big computer, something that
>can best be described not by analyzing equations but by
>trying to figure out what kind of software it runs.
>That, however, is just half the story. By short-circuiting
>the traditional formalities of scientific publication, he
>has managed to offend not just scientists who think he is
>wrong but also some who think he is right. What hasn't
>always come across in the debate, which is shaping up as
>the intellectual skirmish of the season, is that Dr.
>Wolfram is not a lone voice in the woods.
>Interesting ideas rarely spring up in isolation. The vision
>Dr. Wolfram has so meticulously laid out in such an
>arresting manner is part of a movement some call digital
>physics or digital philosophy - a worldview that has been
>slowly developing for 20 years.
>Just last week, a professor at the Massachusetts Institute
>of Technology named Seth Lloyd published a paper in
>Physical Review Letters estimating how many calculations
>the universe could have performed since the Big Bang -
>10120 operations on 1090 bits of data, putting the
>mightiest supercomputer to shame. This grand computation
>essentially consists of subatomic particles ricocheting off
>one another and "calculating" where to go.
>As the researcher Tommaso Toffoli mused back in 1984, "In a
>sense, nature has been continually computing the `next
>state' of the universe for billions of years; all we have
>to do - and, actually, all we can do - is `hitch a ride' on
>this huge ongoing computation."
>This may seem like an odd way to think about cosmology. But
>some scientists find it no weirder than imagining that
>particles dutifully obey ethereal equations expressing the
>laws of physics. Last year Dr. Lloyd created a stir on
>Edge.org, a Web site devoted to discussions of cutting edge
>science, when he proposed "Lloyd's hypothesis": "Everything
>that's worth understanding about a complex system can be
>understood in terms of how it processes information."
>Naturally a lot of researchers, who consider computers no
>more than useful tools, react huffily to the suggestion
>that what they are doing is "old science." So far no one
>using the alternative approach has been able to match the
>equations of calculus in predicting, for example, the exact
>moment of last week's solar eclipse for any spot on the
>What the detractors are less likely to emphasize is the
>track record of traditional mathematical methods in
>forecasting, say, the recent gyrations in the stock market
>or the way a forest fire will burn. Here the usual methods
>of science are stretched to the limit - and that is where
>an influential minority of scientists quietly agree on the
>kind of cure Dr. Wolfram is so loudly prescribing:
>replacing equations with a different kind of mathematical
>device called algorithms, simple little computer programs.
>THIS would represent a true upheaval. Mainstream science
>is rooted in the notion that space and time form a
>continuum: a perfectly smooth expanse that can be precisely
>described by what mathematicians call the real numbers,
>those that can have an endless string of digits after the
>decimal point. This kind of mathematics - the basis of
>calculus - is undeniably powerful. Physicists can predict
>the characteristics of a single subatomic particle with an
>accuracy equivalent to, as Richard Feynman liked to say,
>estimating the distance between New York and Los Angeles
>within the width of a human hair.
>Why even think about replacing something that works so
>well? The problem is that when you put a few electrons
>together and throw in a sprinkle of neutrons and protons,
>the system that emerges rapidly becomes so complex that
>exact predictions are impossible. The infinitesimally
>precise numbers have a way of causing the equations to
>And that is where the contrarians rush in, proposing that
>reality is not continuous but discrete, with a smallest
>possible length and a smallest possible duration of time.
>Picture space-time as a kind of grid on which the universe
>unfolds tick by tick, like a pattern in a kaleidoscope or a
>program running on a computer.
>In expressing their awe at the mathematical nature of
>creation, physicists have playfully suggested that God is a
>mathematician. Why not make him a software engineer? The
>result, says Edward Fredkin, another early promoter of
>digital physics, "might be the beginnings of a new
>intellectual revolution comparable to what was spawned by
>the development of mathematics." (His own treatise is
>available on the Web at digitalphilosophy.org.)
>Had Dr. Wolfram been more demonstrative in parceling out
>credit to those who share his vision (many are mentioned,
>in passing, in the book's copious notes), they might be
>lining up to provide testimonials. It's the kind of book
>some may wish they had written.
>Instead they were busy writing papers, shepherding them
>through the review process, presenting them in conferences,
>discussing them at seminars and workshops - going through
>the paces of normal science. That is how an idea
>progresses. But sometimes it takes a bombshell to bring it
>to center stage.
>from John McCrone
>check out my consciousness web site
>          http://www.btinternet.com/~neuronaut/
>neuroscience, human evolution, Libet's half second, Vygotsky and more...    (02)