Weird Science

(Rudy Rucker is a guestblogger. His latest novel, Hylozoic, describes a postsingular world in which everything is alive.)

Looking back over the advance of physics over the last two hundred years, it's staggering to realize how much our world view has changed. As a science fiction writer, I'm always trying to imagine how much more things might change in the coming two centuries. The really hard thing to anticipate is the completely game-changing advances that occur every so often.

My sense is that, for one thing, we won't be using chip-based computers in two hundred years---any more than we use mechanical calculators now. That's why, in my recent novels Postsingular and Hylozoic, I've been speculating about a world in which our computations escape from our machines and filter into our ordinary matter.


Nick Herbert is one of my favorite offbeat physicists. One of his papers in particular is something I've thought about a lot over the years: "Holistic Physics, or, An Introduction to Quantum Tantra." Here Nick argues that our conscious minds display some of the same features as quantum mechanics. When we're not thinking about anything in particular, our thoughts evolve in a continuous, multi-universe kind of way---but when we focus on something, we carry out something like the quantum collapse that characterizes the process of measurement.


[Brain models from the Collection of Historical Scientific Instruments at Harvard University.]

As I've been saying, I think it's at least in principle possible that the quantum computations in ordinary matter might be capable of carrying out these same kinds of processes---which we normally associate with living, conscious minds. And Nick's paper helps you to think about this idea.

David Deutsch wrote a deep and technical paper about the topic of computation in arbitrary pieces of matter, called "Quantum theory, the Church-Turing principle and the universal quantum computer."

The basic idea is that quantum mechanical systems can act as universal computers, and it's generally believed that any universal computer can emulate a human mind (given the right program, and, aye, there's the rub).

One of our big problems is that we still have such an imperfect notion of how to build a software system that's like a human mind. The best idea along these lines that I've seen in the last few years is in the book On Intelligence, by Jeff Hawkins and Sandra Blakeslee.


Two more rich sources for futuristic ideas.

(1) The site---for instance look at their New Papers on Cosmology and Extragalactic Physics page. It blows my mind that you can so easily access all these wild new papers, easily readable in PDF form. Even if, for the average person, a lot of the writing is incomprehensible gibberish (like the backwards neon sign shown above), you can skate through and pick up some great concepts and buzzwords.

(2) The physicist John Baez's pages. Baez is a deep thinker and a gifted popularizer, adept at imparting the true strangeness of this world.

It's liberating to realize that, as always, we're very much on the edge of knowing what's really going on.


  1. Programming the Universe: A Quantum Computer Scientist Takes On the Cosmos (by Seth Lloyd) kinda gets at these ideas, too.

  2. anyone else thinking of alan sokal’s “Towards a Transformative Hermeneutics of Quantum Gravity”? :->

  3. Quantum bedspread:

    Nick Herbert’s 1985 book, “Quantum Reality”, explained eight different guesses about the nature of the physical reality underlying the mathematics of quantum mechanics.

    This bedspread, crocheted by V. Scott in the early 1990s, displays eight emblems, freely interpreted from page 20 of Herbert’s book, for each of the possible realities detailed by Herbert (in vertical order):

    Neorealism – the world is made up of “ordinary” objects
    Many-worlds – an increasing number of parallel universes
    Copenhagen interpretation, part 1 – no deep reality
    Consciousness creates reality
    Reality is an undivided wholeness (symbol: monad)
    Copenhagen interpretation, part 2 -reality is created by observation (symbol: an eye)
    The duplex world of Werner Heisenberg
    Quantum logic – the world obeys a non-human kind of reasoning

  4. Fun as it may be to consider “Holistic Physics” in writing science fiction, it’s not science. It’s tied to one philosophical interpretation of QM, disregards decoherence entirely, and relies primarily on formal similarities between the Copenhagen interpretation and poorly operationalized ideas of “consciousness”. There’s no discussion of how the quantum formalism would apply to consciousness whatsoever.

    Then there’s great lines like this:

    “Since magnetic fields can easily penetrate the brain and do not collapse wave functions, one possible candidate for an oblivious link between two brain centers might be a slowly varying magnetic field.”

    The notion that magnetic fields don’t induce “wave-function collapse” is rather interesting, as Stern-Gerlach devices (and MRIs) appear to do just that. Admittedly, it’s difficult to tell if a wave function has really collapsed experimentally, since the observables are identical whether you accept collapse in your interpretation or not, but these experiments show all the hallmarks of what a collapse should look like.

    It’s always fascinating to me that people with strong intellect, good education, and years of productive research under their belt can veer off into left field like this. I think there’s an XKCD about that. :)

  5. Nick Herbert tutored me years back. I am still fascinated by everything he told me about, even though I’m still struggling to understand it.

  6. Roger Penrose, wrote “The Emperor’s New Mind” describing his theory of ‘quantum consciousness’.

    I personally think the using quantum physics to describe biological phenomenon is kinda ridiculous, although admittedly I am absolutely no authority on the subject.

    How could my brain, operating at 96*F, possibly keep decoherence from occurring, while scientists struggle to do so in laboratory conditions operating at nearly absolute zero?

  7. Hmm, well the attached paper claims that QM and stochastic classical systems are still computers. The argument given seems to be–well, computers don’t give genuinely random numbers, but they get damn close.

    Still leaves me with a question:

    Suppose some future or alien race develops computers, robots, etc. based on differential analysers. In what sense are such computers still Turing machines?

    Or, better, a fly takes the input from its eye and directly varies the frequency of various muscle vibrations. That is, a fly does analog flight control: stimulus begets response without direction from a brain. In what sense is a fly a Turing machine?

    Tough luck, but a whole lot of nature still works on analog. A whole lot of nature is inseparable and nonlinear, which means that the very idea that EVERY system is a Turing machine is nonsense from the get-go.

    Hey–it’s OK–your model of the universe DOESN’T HAVE to apply to everything to be useful.

  8. Upon further reflection, I still have to say:

    Decoherence, decoherence, decoherence.

  9. Magnetic fields don’t indue wavefunction collapse?

    Possibly, a zero-gradient non-interacting magnetic field would not induce wavefunction collapse, but aside from that the statement would appear to be completely wrong. What is a photon but a bundle of electromagnetic fields? And where a magnetic field changes there you have with absolute, irrefutable certainty, an electric field as well. (Einstein showed that the two are essentially the same thing.) Electromagnetic interaction is pretty much the most basic way to induce wavefunction collapse: It’s done all the time in laboratories.

    My OWN crackpot theory is a different matter entirely, however.

    Having never been fully convinced of “many worlds”, my own idea I’ve been kicking around is that, “out there”, in the real world appart from our senses, all quantum possibilities are occurring (ie, human consciousness sits astride the multiverse), but that it is collective human consciousness that causes the wavefunction of the universe to collapse and be presented as just one of the possible states to our senses.

  10. ‘wavefunction collapse’ is the diffusion of quantum correlations out of the system you’re following.

    point is: If you can arrange for a quantum correlation to occur between different states of the same particle, it becomes a lot easier – experimentally – to notice that a correlation exists.

    Following a quantum collapse, the weird quantum behavior is still going on, in principle, but you don’t know where to look to find it because that correlation has become distributed between the states of one particle that you are still following, and a second particle or a sound wave somewhere in the apparatus that you’ve got no idea about.

    If you could measure the joint properties of that sound wave and your particle, you would still see all the goofy quantum interference effects, but if you’ve only got the particle to look at, the correlations appear to be missing and some mysterious ‘collapse’ has taken place.

    I think that a many-worlds hypothesis is not required to explain decoherence, or wavefunction collapse, it’s just correlations being left somewhere they can’t be accessed.

    I think the exciting prospect is that we won’t need a form of quantum mysticism to explain consciousness, either.

  11. Sokal. Heh heh.

    Too bad Cultural Studies et al. haven’t gotten that memo yet.

    David Chalmers has some stuff on QM and consciousness, and he’s a top-notch philosopher of mind.

    As for explaining consciousness, the best we’ll ever do is robust psychophysical laws. We might establish a macro-level causal closure of the physical. But we’ll never explain why this quale is paired with that token brain state.

  12. One of our big problems is that we still have such an imperfect notion of how to build a software system that’s like a human mind.

    Why build it from scratch? That would be like trying to engineer a whole living thing from scratch.

    Find it out there. Maybe it takes a universe-sized amount of matter to function like a human mind. That would be rather gnarly.

  13. As a scientist I’m all for people learning as much as they can about the amazing worlds of quantum mechanics and (separately in my opinion) the study of the brain. However, the idea of going and picking up ‘a few buzzwords and key concepts’, and nothing more is a perfect path to crackpottism. Generally, the thousands of such theories which are ‘formulated’ constantly are exactly fuelled by this thin veneer of knowledge with little of the deep understanding needed to make genuine progress.

    This is not to say don’t go out there and pick up the key concepts and buzzwords, but just keep in my that behind such things are worlds of complexity and subtleties which are what take years of study to understand.

  14. @21 – that’s a really neat project you linked.

    I meant trying to engineer a -whole- living thing, not model it. Like making a functioning living yeast cell from a pile of carbon black and multi-vitamins.

Comments are closed.