Ghosts in the Machine

A few days ago we made passing mention of the Oxford philosopher of science Nick Bostrom’s Simulation Argument, which makes the claim that we are probably living in some sort of Matrix-like computer program. This dismal notion, which we looked at a bit more closely back in May, was also the subject of a brief article in last week’s New York Times.

There are several worthwhile objections to Bostrom’s idea. One serious weakness, and the one that I’ve mentioned at every turn, is that the simulation argument rests on the assumption that actual consciousness can arise in any system that is running a suitable program. It is easy to see the appeal of this idea, given that our brains do seem to be in both the information-processing and consciousness-producing business, but the fact is that we don’t even have a coherent description of what consciouness is, let alone any solid knowledge of what, exactly, it is about our brains that enables them to produce it. While it may, perhaps, turn out to be that the right sort of information-processing is indeed all that’s needed, and that any similar program running on any suitable platform can manage the trick, we certainly don’t have any account of why that should be, or in virtue of what, in particular, one program might bring about a conscious mind while others wouldn’t. The brain is not only a hugely parallel information-processing machine, but also an enormously complex physical object, and it seems likely to me (here I agree with John Searle) that it is in virtue of some of its physical properties, as well as its abstract informational content, that the brain gives us our subjective awareness.

I also think Bostrom is underplaying the difference between simulations and reality: you can simulate a storm in a computer model, but the simulated rain makes nothing wet. You might argue that the simulated rain floods the simulated roads, and that the simulated wind knocks down the simulated trees, but Bostrom is flattening the hierarchy here: he is talking about actual consciousness — our own, in fact, which is as real as it gets! — arising inside his putative simulation. I see no reason to believe this is possible.

Another problem, of a different sort, is that Bostrom’s argument seems, for now at least, quite untestable and unfalsifiable, and therefore lies, arguably, beyond the realm of science. For that reason, quite a few people seem to be annoyed that the Times would have featured it in last Tuesday’s science section (on the first page, no less).

One who seems awfully vexed is Columbia mathematician, particle physicist, and author Peter Woit, who in his latest book Not Even Wrong: The Failure of String Theory And the Search for Unity in Physical Law joins Lee Smolin in criticizing string theory as an untestable, and therefore scientifically unproductive, waste of some of today’s brightest minds. Dr. Woit has a blog by the same name, and in it I found a lively thread, 50 comments long, addressing Bostrom’s argument, the article in the Times, what is and isn’t science, and a number of other things besides. This looks like a good, grumpy site of the sort I enjoy; readers are invited to take a look also. Onto the sidebar it goes.

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6 Comments

  1. bob koepp says

    Hi Malcolm –

    Woit has a number of good criticisms of string theory, but he goes too far in claiming it lacks proper scientific bona fides. Testability is a virtue, but theoretical advances, especially in cosmology, often need to mature before they can testable hypotheses can be crafted. Time will tell.

    Bostrom’s speculations, on the other hand, seem to me to simply skate past telling difficulties. If implementing the right program was all that it takes to be conscious, then any Turing machine, even one constructed from tinker toys (it’s been done!) would be potentially conscious. Somehow, that strikes me as bonkers.

    Posted August 21, 2007 at 8:18 pm | Permalink
  2. Malcolm says

    Bonkers indeed, or at least bonkers to imagine that Bostrom’s entertaining notion, which is entirely dependent upon consciousness-as-software, is worth taking seriously.

    Even the preposterous Matrix scenario still needed biological brains to occupy the vats.

    As you say, the history of science offers plenty of examples of correct hypotheses that were put forward before there were ways of testing them, for example atomic theory and general relativity (though Eddington did come through quite promptly in the latter case). I haven’t read Smolin’s or Woit’s critique of string theory (though I’ve seen some interviews with Smolin, who I think is an extremely gifted physicist and a very creative thinker, and have read his remarkable book The Life of the Cosmos, which is worth a post of its own). I’ve spent more time listening to string-theory evangelists like Brian Greene, and I do have to admit the theory is captivatingly beautiful. I should read Smolin’s and Woit’s arguments in depth. Certainly Smolin’s point, that if string theory is nothing more than pie in the sky we are squandering the careers of some of our brightest young scientists, is an important one.

    Posted August 21, 2007 at 9:26 pm | Permalink
  3. bob koepp says

    Yes, how scarce scientific resources are spent is an important question. I think Smolin is right to be worried that scientific talent and energy is being focused too exclusively on a particular approach to basic physical reality. And in fairness, I must grant that as a research program, string theory does appear to be developing in ways that are only very tenuously constrained by experiment.

    Posted August 21, 2007 at 10:24 pm | Permalink
  4. Interesting,

    Yes, how scarce scientific resources are spent is an important question. I think Smolin is right to be worried that scientific talent and energy is being focused too exclusively on a particular approach to basic physical reality. And in fairness, I must grant that as a research program, string theory does appear to be developing in ways that are only very tenuously constrained by experiment.

    Thanks for bringing this up

    Posted August 28, 2009 at 10:43 am | Permalink
  5. Malcolm says

    Hi SD, and thanks for joining in, however belatedly.

    Posted August 28, 2009 at 11:09 am | Permalink
  6. I have read (waded through?) Smolin’s book, and though he raises some reasonable criticisms about funding of “big” physics research (somewhat repetitiously, IMHO), I don’t believe that the physics community is entirely beholden to sources of funding for choosing their research interests. The big names, like Witten (and Smolin himself), would get whatever funding they required no matter what they chose to research. Naturally, many young guns will be drawn to the Wittens and the Smolins as much as they may be influenced by funding issues.

    On the other hand, having comparative numskulls like our Congress critters deciding to abandon a major project like the SCSC, thereby enabling CERN to take the world leadership in scientific research away from the United States, at a somewhat lower energy scale dictated by the more-cramped existing tunnel for the LHC, is deplorable.

    Nevertheless, I don’t believe that even the geniuses like Witten are talented enough to succeed in a leadership role for some form of centralized allocation of research funding. Only an allocation system analogous to a free-market, which would rely on the collective wisdom of all the “players” could have a shot at an optimum allocation of available resources. You guessed it; I will NOT be joining those morons protesting against capitalism on Wall Street.

    That’s my story, and I’m sticking to it …

    Posted October 13, 2011 at 3:15 pm | Permalink