Tuesday, February 15, 2011

A simple handwave that makes The Matrix tolerable for the scientifically literate

Suppose that controlled fusion power requires real-time control computations which can be much more efficiently implemented in neurological hardware than in silicon.

(That Second Law of Thermodynamics thing was bothering the hell out of you, wasn't it?)

Note that neurological hardware really is exceptionally power-efficient for certain classes of computations. Common estimates of the human brain's power consumption are 20-25 watts; this is roughly the wattage of a Mobile Intel Core i5 processor, which (as far as we know) appears to be a much less powerful computer for many purposes. By contrast Watson runs on 90 IBM Power750 servers, filling ten racks, whose power draw is something like 80 kilowatts. In other words, Watson consumed about four thousand times more power than either of its meat-based competitors.

Here in reality, I think it's unlikely that any fixed class of computations can be efficiently implemented in neurons but not in silicon — see Carver Mead and his academic descendants' work on analog silicon circuits. But positing that such computations may exist seems within the realm of acceptable science-fictional handwaving.

UPDATE: Yes this is close to the standard handwave that the humans are being kept as computing devices, not power sources. But I think you need to draw the connection explicitly to power generation; otherwise there's just too much narrative in the film and animated shorts that makes no sense.

UPDATE': Never mind, I just remembered Morpheus's exact wording from the first film's voice over and I don't think it's salvageable. Oh well.


  1. What did Morpheus say? I like your theory -- just because it's interesting -- but it would require me to believe that said real-time control computations exactly mimicked our brain function in day-to-day life in the Matrix. Or else I suppose they use some other, as-yet untapped part of the brain...

    My memories of the movies are hazy, but I always imagined that the machines evolved to rely on a very refined power source, say the alpha and beta brain waves produced by humans, for which there was no cheap mechanically-reproducible alternative.

    Anyway, unquestionably the weakest foundation of the movie.

  2. besides, the people in the matrix are leading "normal" lives. so they are presumably using all their processing power to move around their virtual worlds, think about their petty little personal lives, etc. where's the spare processing power? unless there's some seriously awesome alien programming that can produce human thought and competency as a SIDE EFFECT of whatever computations they were actually after?

  3. aj: Finally dug out my Matrix DVD so I could get Morpheus's exact wording:

    "The human body generates more bioelectricity than a 120 volt battery and over 25 thousand BTUs of body heat. Combined with a form of fusion..."


    Anyway, leaving that aside, assume that the Matrix is somehow actually more boring than a real 21th century world would be. This accounts for the pervasive feeling of some individuals that there's something unfulfilling and empty about their existence. Conveniently, running this hollowed-out world on a brain allows the majority of its processing capacity to be dedicated to other uses.