From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Wed, 30 Jul 2008 08:35:22 -0700
From: "Roman V. Shaposhnik" <rvs@sun.com>
In-reply-to: <14ec7b180807300700j58f73002g7afa2dba3da0fc49@mail.gmail.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
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	<14ec7b180807300700j58f73002g7afa2dba3da0fc49@mail.gmail.com>
Subject: Re: [9fans] current state of thread programming
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[I promise this to be my last off-topic message, but I just can't resit]

On Wed, 2008-07-30 at 08:00 -0600, andrey mirtchovski wrote:
> So, in essence, I think the brain may be exactly what Dijkstra had in
> mind in the earlier quote: its workings are so implicitly parallel
> that the word 'parallel' carries no meaning when describing it.

I believe I've already bored everyone to death with this joke (I usually
tell it during my Multicore and Transactional Memory presentations),
but here it goes again. If we were to oversimplify things than brain
is, at its core, limited by a very fundamental biological constraint:
speed at which cells can communicate. A sort of "propagation delay"
if we were to use electronics as an analogy. It seems to be agreed
upon(*) that we can safely assume this constraint to limit our brain
to about couple of hundred of processing steps per second. This is
known as a "100 steps rule". Something is really, really wrong with
the computing model we base our technology on, if even the slowest
of the computers we can consider useful required a clock rate
of KHz.

I really wish Jeff Hawkins (http://www.onintelligence.org/) the best
of luck. I doubt his institution is going to unlock the mystery
of the brain any time soon, but the feedback for our industry
can be pretty groundbreaking. If they get lucky, of course.

Thanks,
Roman.

(*) Rumelhart, E., & McClelland, J. L. (Eds.). (1986).
    Parallel Distributed Processing. (Vol. 1, 2).
    Cambridge, MA: MIT Press.
    --------------------------------------------------
    Feldman, J. and Ballard, D. (1982),
    Connectionist Models and Their Properties
    in Cognitive Science, 6, pp. 205-254.