P.S. Re: [IAEP] etoys now available in Debian's non-free repository

[Dan Krejsa]

On Sat, 2008-06-28 at 04:21 -0700, Alan Kay wrote:

> It was realized that most computing of the 50s and 60s was rather like
> synthetic chemistry in which structures are built atom by atom and
> molecule by molecule. This gets more and more difficult for larger and
> more complex combinations. "Life" generally uses a process quite
> different -- instead of building cells and organisms, it grows them.
> This leads to seeming paradoxes in the epistemology of making -- i.e.
> to make a cell we need a cell., to make a chicken we need a chicken.
> However, all works fine in the epistemology of growing. But the
> initial bootstrapping is a little tricky. Once the bootstrap is done
> to make life then life can assist much more powerfully in making more
> life, and to vary life, etc. As mentioned before, the Internet is one
> of these, and so is Smalltalk.
> 
> In "biologically inspired" architectures one is much more interested
> in how the organism and ecologies of them are to be sustained, and how
> the dynamical systems can be understood, fixed, changed, evolved,
> reformulated, etc., while they are running and with the help of tools
> that work within them. Just as a cell, and especially e. g. a human
> baby, is not made by hand, we are more interested in making growth
> processes that can be influenced with far more ease than direct
> construction. So, most objects are made by other objects acting under
> conditions that include the dynamic state in which they will become
> part of the ecology.

It seems to me that this analogy is a fairly good one -- although
there are definite differences, in that the 'cell' needed to make
another 'cell' in the etoys/squeak case has been designed with lots
of tools to make it easy to inspect and modify itself, as well as
to completely sequence its DNA or produce a new generation on demand.

Living systems are however notorious for carrying historical baggage
along with them in their genotype, and, since the phenotype cannot
easily be recreated without starting with a parent phenotype, the Ken
Thompson hack implies that inheritable baggage can (paradoxically) be 
carried in the phenotype as well. I think the number of somewhat independent
tools provided to in[tro]spect a running image would make an intentional
malicious Thompson hack in Sqeak quite difficult to maintain for long
without discovery; but I would naively guess that there is some 'harmless'
baggage that looks reasonable and is allowed to continue just due to inertia.
Since the 'DNA' (source code) of etoys/squeak is readily available in a
transparent, human-understandable form, it seems to me that the only issue
of possible concern is the lesser visibility of the 'paradoxical' inheritance
via phenotype/image. Or at least, its lesser visibility if one refuses
to run etoys/squeak to use the tools it provides to inspect itself or
its images.

Continuing with the biological analogy, the folks who want to be able to
bootstrap a Squeak/etoys image (starting from 'scratch' without such an image)
want literally to be able to make ontogeny recapitulate phylogeny -- not
necessarily every time an image starts, possibly not necessarily every time
Squeak is 'built' -- but at least with similar frequency and the ease of
bootstrapping gcc using a different C compiler. (Like using a turtle egg to
hatch a dinosaur ;-)

I don't have a strong opinion on this myself, but I do find the
discussion interesting.

- Dan