Ed Rybicki:
> > "Life (anywhere) is the phenomenon associated with th replication of
> > self-coding informational systems".
> >
James Foster:
> I'm beginning to be a devil's advocate here, using absurd arguments
> only for illustrative purposes, but...
ok, staying in the same vein.
>> Suppose you put the wiring diagram into the copier. Now the diagram
> and the copier together are a "self-coding informational system" and
> the phenomenon associated with what the machine is doing is life.
>
Perhaps it's not fully specified in Ed's definition, but it seems to
me that a `replicating, self-coding system' must include the complete
replication details, including everything to actually do the replication
--
which the copier with wiring diagram doesn't. We may also need a clause
that it be self-replicating in a specified universe, e.g. no additional
self-coding system (a human) required to come press the copy button
(although we may allow that 2 or more of the original self-coding system
are required for complete replication capabilities). Now, we could
specify a copier with the copy button held down continuously, but it's
still not able to replicate *itself*, only it's coding.
> I meant phenomena (plural) because there are several things happening
> during replication, and Ed's definition fails to distinguish any of
> them.
sure, but don't the semantics allow us to group all these things into a
single phenomenon, i.e. the very existence and functioning of such a
system ?
>> > I remember a philosophy paper in college arguing that thermostats were
> > alive: they are self regulating, have internal representations, must
> > be in a host, etc.
>> But they are not self-coding.
>> But they make the thermal properties of the house "self-coding".
but but but :-) the original claim was that the thermostat was alive,
and
this change still doesn't allow for any replication (of either the
themostat
or the house's thermal properties).
> And I've annoyed the alife "experts" before. I think that most of
Horrors ! How can you sleep at night ? :-)
>> ...I remain unconvinced that you need to define life in order to
> understand it.
Ah, but what then will we understand (as `life' remains undefined) ?
> The same is true in other disciplines. You don't need
> to define matter in order to do physics. You don't need to define
> energy in order to do chemistry. The mode of operation where you
> begin with definitions seems to work best (and perhaps only) in
> disciplines like CS and mathematics (and philosophy)...where we're
> investigating consequences of definitions.
ooops, wrong ng -- I thought this was bionet.molbio.life.philosphy :-)
rob.
--
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Robert T. Miller, Ph.D.
rmiller at sanbi.ac.za
Manager, Durban Satellite, South African National Bioinformatics
Institute
Department of Molecular Virology, University of Natal, Durban, S.
Africa
h: www.sanbi.ac.za p: +27 (0)31 2604580 f: +27 (0)31 3603744 or
2604441
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