><snip>
>Richard
>I think that, if we strip away the misleading talk of "code-driven
>energy-conversion systems" and processes "overcoming" the Second Law, what
>the objectors are really asking is this: what is the process by which
>energy (e.g. from the Sun) drives a decrease in entropy in pre-biotic
>structures?
>
>As far as I can see, this question is not directly related to the Second
>Law. I suppose it's indirectly related, because it concerns thermodynamic
>entropy.
>
>I think the short answer to the question is "through chemical reactions (and
>possibly other physical processes) which require heat." Without heat, the
>chemical reactions could not take place. Of course, this doesn't just apply
>to prebiotic structures. There are all sorts of inorganic structures whose
>entropy decrease is driven (directly or indirectly) by heat. Commonly cited
>examples are snowflakes, crystals and tornados. But they can also simply be
>molecules undergoing chemical reactions to form lower-entropy compounds. If
>these can experience decreases in entropy without a "code-driven
>energy-conversion system", then obviously pre-biotic structures
>can do so too.
>
>I hope David will correct me if I've got anything wrong here. Sorry, David,
>but I hope you won't consider it a waste of time to educate me. ;-)
Chris
I would replace "heat" with "energy" in the paragraph above, since many
chemical reactions are driven by energy other than heat, such as specific
frequencies of light energy. Photosynthesis, for example, will not occur
just by the application of heat; it requires light. Electrical energy, such
as from lightning, can also drive chemical reactions.
Since reproduction can occur either as a mere catalytic process, a
template-using process, or as a process of creation and assembly of
components (as in virus replication), there are plenty of ways in which the
Sun's energy, and the energy from the core of the Earth itself, etc., can
promote reproduction once this energy has brought about enough natural
"mixing" of existing components to produce the first simple and suitable
replicator. Once that replicator exists in a suitable environment, it will
proceed to "saturate" that environment, unless it first produces fitter
variations. Saturation yields serious selection: From this point on, the
molecules that dominate will be the ones that are best at getting
reproduced in the crowded environment with limited resources out of which
new copies of themselves can be made. At this point, opportunities for
predation become important, as do variations that can take advantage of
otherwise unused factors in the environment, such as other substances and
other sources of energy.
Further, since even the simplest catalytic process is "code-driven," there
is also no lack of code-driven processes, though this is, as someone
pointed out, in *addition* to having an energy source.
All chemical reactions are ways of allowing energy to travel "toward"
equilibrium. The energy bound up in a molecule produced by the application
of energy from outside the vicinity is closer to the equilibrium level than
it was before it contributed to the production of the molecule. It will go
still closer to equilibrium when it is released later. Replicators are a
fairly good way to allow energy to pass "through" the biosphere (in and
then out) on the from the Sun and the Earth's core to open space. This is
because they use up energy in reproducing, and, if they evolve the ability
to actively *use* energy, if (in other words) they *live*, they use it up
in the process of living. Thus, living things are one of the ways the Earth
has developed to dissipate energy from itself and from the Sun (and from
the Moon's tidal effects).
Since life itself is a pathway for energy flowing toward equilibrium, life
*depends* on the Second Law (or, more nearly exactly, on the facts that we
describe by means of the Second Law). If the entire Universe were already
*at* "heat death" equilibrium, there would be no life at all in it, because
there would be no "available" energy for it to use.
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