Mitch writes
>> It's possible that more advanced civilizations try
>> to achieve reversibility. It might be kind of an
>> "ecologically" or "environmentally" friendly way to
>> calculate. Primitive civilizations, like ours, might
>> be forgiven for charging ahead irreversibly. >>
>We could be forgiven then for being a slash and burn
>culture-not even at Kardashev1 yet!
Yes. But I really shouldn't have phrased it this way for several reasons.
One is that we are probably alone in the visible universe. But more
importantly, what I was getting at is this: suppose that in the long run
entropy really is the enemy. Then thousands of years from now it may
behoove us to become reversible. Reversible calculations, of course, do
not increase entropy. Yet intelligence and a continually developing
civilization would not be compromised. (A nice problem, which I think
that I know the answer to, is, "are conscious reversible Turing machines
also conscious when run backwards?") By becoming reversible, our
civilization might lenghten its total life span, if Dyson and
Tipler turn out to be wrong about the universe sustaining infinite
computation.
I have not been entirely successful in resolving the relationship
between life and entropy (perhaps some here can help). We say
thermodynamically that the energy generated by the sun (which
drives almost everything else in the solar system) is finally
dissipated to deep space, and stops off only briefly on Earth.
Here (and soon throughout the solar system) it supports the creation
of ordered structures. So at first glance, life and entropy might
seem unrelated (given the final entropy production between the sun
and deep space). Yet the non-trivial amounts of order created on
Earth may have to be included in the equation.
Consider the shadow on the distant stars the Earth makes. It's
easy to see that life on Earth may accomplish energy storage,
so why not neg-entropy storage?
Certainly the energy storage of prehistoric times (mostly in oil
I would think) is currently being used for the creation of highly
ordered artifacts in the human sphere (or noosphere of de Chardin,
I suppose that we should confess). Coming up shortly will be
massive energy expenditures in fusion and fission, which are
star power rather than sun power. But on the whole, (a) has life
lessened the overall entropy production? (b) is man's present
and future enormous energy consumption, which will be used to
create even more order, hastening or hindering entropy production
in the solar system?
Lee
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