Re: teaching evolution in Wisconsin
Wed, 6 Oct 1999 16:38:05 -0400


>>>I suggest that in the absence of a designer (and maintainer) that the
>>>entropy of living systems would increase, rather than complexity and order
>>>increasing together.

I suggest that the absence of a designer/maintainer/creator/sustainer is
incomprehensible. Without such a presence I see no reason for why
anything or any laws of nature should exist one way or another in any
particular form. Without such an enforcer/realizer of the laws of nature,
what criteria ought we use in evaluating how things would/could be
different? Anything goes and nothing goes. It seems to me that such a
presence is a prerequisite for the actualization of any concept of nature
at all. Just because our formulations of the laws which describe the
workings of the physical/natural world make no *explicit* reference to
such a presence, that is no reason to think such laws would also obtain
and continue to be upheld and enforced in the absense of such a presence.
Neither is it a reason to suppose that there would be any natural world to
so describe anyway.

>>the energy from the sun decreases entropy locally on this planet. When the
>>sun dies, entropy resumes.

The energy from the sun maintains a disequilibrium on the earth's surface
because the temperature in the direction of the sun is some 5780 K while
the temperature in most of the other surrounding directions around the
earth is close to 3 K. This temperature imbalance w.r.t. the earth's
surroundings maintains a net throughput of energy from the sun into the
terrestrial surface and back out to the cold darkness of outer space.
This disequilibrium allows the formation of a host of various terrestrial
dissipative structures which locally act in coordinated, organized,
complicated, and ordered ways. These mechanisms operate in a way so that
the total entropy of the earth, to first order, remains *constant*, but
this constant value is made up of a sum of many time-dependent
contributions from the parts of the earth's surface which are
participating in the operation of those dissipative structures which are
fluctuating up and down significantly as those processes operate.

As I recall, when the sun ends its main sequence life it is expected to
become a red giant and swell out to a radius which would devour both
Mercury and Venus and almost reach the earth's orbit. As it swells the
temperature of the outer reaches of the sun would fall and stabilize at
an orange-red hot temperature of around 3000 K (about half its current
surface temperature). At such a time the earth's temperature would sky
rocket (to a value much higher than consistent with any forseeable form
of life) causing the earth to, at least, loose all its volitile near-
surface substances leaving behind, at most, a cinder or a molten mass of
rock. At this time the entropy of the earth, assuming it continues to
remain essentially intact, would be significantly higher than it is now.
Once the solar red giant phase ends then the remnant of the earth would
cool down *very* much as the remnant of the sun (after it expells its
outer layers as a planetary nebula) collapses down to a white dwarf. The
frigid remnant earth would have a much *lower* entropy than it now has.
Thus, after the sun dies entropy does not "resume" (whatever that means).

>>Or perhaps that mysterious designer might choose
>>to withdraw at the same moment. How would we tell the difference?

There's no telling what to expect.

>The sun is shining on Venus as well. A question: is entropy there also
>decreasing? Or is it increasing? Or staying about the same?

As of now the total entropy of Venus is (like Earth) keeping fairly
constant. Once Venus is vaporized and incorporated into the bulk matter
of the sun in its red giant phase, its contribution to the entropy of the
sun would be much greater than its current entropy value. The final
entropy of the matter of Venus depends on whether that matter is mostly
expelled from the sun when it expells and forms an expected planetary
nebula at the close of its red giant life, or whether it remains behind in
the solar core that ultimately collapses into a white dwarf.

David Bowman