Time&Eternity

Time in the Formulation of Scientific Theory 167
denotes the measure of disorder in a system. In everyday life, we experience
entropy in many ways: Hot coffee cools off at room temperature; it has not
yet been observed that milk poured into coffee spontaneously separates out
again after dispersing, although according to the laws of classical mechanics,
this must be possible. These observations create enigmas. How can it be
that coffee and milk follow a temporal sense of direction although the laws
that determine the behavior of coffee and milk molecules are time-symmetric?
283
But it is not only the domestic coffee table that obeys the Second Law;
even our solar system continually complies with it. The sun is slowly burning
its nuclear energy; it will radiate light and warmth until its collapse in
approximately five billion years, and thus, with every photon emitted, it increases
entropy in the universe. Applied to the universe as a whole, the theorem
of ever-increasing entropy therefore means that the order in the universe
is moving toward decay. In this context, one frequently speaks of the inevitable
heat death of the universe. This does not mean that the universe is
being destroyed by heat. Nor does it mean directly that the heat is disappearing
and extreme cold will rule. What is “dying” is the exchange of energy, so
that ultimately there will no longer be a gradient between different levels of
energy. Heat death thus signifies complete heat equalization (thermal equilibrium)
and maximum disorder. A state has been reached where time has
ceased to flow. This is why thermal balance is also called a “time peak” [Zeitgipfel]
284 At the time peak, an isolated system is cut off from a possible future
because it can no longer change. It also no longer has access to its past, for
the development cannot be directed backwards by the decrease in entropy.
For the first time, something like a historical dimension becomes visible in
physics itself. 285 The irreversibility in thermodynamics invites one to rethink
the relationship of being and becoming. For Newton it was reasonable to
understand the universe as a pattern of eternally existing elements. Thermodynamics,
on the contrary, urges one to understand becoming as the basic
structure of the universe.
Because of the insights in thermodynamics, a modification of the concept
of the universe was called for. The view of the universe as a perfect machine
as found in Newtonian physics is no longer tenable. The conception
of a uniform and, in principle, infinite universe was replaced by the concept
of the universe as a heat engine that ultimately destroys itself: no longer an
eternal machine, but, rather, a programmed apocalypse.
Here, one may feel compelled to object. How can the Second Law claim
absolute validity when, at the same time, we can so often observe an increase
in order and a development of higher complexity? Is there not an irreconcilable
conflict between thermodynamics and the principle of evolution?