Time&Eternity

160 chapter 3
evenly distributed, and the properties of the universe are invariable; the universe
is homogenous and isotropic. Within the framework of the so-called
Friedmann models, 255 which were developed with the help of this principle,
cosmologists assume that the universe came into being approximately 2 ×
10 10 years ago as a result of the so-called Big Bang. 256 According to this scenario,
a state dominated by quantum effects prevailed until approximately
10 −43 seconds after the Big Bang began (= the so-called Planck Time). At this
time (2005), there have been no theories available that can define space and
time in this state, but it seems plausible to imagine the four forces as united
in the very beginning. Then, gravity and the strong nuclear force broke away
successively from this conglomerate, until after 10 −10 seconds the electromagnetic
and weak force had also separated from each another. Via the gradual
development of quarks, protons, neutrons, and electrons, atoms emerged after
approximately 300,000 years. Among other things, the average homogeneity
of the universe and minimal fluctuations in the cosmic background
radiation, which was somewhat accidentally discovered in 1965, support the
expansion of the Big Bang model using the theory of an inflationary universe.
According to this theory, an extremely rapid expansionary phase probably
occurred between 10 −35 and 10 −30 seconds after the Big Bang.
Within the framework of the theories of relativity, the only thing that
can be said about the beginning of time is that time begins with a singularity.
257 Because a theory cannot be mathematically defined in a singularity,
this means that in terms of physics, one cannot speak of a “before” of this
singularity or of a “how” of the genesis of time. Therefore, the general theory
of relativity cannot explain the origin of space and time. “Thus, from the
theory of relativity, an internal boundary of its explanatory potential is necessarily
derived.” 258
Another singularity having significance for time that can be derived
from the general theory of relativity is that of “black holes.” 259 These occur
when a star of sufficient mass “dies” as a result of a gravitational collapse.
The gravitational field of a black hole then becomes so strong that, according
to the general theory of relativity, it “swallows” all signals coming from
the outside and does not emit any signals. According to the uncertainty
principle of quantum mechanics, however, a black hole can nevertheless
emit radiation. Hawking maintains that “black holes ain’t so black,” and he
shows that black holes can indeed emit particles and radiation. 260 What is
not possible within the framework of the general theory of relativity can be
explained using quantum-mechanical fluctuations. Quantum fluctuations
enable the emission of radiation from the strong gravitational field at the
boundary of the black hole. The energy for this comes from the black hole,
which thereby loses mass and finally disappears.