COSMOLOGY
It
is often pointed out that if we run the universe in reverse to a time near the
big bang that the density of the universe must have been greater than that
required to form a black hole, so how did the universe manage to expand to what
we see now? The standard response is to say that the universe is infinite and
even at the time of the big bang the universe was already infinite and not
confined to a small volume. The flaw in this response is that current
cosmological measurements of the omega factor indicate that omega is greater
than one and therefore closed, with spherical curvature and finite volume. The
argument that the mass of the universe is infinite requires the Omega factor to
be exactly unity and although that is not completely ruled out, the indications
are that the universe is closed and finite. A closed and finite universe has to
explain why the early universe did not simply collapse to a point of infinite
density and the current accepted physical interpretation of black holes can not
do that. In this new physical interpretation of black hole physics, collapse to
a point of zero volume and infinite density is impossible. The force of gravity
as mass is compressed towards zero volume approaches infinite in the outwards
direction. The outward acceleration can be many orders of magnitude greater
than the speed of light and thus the new interpretation allows rapid inflation
of the early universe to be a natural consequence of General Relativity. The
new interpretation provides a natural mechanism to rebound a collapsing
universe preventing its total collapse. This admits the possibility of a cyclic
universe once the issues of thermodynamics have been resolved, perhaps by
studying the relationship between thermal and gravitational entropy*. Of course
there are still other issues to be resolved, such as the problem presented by
Birkhoff’s theorem and how the new interpretation impinges on the Friedmann-Lemaître-Robertson-Walker metric. Clearly there
are implications to cosmology introduced by the new physical interpretation,
but exactly what they are is not clear at this point. This would be an
interesting topic for further research.
*Entropy
In
determining time’s
arrow, the second law of thermodynamics predicts that the evolution from state
1 to state 2 is the most likely outcome. This would be correct for a small
cloud of hot gas particles. However if we were considering a very large cloud,
then gravitational collapse would make the evolution from state 2 to state 1
the most likely outcome.
So
evolution from state 1 to state 2 is example of increasing entropy but so is
the evolution from state 2 to state 1 an example of increasing entropy. This suggests
that gravitational entropy works in the opposite sense to thermal entropy and
the total entropy remains constant, even though thermal entropy is being
converted into gravitational entropy or vice versa.
This
is similar to the conversion of kinetic energy to potential energy. A swinging
pendulum is an example of a cyclic process where kinetic energy is continuously
converted to potential energy and vice versa while (in a perfectly frictionless
system) the total energy of the system remains constant. The interchange can be
dynamic and everlasting in a perfectly enclosed system which the universe as
whole probably is.
Now
if we take a freeze frame photograph of the swinging pendulum, it is not easy
to tell if the weight is on its way up or on its way down. In a perfectly
frictionless system the second law of thermodynamics tells us nothing about the
arrow of time for the pendulum and which way it is going to swing next and yet
clearly if there is motion then there is a direction for time. One way to try
and guess its future direction is to look closely at the motion blur of the
pendulum weight in the photograph. This is the clue to the arrow of time in a
perfectly reversible dynamic system.
The
present ‘now’ is inextricably linked in a ‘fuzzy’ way to the infinitesimal
past, and it is the infinitesimal past of the present that determines the
infinitesimal future of the present. We can observe that no matter how short
the exposure time, we can never capture a photograph with no blur, for to do so
requires an exposure time of zero and nothing is
observed. The concept of an instant of time where we mean an interval of
exactly zero time has no physical meaning. Time is not a sequence of static
‘frames’. This point of view is supported by the Heisenberg uncertainty
principle. The more precisely we try and pinpoint the location of a particle
the greater the uncertainty of its velocity and vice versa. An ‘instant of
time’ is a therefore an interval that overlaps the present with the immediate
past. It is this principle that allows our minds to have an intuitive sense of
time and motion and past and future which would not be possible with a sequence
of static instantaneous ‘nows’.
Another
example is the interchange of mass and pure energy. The total energy of the
system never changes. Is it possible that entropy has interchangeable forms,
like energy, while the total entropy of the universe remains constant? The
perfect pendulum example shows that it is possible to have motion without
requiring the system to have an arrow of time defined by increasing thermal
entropy. This is known as a reversible system. If we admit this possibility of
total entropy being an invariant quantity made up of thermal and gravitational
entropy, then the universe does not have to be a one way trip to an inevitable
heat death, but can be a everlasting, dynamic cyclic
system.
Hawking
Radiation and the “information loss paradox.”
In
the section on the formation and evolution of a black hole it was suggested
that matter originally within the Schwarzschild radius of a collapsing star
moves outwards to form a shell of material asymptotically approaching r=2m from
the inside and a corresponding shell of matter is asymptotically approaching
r=2m from the outside forming two concentric shells near the Schwarzschild
radius. Since the outer shell is comprised of real particles, they will radiate
due to chemical, thermal, synchrotron and nuclear processes like any normal
matter, except that the radiation will be extremely time dilated and red
shifted. To an outside observer this red shifted radiation will appear as Hawking
radiation, but no exotic explanation involving virtual particles or holograms
is required to explain its presence. If the mass is not continually added to
the black hole this radiation causes a net loss of mass from the black hole and
the zero time horizon recedes releasing particles trapped in the inner shell,
into the outer shell. By this process the particles that created the black hole
can be released and no information is lost and so the “information loss
paradox” that has been a fundamental problem of black holes is shown to be a
non-paradox.
See
http://en.wikipedia.org/wiki/Black_hole_information_paradox
Reconciling
Quantum gravity with General Relativity.
So
far all attempts to get quantum gravity theories to agree with General
Relativity have met with failure and to date there is no accepted theory of
quantum gravity. The argument presented here, is that if General Relativity has
been wrongly physically interpreted then no correct theory of quantum gravity
has any hope of agreeing with it. Imagine some researcher who is on the right
track with a quantum theory of gravity and his or her theory predicts that
beyond a critical density that gravity becomes repulsive. Since this is at odds
with classical interpretation of General Relativity that correct theory of
quantum gravity would be rejected and reformulated to try and agree with the
incorrect classical interpretation of General Relativity. That would obviously
be a fruitless activity and inevitably lead to dead ends. (Sound familiar?) Any
correct quantum gravity theory should show that a singularity of infinite mass
density can not form, that time reverses and gravity become repulsive when mass
density exceeds a critical value and that for a vacuum solution the proper time
of a falling particle below the event horizon is imaginary and that real proper
time for a particle in the same region is unphysical. Now that the target has
been corrected and clearly identified there might be some possibility of a
quantum gravity theory hitting it.
©
2008 KevPegrume