THE SOUTHWORTH PLANETARIUM




*207-780-4249 <207-780-4249>       www.usm.maine.edu/planet
<http://www.usm.maine.edu/planet> 70 Falmouth Street  Portland, Maine 04103
43.6667° N,                    70.2667° W Founded January 1970*
                      * "Keeping a watchful eye on a complex sky"*

THE DAILY ASTRONOMER
Tuesday, April 12, 2016
The Middle of Nothing





The problem many encounter when contemplating the Big Bang is its origin
point.   Where in the Universe did the explosion occur and how far is our
solar system from this cosmic ground zero?   Such a question seems logical,
but is actually unanswerable and therefore problematic.  It is not merely
that the question extends beyond our scope and eventually some clever
descendant will discover an answer.      Instead, the question, itself, is
predicated on a misconception: that the Big Bang is analagous to a
conventional explosion happening at a discrete spatial point and expanding
radially away from it.  That one should envisage the Big Bang this way is
understandable, since we constantly refer to it as the most powerful
explosion ever.    Consider that description poetic license if not accurate
science.



Big Bang science, properly called "cosmology," begins with sheer
ignorance.    Scientists don't know what transpired at the precise "birth"
moment because the models tell us the Universe was born from a singularity:
a mathematical point of no dimension.       Though quite powerful,
theoretical physics is confounded by singularities, just as mathematics
goes off the rails when someone tries to divide by zero.    Our inability
to understand the conditions within a single point -since the term "within
a singularity" is meaningless- precludes us from knowing what happened at
time zero.      Physical models begin at something called the "Planck
Wall," which is 0.000000000000000000000000000000000000000001 second after
the Big Bang event.     This time span is the ultimate eye blink, but is
not the same as the initial moment.



Though cosmologists are still ironing out the details, the Big Bang theory
tells us that the Universe has expanded since formation and is currently
expanding.    The initial theory assumed the Universal expansion would
decelerate with time as the matter exerted a gravitational retarding force
on it.    Within the last fifteen years, however, astronomers have
discovered that the Universal expansion is accelerating!   As they have not
yet identified the force responsible for this propulsion, they've ascribed
it to 'dark energy,' a mysterious impulse that likely pervades the
Universe, but eludes detection.    We know of it only because of its effect
on what we can observe: the receding galaxies.



It is possible that the cosmos will expand forever; that ours is an eternal
Universe destined to become increasingly more rarefied as the matter within
it disperses.   Until we learn more about dark energy, any presumption
about our Universe's fate will be speculative.   What we do know (or
believe we know) is that we were all born out of nothingness.   Time,
space, matter and energy all took form once the Big Bang singularity
unfurled the Universe we inhabit today.



All things: the galaxies within the Hercules supercluster; all the planets
within all the galaxies; the Moon; Earth and all the material within it and
around it; and every little speck within every little nook were once
confined within a negligibly  small volume that ballooned out into the
Universe.        There is neither middle nor edge anymore than there is
before or after or outside.       Our space-time system is self contained*
and any such spatially or temporally relative terms are sensible only when
applied to regions within the Universe.



We cannot define the starting point because it is everywhere.   You are in
the middle of the Universe.  Then again, so, too are the phosphorescent
ferns tucked away on a planet in the Horologium Supercluster.





*Of course, ours might be just one Universe of many. The notion of multiple
Universes, once the sole reserve of science fiction writers, is physically
feasible, although we're damned if we know how to prove the existence of
other such universes.  They are theoretical constructs; but, then again,
from the perspective of beings in an alternate Universe, so are we.     The
more one tries to explain the nature, the stranger it becomes.