Did it start with the "Big Bang"?
Personally, I'm skeptical about the so-called Big Bang theory and
prefer to call it a conjecture (educated guess at most). I realize of course
that there is evidence that such a phenomenon occurred (cosmic background radiation,
expansion of the universe, etc.) yet all this evidence is circumstantial. The
Big Bang has never been actually observed in any scientific experiment.
Yet, by linear extrapolation of the expansion of the universe as
measured by modern astrophysical methods there is common consent in the
scientific community that approximately 13.8 billion years ago the entire physical
universe started its existence as a tiny spot in space that violently exploded.
All physical laws, including causality which is the very basis of these laws,
came into being precisely at the moment that this enormous event occurred. Thus,
the idea that the creation of the universe was spontaneous, without any prior
cause, is not contradictory to logic. Total absence of physical rules means
total absence of impossibilities. In other words, where there are no laws,
nothing is unreasonable. Therefore the presumed spontaneous occurrence of the
Big Bang did not logically require a cause.
So why am I skeptical? Simply because the Big Bang conjecture
contradicts common sense that is based on scientific experiments and
discoveries. Why should we embrace a conjecture that our common sense rejects,
rather than pursue a more sensible explanation that complies with astrophysical
phenomena?
So, having failed to answer the first question, let me proceed to
the next.
What is this thing called Space?
Before I begin to attempt a clear comprehensive answer I want to
emphasize that by the word Space (capital S) I refer to the metric
three-dimensional space that contains the entire universe, not just to a
part of it.
We know how to measure distances and direction in Space, to specify
locations and to mathematically express all aspects of motion in it. However,
it is very difficult (I believe even impossible, at least for me) to envision
Space without any material object or at least some sort of energetic radiation
somewhere within it. That is because our vision of space is inherently coupled
with metric dimensions and angular directions in term of measurements.
Measurements are by nature comparative. Whenever a dimension or angle of
anything is measured, it is compared to the corresponding known property of a material
object or a wavelength (that is also true of other properties such as
temperature, optical, electromagnetic or chemical values, etc.). If only our
minds existed in an otherwise entirely empty Space, we couldn't perceive any
dimension or direction because we couldn't compare them to anything (just for
orientation we need the position of some object for reference, such as our nose, the three-dimensional features of
which can used to determine which direction points "forward", which points "up" and which points
"right" or whatever names we choose to call the axes of our frame of
reference. By the way, when two orthogonal directions are specified by common nomenclature,
the third is unambiguously determined, e.g. once we assert the directions of
north and up we know exactly where east is). In fact, in such a ubiquitous void
such properties would not exist, being comparative by nature. The concept of
geometric forms such as straight line, circle, cone or sphere would also be
meaningless (because the properties of any geometric form are inherently
defined in terms of distance and direction – not just formally but by their nature).
Thus, the concept of Space requires the existence of matter or at
least energetic radiation in it (not just because a living observer made up of
these constituents is required, but because the absence of matter and energy divest
Space of its inherent properties). In short, Space needs matter and/or energy
in order to exist. Obviously, matter and energy need Space just as crucially,
but that is not part of this essay.
Space also requires Time for its existence (and vice versa). In a
former essay (Time, Causality and the Relation between them) I showed
the interdependence of Time and causality for their mutual existence and
experimented mentally with the imaginary concept of a universe devoid of
causality. I explained (convincingly I hope) that the universe could not
persist for any period of time, no matter how infinitesimal, without causality.
Non-persistence for even the most infinitesimal period of time means
nonexistence. Thus, Space depends on Time for its existence.
So, now that we are convinced (at least I am) that Space needs Time
and matter in order to exist, how do we define it?
At last, a definition!
A definition is a proper answer to the question "What is
…?". By proper I mean that it conveys the meaning of the concept
defined as clearly and comprehensively as possible. I'll try to do it for Space
as best I can, within the limits of my personal understanding of the term. You
will notice that I shall admit that there are properties of Space that I don't
know to their fullest extent (I believe that nobody does).
First of all, Space is the container of the entire universe. It is
three dimensional, in the sense that we can use a three-dimensional orthogonal
axes-system (known as a Cartesian system) or, if we prefer, a triplet of polar axes or any other suitable system of
three independent mathematical entities to pinpoint locations or determine
directions in Space. It is isotropic, meaning that neither the lateral nor the angular
position of a body in Space has effect on its dimensions and form. If a stiff rod,
straight or crooked, is moved or rotated, all its geometric properties (length,
thickness, curvature, roundness etc.) are maintained – assuming of course that
they are not affected by external forces. Isotropy of Space also means that,
without an external physical entity for reference (such as a viewable object, a
source of sound, a gravitational or magnetic field, etc.) we cannot have the
slightest idea about our location and orientation. That is because all physical
laws that act on any object in Space do not depend on our position in Space.
We also know that there are some properties erroneously attributed
by some people to Space, such as angular orientation, linear and angular motion
(these properties are relative by nature, and cannot be attributed to Space
because there is no reference to which they can be compared) or physical
properties that material objects have.
Oops, haven't finished! Seems there is more to be said!
So far so good, but Space has other properties too, some of which
are to this day an unsolved mystery or at most under scholarly debate. Does it
somehow extend beyond the limits of the universe? Is it really expanding or oscillating? Is it
enveloped by a spherical or other-shaped boundary or is it infinite? Does it
have a distinct center? Is it continuous or discrete? How is it affected by the
laws of relativity (both special and general) and quantum physics? Is it unique
or a subsystem of an esoteric hyperspace? Can it split into multiple spaces that
cannot interact with each other? Why is metric Space three dimensional and not,
for example, four-dimensional? I assume there might be other questions that
have so far been left unanswered.
I don't have a definite answer to any of these questions and I
doubt that anybody in the World does. However, prominent scientists do have
their opinions on at least some of these issues, backed by experimental
evidence, analysis, logic and common sense. I also have an opinion on these
issues that is based on ideas that I have heard, read, learned or arrived at by
thoughts that occupied my mind.
First of all, the relation between the boundaries of Space to those
of the universe is a semantic issue. As far as I know, all serious scientists
regard Space as the locus of the universe in its entirety. If the universe is
finite, Space does not extend beyond it and there are no physical rules beyond
it. That's unimaginable, but otherwise either the universe is infinite (hard to
imagine) or closes upon itself in a three-dimensional analogy to a closed
circle within a four-dimensional hyperspace (such an idea has been seriously
proposed by scientists but at least for me it is totally beyond imagination).
Most physicists and astrophysicists believe that the universe (and thus Space)
is finite and expanding.
Some scientists toy with the idea that the universe is oscillating,
at present in the phase of expansion in a periodic cycle which will eventually
pass to a phase of contraction. That's a weird idea because it defies the rule
of increasing entropy (if you don't know what entropy means, just take my word
for it), which apparently means that causality is reversed. If that is not
sheer nonsense, I don't know what sheer nonsense is.
Most scientists today believe that the boundaries of Space are
continuously pushed out by the radial expansion of the presence of matter (and
perhaps antimatter) and radiated energy. Physical laws are carried outward up
to those boundaries in unison with this expansion. Nothing exists beyond those
boundaries, not even empty space, and thus physical rules do not extend beyond
those boundaries. Even the phrase "beyond those boundaries" is
meaningless, unimaginably as it sounds. Are these boundaries spherical? My
answer to this and to the question about whether Space has a distinct center
is: "Who knows? Who cares?" Hopefully I'm not offending anybody. I
can assure you that our planet is at a safe distance from the nearest point on the
boundaries of Space, if such exist, by at
least thousands of light years (probably much more).
Is Space continuous or discrete? I mean Space, not the universe
(which is not synonymous to Space). Well, from the point of view of classical
physics, discreteness means that the points that constitute Space are separated
by gaps. If that were the case, the metric dimensions of each Space point would
each have a value that we may call "the elementary unit of length in nature"
and nothing material, wavy or void could be smaller. Even if that were a valid
possibility, we still have gaps of this model to consider. If they are
microscopic regions of empty space (just gaps in the universe) then they are
still included in the regions that constitute Space and therefore are not gaps
as far as Space is concerned. If they are true gaps in Space then they are
dimensionless, meaning that distance measurements that pass through them do not
skip any metric lengths and are therefore continuous. So, in any case,
classical physics rules out discreteness in Space.
Special relativity deals with differences in time durations, metric
lengths, masses and all other material properties related to them as measured
in frames of references that move relatively to each other. To my best
knowledge, these differences do not affect the continuity or discreteness of
Space, whichever is true. As far as I know, neither does general relativity, my
knowledge of which is limited to popular scientific publications. What remains is
quantum theory with its Heisenberg principle of uncertainty according to which
the exact location of every elementary particle is inherently somewhat vague,
with a precision that is inversely proportional to the precision we have of its
momentum. Quantum theory also deals with discrete values of energy, spin and
other properties of elementary particles when they interact with other
particles inside atoms. I'm far from being an expert on the subject but I've never heard
or read of any effect that quantum theory has on the properties of Space
itself, so I conclude that as far as I know, Space must be continuous.
My next two questions, whether Space is unique or part of an esoteric
hyperspace and whether it can be split into multiple spaces, sound perhaps like
referring to science fiction. However, renowned scientists regard these questions seriously.
None has come up with an answer, not even a clue except some conjectures about
black holes being portals to other universes (reminds me of Costigan's
Needle, a science fiction book I read decades ago). I believe that it
is absolutely impossible to either prove or refute these issues.
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The assumption that multiple spaces exist raises at least four possibilities:
1.
All spaces exist in mutually disjoint locations in a common three
dimensional container - OR
2.
Each space has its exclusive set of
three dimensions, completely dissociated from those of its peers - OR
3.
All spaces exist along disjoint "time" axes - OR
4.
All spaces share the same time axis, their metric properties might
coincide or overlap with different boundaries, but all the "material"
and "energetic" constituents as
well as all natural rules in each space cannot interact in any way with those
of the other spaces.
The first model seems to me least likely for the following two
reasons. First, it implies
null-dimensional gaps that in turn implies
that the spaces are completely crammed together. That is plausible only for a
limited set of polyhedra (assuming that all spaces are of the same form) or a
weird collection of convex and concave forms. Second, it implies metric
continuity at the boundaries unifying all spaces into one.
The second and third models seem to be abstract ideas. I think they
are both beautiful, baffling, esoteric, a challenge to inquisitive minds.
Abstract I said? I have examples that I'm sure that anyone who reads this can
understand, because undoubtedly everyone has experienced them. One of them is
fiction, the other is dreams (including daydreaming). In both examples, our
mind is exposed to an imaginary ambiance with metric and temporal features same
as those we have in "true life". (I admit that these examples are not
perfect, because their features are affected by those of the "real
world", however once they have been created there is no further interaction).
OK, you may say, but they are imaginary. So what if they are just imaginary,
whereas our Space is real? What does "real" mean? If multiple spaces
exist, is our Space real and the others imaginary? Objectively, all spaces
should be of equal standing, so that if the others are imaginary, so is ours.
Furthermore, there are philosophers who propose that our existence is imaginary,
a thought experiment of a mind somewhere out there in hyperspace.
The fourth model actually proposes multiple universes residing in
one common space, except that they might perhaps have different boundaries
(beyond which the physical laws of the corresponding spaces do not exist). Such
a notion might challenge scientists to seek signs of the existence of so far
unknown forms of pseudo-matter or pseudo-energy that would, under special
laboratory conditions, emerge to the surface and hopefully not swallow us all.
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The last question I brought up was why does Space only have three
dimensions. Before I continue I suggest that if you are not acquainted with
vector analysis or have forgotten what you learned in college years ago, read a concise and very clearly written tutorial explaining Elementary
Vector Analysis on the Web. It should suffice to understand the
following answer to the question, but if you wish to obtain more information
you can of course google for more advanced texts on the subject.
The shortest answer I can think of to the question above is that
mathematically, a metric isotropic space cannot have more than three dimensions.
That is because Space must have geometric properties that can be represented by
an orthogonal coordinate system. According to the rules of vector analysis, the
cross product of any two orthogonal unit vectors in a three dimensional system yields
a unit vector normal to their common plane. There cannot be an analogous
relationship between the constituents (unit vectors or unit planes or whatever)
of a higher dimensional coordinate system. So, there go any prospects you may
have for a four-dimensional metric space. Of course, Time is referred to as the
fourth dimension in scientific parlance, but evidently it is not metric.
Just a few more words
That's all for now. The short account that I intended to write of
my thoughts about Space blew up as in a Big Bang and if I don't stop now who
knows how far its boundaries will be pushed out, so, to conclude I would like
to beseech the Almighty if He (or She) is behind the creation of the universe:
"Please stop expanding our boundaries, at least for a while. We are very curious to know what
lies beyond them but we just can't keep up with your pace!"
