The basic constants of nature, the physical constants, are the building blocks of which the universe is made. They are basic; they cannot be expressed in terms of other constants. There are half a dozen in all: the force of gravity, the speed of light in vaccuum, the masses of the elementary articles, the strength of electricity and magnetism and Planck’s Constant, and, according to prevailing theory they emerged in the first fraction of a second of the Big Bang, when they achieved the values and properties they have today. One of the mysteries about them is why they got exactly the values they do have. We shall get back to that later, but I should mention that in string theory (q.v.) the physical constants no longer possess fixed, arbitrary values. They occur in a mode similar to electromagnetic fields.
Classical physics (Newton, Maxwell) was founded on firm beliefs which were based on everyday experience and could be described in everyday language. One of the most important was that all physical processes were unambiguous, so that it ought in principle to be possible to calculate the state of a system at any randomly selected later moment in time on the basis of knowledge of all the factors - their positions and their velocities – acting on a body in the system. At the same time this deterministic or causality picture presumed the possibility of objective observation, i.e. that the observer had no effect on the result of the observations.
The fact that certain phenomena in the field of thermodynamics
could provide more precise knowledge of individual phenomena by refining the
experimental set-up made it possible to gain more precise knowledge of
individual phenomena such as the movement of individual molecules, making it
necessary to apply statistical methods of calculation. The good agreement
between theory and practise gave no grounds for doubt in this respect.
Another important tenet was that Euclidean geometry applied
throughout space, for instance that the sum of the angles inside a straight
sided triangle would always add up to 180 degrees.
Newtonian physics also postulated that the weight of a body would
always be equal to its inert mass, and that for observers moving relatively to
one another their measured velocities (for instance that of light) were
different.
All these assumptions are intuitively understandable to the
observant layman, so there was close correlation between ordinary speech and
scientific parlance. But with Einstein’s theories, the development of quantum
mechanics, and Niels Bohr’s complementarity theory, they started to be
scrutinized one by one. Let us look into the theory which forever changed the
way in which we view space and time.
In
1905, Einstein published his Special Theory of Relativity. In it, he said
that no particular object in the universe has a privileged position in the sense
of being at rest with respect to space. Consequently, either one of two
observers, moving relative to one another, may claim that he is at rest
while the other must be moving. He is equally correct in referring any motion to
his own frame of reference. The revolutionary thing was his statement that
measurement of the speed of light would always give the same result, whether the
observer moved with or against the beam of light, irrespective of his own speed
and of whether the light was emitted from his own or from another frame of
reference. The other observer will find the speed of the beam emitted by the
first observer to be identical, even if they were moving at extremely high speed
relative to one another.
This
invariance of the speed of light found only one explanation: relativistic
transformation. It implies that an object in motion contracts in the
direction of movement, its mass increases, its physical processes slow down, and
its time, as clocked by an observer at rest relative to the moving
object, slows down. It was this last claim that shocked the scientific world,
implying as it did that movement was able to influence the progress of time!
Einstein
also postulated that two observers moving relative to one another at a constant
speed would observe identical laws of nature irrespective of the distance
between them. This is called the general covariance principle. Furthermore,
he
showed that two spatially separated events deemed to occur simultaneously by one
observer might occur at different moments viewed from another. Simultaneity
between them cannot be established, and they cannot agree on what Now means.
Each observers’ Now is as good as the other’s, so in Einstein’s universe,
there can be no common past, present and future. The
relationship between distant events can only be worked out by entering both
events’ space- and time coordinates in the so-called equations of
transformation. This fact
is known as the relativity of simultaneity. Space
and time thus become intertwined in The space-time continuum.
In
1916, Einstein published his General Theory of Relativity. While his special
theory deals with objects moving relative to one another at constant speed, the
General Theory offered a new explanation for gravity. Einstein postulated the principle
of equivalence between gravity and acceleration, stating that in principle
it was impossible to discern between the forces of gravity and acceleration by
experiment. Indeed, he claimed that Newton’s law of gravitation was
unnecessary. Wherever gravity was at work, it could equally well be claimed that
the object in question was accelerating, but in four-dimensional space-time. He
generalized this by stating that space is curved near massive objects. Einstein
eliminated the best-known force: gravity, and thereby doing away with an
antropomorphic, mystical force, equating it with the metric capacity of space
and thus substituting it with non-Euclidian geometry.
Relativity
is not just mathematical abstractions. It has stood its test in multiple
scientific experiments. But it also puts its daily mark on the “real” world.
The satellites of the Global Positioning System (GPS) must maintain an
incredibly high standard of precision so as not to mislead users on the Earth or
in the sky. Their timekeeping must be adjusted relativistically according to
their position and velocity. An atomic clock on the bottom of a skyscraper ticks
faster than a similar previously synchronized clock at the top. Gravity is
simply stronger closer to the Earth's center and with its stronger grip slows
down all physical processes, including the measurement of time. Time
travel in the relativist sense (time dilation) happens all the time. When you arrive
from an air travel, you will have aged less than if you had stayed at home, and
more so, the faster you have traveled. This has been verified with atomic
clocks. For the same
reason, two spaceships moving towards or away from one another at great speed
cannot establish a common time frame. Furthermore, Relativity does not forbid
travel into the future, but it would be at a rate of acceleration so vast that
it is unlikely that it could ever be practicable on a human scale.
All
is not lost, however, for two persons in separate locations who wish to agree on
a common Now. If they are a short light travel distance apart their common
Nows are local, though they will always represent an approximation.
Another
mystery about the early universe is why there was not just one force. Many
physicists think there was only one to begin with and that it split up in the
first moments of Big Bang into the ones governing the universe today. There have
been several attempts to construct a Complete Unified Theory (CUT) which would
describe everything in the universe by incorporating the General Theory of
Relativity and the theory of Quantum Mechanics into one: a Quantum Theory of
Gravity, but it has proved extremely difficult to conciliate the General Theory,
which describes gravity and the cosmos on a large scale, with Quantum Mechanics,
which deals with phenomena on atomic and sub-atomic scales.
Yet
another difficulty has been that when reaching the interface between the laws
governing the General Theory of Relativity and Quantum Mechanics, according to
the General Theory, the 4th dimension, Time, will not allow itself to be
transformed into the quantum world where time has a much more ambiguous status.
At these ultra-small scales time becomes blurred or smeared out, and going
further back, before Planck’s Time (approximately 10-43
seconds after the Big
Bang), particles of matter move closer and closer together until the universe
becomes so dense that the known laws of physics are no longer able to explain
how time, space and matter emerged. “Finally”, everything merges into a
single infinitesimal point, the singularity. As it has zero extension,
talking of time totally loses its meaning. In agreement with the General Theory
of Relativity there was a first moment of time. As Stephen Hawking puts
it, Space-time was finite but without bounds: it had no beginning.
The Quantum Theory had a slower but earlier start. In 1900, the German physicist Max Planck postulated that energy could only be transmitted in discrete units, which he called quanta.
Lord Rutherford’s model of the atom, developed a few
years later, is arguably the last theory where matter maintained its character
of old-fashioned matter, with atoms consisting of a sun-like nucleus, surrounded
by swarms of planet-like electrons.
The
model that came after this, published in 1913 by the Danish physicist Niels
Bohr, who was one of Lord Rutherford’s students and later his collaborator,
showed worrying signs of matter beginning to lose its innocence. Bohr’s model
posited that the hydrogen atom consisted of a nucleus with only one proton and
with one electron in orbit round the it. The electron can only move in distinct,
discrete orbits at distances from the nucleus determined by quantum laws, but it
can jump from one orbit to another without passing the intermediate space!
Things
got curiouser and curiouser. In 1925, the French physicist Louis-Victor de
Broglie declared that ‘the electron is both particle and wave’, and in an
attempt to solve certain problems concerning Bohr’s model of the atom, the
Austrian physicist Erwin Schrödinger in 1926 developed his wave equations,
which described the wave behaviour of Bohr’s hydrogen atom, while at the same
time removing it further from any possibility of visualization. Schrödinger was
a prodigious scientist. He single-handedly reshaped current thinking in
cosmology, wave mechanics, statistical mechanics, unified field theories,
theoretical chemistry and molecular biology.
In
1927, the German physicist Werner Heisenberg formulated the Uncertainty
Principle which states the impossibility of simultaneously measuring
the position of a particle without disturbing its velocity and vice versa.
Knowledge about position and velocity are said to be complementary, that
is, they cannot be precise at one and the same time. This is due to the
measurement having an effect on the object observed: either the velocity or the
position will be altered, i.e. the observer will always influence the object
under observation. The Uncertainty Principle has had a profound influence on the
way physicists and philosophers think. It did away with absolute certainty in
nature and it has invalidated the law of causality in microcosmos.
Bohr then summarized the theoretical results of quantum mechanics in his
famous ‘Principle of Complementarity’ under which one must choose in advance
whether an experiment aims at describing an atomic scale phenomenon as a wave or
a particle as they exclude one another in the same experiment. But at the same
time the experimental results from both reference frames complement one another
so that only their collective description gives a true picture of the
phenomenon.
In Bohr's interpretation, the trinity of the experimental set-up, the
subjects of the experiment (electrons, photons), and the observer, constituted
an inseparable entity. Before being observed, an object only "exists"
as a probability, the experimental set-up defining in advance whether
observation will give rise to particle or wave. The observer
"actualizes" the phenomenon by observing it, but at the same time
alters it.
Among many others, this duality inspired Werner Heisenberg to point out
the resemblance of complementarity to the Cartesian dualism between matter and
spirit, and the Austrian Wolfgang Pauli, another physicist, to urge for an
understanding in our daily lives of body and soul as two complementary aspects
of the same reality.
Non-locality is a genuine, scientifically proven occurrence, one of
the most singular in all quantum mechanics. An example of this phenomenon is an
experiment in which a pair of electrons is emitted from an atom in opposite
directions. At that instant they only exist as probability waves: only when one
of them (A) is observed does it collapse and becomes a particle, but at the same
instant the other one, (B), collapses as well, however far it was from (A). But
this is not the whole story: (A) becomes materialized with certain properties,
including a specific orientation (a), while (B) materializes instantaneously
with complementary polarization (b). In principle (A) and (B) could be light
years apart, despite which (B) will immediately know it must have complementary
polarization. The principle is so well established that it has even been used in
the exchange of unbreakable code messages, and research is currently being made
into its further use in IT.
One
consequence of Bohr's interpretation of this phenomenon is that an electron in
an experiment acts as if it had instant information: knowledge not only of its
immediate surroundings but of what is going on throughout the entire
experimental set-up. It was one of the factors that led to the famous dispute
between Bohr and Einstein. The latter could not accept this "ghost action
at a distance". In the years between 1927 and 1935 the two met several
times and corresponded briskly in what was later to be labeled ‘The
Bohr-Einstein Debate’, arguably one of the greatest disputes in the history of
science. Einstein posited an objective reality behind the quantum phenomena, a
kind of Kantian ‘Das Ding an sich’. His outlook on physical reality was that
all objects have definite, observer-independent properties at all times, that
all events obey strictly deterministic laws and have local causes.
Bohr’s
outlook was slightly different, hence their yearlong discussions. Bohr was
pragmatic, his thesis being that the quantum theory precludes a classical
space-time description of the behaviour of microphysical objects. In the
Copenhagen interpretation, unmeasured microphysical objects have no definite
values. It is the measurements that ‘create’ the values of the observables.
According to Bohr it is not meaningful to talk of the existence of an object
before it is measured. The measurement reveals the properties of the object. At
the same time it changes the object and in such a way that that there is no
method by which the state of the object before the measurement can be calculated
with exactness, and no way to tell where the object would have been, had it not
been measured.
This incertitude was of little importance to Bohr. He regarded the
description of an experiment as one aspect of reality which could be
supplemented with others, thus giving an increasingly adequate understanding of
the world. He thought that the probing stone of a theory was its usefulness in
making sense of, and putting order in, our sensory experiences.
Opposition from traditional physicists was sometimes bitter. However,
quantum physics was so well established that only few physicists disagreed with
its results. It was this interpretation and its ontological
implications that gave rise to discussion. It was clearly a dispute about usage
of the language and analysis of concepts: What does one understand by "an
objective observer"? What is "reality"? What can one associate
with the word "infinite"? Does a probability wave exist before it is
observed? What do we understand by "simultaneity'? Is the laboratory part
of the experimental set-up? If so, what about the institute housing the
laboratory? What about the Earth? The Universe?
Does our physical view of the world depend on our culture? Would
"intelligent" beings on another planet devise physical theories
resembling ours or would they attach importance to quite different values,
perhaps ignoring mathematics altogether? Or is maths a universal phenomenon -
perhaps the only language we have in common with other
"civilisations"?
Some scientists agreed with Niels Bohr that we must augment our everyday
language to accommodate acquired knowledge. Others, including Soviet Russian
research workers and politicians (Lenin had a few harsh words to say
along the way), rejected it on the grounds that it was contrary to dialectical
materialism. Yet others pointed out the impossibility of visualizing the new
physics and being able to put it into words- for the only certain way of
describing the new reality they referred to the systematics of quantum
mechanics.
The most radical interpretation was that of John Wheeler who, among
others, held that only a conscious observer of the wave function of
quantum mechanics could bring about collapse and thereby make it exist:
"The Universe only exists because we observe it". This is the same as
saying that if a tree blows down on an desert island, is it non-existent until
it is acknowledged by a conscious person? Which raises the questions, Can an
animal which sees the tree blow down collapse its wave function? Where is the
borderline in the animal world? Are the numbers of conscious observers or the
size of the objects significant? What happens to an object which is not observed
for a long period of time?
Together with the mathematician Richard Feynman, Wheeler later elaborated
the theory of "absorption", according to which an electron that
wriggles and jiggles emits a "delayed" wave into the future (the
normal process) at the same time as sending an "advanced" wave back
into the past. When a wave meets another electron it makes it jiggle, whereupon
it, too, transmits waves forward into the future and back into the past, and so
on and so on until the entire Universe is jiggling. Most of these waves
neutralize one another, but a few persist and undulate back to the original
electron. All the processes occur simultaneously.
John Cramer further developed the Wheeler-Feynman theory, which strictly
speaking was a classical one, into a purely mechanical theory, which later
inspired the development of the String theory.
Other critics of the Copenhagen interpretation tried to relate the
concepts of quantum mechanics back to classical physics, among them David Bohm.
He holds that elementary particles and waves exist objectively, whether they are
being observed or not. But this assertion led to contradictions which could only
be solved by introducing postulates which have not yet been scientifically
proven. For instance, he introduced a field which was undetectable and took on
indefinite values at certain points. Hence, it has been dubbed a ‘ghost
field’.
In
a series of lectures, Sir James Jeans had ventured the famous remarks about our
knowledge tending towards a non-mechanical reality and the universe more and
more resembling a great thought rather than a big machine, and Sir Arthur
Eddington had written his well-known parable about the two desks in his study:
the one being a solid, antique desk, the one next to it the desk as the
physicists perceive it, a shadow desk with shadow ink and shadow writing paper.
In the 1940s, the theory of virtual particles was launched.They are pairs of particles and antiparticles which spontaneously emerge out of nowhere, then annihilate one another and vanish. This happens so quickly that they cease to exist before they can be detected, so it is disputable whether they can be said to exist at all. At any rate, they served to explain otherwise obstinate problems but at the same time they seemed to violate basic physical laws.
The Standard
Model of particle physics is, arguably, the most successful theory to date
in the history of science. It was developed in the 1970s and 1980s as an
extension of the Quantum Electrodynamic, or QED, theory which was
worked out in the first half of the 19th century. The model introduced two
groups of subatomic particles, the fermions and the bosons,
and it claims that these together encompass all known matter and all known
nongravitational forces in the universe. The fermions are matter particles
and include quarks and leptons. Triplets of quarks form
protons and neutrons which together constitute the atomic nuclei. Leptons are
involved in the construction of electrons and the weightless neutrinos.
Furthermore, the model describes all known nongravitational forces, namely
the electromagnetic, strong and weak forces. They are produced and carried by
force particles, collectively called bosons. The first is the photon
which holds the electron in its orbit. The second is the gluon which
holds protons, neutrons and nuclei together. The W and Z bosons
are involved in the formation of chemical elements. Finally, the model
postulates the Higgs boson. It has never been detected, but its field is
being felt everywhere, and its mechanism is responsible for all the
masses of the elementary particles, according to the Standard Model. Neither has
the graviton been detected. It is believed to transmit the gravitational
force. But assuming that they exist, these two together with the already
mentioned fundamental particles can in principle explain all physical
phenomena, atomic nuclei, atoms, molecules, chemical substances, plants,
animals, stars, solar systems, galaxies and perhaps even the universe. This is
the strongest circumstantial evidence in favour of the Standard Model.
The predictions of the model have been confirmed
by countless experiments. It has given us a more profound insight into the
workings of the everyday world, underlying, as it does, our understanding of
chemistry, atomic and subatomic physics, electronics and even biology. In
addition it has highlighted some of the deepest problems in cosmology, so that
today it is justified to talk of “particle cosmology”.
In spite of its success the standard model has some irreparable flaws, the
most important being that it has nothing to say about gravity. Most
theoretical physicists believe that in the first moments after Big Bang there
reigned only one force which soon parted into the four known: gravity,
electromagnetism and the weak and strong forces. Currently, physicists are attempting
to create grand unification theories, or GUTs, which combine three of the
four forces, leaving gravity out. None of the GUTs have been confirmed
experimentally. Another flaw is that the model considers electrons and quarks as
being pointlike - without extent and structure.
But new, more comprehensive theories have been put
forward, as for instance the superstring theories, developed by Michael
Green and John Schwarz in 1981. Originally they described the forces
between the sub-atomic particles as vibrating strings, but it was later
discovered that a variant could describe the gravitational force. This led to
the development of other string versions which seemingly explained yet other
phenomena. At one time there were about twenty string theories in circulation
but eventually they got pruned down to five. Subsequently the theoretical
physicist Edward Witten showed that they were, essentially, interpretations of
the same underlying principles. They all work with a number of additional
dimensions in excess of our four classic space-time ones. Some theories dealt
with 16 extra dimensions, but at the present it seems that the wheel has stopped
at six. Being curled up tightly, they are so diminutive that they are beyond
physical detection.
The
loop quantum gravity theory purports to give an answer to the
incompatibility between Quantum Mechanics and the General Theory of Relativity
by enlarging the General Theory to include a “quantum description” of
matter, time and space at very small scales. Not only does it extend time back
to the singularity, it proposes that time continued before Big Bang, but in a
reverse mode and with matter and space contracting rapidly towards the
singularity, though from its other side. Not only does it introduce infinity, it
also predicts that space and time consist of discrete, though infinitesimally
small lumps, just as matter has been known to do for a long time. In the case of time, one lump would be about the same
as Planck Time, 10-43 second. In the quantum network, areas and volumes are finite and
indivisible. There can be no singularity, because space just cannot get that
small. Since the theory no longer breaks down, time can be followed back beyond
what had previously been viewed as the beginning, the singularity. It should be
added that the theory is highly speculative.
To
overcome the disagreements inherent in quantum theory some have even attempted
to construct a completely new logic, a ‘quantum logic’ as opposed to (or as
a supplement to) our classical logic, to explain the odd behaviour of
microparticles in quantum experiments. The problem with this is that to explain
quantum logic one is forced to use common-language logic, engendered by our
mind, thereby so to speak using the enemy’s tools or the opponent’s
arguments against oneself.
Then there are the plasma state theory and the good old steady
state theory, the latter having been rejected and re-proposed several times
over the years. It claims that the universe has
always been there and that matter disappears at the same rate as it is
re-created. Other late-comers are t'Hooft and Susskind's extension
of the string theory into a holographic worldview and Witten and Townsend's
quantized membrane theory ('branes' for short). But the ultimate aim
of all these theories is to establish a Theory of Everything, or TOE,
which would include gravity and unify all particles and forces in one single
theory. This would unite the physics of the infinitesimal with that of
macrocosm.
What
remains on our mental retina is a picture of a flimsy, nearly void universe with
ambiguous or even mysterious qualities: forces that act instantaneously at a
distance (gravity); 'ghost-fields', particles that move faster than the speed of
light; mass-less, charge-less neutrinos that do not interact with matter;
virtual particles, electrons with negative mass and energy; ultra-short quantum
processes going backwards in time, the production in the laboratories of
anti-particles; theories of parallel universes, of additional dimensions of space and
time, of the law of causation breaking down, etc. All these theories have
contributed to our present difficulty in visualizing the physicists’ universe
and have forced us to renounce from any useful description other than what the
priviledged quantum and relativity mathematicians afford us: All
these theories and others are in essence mathematical; they succeed in solving most
of the essential problems in conciliating the laws of the very small and the
very large, but none of them solve them all.
Whatever interpretation of the quantum theory one prefers, there is one
thing one must take into account: the role of the observer. Is one's state of
mind in some way an essential component in the collapse of a wave function? The
mind is normally sited in the brain, and its electrochemistry involves quantum
processes. Obviously, there must be an interface between them and our thought
processes, our language, our consciousness and intelligence. More on this anon.
Let us take a closer look at the perhaps most mysterious of the Time,
Space and Matter trinity: Time.
Since
antiquity, “the present” has been depicted as a mathematical point seen
moving along a time line. This naïve but useful representation results in
the contradiction that the past no longer exists, the future does not yet do so,
and the present is a mathematical point without extent, i.e. it does not exist
either. Before Einstein, this contradiction was mostly ignored, also by
physicists who implicitly held that time was simply there, detached from
space and matter. One famous example is
Isaac Newton who thought of time as an entity, separate from and independent of
space.
Physicists place time in a
timescape analogous to a landscape, containing past as well as future events
(they do not mention the Now!). The problem with this model is that it does not
explain the progression of the Now, and it has a distinct flavour of determinism
which is incompatible with either quantum mechanics or the chaos theories. It
opens the door to futile speculations about virtual or real time travel,
entailing logical and epistemological contradictions, as when Alice travels back
in time and kills her grandmother in the cradle, thereby preventing her own
birth, and so on.
Using
Ockham’s Razor (“if there are several options, choose the simplest”) I
consider the following to be a sensible guess at an overall worldview:
The
past does not exist.
The statement seems trivial. But it nevertheless
merits some consideration:
to physicists, as we saw, it is part of a timescape. To some philosophers it is
what is “left behind” when the Now moves forward as a cross section of the
Whole. Some psychics claim to be able to drag material objects out of the past,
the so-called Apport Phenomena. One famous example was Uri Geller. Were
apport phenomena a reality it would imply that the past indeed exists
“somewhere”, for instance in the physicists’ timescape. To us ordinary
people it is a more fleeting entity. Recent events, which for psychological or
physical reasons leave a strong impression upon us, “stay with us”: they are
still here! Events of lesser impact evaporate more quickly into the past. In
short, our concept of “the past”, like that of “time”, is determined
psychologically. What is written below about the existence of time applies
equally well here. But in the physical Universe ‘past’ is simply what was
Now but a fraction of a second ago.
There
is no eternal Now.
There is a succession of presents, of Nows. Each one is the real world, whether
we are there to observe it or not. There
are as many Nows as there are events in the Universe. It is the events contained
in each Now that trigger the events in the next and determine their state. Thus,
each Now must “know” all the laws of nature in order to cause the changes
the next Now will contain.
Would
time exist in this universe? No, “Time”
as such does not exist except in the
heads of humans, and mental time, as we have seen, is an extremely complex
thing. What makes the perception of time as a reality so convincing is our
highly developed brains and especially our memory; we will swear that the house
we saw there, or rather remember we saw, a minute ago or yesterday or 10 years
ago, is the same house we have in front of us now. But it is not. It is a
similar house; even the jump of an electron from one shell to another in the
house is enough to in principle make it into another, a new house (the
electron receives or emits an electromagnetic pulse). But for our convenience,
evolution has chosen to give us the tools to perceive a progression of, for
instance, near-identical houses as being represented in the brain as one and the
same house. The same tools are at work on everything we perceive in the course
of the evolving of our present, including ourselves! Remember as well that also we
change with the change from one moment to the next, though usually only
imperceptibly.
Do I share the Now with my neighbor? Does it encompass our immediate surroundings? Yes, but the more distant events we wish to include in our present, the more obsolete they become. Remember that light from the Sun reaches us with an 8 minutes delay and from the Andromeda galaxy after 2.4 billion years. Astronomers and cosmologist talk of the Sun and of Andromeda as if they are here now, and for practical purposes we tacitly adopt this usage. I have dealt with this convention at greater length in the latter paragraphs of Part I, but I would like to reiterate that truly simultaneous events are those that occur at the same place.
Does
the present have extension in time? Logically speaking, No! Any moment in
time, however short, would be divisible into at least two parts. Of these, one
would have to be the present and, of course, the other the past. The past and
the present cannot exist simultaneously, so we must conclude that the present
has no duration!
Does
the future exist, when future events have not yet materialized. To
physicists they belong to the timescape. To certain philosophers they are a
reality, awaiting the cross section of the Whole, the Now, to materialize them.
To Extra Sensory Perception (ESP) researchers it is all about precognition, the
faculty to acquire information about future events without use of the senses.
Assuming precognition is a reality, it cries out for an epistemological
explanation.
In
his paper ‘The Physics of Now’, The
cosmologist J. B. Hartle
says, “The present extends over a finite interval …” and he quotes the
19th century American psychologist William James for saying in his Principles
of Psychology: “…the practically cognised present is no knife-edge, but
a saddleback, with a certain breadth of its own, on which we sit perched, and
from which we look in two directions in time.” Of course, this metaphor should
not be taken seriously in a scientific context, but if indeed the present has an
extension, and if we maintain our assertion that the past does not exist, we are
left with the possibility that our present incorporates a mystical factor which
may trigger future events with a high propensity for happening. I will return to
this intriguing prospect in Part III, “Is There More To Us Than That?”
We
could fill book upon book and megabyte upon megabyte with physicists’,
neurophysiologists’, neuropsychologists’, theologians’ and philosophers’
often very imaginative or contradictory statements and theories about Time, so
for the time being (!) let’s leave it at that.
In my simple model of the physical cosmos, our present, Now”1”, is followed by Now”2”, whereafter Now”1” no longer exists except in the memory of humans and some animals where it is placed as “the past”, and only a fractional part of it at that. Subsequently comes a new, almost identical Now”3” and so on ad infinitum. Obviously, the Now must shift in bits, in infinitesimally short pulses. Recent theories in quantum physics have speculated that something similar happens in the quantum world; that time comes in ultra-short pulses, each being of the shortest possible time interval of 10-43 seconds - the Planck Time. This, then, would be the duration of each Now. Each universal Now carries inherent all the natural laws that create or cause the following Now which then ‘inherits’ these laws to initiate the next group of events, thus canceling the previous Now etc. ad infinitum or rather, up to where we are Now.
If
what I have conjectured above about the past, present and future is correct,
then the only reality is the present, the ever-changing Now, and the sensation
that it extends into the past is an illusion, produced by the fact that we
experience each moment of the present, each Now, as different from earlier
moments which we still remember. We all feel we are participating in a
common present, but in a relativistic sense it is meaningless to talk of a common
Now, a sort of collective Now, valid for entire Mankind, let alone the Earth
or the universe.
On
a terrestrial scale, we each have our Now, and that Now may be equated with our self.
It is something wholly personal, something subjective. The self is each being's
consciousness about itself and the surrounding world, but it is an ever-changing
entity shaped by sensory impressions, interacting with the physical, human and
cultural environment, influenced by it and influencing it, dispatching
memorybits from each moment into the memory bank, all being supported by a
common history. It is this totality which, underpinned by one’s genetic
makeup, produces the sensation of self, of identity.
We must return to the natural constants.
The values themselves are well understood, so well in fact that physicists are
able to calculate that had the value of one or another of them been just
a fraction different (in one case we are talking of a difference of less than a
billionth), we would not be here. And the universe would probably not be here
either.
This
has led to speculation that the universe has been custom-made from the start
(or, indeed from before the start) to eventually reach the provisional end
result, Man, and that this infers an original master-plan, which again suggests
a Creator. This is the teleological argument, and I would like to stress
that it is based entirely on faith. No scientific fact supports it. I will
return to this later.
More
epistemological is the anthropoid argument: “that we are here because
we are here”, which can be re-phrased as: We all seem to be living in and
observing the same universe. This should not surprise us; we are simply the
lucky draw in the cosmic lottery of possible universes. Had our universe been
different, we would not be here to watch it. But the fact that we are
here at least tells the physicists one obvious but nevertheless important fact:
that, given the physical constants as they are, life has emerged, so it
is up to them to pursue the disclosure of a subset of laws that has taken our
planet through all its stages to conclude in the emergence of rational beings.
Custom-made
or not, the interaction of the constants have produced this immensely complex,
13.7 billion years old universe, so let us try to flesh out in a little more
detail the prerequisites for the emergence of habitable planets and therefore life.
The
astrophysicists talk of a star’s ecosphere to denominate the ring-shaped zone
around it where the surface temperature of its posited planets is such that
liquid water can exist for a few billion years for life to have any chance to
emerge and proliferate. This zone is also called CHZ (The Circumstellar
Habitable Zone) and applies not only to individual suns but to the entire Milky
Way where the inner and outer regions are uninhabitable, leaving only the middle
band for possible habitation. Had our Sun not been found in the habitable zone
of the Milky Way (its CHZ) and had our planet not emerged in the corresponding
CHZ round the Sun, it would never have been able to support life as we know it.
However,
its position in the habitable zone was no guarantee for life to develop. During
its formation and after it had settled as a planet circling the Sun, it still
faced about 4.5 billion years of myriads of turbulent events related to the
size, age and composition of the Sun and the interstellar dust whirling round
it, events that interacted with the almost simultaneous formation of the
planet’s own size, chemical composition, temperature and speed round the Sun.
Had any of these properties been slightly different, Earth would have been
lifeless today.
Moreover,
it is likely that genuine random events have played an important role in the
evolution of the Earth, especially as a consequence of the nuclear processes in
the core of the Sun. Whenever randomness takes the stage, even a super computer
fed with all pertinent data about our galaxy, and especially the region where
the Sun was beginning to form 4.7 billion years ago, and provided with all the
necessary equations, would not have been able to predict the emergence of the
first single-cell micro-organisms.
The
question as to whether there is life or even other civilizations “out there”
has fascinated mankind for ages, and ever since our technology has permitted it
the search has been going on, ever more systematized and intensified, both
through direct efforts and as a by-product of space exploration. In 1975, the
astronomers Frank Drake and Carl Sagan began sweeping the skies with the 305
meters radio telescope at the Arecibo Observatory in Puerto Rico for intelligent
signals from the universe. The search was soon dubbed SETI (the Search for
Extraterrestrial Intelligence), and it has been undertaken in various places,
some of them via radio astronomy (searching through the radio window) and others
using optical telescopes (searching through the optical window). The radio
search out to distances of 40,000 light-years has been especially intense and
has thus covered a considerable portion of our galaxy and the space surrounding
it.
Another
approach has been probability calculus which astronomers and astrobiologists
have applied to pin down the extent of the window of communication available to
us, but as in all speculative science there is vast disagreement as to which
figures to apply. Many astronomers believe that our galaxy must have been
inhabited by several billion technological civilizations during its history. The
fact that we have not been able to detect a single significant signal from any
of this vast amount is really telling.
This
could have several causes: earth-bound ones such as lack of funding and
technological limitations, for instance. Another could be that other
civilizations have chosen or been forced to seek other means of communication,
for instance with gravitons (if they exist). Some have even suggested that they
use telepathy. Yet another possibility could be that technological civilizations
have a built-in mechanism which, after a certain time, brings about their
self-destruction too fast for us to be able to notice them. Or we do not spot
them because they have not yet advanced to an identifiable stage. Or our
definitions of life do not cover their life forms. The most gloomy but perhaps
also the least probable reason would be that life has simply not manifested
itself anywhere else.
Should
we, however, encounter life forms not based on DNA, this together with the
ubiquity of interstellar organic molecules would suggest to some scientists that
life evolves wherever and whenever it can. The catch is of course that the
argument presupposes knowledge of laws governing a nature with which we will
have had no previous encounter and which is therefore at best speculative.
But
it could be argued that as we consider the universe to be homogeneous and
isotropic, life on another planet – however remote – could have evolved
using building blocks similar to the ones which have produced the foundations
for our life forms and that it would therefore have recognisable traits.
These would probably have to be a kind of DNA molecules. What are the prospects
that these immensely large molecules with their mechanisms for producing
chemicals that in turn transmit information for the synthesis of thousands of
proteins which again control the formation of cells, tissues and organisms like
ourselves, could have formed by sheer accident somewhere else in the universe?
Life
on our planet originated in organic but lifeless, self-replicating molecules.
One such is the DNA molecule, but it is believed that this was too sophisticated
and highly developed and therefore dependent on a similarly sophisticated
environment to have itself been part of the first living organisms. It is more
likely that relatively simple prokaryotes whose DNA floats around inside
the cell and which include bacteria and blue-green algae, joined up to form the
first eukaryotes (cells with an internal nucleus), which divided into
protista (unicellular organisms) fungi, plants and animals such as insects,
fishes, reptiles, birds and mammals like ourselves.
Although
DNA today is different in different life forms, the basic mechanism by which any
form of life, whether in bacteria, plants, insects, fishes or mammals, copies
itself or merges with DNA from other cells, is in principle identical. (I
exclude virus as it can hardly in itself be considered a living organism). But
apart from identical twins, not two living beings have identical DNA.
In
the course of life’s some 4 billion years on Earth, gradual changes in the
environment as well as random accidents have produced mutations in the genes,
carried by the DNA molecules, resulting in the emergence of new species and the
destruction of others. The environment itself is an ever-changing entity,
interacting with the populations and being influenced by interstellar,
extraterrestrial and terrestrial accidents. The close passage of a star could
have augmented the radiation and thereby the number of mutations in the genes.
In the course of its history, immense numbers of asteroids and comets of varying
sizes and angles of impact have hit the Earth. Some of those have nearly
destroyed all life, and the interaction of what was left of life forms was
obviously vital to the development of hominines (proto-humans) and humans.
Severe
climatic changes such as volcanic eruptions, changes in the composition of the
atmosphere, etc. have affected biological productivity; global glaciation, which
took place about 2.3 billion years and again about 600 million years ago and
lasted several million years, delayed the emergence of multicellular organisms,
and consequently animal life. The
length of time single-cell life was alone on Earth – estimated at almost 3
billion years – was of great importance to the occurrence of
multicellular life. But we know fossils aged almost 600 million years, and they
prove that animal life was abundant then.
The
lack of any one of these billions of incidents or a reversal in their order of
occurrence or a different combination would have been sufficient to ensure that
the proud end-result - Man - never materialized. This is not an entirely
improbable assumption, as we have already seen. Then life could for that matter
continue as it looked before the appearance of Man, which would in many ways be
more beneficent to the species. There would be no wars or conflicts, no
overpopulation, no science and technology, no religion or philosophy, and no
Homo sapiens to invent the concept of polytheism or monotheism, whether
Proto-Christian, Semitic, Islamic, Christian or Buddhist. Would God then exist?
I think not.
To
me it is inconceivable that all these billions of essentially random happenings
with the trillions and trillions of environmental events they have in turn
generated to finally produce the DNA molecule that made, Man should have been
duplicated in exactly the same sequence anywhere and at any time in the
universe, let alone within an accessible distance in space and time from us. The
most accessible distance in space and time would be precisely where we are, on
Earth.
The
astronomer Ian Crawford argues convincingly that as life in the galaxy has had a
theoretical head start on us of a few billion years, and as we must suppose that
colonization spreads exponentially through the galaxy, alien civilizations could
easily have visited Earth when it was still populated by single-cell organisms
that could hardly put up any resistance. But nothing indicates that Earth has
ever been invaded by foreign life or, more importantly, been colonized by
technological civilizations. And this in spite of our planet actually finding
itself in clover as planets go – as astrophysicists and astrobiologists
consider it. A prudent colonizing civilization would put it very high on its
“shopping list”, and it looks increasingly unlikely that we will find other
planets with a complete set of properties nearly identical to those of Earth in
the demanding and hostile surroundings out there.
The
conclusions as to the chances of encountering ET civilizations, let alone life,
span from that of the biochemist Christian de Duve, who says that “Life is
almost bound to arise…” to the opposite as expressed in 1983 by the
physicist Brandon Carter who said that “civilizations comparable with our own
are likely to be exceedingly rare, even if locations as favourable as our own
are of common occurrence in the galaxy”. The total lack of success seems to
support the latter statement. On a similar note, the nuclear physicist Enrico
Fermi in 1950 asked the now famous question, called the Fermi Paradox,
‘If ET civilizations are commonplace, where are they? Should their presence
not be obvious?’.
I
see the urge to look for other civilisations or other life forms in the universe
as sparked by sheer human or scientific curiosity. Perhaps I should add greed;
imagine what we might learn (read ‘steal’) from other, more advanced
technological civilizations. Considering the previous track record of humanity,
I find the thought that we might some day encounter a human-like civilisation
similar to or worse - identical with ours, scary. Let us consider the
possibilities for a moment.
Imagine
that the alien civilization proved to be technologically and intellectually
inferior to ours. In no time, cosmologically speaking, we would subjugate or
even destroy it. Imagine, conversely, that it has a technological and
intellectual edge on us. Would it not be reasonable to assume that it would do
away with us in the quickest possible way? It would be naïve to think that they
received us waving Union Jacks, Stars and Stripes, Tricolours or any other
national standard and that they would address us in English, Danish or any other
intelligible language. Or to assume that they possess speech organs similar to
ours.
Even
more scary: we might encounter a phenomenon that we would not recognize as “a
life form”, yet it may display unknown and unimaginable means of proliferation
and internal communication, means which, precisely because of our previous lack
of experience with the phenomenon, might prove fatal to humanity in several
ways.
Why
is the thought of colonizing other planets so attractive to so many people? I
think it is perhaps linked to fears of overpopulation of the Earth and the
ensuing scarcity of water, food, raw materials etc. Although these are well-founded fears, let us consider the implications from a more remote and
objective angle; we are all given a limited span of time here. When our time is
up we are gone and do not have to worry about the future of mankind. And
worrying in an abstract way on behalf of unborn generations that might even be
better off having never been born seems to me futile and raises the question:
What is so splendid and glorious about humanity? I am not talking about the
lives of individuals and their loved ones, their joys, sorrows and sufferings. I
am talking of the totality of humanity in space and time, this infinitesimally
small clot of live, self-reproducing tissue on an inconspicuous planet in a
corner of the universe and with a history so short as to look more like an
accident.
I
mentioned the anthropic principle above (We are here because we are
here). Apart from philosophical deliberations on this brain-wrecking concept,
Western theologians in particular have used it to support their claim that it
proves the universe to be the work a Creator. What puzzles me is that God did
not enter the picture before life had existed on Earth for about 4 billion
years, and He (By the way, why is He male, at least in the Western world?) did
not come at once. He waited quietly while hominids developed through numerous
stages, from Homo habilis, over Homo erectus and Homo sapiens to the provisional
end product, Homo sapiens sapiens.(I am using the Christian, monotheistic God.
Creator and Ruler of the Universe, to epitomize all earlier and later similar
Gods.)
Perhaps
He was not ready to take the stage. He waited about 100,000 years longer until
Homo sapiens had developed the ability to fantasize explanations of natural
phenomena, traumatic events, the causes for fear, anxiety and joy, and to
invent, not one but a huge number of “gods” whose devotees have ever since
fought for the right and power to make precisely their god global –
with all the tragic consequences so dismally demonstrated every day. But God
finally revealed Himself to a small Semitic tribe of nomads in the Near East. So
His presence has been as short as about a millionth of the full span of life on
Earth. Why did He wait so long?
The
usual answer from the theologians is that God is omnipotent, He could wait as
long as He pleased, and hereafter He would lead the evolution along ways that
are hidden to us uninitiated, so that the end product nevertheless became this
sublime product, Homo sapiens sapiens. Or perhaps He felt too great a deference
for the natural constants, realizing that He would have difficulty manipulating
them in such a delicate way that their combination did not fall down on one side
or the other of the knife edge where they had to balance in order to make
possible the evolution of the universe from BB through the multiple quantum
physical as well as astrophysical stages to a point in time 13,7 billion years
later where we were able to comment upon Him.
I
would like to mention a scenario that may solve the riddle of the anthropic
principle and perhaps even make it superfluous. Imagine that there has been an
infinite number of abortive Big Bangs, all of them emerging from singularities
(infinitesimal points in space-time where matter is infinitely dense), each with
its specific combination of natural constants that in turn gave birth to
laws of nature. The majority of these BBs displayed a deficient combination of
values of their constants and never formed elementary particles, so they petered
out after a period of time which perhaps only lasted some millionths of a
second. They disappeared without leaving a mark. Because matter had not yet had
time to form, and as the concept of time presupposes cyclic events in matter,
time did not exist between the individual unsuccessful eruptions.
But
“some day” in this timeless shadowy void, a
BB happened which had the right combination of the values for its natural
constants, and “our” universe was born! Now we can discuss if the natural
laws in this baby-universe with physical necessity will lead to this the most
sublime, preliminary end product, Homo sapiens sapiens. Actually, that is
not necessary. We are here, either as a consequence of an infinite array
of random coincidences or of stringent natural laws. Either way, we ought to
feel awe that either of these two scenarios has led to the formation of beings
able to construct the enormously complex systems of thought that man uses to
explain his physical surroundings and the theologians to legitimise their
spiritual convictions.
I
do not see anything degrading in accepting the fact that we are the descendants
of an originally lifeless gas cloud around an equally lifeless, hot gas globe. I
even find it more exciting and awesome that it has led to beings with
feelings, strong or weak, positive or negative, primitive or complex, with
fantasies and with thoughts. Let’s accept that we are moved by what we call
altruistic acts, that we are angered by the opposite, and that we have created
morals and ethics, useful but provisional social end products in the fight for
survival in our highly differentiated, complex society.
I
think we have pretty much gleaned the development
of the universe from dead matter, through the emergence of life on our planet to
the end product, Man. If you wish to study the subject more in depth (although
not at university level) I can recommend George Ellis’ ‘The Universe Around
Us’ which may be found at http://www.mth.uct.ac.za/~ellis/cosa.html
. The subtitle is ‘An Integrative View of Science and Cosmology’.
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