matter> infinoverse p1
The next three pages tell the story of how the universe was created in a quantum blip out of pure nothingness - the inflationary event that became the Big Bang. And then of course we we consider the same causal tale from the organicist's point of view.
welcome to the infinoverse
In philosophy they call it a Hard Problem. The capitals warn
of a question for which there seems no logically coherent way to get
from a "here" to a "there". How could the world, our Reality, burst
into being out of nothingness?
Think about it. True nothingness is not merely a void - the absence of
things. If you pump all the air out of a glass jar, you still have
space and time remaining. The laws of the Universe still apply. So the
emptiest possible vacuum is still merely an absence of particular
things in a place that already has some general existence. True
nothingness must be beyond all notion of place or time or law. It must
be beyond physics or even logic.
If we are being intellectually strict, it can't be thought about in
terms of things that either exist or don't exist. Nothingness
would not
even have room for no-thing. There must be an absence of absence itself!
So this certainly seems to make for a Hard Problem, if not an
Impossible Problem. To explain how something happens, we need to start
with some kind of thing, even a very minimal kind of thing, that then
gets somehow changed into a something else. But nothingness gives us no
place to start a causal sequence of events. There is no here that can
later be transformed into a there. And hence no conceivable reply to
the question of "why the existence of existence?".
The accepted response for people who have reached this stage of
questioning is simply to exclaim that we just have to accept that
Reality is and move on. To quote Wittgenstein: "Whereof one cannot
speak, thereof one must be silent." This would certainly make for an
agreeably short tale. We could finish right now.
But instead let's turn the whole problem on its head by suggesting an
entirely different approach. Not a novel approach, just an often
overlooked alternative. Rather than imagining that Reality sprang into
existence out of a nothingness, let's suppose that it emerged as an act
of constraint on a state of infinite everythingness.
What on earth does that mean? Well now the creation tale might go like
this. In the beginning was everything. Everything that could exist did
exist, and all at once, making it a plenum rather than a void. Let's
give this state of infinite everythingness a name and call it the
Infinoverse. This is to distinguish it from our rather less replete
Universe. The Infinoverse would be a realm where all possible
alternatives filled the one great place at the same time.
The pleasing fact is that, when you think about it, such a state of
everythingness would be so jam-packed that it would look pretty much
like our concept of nothingness. A place crammed with every kind of
stuff, all possible events, must leave no room to move, no real
possibility for change. Everything that could be...well, it already
would be! A completely solid block of stuff would be just as inherently
featureless as the emptiest vacuum.
Yet there is a crucial difference. You can carve away at a solid block.
You could take a state of infinite everythingness and constrain its
tremendous variety so that it became an expression of something more
particular, more finite. Most creation tales try to imagine
Reality
popping into being out of nothingness. The Infinoverse comes from the
other direction. We begin with a state of total being-ness of some sort
and then restrict it in order to shape the set of essential building
block materials - the particles, the forces; even space and time -
which are apparently the foundations of our physical existence.
It sounds crazy. A realm of total everythingness that gives birth to a
somethingness! But surely this is no more loopy than the idea that a
nothing could produce a something? So at worst, it is only crazy in a
different way. And if the Infinoverse shares all the essential
properties of a state of nothingness, such as a general
featurelessness, yet is also pregnant with the possibility of becoming
bent into a particular something, then it seems an idea at least worth
considering.
The big prize would be if the Infinoverse could be shown to have some
kind of logical necessity to exist - if it could bootstrap itself into
being out of pure causal exigency. Obviously, a state of absolute
nothingness has the great virtue of not demanding any kind of causal
explanation for its existence, or rather its absolute non-existence.
What is not there simply fails to be and that's the end of it. But that
is also why nothingness so completely fails to provide any kind of
ground for the generation of things that do then actually exist.
The Infinoverse, on the other hand, offers a literally infinite ground
for the production of realities. There may be many other kinds of
worlds apart from our own. And if it can be shown that in some subtle
sense, all things that can exist, must exist, then the Infinoverse may
indeed explain its own existence as well. To complete the 180 degree
twist on the standard creation tale, we may even find that the one
thing that cannot be produced, which cannot actually exist, is an
absence of thingness. Nothingness would be the very thing that cannot
be.
Of course, philosophers and theologians have been down this particular
road many times. Plato had his principle of Plenitude - anything that
can exist, must exist if the World is to be considered a perfect place.
Others have felt that "everythingness" is really what we mean by God.
Our Reality is a cut-down version of His infinite potential.
Some quite complex arguments have been floated along these lines. For
example, the German philosopher, Hegel, reasoned that God - absolute
being - logically implies its opposite, absolute non-being. This in
turn necessitates the idea of becoming, the road to unchanging being.
So this is where humans come in. We are needed to make the journey to
heavenly perfection and complete the completeness of God - a God that
encompasses everything, including such diametric opposites as stasis
and change.
We will see that Hegel was definitely on to something with his
dialectical style of argument. And a wealth of similarly intriguing
arguments have been made by Leibniz, Bergson, Whitehead, Peirce and
other famous “organic” thinkers. Plenty have been
willing to turn the conventional question about the origin of all
things on its head.
But what would it be like to take the Infinoverse route today now that
so much more seems certain about the true nature of Reality and the
origins of the Universe? What kind of physics emerges once we adopt a
different idea about the causality of the material world; one in which
we start with everything and then seek ways in which this vast pool of
potential spontaneously slims down - self-organises - to produce crisp
states of somethingness?
creatio ex nihilo
An Infinoverse that gets whittled down into Universes. Is
there room in 21st century cosmology for such an agreeably outrageous
idea?
A slight difficulty is that science seems to be doing quite well in
managing the ultimate conjuring trick of getting a something out of a
nothing. As you will no doubt have heard, it is pretty much established
fact that the Universe erupted into being with a Big Bang.
First mooted in the 1970s, the story has become stunningly precise in
its detail. The Universe began 13.7 billion years ago when an almost
infinitely small, hot and dense point of mass and energy exploded - an
explosion which also created the space and time into which the
explosion happened.
We can be quite sure about the fact of a Big Bang because when we look
out at the stars, they are expanding evenly in all directions. So run
the history of this expanding Universe backwards and we can see the
exact moment where everything that now exists must once have been found
at a single point.
Observation of the skies with radio telescopes has also revealed that
the Universe is bathed in a weak background radiation, a cosmic
afterglow which can only be the remnant of a Big Bang explosion. These
two bits of proof alone are enough to believe in the theory. But the
third and clincher is that calculations show only the heat of a Big
Bang could have baked the precise mix of chemical elements we find
about us. The balance of different kinds of atoms is just too exact to
be a coincidence.
So the entirety of our observable Reality began as a massively dense
and combustible point. And not even all that long ago given the earth
is a good 4.5 billion years old, and life on earth about 3.8 billion
years old. Then comes modern cosmology’s most wonderful
conjuring trick.
Quantum theory, a physical model developed to describe Reality over
very tiny times and distances, says that such a super-dense point could
simply blink into existence. The weirdness of quantum logic would
permit the raging seed that ballooned into our Universe some 14 billion
years ago to have emerged itself as a random blip, a chance breaking of
the infinite symmetry of a state of pure nothingness.
Now if quantum theory says something is possible then there is good
reason to believe it. Quantum theory is famously the most precise body
of equations ever produced by science. Some of its key predictions have
been shown to be accurate to eleven decimal places. And only the
difficulty of doing experiments of greater precision prevents still
more decimal places being added to the tally.
Furthermore, despite quantum theory's reputation for being strange and
difficult, it is in fact employed routinely in modern life. The theory
underpins the design of just about every bit of rocket age technology
from computer chips to brain scanners.
Of course, quantum theory is also famously weird. The way it works
seems to contradict some of our most cherished notions about causality.
This led Einstein to despair of it, and others to say that if you think
you actually understand it, then you haven't been paying proper
attention.
One of the tenets of quantum theory is that Reality becomes radically
uncertain when it is observed on the micro-scale. From a distance, a
particle will look to have a particular mass, location and speed. But
get right up close to observe a particle's properties at a specific
place at a specific time and the measurements go haywire. The numbers
become suddenly infinite.
The particle can turn out to have just about any speed or mass, or
indeed show up just about anywhere in the Universe. So quantum theory
says you cannot pin Reality down to something that possesses certain
existence. On the very finest scale, there is a fundamental jitter, a
smudging of Reality.
This is what seems so contradictory. Quantum theory is precise to at
least eleven decimal places because you can calculate exactly how much
of this jitter or uncertainty you should find in any situation. The
behaviour of an individual particle is in principle unknowable. It
appears that it can do just about what the heck it likes. However take
enough such examples of such a particle, and eventually its actions
will average out to create a tight statistical profile.
Physicists call this the quantum wavefunction, a curve in which mostly
particles behave in an average way but which also extends out to
infinity, making it at least possible for the occasional wild extreme
defiance of the norm.
One of the important consequences of this quantum fuzziness is that a
vacuum – plain empty space – can never actually be
empty. The uncertainty principle says that if we were to observe a
small stretch of space over a short enough time-scale, then it would be
forbidden to know something so definite as that this scrap of the
universe contains an absolutely zero amount of mass and energy. It
could only be zero on average!
The bizzare result is that the vacuum must seethe with particles of
boundless energy. Indeed, the tighter we might try to draw the noose on
a supposedly empty spot in space, the more radically uncertain we must
become about what is actually contained at that point. Looking closer
increases the likelihood of encountering particles of massive size,
speed and energy.
Physicists make sense of this baffling outcome of quantum logic by
saying that the vacuum continuously generates pairs of
“virtual” particles at every point. The particles
are matter and anti-matter – exact mirror-image twins in all
their properties. If one has negative charge, the other is positive. If
one has left spin, the other spins right. So effectively each cancels
out the existence of the other.
And in fact this is what generally happens. The virtual particles pop
into being and then annihalate each other almost immediately. This
rapid quantum book-keeping successfully honours the uncertainty
principle while also keeping the vacuum generally empty as its supposed
to be.
Under the right experimental conditions, this underlying roil of the
vacuum – the “zero point” energy
– can actually be observed. If two metal plates are hung
almost touching in a vacuum jar then the narrow gap between them
physically restricts the wavelength of the virtual particles that can
make an appearance in the space. Larger frequency particles simply
can’t fit. This sets up a pressure difference in which the
greater activity possible around the two plates pushes them together -
a phenomenon known as the Casimir effect after the Dutch
physicist who
first suggested the experiment in 1948.
These virtual particles – particles out of thin air!
– explain all sorts of other phenomena from the impossibility
of eliminating noise in electronic circuits to the evaporation of black
holes. They even seem to explain why the three basic forces of nature,
electromagnetism, the weak and the strong force, have their different
strength and character. The ever-present fog of virtual particles that
pervades all empty space is thought to interact with passing charged
particles in slightly differing ways.
But what matters here, of course, is the fact that the seething of the
quantum vacuum must challenge our ordinary notions of nothingness. From
a distance, like the surface of the sea, empty space looks dead flat, a
place where nothing is happening. But zoom in close and we find an
increasingly wild pitch and toss of virtual events. There is no real
zero-ness - a proper sea level - to be found. The zero state that
represents the vacuum’s nothingness is just an imaginary line
drawn through the average of a lot of actual activity– all
the pluses and minuses of fleeting particle pairs.
At best we might say it is where Reality would come to rest if the
fabric of space and time could manage to do what is in fact quantumly
impossible, and that is to lie dead calm.
Whoops! Already, too soon in the story, we are glimpsing how
nothingness might be the limit – the unreachable
limit – of that which exists, rather than its
origin. Nothingness
lies at the end of our journey as a kind of ultimate goal rather than
being the place from which all things begin.
But anyway, it should be clear the quantum realm is a strange place
where standard notions about energy and particles, and even space and
time, start to break down. It is a region where - temporarily, at least
- we can extract a certain kind of something from a certain kind of
nothing. Let’s stick to the conventional terminology for the
moment.
the universe by the numbers
In the 1970s, cosmologists like Edward Tryon of Columbia
University
boldly took the idea of virtual particles and the restless vacuum to
see what they might say about the Universe at the pin-point moment of
the Big Bang, back when the entire Universe itself would have been
small enough to be ruled by quantum logic.
Now the quantum frothing of Reality only begins to kick in at the
Planck scale, which is almost unimaginably tiny in terms of space and
time. The Planck length is just 10-33 cm. To get
an idea of what this
means, let's start with much larger objects like atoms and peas.
An atom is about 10-13 cm across - a whole 20
orders of magnitude
bigger than the Planck scale. And a pea can fit a lot of atoms - about
1024. To represent all the atoms in a pea,
imagine making a metre-long
row of a thousand dots with a sharp pencil. One per millimetre. Fill
the sheet of paper with a thousand rows to form a neat square. Then
stack up a thousand sheets like this to make a cube of dots. With this
first stack - which will only have taken you five years to create - you
would have a billion dots.
Sadly you’re hardly off the start line. Now form a line of a
thousand paper stacks. Then a thousand of these rows to create a
square. Survey the knee-deep carpet of paper covering a whole sports
field – 1015 dots, or about the number
of cells in the human
body. Anyway, next stack up a thousand sports fields to make a sky-high
cube. Form a line of a thousand such cubes. A thousand of these to make
a square. Finally you have a mountain of paper about 100 stories high
and covering a small country. You also have enough dots to match the
number of atoms to be found in a pea.
Well, that is a 13 order of magnitude difference and it is another 20
to work your way down from atoms to the fuzzy Planck realm. If you
inflated an atom to the size of the known Universe, then a Planck-scale
object would be about the size of a tree.
Now turn your mind to the truly improbable fact implied by Big Bang
theory. Once, about 13.7 billion years ago, our whole Universe must
have been Planck-scale. Reverse its current expansion and we would see
it shrink back to this size. So for the first 10-43
seconds of its
existence, all the material which makes up our Universe would have been
crammed into a space just 10-33 cm across. And
as a micro-realm, it
would have been completely governed by quantum rules (or so seems a
reasonable assumption say physicists). This being the case, then why
with quantum logic couldn't the entire Universe simply have blipped
into existence as some kind of vacuum fluctuation?
The books would certainly balance in a surprising way. One of the
remarkable features of our Universe is that it appears to have an exact
match between the motions of its masses and the pull of its gravity.
Nothing sits still in this Universe. Atoms and stars bat about. This
weight of mass, this kinetic disorder, represents a positive energy.
Stuff gets scattered messily across an ever widening space as lumps
bump and bounce, collide and repel. But each mass also creates its
portion of gravitational attraction. And gravity has the exact opposite
effect in that it wants to order the Universe, to clump all matter and
bring it into a shared state of rest. So there is an
inter-galactic battle going on between the forces of order
and disorder, agglomeration and dispersal, concentration and dilution,
contraction and expansion.
It as if the Universe was created by a splitting of the seams of a
state of nothingness. The positive energy of all its hurtling mass is
perfectly matched by the negative energy of all its gravitational pull.
So overall our Universe hasn't cost anyone anything to produce! If
eventually the whole Universe were to recollapse into a blob, then into
a Planck-scale point, due to the effects of gravity, then all that
chaotically moving mass would become still again, trapped in a single
super-dense pinprick like it was at the Big Bang. A brief rent in the
fabric of cosmic nothingness would have healed itself. The +1 of all
that motion and the –1 of all that gravity would have
self-annihilating like a virtual particle pair, leaving no trace that a
Universe had ever existed.
The fact that all the complex structure of the Universe neatly adds to
zero is astounding. It means you only need to borrow the ingredients to
construct a Universe for a quantum moment or so. However
science’s first stab at a quantum blip theory of cosmogenesis
ran into a few problems. In particular, a pretty sizeable blip seemed
needed to begin a Universe as large as ours.
The Universe contains a fair bit of energy and mass (energy and mass,
of course, being essentially two sides of the same coin according to
Einstein's equation, E = mc2, which describes how much of one converts
into the other). Estimates of how much vary. We are hampered because
the speed of light puts a strict limit on how much of the Universe we
can actually see. The observable region of the Universe stretches about
13.7 billion lightyears in each direction. Any further away and there
simply has not been enough time since the Big Bang itself for light to
have reached us from more remote regions of space.
But there are reckoned to be some 1089 particles
in the our corner of
the Universe. This could turn out to be the whole of the Universe
anyway. However some theorists have reason to argue the Universe may be
1023 times larger still. So we could be talking
about a huge chunk of
real estate to appear as a point-sized quantum blip - enough eventually
to construct 10112 particles.
Quantum theory allows us to calculate precisely how likely it is for
such a large fluctuation to occur. Infinitesimally small borrowings
against the zero-ness of the vacuum, like that needed to manufacture
virtual particle pairs, counts as being so probable that the fabric of
space must seethe with such events. Quantum uncertainty makes this
level of jitter quite inevitable. But for a cosmic-scale fluctuation
weighing umpteen gazillion tons, the answer is that the chances are
extraordinarily improbable. Even if you allow that a state of
nothingness could have been hanging around indefinitely, the odds
against a Universe-size blip are about equally infinite.
There was another headache for the quantum cosmologists. Why would a
momentary rent in the fabric of nothingness persist and even grow? Any
split into the positive energy of motion and negative energy of
gravitational attraction ought to have collapsed as soon as it
occurred. With so much mass confined to a Planck-sized point, the great
weight of its own gravity ought to have prevented it ever expanding.
That is what happens with a black hole. Indeed, the bigger the quantum
blip, the faster it should have buckled itself back out of
existence.
the ultimate free lunch
Skip forward a decade to the 1980s. Cosmologists such as Alan
Guth and
Andrei Linde discovered a mechanism that could solve all these problems
and more, allowing the entire Universe to be created from a quantum
fluctuation amounting initially to not much more than a teaspoon of
matter.
Dubbed inflation, the idea was that particles of force and matter are
not themselves primal but instead condense out of a more basic state of
being, an ur-substance, called an inflaton field. This field, also
known as the false vacuum, is special in being absolutely featureless
and yet pregnant with an incredible density of energy. It would have no
particles or wavelets to betray its presence. However it would still be
1065 times as dense as something we think of as
incredibly dense such
as the nucleus of an atom.
Just to remind you, it is 10-13 orders of
magnitude to reach the realm
of the atom and 10-33 to hit the Planck scale.
So 1065 is dense indeed
compared to any kind of matter with which we are familiar.
Anyway, the inflation theory goes that a quantum blip might have thrown
up a tiny expanse of false vacuum, this featureless yet incredibly
potent field. The initial fluctuation may itself have only amounted to
the equivalent of a teaspoon of matter. But one of the novel properties
of this inflaton material is that it is internally repulsive. It pushes
against itself. And so it inflates. Indeed it inflates at an
exponential rate as the bigger it grows, the more of it that exists,
and thus the greater the total amount of repulsion it must experience.
Another feature of the inflaton field is that it is unrestricted by the
usual speed limit of the speed of light. The field has no particles and
is not itself attempting to move across a space. Instead it is the
creation of a space itself. So the field can just keep accelerating,
growing faster and faster as its internal repulsion keeps building.
Estimates of the actual expansion rate vary according to different
versions of inflation theory, but some cosmologists say the initial
scrap of false vacuum grew to about the size of a grapefruit in just
10-35 seconds. Others calculate it is a tad
larger by this
stage....more like 1010[12] cms across, or 10 to
the power of a trillion!
All right, stop laughing there at the back of the class. The numbers do
get a little ridiculous. But we are talking about the currently
accepted wisdom in mainstream cosmology. And most inflation theorists
now think the higher estimate to be the more likely. So let’s
consider what may be the gob-smacking truth.
Remember that the entire visible Universe, a stretch of space large
enough to contain 100 billion galaxies each with about 100 billion
stars, is just 1028 cms across. Yet inflation
theory says that even in
the first billion-trillion-trillionth of a second of its existence,
before there was time for anything at all to have happened, the spatial
extent of the Universe may have already grown quite inconceivably,
huge.
Much actually depends how long the inflationary period actually lasted.
The theory says an inflaton field is essentially unstable and so
collapses almost instantly. In the blink of an eye. But if it also
happens to be doubling in size every 10-37
seconds, then lingering just
a few extra trillionths of a second before collapse would make a
tremendous difference to the final extent of whatever was being created.
Drilling down, it takes us 13 orders of magnitude to hit the atomic
realm and 33 to hit the quantum. Building up, it is only 28 orders of
magnitude up to the whole of the visible Universe but perhaps trillions
to encompass the entire sweep of a heated moment of creation.
Putting aside the size issue for the moment, inflation achieves three
vital things for the Big Bang model. First it turns a very small amount
of matter, about a teaspoon, into an immense amount.
When any ordinary physical field is stretched out in space, its mass
and energy are of course diluted. Spread something out and obviously it
gets thinner. But because the inflaton field is featureless - it lacks
the particles or ripples to make one direction look any different to
another - the energy density at each point of space remains constant.
There is no dilution at a point in space as the field expands because,
well, there are no proper points in space. At least this is how the
mathematics pans out. And if true, then there is no problem spinning an
initial teaspoon of material into enough material to manufacture at
least 1032 stars.
A second vital role played by inflation would have been to separate
matter from its gravity. As said, the pull of gravity ought to have
prevented a quantum blip of mass from ever being anything more than an
immensely dense point. Not even a teaspoon lump could have escaped its
own gravitational attraction. Yet the featureless inflaton field held
matter in suspension, as it were. There were no particles yet, just a
trapped, latent, field of naked energy.
So gravity did not have anything to act upon until inflation ended and
actual particles began to condense out of the collapsing inflaton
field. And by then, the cat was out of the bag. The Universe was so
physically large – and more importantly, so messily spread
out – that gravity could not cave it all in again. Gravity
could certainly stir the brew. The negative energy represented by
gravity could begin to tug on all the countless particles, affecting
them in their crashing-about motions. However the essential step of
forging a space in which things could happen, a history could develop,
had already been taken.
The third trick achieved by inflation would have been to make space
look flat. Curious as it may seem, the shape of the Universe is most
probably circular – a bubble of spacetime with no joins or
edges. Well perhaps not so curious as it is just the same in three
dimensions as it is for the 2D surface of the earth. If the earth were
flat as the ancients believed, then it would either have to extend as a
plane to infinity or have a sudden edge where the oceans and any
unlucky ships tumbled over into an abyss. As we know, the earth is a
sphere and if we travel in a “straight line” far
enough, we could come back and tap ourselves on the shoulder.
In the same way, it makes most sense if our Universe is both finite and
infinite because it is a closed inflating hypersphere – a
sphere with a 3D “surface”. Strike out in any
direction, travel for long enough, and you should be able to come back
and tap yourself on the shoulder.
The idea of a hyperspherical Universe has been popular for over a
century. However the trouble is that space doesn't look curved. As well
as can be measured - which is to a great many decimal places - it
appears dead flat. Of course, if the Universe really was a hypersphere,
we would expect to see the same stars twinkling at us from opposite
sides of the night sky. The light would curve to reach us from both
directions. Yet there is no hint of this (as yet).
Inflation provides a highly convenient explanation for the flatness
problem. It says the Universe is simply too large for us to be able to
detect its curvature. If it is anything like 1010[12]
cms in extent, then
light or anything else could never hope to make the round journey and
would always appear to travel in infinite straight lines.
the breaking of inflation
So with a magician’s flourish, not one, but two fat
rabbits
have been pulled out of the hat. A quantum blip can be relied upon to
get a something to spring from nothing. Quantum logic confounds
ordinary logic. And then the inflation mechanism stretches this blip to
immense size before it can snuff itself out in some self-cancelling
way. As cosmologists frequently quip, the Universe was the ultimate
free lunch.
Science still has to prove that inflation actually happened. One kind
of evidence would be if the latest generation of particle colliders -
the giant atom smashers at laboratories such as CERN in Switzerland -
catch sight of the Higgs boson, a super-massive particle believed to be
associated with inflaton-like fields.
Astronomers are also poring over satellite pictures of the cosmic
background radiation, the afterglow of the Big Bang, hoping to pick up
the faint ripple of gravity waves predicted by inflation theory. Yet
even if the story on inflation is not completely nailed down, there is
still high confidence that something very much like it must have
occurred as it so neatly resolves many of the questions surrounding the
Big Bang.
Right, we have a quantum blip. We have inflation. The next important
event in the free lunch tale of the Big Bang is the big condensation -
the decay of the inflaton field and the release of a flood of particles
spawned from its immense latent energy.
The inflaton field was a wodge of naked, unoriented, energy. It was
featureless, utterly symmetrical, looking the same in every direction.
A magnetic field, or any other kind of force field, betrays its
presence because it is oriented in some direction. It has gradients
that lead from high to low, or positive to negative. There is a
structure, some kind of slope, that makes one part of the field
different to the next. But regions within the inflaton field did not
point in any particular direction. Instead – according to the
mathematical models – they pointed chaotically in all
directions.
Like the milling motion of a confused crowd, the result was a space
completely filled with a super-dense intensity of energy – a
potential to do something – but with no cohesive organisation
to allow anything actually to happen or change. This is the hallmark of
chaos, restless action on all scales without meaningful
consequence. But the same mathematical models say this kind
of unoriented state is deeply unstable and would have collapsed almost
immediately into a state of orientated order, even if the choice of
orientation would have been completely random.
The best example to understand this breaking of the symmetry of the
inflaton field is the magnetisation of an iron bar. Each atom in a lump
of iron has its own magnetic pole - a north and south created by its
spinning electric charge. In an ordinary bit of iron, all the atoms are
pointing randomly so overall the bar has no magnetic field. The chaotic
arrangement in all directions averages out to a zero direction and the
energy represented by the many small magnetic fields remains hidden.
However if you heat the bar to release the iron atoms from their
crystalline lattice, allowing them to swivel freely in a semi-fluid
state, and then cool them just slowly enough, then suddenly all the
individual atoms can line up. Nudged by their magnetic fields, the
atoms will align with their nearest neighbours.
The workings of chance means that there will always be some seed - a
fluctuation - to get things going. After all, every effect needs its
triggering cause doesn’t it? In a bar of trillions of atoms,
there will always be a few places where a number of atoms are
reasonably in alignment simply by accident and these will exert just
enough of an influence to recruit a few neighbours. These will do the
same in turn, until there is a snowballing chain reaction. Swiftly -
exponentially - a decisive orientation will spread across the whole
bar.
The direction in which the field ends up pointing will be random as it
was originally a matter of luck which way the seed atoms were faced.
But all the atoms will find themselves trapped into some definite
direction as the bar cools. Well almost all. Depending on the swiftness
of the cooling, pockets of atoms might get caught facing in odd
directions. Yet overall the symmetry of the iron bar will have been
broken and through a process of self-organisation or emergence it will
display a new macroscopic state of order.
This is exactly the way the inflaton field is imagined to have cracked.
After 10-35 seconds, driven by its own internal
repulsion, the field
had grown to somewhere between the size of a grapefruit and 1010[12]
cms. The trapped energy with a density of 1065
times the core of an
atom represented a tension waiting to be dispelled. But there was no
prevailing direction to allow such a change to happen.
However as soon as the inflaton field grew reasonably large it was
guaranteed that due to sheer chance some parts would be enough in
alignment to plant the seed for its rapid decay. In fact the size of
the field means that seeds must have occurred all over the place at the
same instant and so the inflaton field would have erupted into swirling
turbulence as every emerging patch of order fought to align itself as
best it could with its local neighbourhood.
At exponential speed, some general state of orientation would develop
that satisfied all these competing demands. But in the process, the
Universe would have been left with a lot of trapped knots of energy,
point-like inhomogeneities, at the boundaries wherever different parts
of the crumbling field had had to twist themselves into a common
direction. In inflation theory, these knots became the fundamental
particles.
So as far as it could, the inflaton field dispelled its trapped energy
by becoming orderly. It went from the featurelessness of energetic
disorder, in which its locations pointed randomly in all directions, to
a new kind of featurelessness where its locations pointed in a common
direction. However the turbulent nature of the process meant that the
field could not collapse into complete smoothness. The high energy
false vacuum became the "zero energy" true vacuum. But this empty space
was left pockmarked with hard points of matter - knots drawn tight with
no means of undoing themselves and thus dispersing the last remnants of
the inflaton energy.
Actually, one further step was needed to allow the turbulent energies
to dissipate and leave behind a pockmarked state of order. While the
whole Universe was just an inflaton field, there was of course nowhere
for any pent-up energy to go. The total size of the inflaton bubble was
expanding exponentially, yet the new terrain was just as
“hot” and allowed no room for cooling.
Fortunately however the beginnings of an alignment did have a secondary
feedback effect on the rate of expansion of everything. In fact it
brought matters nearly to a screeching halt. For as soon as parts of
the inflaton field started to cohere in some orderly fashion, they also
began to lose the internal repulsion that had been driving them apart.
The inflationary pressure simply evaporated.
Importantly, the Universe continued to grow, but now only at the slow
and steady rate of the speed of light. The crumbling of the inflaton
field was making particles, and these particles were the new mechanism
for manufacturing growth. As they flew apart, they made the Universe an
enlarging space. But instead of the Universe accelerating away from
itself, doubling in extent every 10-37 seconds,
as it had during the
inflation period, now there was only a sedate, even paced, expansion at
300,000 kilometers per second.
Yet tame though this new rate might be, it did serve the purpose of
making the kind of “empty” space in which the
Universe could begin to cool. During inflation, there was only more hot
ground to add to the existing hot ground. Once there was a crumbling
into the structure of particles flying about a void, the raging energy
could spread out and dilute.
It is a marvellous tale – though the logic is perhaps a bit
chicken and egg. The halting of inflation produced a flood of particles
and it was this flood of particles that allowed the halting of
inflation. However think of the process as ratcheting rather than
circular, an open spiralling development rather than a closed causal
loop.
The essence of symmetry-breaking is the fracturing of
“nothingness” into two matching halves –
two halves that will always add neatly back to zero. So the system is
closed, its materials conserved. The whole of what was there before is
still there after. Yet for the two halves to survive, to be more than a
fleeting blip, they must also quickly develop into asymmetrical
outcomes of some kind. They have to be separated in some strong
self-sustaining sense to prevent their immediate recollapse.
With the cracking of inflation, there was the emergence of two such
strong opposites – atoms in a void. As unalike each other as
it was possible to be. Or to describe the same situation another way,
the contrasting energies of motion and gravity – moving
particles and the space between them.
Symmetry-breaking is a “free” way of opening a seam
in nothing to create a reality. But as will become clear, it is the
subsequent moves towards asymmetry that allow the seam to persist and
develop a history. In fact, it was only the swift emergence of yet a
further deeply mysterious asymmetry in the make-up of matter that
allowed particles of mass to survive at all in the cooling post-Big
Bang era – and so to keep the cooling void expanding at the
gentle speed of light.
a baffling asymmetry
The ticking clock of creation has reached a billionth of a
second.
Inflation is over. The Universe has begun its cooling. Space is a
white-hot plasma - a soup of particles with a temperature of some 1013
degrees and a pressure and density to match. The conditions are
extreme, but still quite a step down from the violence of the
inflationary period. The asymmetry of void and particles, motion and
gravity (or void~particles, motion~gravity), is beginning to show. Now
another essential asymmetry reveals itself.
Due to the way the inflaton field crumbled, there ought to be as many
anti-matter particles as matter particles flying about. The zero-ness
of the latent energy should have split evenly to produce as many minus
particles as plus particles.
If we imagine the inflaton field shattering randomly in all possible
directions, then half the matter knots would have formed out of
clockwise twirls while the other half formed out of anti-clockwise
twirls. One way of winding should have been as good as another. And in
the moments following inflation, these particles and anti-particles
would find themselves wandering about in a very crowded space. Each
right-hand twirl could only run straight into a left-handed twirl and
mutually annihilate. The two forms of matter would unravel each
another, releasing their combined energies as a burst of light and
heat.
Indeed, this is what began to happen. The newborn particles started to
annihilate with a vengeance. It looked like they were only going to be
able to preserve the dissipating energy of the inflaton field for a
beat before having to give it up. And so the Universe became ablaze
with the radiance of its fast-vanishing mass - a phase known as
reheating.
But then something odd occurred. For some reason there was a fractional
imbalance in the numbers of the two varieties of particles, an
asymmetry in their otherwise perfect symmetry. For every 300 million
anti-matter particles, there was about one extra matter particle. And
so after every pair of particles that could meet and annihilate had
done so, there was still a tiny residue of material left. One in 300
million matter particles survived - enough lingering mass to make the
planets, stars and galaxies that now populate the vast generally-empty
expanse of our Universe.
The explanation for this vital asymmetry has baffled cosmologists ever
since it was discovered in the 1960s. Some felt it might be plain dumb
luck at work. The random way in which the inflaton field decayed might
have just happened to leave behind a few more matter than anti-matter
knots. But calculations have shown that chance alone would struggle to
account for enough left-over mass to make a single star - for the
entire Universe!
Cosmologists have looked for other explanations. Perhaps our Universe
has a symmetrical twin born at the same Big Bang moment in which
anti-matter happens to dominate. In that way, the cosmic books could be
made to balance. But there is no proper answer as yet. And the
discomforting air of flukiness starting to the intrude into the cosy
story of the Big Bang does not end there. A perhaps even more
improbable slice of dumb luck comes next.
