The
Myth of Pattern
March 17, 2009
From Dan Dennett (http://en.wikiquote.org/wiki/Daniel_C._Dennett):
"As Akins observes, it is not the point of our sensory systems that they should detect "basic" or "natural" properties of the environment, but that they should serve our "narcissistic" purposes in staying alive; nature doesn't build epistemic engines."
I take this to mean that our brains didn't evolve to understand Nature. They evolved to help us survive. If a brain full of delusional simulations helps us survive, its genes will succeed. We can't count on our brains to tell us the truth.
December 13, 2006
Found this speech by Paul Davies that relates to this discussion. I disagree with him.
http://www.firstthings.com/ftissues/ft9508/davies.html
“It has become fashionable in some circles to argue that science is ultimately a sham, that we scientists read order into nature, not out of nature, and that the laws of physics are our laws, not nature's. I believe this is arrant nonsense. You would be hard-pressed to convince a physicist that Newton's inverse square law of gravitation is a purely cultural concoction. The laws of physics, I submit, really exist in the world out there, and the job of the scientist is to uncover them, not invent them. True, at any given time, the laws you find in the textbooks are tentative and approximate, but they mirror, albeit imperfectly, a really existing order in the physical world. Of course, many scientists do not recognize that in accepting the reality of an order in nature-the existence of laws "out there"-they are adopting a theological world view. Ironically, one of the staunchest defenders of the reality of the laws of physics is the American physicist Steven Weinberg, a sort of apologetic atheist who, though able to wax lyrical about the mathematical elegance of nature, nevertheless felt compelled to pen the notorious words, "The more the universe seems comprehensible, the more it also seems pointless."
It hurts his case to use Newton’s gravity as an example of a “really out there not just in our minds” example. GR replaced Newton’s gravity, showing that Nature doesn’t exactly follow the inverse square law. I don’t think science is a sham. I just don’t think any of our laws really exist in the world “out there”. I think we invent laws, rather than discover them. The pursuit of ever-better theories is still worthwhile and practical, even if we’re not glimpsing the mind of god. I agree with Davies that believing in an order of nature is an act of faith that many scientists share. Einstein betrayed this attitude many times. Nothing wrong with it, but it’s not purely scientific.
Does it matter? Not to everyone. You can do good science either way. It matters to epistemologists. I like to know if I’m fooling myself!
September 20, 2005
I was humbled to find this entire essay summed up in one sentence here: http://www.thebigview.com/spacetime/index.html under Open Questions.
3. Like any form of knowledge, physics represents not the world, but our ideas of the world. The question arises whether our ideas converge with ultimate reality, or whether this convergence is an illusion.
March
16, 2004
Einstein: "Physical concepts are free
creations of the human mind, and are not, however it may seem, uniquely
determined by the external world. In our endeavour to understand reality
we are somewhat like a man trying to understand the mechanism of a closed watch.
He sees the face and the moving hands, even hears it ticking, but he has no way
of opening the case. If he is ingenious he may form some picture of the
mechanism which could be responsible for all the things he observes, but he may
never be quite sure his picture is the only one which could explain his
observations. He will never be able to compare his picture with the real
mechanism and he cannot even imagine the possibility of the meaning of such a
comparison."
Niels
Bohr: "It is wrong to think that the task of physics is
to find out how nature is. Physics concerns what we can say about nature"
Amada
Peet: "You can never prove that a theory of nature is correct.
All you can prove is that it's the best theory you have that satisfies your
theoretical consistency and describes the real world to the accuracy that we can
test it." (Full text here.)
This
is a draft of an essay I've been formulating for years now. I’ve just
finished reading several of Stephen
Hawking’s books about physics, cosmology and the fate of the universe.
I love reading his work because he isn’t lost in the scientific
religion. He has a broad enough
intellect to realize that science is simply a description of the world, and
insofar as it corresponds with observation, it is extremely useful.
He is the most eminent scientist I know who has admitted that there is no
guarantee that we can apprehend the universe.
Even so, “seeing the mind of God” is very dear to him and he proceeds
on the premise that it might be possible, and if it isn’t, well, that’s very
interesting to know, too. Brian
Greene touches on these issues in his preface to The Fabric of the Cosmos
and admits there are perceptual hurdles to understanding the universe.
Then, in the noblest scientific spirit, he vigorously proceeds to do the best he
can.
The
first issue is whether the universe is reducible to laws.
This is so basic that it rarely is discussed or questioned.
We are raised hearing about Newton’s
Universal Law of Gravitation only to learn later that errors were found and
Einstein came up with a better description.
This made us wonder if Einstein’s
General Relativity would someday be proved wrong. Well, it already has. At
very high energies, we know it breaks down, so it’s at least incomplete.
Now, the quest is on for a theory of Quantum
Gravity which will resolve these issues.
So, what does it mean to have Laws if they can change? The usual answer is that we just haven’t discovered the
Real Laws yet. What’s seldom
mentioned is the possibility that there aren’t any such laws.
Many assume that the universe obeys
laws, as if it is sentient, thinking about its next move.
It’s a perfectly reasonable possibility that the universe simply is,
and might be different everywhere.
So the question should be can we find out if
there are universal laws? Setting
out with the assumption that there are universal
laws is delivering the verdict in advance.
Hawking admits that we can’t prove that universal laws exist but holds
to the hope that they do. He quotes
the famous scenario wherein a drunk, having lost his keys at night, looks for
them under a lamp post. They might
not be there, but it’s the only place he can look.
The
second issue is whether the physical phenomena we see around us on Earth are the
same throughout the universe. This
assumption is fundamental to science and is fairly well supported by
astrophysical observations, analysis
of light spectra, etc. But we
only have light from the visible universe, that part which is close enough for
light to have traveled to us since the universe began (our light horizon).
So, we can only speak about that for which we have data.
This ratio of acquired data to the total amount of data in the universe
is, of course, infinitesimal. Further,
it appears that normal matter and energy account for less than a third of what
is out there (or General Relativity is wrong), leading most scientists to
postulate dark matter and dark energy to make up the difference.
If these exist, then not only do we not have a full understanding of
known particles, we haven't even identified what most of the universe is made
of. Thus, we base our Laws of
Nature on a vanishingly small sample. Hawking
deals with this in his usual positivist philosophy, which I embrace, that it’s
all we have, so we should make the best of it.
Further, a theory is “correct” if it agrees with known data.
Here is where I differ with the “mind of God” suggestion, that
science is a discovery of how the
universe operates, rather than an after-the-fact, approximate description of
purely human origin.
As
an example, Hawking himself has been credited with “discovering” Hawking
radiation, the putative quantum emissions from black holes.
I would instead call it a prediction, since Hawking radiation exists only
in the mathematics and thought experiments of many of the world’s top
physicists. Hawking radiation has
never been detected and it is unclear if it will ever be detectable.
This lack or testability is sometimes a death knell for a theory (as it
once was for string theory), but Hawking’s reputation seems to have overcome
the lack of testability. Moreover,
Hawking describes ways in which black hole emissions might be detected and if
they are detected, then I would concur that they had been discovered.
This pattern of prediction and discovery has great precedent in the
Standard Model, so Hawking is on firm ground.
Here, it is just another example of people confusing scientific theories
with reality. Maps are classic examples of this confusion. Maps
represent land area in compact form by omitting details. We are so
comfortable using them that some people think that the Mississippi river flows
to the south1 and the north pole is at the top of the world.
For
the moment, let’s sum this up as the following two postulates:
1.
The universe is definable according to laws which only need to be
discovered.
2.
Local and distant phenomena obey the same laws.
There
is a concept lurking in this discussion that requires our attention:
sameness. Physicists call
two particles equivalent if they have the same quantum numbers of spin, charge,
parity, etc. So, two particles are
the “same” (except for location) if these values are the same within
measurable accuracy. The Standard
Model classifies particles and has reduced all known phenomena to 6 quarks
(up, down, charm, strange, bottom and top), 6 leptons and some force-carrying
particles. This is considered a
huge accomplishment, since, theoretically, the entire universe (ignoring
gravity) can be described by the interactions of this small number of particles.
But are all up quarks the same? Our
positivist approach says that if all our data says they are the same, then it is
useful to consider them such. But
now, we have completely left behind the notion that science explains the
universe. It is only an approximate description within the
limits of the data. Perhaps all up
quarks are not the same, and perhaps, if we could zoom in on them like zooming
in on the crowd at a football game, we might see that they are all individuals.
We have no data to support this, but we know that data at these sizes is
hard to come by and we can’t rule it out. Because viewing smaller sizes
requires higher energies, there is a lower limit to what we can investigate
called the Planck limit.
It is humbling to think that there could be myriad layers of smaller and smaller
forms that are intimately within us yet beyond observation. This is the
opposite of the light horizon issue. Macroscopic objects such as
snowflakes, as any school child knows, are never exactly the same, but we are in
the habit of ignoring small differences to make the world more graspable.
This is deadly serious for scientists, whose purpose is to construct a
consistent theory of the universe. Indeed,
this is what is causing the current crisis in physics, the fact that General
Relativity and Quantum Mechanics can’t both be right at very high energies and
very small sizes. We can’t ignore
the small differences anymore, because under these conditions, they’re not
small.
Let’s
return to our normal size scale and talk about sameness again.
We often talk about the sun rising in the east and setting in the west,
even though we know that the exact position is different every day.
So, we say that on March 21 of each year, the sun is in the same position
in the sky. Well, not exactly,
since the earth precesses, the north pole won’t point at Polaris forever.
Oh, and March 21 isn’t exact, since the year is 365.242 (give or take)
days long, so we need a leap day every four years (and leap
seconds once in awhile), except each century (and excepting that
every 400 years). Whew, we’re
wearing ourselves out trying to impose the pattern called the year on the
motion of the earth and the sun. This
is no problem as long as everyone knows that there really is no such thing as a
year, that the earth and the sun don’t care a bit about our calendar and that nothing
ever repeats exactly as the earth goes around the sun.
(Hawking begins one of his chapters this way:
"I was born....exactly 300 years after Galileo's death."
Exactly? I wonder if he
accounted for leap years. And leap seconds.)
The
circle was once considered the perfect shape, so everyone tried to make sure
that heavenly bodies went in circles around the earth, and, later, that the
earth went in circles around the sun. The
problem was that the earth didn’t care a bit about this argument and kept
doing its thing. As better
measurements were made, adjustments to this theory (the infamous
epicycles2) were made to try to salvage it.
Eventually, the theory became unwieldy and the paradigm shifted to a
simpler, more elegant theory without all the fine-tuning of the epicycles.
First came Newton’s Gravity, then Einstein’s General Relativity.
These theories were more satisfying because they seemed more natural
without all the baggage required by the previous theory and they agreed better
with observation. Scientists and mathematicians frequently refer to elegance and
simplicity when developing theories. I’m
not sure why we feel one thing is more elegant than another, but we have no
evidence the universe shares our taste. The
actual Theory of Everything could be ugly by our standards or there might not be
one. Some shudder at that prospect,
but if our quest is understanding, wouldn’t this be just as beautiful a
result, if it were true?
Now,
let’s return to the two previous notions:
1.
The universe is definable according to laws which only need to be
discovered.
2.
Local and distant phenomena obey the same laws.
Both
of these principles rely on the notion of sameness, that the number of possible
configurations of matter and energy is limited and that events can be
equivalent. We usually refer to
sameness as pattern, which I define
for our purposes here as a repeating form.
Hydrogen atoms are usually considered a pattern, since their
configuration of one proton and one electron is the same as every other hydrogen
atom. We therefore treat them as
interchangeable. We know, however,
that hydrogen can absorb and emit light and bond with other atoms but we still
call it a hydrogen atom through all these changing behaviors.
What then, is the hydrogen atom? Isn’t
it the same as the “year” we discussed earlier?
Since it has so many forms and since it is vibrating and changing every
instant, it seems that a “hydrogen atom” is just a convention, a term for an
image in our minds that we all more or less agree on.
And the real hydrogen atom
“out there” is in a unique and perhaps unknowable state. Spectral
analysis tells us that there are hydrogen atoms floating in intergalactic space
right now, and there are some in the atmosphere on earth.
But are they identical? Of
course not. Any two hydrogen atoms
that you could compare would differ in some way, at least in location.
The same may be true of quarks and leptons.
If we have lost the innocent notion that two things can be the same, then
the larger idea of laws governing them must be abandoned, since we can’t even
put things into categories or say that two systems are equivalent and thus
should evolve in the same way. So,
our first postulate is dead and, of course, the second becomes moot.
Brian Greene, in The Fabric of the Cosmos, p. 439, addresses this issue: "According to quantum mechanics, every electron in the universe is identical to every other, in that they all have exactly the same mass, exactly the same electric charge, exactly the same weak and strong nuclear force properties, and exactly the same total spin.....In the same sense, every up-quark is the same as every other, every down-quark is the same as every other, every photon is the same as every other, and so on for other particle species." The point is that there may very well be differences that we can't detect, so we can't rule them out. Further, we know that each particle has a unique location in spacetime, so if we consider the context of each particle and how it interacts with other particles, then each particle is undeniably unique by virtue of its location. Greene minimizes this factor, perhaps because he is from the Western reductionist tradition which aims to explain the universe with a finite set of laws which would provide a unified explanation for all events. This bias is so influential that it is rarely pointed out, except by philosophers. Physicists simply agree that if you can't measure a difference between two things, then they are for all practical purposes identical. They then invoke another article of faith, that what happens here should happen over there. We have lots of evidence to support the universality of physical laws, but we can't prove that all particles everywhere interact the same way. When these two biases are added together, they undermine any Theory of Everything that could be proposed.
Smolin
takes a different approach. He acknowledges that no two things can be the
same, as noted by Leibniz in his identity of the indiscernible axiom.
From The Life of the Cosmos, p. 220: "While each proton
has the same charge and mass as every other, each is different, because each
occupies a different place. Each elementary particle has a unique relation
to the whole." Thus, if every particle is unique, the search for laws
in the traditional sense is
doomed. There is another approach, however, that provides solace.
The universe could be considered as a single event, even a single particle.
If so, the distinctions we see in accelerators, the families of particles in the
Standard Model, may just be "frozen" or broken symmetries,
coalescences which are not really separate entities at all. This sheds new
light on quantum
entanglement. The issues of whether information is transmitted faster
than light and how strange it is that two particles are linked across space
would be less bizarre if there really is one event, not two as seems apparent to
our reductionist way of thinking. Further research may illuminate whether
the particles in question are really separate at all. This holistic view
also sheds new light on the big bang. Current big bang theory embraces the
notion of unification as we approach the instant of the big bang. It then
invokes symmetry breaking as the mechanism whereby the various forces and
particles froze out of the unified soup. Even though symmetries have
broken, the resulting "pieces" could still rightly be viewed as a
single entity. Thus, any attempt to make sense of their interactions or to
find mass behaviors among them would fail, due to the fact that any grouping
into families or categories would be imprecise.
The
tendency of all science is to generalize and ignore small discrepancies, forcing
nature into compartments that suit our thinking.
This is a very dangerous leaning and the scientific method has built-in
safeguards against it. There is still a strong belief, though, that science can
produce a consistent Theory of Everything.
Many physicists, including Hawking, are well aware of the epistemological
factors in such a quest and admit we don’t know if the universe is graspable.
We must remain aware that generalizing is a convenience for us and has no
bearing on the nature of reality. The notion of pattern rises to the level
of myth because it is so widely accepted without proof, despite massive evidence
against it. It differs from most traditional myths, however, because in
our modern culture the word myth has the connotation of something that
was once widely believed and has now been revealed to be false. Many
people still feel, however, that the patterns we hold in our minds are actually
"out there", that forms actually do repeat in nature. Most people
think that seasons, mountains, bicycles and dogs actually exist as more than
convenient categories. For example, we each know that we eat and eliminate
several times a day, yet we still believe we have a static body.
Over time, we are convinced by the incontrovertible evidence that we are
changing and aging, but we can not be surprised. It is common knowledge
that our bodies are different from moment to moment. Therefore, the only
"body" we have is a mental construct we use, like an index card in a
library's card catalog that refers to a book. Rather than seeing things
directly, we see and have relationships with our thoughts that correspond to
them most of the time. This relates to Plato's
Cave Allegory; the cave is the mind and the shadows on the wall are our
thoughts, but we can't turn around and see the true Forms. As long as we
perceive reality with our brains, we are removed from it and live in an
internally-projected simulation of it. Various mystical traditions address
this issue and seek a more direct experience of reality. This is extremely
interesting and profound, since their investigations hinge on another myth, that
we are separate from the universe we are observing.
Whenever
I look closely enough, I see that what I think in my mind is only an
approximation of an infinitely-varying, always-different universe that is
patternless. It is alarming for
physicists to think that we might as well be amnesiacs, since our memories (past
data) will have no exact bearing on future events.
Hawking investigates to what extent we can predict events given the Uncertainty
Principle and the loss of information in black holes.
Here we posit another factor, the possibility that nothing ever really
repeats at all. The good news is that for most human purposes, approximate
descriptions work very well. For
the lofty purpose of trying to understand the full behavior of the universe they
fail. This certainly doesn’t mean
we should cease trying, because the refinement of approximate theories is
valuable by itself. Hawking does a great job of dissecting this issue and
proposes that, if we live in a universe characterized by what he calls a no
boundary condition, it should be possible to form a consistent explanation
of the universe without appealing to outside agencies such as God. This leaves
us in the hopeful position of eventually finding a Theory of Everything, but
Hawking wisely reminds us that such a theory will only consistently describe how
the universe works, not why it bothered to exist in the first place.
If, however, the universe turns out to have a different geometry, then Hawking
acknowledges it is likely that no such theory will be found.
The
human brain has evolved to allow us to navigate and survive in an unpredictable
environment. Smolin (p. 266)points out that Gell-Mann and Hartle have
proposed that the only reason we perceive the classical world at all is
because natural selection has favored that view. Rather than being a pattern-identifying device,
then, the brain is a pattern generator. It tells us a white lie about reality: that
if something happened one way one time, it might happen that way again.
This is close enough to the truth to help in hunting animals and raising crops,
but it is still a lie. This is easy to see, for example, when we see faces
in clouds. The brain's face-recognition cells are initially fooled and
other senses recognize the error. No one would put clouds and faces in the
same category, but part of the brain does just that. This is why we have
to be extremely careful when we do science. Our brains can perceive
patterns that are not there, and the error is not always as obvious as seeing
faces in clouds. Sometimes, we aren't aware of what our brains are doing.
There are numerous optical illusions that illustrate this. Certain gases
and light outside the visible spectrum don't register in our senses at all.
In other words, we can't trust our brains and we must check what they tell us.
Imagine looking at a cloud and really thinking it is someone's face. This
happens all the time in science. The ether
and the cosmological
constant are two examples of human ideas that may or may not correspond with
reality, but which have been thought to be part of nature at one time or
another. Our thoughts, including our awareness of patterns, can be
perceptual illusions.
The
brain's job is to reduce reality to something manageable, and to reduce the
number of responses we make to it. It does this by selectively ignoring
data that don't fit its invented schemes. If a scheme is close enough to
reality, it will result in improved survival. We have taken the success
of our thought patterns to indicate their veracity. This is fallacious in
the realm of formulating a theory of how the universe works. We are
easily hypnotized by our brains since they have a near monopoly on our personal
realities. Like Gödel's
Incompleteness Theorem in mathematics, though, our own capacity for thought
can lead us to an understanding of the brain's limitations. Many common
sense notions have fallen in the last century as we investigate high energies
and extremely small sizes in physics: time has been found to be relative,
the universe has an infinite number of histories (as Hawking puts it, 'we live
in the most probable of all possible worlds'), we can't know the exact physical
location and momentum of a particle at the same time, etc. Pattern
is another cherished idea that must be seen for what it is, a convenience and a
contrivance having no existence outside our minds.
The
important point, then, is an epistemological one. We must always remember that we live our lives in a neural
matrix constrained by our genetics. We
see a tiny sliver of the electromagnetic spectrum, we sense a thin range of
sounds, pressures, tastes, etc. We extend our senses with instruments but will
always be short on information. Further,
we form this paucity of data into a mental construct that is many times removed
from the universe we are studying. Instead
of connecting us to the outside world, then, our senses are walls which remove
us from it. In
fact, when trying to study the outside world, we really are only investigating
our own perceptual machinery. There
is no way around this. We can only
formulate those theories that our minds can conceive, and the universe cares
nothing about this limitation. When
looking outward, we are really looking into a mirror, so our theories say less
about the universe than they do about our way of thinking3.
In
the movie trilogy, The Matrix, humans were confined in a neural construct
created by machines. This is
actually the case, except we make our own illusion, and the illusion is not
enforced. We are free to keep in
mind that we live in a mental construct and that the universe “out there” is
rich in mystery and variety beyond our comprehension.
1Water flows downward, towards the center of the earth's mass,
regardless of its path along other axes. While its overall path is south,
the Mississippi river meanders in many places, following the topology of the
land, and flows east, north, west and every direction in between. The
Nile's path is predominantly north, but it is always flowing downward.
2Aristotle, Ptolemy and even Copernicus thought circles were perfect and
used epicycles
to patch up their theories. Later, they were proved wrong when it was
"discovered" that the planets move in ellipses. My assertion is
that they don't move in perfect ellipses or any other mathematical construct
exactly. This is, in fact, well known to keepers
of atomic clocks who are regularly taking into account the earth's
deceleration due to tidal effects, etc.
3The holographic principle relates to this point as mentioned by Smolin in The Life of the Cosmos, p. 244: "The quantum state is then not a property of the system it describes. It is a property of the boundary or interface that separates that system from the rest of the universe, including the observer who studies it." In other words, our knowledge of a system is inherently limited and colored by the apparatus we use to study it.