This is a brief interview with Ang Lee, where he talks about his latest movie as well as his career and his philosophy. I've been a fan of Lee ever since I saw The Wedding Banquet and have seen most of his movies, including Crouching Tiger Hidden Dragon, Sense and Sensibility and Brokeback Mountain, all of which illustrate his eclectic interests, extraordinary range and mastery of genres.
I haven't seen The Life of Pi, but I read the book by Yann Martel many years ago, after it won the Booker Prize, and was singularly impressed. Given its philosophical nature, one should not be surprised that Lee was attracted to this story, despite its obvious challenges, both technically and thematically.
This interview reveals, more than most, the relationship between the artist and his art. How his art informs him in the same way it informs his audience. All artists strive for an authenticity that effectively negates the pretentiousness and ego that is so easily obtained, especially with success. Ang Lee demonstrates this better than most.
Addendum: A very good review here.
Philosophy, at its best, challenges our long held views, such that we examine them more deeply than we might otherwise consider.
Paul P. Mealing
- Paul P. Mealing
- Check out my book, ELVENE. Available as e-book and as paperback (print on demand, POD). Also this promotional Q&A on-line.
Tuesday, 18 December 2012
Saturday, 1 December 2012
What’s real?
Eric Scerri, who is a lecturer in chemistry
and the history and philosophy of science at the University of California, Los
Angeles, asks a very basic question in last week’s New Scientist (24 Nov. 2012, pp.30-1): how do we know what’s real?
In the world of physics and chemistry, scientists
deal with lots of unobservables like electrons and photons (we see their
effects) not to mention all the varieties of quarks that can never be seen in
isolation, even in theory. Now an electron, and even a positron, will leave a
track in a cloud chamber which can be photographed, but quantum phenomena are
so anti-intuitive that people are sure to ask: is it real? Where ‘it’ is the
Schrodinger wave function that no longer plays a role once the event in question
is ‘observed’. In fact, an earlier issue of New
Scientist dared to address that very question (28 Jul. 2012, pp.29-31), and
it goes to the heart of the longstanding debate as to what quantum mechanics
really means epistemologically. The truth is that no one really knows.
The fact is that since so much of modern
science, especially the fundamentals that underpin physics and chemistry, is
based on unobservables, it leads people to argue for a form of relativism
whereby anything is valid. This point of view is supported by the belief that
all scientific theories are temporary, given their historical perspective.
The gist of Scerri’s article is a
discussion on the philosophical approach proposed by John Worrall in 1989 (Philosopher
of Science at the London School of Economics) called “Structural Realism”. To quote Scerri: ‘For Worrall, what survives when scientific theories change is not so
much the content (entities) as the underlying mathematical structure (form).’
Scerri gives the example of Fresnell’s
theory of light (involving an aether, 1812) being replaced by Maxwell’s
electromagnetic theory. Worrall
argues that some of Fresnell’s mathematics can be found in Maxwell’s theory,
therefore ‘structurally’ Fresnell’s theory is still sound even if the aether is
not. The same criterion can be applied to Einstein’s theory of relativity
compared to Newton’s mechanics. Newton’s inverse square law for gravity is
still intact in Einstein’s theory and all of Einstein’s equations reduce to
Newton’s when the speed of light becomes irrelevant.
Scerri’s own field of expertise is
chemistry and he’s written books on the periodic table, so, not surprisingly,
that becomes a point of discussion. Dmitri Mendelev published his paper in
1869, when the structure of atoms and all their components were unknown. Most
people are unaware that it wasn’t until the 1920s when Bohr, Heisenberg,
Schrodinger and Pauli were pioneering quantum mechanics that the periodic table
suddenly made sense. It reflects the orbital shells that quantum theory
predicts.
At my country high school, we had a
farsighted science teacher (Ron Gunn) who taught us what all these quantum
shells were (without telling us that it was quantum mechanics) so that we could
make sense of all the properties that the periodic table predicts. As Scerri
points out, the periodic table literally embodies the quantum mechanical
structure of the atom. This is something that Mendelev could never have known
about, in the same way that Darwin didn’t know in 1859 that DNA underpins his entire
theory of evolution.
In fact, Scerri also references Darwin and
DNA as another example of mathematical structure underpinning a theory and
ensuring its continuity a century and a half later. To quote again:
‘But
DNA only takes things so far: to go deeper we need to take a mathematical
direction. DNA determines the sequence of bases, A, T, G and C. This becomes a
question of mathematical combinations… played out during the human genome
project.’
Of course, this does not mean that all
mathematical models determine reality, as Ptolemy’s epicyclic solar system
demonstrates; only the ones that survive scientific revolutions. In this context,
no one knows if string theory will follow Ptolemy or Einstein.
Thursday, 29 November 2012
Stephen Fry proselytises Classical Music
I don't know how anyone can't be a fan of Stephen Fry. In this debate at Cambridge University he's at the top of his form. His analogies are as outrageous as they are comical; his argument is both informative and entertaining. The world is a very lucky place and we are fortunate who live in his time.
I need to acknowledge Sally Whitwell, who embedded it on her site with an appropriate quote taken from his closing words.
I need to acknowledge Sally Whitwell, who embedded it on her site with an appropriate quote taken from his closing words.
Saturday, 17 November 2012
Empirical data confirms climate change already happening for a century
Statistically,
Australia’s temperature has risen approximately 1°C in the last 110 years and the oceans have
risen 15-17 cm in the same period. Spring comes about 2 weeks earlier. If you
don’t believe me then watch this special episode of Catalyst, aired last week
on the ABC: scientific evidence of climate-change, not a left-wing conspiracy.
And if it’s happened here then it’s happened all over the world.
Climate change is only
one symptom of humanity’s unprecedented evolutionary success. The reason so
many people, including numerous politicians, are in denial over this world-wide
phenomenon is because it’s another consequence of infinite economic growth: the
paradigm we are all addicted to, irrespective of political persuasion. Europe
is currently finding out what happens when we reach the limit of consumerism
and it will eventually happen everywhere sometime in the 21st
Century. At some point we can no longer rely on a burgeoning next generation to
maintain a non-sustainable economic growth, yet that’s the great denial; an
even greater denial than the belief that climate-change is a global,
scientifically promoted conspiracy.
Wednesday, 31 October 2012
This is torture and a violation of human rights
About 6 months ago I talked about the need
to change cultural attitudes towards girls from so-called traditional cultures
– specifically, to outlaw arranged marriages without the girl’s consent.
The practice of female genital mutilation, erroneously called female circumcision by those who practice it, is
arguably even more barbaric and more confronting to Western cultural norms.
Even though it is illegal in Australia, many people are reluctant to report it,
such is the cultural divide between those who practice it and those who find it
abhorrent.
If ever there was an argument to be made
against moral relativism, this would have to be one of the most compelling examples.
It also highlights how morality for most people, and most societies, is not
based on objective criteria, as we like to contend, but on long-accepted social
norms.
To prevent this practice requires more than
legal prosecution, but a cultural change of attitude. Fundamentally, it needs
to be recognised for what it is – torture of a pre-adolescent or adolescent
girl. As demonstrated in this video, the people who perpetrate these crimes
justify their actions as fulfilling the girl’s destiny. Like most changes to
social norms this will ultimately be a generational change within the
communities who practice it, not just a change in the law.
Wednesday, 10 October 2012
The genius of differential calculus
Newton and Leibniz are both credited as independent
‘inventors’ of calculus but I would argue that it was at least as much
discovery as invention, because, at its heart, differential calculus delivers
the seemingly impossible.
Calculus was arguably the greatest impetus
to physics in the scientific world. Newton’s employment of calculus to give
mathematical definition and precision to motion was arguably as significant to
the future of physics as his formulation of the General Theory of Gravity.
Without calculus, we wouldn’t have Einstein’s Theory of Relativity and we
wouldn’t have Schrodinger’s equation that lies at the heart of quantum
mechanics. Engineers, the world over, routinely use calculus in the form of
differential equations to design most of the technological tools and
infrastructure we take for granted.
Differential calculus is best understood in
its application to motion in physics and to tangents in Cartesian analytic
geometry. In both cases, we have mathematics describing a vanishing entity, and
this is what gives calculus its power, and also makes it difficult for people
to grasp, conceptually.
Calculus can freeze motion, so that at any
particular point in time, knowing an object’s acceleration (like a free-falling
object under gravity, for example) we can determine its instantaneous velocity,
and knowing its velocity we can determine its instantaneous position. It’s the
word ‘instantaneous’ that gives the game away.
In reality, there is no ‘instantaneous’
moment of time. If you increase the shutter speed of a camera, you can ‘freeze’
virtually any motion, from a cricket ball in mid-flight (baseball for you
American readers) to a bullet travelling faster than the speed of sound. But
the point is that, no matter how fast the shutter speed, there is still a
‘duration’ that the shutter remains open. It’s only when one looks at the
photographic record, that one is led to believe that the object has been
captured at an instantaneous point in time.
Calculus does something very similar in
that it takes a shorter and shorter sliver of time to give an instantaneous
velocity or position.
I will take the example out of Keith
Devlin’s excellent book, The Language of
Mathematics; Making the invisible visible, of a car accelerating along a
road:
x = 5t2 + 3t
The above numbers are made up, but the
formulation is correct for a vehicle under constant acceleration. If we want to
know the velocity at a specific point in time we differentiate it with respect
to time (t).
The differentiated equation becomes dx/dt,
which means that we differentiate the distance (x) with respect to time (wrt
t).
To get an ‘instantaneous’ velocity, we take
smaller and smaller distances over smaller and smaller durations. So dx/dt is
an incrementally small distance divided by an incrementally small time, so
mathematically we are doing exactly the same as what the camera does.
But dx occurs between 2 positions, x1
and x2, where dx = x2 – x1
This means: x2 is at dt duration later than x1.
Therefore x2 = 5(t + dt)2 + 3(t + dt)
And x1 = 5t2 + 3t
Therefore dx = x2 – x1 = 5(t + dt)2 +
3(t + dt) - (5t2 + 3t)
If we expand this we get: 5t2
+ 10tdt + 5dt2 + 3t + 3dt – 5t2 – 3t
{Remember: (t + dt)2 = t2 + 2tdt + dt2}
Therefore dx/dt = 10t dt/dt + 5dt2/dt
+ 3dt/dt
Therefore dx/dt = 10t + 3 + 5dt
The sleight-of-hand that allows calculus to
work is that the dt term on the RHS disappears so that dx/dt gives the instantaneous
velocity at any specified time t. In other words, by making the duration virtually zero, we achieve the
same result as the recorded photo, even though zero duration is physically
impossible.
This example can be generalised for any
polynomial: to differentiate an equation of the form,
y = axb
y = axb
dy/dx = bax(b-1) which is exactly what I did above:
If y = 5x2 + 3x
Then dy/dx = 10x + 3
The most common example given in text books
(and even Devlin’s book) is the tangent of a curve, partly because one can
demonstrate it graphically.
If I was to use an equation of the form y =
ax2 + bx + c, and differentiate it, the outcome would be exactly the
same as above, mathematically. But, in this case, one takes a smaller and
smaller x, which corresponds to a smaller and smaller y or f(x). (Note that
f(x) = y, or f(x) and y are synonymous in this context). The slope of the
tangent is dy/dx for smaller and smaller increments of dx. But at the point
where the tangent’s slope is calculated, dx becomes infinitesimal. In other
words, dx ultimately disappears, just like dt disappeared in the above worked
example.
Devlin also demonstrates how integration
(integral calculus), which in Cartesian analytic geometry calculates the area
under a curve f(x), is the inverse function of differential calculus. In other
words, for a polynomial, one just does the reverse procedure. If one
differentiates an equation and then integrates it one simply gets the original
equation back, and, obviously, vice versa.
Saturday, 29 September 2012
2 different views on physics and reality
Back in July I
reviewed Jim Holt’s book, Why Does the
World Exist? (2012), where he interviews various intellects, including
David Deutsch, who wrote The Fabric of
Reality (1997), a specific reference point in Holt’s interview. I’ve since
read Deutsch’s book myself and reviewed it on Amazon UK. I gave it a favourable
review, as it’s truly thought-provoking, which is not to say I agree with his
ideas.
I followed up Deutsch’s
book with John D. Barrow’s New Theories of Everything (originally
published 1990, 2nd edition published 2007) with ‘New’ being added
to the title of the 2nd edition. The 2 books cover very similar
territory, yet could hardly be more different. In particular, Deutsch’s book
contains a radical vision of reality based on the multiple-worlds
interpretation of quantum mechanics, and becomes totally fantastical in its
closing chapter, where he envisages a world of infinite subjective time in the
closing moments of the universe that, to all intents and purposes, represents
heaven.
He took this ‘vision’
from Frank J. Tipler, who, as it turns out, co-wrote a book with Barrow called,
The Anthropic Cosmological Principle
(1986). Barrow also references Tipler in New
Theories of Everything, not only in regard to the possibility of life
forms, or ‘information processing systems’, existing in the final stages of the
Universe, but in relation to everything in the Universe being possibly
simulated in a computer. As Barrow points out there is a problem with this,
however, as not everything is computable by a Turing machine.
Leaving aside the
final chapter, Deutsch’s book is a stimulating read, and whilst he failed to
convince me of his world-view, I wouldn’t ridicule him – he’s not a crank.
Deutsch likes to challenge conventional wisdom, even turn it on its head. For
example, he criticises the view that there is a hierarchy of ‘truth’ from
mathematics to science to philosophy. To support his iconoclastic view, he
provides a ‘proof’ that solipsism is false: it’s impossible for more than one
person to be solipsistic in a given world. Bertrand Russell gave the anecdote
of a woman philosopher writing to him and claiming she was a solipsist, then
complaining she’d met no others. Deutsch uses a different example, but the contradictory
outcome is the same – there can only be one solipsist in a solipsistic
philosophy. He claims that the proof against solipsism is more definitive than
any scientific theory. However, solipsism does occur in
dreams, which we all experience, so there is one environment where solipsism is
‘true’.
In another part of the
book, he points to Godel’s Incompleteness Theorem as evidence that mathematical
‘truths’ are contingent, which undermines the conventional epistemological
hierarchy. Interestingly, Barrow also discusses Godel’s famous Theorem in depth,
albeit in a different context, whereby he muses on what impact it has on
scientific theories. Barrow concludes, if I interpret him correctly, that the
basis of mathematical truths and scientific truths, though related via
mathematical ‘laws of nature’, are different. Scientific truths are ultimately
dependent on evidence, whereas mathematical truths are ultimately dependent on
logical proofs from axioms. Godel’s Theorem prescribes limits to the proofs
from the axioms, but, contrary to Deutsch’s claim, mathematical ‘truths’ have a
universality and dependability that scientific ‘truths’ have never attained
thus far, and are unlikely to in the foreseeable future.
One suspects that
Deutsch’s desire to overturn the epistemological hierarchy, even if only in
certain cases, is to give greater authority to his many-worlds interpretation
of quantum mechanics, as he presents this view as if it’s unassailable to
rational thought. For Deutsch, this is the ‘reality’ and Einstein’s space-time
is merely an approximation to reality on a large scale. It has to be said that
the many-worlds interpretation of quantum mechanics is becoming more popular, but
it’s not definitive and the ‘evidence’ of interference between these worlds,
manifest in quantum experiments, is not evidence of the worlds themselves. At
the end of the day, it’s evidence that determines scientific ‘truth’.
Deutsch begins his
book with a discussion on Popper’s philosophy of epistemology and how it
differs from induction. Induction, according to Deutsch, simply examines what
has happened in the past and forecasts it into the future. In other words, past
experimental results predict future experimental results. However, Deutsch
argues, quite compellingly, that the explanatory power of a theory has more
authority and more weight than just induction. Kepler’s mathematical formulation
of planetary orbits gives us a mechanism of induction but Newton’s Theory of
Gravity gives us an explanation. It’s obvious that Deutsch believes that Hugh
Everett’s many-worlds interpretation of quantum mechanics is a better
explanation than any other rival interpretation. My contention is that quantum
rival ‘theories’ are more philosophically based than science-based, so they are
not theories per se, as there are no experiments that can separate them.
It was towards the end
of his book, before he took off in a flight of speculative fancy, that it
occurred to me that Deutsch had managed to convey all aspects of the universe –
space-time, knowledge, human free will, chaotic and quantum phenomena, human
and machine computation – into an explanatory model with quantum
multiple-worlds at its heart. He had encompassed this world-view so completely
with his ‘4 strands of reality’ – quantum mechanics, epistemology, evolution,
computation – that he’s convinced that there can be no other explanation,
therefore the quantum multiple-worlds must be ‘reality’.
In fact, Deutsch believes that his thesis is so all-encompassing that even
chaotic phenomena can be explained as classical manifestations of quantum
mechanics, even though the mathematics of chaos theory doesn’t support this. In
all my reading, I’ve never come across another physicist who claims that
chaotic phenomena have quantum mechanical origins.
Despite his emphasis
on explanatory power, Deutsch makes no reference to Heisenberg's Uncertainty Principle
or Planck’s constant, h. Considering
how fundamental they are to quantum mechanics, a theory that fails to mention
them, let alone incorporate them in its explanation, would appear to
short-change us.
Deutsch does however
explain the probabilities that are part and parcel of quantum calculations and
predictions. They are simply the result of the ratio of universes giving one
result over another. This implies that we are discussing a finite number of
universes for every quantum interaction, though Deutsch doesn’t explicitly state
this. Mathematically, I believe this could be the Achilles heel of his thesis:
the quantum multiverse cannot be infinite yet its finiteness appears open-ended, not to mention indeterminable.
Quantum computers is
an area where I believe Deutsch has some expertise, and it’s here that he
provides one compelling argument for multiple worlds. To quote:
When a quantum factorization engine is
factorizing a 250-digit number,
the number of interfering universes will be of the order of 10500…
Deutsch issues the
challenge: how can this be done without multiple universes working in parallel?
He explains that these 10500
universes are effectively identical except that each one is doing a different
part of the calculation. There are also 10500
identical persons each getting the correct answer. So quantum
computers, when they become standard tools, will be creating multiple universes
complete with multiple human populations along with the infrastructure, worlds,
galaxies and independent futures, all simultaneously calculating the same
algorithm. In response to Deutsch’s challenge, I admit I don’t know, but I find
his resolution incredulous in the extreme (refer Addendum 2 below).
Those who have read my
post on Holt’s book, will remember that he interviewed Roger Penrose as well as
Deutsch (along with many other intellectual luminaries). Interestingly, Holt
seemed to find Penrose’s Platonic mathematical philosophy more bizarre than
Deutsch’s but based on what I’ve read of them both, I’d have to disagree.
Deutsch also mentions Penrose and delineates where he agrees and disagrees. To
quote again:
[Penrose] envisages a comprehensible world,
rejects the supernatural, recognizes creativity as being central to
mathematics, ascribes objective reality both to the physical world and to
abstract entities, and involves an integration of the foundations of
mathematics and physics. In all these respects I am on his side.
Where Deutsch
specifically disagrees with Penrose is in Penrose’s belief that the human brain
cannot be reduced to algorithms. In other words, it disobeys Turing’s universal
principle (as interpreted by Deutsch) that everything in the universe can be
simulated by a universal quantum Turing machine. (Deutsch, by the way, believes
the brain is effectively a classical computer, not a quantum computer.) Deutsch
points out that Penrose’s position is at odds with most physicists, yet I agree
with him on this salient point. I don’t believe the brain (human or otherwise)
runs on algorithms. Deutsch sees this as a problem with Penrose’s world-view as
he’s unable to explain human thinking. However, I see it as a problem with
Deutsch’s world-view, because, if Penrose is right, then Deutsch is the one who
can’t explain it.
Barrow is a cosmologist
and logically his book reflects this perspective. Compared to Deutsch’s book,
it’s more science, less philosophy. But there is another fundamental
difference, in tone if not content. Right from his opening words, Deutsch
stakes his position in the belief that we can encompass more and more knowledge
in fewer and fewer theories, so it is possible for one person to ‘understand’
everything, at least in principle. He readily acknowledges, however, that we
will probably never ‘know’ everything. On the other hand, Barrow brings the
reader down-to-earth with a lengthy discussion on the initial conditions of the
universe, and how they are completely up for grabs based on what we currently
know.
Barrow ends his
particular chapter on cosmological initial conditions with an in-depth
discussion on the evolution of cosmology from Newton to Einstein to Wheeler-De
Witt, which leads to the Hartle-Hawking ‘no-boundary condition’ model of the universe. He points out that this is a radical theory, ‘proposed by James Hartle
and Stephen Hawking for aesthetic reasons’, but it overcomes the divide between
initial conditions and the laws of nature. Compared to Deutsch’s radical
theses, it’s almost prosaic. It has the added advantage of overcoming
theological-based initial conditions, allowing ‘…a Universe which tunnels into
existence out of nothing.’
Logically, a book on
‘theories of everything’ must include string theory or M theory, yet it’s not
Barrow’s strong suit. Earlier this year, I read Lee Smolin’s The Trouble With Physics, which gives a
detailed history and critique of string theory, but I won’t discuss it here. Of
course, it’s another version of ‘reality’ where ‘theory’ is yet to be given
credence by evidence.
As I alluded to above,
what separates Barrow from Deutsch is his cosmologist’s perspective. Even if we
can finally grasp all the laws of Nature in some ‘Theory of Everything’, the
outcomes are based on chance, which was once considered the sole province of
gods, and, as Barrow argues, is the reason that the mathematics of chance and
probability were not investigated earlier in our scientific endeavours. To
quote Barrow:
…it is possible for a Universe like ours to be
governed by a very small number of simple laws and yet display an unlimited
number of complex states and structures, including you and me.
Of all the
improbabilities, the most fundamental and consequential to our existence is the
asymmetry between matter and antimatter of one billion and one to one billion. We know this,
because the ratio of photons to protons in the Universe is two billion to one
(the annihilation of a proton with an anti-proton creates 2 photons). It is
sobering to consider that a billion to one asymmetry in the birth pangs of the
Universe is the basis of our very existence.
The final chapter in
Barrow’s book is called Is pi really in
the sky? This is an obvious allusion to mathematical Platonism and the
entire chapter is a lengthy and in-depth discussion on the topic of mathematics
and its relationship to reality. (Barrow has also authored a book called Pi in the Sky, which I haven’t read.) According
to Barrow, Plato and Aristotle were the first to represent the dichotomy we
still find today as to whether mathematics is discovered or invented. In other
words, is it solely a product of the human mind or does it have an abstract
existence independently of us and possibly the Universe? What we do know is
that mathematics is the fundamental epistemological bridge between reality and
us, especially when it comes to understanding Nature’s deepest secrets.
In regard to
Platonism, Barrow has this to say:
It elevates mathematics close to the status of God... just alter the word ‘God’ to ‘mathematics’ wherever it appears and it makes pretty good
sense. Mathematics is part of the world, and yet transcends it. It must exist
before and after the Universe.
In the next paragraph
he says:
Most scientists and mathematicians operate as
if Platonism is true, regardless of whether they believe that it is. That is,
they work as though there were an unknown realm of truth to be discovered.
Neither of these
statements are definitive, and it should be pointed out that Barrow discusses
all aspects of mathematical philosophies in depth.
I think that
consciousness will never be reduced to mathematics, yet it is consciousness
that makes mathematics manifest. Obviously, some argue that it is consciousness
alone that makes mathematics at all, and Platonism is a remnant of numerology
and mysticism. Whichever point of view one takes, it is mathematics that makes
the Universe comprehensible. I’m a Platonist because of both the reasons given
above. I don’t think the Universe is a giant computer, but I do think that
mathematics determines, to a large extent, what realities we can have.
Despite my criticisms and disagreements, I
concede that Deutsch is much cleverer than me. His book is certainly
provocative, but I think it’s philosophically flawed in all the areas I discuss
above. On the other hand, the more I read of Barrow, the more I find myself
aligning to his cosmological world-view; in particular, his apparent attraction
to the Anthropic Principle. He makes the point that the probability of the
critical Nature’s constants’ values are less important than their necessity to
provide conditions for observers to evolve. This does not invoke teleology - as
he’s quick to point out – it’s just a necessary condition if intelligent life
is to evolve.
You’ve no doubt noticed that I don’t really
address the question in my heading. Deutsch’s multiverse and String Theory are
two prevalent, if also extreme, versions of reality. String Theory claims that
the Universe is actually 10 dimensions of space rather than 3 and predicts 10500
possible universes, not to be confused with the quantum multiverse. 20th
Century physics has revealed, through quantum mechanics and Einstein’s theories
of relativity, that ‘reality’ is more ‘strange’ than we imagine. I often think that Kant was prescient,
in ways he could not have anticipated, when he said that we may never know the
‘thing-in-itself’.
It is therefore apposite to leave you with
Barrow’s last paragraph in his book:
There
is no formula that can deliver all truth, all harmony, all simplicity. No
Theory of Everything can ever provide total insight. For, to see through
everything, would leave us seeing nothing.
Barrow loves to fill
his books with quotable snippets, but I like this one in particular:
Mathematics is the part of science you could
continue to do if you woke up tomorrow and discovered the universe was gone. Dave Rusin.
Addendum 1: I've since read John Barrow's book, Pi in the Sky, and cover it here.
Addendum 2: I've since read Philip Ball's book, Beyond Weird, where he challenges Deutsch's assertion that it requires multiple worlds to explain quantum computers. Quantum computers are dependent on entangled particles, which is not the same thing. Multiple entities in quantum mechanics don't really exist (according to Ball) just multiple probabilities, only one of which is ever observed. In Deutsch's theory that 'one' is in the universe that you happen to inhabit, whereas all the others exist in other universes that you are not consciously aware of.
Addendum 1: I've since read John Barrow's book, Pi in the Sky, and cover it here.
Addendum 2: I've since read Philip Ball's book, Beyond Weird, where he challenges Deutsch's assertion that it requires multiple worlds to explain quantum computers. Quantum computers are dependent on entangled particles, which is not the same thing. Multiple entities in quantum mechanics don't really exist (according to Ball) just multiple probabilities, only one of which is ever observed. In Deutsch's theory that 'one' is in the universe that you happen to inhabit, whereas all the others exist in other universes that you are not consciously aware of.
Sunday, 2 September 2012
This one is for the climate-change sceptics
Notice I use the English spelling and not
the American (skeptic) for those who may think I can’t spell (although I’m not
infallible).
Not so long ago, North Carolina passed a bill to ‘bar state agencies from considering accelerated sea level rise in
decision-making until 1 July 2016’. Apparently, this is a watered-down version
of the original bill, which I believe didn’t have the 4 year moratorium. I
learnt about it because it was reported in the Letters section of New
Scientist. What worries me is the mentality behind this: the belief that we
can legislate against nature. In
other words, if scientists start making predictions about sea-level rise, it’s
forbidden. The legislation doesn’t state that sea level rise can’t happen but
that any science-based predictions must be ignored.
This mentality also exists in Australia
where there seems to be an unspoken yet tacit belief that we can vote against
climate-change politically. There is a serious disconnect here: nature doesn’t
belong to any political party; it’s not a constituency. The current leader of
the opposition in Australian Federal politics, Tony Abbott, won his position
(within the Party or Cabinet room) over the incumbent, on this very issue. The
incumbent leader, Malcolm Turnbull, felt so strongly over the moral issue of
human-induced climate-change he put his leadership on the line and lost, by 1
vote (in 2009).
This interview with Climate Central's chief climatologist, Heidi Cullen, from Princeton University, helps to put this issue
into perspective. We don’t live at the poles where evidence of climate change
is most apparent. The signs are there and we need to trust the people who can
read the signs, whom we call scientists. Malcolm Turnbull, who lost his job
over this, made the point that there is something wrong with a society when we can't trust our scientists – they are our brains trust.
In Australia, the sceptics argue that this
is a global conspiracy by climatologists to keep themselves in jobs and maintain
an influx of funding. In other words, as long as they keep maintaining that
there is a problem, governments will keep giving them money, whereas, if they
tell the ‘truth’ the funding will stop. This is so ludicrous one can’t waste
words on it. In Australia, scientists working on climate-change were sent
death-threats, which demonstrates the mentality of the people who oppose it.
Again, there is an irrational-held belief that if only scientists would write
the right reports that tell us climate-change is a furphy, then it won’t happen
– the problem will simply go away.
Addendum: I learnt today (8 Sep 2012) that the NSW government has done something similar: revoked local council laws indicating coastal properties which may be subject to sea-level rise based on IPCC predictions.
Addendum: I learnt today (8 Sep 2012) that the NSW government has done something similar: revoked local council laws indicating coastal properties which may be subject to sea-level rise based on IPCC predictions.
Saturday, 18 August 2012
The Riemann Hypothesis; the most famous unsolved problem in mathematics
I’ve read 3 books on
this topic: The Music of the Primes
by Marcus du Sautoy, Prime Obsession
by John Derbyshire and Stalking the
Riemann Hypothesis by Dan Rockmore (and I originally read them in that
order). They are all worthy of recommendation, but only John Derbyshire makes a
truly valiant attempt to explain the mathematics behind the ‘Hypothesis’ (for
laypeople) so it’s his book that I studied most closely.
Now it’s impossible
for me to provide an explanation for 2 reasons: one, I’m not mathematically
equipped to do it; and two, this is a blog and not a book. So my intention is
to try and instill some of the wonder that Riemann’s extraordinary
gravity-defying intuitive leap passes onto those who can faintly grasp its
mathematical ramifications (like myself).
In 1859 (the same year
that Darwin published The Origin of the
Species), a young Bernhard Riemann (aged 32) presented a paper to the
Berlin Academy as part of his acceptance as a ‘corresponding member’, titled
“On the Number of Prime Numbers Less Than a Given Quantity”. The paper contains
a formula that provides a definitive number called π (not to be confused with
pi, the well-known transcendental number). In fact, I noticed that Derbyshire uses Ï€(x) as a function in an attempt to make a distinction. As Derbyshire points out, it’s
a demonstration of the limitations arising from the use of the Greek alphabet
to provide mathematical symbols – they double-up. So Ï€(x) is the number of primes
to be found below any positive Real number. Real numbers include rational
numbers, irrationals and transcendental numbers, as well as integers. The
formula is complex and its explication requires a convoluted journey into the
realm of complex algebra, logarithms and calculus.
Eratosthenes was one
of the librarians at the famous Alexandria Library, around 230 BC and roughly 70
years after Euclid. He famously measured the circumference of the Earth to
within 2% of its current figure (see Wikipedia) using the sun and some basic
geometry. But he also came up with the first recorded method for finding primes
known as Eratosthenes’ Sieve. It’s so simple that it’s obvious once explained: leaving
the number 1, take the first natural number (or integer) which is 2, then
delete all numbers that are multiples of 2, which are all the even numbers.
Then take the next number, 3, and delete all its multiples. The next number
left standing is 5, and one just repeats the process over whatever group of
numbers one is examining (like 100, for example) until you are left with all
the primes less than 100. With truly gigantic numbers there are other methods,
especially now we have computers that can grind out algorithms, but
Eratosthenes demonstrates that scholars were fascinated by primes even in antiquity.
Euclid famously came
up with a simple proof to show that there are an infinite number of primes,
which, on the surface, seems a remarkable feat, considering it’s impossible to
count to infinity. But it’s so simple that Stephen Fry was even able to explain
it on his TV programme, QI. Assume
you have found the biggest prime, then take all the primes up to and including
that prime and multiply them all together. Then add 1. Obviously none of the
primes you know can be factors of this number as they would all give a
remainder of 1. Therefore the number is either a prime or can be factored by a
prime that is higher than the ones you already know. Either way, there will
always be a higher prime, no matter which one you select, so there must be an
infinite number of primes.
The thing about
primes, that has fascinated mathematicians for eons, is that there appears to
be no rhyme or reason to their distribution, except they get thinner - further
apart as one goes to higher numbers. But even this is not strictly correct
because there appears to be an infinite number of twin primes, 2 primes
separated by a non-prime (which must be even for obvious reasons).
Back to Riemann’s
paper and its 150 year old legacy. Entailed in his formula is a formulation of
the Zeta function. Richard Elwes provides a relatively succinct exposition in
his encyclopaedic MATHS 1001, and I’m not even going to attempt to write it
down here. The point is that the
Zeta function gives complex roots to infinity. Most people know what a
quadratic root is from high school maths. If you take the graph of a parabola
like y = ax2 + bx + c, then it crosses the x axis where y = 0. It
can cross the x axis in 2 places, or just touch it in 1 place or not cross it
at all. The values of x that gives us a 0 value of y are called the roots of
the equation. As a polynomial goes up in degree so does its number of roots. So
a quadratic equation gives us 2 roots maximum but a polynomial with degree 3
(includes x3) will give us 3 roots and so on. Going back to the
parabola, in the case where we don’t get any roots at all, it’s because we are
trying to find square roots of negative numbers. However, if we use i (√-1), we get complex roots in the form of a +
ib. (For a basic explanation see my Apr.12 post on imaginary numbers.) A
trigonometric equation like sinθ can give us an infinite number of zeros and so
can the Zeta function.
If you didn’t follow
that, don’t worry, the important point is that Riemann’s Hypothesis says that all
the complex zeros of the Zeta function (to infinity) have Real part ½. So they
are all of the form ½ + ib. Riemann wasn’t able to provide a proof for this and
neither have the best mathematical minds since. The critical point is that if
his Hypothesis is correct then so is his formula for finding an exact number of
primes to any given number.
In the 150 years
since, Riemann’s Hypothesis has found its way into many fields of mathematics,
including Hermitian matrices, which has implications for quantum mechanics. The
Zeta function is a formidable mathematical beast to the uninitiated, and its relationship to the distribution of the primes was first intimated by Euler.
Riemann’s genius was to introduce complex numbers, then make the convoluted
mental journey to demonstrate their pivotal role in providing an exact result. Even then, his fundamental conjecture was effectively based on
a hunch. At the time he presented his paper, he had only calculated the first 3
non-trivial zeros (non-trivial means complex in this context) and computers
have calculated them in the trillions since, yet we still have no proof. It’s known that
they become chaotic at extremely high numbers (beyond the number of atoms in
the universe) so it’s by no means certain that Reimann’s hypothesis is correct.
It would be a huge
disappointment to most mathematicians if either a proof was found to falsify it
or an exception was found through brute computation. Riemann gave us a formula that
gives us an accurate count of the primes (Derbyshire gives a worked example up to 1 million) that’s dependent on the Hypothesis being correct to specified values.
It’s hard to imagine that this formula suddenly fails at some extremely high
number that’s currently beyond our ken, yet it can’t be ruled out.
Marcus du Sautoy, in The Music of the Primes, contemplates
the Riemann hypothesis in the context of Godel’s Incompleteness Theorem, which
is germane to the entire edifice of mathematics. The primes have a history of
providing hard-to-prove conjectures. Along with Riemann’s hypothesis, there is
the twin prime conjecture I mentioned earlier and Goldbach’s conjecture, which
states that every even number greater than 2 is the sum of 2 primes. These
conjectures are also practical demonstrations of Turing’s halting problem
concerning computers. If they are correct, a computer algorithm set to finding
them may never stop, yet we can’t determine in advance whether it will or not,
otherwise we’d know in advance if it was true or not.
As du Sautoy points
out, a corollary to Godel’s theorem is that there are limits to the proofs from
any axioms we know at any time. In essence, there may be mathematical truths
that the axioms cannot cover. The solution is to expand the axioms. In other
words, we need to expand the foundations of our mathematics to extend our
knowledge at its stratospheric limits. Du Sautoy speculates that the Riemann
Hypothesis, along with these other examples, may be Godel’s Incompleteness Theorem
in action.
Exploring the Reimann
Hypothesis, even at the rudimentary level that I can manage, reinforces my
philosophical Platonist view of mathematics. These truths exist independently
of our investigations. There are an infinity of these Zeta zeros (we know that
much) the same as there are an infinity of primes, which means there will
always exist mathematical entities that we can’t possibly know. But aside from
that obvious fact, the relationship that exists between apparently obscure
objects like Zeta zeros and the distribution of prime numbers is a wonder. Godel’s
Theorem implies that no matter how much we learn, there will always be
mathematical wonders beyond our ken.
Addendum: This is a reasonably easy-to-follow description of Riemann's famous Zeta function, plus lots more.
Addendum: This is a reasonably easy-to-follow description of Riemann's famous Zeta function, plus lots more.
Thursday, 16 August 2012
Sex, Lies and Julian Assange, according to the ABC
With Assange’s status again in the
spotlight, and the British government threatening to revoke Ecuador’s
diplomatic asylum status, using force if necessary, which would be unprecedented
in the modern world, it is worth looking at what all the fuss is about.
Almost a month ago, ABC’s 4 Corners aired
its own investigations of the allegations against Assange initiated in Sweden.
What the programme demonstrates is just how farcical this entire episode is.
Considering he was allowed to leave Sweden
by Sweden’s public prosecutor, you would have to wonder, what changed? Is it a
coincidence that Sweden’s change of mind - complete reversal in fact - came
about when Assange elevated his whistle-blowing campaign against America?
Going by the rhetoric coming out of London,
it’s fairly obvious, no matter what decision Ecuador comes to, Assange will be
extradited to Sweden, and then we will find out if America will finally reveal
its hand.
Saturday, 21 July 2012
Why is there something rather than nothing?
Jim Holt has written
an entire book on this subject, titled Why
Does the World Exist? An Existential Detective Story. Holt is a philosopher
and frequent contributor to The New
Yorker, the New York Times and the London Review of Books, according to the blurb on the inner title
page. He’s also very knowledgeable in mathematics and physics, and has the
intellectual credentials to gain access to some of the world’s most eminent
thinkers, like David Deutsch, Richard Swinburne, Steven Weinberg, Roger Penrose
and the late John Updike, amongst others. I’m stating the obvious when I say
that he is both cleverer and better read than me.
The above-referenced,
often-quoted existential question is generally attributed to Gottfried Leibniz,
in the early 18th Century and towards the end of his life, in his
treatise on the “Principle of Sufficient Reason”, which, according to Holt, ‘…says,
in essence, that there is an explanation for every fact, an answer to every
question.’ Given the time in which he lived, it’s not surprising that Leibniz’s
answer was ‘God’. Whilst Leibniz
acknowledged the physical world is contingent, God, on the other hand, is a
‘necessary being’.
For some people (like
Richard Swinburne), this is still the only relevant and pertinent answer, but
considering Holt makes this point on page 21 of a 280 page book, it’s obviously
an historical starting point and not a conclusion. He goes on to discuss Hume’s
and Kant’s responses but I’ll digress. In Feb. 2011, I wrote a post on
metaphysics, where I point out that there is no reason for God to exist if we
didn’t exist, so I think the logic is back to front. As I’ve argued elsewhere
(March 2012), the argument for a God existing independently of humanity is a
non sequitur. This is not something I’ll dwell on – I’m just putting the
argument for God into perspective and don’t intend to reference it again.
Sorry, I’ll take that
back. In Nov 2011, I got into an argument with Emanuel Rutten on his blog,
after he claimed that he had proven that God ‘necessarily exists’ using modal
logic. Interestingly, Holt, who understands modal logic better than me, raises
this same issue. Holt references Alvin Platinga’s argument, which he describes
as ‘dauntingly technical’. In a nutshell: because of God’s ‘maximal greatness’,
if one concedes he can exist in one possible world, he must necessarily exist
in all possible worlds because ‘maximal greatness’ must exist in all possible
worlds. Apparently, this was the basis of Godel’s argument (by logic) for the
existence of God. But Holt contends that the argument can just as easily be
reversed by claiming that there exists a possible world where ‘maximal
greatness’ is absent’. And ‘if God is absent from any possible world, he is absent from all possible worlds…’ (italics in the original). Rutten, by the
way, tried to have it both ways: a personal God necessarily exists, but a
non-personal God must necessarily not exist. If you don’t believe me, check out
the argument thread on his own blog which I link from my own post, Trying to define God (Nov. 2011).
Holt starts off with a
brief history lesson, and just when you think: what else can he possibly say on
the subject? he takes us on a globe-trotting journey, engaging some truly
Olympian intellects. As the book progressed I found the topic more engaging and
more thought-provoking. At the very least, Holt makes you think, as all good
philosophy should. Holt acknowledges an influence and respect for Thomas Nagel, whom he
didn’t speak with, but ‘…a philosopher I have always revered for his
originality, depth and integrity.’
I found the most
interesting person Holt interviewed to be David Deutsch, who is best known as
an advocate for Hugh Everett’s ‘many worlds’ interpretation of quantum
mechanics. Holt had expected a frosty response from Deutsch, based on a review
he’d written on Deutsch’s book, The
Fabric of Reality, for the Wall
Street Journal where he’d used the famous description given to Lord Byron:
“mad, bad and dangerous to know”. But he left Deutsch’s company with quite a
different impression, where ‘…he had revealed a real sweetness of character and
intellectual generosity.’
I didn’t know this,
but Deutsch had extended Turing’s proof of a universal computer to a quantum
version, whereby ‘…in principle,
it could simulate any physically possible environment. It was the ultimate
“virtual reality” machine.’ In fact, Deutsch had presented his proof to Richard
Feynman just before his death in 1988, who got up, as Deutsch was writing it on
a blackboard, took the chalk off him and finished it off. Holt found out, from
his conversation with Deutsch, that he didn’t believe we live in a ‘quantum computer
simulation’.
Deutsch outlined his
philosophy in The Fabric of Reality,
according to Holt (I haven’t read it):
Life and thought, [Deutsch] declared, determine
the very warp and woof of the quantum multiverse… knowledge-bearing structures
– embodied in physical minds – arise from evolutionary processes that ensure
they are nearly identical across different universes. From the perspective of
the quantum multiverse as a whole, mind is a pervasive ordering principle, like
a giant crystal.
When Holt asked
Deutsch ‘Why is there a “fabric of reality” at all?’ he said “[it] could only be
answered by finding a more encompassing fabric of which the physical multiverse
was a part. But there is no ultimate answer.” He said “I would start with the
principle of comprehensibility.”
He gave the example of
a quasar in the universe and a model of the quasar in someone’s brain “…yet
they embody the same mathematical relationships.” For Deutsch, it’s the
comprehensibility of the universe (in particular, its mathematical
comprehensibility) that provides a basis for the ‘fabric of reality’. I’ll
return to this point later.
The most insightful aspect
of Holt’s discourse with Deutsch was his differentiation between explanation by
laws and explanation of specifics. For example, Newton’s theory of gravitation
gave laws to explain what Kepler could only explain by specifics: the orbits of
planets in the solar system. Likewise, Darwin and Wallace’s theory of natural
selection gave a law for evolutionary speciation rather than an explanation for
every individual species. Despite his affinity for ‘comprehensibility’, Deutsch
also claimed: “No, none of the laws of physics can possibly answer the question
of why the multiverse is there.”
It needs to be pointed
out that Deutsch’s quantum multiverse is not the same as the multiverse propagated
by an ‘eternally-inflating universe’. Apparently, Leonard Susskind has argued
that “the two may really be the same thing”, but Steven Weinberg, in
conversation with Holt, thinks they’re “completely perpendicular”.
Holt’s conversation
with Penrose held few surprises for me. In particular, Penrose described his 3
worlds philosophy: the Platonic (mathematical) world, the physical world and
the mental world. I’ve expounded on this in previous posts, including the one
on metaphysics I mentioned earlier but also when I reviewed Mario Livio’s book,
Is God a Mathematician? (March 2009).
Penrose argues that
mathematics is part of our mental world (in fact, the most complex and advanced
part) whilst our mental world is produced by the most advanced and complex part
of the physical world (our brains). But Penrose is a mathematical Platonist, and
conjectures that the universe is effectively a product of the Platonic world,
which creates an existential circle when you contemplate all three. Holt found
Penrose’s ideas too ‘mystical’ and suggests that he was perhaps more
Pythagorean than Platonist. However, I couldn’t help but see a connection with
Deutsch’s ‘comprehensibility’ philosophy. The mathematical model in the brain
(of a quasar, for example) having the same ‘mathematical relationships’ as the
quasar itself. Epistemologically, mathematics is the bridge between our
comprehensibility and the machinations of the universe.
One thing that struck
me right from the start of Holt’s book, yet he doesn’t address till the very end,
is the fact that without consciousness there might as well be nothing.
Nothingness is what happens when we die, and what existed before we were born.
It’s consciousness that determines the difference between ‘something’ and
‘nothing’. Schrodinger, in What is Life?
made the observation that consciousness exists in a continuous present.
Possibly, it’s the only thing that does. After all, we know that photons don’t.
As Raymond Tallis keeps reminding us, without consciousness, there is no past,
present or future. It also means that without memory we would not experience
consciousness. So some states of unconsciousness could simply mean that we are
not creating any memories.
Another interesting
personality in Holt’s engagements was Derek Parfit, who contemplated a
hypothetical ‘selector’ to choose a universe. Both Holt and Parfit concluded,
through pure logic, using ‘simplicity’ as the criterion, that there would be no
selector and ‘lots of generic possibilities’ which would lead to a ‘thoroughly
mediocre universe’. I’ve short-circuited the argument for brevity, but,
contrary to Holt’s and Parfit’s conclusion, I would contend that it doesn’t fit
the evidence. Our universe is far from mediocre if it’s produced life and
consciousness. The ‘selector’, it should be pointed out, could be a condition
like ‘goodness’ or ‘fullness’. But, after reading their discussion, I concluded
that the logical ‘selector’ is the anthropic principle, because that’s what
we’ve got: a universe that’s comprehensible containing conscious entities that
comprehend it.
P.S. I wrote a post on The Anthropic Principle last month.
P.S. I wrote a post on The Anthropic Principle last month.
Addendum 1: In reference to the anthropic principle, the abovementioned post
specifies a ‘weak’ version and a ‘strong’ version, but it’s perhaps best
understood as a ‘passive’ version and an ‘active’ version. To combine both
posts, I would argue that the fundamental ontological question in my title,
raises an obvious, fundamental ontological fact that I expound upon in the
second last paragraph: ‘without consciousness, there might as well be nothing.’
This leads me to be an advocate for the ‘strong’ version of the anthropic
principle. I’m not saying that something can’t exist without consciousness, as
it obviously can and has, but, without consciousness, it’s irrelevant.
Addendum 2 (18 Nov.
2012): Four months ago I wrote a comment in response to someone recommending Robert
Amneus's book, The Origin of the Universe; Case Closed (only available as
an e-book, apparently).
In particular, Amneus
is correct in asserting that if you have an infinitely large universe with
infinite time, then anything that could happen will happen an infinite number of times, which explains how
the most improbable events can become, not only possible, but actual. So mathematically, given enough space and time, anything that can
happen will happen. I would contend that this is as good an answer to the
question in my heading as you are likely to get.
Wednesday, 18 July 2012
The real war in Afghanistan is set in hell for young girls
This is probably the most disturbing documentary I’ve seen on television, yet it elevates 4 Corners to the best current-affairs programme in Australia and, possibly, the world. I remember reading in USA
Today, when American and coalition forces first went into Afghanistan after
9/11 (yes, I was in America at the time) a naïve journalist actually worrying
that the change to democracy in Afghanistan might occur too quickly. I found it
extraordinary that a journalist covering international affairs had such a
limited view of the world outside their own country.
My understanding of Afghanistan is limited
and obviously filtered through the eyes, ears and words of journalists, but
there appears to be two worlds: one trying to break into the 21st
Century through youthful television programmes (amongst other means) and one
dominated by tribal affiliations and centuries-old customs and laws. In the
latter, it is the custom to settle disputes by the perpetrator’s family giving
land or daughters to the victim’s family. In other words, daughters are treated
as currency and as bargaining chips in negotiations. In recent times, this has
had tragic consequences resulting from a NATO-backed policy to destroy opium crops,
which is the only real way that Afghan farmers can make money. Opium is the
source of income for the Taliban but the trade is run by drug smugglers, based
in Pakistan. They are the Afghani equivalent of the mafia in that they are
merciless. With the destruction of crops, that the drug smugglers finance, they
are abducting the farmer’s daughters, from as young as 7 years (as evident in
the 4 Corners programme) for payment
of their debts. The government and NATO are simply ignoring the problem, and as
far as the Taliban is concerned, it’s an issue between the drug smugglers and
the farmers.
This is a world that most of us cannot
construe. If you put yourself in their shoes and ask: What would I do? Unless
you are delusional, the answer has to be that you would do the same as them:
you’d have no choice. It’s hard for us to imagine that there exists a world
where life is so cheap, yet poverty, perpetual conflict and no control over
one’s destiny inevitably leads to such a world. I hope this programme opens
people’s eyes and breaks through the cocoon skin that most of us inhabit.
More than anything else, it demonstrates
the moral bankruptcy of the Taliban, the cultural ignorance of the coalition
and the inadequacy of Pakistani law enforcement.
Wednesday, 11 July 2012
It’s time the Catholic Church came out of the Closet
This programme was aired a couple of weeks
ago on ABC’s 4 Corners, but it demonstrates how out-of-touch the Catholic
Church is, not only with reality, but with community expectations. More than
anything else, the Church lets down its own followers, betrays them in fact.
This deals specifically with a couple of
cases in Australia, and it’s amazing that it takes investigative journalism to
shine a light on them. Most damning for the Church, is evidence that protecting
their pedophilic clergy and their own reputation was more important than
protecting members of their congregation.
The most significant problem, highlighted
by the programme, is the implicit belief, held by the Church and evidenced by
their actions, that they are literally above the law that applies to everyone
else.
This is an institution that claims to have
the high moral ground on issues like abortion, therapeutic cloning, gay
marriage, euthanasia, to nominate the most controversial ones, when it so
clearly lacks any moral credibility. Most people in the West simply ignore the
Catholic Church’s more inane teachings regarding contraception, but in
developing countries, the Church has real clout. In countries where protection
against AIDS and birth control are important issues, both for health and
economic reasons, the Church’s attitude is morally irresponsible. The Catholic
Church tries to pretend that it should be respected and taken seriously, and
perhaps one day it will, when it enters the 21st Century and
actually commits to the same laws as the people it supposedly preaches to.
Saturday, 30 June 2012
The Anthropic Principle
I’ve been procrastinating over this topic
for some time, probably a whole year, such is the epistemological depth hidden
behind its title; plus it has religious as well as scientific overtones. So I
recently re-read John D. Barrow’s The
Constants of Nature with this specific topic in mind. I’ve only read 3 of
Barrow’s books, though his bibliography is extensive, and the anthropic
principle is never far from the surface of his writing.
To put it into context, Barrow co-wrote a
book titled, The Anthropic Cosmological
Principle, with Frank J. Tipler in 1986, that covers the subject in
enormous depth, both technically and historically. But it’s a dense read and The Constants of Nature, written in
2002, is not only more accessible but possibly more germane because it
delineates the role of constants, dimensions and time in making the universe
ultimately livable. I discussed Barrow’s The
Book of Universes in May 2011, which, amongst other things, explains why
the universe has to be so large and so old if life is to exist at all. In March
this year, I also discussed the role of ‘chaos’ in the evolution of the
universe and life, which leads me (at least) to contend that the universe is
purpose-built for life to emerge (but I’m getting ahead of myself).
We have the unique ability (amongst species
on this planet) to not only contemplate the origins of our existence, but to
ruminate on the origins of the universe itself. Therefore it’s both humbling,
and more than a little disconcerting, to learn that the universe is possibly
even more unique than we are. This, in effect, is the subject of Barrow’s book.
Towards the end of the 19th
Century, an Irish physicist, George Johnstone, attempted to come up with a set
of ‘units’ based on known physical constants like c (the speed of light), e
(the charge on an electron) and G (Newton’s gravitational constant). At the
start of the 20th Century, Max Planck did the same, adding h
(Planck’s quantum constant) to the mix. The problem was that these constants
either produced very large numbers or very small ones, but they pointed the way
to understanding the universe in terms of ‘Nature’s constants’.
Around the same time, Einstein developed
his theory of relativity, which was effectively an extension of the Copernican
principle that no observer has a special frame of reference compared to anyone
else. Specifically, the constant, c, is constant irrespective of an observer’s
position or velocity. In correspondence with Ilse Rosenthal-Schneider
(1891-1990), Einstein expressed a wish that there would be dimensionless
constants that arose from theory. In other words, Einstein wanted to believe
that nature’s constants were not only absolute but absolutely no other value. In his own words, he wanted to know if “God had any
choice in making the world”. In some respects this sums up Barrow’s book,
because nature’s constants do, to a great extent, determine whether the
universe could be life-producing.
On page 167 of the paperback edition
(Vintage Books), Barrow produces a graph that shows the narrow region allowed by
the electromagnetic coupling constant, α, and the mass ratio of an electron to a proton,
β, for a habitable universe with
stars and self-reproducible molecules. Not surprisingly, our universe is
effectively in the middle of the region. On page 168, he produces another graph
of α
against the strong coupling constant, αs,
that allows the carbon atom to be stable. In this case, the region is extraordinarily
small (in both graphs, the scales are logarithmic).
I was surprised to learn that Immanuel Kant was
possibly the first to appreciate the relationship between Newton’s theory of
gravity being an inverse square law and the 3 dimensions of space. He concluded
that the universe was 3D because of the inverse square law, whereas, in fact,
we would conclude the converse. Paul Ehrenfest (1890 – 1933), who was a friend
of Einstein, extended Kant’s insight when he theorised that stable planetary
orbits were only possible in 3 dimensions (refer my post, This is so COOL, May
2012). But Ehrenfest made another revelation when he realised that 3
dimensional waves were special. In even dimensions, different parts of a ‘wavy
disturbance’ travel at different speeds, and, whilst waves in odd dimensions
have disturbances all travelling at the same speed, they become increasingly
distorted in dimensions other than 3. On page 222, Barrow produces another
graph demonstrating that only a universe with 3 dimensions of space and one of
time, can produce a universe that is neither unpredictable, unstable nor too
simple.
But the most intriguing and informative chapter
in his book concerns research performed by himself, John Webb, Mike Murphy,
Victor Flambaum, Vladimir Dzuba, Chris Churchill, Michael Drinkwater, Jason Prochaska
and Art Wolfe that the fine structure constant (α) may have been a different value in the far distant past by the
miniscule amount of 0.5 x 10-5, which equates to 5 x 10-16
per year. Barrow speculates that there are fundamentally 3 ages to the universe,
which he calls the radiation age, the cold dark matter age and the vacuum
energy age or curvature age (being negative curvature) and we are at the start
of the third age. He simplifies this as the radiation era, the dust era and the
curvature era. He contends that the fine structure constant increased in the
dust era but is constant in the curvature era. Likewise, he believes that the
gravitational constant, G, has decreased in the dust era but remains constant
in the curvature era. He contends: ‘The vacuum energy and the curvature are the
brake-pads of the Universe that turn off variations in the constants of
Nature.’
Towards the end of the book, he contemplates the
idea of the multiverse, and unlike other discussions on the topic, points out
how many variations one can have. Do you just have different constants or do
you have different dimensions, of both space and/or time? If you have every
possible universe then you can have an infinite number, which means that there
are an infinite number of every universe, including ours. He made this point in
The Book of Universes as well.
I’ve barely scratched the surface of Barrow’s
book, which, over 300 pages, provides ample discussion on all of the above
topics plus more. But I can’t leave the subject without providing a definition
of both the weak anthropic principle and the strong anthropic principle as
given by Brandon Carter.
The weak principle: ‘that what we can expect to observe must be restricted by the condition
necessary for our presence as observers.’
The strong principle: ‘that the universe (and hence the fundamental parameters on which it
depends) must be such as to admit the creation of observers with it at some
stage.’
The weak principle is effectively a
tautology: only a universe that could produce observers could actually be observed.
The strong principle is a stronger contention and is an existential one. Note
that the ‘observers’ need not be human, and, given the sheer expanse of the
universe, it is plausible that other ‘intelligent’ life-forms could exist that
could also comprehend the universe. Having said that, Tipler and Barrow, in The Anthropic Cosmological Principle,
contended that the consensus amongst evolutionary biologists was that the
evolution of human-like intelligent beings elsewhere in the universe was
unlikely.
Whilst this was written in 1986, Nick Lane
(first Provost Venture Research Fellow at University College London) has done
research on the origin of life, (funded by Leverhulme Trust) and reported in New Scientist (23 June 2012, pp.33-37)
that complex life was a ‘once in four billion years of evolution… freak
accident’. Lane provides a
compelling argument, based on evidence and the energy requirements for cellular
life, that simple life is plausibly widespread in the universe but complex life
(requiring mitochondria) ‘…seems to hinge on a single fluke event – the
acquisition of one simple cell by another.’ As he points out: ‘All the complex
life on Earth – animals, plants, fungi and so on – are eukaryotes, and they all
evolved from the same ancestor.’
I’ve said before that the greatest mystery
of the universe is that it created the means to understand itself. We just
happen to be the means, and, yes, that makes us special, whether we like it or
not. Another species could have evolved to the same degree and may do over many
more billions of years and may have elsewhere in the universe, though Nick
Lane’s research suggests that this is less likely than is widely believed.
The universe, and life on Earth, could have
evolved differently as chaos theory tells us, so some other forms of
intelligence could have evolved, and possibly have that we are unaware of. The Universe
has provided a window for life, consciousness and intelligence to evolve, and
we are the evidence. Everything else is speculation.
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