[I think I'm going to focus on metaphysics this month. Not exclusively, but I feel my blog on Solipsism vs. Occum's Razor some months back left some business unfinished.]
There are
several questions and problems in Philosophy that are considered particularly
difficult or troubling. What is Art, the Sorites Paradox, The Problem of
Substance, and The Problem of Consciousness are among them. Although science is
closing in on The Problem of Consciousness, there’s a big “maybe” hanging over
its head because the biggest question of all is the mother of all the other
problems. It is a question every philosopher should be concerned with if any
other question or problem is to be resolved – what is reality?
I recently
stumbled across an old article (which you can read below) in which the author
makes note of how indeterminacy in the quantum world affects what takes place
at the macro level of events. More precisely, due to the way in which the
quantum world behaves, the very act of observing the (supposed) world of
extended objects shapes what appears to be reality for a subject, and this
casts doubt on a reality in which things and events are the same for all
observers. While Einstein also noted that observations are not in fact the same
for all subjects, this was due to a subject’s location in time and space,
dimensions through which information must travel and thus, an event may be
observed differently in one location and time than another (to say nothing of
the inferences one makes of such observations). While many philosophical
conundrums have ended in science, this time scientific findings have raised
more questions than answers. What happens when something like a particle of
light or an electron is observed raises doubt about reality to a whole new
level.
The dual
nature of light, for example, has been known for some time yet no one –
philosopher or scientists – seems to trying very hard to understand what such properties
of quantum bits (information) means.
(I find this very strange for a species that casts themselves upon a pedestal
due to their ability to think in terms of ‘meaning’ whereas other animals
supposedly cannot.) What does it mean
for light to act as a wave when it is not observed and as a particle when it is
observed?
Such a
question begets another question; does it mean reality only exists when there
is an observer present to collapse the quantum possibilities into a single
event? How does the act of observing collapse quantum possibilities into a
single event? Physicist Sir Roger Penrose believes gravity is responsible.
That’s a tantalizing answer to the question since his answer would allow
reality that is not observer-dependent to exist; there just needs to be objects
large enough present to exert the effects of gravity over quantum
possibilities. But that still leaves us with the question of whether reality
exists at the quantum level of events where the very phrase “quantum level of
events” becomes a misnomer. And, if we were to think back to the moments
following the Big Bang (assuming that is in fact how our universe began), how
did a quantum indeterminate world give rise to the force [gravity] necessary to
collapse its possibilities into real objects and their events? When I first
read it, I wanted to like Penrose’s answer but it, too, raises too many
questions.
I was once a
hard determinist who believed that the indeterminacies of the quantum world
appeared to be indeterminate because of variables we were unable to measure.
But if the experiments in the article really do confirm how bizarrely quantum
mechanics works, there is no uniform reality, a reality that uniform for all
observers. That makes for a possibly disturbing consequence: That one person’s
interpretation or observation of reality is as much ‘real’ as the next person’s
reality. Such a consequence leads us to another question; if I, as a sole
observer, am the only observer that I can even begin to suspect actually exists,
is reality mine alone? And, how could reality have created itself until an
observer existed; that is, what came first, the possibility of reality or the
observer? Did each come into existence simultaneously? Granted, these questions
are speculative but I do not regard them to be completely so since as a
philosopher am trying to understand what – if anything – scientific findings
mean. My speculative questions are, to me, the natural result of what science
has unveiled.
Though once
a hard determinist, I’m not sure what my current metaphysical view could be
categorized as. While I understand how reality is observer dependent, if I
believe that and believe that other
agents, other observers besides myself exist, there is no single unified
reality. This would certainly shore up some of my previous assertions, such as
how easily Plato’s Law of Non-Contradiction is broken or that God can both
exist and not exist at the same time. But I can’t want to believe those
assertions just because I want to. Such assertions should make sense, shouldn’t
they? Only, if reality is mine to observe and construe, of course it’s going to
make sense.
Quantum Physics Says Goodbye to Reality
Apr 20, 2007 by Jon Cartwright (for Physics Web)
Some physicists are uncomfortable
with the idea that all individual quantum events are innately random. This is
why many have proposed more complete theories, which suggest that events are at
least partially governed by extra "hidden variables". Now physicists
from Austria claim to have performed an experiment that rules out a broad class
of hidden-variables theories that focus on realism -- giving the uneasy
consequence that reality does not exist when we are not observing it (Nature
446 871).
Some 40 years ago the physicist John
Bell predicted that many hidden-variables theories would be ruled out if a
certain experimental inequality were violated – known as "Bell's
inequality". In his thought experiment, a source fires entangled pairs of
linearly-polarized photons in opposite directions towards two polarizers, which
can be changed in orientation. Quantum mechanics says that there should be a
high correlation between results at the polarizers because the photons
instantaneously "decide" together which polarization to assume at the
moment of measurement, even though they are separated in space. Hidden
variables, however, says that such instantaneous decisions are not necessary,
because the same strong correlation could be achieved if the photons were
somehow informed of the orientation of the polarizers beforehand.
Bell's trick, therefore, was to
decide how to orient the polarizers only after the photons have left the
source. If hidden variables did exist, they would be unable to know the
orientation, and so the results would only be correlated half of the time. On
the other hand, if quantum mechanics was right, the results would be much more
correlated – in other words, Bell's inequality would be violated.
Many realizations of the thought
experiment have indeed verified the violation of Bell's inequality. These have
ruled out all hidden-variables theories based on joint assumptions of realism,
meaning that reality exists when we are not observing it; and locality, meaning
that separated events cannot influence one another instantaneously. But a violation
of Bell's inequality does not tell specifically which assumption – realism,
locality or both – is discordant with quantum mechanics.
Markus Aspelmeyer, Anton Zeilinger
and colleagues from the University of Vienna, however, have now shown that
realism is more of a problem than locality in the quantum world. They devised
an experiment that violates a different inequality proposed by physicist
Anthony Leggett in 2003 that relies only on realism, and relaxes the reliance
on locality. To do this, rather than taking measurements along just one plane
of polarization, the Austrian team took measurements in additional,
perpendicular planes to check for elliptical polarization.
They found that, just as in the
realizations of Bell's thought experiment, Leggett's inequality is violated –
thus stressing the quantum-mechanical assertion that reality does not exist
when we're not observing it. "Our study shows that 'just' giving up the
concept of locality would not be enough to obtain a more complete description
of quantum mechanics," Aspelmeyer told Physics Web. "You would
also have to give up certain intuitive features of realism."
However, Alain Aspect, a physicist
who performed the first Bell-type experiment in the 1980s, thinks the team's
philosophical conclusions are subjective. "There are other types of
non-local models that are not addressed by either Leggett's inequalities or the
experiment," he said. "But I rather share the view that such debates,
and accompanying experiments such as those by [the Austrian team], allow us to
look deeper into the mysteries of quantum mechanics.
