Feynman's Cosmic
Onion
Albert Einstein
believed that the universe was created by a rational god; a god who
would never presume to play dice with his precious creation.
Einstein's belief in a rational, knowable universe was rooted in a
“clockwork” scientific philosophy that comprised the very bedrock
of Enlightenment science. This perspective was most famously summed
up by Pierre-Simon Laplace (1749-1827):
An intelligence knowing all the
forces acting in nature at a given instant, as well as the momentary
positions of all things in the universe, would be able to comprehend
in one single formula the motions of the largest bodies as well as of
the lightest atoms in the world, provided that its intellect were
sufficiently powerful to subject all data to analysis; to it nothing
would be uncertain, the future as well as the past would be present
to its eyes (Quoted in Weinert, 2004, p. 197).
Laplace was
convinced that, so long as he and his intellectual heirs remained
committed to the cause of rational scientific inquiry, their
endeavors would ultimately yield a complete and thorough knowledge of
the universe. All that had been hidden, would inexorably become
“present to the eyes” of rational science. Yet, if scientists
have learned anything over the past century it is that the universe
is anything but rational: the chief claim of quantum mechanics,
perhaps the most extraordinary set of insights ever revealed by
modern science, is that it is impossible to know everything about
anything. Though Einstein refused to accept this unsettling
truth, quantum physicists have demonstrated time and time again that
it is impossible to specify the exact properties of even a single
quantum particle.
Still, in spite of
the epistemological limitations of quantum reality, some scientists
still cling to the notion that the universe is knowable and
deterministic in a Laplacian sense:
Given the state of the universe
at one time, a complete set of laws fully determines both the future
and the past...The scientific determinism that Laplace formulated
is...the basis of all modern science, and a principle that is
important throughout this book...Since people live in the universe
and interact with other objects in it, scientific determinism must
hold for people as well.
Though we feel we can choose
what we do, our understanding of the molecular basis of biology shows
that biological processes are governed by the laws of physics and
chemistry and therefore are as determined as the orbits of the
planets (Hawking and Mlodinow, 2010, pp. 30-32).
Influential as
Hawking may be, there are other equally eminent scientists who take a
very different view of the implications of quantum mechanics:
In classical physics it would
have been legitimate to specify exactly both the position and the
momentum of a given particle at the same time, but in quantum
mechanics that is forbidden, as is well known, by the uncertainty, or
indeterminacy, principle. The position of a particle can be specified
exactly, but its momentum will then be completely undetermined
(Gell-Mann, 1994, p. 139, emphasis added).
Another most interesting change
in the ideas and philosophy of science brought about by quantum
physics is this: it is not possible to predict exactly what
will happen in any circumstance...nature, as we understand it today,
behaves in such a way that it is fundamentally impossible
to make a precise prediction of exactly what will happen
in a given experiment (Feynman, et al., 1963, p. 35, emphasis in
original)
So where does this
leave us? As scientists have expanded the frontiers of knowledge,
they have gradually come to realize that the universe is chock full
of mysteries that may forever elude even the cleverest and most
persistent of truth-seekers:
People say to me, “Are you
looking for the ultimate laws of physics?” No, I’m not, I’m
just looking to find out more about the world and if it turns out
there is a simple ultimate law which explains everything, so be it.
That would be very nice to discover.
If it turns out it’s like an
onion with millions of layers and we’re just sick and tired of
looking at the layers, then that’s the way it is, but whatever way
it comes out it’s nature is there and she is going to come out the
way she is, and therefore when we go to investigate it we shouldn’t
predecide what it is we’re trying to do except to try to find out
more about it (Feynman and Robbins, 1999, p. 23).
Thus, science is
nothing if not an intellectual adventure. Will we ever arrive at the
final, absolute Laplacian truth? I hope not. Throughout history, the
most dangerous and ignorant people have always been those who were
convinced that they knew everything. In contrast, real geniuses are
never the folks who think they have all the answers. Instead, true
geniuses are the people who, by hook or crook, figure out how to ask
the right questions.
Sure, there are
truths to be revealed. The real beauty of science is that, every time
we think we might be getting close to knowing everything, a few
nagging “dark” matters succeed in emphasizing how little we truly
know.
If it is impossible
to know everything about about any individual quantum particle, will
humans ever know everything about everything? I won't even bother to
answer such a self-evident and pointless question question. By
searching for the ultimate answer to everything, science does nothing
but shoot itself in the foot.
One of the ways of stopping
science would be only to do experiments in the region where you know
the law. But experimenters search most diligently, and with the
greatest effort, in exactly those places where it seems most likely
that we can prove our theories wrong. In other words, we are trying
to prove ourselves wrong as quickly as possible, because only in that
way can we find progress (Feynman, 1965, p. 151).
Scientists do their
best work when the humbly own up to to their own ignorance. In spite
of Laplace's insistence to the contrary, no human either can or ever
will know everything. Further, any scientist with an ounce of sense
would never claim otherwise. Science is an enterprise that succeeds
in revealing new truths by taking one plodding step forward—or, as
Feynman suggests, by peeling back one layer of a cosmic onion—at a
time.
Finally, a word to
the wise: if there is a god, he does play dice with the
universe. Scientists who don't wish to crap out would be well advised
to wise up to the rules of his game.
References
Feynman, R. P., R. B. Leighton, and M. Sands. The Feynman Lectures on Physics: Quantum Mechanics: Volume III. Reading: n.p., 1963.
Feynman, Richard P. The Character of Physical Law. Cambridge: M.I.T., 1965.
Feynman, Richard P., and Jeffrey Robbins. The Pleasure of Finding Things Out: The Best Short Works of Richard P. Feynman. Cambridge, MA: Perseus, 1999.
Gell-Mann, Murray. The Quark and the Jaguar: Adventures in the Simple and the Complex. New York: W.H. Freeman, 1994.
Hawking, Stephen, and Leonard Mlodinow. The Grand Design. New York: Bantam Books, 2010.
Weinert, Friedel. The Scientist as Philosopher: Philosophical Consequences of Great Scientific Discoveries. Berlin: Springer, 2004.