"
When we try to pick out anything by itself, we find it hitched to everything else in the universe." -- John Muir
When Descartes partitioned the world into the
res extensa (material objects) and the
res cogitans (mind), he treated the two domains quite differently. In chapter VI of
Meditations and Principles (1644), he writes:
"... there is a vast difference between the mind and body,
in respect that body, from its nature, is always divisible, and that
mind is entirely indivisible."
The body he viewed as a machine, which could be understood by the
interactions of its constituent parts. Hence, the dissection of material
objects, in general, into their components -- that is,
reductionism -- was seen as a viable approach to understanding the whole.
Many quarters of science have benefited from reductionist
investigations.
Modern medicine owes much of its efficacy to
understanding the functions of the various organs -- the heart, lungs,
kidneys, and so on -- and to their contributions to the physiology of
the whole. Likewise the
standard model of particle physics has
resulted from physics' relentless persistence in probing the structure
of matter, all the way down to its tiniest ingredients -- protons,
electrons, and neutrons -- as well as the quarks that comprise these
basic constituents and the forces that glue them together. Gilding the
lily of the standard model was the recent discovery of the long-elusive
Higgs boson, colorfully (but misleadingly) dubbed the "God particle."
Biology too has made great leaps through reductionism. By laser-like
focus on the genetic molecule, science unraveled the structure of DNA in
1953, paving the way for the decoding of complete genomes a
half-century later. In particular, the massive
Human Genome Project
(HGP), which completed the sequencing of human DNA in 2003, promises
designer cures for all manner of diseases via drugs tailor-made for the
individual according to his or her genetic makeup.
Reductionism, however, has its limitations. Many mainstream psychologists rue the day when the reductionist
behaviorism
of J. B. Watson and B. F. Skinner hijacked the discipline of
psychology, setting the field back, some estimate, by 50 years. Is a
human being--one who bristles at injustice, weeps at Pachelbel's Canon,
loves her children, is awestruck by beauty, and craves chocolate --
simply the product of Pavlov's conditioned reflexes to stimuli? I can't
help but think fondly of my mother-in-law, who passed away to kidney
failure at just 68 years of age following a series of strokes. While
Harriett grappled with the prospect of either a lifetime of dialysis or
of letting go, a parade of medical specialists came and went, each
treating a different organ, and each leaving Harriett more bereft. It
was the rehab specialist, an MD trained originally as a nurse and adept
at ministering to the whole person, who meant the most to Harriet in her
final days.
Reductionist models can be valuable, but at best they crudely approximate reality. In 2011, two colleagues and I published (
Computer Physics Communications, Vol. 182) a novel procedure for solving the classic
n-body problem, which asks: What are the trajectories of
n
mutually gravitating bodies? For grins, we applied the new algorithm to
evolve our solar system three million years into the future. The
nagging uncertainty among astronomers regarding the long-term stability
of our planetary system motivated the test case. Could gravitational
forces gang up years hence to eject a planet and collapse the system?
Happily, our simulation corroborated the results of others: a stable
status quo persists for at least another few million years.
Now the disclaimer. We considered a system comprised of just 10
bodies, the sun and 9 planets (including Pluto). All moons were excluded
from the calculation, as were asteroids, relativistic effects, and the
weak gravitational influences of distant galaxies. You have to draw a
line somewhere, and we drew it at
n=10. With more effort, we could have drawn the line at
n=1000, or with a lot more effort at
n=1,000,000 or more. The point is: short of
n
being the number of bodies in the universe, the model is incomplete,
and one or more of those disregarded bodies could ultimately upset the
apple cart, that is, the stability of the solar system.
Consider also the
second law of thermodynamics, which states that
entropy (disorder) cannot decrease in an
isolated system
(one that can exchange neither energy nor matter with its
surroundings). Thus, a type of reductionism occupies the very heart of
thermodynamics by allowing us, in principle, to wall off a system from
its environment. But truly isolated systems are hard to find.
Mercifully, the earth is not isolated because of the great flux of
radiant energy we receive from the sun (as well as the occasional meteor
that adds to the earth's mass, such as the one that recently rocked
Chelyabinsk, Russia). In truth, isolated systems are nonexistent
idealizations; no real system can be hermetically sealed from all
outside influences. Perhaps the only truly isolated system is the entire
cosmos, for as Muir observed (above), everything is "hitched to
everything else."
For some, the sequencing of the human genome in 2003 -- spectacular
as it was -- evoked a sense of letdown. For all their efforts, what had
researchers gleaned about being human? Not much initially (except that
humans have far fewer genes than anticipated). Some found the
accomplishment hollow, likening it to the completion of a phone
directory for New York City. Having all those names and addresses
reveals nothing about the interactions of the persons listed.
Perhaps the HGP's great accomplishment, however, lay in exposing the importance of biology's newest frontier:
epigenetics, the science of gene
expression.
It's not enough to know the genome. Genes encode heritable traits, but
only if those genes are activated, or "expressed." Although identical
twins begin life with identical genomes, by old age their genetic makeup
may differ by 50 percent or more. All manner of environment factors --
lifestyle, diet, habits, exercise -- affect gene expression.
Epigenetics has revived the old nature-nurture debate. What we become
depends literally upon all that happens to us over a lifetime. Genes
alone do not make an individual; it takes an ecosystem.
In 1991, Michael Talbot published
The Holographic Universe. Based upon the insights into
quantum entanglement by University of London physicist David Bohm and the neurophysiology of Stanford University's Karl Pribram,
The Holographic Universe
presents a paradigm-shifting view of the nature of reality by which the
whole is contained in every part. The book's title comes from the
remarkable properties of
holograms, three-dimensional images
constructed by laser interference and stored on two-dimensional film.
Unlike conventional photographic negatives, however, each tiny piece of
holographic film encodes the entire three-dimensional image!
Holography is a fitting metaphor for what mystics have always taught:
separation is illusion. The universe is a seamless whole. Reductionism
has revealed much, but its utility may have run its course. I anticipate
that holism has as great a role to play in the future of science as
reductionism has played in its past.
The final two posts in this series will address science's most stubborn assumption:
materialism.
No comments:
Post a Comment