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The Quantum Revolution We are in the middle of a major paradigm shift, one
that began early in the twentieth century and is still unfolding. Where it
will end is not fully revealed, but it is clear that
we will need to see reality with different eyes. Among other things, it
points to a merging of scientific understanding and spiritual experience. The notion of a paradigm was
introduced by the philosopher of science Thomas Kuhn in his seminal work, The
Structure of Scientific Revolutions. A paradigm is a whole set of
understandings within which we interpret the information which we encounter.
Although we think that we see things simply and
directly, we are constantly passing everything through our paradigmatic lens.
The medieval scholastic philosophers, for example, insisted that the sense
organs are infallible, that, as we say today, “seeing is believing.”
Not so. We see with our brain more than with our
eyes, and what our brain makes of our sense impressions depends on the paradigm
we are working within. Kuhn talks about the incredible paradigm shift from a
geocentric to a heliocentric solar system. Galileo’s evidence would have
stood up in any court of law. Telescopic images, the moons of Jupiter,
craters on the moon, the phases of Venus, and much more, built a case which could not be denied. And yet,
he was made to recant, not only by the Church but also by the academic
establishment, both of which had vested interests in retaining the status
quo. The middle of the nineteenth century saw another major
paradigm shift, one not yet completely digested, from a static view of the
universe to a dynamic one. Evolution of species, the descent of human beings,
the geologic formation of Earth as we know it, the origin of the universe in
a “big bang,” all seemed contrary to common sense, hard to believe. Of
course, there were major repercussions, not the least being the thought of Teilhard de Chardin, a
formulation of theology for the evolutionary paradigm. Heading into the beginning of the
twentieth century, it was felt that physics was essentially
complete, that the theoretical understanding of physical phenomena needed
only a little polishing. Newton’s formulation of mechanics explained
everything from the orbit of the moon to the trajectory of a cannonball,
extending even to the forces of stress on an architectural structure. The
philosopher LaPlace even suggested that if only we
knew the position and momentum of all particles in the universe, we could in principle calculate the course of all future
events. It was a highly deterministic paradigm, complete with a “watchmaker”
God who set everything in motion in the beginning and then turned away to
leave the laws of physics in charge. In the late nineteenth century, James Clerk-Maxwell formulated
some simple equations which describe the behavior of
electromagnetic radiation, bringing together the areas of optics, magnetism,
electricity, and the like, formerly thought to be separate phenomena. So there was a great sense of complacency
in physics, a feeling that between Newton and Clerk-Maxwell, everything
important was already understood. It is said that
students aspiring to careers in physics were being discouraged and pointed in
what were felt to be more promising fields. Within thirty years three
completely unanticipated developments shook the structure of physics to its
core: the discovery of radioactivity, the emergence of quantum mechanics, and
the formulation of special and general relativity. This essay will focus on
quantum mechanics. It began with a puzzling discrepancy between measured
data and the prediction based on the then current understanding of light as
it is emitted from a glowing object such as the sun.
The empirical data showed a peak on a curve of light intensity against frequency,
the position of the peak depending on the temperature of the emitter. The
predicted behavior showed a steady increase in intensity with no peak, the
curve going off toward infinity at the highest frequencies, the ultra-violet.
It was a most troubling result. At the time it was
referred to as the “ultraviolet catastrophe.” Max Planck in Germany offered a solution
which was able to reproduce the empirical result, but it required
considering the light as consisting of particles rather than waves. These
hypothetical, individual particles were called “quanta.”
But what could this possibly mean? Common sense
requires light to be wave-like, not particle-like. Further experiments showed
that whether light manifested as particle or as wave depended on the kind of experiment which is done. So it
appears that the nature of reality, at least in these experiments, depends on
the tool used to examine it. How startling! The theory for which Einstein received the Nobel Prize,
the photoelectric effect (his relativity papers were considered too
implausible by the selection committee consisting of previous Nobel
laureates, a group which might be expected to support the status quo), showed
that even electrons, so clearly particulate in nature, could show wave-like
properties under appropriate experimental conditions. Even
more startling! An explanation, if something so
contradictory to common sense may be called so, was offered by Werner
Heisenberg, the “Uncertainty Principle,” which states that it is impossible
to determine precisely both the position and the velocity of any particle at
the same time. Under conditions which seek to determine
position, it appears as a particle, although we cannot know its velocity.
Under conditions which seek to determine its energy (which
is related to velocity) it appears as a wave, which cannot be said to
have a position. Now, this sounds like epistemology, a statement about
limitations on what it is possible to know, rather than about reality. In
fact, that facile way of escape is closed off. Much
empirical evidence, including practical devices depending on the phenomenon,
show conclusively that it is not simply about what we can know, but rather
about what really is. It has also been said that,
after all, these strange concepts apply to the microscopic world of electrons
and not to the world of human beings. But quantum
mechanics has been shown to apply to the cosmos, particularly in relation to
its emergence from the big bang, so it cannot be limited to microscopic
particles. All of this sounds so strange because we are still
living in an outmoded paradigm. Our new paradigm may very well see the
merging of reductionistic science with spiritual
experience. We may find that consciousness is widespread throughout the
universe (as Teilhard taught), that we may discover
a deep unity behind all the particles, people, planets, pebbles, etc. We may
find that, as quantum physics pioneer Erwin Schrödinger said, “The total
number of minds in the universe is one.” As a part of that universal unity,
how can we do violence to one another? Dom
Roberti |