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THE
UNIVERSE IN THE LIGHT OF MODERN PHYSICS
“The
least understood aspect of the universe
is its being understandable,” said
Einstein. These words attempt to pierce
the veil of habit that develops in our
minds from not looking into the reason
for things. The perfection of the order
operative in the universe is of such a
degree that it prevents us from being
aware of it. In the same way, we only
become aware of the faultless operation
of the watches we’ve worn on our
wrists for years when they stop working.
In
the world-view developed upon the
foundation of Newton’s laws of motion,
the universe was likened to a flawlessly
operating watch. Events were tied to one
another in a cause-effect relationship
and our knowing the laws of this
relationship allowed us to predict
events with great accuracy. It was
possible to determine with mathematical
exactness a wide range of phenomena,
from the times of eclipses of sun and
moon to the amount of fuel and the speed
needed to put an object into orbit
around the earth. The success of these
‘natural laws’ led many people to
believe that they completely expressed
and ‘ruled’ the whole order of the
universe.
Because
God creates and sustains all things and
events from behind the veil of universal
general laws, because certain events
(causes) are followed reliably by
similar events (effects) each time they
(the causes) occur, it begins to be
supposed that the causes are responsible
for or ‘create’ the effects. This
is, of course, a gross error, as no
number of causes suffices to create even
a little effect; for every event, even
the tiniest, the whole universe must be
presupposed first, including the laws
operative within it. Moment by moment,
all things and all events are created
and sustained by God, Who wills from an
infinite range of alternative
possibilities a particular actuality.
The
clockwork model of the universe derived
from Newtonian or classical physics is
not a complete account of the phenomena
which we observe in the universe.
Already in the late 19th century,
scientists had been bewildered by the
lines that turned up in the light
spectra emitted by heated gases: the
steady, stable, even distribution the
clockwork model predicted did not
happen. Also, there were problems
explaining the behavior of light:
sometimes it made more sense as a beam
of particles, sometimes as a wave.
Today
our understanding of the universe is
very far from the ‘clockwork’ model.
The shift in understanding occurred in
the first quarter of the 20th century,
beginning in 1900 with the publication
of Max Planck’s work on radiation. The
problem Planck worked on for six years
was that the actually measured radiation
from hot bodies did not conform to the
values predicted by the classical
theory. He put forward the suggestion
that bodies radiating energy did so, not
evenly and continuously, but unevenly
and discontinuously in tiny packets or
‘quanta’. So startling was this
suggestion that, despite confirmation by
experiment, Planck himself thought of
his theory as solving the problem of
radiation by a sort of trick.
But
then, in 1905, Albert Einstein published
an article using the notion of packets
of energy of definite sizes to explain
how electrons are ejected from metal
when light (radiation) falls on it.
Whereas classical theory had predicted
that the voltage (measure of the energy
of the electrons ejected) would be
proportional to the intensity of the
light (radiation), Einstein showed that
it was proportional instead to the
frequency of the radiation. The
conformity of this explanation with
experimentally observed results gained
Einstein the Nobel Prize. (Einstein didn’t
receive the prize for his famous theory
of relativity.) The significance of
these findings and theories was not
fully appreciated at the time.
A
few years later in 1910, Ernest
Rutherford did a ground-breaking
experiment. He bombarded a thin layer
made up of gold atoms with high energy
particles and showed that the atom
contained an extremely small
positively-charged nucleus with
negatively-charged electrons moving
around it. Following the classical
physics model, these electrons should
have been small particles orbiting the
nucleus in the same way as the planets
orbit the sun, steadily losing energy
until they fell on to the nucleus ñ in
other words, the atom should have been
unstable. Again it was a rejection of
the classical model, three years later,
by Niels Bohr, that helped solve the
problem. Bohr argued that the electrons
must move in fixed orbits until
deflected by the absorption or emission
of a unit of energy.
Atoms
emit radiation after various external
signals and only at specific wave
lengths. As Einstein said, every
different color of light is composed of
energy packets inversely proportional to
its wavelength (frequency). Because the
Planck constant (h) is very small, the
energy of these packets is also very,
very small. For example, a normal light
bulb emits 1020 light packets (photons)
a second. Each of these photons is
created when an activated atom or
molecule passes to its normal or ‘basic
state.’ Thus light, which allows us to
see and which is a basic building block
of life, develops as a result of the
motions (in wave form) of electrons. The
concepts of classical physics could
successfully explain many of the events
of daily life, but it couldn’t explain
events on the subatomic level.
During
those years (1910-1925) physics fell
into a state of confusion because of the
many measurements that conflicted with
general theory and could not be
explained by it. This situation was to
lead W. Pauli (later to discover the
principle fundamental to the
understanding of the structure and
characteristics of elements) to say he
would rather have been a singer or
gambler than a physicist. Actually in
order to explain the observations being
made, the whole way in which physical
events had been understood required
fundamental revision by wholly new
methods. This was achieved by Werner
Heisenberg, a 24 year-old physicist
described by his teachers as a person
who dealt with the essence of a subject
rather than getting bogged down in
detail, a person with powerful
concentration and ambition. Perhaps the
success of this young mind can be
explained by the critical perspective he
developed through reading the works of
great men such as Kant and Plato, which
was later supported with sound knowledge
he got from great physicists. Heisenberg,
who relaxed from work by climbing rocks
and reading poetry, said: “It was
around three in the morning when the
calculations were completed and the
solution to the problem appeared in
front of me. First I experienced a great
shock. I was so excited I didn’t even
think about sleeping. I left the house
and, sitting on a rock, I waited for the
sunrise.”
Like
the other scientists who established
quantum physics, Heisenberg was a
philosopher-physicist. The philosophy he
accepted and advocated that allowed him
to interpret atomic events is as
follows: “Even though it is successful
with classical physics, the language we
use to explain physical events in the
atom or its surroundings is
insufficient. For this reason, after
making a specific measurement in a
quantum system (for example, an atom),
using that knowledge we can get a theory
that will tell us what kind of results
we can find in the next measurement. But
it’s not possible to say anything
about what takes place between the two
measurements.”
What
pushed Heisenberg to make such a
statement was that the mathematical
tools he used to develop a theory that
could explain the observed discontinuity
of energy in light and atoms were
abstract concepts that had not been used
before. In classical physics the numbers
we know were used to give value to
matter’s position, speed, size, etc.
In Heisenberg’s quantum mechanics,
these sizes were expressed with infinite
dimensional n x n matrices which enabled
physicists to calculate the properties
attributed to electrons (energy,
position, momentum, angular momentum) in
an approximate way. Because these
abstract mathematical expressions didn’t
have an equivalent in everyday spoken
language, it wasn’t possible to
approach them with a classical
understanding. It was observed that in
order to measure the position of an
electron, the experimenter necessarily
altered its velocity. This problem was
formally expressed in 1927 in Heisenberg’s
famous Uncertainty Principle.
Independently
of Heisenberg, Erwin Schrodinger made
another significant breakthrough in
mathematical description of electrons.
Inspired by the hypothesis put forward
two years earlier by De Broglie about
the wave properties of matter particles,
Schrodinger developed a ‘wave
mechanics’ by which the movement of
particles could be calculated. But the
fundamental question remained as to what
these strange and original ‘waves of
matter particles’ or ‘waves
accompanying matter particles’ were.
The
mathematical formulations devised by
Heisenberg and Schrodinger are
complementary in the sense that
physicists use whichever best resolves
the particular calculations they are
trying to make. There is no formally
distinct space between the scientists
and the phenomena they are seeking to
understand and manipulate: their means
of observation and manipulation (the
mathematics) in some sense ‘posit’,
put in place, the very phenomena whose
place (among other properties) they are
trying to determine. Alongside the
notion of an infinite array of rows and
points, as invented by Heisenberg, to
plot the position or motion of a
sub-atomic particle, physicists and
philosophers of physics have begun to
speak of arrays of events or ‘stories’
to try to explain, in something
resembling ordinary language, the ideas
they are handling. This cannot be
described as a world-view in the way
that the Newtonian physics confirmed and
sustained a world-view, but it is
nevertheless a clear and distinct
disposition which, instead of excluding
God as the Force Who wound up the
clockwork and then retired from His
creation, admits the incompleteness and
uncertainty of human knowledge as a
structural element of reality ñ in
other words, the uncertainty is not a
function of our present ignorance (to be
relieved by future knowledge), but an
actual constituent of the way reality
is.
Quantum
physics, at least figuratively and
metaphorically, has became a vehicle for
the interpretation of such concepts as
matter, beyond-matter, energy, existence
and non-existence in a way nearer to
Divine sources; and led to many
physicists settling accounts with their
conscience and turning towards God Who
is understood to be simultaneously
transcendent and immanent, there and
here.
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