Relativity theory and Quantum theory
only differ in their predictions from classical physics in
three specific circumstances. The first case of failure in
classical physics pertains to high velocities, which is efficiently
explained with the theory of special relativity. Classical
physics also fail on very large, cosmic scales, in which general
relativity offers a more precise rationalization. The last
state that does not conform to the beliefs of traditional
physics is in the case of microscopic, atomic scales, which
is more competently conceptualized with quantum theory. Although
a classically minded skeptic may not initially agree with
these "metaphysical" theories and consider the ideologies
of modern physics to be abstruse, persuasive evidence of their
practiced validity in modern technology, as well as maintaining
percipient attention of their cognitive faculties may prove
means for them to believe otherwise. Through a cogent examination
of the experimental basis and core concepts of modern physics,
that entail the predictions they deduce about our universe,
I attest it will be difficult for a skeptic to continue to
dispute the philosophies of modern physics. Of the three defined
circumstances I propose to explore some of the experimental
and explanatory fundamentals of both Special Relativity, and
Quantum Theory.
Special relativity offers an explanation
to the observable inconsistencies of classical physics regarding
matter traveling at high velocities. This theory, developed
by Albert Einstein, is composed of two fundamental postulates:
The Principle of Relativity, which states that 'the laws of
physics are the same in all inertial reference frames'; and
the Light Postulate, which states that 'the speed of light
is the same in all inertial reference frames'. The motivation
for the 'discovery' and development of special relativity
emerged from the paradoxal consequences Einstein concluded
from traditional physics. Maxwell's laws concerning the electromagnetic
field claim that electromagnetic currents propagate at a fixed
speed, which additionally is equable to the speed of light.
Maxwell also stated that visible light never stops or slows
down, and is always traveling at a definite speed. Einstein
theorized, what were to happen if we chase a light beam at
light speed? Classical physics entails that we would catch
up to the light waves and they would appear to no longer be
in motion, but Maxwell's equations also showed that light
is never stationary, so it appeared as though the equations
were different for moving objects with respect to stationary
ones. Then which statement is correct, or is the speed at
which light travels independent of frame of reference? This
was the foundation for Einstein's resolution to this perplexing
contradiction posed by the founders of classical physics.
On an experimental basis, the first
indirect confirmation of special relativity came through the
Michaelson-Morley project. The purpose of the Michaelson-Morley
project was not to confirm special relativity, for it had
not yet been developed. Its purpose was to measure the speed
of the Earth through the ether. These physicists theorized
that since waves appear to propagate through a medium, such
as sound waves through air, or water waves through water,
that electromagnetic waves traveled through this immaterial
substance called the ether. They assumed that light traveling
in the same direction as the Earth would take less time to
travel a given distance opposed to light traveling the same
distance, perpendicular to the direction of the Earth. If
this hypothesis was true, then the speed of the earth through
the ether could be measured by calculating the difference
in time it would take for light to travel in the different
directions. They set up what was called the Michaelson interfermeter,
this device measured a light path parallel to the motion of
the Earth, and a light path perpendicular to the motion. Unfortunately
for Michaelson and Morley, no difference was observed, and
three possible conclusions were formulated. Either: The Earth
is at rest in the ether, which was undisputedly wrong; the
ether is dragged along with the Earth, which was the conclusion
of Michaelson and Morley; or the assumption is incorrect.
Then, how can explain the experimental result that both the
parallel motion and perpendicular motion measured identical
amounts of time for travel? Physicists before Einstein had
hypothesized that a distortion of moving objects such as clocks
or rulers could explain the null results of Michaelson and
Morley, but they had no way to indicate why there would be
such a distortion. But suppose we require the Principle of
Relativity to hold for this experiment. Then the lack of difference
between the two light beams would be due to the fact that
the laws of physics are relative, and for an observer on the
earth, moving with the earth (appearing to himself as stationary),
an observable difference between the two beams would be impossible.
If we were able to detect our own motion in an inertial frame
of reference what would happen if we were traveling at or
close to light speed, would the speed of light appear to shrink
to zero? This concept of relative frames of reference pertaining
to the laws of physics was Einstein's fundamental motivation
for developing Special Relativity. He postulated that nothing
can ever truly be 'at rest' and would only seem at rest with
respect to something else. If this assumption were true, it
would also entail that the means we use to measure space and
time function in peculiar way that conceals the motion and
speed of the measuring device from being observed in a uniformly
moving reference frame. Einstein then began to apply his Principle
to explain the odd effects that the equivalence of different
observers at a constant velocity had on measuring devices,
and observed three strange occurrences, two of which are the
concepts of relativity of simultaneity, and time dilation.
Experimentally, if you were to give
an observer two explosives, and that observer were to set
them off simultaneously, and at the same time send another
observer whizzing by at a constant velocity, the two observers
would argue over the simultaneity of the explosions. The traveling
observer would claim that one event happened before the other,
while the 'stationary' observer holding the explosives (wearing
protective gear as not to blow his arms off) would claim the
events happened simultaneously. This is where the simultaneity
shift comes in. The concept of the relativity of simultaneity
states that events are only simultaneous relative to an inertial
reference frame. To uphold the light postulate, when spacetime
diagrams of multiple reference frames are drawn, the slope
between the x and x' axes, or the difference in motion between
the two reference frames, must be equivalent to the slope
between the t and t' axes. It is then observable that the
lines of simultaneity, which are lines parallel to the x-axis,
are different for the two separate reference frames, explaining
the shift of simultaneity for the arguing observers.
The claim of time dilation is that
constantly moving clocks tick slower with respect to a stationary
reference frame. For if a moving clock kept the same time
as a stationary one, the moving clock could judge speeds of
other inertial reference frames, violating the Principle of
Relativity. This time dilation supported by the Principle
of Relativity, requires Reciprocity, which is a reciprocal
condition in a relationship. This reciprocity can be illustrated
in a spacetime diagram where A and A' represent two clocks
moving at different velocities with respect to one another.
Incorporating and illustrating the shift of simultaneity in
a spacetime diagram it is observable that A will conclude
A' ticks slower and vice versa.
Now that we've looked into the spacetime
theories of Special Relativity compensating for the lack of
consistent information available in classical physics pertaining
to high velocities, I will continue our expedition of modern
physics with the ideologies of Quantum Theory that constitutes
the theory of matter on atomic scales. For the validity of
Quantum Theory, I pose a theoretical question for those who
find themselves prone to disbelief of its primary concepts.
If in return for abandoning conventional preconception based
on common sense that we hold about the composure and function
of matter, we are better able to utilize and benefit from
the elementary power contained in matter, why then, not release
our tenacious predispositions? It may seem as though Quantum
Theory is the 'black sheep' of classical physics, defying
and recomposing the statutes of Newtonian physics, but Quantum
Theory enables man to continue the progression of our modern
technology. Quantum Mechanics combines the previously separated
theories of the state of matter, namely the corpuscular ontology
and wave theory that has dominated the concept of the state
of matter for the past three centuries into what is now referred
to as the wave-particle duality of matter.
The wave-particle duality of matter
brings about strange consequences. It seems as though the
behavior of an object, behaving like a particle or like a
wave, depends on how we choose to perceive it. That is to
say that our observation of an object is what determines the
properties of that object, and before we observe the object
we cannot say whether the object is wave-like, particle-like,
or even exists at all. Another oddity of Quantum physics is
the indeterminacy of science that the wave-particle duality
seems to suggest about the state of matter, an essential inability
to predict precisely the future state of affairs of a system.
Both these consequences are very hard to grasp for skeptics
and prequantum physicists alike, as they are in violation
of both common sense and classical physics. Quantum Theory
formulates postulates that govern by probability, and not
property. But aside from the perplexing predictions and ideologies
of Quantum physics, their theories have been successfully
confirmed in the laboratories, such as Young's 'two-slit'
experiment, or the discovery of the photoelectric effect.
The first experiment observably
explained by Quantum Theory is the interference and reinforcement
phenomena of light. Interference of a wave is when a crest
of a single wave collides with a trough of another wave yielding
a neutral or zero level waves. Reinforcement occurs when two
crests or two troughs meet, rendering an even higher crest,
or lower trough. This experimental procedure denotes why,
in execution of experiments such as the 'two-slit' experiment,
'bands' of light and dark are observed. When a light source
is places behind a barrier with one slit and another barrier
containing two slits and then a observation screen, the results
are bands of light and dark according to the occurrences of
interference of reinforcement. It is reasons such as this
observable interference of light that suggest the inconsistencies
of the corpuscular theory of matter.
In the nature of an electron, it
was observed that electrons move in discrete levels. The photoelectric
effect is the condition in which when light is shone upon
certain metals, electrons are released from the metal. Under
experimentation by physicist Philipp Lenard, it was expectedly
observed that the higher the intensity of incoming light the
more electrons are released from the given metal. What was
astonishing about the experiment was that the kinetic energy
of individual escaping electrons did not increase when the
intensity of the incoming light was increased. For light of
a given frequency, the kinetic energy of released electrons
was independent of the intensity of the incoming light. Even
stranger was the observation that the kinetic energy of the
outgoing electrons did in fact increase, when the frequency
of the incoming light was increased.
The very same year that Einstein
published his paper on the theory of relativity, he also proposed
a new theory of light, which explained Lenard's photoelectric
experiment results. Einstein theorized that light was not
evenly distributed over a region of space, as one would expect
from a wave, but rather travels in individual 'lumps' of energy.
He describes what we now refer to as the Light Quantum Hypothesis,
which states that high frequency heat radiation behaves as
if it were divided into spatially localized 'lumps' of energy.
As increase in light intensity corresponds to a greater number
of quantums of light. Since each quantum may eject an electron,
a greater number of them would increase the amount of ejected
electrons. However, for a light of a fixed frequency, the
energy of each quantum would remain the same, and is not increased
by increasing the number of quantums. So when a single electron
is hit by a single quantum the energy gained will remain the
same, regardless of the intensity of light. Increasing the
frequency of the individual light quantums will however increase
the amount of energy each quantum contains. Therefore even
at a low intensity, if the frequency is high enough, the electron
that is ejected will gain more energy. So even if the intensity
of light, or amount of light quantums are released, electrons
will only be released if the frequency, or energy contained
in each light quantums, is high enough. This theory that Einstein
proposed suggested particle-like properties of light. So which
is correct? Or are they both correct? Seemingly, it is only
a matter of observation that in different experimentations,
the behavior of matter (including light) can be concluded
as both particle-like, as well as wave-like.
In the face of twentieth century
physics, many groundbreaking discoveries have been made concerning
the nature of spacetime and matter. The largest contribution
to the development of Relativity and Quantum theories is the
ingenious work of Albert Einstein, as well as other Nobel
Prize winning physicists such as Planck and Lenard and many
others. After infiltrating through the processes of experimentation
of Special Relativity and Quantum Theory I find it hard to
object to their affirmations. Through acceptance of these
posed theories, in spite of their contradictions to common
sense and prequantum physics, we are able to produce better
technology in our medicinal institutions, entertainment technologies,
as well as improve our conceptual understanding of the universe
we live in. There are many other confirmations and theoretical
propositions to Special Relativity and Quantum Theory additional
to the ones I have explored in the confines of this paper.
I greatly encourage the further exploration of the world of
twentieth century physics, for both those who find it genuinely
interesting, and those skeptics who still maintain a classical
conception of the metaphysics of modern technology. These
philosophies hold boundless possibilities for the capacity
of human advancements in science, and may prove to 'unlock'
many of the mysteries of the universe. If we are able to release
our previous conceptions of space, time, and matter, and allow
the uncertainty of the universe to maintain its ominous nature,
we may further evolve and improve (or destroy; depending on
how exactly one moralizes the advancement of technology) the
capabilities and capacities of our existence.
WORKS CITIED:
1. Infeld, Leopold The Evolution Of Physics (1938, 1966) A
Touchstone Book, Simon and Schuster Inc : New York
2. Greene, Brian The Elegant Universe (1999) Vintage Books
: New York.
3. Einstein, Albert Sidelights On Relativity (1923) Library
Of Congress Cataloging in Publication Data
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