INTRODUCTION
The special theory of Relativity,
proposed by the Jewish physicist Albert Einstein (1879-1955) in the early part
of the 19th century, is one of the most significant scientific advances of our
time. Einstein discussed his special theory of Relativity in his third 1905
paper entitled "On the
Electrodynamics of Moving Bodies." Although this paper challenged the foundation
notion about space and time, each of its parts was simply a response to an
important problem facing the physics community of Einstein's time. For,
Einstein's work on relativity, the photoelectric effect and blackbody
radiation, Einstein received the Noble Prize in 1921. However, this paper
attempts to discuss the special Relativity theory of Albert Einstein together
with its philosophical cum scientific implications.
SPECIAL THEORY OF RELATIVITY
Einstein's
special theory of relativity is based on two postulates, stated by Einstein in
the opening section of his 1905 paper. The first is the Principle of Relativity. It just asserts that the laws of physics
hold equally in every inertial frame of reference. That means that any process
that can occur in one frame of reference according to these laws can also occur
in any other. This gives the important outcome that no experiment in one
inertial frame of reference can distinguish it intrinsically from any other. For
that same experiment could have been carried out in any other inertial frame
with the same outcome. The best, such an experiment can reveal is motion with
respect to some other frame; but it cannot license the assertion that one is
absolutely at rest and the other in true motion. In other words, this postulate
holds that all physical laws are the same in whatever constant velocity you are
moving at.
Einstein's second postulate, The Light Postulate, asserts that light
is always propagated in empty space with a definite velocity C which is independent of the state of
motion of the emitting body. In other words, the speed of light is always the
same, independent of the motion of the observer or light source. These mean
that there is no absolute motion. If you are in a car going at 50 mph, there is
no way you can prove you are even moving. It could be the earth and everything
on it except you and the car is moving backwards at 50 mph, and if you wanted
to say that was happening, you would not be wrong, the law of physics would
back it up. All you can say is that one thing is moving RELATIVE to another.
SCIENTIFIC
AND PHILOSOPHICAL IMPLICATIONS OF EINSTEIN'S SPECIAL THEORY OF RELATIVITY
Albert Einstein's special theory
of Relativity though it is a classic, connotes some implications which can be
viewed from scientific and philosophical standpoints. Scientifically speaking,
one implication of relativity is the famous 'Twin Paradox', a hypothetical
situation in which one twin embarks on a journey through space while the other
twin stays on earth. When the first twin returns home after travelling at a velocity
close to the speed of light, he finds that he has aged by merely a couple of
years, while his brother on earth has been long since dead. This is because the
twin on earth has been travelling through space at a constant time (as the
earth orbits the sun), whereas the twin in the spaceship has had to decelerate
and then accelerate in order to turn back home, so he has not remained in an
inertial (non accelerating) reference frame. This paradox runs counter to our
commonsense view of time , but it is a natural consequence of relativity
theory.
On another note, unlike in the
Newtonian tradition where "a body in motion possesses an amount of energy
that is equal to one-half the mass of the body multiplied by the square of its
velocity,"[1]
Einstein's special relativity makes energy to be equivalent (or
interchangeable) with mass. Even a body at rest possesses 'rest energy' and the convertibility of energy with mass is
represented in his famous equation: E= MC2 (where E is energy; M=
mass and C= speed of light).
Furthermore, if the speed of light
is always the same, it means that an astronaut going very fast relative to the
earth will measure the seconds ticking by slower than earth bound observer
will. Time essentially slows down for the astronaut,- a phenomenon called Time
dilation.
On the other hand, one of the
philosophical implications of Einstein's special theory of relativity is the
substitution of space-time for space and time. This is consequent upon the
notion that time is somehow similar to the spatial dimensions. In other words,
space and time cannot be conceived separately because the notion of space
implies time.
EVALUATION
Albert Einstein's
theory of relativity is 'Special' in that it only applies in the special cases
where the curvature of space-time due to gravity is negligible. However,
special relativity implies a wide range of consequences, which have been
experimentally verified. They include; length contraction, time dilation,
relativistic mass, mass-energy equivalence, a universal speed and relativity of
simultaneity. It has replaced the conventional notion of an absolute universal
time with the notion of a time that is dependent on reference frame and spatial
position. Rather than invariant time interval between two events, there is an
invariant space-time interval.
Furthermore, Einstein's relativity
theory was presented as a principled, rather than a constructive theory. A
principled theory is one that begins with principles and then uses these
principles to explain the phenomena; a constructive theory starts with the
observations and culminates in theories that explain and reconcile those
observations. Nonetheless, Einstein's special relativity theory showed that
time and space are not a priori categories of human understanding; rather, they
are relative quantities that are defined operationally.
CONCLUSION
The special theory of relativity has a central place in
modern physics. It is the first port to call for philosophers and other
thinkers, seeking to understand what Einstein did and why it changed
everything. Also, it's essential content
can be grasped fully by someone merely with a command of simple algebra. In a
nutshell, Einstein's theory of relativity describes how to figure out what a
set of events will look like from one point of view, based on what it looks
like from another point of view.
BIBLIOGRAPHY
BRAITHWAITE, R. B., Scientific
Explanation: A Study of the Function of Theory, Probability and
Law in
Science. Cambridge:
The Syndics of the Cambridge University Press, 1953.
Encyclopedia
of Philosophy: vol. 5 & 6; Edited by Paul Edwards. New York: Macmillan publishing Co., Inc. &
The Free Press, 1967.
OGBOZO, C. N., Philosophy of
Science: Historical and Thematic Introductions. Enugu: Claretian
Communications, 2014
PHILIPP, F., Philosophy of
Science. New Jersey: Prentice-Hall, Inc. 1957.
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