THE MAN BEYOND TIME
INTRODUCTION
One of the
towering achievements of 20th century physics is the theory of
relativity by Albert Einstein. Newton’s theory of gravitation was soon accepted
without question and it remained unquestioned until the beginning of this
century. Then Albert Einstein shook the foundations of physics with the
introduction of his theory of relativity. These theory transformed theoretical
physics and astronomy during the 20th century superseding a 200
years old theory of mechanics created primarily by Isaac Newton.
Let’s go
through the mind- blowing theory proposed by Albert Einstein….
THE PIONEER OF MODERN PHYSICS
Albert Einstein was born on March 14, 1879 in Germany
to Jewish parents. Einstein was not a very bright student. He even had problems
with his speech. When he was 5 years old, Einstein saw a magnetic compass and
marveled at the needle that kept moving with an invisible force. At age 12, he
found a book on geometry which he read over and over again. He became
fascinated by math and taught himself. During 1905, often called Einstein’s “miracle year”,
he published four papers in the ANNALEN DER PHYSIK, each of which would alter
the course of modern physics. In 1921, Einstein won the noble prize for physics
for his explanation of the photoelectric effect, since his ideas on relativity
were still considered questionable. And he died on April 18, 1955.
VICTORIOUS FAILURE
Michelson Morley experiment is the most brilliant
failure in the all history of science. It was designed to detect the motion of
earth through the lumineferuos ether. Ether was the invention of 19th
century’s physicists to explain how the light was transmitted through empty
space between sun and earth. The legend about Michelson Morley experiment is
that it’s just deeply rooted as the story about Isaac and the apple. Michelson
and Morley did their experiment and proved there was no ether and so Einstein
was forced to invent the theory of relativity in order to explain the net
result.
SPECIAL
THEORY OF RELATIVITY:
Special theory of relativity is generally accepted
and experimentally well confirmed physical theory regarding the relationship
between space and time. It is based on two postulates:
The laws of physics are invariant in all
inertial systems. The speed of light in vacuum is the same for all observers,
regardless of the motion of the light source. It was originally proposed by Albert
Einstein in paper published 26 September 1905, titled “on the electrodynamics
of moving bodies”. The inconsistency of
Newtonian mechanics with Maxwell’s equations of electromagnetism and the
lack of experimental confirmation for a hypothesized lumineferous ether lead to
the development of special relativity, which corrects mechanics to handle
situations involving motions at a significant fraction of the speed of light.
As of today, special relativity is the most accurate model of motion at any
speed when gravitational effects are negligible. Special relativity implies a
wide range of consequences, which have been experimentally verified including
length contraction, time dilation, relativistic mass, mass- energy equivalence,
a universal speed limit 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 special position.
GENERAL THEORY OF RELATIVITY
General theory of relativity is the geometric theory
of gravitation published by Albert Einstein in 1915. General theory of
relativity explains the law of gravitation and its relation to other forces of
nature. It applies to the cosmological and astrophysical realm; including
astronomy. General relativity generalizes special relativity and Newton’s law
of universal gravitation providing a unified description of gravity as a geometric
property of space and time. Some predictions of general relativity differ
significantly from those of classical physics especially concerning the passage
of time, the geometry of space, the motion of bodies in free fall and the propagation
of light. Examples of such differences include gravitational time dilation,
gravitational lensing, the gravitational red shift of light, and the
gravitational time delay.
Some of the consequences of general relativity are:
- Clocks run slower in deeper gravitational wells. This is called gravitational time dilation.
- Orbits précis in a way unexpected in Newton’s theory of relativity.
- The ray of light bend in the presence of a gravitational field.
- Rotating mass “ drag along” the space time around them ; a phenomenon termed "frame-dragging".
- The universe is expanding, and the far parts of it are moving away from us faster than the speed of light.
CONCEPTS IN A NUTSHELL
Ø Space
Time: Einstein realized that space and time are relative. An object in motion
actually experiences time at a slower rate at one rest.
Ø Relativity
of simultaneity: Two events simultaneous for one observer may not be simultaneous
for another observer if the observers are in relative motion.
Ø Time
dilation: a clock that is moving relative to an observer will be measured to
tick slower than a clock that is at rest in the observers on frame of
reference. That is moving clocks are measured to tick more slowly than on
observers stationary clock.
Ø Length
Contraction: The length of object moving at relativistic speed undergoes a
contraction along the dimension of motion. That is a moving objects length is
measured to be shorter than its proper length, which is the length as measured
in the objects on rest frame.
SOME INTERESTING FACTS
What if you travelled faster than the speed of light?
Is there really an absolute frame of reference?
Is time an illusion?
What if you travelled faster than the speed of light?
As an object approaches the speed of light its mass
tends to infinity. So does the energy required to move the object also tends to
infinity, which is not possible. For this reason, no normal object can travel
as fast as or faster than the speed of light.
Is there really an absolute frame of reference?
General relativity tells us that there is no
absolute frame of reference. Actually it tells us that all the frames are
relative, which is but not the same as there is no absolute frame.
Is time an illusion?
Time is actually relative and flexible and according
to Albert Einstein the dividing line between past, present, futures is an
illusion. Time has not always existed, the theory relativity suggests before
the big bang, 13.75 billion years ago, time and space did not exist.
DO YOU KNOW?
Ø All
though Einstein will forever be associated with the theory of relativity, his Nobel
Prize was actually awarded to him for his observation of photoelectric effect.
Einstein theory of relativity was not completely accepted by scholars’ until
many years.
Ø 1905
is often referred as Einstein’s miracle year. In that year Einstein published
four different ground breaking papers, which laid the foundation of modern
physics.
Ø The
discovery of the hugely important equation E=mc2, which showed that
energy and matter are interconveratble is considered to be his biggest
accomplishment, but there is evident that another physicist published this equation
a year before him.
Ø Einstein
could have lived longer when he suffered a burst blood vessel, Doctors told him
surgery could have saved his life. But he declined the procedure, saying “It is
tasteless to prolong life artificially”.
Ø What
were the last words of Einstein???
His last words will never be known. He said them in German, but attending nurse didn’t speak German and couldn’t recall what he said.
EINSTEIN’S QUEST FOR A UNIFIED THEORY
After having become famous for several brilliant
breakthroughs in physics, including Brownian motion, photoelectric effect and
the special and general theories of relativity, Einstein spent the last 30
years of his life on a fruitless quest for a way to combine gravity and
electromagnetism into single elegant theory.
INCOMPLETENESS OF THEORY RELATIVITY
General relativity as emerged as a highly successful
model of gravitation and cosmology. However there are strong indications that,
the theory is incomplete. The problem of quantum gravity and the question of
the reality of space time singularities remain open. General relativity is
incomplete since it does not include the gravitational radiation reaction force
and the interaction of gravitation with charged particles. The discovery charge mass interaction
establishes the need for unification of electromagnetism and gravitation and
would explain many puzzles. Observational data that is taken as evidence for
dark energy and dark matter could indicate the need for new physics. Even taken
as is, general relativity is rich with possibilities for further explorations.
THE MAN WHO BEHIND:
Ø Photons:
he discovered that light is made up of small particles called photon and was
awarded the Nobel Prize for physics in 1921.
Ø Bose
Einstein condensate: Einstein discovered a state of matter with another scientist,
Satyendra Bose. Today it is used in things like lasers.
Ø Atomic
bomb: not directly connected with inventing it, but his theory of relativity is
connected with the invention of the atomic bomb.
Ø Global
positioning system such as GPS, GLONASS and the forthcoming Galileo must
account for all of the relativistic effects.
Ø Satellite
based measurement need to take into account relativistic effects
Ø Nuclear
plants: relativity is one of the many reasons that mass and energy can be
converted into each other which is how nuclear power plants work
Ø Study
of black holes, supernovas and other space phenomena
Reference:
[1] Arthur
Beiser : 2005, Concepts of modern physics, New Delhi, Tata McGraw-Hill
[2] J.C. Upadhyaya: 2003, Mechanics, Agra,
Ram Prasad Publications
[4] https://www.space.com
SUBMITTED
BY:
Ashna PV
Anusree A
Baby Athira
Deekshitha kumari
Dakshayani P
No comments:
Post a Comment