Astrology
Relativity Revolution
A revolution occurred in natural philosophy during the
first decade of 20th century. Many scientists accept
it respecting its intellectual concept and changements
in mass rules and believe in its priority in
comparison to Copernicus and Galileo scientific
revolutions. During this period two scientific
theories presented competing with each other which
are; Relativity and Quantum theory. These theories
were significantly different from pervious ones, which
were presented by J.C.Maxwell, W.T.Kelvin, and R.J.E
Clausius. These new theories were fundamentally
different from principles and hypotheses of Newton’s
mechanics. This theory not only includes mathematical
complexities but also its inference and mental concept
is very difficult. In 1905, Albert Einstein presented
the Special Theory of Relativity for the first time.
At that time, he used easy mathematical equations. In
1919, Einstein presented General theory of Relativity.
Contrary to previous time, he used complex,
mathematical formulas.
The term “Relativity” is derived from “Relative”
theory. In fact, each of physical units which is used
for natural phenomena are relative. It means, weight,
velocity, acceleration and even time are relative
factors. To understand better, a couple of examples
are used. In Newton’s mechanics, weight on the Earth
is explained as a force that is exerted from the Earth
toward objects and pulls them with acceleration of
“g”. You may ask, “Where?” Weight of a person in an
elevator going down is different from an elevator
going up.
Another example is; Majeed and Farhad are friends
driving a car with a speed of “V”. Their destination
is Ahmad’s house. At this time. Ahmad sees Majeed’s
car from the top of his house. He calculates Majeed’s
car velocity from there by a special device. The
velocity is V (which is equal to car velocity). At
this moment, the car of Ahmad’s father bearing
constant speed passes by Majeed’s car. When this car
passes by, the device which is in the car of Ahmad’s
father indicates the speed of Majeed and Farhad as
follows; U=V+P.
When these two cars pass by each other, Ahmad asks
Majeed to measure Farhad’s speed. Majeed says that it
is a funny question. Because it is quite natural that
Farhad’s speed is zero. He has sat close to me
without any movement. Ahmad gives a call to his father
and asks him what the speed of Majeed and Farhad is in
accordance with his calculator. Ahmad’s father says,
“The speed of Majeed and Farhad is U=V+P.”
At this stage, Ahmad thinks how it is possible a
person having three different speeds whereas he has
sit in car without any movement. Ahmad is not
familiar with the principle of cinematics a lot.
Therefore, speed is also relative.
According to Einstein point of view, relativity of
velocity is more dependent on validity of Relativity
Principle than Ether Theory. Relativity Principle
says,”Natural laws in reference’s frameworks are
similar.” After presentation of Relativity Principle,
Einstein involved in two fundamental themes as
follows;
1.Relativity Principle is correct for all natural
events.
2.The velocity of light in vacuum, regardless of light
source movement is equal to c.
The Second Thematic Principle of Einstein is much more
complete than Newton’s mechanics thought and Galileo’s
cinematics. Based on the principles of cinematics, if
two moving objects go toward each other with a
constant speed, when they reach each other, their
speed is the sum of their two speeds. But in
accordance with the relativity theory the situation is
different. If light radiates to a point, the static
and mobile observers who move toward the source with a
speed of V, calculates the light speed “c”. These two
principles have two surprising results;
1.Time dilation coincidence
2.Twin paradox
3.Gerald-Lorentz contraction
_
1.Time dilation coincidence
In accordance with Newton’s mechanics time is an
absolute parameter. It means, time goes by throughout
the world regardless of the governing conditions in
the environment. Einstein believes vice versa. At
this point, Einstein and Newton points of view are
separate from each other. Einstein point of view
regarding time is; Time is not absolute. To prove
this opinion, he used his second thematic principle.
An example to prove his hypothesis is as follows;
Two flash lamps are available in two points of A and
B. An observer is between A and B. He observes both
flashlights at the same time. If observer is closer
to A , he will observe the light of A sooner than B.
If observer is closer to B , he will observe the light
of B sooner than A. Therefore, it seems that these
two events have not occurred at the same time. Now,
one of the most famous consequences of this theory,
which is time dilation, is verified. Time dilation
means that a clock in mobile conditions seems to work
slower than static ones. Two clocks were provided
with similar specifications. Two mirrors were also
prepared. These mirrors are parallel two each other
bearing a distance of “d” from each other. On the
other mirror has a source, which can radiate light
from itself. When this ray of light reaches the other
mirror reflects and reaches to the radiation point.
One of the clocks indicates the duration of light
return between the two mirrors. It means, this clock
indicates time in terms of this formula; t=26:c.
One of these clocks put in a static place. It
indicates, time unit, which is equal to “t”. The
other clock is moved with high speed of “u”. In this
case, the distance of light return is more than 2d.
Because this clock is displacing fast. Therefore, it
can be assumed that the light in its going and
returning ways has a broken route. Infact, in mobile
conditions, time unit is bigger than static
conditions. It can also say that clocks in mobile
conditions work slower than static conditions.
2.Twin paradox
In Relativity Theory, time dilation leads us toward
Twin Paradox. After 50 years from presentation of
Einstein’s Relativity Theory, this Paradox is still a
case of discussion for senior scientists. Definition
of this case is presented by the following example;
Assume a twin. One of them decided to go to a far
planet with a spacecraft by a speed close to the speed
of light. This journey takes 70 years in terms of
calendars that we have on the Earth. When he returns,
his brother who was on the Earth is at 90, but he is
29 years old.
3.Gerald-Lorentz contraction
Time dilation is one of the most significant results
in Relativity Theory, which caused to present the
Gerald-Lorentz contraction. Observer “O” is in static
condition and wants to calculate the length of a tube.
The method of measurement is as follows;
An object having constant speed of V is thrown from
one end of tube toward another. The duration of the
movement of this object is calculated in accordance
with cinematic formula. The length of tube is L
(L=t.v).
Observer Z in a mobile condition calculates the tube’s
length. To measure the length of tube, the method of
observer O is used and length of tube is L’
(L’=t’.v’).
In accordance with former relativity results (time
dilation), time for a mobile situation is slower than
a static condition. Then t>t’ and as a result L>L’
indicating tube length contraction in mobile
conditions. Inference of such a condition is very
tough. But Lorentz believes in changement of
electromagnetic forces of atoms in high speeds.
Unfortunately, scientists have not been successful to
test Gerald-Lorentz contraction in practice. One of
the results of the Special Theory of Einstein in
contrast with cinematics that is; addition of speeds
which is suitable for mathematical problems.
E=mc² is one of the most important equations that
Einstein used it in one his scientific eassays and
presented it without mathematical complexities. He
only used a kind of logical deduction during the
presentation of this physical concept. In his essay,
he wrote; If an object loses its energy in form of
radiation, its mass decreases about E/c^2. If an
object loses its mass, the released energy will be
calculated by E= mc². This energy is in form of
radiation, and M is the lost mass.
During nuclear reactions, particularly fission, some
parts of nucleus mass converts to radiation energy.
Ofcourse, opposite to this equation can be correct.
It means, if sufficient energy is collected, a massive
object will be produced. One of the most important
results of mass-energy equivalency is changement of
mass in the speeds near the light speed. Mobile
object mass moving with a velocity near the speed of
light is much more than its mass when it is stable.
Today, in the laboratories, energy will be given to
electrons and their speed can reach close to the speed
of light. In these tests, it has been proved that the
mass of electrons is increased in accordance with the
Relativity Theory of Einstein. In the meantime,
slowliness of passing time in mobile conditions in
comparison to static ones has been proved by atomic
clocks (Cesium).
In 1919, Einstein rectified and generalized his
Relativity Theory and presented the General Theory of
Relativity. Contrary to the Special Theory of
Relativity, the General Theory of Relativity comprises
complex mathematical equations. One of the
predictions of this theory is; “In a very strong
gravitational field, clocks work more slowly. Light
is also deviated in these kinds of fields.” This
theory could solve many of enigmas regarding Black
Holes, the life of planets and stars, energy of stars
and galaxies and the density of whole universe.
Black Holes do not experience everlasting contraction
