Just as everything has a beginning, its end is an inevitable consequence. The journey of our universe began with the Big Bang which is a proven fact. This journey too will one day lead to its end through its final state. Scientists have been speculating about this last state of affairs, but since it is a future event, it is not possible to say for sure. Among the various hypothesis, the one that is most practiced among scientists is the Big Crunch. Today we will try to know and understand something about this hypothesis.
The
hypothesis was first introduced in 1948 by George Gamow, a scientist born in
the then Russia (now in Ukraine), and later the citizen of United States, and
it was later mathematically popularized by John Wheeler. One thing is very important
here and that is this hypothesis has been developed in line with Albert
Einstein's General Theory of Relativity. (According to Einstein's General
Theory of Relativity, what we perceive as the force of gravity is actually
derived from the curvature of space and time.) In simple word, the origin
of the universe, that took place after the Big Bang, will go to its ultimate
consequence through the unavoidable cosmic event, known as Big Crunch.
Since
the Big Bang, space has been expanding at a tremendous rate. The speed of this
expansion is greater than the speed of light (The speed of light is
2,99,792.46 meter per second or 107,92,52,856 km per hour). The Big Bang
happened 1,380 crore years ago from today. If the distance is to be understood
with the help of the speed of light, then the expansion of this universe should
be 1,380 crore light years wide. (Light years: The distance that
light travels in a year) But in reality, the expansion of the universe is
at least 5 times more than the result of calculation and it is now 9,300 crore
light years. This means that our universe is expanding 5 times faster than
light and the rate of expansion is still increasing. As a result, every object
in space is moving away from each other little by little. Maybe that's why the
moon, the only satellite of the earth, is moving away from the earth little by
little. Scientists have calculated that the moon moves 3.8 centimeter or 1.5
inches away from the earth every year. Not only the moon, every year our earth
is moving 11 to 19 centimeter away from the lord of this solar system, sun, on
average. Thus the distance between each member of this solar family and its
surrounding objects is increasing with time and the area of the solar family
is increasing every moment of the day.
But
this is not a fact that will last forever. As this expansion of the universe
continues with the passage of time, there will come a moment when the expansion
of this universe will continue to slow down and at some point of time, it will
come to a complete halt. At that time, the retrograde activity of expansion
will begin, that is, the universe will then shrink and seek to return to its
former state. If an event can be compared to this event, it can be said that if
an object is thrown upwards while standing on the earth, then, the maximum
velocity, at the moment of throwing, will decreasing as time goes on. Once the object reaches a
certain height, the velocity will become zero and starts to go down again and
in this case its velocity will start to increase with time. When the object
reaches its maximum velocity, it will fall to the ground. This contraction of
the universe will create a black hole-like situation, the final state of the
gigantic stars, across the space. At high velocity, all the objects in this
universe will run towards a point of infinite density. This is the point at
which the universe was created after the Big Bang, which is called the Point of
Singularity. This is the ultimate fact of the Big Crunch hypothesis.
Now the main question is what exactly is the cause of this great contraction? Scientists, using maps of the universe and mathematical analysis, have discovered that the density of matter in per unit area in the universe is quite high. If the amount of matter is more, then according to the property of Physics, there will be more amount of gravitational force. Initially, an object travels a certain distance under the impact of kinetic energy, but the gravitational force, generated by the extreme density of matter in per unit area, will exceed the expansion of this universe. By ignoring this gravitational force, no cosmic object or even light probably will obtain the Escape Velocity, required to escape from this universe. (Escape Velocity: The minimum velocity required for an object to come out by avoiding the intense gravitational force of a cosmic object.) Under the influence of this gravitational force, the expansion of the universe will stop and the contraction of the universe will start due to its reverse action and finally the cosmic gravitational collapse will take place.
Scientists
have abbreviated this whole system as the Big Bounce in which the universe is
expanding through the Big Bang and again the contraction of the universe will
be occurred through the Big Crunch. If a ball can be pushed with enough
potential towards ground from a certain height, according to Newton's third
law, the ball will again gain some height due to the same and opposite
reaction, imposed by ground. From this, the scientists like to imply that
nothing in the universe is permanent, but that the effect of two opposite
actions will create different conditions. Maybe the universe is eternal but its
advent and disappearance will continue through the Big Bang and the Big Crunch.
Although
the scientific community is generally convinced of the Big Crunch, but it has
raised questions in their minds about a number of issues which have not yet
been resolved theoretically or mathematically. So scientists are still somewhat
skeptical about the Big Crunch. This Big Crunch was extensively studied in the
late 1990's and early 2000's. Maps of distant Supernovae and Cosmic Microwave
Background show that the velocity of expansion of our universe has not only
slowed down, but has continued to increase over time, over 1,380 crore years.
When a massive star runs out of fuel, iron is produced in the core of the star
and its atomic fusion reaction stops, then that star explodes with all its
energy in space, turning into a Neutron Star or a Black Hole. This explosion of
stars is called Supernova or Supernova-Explosion. If the light of all the stars
in the sky could be obscured in any way, it would be seen that there is a
glimmer of dim red light all over the sky. This light is the last radiated
light, created after the Big Bang called Cosmic Microwave Background.
At
first, scientists assumed that there were basically two forces at work in this
expansion of space, the first being the intense external motion of objects
obtained by the Big Bang and the second being the intense gravitational force
between the various galaxies of the universe. But the famous British
mathematician Robert Penrose later said, after his long research, that this
expansion will continue until all the matter in the universe is depleted. In
other words, this phenomenon will continue as long as light and time exist in
this space. When all the objects in space will be eroded, there would be no
distance or time relationship between any objects in this universe. However, it
is not yet known whether Dark Energy has anything to do with this expansion of
space. If the Dark Energy works here, there may not be the Big Crunch. It
should be noted here that Dark Energy is a theoretical form of energy that
works against gravity throughout the universe and is believed by many to be
responsible for the expansion of the universe. In researching this, the Chandra
X-ray Observatory observed various distant and near places in space and has
given the information that the amount of this Dark Energy is almost the same in
all places in space.
The
relationship between the expansion of space and the decay of objects also
suggests that, analyzing Cosmic Microwave Backgrounds can provide a clue to the
decay of objects and Big Crunch of the universe, but no progress has yet been
made. The British scientist Paul Davis tried to determine the time of this Big
Crunch through his mathematical model. There he estimated that the moment of
that Big Crunch might come 100 billion or 10,000 crore years from now.
According to him, first small sized, then small and medium sized and finally
giant galaxies will continue to merge with each other. As galaxies approach,
collisions between stars of different sizes will occur more frequently, the planetary
system of the stars will be completely destroyed, the temperature of Cosmic
Microwave Background will continue to rise again and that temperature will
eventually reach the level of an M-class star. (The temperature of M class
stars usually ranges from 2,126 degree Celsius to 3,426 degree Celsius)
This temperature will be maintained until all the matter in the universe has
completely evaporated.
At
this temperature, the atoms of all objects in space will begin to disintegrate,
be it solid planets, satellites, bright comets, or gaseous hydrogen. These
disintegrated particles will then start advancing to a particular point. Just
like when a large star turns into a black hole, the surrounding objects in the
functional area of that black hole move towards the black hole. At that time
all the space will be transformed into an infinite black hole where infinite
density and infinite temperature will be created. After this the space will
begin to shrink more rapidly and the whole universe will become a tiny dot.
Scientists estimate that the volume of that point will be smaller than the
smallest particle of any molecule, quark. This point will be called Pont of
Singularity. After the Big Bang, the entire universe was created from this
unique point, and after the Big Crunch, the total universe will be destroyed
and disappear at that same unique point.
According
to the Big Bounce hypothesis that the scientists talked about, there would be a
favorable environment like the Big Bang, there would be a Big Bang again, dust,
hydrogen gas, nebulae, stars, small and big galaxies would be reborn, planets,
comets and meteors would revolve around the stars. Satellites will reappear
around the planet. Different kinds of invisible waves, visible light, solar
particles will spread all around the universe, in the midst of all these events,
new life will blossom in multiple places in a suitable environment at the
farthest unknown end of space. All the history of life will be rewritten, the
unknown will be tried, a new struggle to conquer everything will begin.
DECLARATION: All The Images Have Been Sourced From Google.
