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ife
, as we know is very beautiful. Now you are witnessing an alien attack on our
home planet theEarth. Are we destined for such an attack? Is our civilization
under the threat from other civilizations in outer space? Or, is it a pure
fantasy?
Come
let us view this planetarium show to find out more about life which may exist in
the universe apart from Earth.
In
1610, Gallelio first made use of the telescope to observe the sky. He saw
craters on the moon. After seeing this new world, Gallelio defiantly wondered
about the existence of life on those far away planets. Prior to him Bruno, a
famous astronomer also speculated about the existence of extraterrestrial life as it is called. It is learnt from
ancient literature that Epicurus, a Greek philosopher in the fourth century BC,
believed in an infinity of worlds, meaning other ordered systems beyond the
visible universe as it was then conceived.
Now
lets stop speculations and start logically to analyze to and understand
what is life and how did it evolve on Earth. The primitive earth was an
extra-ordinary laboratory, rich in water, reduced gases and a host of minerals.
The liquids and gases, interacted with these elements and also energy from ultra
violet radiation of sun, lightning and volcanic heat was plentiful. This made
the ocean turn into primodial soup. Gradually over a period of millions of years
life in its simplest form evolved.
In 1953, an American
chemist named Stanley M. Miller attempted to recreate the conditions of the
young planet in the laboratory. He filled the glass apparatus with warm ‘ocean’
and an ‘atmosphere’ composed of methane, ammonia and hydrogen gases. He sent
strong sparks through the gases to imitate lightning. After only a day, Miller
could detect amino acids in his miniature ocean. Later other experiments showed
that these amino acids could combine to form proteins. Under right conditions,
the proteins would even form microscopic balls. These spheres look like
bacteria. Such tiny protein sphere might have been the first ancestor of living
cell. This process can be compared with germination of seeds only when right
conditions are created.
Biologists,
however, find it hard to define life, though they have vast knowledge of living
things. They have difficulty locating the dividing line between living and
non-living things. For example, a virus is a lifeless particle by itself, but it
becomes active and multiplies rapidly when inside a living cell. The
Earth has an enormous variety of living things ranging from microscopic
bacteria to gigantic blue whales and towering sequoia trees. Living organisms
now include as many as thirty million species occupying nearly every nook and
cranny of earth.
According
to evolution theory, the first singled celled organisms appeared about
three or four billion years ago, soon after the earth crust had formed and
cooled. As time passed organisms that are more complex gradually developed,
specialized characterstics that helped them adapt to their environment. The
theory of evolution helps explain two fundamental facts of nature- the
tremendous variety of living organisms and their basic similarities. However
this theory is not accepted due to various drawbacks
Among
the accepted school of thoughts, Darwin’s theory is very popular. In 1858,
Charles Darwin introduced a theory of evolution that, in modified form, is
accepted by most scientists today. Darwin’s theory states that all species
evolved from a few common ancestors by means of natural
selection.
Dinosaurs
dominated the earth about 65 million years ago and their size ranged from as big
as a house or as small as a chicken. They lived and ruled the Earth for over one
hundred and sixty million years. Some claim that a comet might have crashed up
on earth and erased Dinosaurs from its surface. Others believe that Dinosaurs
became extinct since they could not adjust to the changing
environment.
After
knowing about how life might have originated and there by evolved on earth, let
us see how our beautiful cultural life varies from place to place as the
climatic and geographical conditions varies. Let us start from Kozhikode, or for
that reason Kerala. This place has contributed the Kathakali dance to the
cultural heritage of the country. Next,
our
neighbouring state Tamil nadu, which gave Bharat natyam. Leaving the southern
part, let’s move to the north and observe a scene from the celebration of the
festival Holi, while the northeastern India has
contributed Manipuri dance, Tagore’s literary culture at Santiniketan came from Bengal. After this turning our
eyes to the western India, a scene from Gujrat’s festive atmosphere. Let’s leave
India and Asia and have a tour to other continents. A view of the tribals of
Africa. Next moving to the American continents, let’s have a look at the busy
life of an American city. Antarctica expedition had taken human race to mingle
with even penguins, a rare species.
See
the night sky with full of stars. On a clear night, just observe the myriad’s of
stars in the sky. Further, we observe some bright objects which change their
position with respect to the fixed stars. These are the planets of our solar
system. As Earth rotates from west to east, these stars seem to rise in east and
set in west. Our ancestors, to remember the portions of sky, imagined beautiful
patterns among those stars in the sky. These patterns are called constellations.
Look at those stars in the form of a W, or inverted M. It’s the constellation of
Cassiopeia. Can you see that small cloudy patch? It’s at a distance of two
million or two followed by six zeros ,light years or equivalently twenty one
followed by twelve zeros kilometers away from us. It is one of our neighboring
galaxies called Andromeda. Look at those seven stars. Some thought it in the
form of a plough, some in the form of a bear, some in the form of a spoon.
Accordingly it was know as plough , Great Bear and Big Dipper respectively. Indians
gave name of its seven sages corresponding to the seven stars and called it as
Saptarishi. A professional astronomer calls it URSA MAJOR. If you consider those
two stars and extend it forward, you will reach that star there. It is our north
star or our pole star; which is along the imaginary axis of earth’s rotation.
So, all stars describe a circle in the
sky with this star at its central axis. Pole star never rises or sets
from a particular location on the surface of earth. Further if we take those
stars and maintaining same curvature
, draw an imaginary line, we reach that star there called Arcturus in the
constellation of Bootes. Further, look at those stars in the sky. They form the
heavenly twins, called the constellation of Gemini or the mithuna rashi. Look there, those stars form the
constellation of Leo, the lion. In India its called Simha
rashi.
Look
at that bright object, that is Mars, which in many ways resembles the earth. The
Romans called this Orange-red planet Mars, after the god of war. Its surface is
covered by rusty red rock and dotted with huge canyons and volcanoes, polar
icecaps and mountains. About a century ago, an Italian astronomer called
Schiaparelli sketched the Martian surface by observing through a telescope. He
developed the theory that these lines were really canals, built by a Martian
civilization to transport the planet’s dwindling water supply. Many people
wanted to believe him, but in 1965 Mariner 4 spacecraft passed near the planet
and saw no sign of any such construction. Further Mariner 10 landed on Mars,
collected a few samples, andour scientists after analyzing them concluded that
there is no life in Mars. And do you know in the year 1938, many people in the
United States turned on to their radios as actor Osron Welles narrated the
dramatic science fiction story “The war of the Worlds” by H.G.Wells. The story
sketches the invasion of Martians on Earth. Before the program was over,
millions of people believed that Martians were really invading
Earth.
During
the twentieth century many space probes were sent in the outer space, and by
analyzing the detailed
Images
they transmitted to earth, the astronomers and scientists have globally
concluded that the conditions of the other planets are not at all favorable for
the development of life in the form known to us. Nevertheless, some satellites
of Saturn have to be probed in details for more information. Recently, studying
the images transmitted by the Galelio space craft, its learnt that there may be
liquid water beneath frozen ice surface under Europa, a moon of
Jupiter.
Like
our solar system, there are many other stellar system. About forty extra-solar
planets have been discovered till date. In October 1995 Michel Mayor and
Dider
Queloz of Geneva observatory in Switzerland reported about finding the first planet near the star
51-pegasi , there, in the constellation of Pegasus. During June 2000, American
astronomers have discovered a planet about twice the mass of Jupiter orbiting
the star Gliese 876; one of the Sun’s nearest neighbors at a distance of fifteen
light years away.
According
to Inflatory theory, there exist billions and billions of expanding universes,
can you imagine!! They formed along with our universe and developed in the past
four and half billion years. Today our universe has reached a radius of fifteen
billion light years due to expansion of the universe as suggested by astronomer
Hubble. This is what we call visible universe. Therefore, our universe is only
one among the billions of billions of universe. In all the other universes,
there are objects in mutual visible contacts, and we will never be able to see,
or know anything about them as they are too far for light to reach
us.
Nevertheless,
our universe contains billions of billions of stars. Astronomical calculations
shows that there exist altogether one thousand six hundred million million
million stars exactly similar in age and mass to the sun in our universe. Of
these about fifty percentage are double stars and remaining have a
planetary system. This give eight hundred million million million earth like
planets in the universe. Then logically there are millions and millions of
intelligent civilizations like us in the universe. A rough estimate of the same
was given by Frank Drake in his famous Drake’s Equation. According to him, the
optimistic estimate is around one billion civilization.
Then
the question which comes to our mind is that why are we not meeting them. The
problem is the distance. With this background how can we say that we are alone
in the universe? Probably we have to believe that we are alone until we meet and
shake hands with some alien.
Actually,
the research for extraterrestrial life commenced with the investigation of
meteorites. The
one
found in Allen hills of Antatrica, called ALH8001, has revealed the presence of
numerous amino acids that are not found in the living organisms on
Earth.
Carbon
is the building block for the known life form to us. However, scientists freely
speculate other possible life forms based on silicon which is chemically similar
to carbon.
There
were reports of sighting aliens and disc like objects in the sky. These objects
are popularly called UFO or unidentified flying objects. One such incident goes
like this,
“
I was standing near my window at about midnight. Actually, I was not getting
sleep. Suddenly I saw an object high in the sky with pulsating light. At first
it was stationary, and then it started descending and after a few moments I saw
a huge spacecraft landed in the paddy field near my house. As I just turned my
eyes I saw three tiny objects near the door of my bedroom. I started fainting.
The next thing, which I remember was a huge laboratory, may be inside the
spaceship. Some tests were being carried out on me. After a few moments, I found
myself standing near my window. “
However,
none of these reports were found to be supported by physical evidences. Several
official investigations were conducted both in USA and in the USSR, while they
were satisfied that UFOs do not exist, there were incidents they could not
explain.
However,
many were explained as the observation of weather balloon, the planet Venus and
so on.
Nevertheless,
this did not stop the Hollywood filmmakers like Stephen Spilberg from imagining
an extraterrestrial creature in his film ET.
However,
our scientists have never lost their enthusiasm and today we are using other
means of communication- the bottle in the sea, or more precisely in space.
Prompted by Carl Sagan, our Civilization has already released four of these, two
in pioneer 10 and 11 and two in the Voyager 1 and 2 spacecraft: these four
messengers left the Solar System and are going on through deep space, covering a
distance equivalent to our separation from the nearest star in eighty thousand
years. Information
on
our civilization is conveyed in engraved plaques or in Veda discs. Further, the
radio telescope at Arecibo in Puerto Rico as a part of SETI , Search for Extra
Terrestrial Intelligence is transmitting radio signals to any possible
civilization, which might live. The former soviet initiated project CETI (
Communication with Extra Terrestrial Intelligence). In this project the
arrangement was to listen to near by 600 stars on 21 centimeters wavelength. The
results were found to be negative.
Our
planet is enveloped by an atmosphere, which allows only two portions of the
electromagnetic spectrum to pass through it. They are visible radiation and
radio waves. As is well known from the laws of physics, that the intensity of
visible light decreases as the distance from the source increases, visible
radiation’s intensity would be very feeble from any other intelligent
civilization. For this reason. Only radio telescopes are used for the
extraterrestrial research project.
India
too is arranging and devising several experiments for understanding the origin
of life. Recently on may22, 2000, Dr. J.V.Narlikar announced at a press
conference at Trivandrum that a plan is worked out to fly balloons from balloon
facility center of ISRO to collect samples from various layers of our atmosphere
at different altitudes.for analyzing the presence of microorganisms transferred
to the high altitude of earth’s atmosphere, may be by a passing comet’s tail
according to a theory proposed twenty-five years ago by Dr. Wikramasinghe and
Dr. Boyd .
As
Prof. Govinda Swaroop, the chief architect of Giant Meter Wave Radio Telescope
(GMRT), Pune, said that
There
has to be life out there near by some of those stars, otherwise it’s awful waste
of space. May be let us also sit back and wait for some alien to contact
us.
Ladies
and gentleman, now you may feel that truly we are not alone in the universe.
However, the search for our extraterrestrial life. Until concrete evidence
emerges, it is left to your guessing and conclusion
Thankyou
and Goodbye.