Thursday, December 31, 2009
Ever since man began to search into the deep outer space in search of Intelligent life in the universe. For a quite long time our scientists and astronomers are in search of extra terrestrial intelligence. This search was started from early sixties and still continuing. In 1960 the leading scientists by that time, Philip Morrison and Gluseppe Cocconi wrote an article in the most famous British Journal "Nature" about the SETI.
In that article they had mention that we should listen to certain radio frequencies to intercept messages that might be arrived from outer space livings and they concluded that the extra terrestrials must be exist some where in the universe and we will be able to see them and communicate to them one day in future. But no proof arrived.
By the same time two stares namely TAU CETI and EPSILON ERIDANI were pointed out by Frank drake a astronomer in Virginia. They were about 12light years away from the earth.Following the American scientists the Russian scientists tried their part and on 12th April 1965 they received a strong radio signals with high intensity but later they found that they were emanated from the quasars in the distance galaxies.
From sixties to end nineties there were about fifty to sixty listening programmes were conducted by the scientists and astronomers but all ere futile.The frustrated scientists and NASA abandoned the programmes because of the financial hurdles.
After the Apollo 11 mission was successful the NASA again started the projects with the new name MEGA-SETI and they have announced that they had received 164 signals from the outer space. But most of the scientists argued that there could not be extra terrestrial and few argued that we are only primitive to notice the non earthy intelligences.
Many scientists and biologists are unfavour to the extra terrestrial livings because they have so many doubts, firstly they don't believe that life is a common thing. secondly they argued that life in our planet is an accidental happening in the past and so that cannot be occur in the outer space. Last but not the least they argued that humans are an idea ltype that can not be copied.
Most of the stars are of so many light years away from us so the signals will take a long time to reach us and hence the debate will continue till our life time
Hence quite interestingly I wish to put a comma for this debate why because it is an unending one,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Thursday, December 24, 2009
Lac is a resinous substance secreted by a crimson-red, scaly tiny insect called the ‘Laccifer Lacca’. This insect about 0.5 mm long lives and thrives on the shoots of Lac trees and Ber trees.The other name of lac tree is Kusum. Lac is also obtained from Palas and the Ber trees also. The Lac obtained from the Lac tree is considered to be the best. There are four croups of lac named after the months in which the collection of each crop begins.
Lac-popularly know as shellac- has been known to man from very early times. Until the aniline dyes were introduced to markets, man used to get crimson-red dye from crude lac, which was utilized for coloring wool, silk and leather. Besides, it was used by women as Allta- a red colored liquid- to decorate their hands and feet.
Lac is used in the manufacture of gramophone records, electrical appliances, adhesives cement, printing ink etc.
The earths speed of rotation was slow down but the rate at which it takes place is very very small and it can not be accurately measured in a small interval of time. In 100 years or more a day or night will be two milliseconds longer. Now our earth takes 24hours to take one complete rotation on its own axis but about 400 million years before it was about 400days long.
Here we gave to remember again the moon is revolving around the earth more slowly and moves away from the earth few centimeters per year. The interaction of moon and earth are the result of the above interrelated phenomena.
we know gravitational pull of the moon and sun cause tides. Apart from these two the centrifugal force of the earth is also a reason for it. The height of the tides depends upon the shape of the coast, depth of the ocean and the shape of the Ocean bed.
The movement of water masses and tides makes some friction on the earth crest which absorbs some energy of the earth which works like a brake and slow down the earth's rotation.
As some time in future our planet will slowed its rotation and it will lose its own satellite moon. Further, after 4 thousand million years the earth will stop its rotation on its own axis which will result in dividing into two halves extreme hot and extreme cold region.
Friday, December 18, 2009
Wednesday, December 16, 2009
Tuesday, December 15, 2009
No other planet in the solar system possesses such a large satellite like moon. The first person to develop a theory about the moon was the scientist George Darwin son of the most famous Charles Darwin. He hold the view that the moon and the earth had once been very closer together than now. He thought that they had been hold together as a single planet revolving at a high speed around its own axis with a time taking less than two hours per rotation.
By that time the earth was molten and with high temperature. As the speed of rotation was high the earth bulged at the equator. The centrifugal force gradually caused a drop of terrestrial matter to detach itself and fly out into the space. This piece of the earth becomes moon, which continues to revolve around the earth as the satellite.
As a proof for his theory, Darwin shows the Pacific ocean which is shaped like a bowl. What he says is Pacific ocean is a scar left behind when the moon detached away. For most of the years the Astronomers though that Darwin's theory was more or less correct, but however later realise that the separation of moon from the earth could not have taken place in the way he described.
Then another theory was framed. The moon also was a small independent planet in the solar system when the solar system was formed however on one of its orbits it came a bit closer to the earth and it was influenced by the earth's gravitational pull and forced to follow the earth's orbit.
In 1960, a new hypothesis Accreation theory was framed according to this, when the solar system was young numerous planetary embryos, disintegrated near the earth. The pull of the earth caused the embryo to form a ring around the earth. Since the particles attracted one another and they began to cluster together finally forming the moon.
None of these theories was satisfactory to the scientists. The chemical composition of the moons surface differ from the earths crust. On the moons surface there is no alkali metal such as sodium, potassium etc but heat resistant oxides of aluminium and calcium are abundant which proved Darwin theory was wrong and the rock analysis further revealed that moon contains only 10 percent of Iron compared to th30percent of Iron content of the earth. Hence this proved capture theory and growth theory are wrong.
The origin of moon still present mystery we know that our planet and moon are of the same age. Further we know that our own satellite functions as a climatic regulator for our earth.
Monday, December 14, 2009
GREEN HOUSE EFFECT A BOON OR A CURSE?!
The term “GREEN HOUSE EFFECT" is used for mentioning warming influence of the atmosphere. Our atmosphere behave as a semi permiable membarane for particular radiation. The short wave radiation penetrates through the atmosphere almost unimpeded to the earth surface. Where as the long wave radiation reflected by the earth surface is blocked by the atmosphere, absorbed and converted into heat energy.
Before proceeding, Here I wish to mention "What is green house effect/" The glass roof of a closed car allows the light to enter in side where as it does not allow the heat inside to escape thus it does not allow the heat inside to escape thus it keeps inside warmer.
With out the green house effect our earth may be frozen and the earth temperature may fall down to -18 C to -20C. Do you know the average temperature of earth is 15C. The earth atmosphere acts as a permanent trap. In the atmosphere there are many numbers of gases, Primarily Nitrogen and Oxygen, with traces of several other gases and water vapor in varying proportion. While Carbon dioxide, Methane, Nitrous oxide, Ozone, the so called green house gases are of 0.01 percent only in dry air.
The amount of green house effect gases varies due to natural causes such as volcanic activity but recently they have increased to a greater extent which is alarming now.
The root cause of this problem is clearance of tropical forest, rapid industrialization, burning of more petroleum fuels, natural gas, coal and other fossil fuels.
Since 19th century the emission of carbon dioxide the main green house effect gas has increased more than sixty times. Due to lack of forests this emitted carbon dioxide increased concentration in the atmosphere with the green house effect gases.