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Community shelf Community shelf -> BRINGING OUT THE BEST IN U........ -> Go to message
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It is very nice.
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Is it true that there could be intelligent life out there?


Despite the huge number of sightings, abductions and government sponsored cover-ups that have allegedly taken place over the years, there is no proof that alien life exists. But this doesn’t stop researchers looking.

Searching for aliens


The Search for Extra-Terrestrial Intelligence (SETI) is based at the University of California in Berkley and has several radio telescopes that are dedicated to listening out for signals from alternative life forms. The researchers need to be dedicated since despite constant searching after picking up a promising signal in 1977, they haven’t heard anything else.
But SETI isn’t just waiting for intelligent aliens to contact us. In 1974, they beamed their own signal out into space from the Arecibo telescope in Puerto Rico. The signal is a binary radio message which, when displayed as a rectangle of squares and spaces, makes up a picture of a human, our position in the solar system and even the structure of our DNA.
The signal was aimed towards the imaginatively titled M13 area of the universe, which is a huge cluster of stars 25,000 light years away. The thinking was that such a large number of stars had a high chance of harbouring a planet with intelligent life. However, we still have another 24,966 years to wait before the signal reaches the area.

Intelligent life in the Milky Way


But could there be intelligent life sharing the Milky Way with us? Consider the number of stars like our Sun in the Milky Way, then take the fraction of stars which have planets orbiting them, then take the fraction of planets with a suitable environment for life to evolve, then take the fraction of those planets where life has evolved, then take the fraction where life on those planets is intelligent. Finally, take the fraction of intelligent life that is capable of communication, and then take the mean lifetime of that life form. There is a fair bit of guesswork involved in predicting some of these variables, but the outcome is thought to be an estimated 72 civilisations in the Milky Way which are able to communicate. This calculation is called the Drake Equation first written down by Frank Drake who is now the Director of SETI.
But even with so many possible intelligent life forms capable of communication out there, the distances involved mean that it’s likely they would be at least 200 light years away. This means that a conversation with even the chattiest of aliens would involve waiting 400 years for a reply to the simplest question. It would be the ultimate long distance relationship!

Catalogs Discussion Forums -> Mechanics -> Gravity -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]

Hello,


       I read in a book that the formula   is not applicable to calculate 'g' inside the earth's surface.


       Is it true.


      If yes then why.

Catalogs Discussion Forums -> Counselling Zone -> Preparation for iit jee from 9th standard -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]

Hello,i want to know about the preparation for iit jee from 9th standard.


I am going to TIME coaching classes in coimbatore.


Which books can i refer other than my school books(ncert/cbse).


Also please suggest how to overcome the problem of low concentration-span.


Your answer will be very valuable for me.Thank you

Community shelf Community shelf -> Astronomy -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
The light years are below the star name.
Community shelf Community shelf -> Astronomy -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
The columns are as follows:
stars,colour,temperature in degree celcius,mass in terms of solar mass,power in suns,radius in terms of solar radii,distance in light years.
Community shelf Community shelf -> Astronomy -> Go to message
This Post 0 points    (Olaaa!! Perrrfect answer.   in 0 votes )   [?]
i posted the article in a different pattern but after it got posted all the columns got mixed. sorry
Community shelf Community shelf -> Astronomy -> Go to message
This Post 5 points    (Olaaa!! Perrrfect answer.   in 1 votes )   [?]


Table G2a

 
Star Comparison Chart

Star      Color      Temperature in      Mass in terms   Power in   Radius in terms      Distance in

                           degrees Celsius     of solar mass    Suns          of Solar Radii          Light Years

Sun       Yellow           5,700                    1                      1                 1                          8 light min.

Proxima

Centauri    Red               2,300                  0.1                Unknown       Unknown                         4

Barnard’s

Star          Red               3,000                  0.1                    0.01              0.2                               6

Epsilon

Eridani     Orange           4,600                   0.1                     0.4               0.8                              11

Alpha

Centauri   Yellow             6,000                    1                        2                1.4                               4

Altair        White              8,000                   3                        12                 2                               17

Vega        White              9,900                   3                         61               3.3                              25

Sirius       White              10,000                  3                        27                2                                8.6

Rigel        White              10,000                  3                       52,000           92                              777

Regulus   White               11,000                  8                       221               4.3                              78

Hadar       Blue                 25,500                 20                      79,000           24                           526

Alnilam     Blue                 27,000                 20                      112,000         44                          1,360

 
 
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