Have aliens visited earth?

[jason_t]

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murchinson meteorite

chiral proteins

CO2 cycle on mars. indicates life

Posted a million times.

http://www.space.com/scienceastronom...fe_050216.html

Not going to explain more. DOne it million times.

Oh, jason_t = full of [censored].

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Hi, we're talking about complex, intelligent life here. Good luck.

[wacki]

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Hi, we're talking about complex, intelligent life here. Good luck.

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Hi, universe is gigantor and we've likely got life on 2 planets in this solar system and some people think more.

[wacki]

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There are probably 100,000,000,000 galaxies, each containing an average of 100,000,000,000 stars. Yet a cathedral with three grains of sand in it is more densely packed than the universe.

I'll let others do the math.

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* For 1,000,000 civilizations in the galaxy
o the average distance between them will be ~ 150 ly!!!
o two-way communication will take at least 300 years!
* If the lifetime of a technical civilization is less than 3000 years
o Average distance is so large that civilizations will die, on average, before two-way communications can be established!

http://instruct1.cit.cornell.edu/cou...o101/lec35.htm

[tonypaladino]

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Hi, universe is gigantor

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Gigaaaaaannnnttoooooorrrrrr

[jason_t]

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[ QUOTE ]
Hi, we're talking about complex, intelligent life here. Good luck.

[/ QUOTE ]

Hi, universe is gigantor and we've likely got life on 2 planets in this solar system and some people think more.

[/ QUOTE ]

Hi, and evolution needs to happen just so for complex life forms to develop. It's a parlay, and a pretty crazy one.

[Leaky Eye]

For all we know it could always happen given the right conditions.

[jason_t]

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For all we know it could always happen given the right conditions.

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Evolution is random.

[TimM]

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For all we know it could always happen given the right conditions.

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Evolution is random.

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Mutations are random, yes, but if you do something randomly for a long enough time, you eventually cover a lot of the possibilities.

[jason_t]

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
For all we know it could always happen given the right conditions.

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Evolution is random.

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Mutations are random, yes, but if you do something randomly for a long enough time, you eventually cover a lot of the possibilities.

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Not when the search space is as large as it is. There is an insane number of DNA combinations. Most of them are junk. Hitting upon ones that lead to complex life is rare.

[Leaky Eye]

Evolution is not random, it is precisely guided by the environment. Mutation is what is random.