LIFE ON EARTH: 3.2 BILLION YEARS AGO:

Discussion in 'General Science & Technology' started by paddoboy, Feb 16, 2015.

  1. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    Well, have we found life on other planets and compare what elements are needed?
     
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  3. cosmictraveler Be kind to yourself always. Valued Senior Member

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    Not as yet that I know about.
     
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  5. Fraggle Rocker Staff Member

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    We are many years away from even traveling to planets with the right gravity and chemistry that might support life. And considering how long the voyage would be and how long it will even take the radio waves they send back to reach Earth, it's very unlikely that even the youngest among us will be around to learn about what they discovered.
     
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  7. paddoboy Valued Senior Member

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    Speaking interstellar of course.
    With some luck, the right political outlook and good economic times, we could do it in a couple of decades, to Mars at least.
    I think I may just see that out!
     
  8. Fraggle Rocker Staff Member

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    We've already explored enough of Mars to be fairly certain that it does not support life, although it may have done so a couple of billion years ago when it was warmer and wetter. Perhaps a few ancient lifeforms were just barely able to adapt to the slow transition to today's barren, virtually airless conditions.

    Of course, the problem that nobody talks about when enthusiastically hoping to find life on another planet: It might be so different from life on Earth, perhaps not even carbon-based, that we won't even recognize it when we see it.

    It's human hubris to assume that life everywhere in the universe has the same general properties as life on Earth.
     
  9. paddoboy Valued Senior Member

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    Most likely correct, but just perhaps, we just have not dug deep enough as yet.
    Can't really argue with that.


    Agreed.
    I envisage life throughout the Universe, to be at many scales of evolutionary advancement, including levels of intelligence comparable with our own and even in advance of that, separated only by the tyranny of time and distance.

    I sincerely hope that Seth Shostak's prediction of finding evidence for life within the next 20 years is realized....Well at least before I kick the bucket!
     
  10. Fraggle Rocker Staff Member

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    With today's technology, we cannot possibly land a probe (or put it orbit) on one of the exoplanets that have been identified as reasonable places to hope for life (gravity, temperature, elements, atmosphere, rotation rate, polar angle, orbital stability, etc.) within a mere 20 years.

    Kepler 22-B is the closest planet in its sun's habitable zone that we have found. And it is six hundred light years away! So it will take at least 600 years to get there. And, of course, another 600 years for the probe to send back the message telling us that it found a civilization with post-industrial technology.

    So you and I will probably not be around to hear the joyful news.

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  11. Beer w/Straw Transcendental Ignorance! Valued Senior Member

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    Well I do believe Voyager is dead but hooray anyway.
     
  12. paddoboy Valued Senior Member

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    I am sure Seth was inferring detection of electromagnetic signals of sorts being detected, and/or some form of primitive life within our own solar system.
    I'll do some checking though.
     
  13. Fraggle Rocker Staff Member

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    Very unlikely. In an enormous universe with more than one quintillion stars, it's reasonable to expect that our star is not the only one with a life-bearing planet.

    But if you're just looking at our solar system, the probability of life on Mars or Venus is extremely low, and on the other planets we might as well round the probability figure to zero.

    Life is a local reversal of entropy, so the places to look for it are where the environment could reasonably support a local reversal of entropy.
     
  14. paddoboy Valued Senior Member

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    With the additional fact of the ingredients for life being everywhere we look, I would totally agree with that sentiment.
    Certainly a logical assumption to make.

    I agree in actual fact. We have far better chances of detecting life within our solar system, on some of the moons, like Europa and Enceledus.
     
  15. Fraggle Rocker Staff Member

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    That's a long shot. Too cold, and in most cases, not enough gravity.

    If life has actually sprung up on one of those satellites, it would likely not be anything at all like Earth life. The odds are good that humans who eventually land there would not even recognize it as alive.

    For starters, whatever it is wouldn't be moving fast enough to catch anybody's eye.

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  16. paddoboy Valued Senior Member

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    I see it as our best shot with regards to our solar system....probably pretty basic, but life.
     
  17. Trippy ALEA IACTA EST Staff Member

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    To be fair - geothermal vents. It might be more recognizable than you're expecting...
     
  18. brucep Valued Senior Member

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    I think based on our criteria for being alive we won't have problem recognizing what's alive. Especially if it's trying to eat us. Some analysis may be required but we'll figure that part out.
     
  19. brucep Valued Senior Member

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    Europa Gravity is ~ .1345_earth gravity. Kinda like Barsoom but with way more lift potential.
     
  20. Fraggle Rocker Staff Member

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    The chemistry of an organism in such an exceptionally different environment is likely to be so different from ours that it wouldn't be able to eat one of us any more than vice versa.

    Not to mention, our "criteria for being alive" are based entirely on our observations of terrestrial life. Homeostasis and cellular structure, in particular, don't seem like deal-breakers, yet they are probably the two criteria that would be most visible, and therefore the ones we'd be most likely to look for.
     
  21. jabbaska Registered Member

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  22. dumbest man on earth Real Eyes Realize Real Lies Valued Senior Member

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  23. jabbaska Registered Member

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