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Life on Earth, forever?

  1. Jan 28, 2012 #1
    "Life on Earth, forever?" Well obviously NOT, that looks more like a fairytale.

    When is the time when 1000 humans have left and have/not returned to the surface, according to the current trend?

    And, if we consider development, and emerging of new Space-countries, what will be the answer for the same?
     
  2. jcsd
  3. Jan 28, 2012 #2

    DaveC426913

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    Gold Member

    Your thoughts are disjointed and terse. I had to read your post three times to understand it.

    What does this mean?

    Well, seeing as our current tally is zero, there is no trend as yet.


    Same.
     
  4. Jan 30, 2012 #3
    No reason why we should leave in toto. Why do you think humans are leaving Earth forever?
     
  5. Jan 30, 2012 #4
    When the Sun ages and inflates towards 'Red Giant' phase would be a good time to vacate planet. Okay, there's several billion years to go, and there'd be several millenia warning-- Our distant descendants could probably wait for Mercury to be engulfed before starting to react...

    By then, I'd hope there were several functional 'beanstalks', if theory advances haven't given us 'antigravity'...
     
  6. Jan 30, 2012 #5
    And humans wouldn't even be humans anymore.
     
  7. Jan 30, 2012 #6
    There is another scenario that might develop that involves the earch assuming an orbit farther from the sun than it is now due to the decrease in solar gravity. Consideration of this possibility is based on observation of what is assumed occured with a planet, V391 pegasi b orbiting a star such as our own which went through the red giant stage and is now a white dwarf.



     
  8. Jan 31, 2012 #7
    Exactly. If we somehow manage not to destroy ourselves, there is no telling how "humans" will look like in a 1000 of years, let alone in millions or billions of years. Even if we went back to stone age tomorrow, and forgot about genetic engineering etc. in two, three million years we would look completely different.
    As for OP question, I think it is not unimaginable that the life on Earth will last "forever" (forever i.e. untill the planet is destroyed). And by life I mean "a life" not human life. There is currently no known threat (short of gamma ray burst maybe?) that could completely sterilize the earth. Even full on nuclear exchange could not kill all the bacteria in earth, ocean, atmosphere. There are deep caves and hot volcanoes that host life, that can be safely regarded as independent of human affairs.
     
  9. Jan 31, 2012 #8
    Gamma rays could do it, also a sufficient sized meteor/comet impact could physically break the planet up which would probably kill almost everything - although I grant some extremophiles may survive in ice/rock even though this may be unlikely.
     
  10. Jan 31, 2012 #9

    What makes you think that humans will undergo such a drastic transformation in a mere thousand years? As we go back in time thousands of years we find that ancient Egyptians Babylonians, Sumerians were as human as we are. Please consider the Egyptian, and other human mummified remains as well as skeletal remains that go back several or more thousand years.

    Chinchorro mummies
    http://en.wikipedia.org/wiki/Chinchorro_mummies

    About the OPED.

    If indeed mankind were to find its home threateneed by a bloating sun at that advanced time it's hard to imagine that it would lack the technological resources to respond effectively in order to protect itself or its home. it would have plenty of time to prepare. Some have suggested a purposeful nudging of earth into a higher orbit in order to compensate for the sun's bloating. A placement of an asteroid or asteroids in orbit about the earth has been suggested as a way to gradually accomplish this.
     
    Last edited: Jan 31, 2012
  11. Jan 31, 2012 #10

    Ryan_m_b

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    The sun increasing in size is a process that will occur over hundreds of millions of years. Hypothesising about what a possible sentient species on Earth could do at such time is rather pointless.
     
  12. Jan 31, 2012 #11
    ^ Transhumanism

    There will be some form of biological activity on the planet until it is a whirl of atoms in the sun.
     
  13. Jan 31, 2012 #12
    I realize that, but think about genetic engineering. In a hundred years or so you will probably be able to choose hair, eye and skin color of your child (or even yourself). And the standard for beauty changes very quickly, think what was considered beautiful 50 and 300 years ago. I think in a 1000 years time people could look like weirdos for us without even trying.
     
  14. Jan 31, 2012 #13
    The problem is this: choices for hair colour/eye colour etc are already active genomes. So we can chop/change them all we like. I doubt there would be any major evolutionary change to any complex species in a mere thousand years (lets say 50 generations with everyone having children at 20.)

    50 generations will not do much biologically, even if we are actively making genetic decisions.

    Please see: http://en.wikipedia.org/wiki/Timeline_of_evolution for an idea of the timescales involved.
     
  15. Jan 31, 2012 #14
    Heh, I really know what timescales are involved, I have recently read two books on evolution. But it is not the only force at work. Evolutionary changes in 1000 years will be minuscule, sure, but I was talking about artificial changes dictated by cultural changes, which (compared to evolution) are very fast. Today you can only change existing active genomes, but who says what will be possible in 50-100 years? I don't want to post more OT posts, I just felt you had an impression I don't know what evolution is, while I do. I had to correct you, it's important, you are a person on the Internet ;)
     
  16. Jan 31, 2012 #15
    The problem is this - lets say that in 50-100 years people start actively modifying DNA, the program would need to be extensive to have any impact on the human races evolution as a whole - think of the costs involved and also that socio-economically it is the poorer countries with the larger populations. My point is that any genetic modifications are a small drop in the ocean of humanity.

    I do understand what you are putting forward, I just think the timescales you have outlined are extremely unrealistic as they are too short - IMO.

    Always good to have a discussion. :smile:
     
  17. Jan 31, 2012 #16
    These far-future scenarioes and the ways in which mankind might respond to them are being discussed by scientists on a regular basis. Exactly where along the time continuum, in your personal opinion, will such discussions cease to be pointless?
     
  18. Jan 31, 2012 #17
    I thought you were referring to evolutionary changes.
    Thanks for the feedback.
     
  19. Feb 1, 2012 #18
    Nicely put Radrook. There is a physics point to this sort of discussion IMO, in that defining the likely life-span of Observers in cosmological terms tells us something about our present situation. Similarly discussions about the apparent "Cosmological Coincidence" that the mass-energy density and lambda/Dark-Energy are observed to be similar in size. In both "early" and "late" cosmological epochs this isn't necessarily so, which poses the conundrum as to why we observe the current near-unity of their ratio.

    According to work by Greg Laughlin, Fred Adams and Peter Bodenheimer, stars should continue shining in the Galaxy at roughly the same observed level for the next ~trillion years. Low-mass stars, as they go off the Main Sequence, brighten significantly and experience a period of luminosity comparable to the Sun for ~5 billion years, enough time for Observers to evolve around any planets at ~Earth-like distances. As red-dwarfs are the most common stars in the Galaxy, then why don't we observe ourselves on one during its late-life blossoming? Why are we still in the "early days" of stellar evolution in orbit around a relatively high-mass star?

    These are all valid questions, leading to fertile investigations in astrophysical processes, as evidence by the papers by Laughlin, Adams & Bodenheimer, for example. Late-time "speculation" is like any other astrophysical gedankenexperimenten and thus well worthwhile.
     
  20. Feb 1, 2012 #19

    Ryan_m_b

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    Staff: Mentor

    I'm not sure I have an answer to that, whilst it's amusing to discuss presupposing whether or not humans will even exist in hundreds of millions of years and then asking what they might do at that point really doesn't make much sense. We could ask "what could we conceive of now if we had to deal with the issue now" but that is different to "what will we do in hundreds of millions of years."
     
  21. Feb 1, 2012 #20
    We differ in our definition of what constitutes the meaning of the word "senseless" in relation to discussions. So I guess we will simply have to agree to disagree on that point.
     
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