Life can go on forever

Discussion in 'Human Science' started by kmguru, Jun 20, 2002.

  1. kmguru Staff Member

    Life can go on forever - An accelerating universe does not have to fry life.

    27 May 2002

    Life can carry on indefinitely. Physicists in the United States have come to the comforting conclusion that just because the universe is accelerating as it expands, this does not necessarily sound the death knell for life in the far future1, as some have claimed2.

    In the right kind of accelerating universe "life can go on indefinitely", say Katherine Freese of the University of Michigan and William Kinney of Columbia University in New York. We don't know whether ours is the right kind, so the doomsday scenario is still possible, but at least there's hope.

    An accelerating universe limits how much energy is available to life because distant regions get too far away to be reached by organisms confined to travelling below the speed of light.

    Faced with finite energy resources, organisms can use up energy more slowly by slowing down their metabolism. In principle there's no limit to how sluggish life can get, so it could eke out an existence indefinitely.

    But there's a snag. To have any sort of metabolism - to do anything, in other words - an organism has to get rid of heat.

    This can only happen if the organism is hotter than its surroundings, because heat can flow only from hot to cold. An organism that is cooler than its environment will eventually fry.

    There's a limit to how cool an accelerating universe can get. As life slows to conserve its limited energy supplies, it too will cool. Eventually, though, it will hit this temperature limit and stop being able to shed heat.

    Freese and Kinney now suggest that this lower temperature limit need not be fixed, but might itself decrease over time. It all depends on why the universe is accelerating.

    Constant worry

    One reason why a universe might expand is that empty space actually exerts a pressure that counteracts the force of gravity. This pressure is quantified by the so-called cosmological constant, inserted into Einstein's equations of relativity, which describe the structure of space and time.

    A universe with a cosmological constant acquires a background radiation. It is this warm vacuum that some believe will eventually fry ultra-sluggish life.

    Freese and Kinney reckon that two alternative explanations for the acceleration of the expanding universe - quintessence and cardassian expansion - give life a rosier prognosis.Maybe one day we'll figure out how to synthesize a new universe in a lab, set off a Big Bang, and move into it

    The quintessence model invokes a kind of vacuum energy like that produced by a cosmological constant. But crucially, this energy, and thus the background temperature, decreases with time. The same is true of cardassian expansion.

    This means that a life form could conceivably slow its metabolism down to avoid running out of energy, while keeping pace with the cooling universe so that it can always radiate heat into a cooler environment.

    Even if the universe does turn out to be dominated by a cosmological constant, Freese and Kinney are reluctant to give up hope. One day, they speculate, we might figure out how to synthesize a new universe in a laboratory, set off a Big Bang, and move into it, abandoning our present universe as a lost cause.

    Freese, K. & Kinney, W.H. The ultimate fate of life in an accelerating universe. Preprint.(2002).
    Krauss, L. M. & Starkman, G. D. Life, the universe, and nothing: life and death in an ever-expanding universe. Astrophysical Journal, 531, 22 - 30, (2000).

    © Nature News Service / Macmillan Magazines Ltd 2002
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  3. Xenu BBS Whore Registered Senior Member

    Why worry at all? The universe will do what it does and we can't stop it. If all life dies, it dies.
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  5. Xenu BBS Whore Registered Senior Member

    To me this just shows how moronic humanity is. Always trying to control. Always trying to "win". Against what? Nature will always "dominate" in the end.
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  7. Adam §Þ@ç€ MØnk€¥ Registered Senior Member

    Xenu, the universe is my bitch, remember? We humans have throughout our evolution overcome nature to survive. I see no reason for that trend to cease.
  8. kmguru Staff Member


    And you are a part of it....

    We are part of "nature"....dude...

    So, we shall dominate......
  9. Xenu BBS Whore Registered Senior Member

    Yes my words are a bit strong. I'm a little emotional and irrational this morning. Which is alright.

    Yes humanity has an inner strive for survival. In order to survive, we have manipulated and controlled our environment. Now I ask is it truly manipulation and control of nature or are we actually working with nature and in concordance with nature? Scientific laws are representations of natural laws, are they not? Same situation, two outlooks.

    I think what I was fuming about above isn't so much how "humanity tries to control", but more of the attitude of such. The statement "the universe is my bitch" falls into that attitude. Humanity (not all, mostly Western countries), I feel, needs to be a bit more humble and learn its place. Not above nature. Not below nature. Not side-by-side with nature. But within nature.
  10. kmguru Staff Member

    I would go with that...

    Now....blackholes... anyone....

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  11. Xenu BBS Whore Registered Senior Member

    I'm wondering how it would be possible to make our own big bang to create a new universe. You need energy to create energy right? Energy is constant right? I'm not too up on quantum theory.

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