Future Cosmology:

Discussion in 'Astronomy, Exobiology, & Cosmology' started by paddoboy, Feb 7, 2017.

  1. paddoboy Valued Senior Member

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    In the far far distant future, a few hundred billion years hence, we will certainly have passed our "use by date" as will the Earth and the Sun. Our local group of galaxies will have merged into one big conglomeration of stars that are left and that have further evolved, distant galaxies will have receded beyond our view, the CMBR will be probably undetectable.
    All that will exist as far as any evolved being around any appropriate star will be concerned, is there own large galaxy, in a continuing evolving, expanding spacetime.

    So with the current knowledge that we possess of an expanding universe and the evidence for that [the CMBR and galactic recession] virtually nullified, what will such a civilisation presume?
    Will they descend into further ignorance and chaos as they lack the tell tail signs that have enlightened present day astronomy/cosmology.
    Is there any possible optimism that can be gained knowing now what is ahead?
     
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  3. Michael 345 Valued Senior Member

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    Best we make a Blue Ray DVD to leave them

    Title

    ' This is what it looked like and where you come from '

    Sorry bout that

    Take care ya'all

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  5. paddoboy Valued Senior Member

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    Yeah but perhaps they may be just another result of abiogenisis that happens many hundreds of years after the Sun's "use by date" with no connection to us at all.

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    They will not have distant galaxies to see any recession and cosmological redshift, and the CMBR will be probably non existent by then.
    I'm trying to be as optimistic as possible, but they aren't really going to have much to go on.
     
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  7. dumbest man on earth Real Eyes Realize Real Lies Valued Senior Member

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    ...seems somewhat similar to your Thread started on December 12, 2013 :
    "The static universe:
    In a few trillion years or so, when the expansion of the Universe, has reached a stage where all distant galaxies have disappeared beyond our observable horizon, and our local group/cluster/wall of galaxies has merged into one huge conglomeration of stars, and the CMBR has all but disappeared, what will be our view, or the view of any intelligent species be of the Universe around us?

    Let's also surmise that all of the scientific observations and models of today have been lost during all those eons, so that we or any other Intelligent species, is not able to stand on the shoulders of the giants that have gone before them.........Would we, or could we assume that our Universe was static??

    What evidence would we have to show otherwise?"

    ...hmmmm...
     
  8. Michael 345 Valued Senior Member

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    So now your telling me they might not be linked to us?

    OK I can live with that

    So when they find the Blue Ray (assuming we make one) do you think they will see it as
    • evidence of UFOs?
    • evidence they did descend from us
    • evidence we were gods and begin to worship us?
    I go for the god option so we can look down on them from our clouds, smile at each other and say they got it right
     
  9. paddoboy Valued Senior Member

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    Well the Sun has only 5 billion years left and even if we have populated other systems, which I'm sure we will have, what remnants of us will be left? ....and if we are talking a few hundred billion years hence when distant galaxies have moved beyond our observable horizon, and of course the CMBR will be probably imeasurable......

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    I mean I am trying to remain as optimistic as possible...

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  10. Michael 345 Valued Senior Member

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    Only the aforementioned Blue Ray

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    If you had a chance to live on another planet what would you like the new planet to be like?

    Leaving out the apple pie stuff like world peace
     
  11. paddoboy Valued Senior Member

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    Challenging.......I'm an old sea dog at heart, so I would love extending expanses of water to sail/exlpore.......

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    see.......
    http://www.sciforums.com/threads/best-things-i-have-ever-done.144780/
     
  12. Write4U Valued Senior Member

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  13. Dinosaur Rational Skeptic Valued Senior Member

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    If intelligent observers exist in the far distant future, their cosmology will be similar to the cosmology when it was believed that our galaxy was the only one in existence. This assumes an absence of historical records describing a universe similar to what we now observe.
     
  14. Russ_Watters Not a Trump supporter... Valued Senior Member

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    A good start will be that they will know roughly how old the universe is and therefore that it is very far along in its evolution.

    Also note that the expansion and therefore rough evolution of the universe was a mathematical prediction of General Relativity. It is nice that we have such good evidence for the BBT, but a lot could still have been figured out with predictions based on the math. E.G., the CMB was a predicted at roughly the same time as it was accidentally found. So while the confirmation is nice, we figured it out before observing it.
     
  15. paddoboy Valued Senior Member

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    How will they actually no this? The CMBR will probably be undetectable, and in the range of 0.00001K or similar.
    OK, that makes plenty of sense......
    Thanks.
    Just shows actually what a powerful theory GR is and always will be.
     
  16. Russ_Watters Not a Trump supporter... Valued Senior Member

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    5,051
    From the mixture of elements in the "current" stars you can tell roughly how many supernovas their materials have been through.
    http://www.physlink.com/education/askexperts/ae465.cfm

    However, I'm dubious that a universe as old as the one you suggest could contain much life. It's pretty easy to form a star out of a nebula that is 100% hydrogen, but not so easy to form one when there is a lot of other materials in it. As a result, the rate of star formation is dropping rapidly and the vast majority of stars that will ever form already have.
    https://www.quora.com/In-terms-of-s...he-vast-majority-of-stars-that-will-ever-form
     
  17. dumbest man on earth Real Eyes Realize Real Lies Valued Senior Member

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    There is some interesting reading at the Link you Posted, Russ_Watters.
    - all of the below quoted from : David Kahana, physicist unhinged at this Link : https://www.quora.com/In-terms-of-s...he-vast-majority-of-stars-that-will-ever-form (emphasis - dmoe)
    "So while our sun is expected to live about 10 billion years, before it ends up as a carbon-oxygen white dwarf of somewhat uncertain mass, a star of mass 0.08M may live from 20-200 trillion years: possibly even longer - the long term evolution of such very low mass stars is not really well known. It is believed that low mass stars <0.25M remain fully convective throughout the majority of their lifetimes, so that they therefore burn almost all of their initial hydrogen to helium, before finally developing a radiative core, and then ending up as helium white dwarfs. The convection prevents the buildup of any chemical concentration gradient in the star and so very much extends its lifetime."
    ... "The lifetime of stars also depends pretty significantly on the metallicity, which is increasing in the interstellar gas with time - higher metallicity stars live longer, up to some maximum metallicity, because higher metallicity makes a star less luminous for a given mass, due to the greater opacity of elements heavier than helium. The sun has a metallicity of about 0.02, which is quite typical of the Milky Way galaxy. The maximum lifetime is not achieved until probably a metallicity of 0.04 or so.

    After the point in time when the average metallicity of the gas reaches that value, the average lifetimes of newly formed stars will begin to drop again. Asymptotically the mass distribution in the interstellar gas is expected to approach 20% hydrogen, 60% helium, and 20% metals. This is expected to happen at a time of about one trillion years. After that time, stars will still form but they will not live nearly as long."
    ... "But gas is recycled into the interstellar medium by supernovae and by mass loss from older stars, and mass loss is very poorly understood in general. It is also probable that the rate of star formation falls more rapidly than linearly with the mass of the remaining gas.

    Taking account of these effects it is probable that ordinary star formation ends for an isolated spiral galaxy at a time that is on the order of 1–100 trillion years, which is about the same time as the very low mass dwarf stars come to the end of their lives.

    Under all of these assumptions, that τR is on the order of the age of the universe, that the mass of gas in the galactic disk is rather small in comparison to the mass of the whole galaxy, and that the Milky Way is estimated to contain between 200 and 400 billion stars right now, I would certainly conclude that the vast majority of star formation that ever will take place in the history of our galaxy has already happened. Our galaxy is probably not too atypical for a grand design spiral."
    - by David Kahana, physicist unhinged
    - all of the ^above^ quoted from, and much more at : https://www.quora.com/In-terms-of-s...he-vast-majority-of-stars-that-will-ever-form (emphasis - dmoe)
    A future of Trillions or even 200 Trillions of years is far beyond the "...a few hundred billion years hence", posited in the OP.
     
    Last edited: Feb 11, 2017

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