Our fate

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Avatar, Feb 12, 2005.

  1. Avatar smoking revolver Valued Senior Member

    Messages:
    19,083
    It's been known for some time now that Milky Way and Andromeda are heading towards each other and since about year 2000 a.d. it is known that it will occur in about five billion years - the Milky Way and Andromeda may collide. A new galaxy may form. Actually it's invevitable. The two black holes attracted by each other's gravity will merge. The course is set.
    If life or humanity will still exist at that time in the future our solar system has two possibilities.
    1. If Andromeda hits our galaxy from another side of it, we being as far away from it as possible, it is possible that our star system will be catapulted into intergalactic space.
    2. If we are close enough to the collision the radiation, gamma rays from the two black holes going quasar will instantly destroy any atmosphere any of our star system planet has or will have. The planets will toast.
    So it seems that even if we leave our star system in search of a safe place, then that safe place can not possibly be in our own galaxy. And of course not in Andromeda galaxy.
    It seems that even if we calculate at which place we will be at the exact time of the two galaxies colliding, our fate is to leave our Milky Way galaxy. By natural means or not.
    I won't go into sci-fi of humanity leaving our galaxy on intergalactical star ships, but my question for space scientists here - how will it effect the stability of our own star system if we're thrown out of our galaxy at an increasing speed?

    p.s. I have another question that may require a new thread, but alas.. -> what happens to the initial black hole when it is swallowed by another black hole?
    Do the singularities merge? Can it be observed from inside the singularity?
     
    Last edited: Feb 12, 2005
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. Ophiolite Valued Senior Member

    Messages:
    9,232
    It's closer to 3 billion than 5... Either way life on Earth will have become untenable before then, in around 1 to 1.5 billion years, because of increased solar temperature.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Avatar smoking revolver Valued Senior Member

    Messages:
    19,083
    There has been a recalculation for the collision? I didn't know of it. Can you please give a source? I don't doubt your words, I'm just eager to read more about it.

    Yes, it is true about the Earth, but not about our star system as a whole.
    As you see I haven't mentioned our specific planet anywhere.
    The habitable zone then will be further away from the centre of it (our system).
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. Lucas Registered Senior Member

    Messages:
    447
    I'm pondering the possibility that the result of the collision of the two galaxies will be an elliptical galaxy. Actually, the thought is that elliptical galaxies form exclusively due to mergers of galaxies, but not all mergers of galaxies generate an elliptical galaxy (e.g. our galaxy has experimented at least one merger in the past and is not elliptical)
     
  8. Avatar smoking revolver Valued Senior Member

    Messages:
    19,083
    Here is one supercomputer simulation of the merge -> http://www.haydenplanetarium.org/hp/vo/ava/movies/G0601andmilwy.mpeg

    source
     
  9. geistkiesel Valued Senior Member

    Messages:
    2,471
    The cross section for collisions of colliding galaxies is such that few, if any, actual collisions will occur. As the masses attract each other, if they attract each oher, there will be few if any measurable trajectory perturbations. There will be few if any two body black-hole conditions that can be considered in isolation, such that one need only consider the attracting fields of the two stellar objects under scrutiny.

    Assume that two identical black holes (as of this moment black holes have not been unambiguously identified) are moving toward each other on a common line. Each BH is 10x the volume of our sun, or bigger. When the force of attraction of each becomes amplified and the velocity near the speed of light, what do you think will happen?
    I say the universe around the collision point will be a very dusty place with a lot of expended small sized blast material moving hither and yon.

    Your words that our solar sustem will be cast into integalactic space are not supported with any scientific reasoning or experimental data. You must first determine the gravitational effect of multiple collisions, or trajectory perturbations separated by huge distances and unambiguously answer the questions of just what gravity physically is. Newton's force equations tells us nothing of the underlying physics and dynamics of gravity. You are a long way from telling us a another story of our final doom that contains any rational content. You write fiction, and then not even science fiction.

    Geistkiesel
     
  10. Avatar smoking revolver Valued Senior Member

    Messages:
    19,083
    As for our solar system being cast into intergalctic space, that is not an idea by me and you are wrong to say that it is not suported by any scientific reasoning.
    The theory is that by Prof. John Dubinski (University of Toronto) and he has done computer calculations and simulations of the event. I heard of this possibility from him in a BBC Horizon series film about Supermassive Black Holes.

    Besides I didn't say that it will be cast, I said that it may be cast. No simulation as of yet is 100% precise.
     
    Last edited: Feb 12, 2005
  11. Avatar smoking revolver Valued Senior Member

    Messages:
    19,083
  12. Maddad Time is a Weighty Problem Registered Senior Member

    Messages:
    251
    In five billion years the Sun will swell so much that it will engulf Mercury, Venus, and Earth. It's radiation will go up 2,000 times, stripping the envelopes from the gas giants and leaving only their rocky cores behind. Pluto will be hotter than Earth is now. Being made mostly of ices, it will evaporate.

    Ophiolite is correct, including the rest of the solar system as a whole.
     
  13. geistkiesel Valued Senior Member

    Messages:
    2,471
    Avatar, I didn't read the Dubinski paper but I did scan the headings thatincluded dark matter which is purley theoretical at the present time and has not been obserfved directly. Ferom this we maysay at a minimum he Dubinski thesis i pure speculation.

    I can only report a computer analysis by an aeronautical engneer at Univ. Texas. His program shows the motion of objects in gravity free zone when perturbed. He expanded his model to show the trajectories of three stellar bodies located aribitrarilly wrt each other. When the objects got close enough for gravitaional effects to operate a consistent result always occured. Two of the objects always were trasformed into orbits around each other, the third object mrely passed by the two orbitng objects in a sling shot trajectory. There were no collisions.
    School of Auronautical Engineering, UT , Austin , Yexas NAme forgotten
    Geistkiesel
     
  14. Avatar smoking revolver Valued Senior Member

    Messages:
    19,083
    Maddat: If so, that doesn't change the fact that in 5 (or 3) billion years, we will be safer in another galaxy.
     
  15. Avatar smoking revolver Valued Senior Member

    Messages:
    19,083
    geistkiesel: Does that apply to any gravity the objects ummm hold? These are galaxies with supermassive black holes at their centre, that's pretty extreme.
    And even if the galaxies won't merge it's possible the black holes go quasar and us being at the outer reaches of our own galaxy can be gamma toasted (depends where Andromeda will pass if it doesn't merge).

    p.s. I'm not a doomsday fanboy, the universe is life and death, nothing wrong with it.

    So you are saying that the galaxies won't collide although one has less mass and thus its' gravitational pull is weaker than that of ours (we being the prime pullers).
    Ok that is your claim and I register it next to mine.

    p.p.s. About dark matter, we haven't seen it, but we know it's there somewhere. Of course it's well possible that it isn't distributed inside galaxies. I agree with that weakness in Dubinski's model. Maybe he should have one without dark matter.
     
  16. Avatar smoking revolver Valued Senior Member

    Messages:
    19,083
    !!!p.s. I just remembered (doh) that even if our galaxies don't merge (Andromeda+MW) there are pretty much other that have (telescope data). Our own galaxy has merged with a small other galaxy in the past. (or so do astronomers tell).
    So that's entirely possible.
     
  17. Avatar smoking revolver Valued Senior Member

    Messages:
    19,083
  18. Maddad Time is a Weighty Problem Registered Senior Member

    Messages:
    251
    How can you be safer when you will not be here?
     
  19. Avatar smoking revolver Valued Senior Member

    Messages:
    19,083
    As long as I know the first steerable aircraft of this civilization was invented in 1911. Measely 60 years later people of this civilization stepped on the moon of their planet. Given 1 billion years of development I see no problems for us to be potentially able to go to other star systems @ reasonable speeds or even leave our galaxy.

    And I didn't say "I", I said "we", we - the mankind.
     
  20. weed_eater_guy It ain't broke, don't fix it! Registered Senior Member

    Messages:
    1,516
    From what I've read on various sites, in a few hundred years, interplanetary travel will be commonplace, ventures to other stars will take place. In many thousands of years, we may have intergalactic capability, assuming we manage to stay alive and technologically innovative, likely with the population of humans that would be in existence. Where the hell will we be if we survive to a million years? Let alone a billion. Other universes? Building universes? I think the galaxies colliding will be the least of our interests. The end of the universe may even be cheatable at that point.
     
  21. Avatar smoking revolver Valued Senior Member

    Messages:
    19,083
    Restaurant at the end of the Universe

    Please Register or Log in to view the hidden image!


    /laughs and hints/
     
  22. Maddad Time is a Weighty Problem Registered Senior Member

    Messages:
    251
    Species last a million to ten millon years. You, or we, will not have to worry about anything a billion years from now. We won't be here.
     
  23. Avatar smoking revolver Valued Senior Member

    Messages:
    19,083
    None other species before (at least to our knowledge) have had the ability to change their DNA. We have the ability, we can cheat (the speed of) evolution.
     

Share This Page