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Some black holes may be older than time

  • 31-07-2012 10:04pm
    #1
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,537 Mod ✭✭✭✭


    http://www.abc.net.au/science/articles/2011/05/06/3207889.htm
    According to their work published on the pre-press website arXiv.org, some black holes could be remnants of a previous universe that collapsed in a big crunch and was then reborn in the big bang - 13.7 billion years ago.


Comments

  • Banned (with Prison Access) Posts: 3,455 ✭✭✭krd


    Well their idea depends on the BigBand/BigCrunch cycle theory. Which may not be true. And if it is true, it's hard to argue that time begins at the moment of the Big Bang.

    Primordial black holes are the black holes from the early universe. Some should still be around a be quite large. Other ones will have evaporated away to nothing. There are lots of different theories around black holes. There may be no small primordials left - they may shrink to a certain size where they can no longer maintain their gravity and explode.

    Saying that at the big crunch the laws change and are not understood, which may allow some black holes to escape the crunch is highly speculative - moon made of cheese speculative.


  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,537 Mod ✭✭✭✭Capt'n Midnight


    krd wrote: »
    Saying that at the big crunch the laws change and are not understood, which may allow some black holes to escape the crunch is highly speculative - moon made of cheese speculative.
    They've made a prediction.

    if it was possible to measure the age of a black hole - radiation / spin / whatever - then the prediction would be testable


  • Banned (with Prison Access) Posts: 3,455 ✭✭✭krd


    They've made a prediction.

    if it was possible to measure the age of a black hole - radiation / spin / whatever - then the prediction would be testable

    But first you have to find the primordial black holes first. No one has.

    Really big ones have been found - but smaller ones would be nearly impossible to see. Harder to see than rocks.

    Plus, I believe, the smaller they are, the faster they would evaporate through Hawking radiation, as the greater the ratio of surface area to volume.

    Then there are a couple of ideas of what happens when they get really small. One is that they get as small as a proton, and then grab an electron and become to all visible intents and purposes a pseudo-hydrogen. That idea has never been proved. But....it's an idea.

    Still, I wonder. If mini-black holes, can swallow neutrinos. All they would have to do to grow bigger again would be move into the path of a heavy neutrino flux - near a star or like it - and then they would grow big again. But I've never heard anyone mention neutrinos and black holes - so I'm not sure if there's just some reason they can't be swallowed.


  • Closed Accounts Posts: 5,064 ✭✭✭Gurgle


    Leave a bucket out in the rain until its full, thousands of individual raindrops fall in and form a single body of water.
    Now pour the contents from the top of a skyscraper, the water separates into drops and lands in a similar state to falling rain.

    Its possible that some of the drops that hit the ground contain the same molecules that were originally an individual raindrop. You could say the drop wasn't destroyed, it survived joining the water in the bucket and later separation from that body of water.

    But how could we tell if this happened?


  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,537 Mod ✭✭✭✭Capt'n Midnight


    Gurgle wrote: »
    Its possible that some of the drops that hit the ground contain the same molecules that were originally an individual raindrop. You could say the drop wasn't destroyed, it survived joining the water in the bucket and later separation from that body of water.

    But how could we tell if this happened?
    It's unlikely that a signature will ever be found.

    But if the original raindrop had a signature like Deuterium / Oxygen isotope ratios, if the drop nucleated around dust from the Sahara.


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  • Banned (with Prison Access) Posts: 3,455 ✭✭✭krd


    I think this is more interesting. Recent on Sixty Symbols
    http://www.youtube.com/watch?v=XE5PNbsUERE&list=UUvBqzzvUBLCs8Y7Axb-jZew&feature=player_detailpage

    One thing that's so interesting about black holes, is how speculative the subject is. The different theories vary hugely. The new one on Sixty Symbols, seems to rule out one of the horizons because of spooky action at a distance.

    Some theories are pretty wild - and probably pretty wrong (they can't all be right). Some theories the holes have a surface, in others they don't. In some beyond the event horizon is a dimensionless point - whereas in others there's and inner horizon (the inner horizon is kind of funky - it's where the light is trapped. A spinning black hole could allow for an inner shell - sphere - where centrifugal forces made gravity less than the speed of light.)

    But there are lots of theories. One I like is that when the hole evaporates to a certain point it explodes, releasing a tremendous amounts of energy. I thought these black holes might be good as weapons when we have to fight the alien wars - that is if we win the robot wars. But if the robots win the robot wars, they can use the black hole weapons against the aliens.

    What have raindrops to do with primordial black holes?


  • Closed Accounts Posts: 5,064 ✭✭✭Gurgle


    krd wrote: »
    What have raindrops to do with primordial black holes?
    Analogical context ;)


  • Banned (with Prison Access) Posts: 3,455 ✭✭✭krd


    Gurgle wrote: »
    Analogical context ;)

    You know what's really interesting about rain drops - they're perfect spheres as they fall (not like the classic teardrop shape everyone expect).

    But, bubbles in water, are some times spherical, but often and you can see this with you're own eyes, are heavily distorted as they rise.


  • Registered Users Posts: 4,290 ✭✭✭Tefral


    How does this fit in with Entophy and the theory of the heat death of the universe?

    I thought if there was another universe then there could be no black holes left from it as that universe would reach equilibrium?


  • Closed Accounts Posts: 5,064 ✭✭✭Gurgle


    cronin_j wrote: »
    How does this fit in with Entophy and the theory of the heat death of the universe?

    I thought if there was another universe then there could be no black holes left from it as that universe would reach equilibrium?

    It kinda fits around that theory.


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  • Registered Users Posts: 4,290 ✭✭✭Tefral


    Gurgle wrote: »
    It kinda fits around that theory.

    Thats what I thought... :o


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