Any aliens out there?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by John J. Bannan, Jun 27, 2007.

  1. kaneda Actual Cynic Registered Senior Member

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    Laika. The point is that this is a stable orbit. Something can fly around a black hole at maniac speed and neither fall in nor fly out from the orbit.
     
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  3. orcot Valued Senior Member

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    true for anything that circles above the event horizon.

    Small quistion on black holes: the original star must have rotated right and the only thing preventing the star of collapsing was the outwards pressure from the fussion reaction inside (therefore if this ends the star collapses).
    But while the star shrinks momentum is kept so shouldn't their be a point inside the event horizon where the cetrifugal forces prevent the star from collapsing any further?
     
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  5. kaneda Actual Cynic Registered Senior Member

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    orcot. Yes, if you see the way we have advanced in only 100 years, things will proceed at an ever faster rate (I think more things have been invented since 1950 than all the years before 1950) so a society 100 years in advance of ours would have many incredible things beyond our present understanding.
     
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  7. Laika Space Bitch Registered Senior Member

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    Kaneda, I don't see your point at all. You have described an orbit. The tangential velocity necessary to maintain a circular orbit depends on the mass of the body you're orbiting and the distance at which you orbit it. For a circular orbit around the Earth (low Earth orbit), you need to be moving at around 8 km/s. For a circular orbit around a black hole of 1 Earth mass (with the same orbital radius), you still need to be moving at around 8 km/s. It's that simple.
     
  8. kaneda Actual Cynic Registered Senior Member

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    orcot. All large/dense objects in space spin. A black hole requires an escape velocity of beyond light speed. Since a neutron star which is neutrons can have an escape velocity of 2/3 light speed, then the contents of a black hole are beyond that stage (possibly quarks and electrons?) As all such things do, it would spin.
     
  9. kaneda Actual Cynic Registered Senior Member

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    Laika. We have five solar masses here and something orbiting them just 100 miles away in a stable orbit. I would have thought that something could not be naturally caught at such a distance and have just the right fraction of light speed to stay where it was rather than being pulled into the black hole.
     
    Last edited: Nov 18, 2007
  10. kaneda Actual Cynic Registered Senior Member

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    Duplicate post
     
    Last edited: Nov 18, 2007
  11. orcot Valued Senior Member

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    Recently the've discovered that a planet that most probable was in orbit INSIDE it's parent star when it was in it's red giants fase, Basicly the planet survived because it was far denser then it's suns outer layer.
    So it is possible however a 100 miles :bugeye: I think I'l have to ask for a source and I'm pretty sure your miles are going to turn into AU's
     
  12. kaneda Actual Cynic Registered Senior Member

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    The outer part of a red giant can be virtually a vacuum by our standards so a planet could survive that though there would be some drag on it for the time that the star was that size.


    http://www.sciencedaily.com/releases/2006/01/060111075045.htm


    Spinning Black Hole Leaves Dent In Space-time

    Homan's team -- which includes Jon Miller of the University of Michigan, Rudy Wijnands of Amsterdam University and Walter Lewin of MIT -- observed a region less than 100 miles from the event horizon of a black hole system called GRO J1655-40. Here, matter can orbit a black hole relatively stably, but occasionally it wobbles at certain precise frequencies. This is a direct result of how the black hole deforms space and time, a four-dimensional concept that Einstein called space-time.
     
  13. orcot Valued Senior Member

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    wow less then a 100 miles black holes are weird
     
  14. blobrana Registered Senior Member

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    "Researchers using NASA's twin Mars rovers are sorting out two possible origins for one of Spirit's most important discoveries, while also getting Spirit to a favourable spot for surviving the next Martian winter.
    The puzzle is what produced a patch of nearly pure silica -- the main ingredient of window glass -- that Spirit found last May. It could have come from either a hot-spring environment or an environment called a fumaroles, in which acidic steam rises through cracks. On Earth, both of these types of settings teem with microbial life.
    "

    Read more

    http://en.wikipedia.org/wiki/Rhynie_chert
    http://en.wikipedia.org/wiki/Yellowstone_National_Park
     
  15. blobrana Registered Senior Member

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    "Signs of life on Mars may be hiding under its rocks, or perhaps hiding inside those rocks. A new study offers a simplified technique for detecting biological and pre-biotic molecules that become trapped inside minerals.
    Studying seven samples of the mineral jarosite collected from various places on Earth, a group of researchers was able to identify amino acids, the basic components of proteins, that had presumably been incorporated into the mineral's crystal structure. "

    Read more
     
  16. OilIsMastery Banned Banned

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    3,288
    Vitalists and biogenic hydrocarbon "theorists" think the entire universe and the entire periodic table is alive so no shock here. I'm skeptical.
     
  17. DaleyPaley Registered Member

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    Yeah, I doubt they will find life on Mars. Europa maaaayyybbbbeeeee, but not mars. Although I hope they do.
     
  18. Enmos Staff Member

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    43,184
    You are an idiot.
    Why are you still spouting this nonsense anyway ? Need to convince yourself of something ?
     

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