Black holes.

Discussion in 'Astronomy, Exobiology, & Cosmology' started by john smith, Sep 28, 2005.

  1. john smith Tongue in cheek Registered Senior Member

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    Anyone out there know anything about black holes??Although i studied physics and the like for 5 years, i still never really had an adequate answer,so ould anyone tell me "what the hell is a black hole?"
    Any answers will be gratefully recieved.

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  3. Boris2 Valued Senior Member

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  5. kenworth dude...**** it,lets go bowling Registered Senior Member

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    a tear in space-time.maybe.its one of those things like,what is an electron?which i only have a vague hand wavy idea about.
     
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  7. may_wentee Registered Senior Member

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    Best advice I can give you is to take the 'A' train to M-87.

    May_wentee

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  8. KitNyx Registered Senior Member

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    Funny thing that post by Kenworth. It has actually been postulated that electrons are...micro-blackholes! Electrons have EXACTLY the same properties that would be expected except we have no theory as to how black holes of that size could avoid evaporating or decaying depending on the theory you subscribe to in mere moments...and elecrons, they last...well, we have yet to see one decay.

    - KitNyx
     
  9. Pete It's not rocket surgery Registered Senior Member

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    But why would all electrons have the same charge?
    And what would that make positrons?
    And how could electrons participate in nuclear interactions without absorbing the other reactants? (eg proton-electron-proton reaction)?
     
  10. Gattaca Registered Senior Member

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    It's a corpse of a dead star. A vampire with an endless ( not really) throat called "worm hole". And I truly don't know what the hell is it either. But I know if I ask the same question, I'd rather use Google and library.
     
  11. RoyLennigan Registered Senior Member

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    black holes are predicted to form when a star of reasonable size and near the end of its life span (usually a neutron star) collapses in on itself. all the mass of the star gets compacted into a relatively tiny area, eventually creating an event horizon in which the escape velocity (velocity at which something must acheive to counteract the gravitational force) exceeds the speed of light. nothing can escape its pull except through quantum tunnelling. many galaxies, including the milky way, are suspected to contain a supermassive black hole in the center.
     
  12. The Jabberwocky! Registered Member

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    Does anyone know how long a black hole lasts for or does it have no end
     
  13. beesmn Registered Member

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    I have another theory about black holes. I think they might be the vacuous wakes of the initial matter that exploded from the big bang. Since there was no matter in empty space at the time, there was nothing to slow the acceleration of the energy/matter that flew away from the center. If that is the case, that energy/matter is still accelerating and has long since gone past the speed of light (thus the blackness). Any energy/matter that draws sufficiently near the trail of this wake, can be sucked into it and accelerated, in some cases, still beyond the speed of light. This energy/matter would appear to be sucked into a black hole much the same as as it would if a body of sufficient mass would attract, hold it, and prevent light from leaving its sphere of influence.
     
  14. RoyLennigan Registered Senior Member

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    using the equations that stephen hawking created to explain the radiation that black holes emit, the time it takes for a black hole to 'evaporate' can be determined. though it would be virtually impossible to determine how long it would take for an existing black hole to disappear (no accurate information for the data needed), one can use a hypothetical instance to get an idea.

    in an otherwise empty universe, it would take a black hole of one solar mass 10 to the 67th power years to evaporate, a lot longer than our universe has been around. but it would take only 3 billion years for a black hole of 10 to the 11th power kg to evaporate.
     
  15. may_wentee Registered Senior Member

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    Good information. That means I may be around to see at least one Black Hole evaporation event in my life time.

    May_wentee :bugeye:
     
  16. c7ityi_ Registered Senior Member

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    is there yet evidence of black holes... like pictures?

    is a "black hole" like a neutron star... just that it's very tiny?
     
  17. RoyLennigan Registered Senior Member

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    since there cant be pictures of black holes (they emit no light) there is no direct evidence in that sense. but black holes perturb light such that it is accurately predicted. pictures of these perturbations have been taken, proving the existance of black holes. any light that is around or behind a black hole, relative to us, would be displaced by the event horizon, causing a ring of blackness, surrounded by a ring of dense light.

    a black hole usually forms after a neutron star has collapsed in on itself. usually, this happens immediately after a supernova. the mass is compacted until it reaches its Schwarzschild radius, a radius relative to the star's original mass. once it reaches this size, it becomes a black hole. the Schwarzschild radius of the sun is about 3 kilometers. the Schwarzschild radius of the earth is about 9 millimeters.
     
  18. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    I think it was Dirack who gave a very strange and interesting answer to this question: It runs something like this: consider high energy scattering events both in the future in which positrons are produced and one in the past past also. That positron could be an electron traveling "backwards in time" ("t" replaced by "-t" ) with charge + changed to - and this leaves all the equations unchanged.) - That is, one positron produced in the future scattering event could be an electron traveling backward into the past. There in the past it particiapated in the other ancient scattering event reverses again its direction of travel in time and changes charge, becoming a positron traveling into the future. It scatters again in the future, becoming a backwards in time traveling electron again etc. etc.

    A slice in time called "now" sees the same electron in many different places. No wonder all electrons are identical -there is only one. Why we don't see all the positrons is another question. Answer may be in some distant anti matter part of the universe an "anti-dyrack" is asking "why don't we see all the electrons?
     
  19. john smith Tongue in cheek Registered Senior Member

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    Thank you Roy, this was exactly what i was looking for, although i was wondering what actually happens/why does the star 'collapse in on itself' at the end of its 'life span'??
    Cheers to you all,
    John :m:
     
  20. john smith Tongue in cheek Registered Senior Member

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    Yer well, some of us are different, tell me, if you would rather use "Google and library", why the hell are you here!??
     
  21. Von Chav Gold chains & Stella!! Registered Senior Member

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    Why don't you do the same my cocaine dependent friend? It'd be quicker than asking all these people to do it for you. Here's the address (in case you have forgotten) www.google.com , then type what your looking for. (Again, to refresh your memory, the subject is on "black holes", I believe you started the thread - but you may have forgotten.) I take it you just like people to to work for you, and your obese sausage fingers may not be up to the task at hand. Or are you attempting "intellectual debate"? Don't make me laugh you obese poon.

    I guess 5 years physics did'nt teach you much? LOL. 5 years sounds more like a fooking degree? 5 years studying physics? Was it GCSE for 12 year olds then?

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  22. (Q) Encephaloid Martini Valued Senior Member

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    why does the star 'collapse in on itself' at the end of its 'life span'??

    Gravity overcomes the outward pressure of the fusion process.
     
  23. may_wentee Registered Senior Member

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    5 years studying Physics and the like???

    May_wentee

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