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Thread: black holes and light

  1. #1 black holes and light 
    Forum Professor wallaby's Avatar
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    i need some clarification on the escape velocity of light from a black hole.

    as i am told light escaping a black hole would not have enough energy to escape the black holes gravitational field when it is beyond the Event Horrizon. since light trying to escape the black hole would only be travelling along a curved path leading toward the singularity that would mean that space beyond the horizon is bent back on itself wouldn't it?

    i'm really confused.. :?


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  3. #2  
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    Dear Dr. wallaby:
    Everything about black holes is as confusing as controversial. Avoiding the tentatively supernatural, assuredly hypothetical issue is probly the best way to deal with black holes?


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  4. #3  
    Forum Isotope Zelos's Avatar
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    the black hole have normal bent space, but extremly bent, outside the event horizont. inside the horizont the spacetime is completly ripped apart,if u imagen it like u have a rubber plane that representing spacetime. then we have 1 kind of balls, bakks that bend this rubber plane (have mass) others that dont (no mass, photons). if u place a ball heavy enough so the bending becomes impossible for the no-mass ball to escape you have a blackhole, and the event horizon is like u have cut of a part from the rubber plane where.
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  5. #4  
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    To think that a black hole's gravitational pull could sucked down individual particles of light is just stunning.
    “If our Gods and our hopes are nothing but scientific phenomena, then let us admit it must be said that our love is scientific as well.”
    -quotation from Mathias Villiers de L’Isle-Adam’s Tomorrow’s Even (1986)
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  6. #5 Re: black holes and light 
    Forum Senior Imaplanck.'s Avatar
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    Quote Originally Posted by wallaby
    i need some clarification on the escape velocity of light from a black hole.

    as i am told light escaping a black hole would not have enough energy to escape the black holes gravitational field when it is beyond the Event Horrizon. since light trying to escape the black hole would only be travelling along a curved path leading toward the singularity that would mean that space beyond the horizon is bent back on itself wouldn't it?

    i'm really confused.. :?
    Thats an excellent description of why light can't escape a blackhole, how come you are confused?
    "A man's ethical behavior should be based effectually on sympathy, education, and social ties; no religious basis is necessary. Man would indeeded be in a poor way if he had to be restrained by fear of punishment and hope of reward after death." Albert Einstein
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  7. #6 Re: black holes and light 
    Forum Professor wallaby's Avatar
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    Quote Originally Posted by Imaplanck.
    Quote Originally Posted by wallaby
    i need some clarification on the escape velocity of light from a black hole.

    as i am told light escaping a black hole would not have enough energy to escape the black holes gravitational field when it is beyond the Event Horrizon. since light trying to escape the black hole would only be travelling along a curved path leading toward the singularity that would mean that space beyond the horizon is bent back on itself wouldn't it?

    i'm really confused.. :?
    Thats an excellent discription of why light can't escape a blackhole, how come you are confused?
    it was just one of those days.
    back when my views of what spacetime was were somewhat different.
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  8. #7 Re: black holes and light 
    Forum Senior Imaplanck.'s Avatar
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    Quote Originally Posted by wallaby
    Quote Originally Posted by Imaplanck.
    Quote Originally Posted by wallaby
    i need some clarification on the escape velocity of light from a black hole.

    as i am told light escaping a black hole would not have enough energy to escape the black holes gravitational field when it is beyond the Event Horrizon. since light trying to escape the black hole would only be travelling along a curved path leading toward the singularity that would mean that space beyond the horizon is bent back on itself wouldn't it?

    i'm really confused.. :?
    Thats an excellent discription of why light can't escape a blackhole, how come you are confused?
    it was just one of those days.
    back when my views of what spacetime was were somewhat different.
    Ah, I thought it was posted yesters or today or something.
    "A man's ethical behavior should be based effectually on sympathy, education, and social ties; no religious basis is necessary. Man would indeeded be in a poor way if he had to be restrained by fear of punishment and hope of reward after death." Albert Einstein
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  9. #8 Re: black holes and light 
    Forum Radioactive Isotope mitchellmckain's Avatar
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    Quote Originally Posted by wallaby
    i need some clarification on the escape velocity of light from a black hole.

    since light trying to escape the black hole would only be travelling along a curved path leading toward the singularity that would mean that space beyond the horizon is bent back on itself wouldn't it?
    Yes that is a fair but technically incomplete statement. You have to remember that space and time are not separate. It is space-time which is bent (curved) and so what your statement is missing is the fact that only the future portion of space time is "bent back on itself". The general relativist represent this as little two sided cones (one side representing past and one side representing future). So inside the event horizon the cones are bent so that the future cone is pointed towards the black hole which means that all possible paths that any object can travel inside the event horizon will bring it closer to the singularity.

    Quote Originally Posted by wallaby
    ias i am told light escaping a black hole would not have enough energy to escape the black holes gravitational field when it is beyond the Event Horrizon.
    Now this is not really accurate. First of all I don't think the path that light follows near a gravitational object depends on the energy of the light. Second we already concluded above, that all possible paths inside the event horizon lead toward the singularity, so what does the energy of the light have to do with whether it can escape the black hole?
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  10. #9  
    Forum Senior Imaplanck.'s Avatar
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    yea yeah yeah we all know gravity is to degree that time stops on the surface of a black hole. We all know that the escape velocity is beyond that of even light. Thats as fancy as you need to go.
    I fell asleep in between what you just said, but its far too much superbly.
    "A man's ethical behavior should be based effectually on sympathy, education, and social ties; no religious basis is necessary. Man would indeeded be in a poor way if he had to be restrained by fear of punishment and hope of reward after death." Albert Einstein
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  11. #10 Re: black holes and light 
    Forum Professor wallaby's Avatar
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    Quote Originally Posted by mitchellmckain
    so what does the energy of the light have to do with whether it can escape the black hole?
    nothing
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  12. #11  
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    :? it does... but it is a constant..
    Growing up, i marveled at star-trek's science, and ignored the perfect society. Now, i try to ignore their science, and marvel at the society.

    Imagine, being able to create matter out of thin air, and not coming up with using drones for boarding hostile ships. Or using drones to defend your own ship. Heck, using drones to block energy attacks, counterattack or for surveillance. Unless, of course, they are nano-machines in your blood, which is a billion times more complex..
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  13. #12  
    Forum Isotope Zelos's Avatar
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    planck radiation can escape a blackhole, in about 10^100 years will there only be low frequent radiation in the entire universe, if it havent gone big crush before, or a new big bang
    I am zelos. Destroyer of planets, exterminator of life, conquerer of worlds. I have come to rule this uiniverse. And there is nothing u pathetic biengs can do to stop me

    On the eighth day Zelos said: 'Let there be darkness,' and the light was never again seen.

    The king of posting
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  14. #13  
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    :? are there things like "little bang's"?? sounds more and more reasonable to me at the moment...

    serious... why 1 BIG bang, if you don't really need all the mass in the universe to create a huge explosion..
    Growing up, i marveled at star-trek's science, and ignored the perfect society. Now, i try to ignore their science, and marvel at the society.

    Imagine, being able to create matter out of thin air, and not coming up with using drones for boarding hostile ships. Or using drones to defend your own ship. Heck, using drones to block energy attacks, counterattack or for surveillance. Unless, of course, they are nano-machines in your blood, which is a billion times more complex..
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  15. #14  
    Forum Isotope Zelos's Avatar
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    some scientist think that if you press amtter to planck density you get a small bigbang where new matter/energy is created
    I am zelos. Destroyer of planets, exterminator of life, conquerer of worlds. I have come to rule this uiniverse. And there is nothing u pathetic biengs can do to stop me

    On the eighth day Zelos said: 'Let there be darkness,' and the light was never again seen.

    The king of posting
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