How to silence a room full of physicists

Discussion in 'Physics & Math' started by jmpet, May 3, 2009.

  1. jmpet Valued Senior Member

    Messages:
    1,891
    If black holes are true black bodies and absorb absolutely everything, and if there are black holes in the centers of galaxies, then how do you account for the direction the local cluster is headed- towards "The Great Attractor"? Do you mean to tell me that black holes move through space? How is that possible if they're black holes? Do you mean it's possible to "push and move" a black hole? Please explain-

    Oh yeah- I speak ENGLISH, not math. So throwing an equasion at me will not satisfy me- I need it explained in WORDS.
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. temur man of no words Registered Senior Member

    Messages:
    1,330
    Do you mean to tell me that black holes do not move through space? Why do you think it is not possible? Do you mean it's impossible to "push and move" a black hole? Please explain-
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. jmpet Valued Senior Member

    Messages:
    1,891
    I mean exactly that- it is not possible to push or move a black hole- it's a black hole after all...
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. temur man of no words Registered Senior Member

    Messages:
    1,330
    Pulling a rabbit out of a hat will not satisfy me- I need it explained.
     
  8. jmpet Valued Senior Member

    Messages:
    1,891
    The Milky Way is headed towards this thing:

    "The Great Attractor is a gravity anomaly in intergalactic space within the range of the Centaurus Supercluster that reveals the existence of a localised concentration of mass equivalent to tens of thousands of Milky Ways, observable by its effect on the motion of galaxies and their associated clusters over a region hundreds of millions of light years across.

    "These galaxies are all redshifted, in accordance with the Hubble Flow, indicating that they are receding relative to us and to each other, but the variations in their redshift are sufficient to reveal the existence of the anomaly. The variations in their redshifts are known as peculiar velocities, and cover a range from about +700 km/s to -700 km/s, depending on the angular deviation from the direction to the Great Attractor.

    http://en.wikipedia.org/wiki/The_great_attractor

    Does this mean the black hole in the center of the galaxy is also moving?
     
  9. temur man of no words Registered Senior Member

    Messages:
    1,330
    I was asking the reason why you think they should not move.
     
  10. jmpet Valued Senior Member

    Messages:
    1,891
    So you're saying black holes are not completly black?
     
  11. temur man of no words Registered Senior Member

    Messages:
    1,330
    So you're saying completly black things cannot move?
     
  12. geistkiesel Valued Senior Member

    Messages:
    2,471
    The consensus is that black holes are extremely dense remains of a star [or some other stellar object] that has collapsed onto itself. The BH total mass before and after collapse does not affect motion, or the gravitational attraction from other masses.

    Your description of the Great Attractor is consistent with descriptions I am familiar with. It seems a tad strange to utilize the Big Bang Theory - rapid expansion uniformly in all direction - yet end up, like the present, with formations:shrug: of the Greta walls and the vast void of space separating the Walls. Big Bangers usually avoid these kinds of embarrassing discussions.
    reading the literature one discovers anything but a universal agreement. Hawking proposed a few years back that there is a statitical possibility that light within an event horizon of a BH can exceed the speed of light and hence, excape the dreary the event confinement to the BH proper.

    In a similar vein, electrons, for example, passing near the event horizon may undergo a transformation whereby an electron gets ripped/zapped into a positron, the process of which results in the emission of light, lots of light, ergo the black hole ain't a block hole, it is very highly visible, or it should be if the BH is as advertised. Most Black Holers are merely repeating rote passages learned somewhere, could it have been in school?


    I am only repeating what I have read.

    An answer, or explanation that has never been forthcoming to me, in rational terms, is, what visible data exists showing unambiguous evidence, a photograph would work for me, of a BH?

    I would cvaution you on the extent of bluntness in your thread - do as I say here, and not as I do - this advice is free, and you didn't even have to ask for it.
     
  13. Exterminate!!! Registered Member

    Messages:
    254
    possible that the mass gravity displacement of a black hole can pull smaller black hole's towards them?

    It's just a condensed star. some are more dense, i'd guess.

    :fright:
     
  14. Syzygys As a mother, I am telling you Valued Senior Member

    Messages:
    12,671

    Yes.

    There is nothing in the definition of blackness that it can not or shouldn't move.

    Please Register or Log in to view the hidden image!

     
  15. Nasor Valued Senior Member

    Messages:
    6,231
    Of course it is possible to move a black hole. Set a black hole next to a star, and the star's gravity will pull the black hole toward it. Throw an object into a black hole at a high speed, and the black hole will absorb the momentum of the object and begin drifting in the direction the object was heading.
     
  16. jmpet Valued Senior Member

    Messages:
    1,891
    Thanks for your post.

    As to the other posters, I will have to remember that if I am in a spaceship falling towards a black hole to fire my photon torpedoes and move the black hole out of my path.
     
  17. Nasor Valued Senior Member

    Messages:
    6,231
    That might be hard, since you'll probably be trying to move something with the mass of a star. Your photon torpedoes will impart some non-zero movement on it, but it will be very close to zero.
     
  18. jmpet Valued Senior Member

    Messages:
    1,891
    What kind of energy would it take to (further?) accelerate a SMBH to say, 1 million miles an hour?
     
  19. Nasor Valued Senior Member

    Messages:
    6,231
    Look up the mass of a star, and plug the speed you want into the kinetic energy equation. I'm guessive the answer will be "a whole whole lot". Why does it matter?
     
  20. jmpet Valued Senior Member

    Messages:
    1,891
    It matters because my fundamental understanding of black holes tells me that throwing waves (of any sort) at it won't make it move.
     
  21. Nasor Valued Senior Member

    Messages:
    6,231
    Your fundamental understanding is wrong. Block holes obey the laws of conservation of momentum, gravity, etc. just like any other object. If you place a black hole near another star of equal mass, they will both fall toward each other.
     
  22. Pandaemoni Valued Senior Member

    Messages:
    3,634
    Black Holes are collapsed stars. If the star was moving when it collapsed, the black hole will likely be moving in more or less the same direction. Moreover, black holes *can* be moved. First, they can have an electric charge, and can therefore respond to other charges. More practically, black holes have mass and move in response to gravity, just like any other mass. (In fact most stellar black holes orbit the galactic center just like the stars that made them do.)

    If you have two black holes of equal mass, it is entirely possible for they to fall into orbit of one another. If you have a huge gravitational effect, like the Great Attractor, it is entirely possible that black holes will fall toward it. Why? Because the great attractor has a lot of black holes itself, and is more massive than any single galaxy.

    If you raised this question in a room full of physicists, and if they fell silent, I'd be surprised.
     
  23. James R Just this guy, you know? Staff Member

    Messages:
    39,397
    jmpet:

    Suppose our Sun was magically replaced by a black hole of equal mass. If that happened, the Earth's orbit would not be affected at all - it would be attracted towards the hole in exactly the same way that it is currently attracted to the Sun.

    Also, the hole would keep orbiting the centre of the Milky Way in the same orbit that the Sun now has. Nothing about the nature of black hole prevents it from being acted on by gravity in the same way that a star is acted upon.
     

Share This Page