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What is Black matter ?

  1. Aug 23, 2004 #1
    What is "Black matter"?

    I have heard somthing about "black matter" as an idea, but cannot find any information on it..
    Would anyone care to endulge me please?
    I am interested, for an odd reaon, I will specify later..

  2. jcsd
  3. Aug 24, 2004 #2
    I've never heard of "black" matter, perhaps you mean dark matter. Dark matter is a kind of matter theorized to make up over 90% of the mass in the universe. It was theorized for different reasons, for example...stars in our galaxy were noticed to revolve around the center faster than they should be, accoding to calculations of the gravitational force towards the center. When people saw that the calculated speed was slower than what was being observed, it lead them to believe that there was matter in the galaxy that we were not seeing or detecting. Although dark matter explains the illogic things that have happened, its still very hypothetical because it has not yet been detected. Dark matter is supposidly the reason for why the universe is accelerating in its expansion outward. Since gravity should be slowing it down, it made no sense for the universe to accelerate outward...it defied the laws of physics. Anyways, im gonna stop there because we probably arent even supposed to be talking about such theoretical things in this section of the forum. If you want to see threads about dark matter, just go to Theory Development, im sure you can find plenty there, or just do a search for "Dark Matter".
  4. Aug 24, 2004 #3
    Dark matter

    The Dark matter is something like a black hole, that we know its there but we don't know what actually is it, how is it. The idea of the dark matter is introduced when it was discovered that the linear velocity of the inner and the outer (visible) edge of a galaxy were very close to each other. It was explained that there is something present in the galaxy which is not visible (in any way) but very much massive then the ordinary things present in the galaxies and is extended to much far extent then the visible galaxy is supposed to be. Being located away from the center and much more massive it it causes the linear speed of the inner and the outer edge of galaxy to be close to each other. As we are unable to detect it, it is named as the Dark Matter.
    Last edited: Aug 24, 2004
  5. Aug 24, 2004 #4


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    Welcome to Physics Forums alexherhead!

    There are quite a few threads in General Astronomy & Cosmology discussing dark matter and dark energy, including some in the sticky - perhaps you could go and look there?
  6. Aug 24, 2004 #5
    re Black Matter

    Perhaps you mean a black body material? That is something that absorbs and reemmits radiation (IR usually where people talk about it) in all wavelenghts.
  7. Aug 24, 2004 #6
    Thanks, I am sorry I put this here..
    But I was curious..
    I was told NOT to go to the theory developement area, due to false facts..
    I placed this here, so I could get true or more reperatable statements..
    And thanks for the info and welcome..
  8. Aug 24, 2004 #7


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    There's nothing 'false' about dark matter! There are several different classes of observations pointing to its existence ... even 'dark energy' is quite fashionable in astronomy and cosmology these days. See you in GA&C!
  9. Aug 24, 2004 #8
    #1) I am sorry I used the word "reperatable", I am not sure why I did that..It was supposed to be Reputable.

    #2) I never said Dark Matter was NOT real, I said..
    #3) Thanks for welcoming me.
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