Where is dark matter?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by wet1, Dec 19, 2001.

  1. wet1 Wanderer Registered Senior Member

    Messages:
    8,616

    Please Register or Log in to view the hidden image!



    Finding Dark Matter
    Credit & Copyright: A. J. Benson (Caltech) et al., U. Durham, PPARC
    Where is dark matter? Galaxies rotate and move in clusters as if a tremendous amount of unseen matter is present. But does dark matter exist in the greater universe too -- and if so, where? The answer can be found by comparing the distribution of galaxies observed with numerical simulations. This comparison became much more accurate recently when over 100,000 galaxy observations from the 2-Degree Field Galactic Redshift Survey were used. In the above frame from a computer simulation of our universe, a 300 million light-year slice shows dark matter in gray and galaxies as colored circles. The red box indicates the location of a rich cluster of galaxies, while the green box shows a more typical cross-section of our universe. Analyses indicate that the immense gravity of the pervasive dark matter pulls normal matter to it, so that light matter and dark matter actually cluster together.
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. Rigelsir00 Registered Member

    Messages:
    66
    WET, COULD YOU TELL ME WHY WHITE DWARF ARE CANDIDATE FOR THE I MISTERIOUS DARK MATTER?ALSO BROWN DWARF?
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. (Q) Encephaloid Martini Valued Senior Member

    Messages:
    20,855
    TEDMAN

    THERE IS A PROBLEM WITH YOUR KEYBOARD! THE CAPS LOCK KEY IS STUCK!

    oops, so was mine, but it's fixed now.

    Please Register or Log in to view the hidden image!

     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. wet1 Wanderer Registered Senior Member

    Messages:
    8,616
    Tedman,

    First, typing with the cap lock on is the equivalent of shouting. Some will be annoyed at that and you will find mention of it with ever increasing frequency.

    White dwarfs and brown dwarfs are final stages in stars' life. When they run out of the needed energy to continue to use their internal fuel, they then die. At the end is a cold dark mass. An unseen mass. There are many that postulate that these "dead stars" make up a goodly portion of the mass we don't see. The only way I know that they can be found is to look for the gravity they possess influencing another body or mass or the off chance of catching them occulting another luminous body.
     
  8. Rigelsir00 Registered Member

    Messages:
    66
    THANK YOU.
     
  9. KneD Le Penseur Registered Senior Member

    Messages:
    206
    Well, in fact, white and brown dwarfs arent candidates for dark matter, they ARE dark matter....
    We know they exist, and we know they must be important for the total mass of galaxies.

    But, brown dwarfs aren't candidates for the dark matter in the spaces between galaxies, they can't exist there.
    Also, brown dwarfs probably aren't the only dark matter in a galaxie, then they should be very numerous.

    So, brown dwarfs are dark matter, but there must be other dark matter too......
     
  10. wet1 Wanderer Registered Senior Member

    Messages:
    8,616
    KneD,

    I think that your english is improving quite a bit from when you first came here. Your replies are very understandable.


    You are indeed correct.
     
  11. Rigelsir00 Registered Member

    Messages:
    66
    WAIT A SECOND I DIDNT UNDERSTAND

    Please Register or Log in to view the hidden image!

    THE BROWN BWARF ARE DARK MATTER ,BUT THEN WHY DID YOU SAY THAT THEY ARE NOT AND THEY CANNOT EXIST?
     
  12. wet1 Wanderer Registered Senior Member

    Messages:
    8,616
    I think that you may have misunderstood. What KneD referred to is that these items could not be found "between" galaxies as they are bound by gravational force to the galaxy they are in. So they exist in the galaxies but not outside them except in unusal circumstances.

    We are not certain what dark matter is. Those stars that are burned out are matter we can not normally see, hence they are dark matter. But other dark matter clusters with normal matter that we can see. That was what the map was of. Where we think the dark matter is by how it affects galaxies and how those galaxies cluster together.
     
  13. Rigelsir00 Registered Member

    Messages:
    66
    THANK YOU WET FOR EXPLAINING

    Please Register or Log in to view the hidden image!

     
  14. (Q) Encephaloid Martini Valued Senior Member

    Messages:
    20,855

Share This Page