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Movement of Galaxies in relation to each other

  1. Jun 12, 2009 #1
    hi folks, maybe somebody can help me with this:

    According to the standard theories of cosmology, the universe started with a "Big Bang" about 14 thousand million years ago and has been expanding ever since. Yet there is no centre to the expansion; it is the same everywhere. The Big Bang should not be visualised as an ordinary explosion. The universe is not expanding out from a centre into space; rather, the whole universe is expanding and it is doing so equally at all places, as far as we can tell.

    In 1929 Edwin Hubble announced that he had measured the speed of galaxies at different distances from us, and had discovered that the farther they were, the faster they were receding. This might suggest that we are at the centre of the expanding universe, but in fact if the universe is expanding uniformly according to Hubble's law, then it will appear to do so from any vantage point.

    As we know all matter in a galaxy is moving in rotation. But how is the movement of galaxies or even clusters of galaxies to each other? Is there any rotational movement between neighboring galaxies in addition to the expanding?
     
  2. jcsd
  3. Dec 1, 2010 #2
    Please, somebody can answer this question!!!!!!!!!!!!!!!!!!

    As we know all matter in a galaxy is moving in rotation. But how is the movement of galaxies or even clusters of galaxies to each other? Is there any rotational movement between neighboring galaxies in addition to the expanding?
     
  4. Dec 2, 2010 #3
    Although overall the galaxies are all moving away from each other - as Hubble's law says.
    They do have a local gravitational effect on each other, and nearby galaxies are sometimes moving toward each other.

    The milky way and a few other local galaxies are all moving in a particular direction - known as the great attractor.
     
  5. Dec 5, 2010 #4


    Our own Milky Way Galaxy has many satellite galaxies which orbit it.
    The closest is the Sagittarius Dwarf Galaxy. Prior to its discovery the most familiar ones were the Large and Small; Magellanic Clouds. Here is a list of Milky Way Satellite Galaxies. The ones with question marks are suspected of being satellites but not as yet fully confirmed.

    Excerpt:


    I Canis Major Dwarf .
    II Sagittarius Dwarf .
    III LMC .
    IV SMC .
    V Ursa Major II Dwarf .
    VI Ursa Minor Dwarf .
    VII Draco Dwarf .
    VIII Sculptor Dwarf Galaxy .
    IX Sextans Dwarf.
    X Carina Dwarf .
    XI Ursa Major I Dwarf .
    XII Fornax Dwarf .
    XIII Leo II .
    XIV Leo I .
    ? Leo IV.
    ? Boötes .
    ? Boötes II.
    ? Boötes III .
    ? Coma Berenices .
    ? Segue 2 0.07 35 dG D 2007
    ? Canes Venatici .
    ? Canes Venatici II .
    ? Hercules .
    ? Pisces II .
    .

    http://en.wikipedia.org/wiki/List_of_Milky_Way's_satellite_galaxies
     
  6. Dec 14, 2010 #5
    There IS movement but I've never read a summary/synopsis of such movement....likely it's rather random.

    Yes, in general. Our own Milky Way galaxy and the nearby Andromedia galaxy are moving toward a general rotatioonal "collision"....but few stars or planets will actually collide as all galaxies are 99% space....gravitational attraction will shift the orbits of most mass in both galaxies....
    I've seen computer simulations of galactic collisions but don't have any references...

    Here is one type of movement: http://en.wikipedia.org/wiki/Virgo-centric_flow

    and some discussion of collisions here:

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