Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Galaxies drifting apart

  1. Apr 23, 2010 #1
    If the galaxies are drifting farther apart at close to light speed then why are we bothering to try to go to other galaxies?
  2. jcsd
  3. Apr 23, 2010 #2


    User Avatar
    Science Advisor
    Homework Helper

    Where do you get the idea that we are trying to go to other galaxies?
  4. Apr 23, 2010 #3
    We are having enough problems just going to places in our solar system.
    we have no workable way to even attempt a trip to the nearest neighboring star system.
    Even in Star Trek they pretty much stay in the same galaxy.
    The distances involved between galaxies foils even the sci-fi writers methods of travel for the most part.
  5. Apr 24, 2010 #4
    that's right, absolutely no chance of travelling between galaxies.
    Your statement is wrong. galaxies are moving away from each other. The speed of motion depends on their distance from each other. For every Million lightyears between two galaxies they are moving, relative to each other, at about 20km per second.
    This is because the space between them is expanding.
  6. Apr 24, 2010 #5


    User Avatar
    Homework Helper

    That really depends on how close the galaxies are to each other. For example the galaxies in our local group are not receding, because gravity is strong enough to keep things together against the expansion. In fact our closest neighbour, Andromeda, is coming right at us. It is only on very large scales that gravity can't keep galaxies together anymore.
  7. Apr 25, 2010 #6
    While what you say is true the distances involved are still so great the we have no concept of what it would take to get from our galaxy to Andromeda. Even if we could travel at .999C it would take millenia to go between these galaxies.
  8. Apr 27, 2010 #7
    I believe it's more a matter of seeing other galaxies; and since what we view is light, if the distance is great enough some galaxies are moving away from us/we are separating at a rate that is actually faster than the speed of light. (Which is more boggling than thinking about time dilation.)

    So given our late appearance to this party, there are some galaxies we will never see, as they were too far away when humans evolved, let alone now.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook