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I've been wondering

  1. Jun 11, 2006 #1
    This is my first post(Oh, second post. =P) here. I usually lurk the boards because I feel I don't know enough about the topics here to discuss anything.

    This one thing has been bothering me.

    I've read before that when we obverse things in space we are not seeing them as they are now, but as they were in the past.

    So, say we observe a random galaxy that is 1.5 million light years away. We are seeing it 1.5 million years in the past, right? So if we were to go to that galaxy, it would look nothing like as we were observing it from Earth? Wouldn't it be possible that life could have evolved in that galaxy? We wouldn't be able tell since we're observing it in the past.

    I'm not entirely sure if I'm perceiving this correctly or not. If someone could explain it to me I'd appreciate it alot.
     
  2. jcsd
  3. Jun 11, 2006 #2

    Janus

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    As far as the galaxy itself goes, generally, they don't change very fast, so We really wouldn't notice much change, especially at the level of detail we can attain at that distance. Speaking of which, at that distance, we would not be able to detect life anyway, so we don't know if that galaxy even had life 1.5 million years ago, given the images we now have.

    But yes, some changes could occur that would not be aware of for 1.5 million years. For example there could be a supernova in that galaxy today and we would have to wait 1.5 million years before we saw it.
     
  4. Jun 11, 2006 #3
    Thank you for answering, Janus.

    I find it very interesting that 1.5 million years is really nothing to a galaxy. And that we would have to wait 1.5 million years to know if something even did happen in the galaxy. O_O
     
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