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Looking further and further into the past?

  1. Jul 23, 2012 #1
    I understand how looking at the night sky is, essentially, peering into the past, as the photons that hit your eye have been traveling for years and years. I read that telescopes, as they progressively strengthen, give us the ability to look even further into the past. This is what confuses me.

    Telescopes can see further, but aren't they still observing the photons that are hitting the lens at the current moment?

    Hold up! I may have answered my question while thinking about it. The age of the photons (and how far into the past you're looking) is dependent upon the distance they've traveled. The further the object that the photon originated from, the longer the photon must travel to reach us and the "older" it is.

    So the telescopes are still observing the photons that are hitting their lenses, it's just as they get more powerful, the objects they are viewing get further away, resulting in our ability to look even further into the past?

    I apologize that this thread is essentially my train of thought regarding the issue. I would really appreciate any insight and guidance towards the answer.

    Thanks in advance!
  2. jcsd
  3. Jul 23, 2012 #2


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    Hello Powder Mtn,
    welcome. You seem to have answered your question. So think of a new question or something you want to learn about.
  4. Jul 23, 2012 #3


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    Except that large telescopes use mirrors rather than lenses, spot on.
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