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How do measure and know about the vast scale of the Universe?

  1. Sep 16, 2011 #1
    To start, I'm not at all knowledgeable in physics; completely ignorant. Now, I know I could go ahead and research this on my own, but I've always felt like asking an actual interactive human being is the best way to gain direction compared to a lifeless search engine or book.

    So how do we know of the vastness of the macrocosm and microcosm alike?

    From a philosophical standing, this absolutely boggles my mind, and stimulates my spirit.

    Yes, I know because this is what we observe through our senses aided by instruments. But I would like just a little bit of direction to what I should research to thoroughly understand how we can come to perceive something so transcendent and beyond our self, from an integrated view that is both scientific and philosophical.

    EDIT: Image replaced with link to avoid stretching thread. Ryan_m_b
    http://www.kratosguide.com/wp-content/gallery/mind-pictures/earth-universe-comparison.jpg [Broken]


    How!? I want to know your perspective.
    Last edited by a moderator: May 5, 2017
  2. jcsd
  3. Sep 16, 2011 #2
    By recording previous peoples' efforts and building upon them we've come to our current viewpoint. Maybe correct, maybe not. Until we get a GUI no one knows for certain.

    What direction should I point you to find out more about how we've come to these ideas?

  4. Sep 16, 2011 #3
    As particle physics and cosmology have merged into each other you can easily get lost in the parts. So I would recommend a book that provides an overview of all the sciences in a way that is not only lucid, concise and clear, but also gives one a taste for the history of science as well.

    That book is Asimov's Guide to Science.
  5. Sep 17, 2011 #4


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    The observable universe is only about 10^44 the size of a proton.
  6. Sep 17, 2011 #5


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    I don't see what you mean by an integrated scientific and philosophical view. I'm also not sure of you're question, are you asking how science as discovered these things?
  7. Sep 17, 2011 #6
    More videos to blow your mind :)

  8. Oct 4, 2011 #7
    A lot of this question comes down to the cosmological distance ladder. WE start with simple ways of measuring distance we KNOW work. We can measure it right here in our chairs. For example, we KNOW parallax works. That's an easy way to get the distances to closeby stars. From there, we can use OTHER qualities of stars to determine the distances to stars and galaxies too far for parallax. We keep building up on things we KNOW the distance to to find the distances to things even further away.
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