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Would a human be able to see a nebula if they were close enough?

  1. Jul 24, 2010 #1
    Would the human eye be able to pick up a picture from the Hubble Telescope unaided if it were close enough? For instance, how close would I have to be to the Pillars of Creation in order for it to fill my entire field of view if I were floating in outer space? I assume several hundred light years away from it in order for me to be able perceive something so massive in my field of view, but if I am that far away can the human eye even see things that far away in space?

    Thanks!
     
  2. jcsd
  3. Jul 24, 2010 #2

    russ_watters

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    It's really a matter of brightness of the nebula. The Orion Nebula is right on the edge of the human visual range and would be visible easily if we were closer to it. But no nebula would ever look anything like what a telescope photo looks like.
     
  4. Jul 24, 2010 #3
    Oh wow, I suddenly feel really gullible: then what is it we're seeing in those nebula pictures?
     
  5. Jul 24, 2010 #4

    russ_watters

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    What do you mean? What does gullibility have to do with anything? Obviously, when we see a picture of a nebula taken through a telescope, we're seeing the nebula as it looks to a telescope with a camera. Since human eyes are nowhere near as sensitive as a telescope with a camera, what it looks like to the naked eye is nothing like what it looks like to a telescope with a camera. It shouldn't be distressing to find that out.

    Besides the brightness itself, our vision at night is almost completely devoid of color because the sensitivity of our eyes to color is much lower than the sensitivity to monochromatic light.

    Consider the Andromeda Galaxy. It is so big in the sky that it dwarfs the full moon - it is something like 4x as big. But does it look anything like this to your eyes?: http://artsandsciences.ca/wp-conten..._-_The_Andromeda_Galaxy_M31_Spyral_Galaxy.jpg
     
    Last edited: Jul 24, 2010
  6. Jul 24, 2010 #5
    Okay I thought you were implying we're actually looking (with the telescopes) with different frequencies (like IR) and translating them back to visible light. If not, what could be the difference between a telescope view and a human eye view?... (must be missing something obvious here)
     
  7. Jul 25, 2010 #6

    russ_watters

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    Like I said, brightness and color. Again, consider the Andromeda Galaxy. It's up right now and it's huge. But I bet if you go outside you wouldn't even be able to find it!
     
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