Illustrating Olbers' paradox

Discussion in 'Astronomy, Exobiology, & Cosmology' started by humbleteleskop, May 29, 2014.

  1. humbleteleskop Banned Banned

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    Do you still claim to know what would be the amount of radiative flux in Olbers' paradox universe? Is that number infinite maybe?


    So you acknowledge then the paradox conclusion is based on the premise that infinite number of stars would be visible and all contribute to the total brightness? And such infinite brightness is not different much than non-infinite brightness, it's a valid premise you say?
     
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  3. Russ_Watters Not a Trump supporter... Valued Senior Member

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    Lol, you asked for an explanation! Is this your way of saying "oops, I should have known that, now I have to find a way to attack so I can slink away?"
    The number I gave you is not infinite and has not changed.
    I decline to answer this question anymore, as I have already answered this half a dozen times and you keep saying the opposite of what the truth is and falsely attributing it to me.
     
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  5. humbleteleskop Banned Banned

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    You did not give any number, you every time refused to answer that question. Maybe you are again referring to your ridiculous "one pixel in the 1st shell" calculation and this number: 0.0010 w/sq m? Is that your answer? How many shells were there in your calculation?


    Decline?! That's all you have left, huh? It's embarrassing.

    a.) Olbers' paradox conclusion is based on the premise that infinite number of stars contribute to the total brightness. Yes, no?

    b.) Supposing that infinite number of stars contribute to the total brightness is a false premise and makes the paradox flawed. Yes, no?

    Please make yourself clear and explain your opinion.
     
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  7. Russ_Watters Not a Trump supporter... Valued Senior Member

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    Post 226.
     
  8. humbleteleskop Banned Banned

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    Why can you not understand the rate of energy received depends on the distance?

    Every line of sight ends on a star, and how many stars are in that equation, infinite or less than infinite?


    a.) Olbers' paradox conclusion is based on the premise that infinite number of stars contribute to the total brightness. Yes, no?

    b.) Supposing that infinite number of stars contribute to the total brightness is a false premise and makes the paradox flawed. Yes, no?

    Please make yourself clear and explain your opinion.
     
  9. RJBeery Natural Philosopher Valued Senior Member

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    In Olber's toy universe all stars are giving off the same amount of energy, meaning they are emitting photons of the same wavelength. Photons do not lose energy as they travel regardless of distance.
    The answer is actually finite. "Line of sight" isn't a 1-dimensional line; any photo receptor must have an area.

    No. If this were true then Olber's sky would be infinitely bright and it is not.
    I agree, that would make for a flawed paradox, but Olber presumes that light approaching us from behind another star cannot penetrate it. This is why the sky in Olber's paradox claims that the sky would look just as the surface of a single star.
     
  10. humbleteleskop Banned Banned

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    Emitted photons are not received photons.

    Please Register or Log in to view the hidden image!


    http://en.wikipedia.org/wiki/Inverse_square_law


    If not infinite, then what number is it, 10, 53, 278?


    What equation are you looking at? If not infinite, then what number is it, 10, 53, 278?


    That is not part of the equation. The paradox calculation either presumes infinite number of stars contribute to the total brightness, or not. That's all it matters.
     
  11. RJBeery Natural Philosopher Valued Senior Member

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    You are not accounting for a quantized universe. The inverse square law only applies on a macro scale, not individual photons. The number of stars it would take to fill the sky would depend on the star sizes, their density in the sky, distance from us, etc, but it is not infinite. Think about looking through a forest; does it take an infinite number of trees to see nothing but wood?

    I'm not even sure what your point to all of this is. You're trying to force a malformed setup of Olber's Paradox so you can claim it is false..? I've already agreed with you that your interpretation of Olber's Paradox would indeed be false. Isn't it possible that your interpretation is wrong?
     
  12. humbleteleskop Banned Banned

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    Intensity exactly is the number of photons per unit time per unit area.


    The paradox, we are talking about Olbers' paradox. The paradox calculation either presumes infinite number of stars contribute to the total brightness, or not. If it is not infinite, then what number is it?


    The premise of the paradox is either valid or invalid, there is no "would be". Is the premise that infinite number of stars would contribute to the total brightness valid premise, or invalid premise? It's invalid premise. Does paradox calculation uses that premise? Yes. Therefore, the paradox is flawed.
     
  13. Russ_Watters Not a Trump supporter... Valued Senior Member

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    1. Why did you claim I refused to answer when clearly you were aware I did answer?
    2. When the photons come from everywhere, distance doesn't matter. That's what the equation is for!
    Post 228.
     
  14. Russ_Watters Not a Trump supporter... Valued Senior Member

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    The forest analogy is a good one: you don't need to know how many trees there are to know every line of sight through a forest ends on a tree. Olber didn't make any calculations as far as I'm aware - he understood the logic well enough that he didn't have to.
    You know that isn't true, which makes it a lie.
     
  15. RJBeery Natural Philosopher Valued Senior Member

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    Jesus humbleteleskop I think you're being intentionally obtuse here. The main idea is this: an infinite number of stars would make the sky uniformly bright. It just so happens that a finite number of stars of a certain size and density would also make the sky uniformly bright. Since the sky is not uniformly bright, there must not be an infinite number of stars (unless there is another reason for the sky to look the way it does, such as an expanding universe of finite age, etc)
     
  16. humbleteleskop Banned Banned

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    Photons do not come from everywhere at the same rate, the rate depends on distance.


    Russ_Watters #228:
    - "you do recognize that some number of shells have to be added together to produce the final image, right?"

    So again, what is the number of shells in your equation, infinite or finite?


    Please point the paradox equation where you see it considers some finite number of visible stars, rather than assuming the number is infinite.
     
  17. humbleteleskop Banned Banned

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    You are contradicting yourself.

    Russ_Watters #228:
    - "you do recognize that some number of shells have to be added together to produce the final image, right?"


    a.) the number of shells in the paradox equation is finite

    b.) the number of shells in the paradox equation is infinite

    c.) the number of shells in the paradox equation is undefined


    Make yourself clear.
     
  18. humbleteleskop Banned Banned

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    There is no "if", there is no "would be", there is the paradox and you either understand its equation or you do not.

    a.) the number of shells in the paradox equation is finite

    b.) the number of shells in the paradox equation is infinite

    c.) the number of shells in the paradox equation is undefined
     
  19. RJBeery Natural Philosopher Valued Senior Member

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    I'm unsubscribing from this thread. Good luck with your claim to fame...
     
  20. Russ_Watters Not a Trump supporter... Valued Senior Member

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    Doesn't matter how many times you say it, it won't ever become true. Let's try this:
    1. You know every shell sends the same number of photons.
    2. You know the stars in every shell cover the same total area of the sky.

    So when covering the whole sky, the intensity is uniform.

    And you didn't answer my question: why are you lying about me not answering your questions? For that matter, why are you lying about your own understanding?
    Nope, that wasn't it. Try again.
    As far as I know, Olber didn't do any calculations. He didn't need to. Again: Why are you lying about what the paradox says?. This must be a lie because you understood it before.
     
  21. humbleteleskop Banned Banned

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    Ignorance is not a virtue, stop making fun of yourself.

    NASA: - "In an infinite universe, which has existed forever, we shouldn't have night. Imagine a universe divided into shells, with stars of a single brightness distributed evenly --- if you look at a shell twice as far, each star is only a quarter as bright, but there are four times as many stars, so each shell is equally bright. If you have an infinite number of shells, you end up with infinite brightness!"

    http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980815b.html


    Do you acknowledge?
     
  22. Russ_Watters Not a Trump supporter... Valued Senior Member

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    Acknowledge what?
     
  23. humbleteleskop Banned Banned

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    That's right, you do not know. And if you keep pretending that you do, you will never learn. This is how the calculation and the conclusion goes:


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    Since the area of a sphere of radius r is

    A = 4p r2 (1)

    the volume of such a shell is

    V = 4p r2t (2)

    If the density of each of the luminous objects within the shell is "n", then the total number of these objects in the shell must be

    N = 4p r2nt (3)

    Now let us ask just what amount of energy such a shell will send to the Earth. Since the shell's thickness is small, it is reasonable to assume that the entire shell is at a distance "r" from the earth. The energy, E, emitted by any source at distance r, produces an intensity, "I", over a given area, A, on the Earth of (inverse square law)

    I = E/4p r2 (4)

    The total intensity received on the Earth from all the sources in the shell r units away must then be the intensity produced by each source times the total number of sources or

    T = IN (5)

    Substituting the value of N previously calculated into the above, we find that

    T = tnE (6)

    We notice at once that the total energy received from any chosen shell does not depend upon its distance from us (no r in the above equation). The total energy received from all the shells is the sum of the contributions of each shell. If there are M shells this total is

    S = tnEM (7)

    But there is an infinite number of shells and so the total intensity on the earth must be infinite. Therefore, the nighttime sky should be blindingly bright!
     

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