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Help, I a newbie

  1. Jul 24, 2008 #1

    With the present understanding of the age of the universe (acceleration and temperature), how long before the universe is cool enough to support our type of life?


    If the Earth existed since the BB, how long would we see a red sky at night from the after glow of the big bang? I guess size and time would be important here.

    Quark star?

    If there is a quark star,
    What would the minimum mass of such a star be?
    Could light escape its surface?
  2. jcsd
  3. Jul 24, 2008 #2


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    Staff: Mentor

    Thread moved from Cosmology to Homework Help.

    I'd say it's supporting it right about now, no?
  4. Jul 24, 2008 #3
    as an ex moto-x'er myself maybe I was not clear.

    How long after the BB I mean.
    I read some numbers a while ago and can not remember where.

    This is actually not homework.
    An “I do not know” or “please clarify” is an acceptable answer.
  5. Jul 24, 2008 #4


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    Staff: Mentor

    Guess I'll move it back to Cosmology then. There's not much on the BB at Hyperphysics, but there's a reasonable intro at wikipedia.org (always be careful about the accuracy of articles at wikipedia, though), including some timeline info. It doesn't exactly address your first question, though.

    And on your 2nd question, you might want to re-word it, since the Earth wasn't around since the BB, just the matter that ended up in the Earth.
  6. Jul 24, 2008 #5


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    That isn't too easy to answer exactly but I think you can get a reasonable idea this way. It's pretty convincing to expect that stars and planets must have formed in order for life anything like the life here on Earth to have evolved. So...

    The first stars seemed to have formed sometime in the first billion years. However for planets to form you need some heavier elements to be cooked up in stars. This could take anywhere from a few million years (for really large stars) to a few billion years (for smaller stars). But it does seem likely that sufficient heavier elements might be available in perhaps 100 million years. So a resonable estimate for the earliest possible appearance of life might be from say 800 to 1200 million years after the BB.

    The Earth couldn't have existed from the BB but hypothetically you'd have seen a bright sky right up until the time of last scattering some 400000 years.

    Sorry, I don't have even a guess for your last question.
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