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B Are universe and big bang considered to be the same thing?

  1. Jul 11, 2016 #1
    Do professionals use the term universe to mean what was created in the big bang?
     
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  3. Jul 11, 2016 #2

    ProfuselyQuarky

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    The "universe" is all of space and time and all of the matter and contents within. The Big Bang is simply a theory that scientists believe explain how the universe is created.
     
  4. Jul 11, 2016 #3

    timmdeeg

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    Yes
     
  5. Jul 11, 2016 #4

    phinds

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    Uh, quarky, that's not right (It is a pop-sci point of view). The Big Bang Theory says NOTHING about how the universe was created. It is a description of how the universe has evolved from approximately one Plank time after the singularity up to the present. The singularity is not part of the Big Bang Theory because we don't know what it was physically.

    EDIT: Actually, let me amend that statement. If by "the big bang" you mean "the big bang singularity" then yeah, I guess it's right to say that's what created the universe but the problem you run into is that people then conflate that with the belief that the Big Bang Theory describes the creation, which it does not. The "singularity" and the "theory" are radically different things and it's important to keep in mind that the big bang singularity was not an explosion; we don't know what it was, which is why it's called a singularity.
     
  6. Jul 11, 2016 #5
    I would say that the universe is the (for lack of a better word) stuff, and the big bang describes how it's evolved. The universe would still exist if it didn't "bang." If the universe had not expanded, and instead collapsed in on itself, there would never have been a big bang, but there would still be a universe.
     
  7. Jul 12, 2016 #6

    bapowell

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    The Big Bang theory describes the evolution of the observable universe from an early hot, dense state to our present epoch.
     
  8. Jul 12, 2016 #7
    Good point, The Big Bang presumes nothing about the parts of the universe that we can't see.
     
  9. Jul 12, 2016 #8

    ProfuselyQuarky

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    Yes, you're right. That's wrong. The fact that Big Bang Theory and Big Bang Singularity are so very similar (word-wise) always gets me. Sorry.

    The answer to the OP is still yes, nonetheless.
     
  10. Jul 12, 2016 #9

    timmdeeg

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    Yes. Unambiguous question allows short answer. :smile:
     
  11. Jul 12, 2016 #10

    ProfuselyQuarky

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    Haha, yes, that's true.

    On the plus side, I got corrected on something, so this thread served its purpose. :smile:
     
  12. Jul 12, 2016 #11

    phinds

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    I disagree. When the short answer itself can lead to confusion, as it can in this case, then I think the longer answer is called for.
     
  13. Jul 13, 2016 #12

    timmdeeg

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    And I don't see your point. In my opinion, the question "Do professionals use the term universe to mean what was created in the big bang?" can be answered with yes or no.
    Why leads the answer "yes" to confusion?
     
    Last edited: Jul 13, 2016
  14. Jul 13, 2016 #13

    phinds

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    Read post #4
     
  15. Jul 13, 2016 #14

    timmdeeg

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    Well post #4 is not an answer to the OP, it is commenting on something else.
     
  16. Jul 13, 2016 #15

    phinds

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    Jeez, fella, you asked what is potentially confusing and I answered you. It seems you are being argumentative just for the sake of being argumentative. That's MY job here :smile:
     
  17. Jul 13, 2016 #16

    PeterDonis

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    Thread closed for moderation.
     
  18. Jul 13, 2016 #17

    PeterDonis

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    This isn't quite right either. The Big Bang theory starts with the hot, dense, rapidly expanding state that existed at the end of inflation. That was not one Planck time after the singularity; in fact, we don't even know that "time after the singularity" has any meaning at all. The numbers that are quoted in pop science sources (and even in some of the literature) for "time after the singularity" refer to a mathematical model with no inflation that does not represent what anyone believes actually happened. But even if we accept those numbers as notional numbers, the "start time" of the standard hot Big Bang theory is not one Planck time after the singularity.
     
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