Big bang - put bigger thing into smaller container?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by Saint, Feb 8, 2017.

  1. DaveC426913 Valued Senior Member

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    Saint, I suspect you are not reading responses to your posts.

    Theory schmeery; We observe it. That's empirical observation.

    Sirius B is a nearby white dwarf. We know its diameter and we know its mass. Its density is about 1000 kg per cubic cm.

     
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  3. James R Just this guy, you know? Staff Member

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    Saint:

    I am sorry that part of your thread has been taken up with criticisms of paddoboy's posted explanation and article attribution.

    Conditions here and now on Earth are not the same as conditions in the very early universe. Nor are the same as in various astronomical scenarios, as others have pointed out.

    If it is impossible to put a truck-sized rock into a cup here and now, that does not mean it cannot be done elsewhere or at another time.

    We know of objects such as white dwarf stars and neutrons stars when a truck-sized rock is readily compressed to cup-size. Obviously, here on Earth there are no convenient white dwarf stars that we can use as compressors.

    Tune your radio to a static channel. Part of the noise you hear is the remnant of the big bang. In a similar way, the microwave background radiation that is observed by astronomers is clear evidence of the big bang. Other evidence includes the observed ongoing expansion of the universe, and the observed ratios of hydrogen to helium in the universe.

    The big bang is a theory. Like all powerful theories in science, it is supported by many different pieces of evidence from many different kinds of observations. If you're interested, there is a lot of information available on specific evidences on the internet. Try a google search for "evidence for big bang", for example.

    The prevailing view at the moment is that a "big crunch" won't happen. The universe appears to be expanding at an accelerating rate.

    This is what astronomers do all the time. They make observations that may or may not turn out out to be consistent with theories such as the big bang. Right now, the the evidence supports the big bang theory.

    Which theory, in particular? Physics as a whole is interlinked, so that few areas are ever completely separate from each other. No experiments that have been done are inconsistent with the big bang theory, as far as we can tell. Moreover, the big bang theory itself draws on what is known from countless experiments in other areas of physics.

    To give you a practical example, it is conceivable that the Large Hadron Collider could turn up some evidence about how fundamental particles behave that would mean that the big bang theory was no longer a possible explanation for the origin of the universe. However, to date it has not done so. In fact, the results are helping to inform and develop the big bang theory.

    One more point: you asked about singularities. You need to be careful to distinguish between a mathematical singularity and a physical singularity. A mathematical singularity is something that usually gives a seemingly nonsensical result - like dividing a number by zero. A physical singularity might be some aspect of the physical world that is actually infinite (for example).

    You may have heard the term "singularity" in reference to black holes. The general theory of relativity produces a mathematical singularity at the centre of a black hole, and also at the event horizon in some coordinate systems. But it turns out that the the singularity at the event horizon can be removed using a mathematical "trick" of changing coordinates. This tells us that there isn't a physical singularity there. As for the centre of the hole, the singularity there, as predicted by GR, does appear to be a physical one. Most physicists therefore view general relativity as flawed when it comes to describing the very centre of a black hole. Moreover, we have a good reason for believing it is flawed, namely that general relativity is not a quantum theory. So, improving our theories is an area of very active research.
     
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  5. RajeshTrivedi Valued Senior Member

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    so, where is the observation of big bang?

    I do not see how the CMB is the observation of Big Bang. Yes, it is right CMB can be explained under Big Bang Cosmology and other alternatives get somewhat stuck in explaining the CMB.

    It is incorrect to say that CMB is everywhere in the universe, we have no such observational data.
     
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  7. Russ_Watters Not a Trump supporter... Valued Senior Member

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    It is not an observation of the Big Bang, it is an observation of the surface of last scattering, which IIRC came a few hundred thousand years later.
    Right. What we can say is that it comes form every direction. It implies it can be observed from everywhere, but it hasn't actually been observed from anywhere else.
     
  8. river Valued Senior Member

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    Really Russ ?

    We know or should know that CBM , is only elimiated ; as a source of , CBM , from very , very , very , close galaxies .

    We can not assume that CBM , is true evidence of BB .
     
    Last edited: Feb 10, 2017
  9. James R Just this guy, you know? Staff Member

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    The cosmic microwave background radiation is, to a good appropximation, the same in all directions. It is not associated with particular galaxies, as far as we can tell.

    Nobody assumes that CMB is true evidence of the big bang. What we can say is that the observed CMB is consistent with what we would expect to see if there was a big bang. And that's putting it is the least generous terms possible.
     
  10. river Valued Senior Member

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    CBM IS associated with galaxies , for they can be a source of CMB's .

    Hence distort the any thinking ; that CMB's are a proof of BB theory .

    The more galaxies that are elimated as the source of CMB's the better .
     
  11. paddoboy Valued Senior Member

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    No wrong: The source of the CMBR is everywhere independant of galaxies.
    In fact the four pillars that support the hot BB/inflationary theory of universal evolution, and the reasons why it is accepted as most likely are....
    [1] Universal Expansion:
    [2] The relic heat of the BB, or the CMBR:
    [3] Abundance of the lighter elements:
    [4] Large scale galactic structure:
     
  12. DaveC426913 Valued Senior Member

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    And even this is an understatement in the extreme.

    The following graph is actually two graphs in one.
    The green line is a mathematical representation of what, according to the BB theory, the CMB should look like. It is a prediction.
    The red marks are what was actually observed.
    The differences between predicted values and observed values are so small that error bars on the graph are too small to be seen at this scale.

    This single diagram is one of the most spectacular exemplars in the history of physics of observations corroborating an existing theory.

    Please Register or Log in to view the hidden image!

     
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  13. DaveC426913 Valued Senior Member

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  14. paddoboy Valued Senior Member

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    Who's XKCD?
     
  15. DaveC426913 Valued Senior Member

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    Only some of the most cuttingly witty sciencey stuff on the interwebs is all.

    It is where this came from:

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    Go here:
    https://xkcd.com/

    See you in about a week.

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    Special mentions:
    The Up-goer Five: https://xkcd.com/1133/
    Someone is wrong: https://xkcd.com/386/
     
  16. paddoboy Valued Senior Member

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    Vinaka vakalevu! great stuff!!!!
    Should put our conspiracy/Woowoo brigade to bed for a while.
     
  17. river Valued Senior Member

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    Wrong

    Every galaxy is a source of MR .

    ASTROPHYSICS AND ASTRONOMY knows this .
     
  18. DaveC426913 Valued Senior Member

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    It is true that there are sources of microwave radiation.
    What is being discussed here is what's left over after we account for sources - microwave radiation that is not associated with any specific source - it is uniformly distributed, no matter where we look. Indeed, the fact that it is very evenly distrubuted - no matter where we look in the sky - is one of the determining factors that point to its origin in the BB.
     
  19. paddoboy Valued Senior Member

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    Yes, but every galaxy does not contribute to the CMBR everywhere.
    We are talking of millions of L/years between galaxies...
    And of course the graph by Dave.

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  20. river Valued Senior Member

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    So in your post #48 you lied .

     
  21. paddoboy Valued Senior Member

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    No river, don't be silly, again.
    You are claiming galaxies are "the" source of MR...The CMBR is spread out uniformly throughout all of spacetime everywhere at a constant 2.73K....and again, please visit Daves graph.
     
    Last edited: Feb 10, 2017
  22. James R Just this guy, you know? Staff Member

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    The cosmic microwave background (CMB) radiation generally refers to the isotropically distributed radiation in the microwave region that is observed in all parts of the sky.

    Galaxies certainly emit microwaves, but they do not do so evenly over all parts of the sky.

    Nobody says the CMB is proof of the BB theory, as I explained above.

    What makes you think that hasn't already been taken into account?
     
  23. river Valued Senior Member

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