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Re: Big bang theory changing

  1. Jan 2, 2015 #1
    I was watching the news the other day and saw an article about scientist rethinking on the big bang. The article
    stated that some scientist believe that there had be something else that occurred for everything to evolve as far as it has in the amount of time since the so called big bang. Can anyone elaborate on this? I'm no scientist I just love stuff about our great universe!
     
  2. jcsd
  3. Jan 2, 2015 #2

    phinds

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    The Big Bang Theory is a theory of the evolution of the universe starting at about one Plank time after the "big bang singularity" and does not describe the singularity (the place where the model breaks down) or how everything started, it just describes what happened since then. It has at least one major open issue, whether or not "inflation" really happened but otherwise does a GREAT job of describing everything from the physical element distribution to the expansion of the universe and the acceleration of that expansion.

    Any "new" theory will have to do AT LEAST as good a job of explaining and whole TON of stuff and that's not likely (although not impossible).

    And by the way, do NOT believe science you read in the newspaper and particularly not what you see on television. They get stuff right from time to time, mostly by accident, but they get a huge amount wrong and you'll never know which is which if those are your only sources for science.
     
  4. Jan 2, 2015 #3

    Bandersnatch

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    This might just be about inflation. We can't really comment to the point without knowing what was actually said. Can you provide a reference?
     
  5. Jan 5, 2015 #4
    No it was something I read along the bottom of the news cast. As I am hearing impaired [Not Deaf] I watch a lot of what's written if available. And you are correct
    A person certainly can't trust any news organization. Is Universe Today a good source.
     
  6. Jan 5, 2015 #5

    marcus

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    I watch the professional literature in cosmology, scan the new titles every day or so, look at some summaries, read a few. My impression is that the changes to the basic model that people are studying only have to do with a small fraction of a second around the start of expansion.
    I basically agree with Phinds and Bandersnatch here. The standard classical model works really really well once you get it started. Impressive fit to tons of data. But it breaks down right at the start.

    So what people typically want is a model that does not break down at the start of expansion but which recovers the successful model after a brief interval of time---essentially duplicates its numerical predictions.

    What Bander said about the "inflation" issue rings true. Inflation scenarios presuppose mythical "inflaton" fields which are like nothing that has ever been observed. On the other hand the scenarios EXPLAIN some things: the approximate even distribution of stuff, the uniformity, the approximate sameness of temperature of the ancient light coming from different directions. And also when it comes down to the tiny fluctuations of temperature which speckle the sky with many different size speckles, there is the challenge to explain the STATISTICS of those speckles. How many dents and bumps of different sizes? How much fluctuation at different angular size wavelengths?
    That is called the "CMB power spectrum" it just means the STATISTICS of the fluctuations in the ancient light sky map (those blue and red speckled oval maps you see.

    Inflation scenarios are not the only way to explain these observed things: approximate uniformity, sameness, the levelness of the "CMB power spectrum", its slight bias in favor of larger fluctuations (the so-called "red tilt"). I think it is important to keep an eye out for news of other ideas about what could have been happening in the first fraction of a second which might explain the same observations. But IMHO the main overall theory (after that brief startup period) is not showing signs that it is going to change much.

    H012, I'm not suggesting you watch the new papers listings in cosmology, many are so technical it would be too confusing to even begin to try, but you might want to glance at the list now and then:
    http://arxiv.org/list/astro-ph.CO/recent
    If you go there and see a paper with an interesting title, you can click on the arXiv number and see a short summary, or you can click on "pdf" and get the whole article to look at. It will usually have an introduction section and a conclusions section a the end which try to say in words, without equations, what it is about and what their findings were.
     
    Last edited: Jan 5, 2015
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