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Inflation: Why all the 10^27s everywhere?

  1. Jun 7, 2009 #1
    I was reading about inflation on Wikipedia (warning: I don't really understand physics and cosmology) and I noticed that it said that inflation and dark energy were kind of broadly similar but that their energy scales were off by a factor of about 10^27. This weirded me out a little because I had also noticed that the figure quoted for the change in the size of the universe during the inflation epoch was thought to be around 10^26. Furthermore, the ratio of the current size of the observable universe (yeah, I know, "observable", but still a weird coincidence) to the size of the universe at the end of inflation was about 10^27. What's more, the ratio of the current age of the universe to the age of the universe at the beginning of inflation (yeah, I know, for the last one I said "end of inflation", but still a weird coincidence) is about 10^53, which is almost 10^27 x 10^27.

    Am I just going all numerologist here and making connections where there aren't any? If not, does anyone know why these numbers all turn out to be 10^27? Is there some kind of physical constant that comes into play in all of these or something?

    I really need to go see that movie "The Number 23".
  2. jcsd
  3. Jun 7, 2009 #2
    I was going to reference this, but you already did :frown:.

    I know that doesn't help your case, but I guess "It is what it is?". If it turns out to be something like the aforementioned movie, I would suggest getting your running shoes and preparing to head for the nearest hill.
  4. Jun 8, 2009 #3
    One of the first to notice these correlations of large numbers with theorist "PAM Dirac" He built a theory called "Large Numbers" based upon the idea that it was more than a coincidence that the strength of the electic field force and the strength of gravity (between for example a positron and and electron) was about 10^42 which is approximately the ratio of the size of the universe to the size of the electron. But the numerology didn't stop there - the critical mass in the universe is on the order of the square of the radius (10^26) = 10^52 ...and there are some others - my personal belief is that these ratio's are telling us something deep - as opposed to Planck numbers which are quoted in almost every cosmological paper as sacrosanct -

    Let the hammer fall
  5. Jun 8, 2009 #4
    Wait, a mass is the square of a distance? Looks like you may have something mixed up there.

    Planck numbers? Are you talking about Planck units? What do you mean by "sacrosanct"? I thought these units were used because they are convenient.
  6. Jun 8, 2009 #5
    Also, when you say "the radius", you mean the radius of the observable universe, or what? We don't know the radius of the whole universe, right?
  7. Jun 9, 2009 #6


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    Dont read too much into wiki, too much crackpot there. numerology - perhaps. what do you think? the observable universe has a radius of about 13.3 billion light years [light travel time].
  8. Jun 9, 2009 #7
    The Hubble Radius is about 10^26 meters - there are some transformations that express various cosmological factors in terms of units of distance - Harrison in his book "Cosmology" has an entire chapter on the subject of the cosmic numbers, large and small
  9. Jun 9, 2009 #8


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    Haven't you heard the latest measurement of the diameter of entire universe? It's about 156 billion light years wide. No kidding, most part of the universe moving away with the speed of up to 12 times faster than light.
  10. Jun 10, 2009 #9
    isn't the accepted figure, 45 billion light years radius? And the minimum radius of curvature is 100bly

    What's the definition of a coincidence anyway?

    The human brain is remarkably good at taking random chaos and recognizing patterns where there are none.
    Last edited: Jun 10, 2009
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