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Reflecting about the book: "Just Six Numbers", Martin Rees

  1. Feb 11, 2016 #1
    Reflecting about that i.e. just 6 parameters whose value have to be like they are with a high degree of precision to have a universe like ours and that the probability for having those 6 values to be as they are should have a very low probability in connection with the theories about multiverse. They write that it may be that an infinite number of universes pop up and disappear, exist at the same "time", the concept of time and simultaneity are equally to be used in awareness of the concept in a context of science and physics and cosmology. It just is said it happens to be that only in this universe or those with equal values of i.e. those 6 numbers there is the possibility to have life and intelligence develop so that there are individuals who can reflect about this kind of questions.
    I did apply in my reflections this fact that a universe like ours is extremely unlikely to be but that still the event of such an universe is actually in place and the one in which we live.
    Why i.e can we not ask ourselves the question about how a such universe that is in extreme not probable would have to be without conflict of what we know about our universe and its laws of physics would have to be to make possible beaming yourself from any place in the universe to any other place in an economic and efficient way and that we could detect the property in an affordable and possible way within the reach of our technology and our science? I know, such an universe is totally not probable and its probability to be true is in extreme low. But is not our universe with its parameters of which the 6 numbers in the book of Martin Rees refer to also highly unlikely? So I am postulating that being in an universe whose defining properties require i.e. those 6 parameters to be as they are to a high degree of precision is not equally unlikely and why can we not happen to be in a universe where properties not being in conflict with what we know about the universe and that can be detected with our knowledge and science?
    If you apply additionally to this the concepts of those "parallel universes" next to each other like layers as some studies related to the string theories, the just by searching for such properties specified we might result of being in a "layer" that has this additional properties?
    As I wrote at the beginning, this are just reflections. But if I would be 4 decades younger than I am and would love physics as I have always done this would be a direction I would love to study and research! Just to put in relation as to how little we really know about how even just our universe is. Just a few years ago we had not even a clue about what euphemistically we call dark energy and dark matter. And this makes up the dominant part of what exists in our universe!
     
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  3. Feb 11, 2016 #2

    andrewkirk

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    The trouble with statements about the probability of the six numbers lying within the range that makes life possible is that they presuppose that we know a probability distribution for the possible values of such numbers.
    But we do not have such a probability distribution, and have no means of estimating one, so any statement about the probability of the numbers lying within any particular range - however narrow - is meaningless.
     
  4. Feb 12, 2016 #3
    One point of view totally valid and as correct as also the opposite opinion would be! The question is which point of view might open new fields of investigation! Your sentence at the bottom of your contribution should support my point of view: How can we judge something to be meaningless when we accept the concept that the universe could be more different from what we think and even so different that we would not even be able to suppose how it is?
     
  5. Feb 12, 2016 #4
    It seems to me that in the immediate aftermath of the big bang that a massive variety of initial particles would be formed.
    Some small subset(s) randomly happen to be able to mutually form stable groupings (the particles of the standard model, dark matter) and thus are more likely to persist.
    Other types of particles may exist that experience 'other' forces but are not able to find stable partnerships decay and are recycled.
    Over time (while the universe is still hot enough) particles pile up in the stable groupings and others disappear and are not now seen.
    So there is no need for miraculous pre-defined constants - the statistical variety of original particles and simple thermodynamic stability would probably result in a stable outcome in any hypothetical universe that did not collapse.

    Is there anything wrong with this conjecture ?
     
  6. Feb 12, 2016 #5

    andrewkirk

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    My comment about meaninglessness was solely confined to assertions that we have an idea about the probability that the universe would be the way it is.
    It is by no means meaningless to speculate on what the universe would be like if the six numbers were different. The whole genre of science fiction would be nullified if 'what if' speculations were considered meaningless. Speculation about things like collections of many spacetimes, each with different sets of numbers, are bread and butter for metaphysicians and speculative science writers, and there's absolutely nothing wrong with that.
     
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