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Help! Visualisation and Stats for a Determinist

  1. Mar 23, 2007 #1
    Hello,
    I am a new user here. Before I go any further I would like to say "hi" to all members.
    Now on with the post (and I hope I have chosen the right forum).
    I am a bit of a philospoher and am a "determinist" ie. believe that my actions and thoughts etc are basically a product of the forces of nature. By forces I do not mean exclusively the strong and weak forces etc exclusively, but more generally events in the material world such chemical reactions, processes of evolution, self organisation and socialpsychological interaction also (and the list goes on).
    So why have I posted here?
    Well earlier today I said that I 'was the product of every event that has ever been'. Within moments I realised my mistake. The universe is around 13'5 billion years old but 156 billion light years across (due to accelerating expansion. Therefore events on the other side of the cosmos, or anywhere over 13.5 billion light years away, could not have affected me, as information can not travel faster than the speed of light.
    So I come to a visualisation. There is a "sphere" with a radius of 13.5 billion light years and and age of 13.5 billion years, within whose walls are contained all of the possible events that could have ever affected me.
    That sounds ok, fairly reasonable, untill one recalls that 13.5 billion years ago the matter in the universe was crammed into a singularity (I know there are alternatives to the singularity model in a 'cyclic model' cosmology) or something like that. Anyhow there cannot be a true SPHERE 13.5 billion years old.
    I have become stuck, my physics knowledge will not help me any further.
    Now you can probably see why I titled my post in the way I did. What I want is some kind of visual model for the "sphere" or possible space of influences that could have affected me since the beginning of time as we know it. It started off with a "bang" and now it looks, and looked, like? How has it evoved over time?
    Also what I want to know is within that sphere what proportion of the total number of events could have affected me, and what proportion of the universe does that sphere take up, but now and in the past as the cosmos evolved?
    The answers to these questions would blow my mind, and I would be very thankful if you could help me in any way at all.
    Finally, I hope I have chosen the right forum tor this type of question.

    Yours sincerely,

    Luke.
     
  2. jcsd
  3. Mar 23, 2007 #2
    The sphere is "your past light cone".

    All events in it may in principle have affected you, asking for the proportion is like asking how much a given butterfly impacted todays weather.

    The universe is "most likely" infinite, in which case the proportion in your past light cone is practically zero (though the universe could be finite, or if you trace back to the singularity perhaps in some sense it was all in your past light cone).
     
  4. Mar 24, 2007 #3
    I don't understand! If the universe is 13.5 billion years old and it all started as a singularity with a "big bang", and nothing can go faster than the speed of light (c), how can the universe be larger than a sphere with a diameter of 27 billion light years?

    Maybe this question has been answered in another section of this forum.
     
  5. Mar 24, 2007 #4

    Garth

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    Gold Member

    Nothing can go faster than the speed of light locally through the space-time manifold.

    It is space itself which is expanding cosmologically that carries the galaxies along with it.

    At a great enough distance those galaxies or quasars can travel faster than light relative to us and yet under some conditions we can still see them!

    We can still see some faster-than-light objects because the light from those objects itself is carried along with the expansion of the universe.

    I hope this helps.

    Garth
     
  6. Mar 24, 2007 #5
    Light cone? Yhankyou! I'll look into it/them. After a brief scan of wikipedia etc I get the concept but not the calculations.

    Butterfly? Yes, I think you're reffering to chaos theory there, the basic premmises of which I have a grasp of.

    Infinite. Yes. I take that as meaning without beginning. Therefore practically zero? ie. Of infinite events the ones that lead to finite me are infinitesimally small?

    Singularity? Do you mean back then all marret was interacting and I am (for practical intents from the determinist pov) a product of all of those interactions?

    Here are some of the calculations I have been pondering.

    I have read here that the mass of the universe is 3 x 10 raised to the power of 55 (grammes). If we assume that the total mass includes the total of causes and half the mass half the causes, then we can say that a roughly 100kg or 100,000 grammes man such as myself is a function of x number of causes where x is the my pass divided by the total mass, or erm let me guess, an educated guess, something like 0.00 (and another 47 zeros)0333333333reccuring% of all causes. Or about two units of a google percent.
    Do you think that a calculation type such as this is valid?

    There is a online light cone calculator here and mine will expend to HR9038 in 10 months time, but that is not my past light cone though. Iota Persei was enveloped by my light cove 7 days ago. Does that also mean that 7 days ago Iota Persei became part of my past light cone, as light travelling from me and from it travels at the same pace?
     
  7. Mar 24, 2007 #6
    % of causes.

    Now the mass of the universe is 3 x 1055 g , and my average weight throughout my lifetime is about 50,000g (50kg). My proportion of the total is therefore 5 divided by 3*10 to the 51,
    or about 1.7 * 10 raised to minus 51...% of the total.

    Now I have been around for 30 years and the universe about 15 billion. I have therefore been around for about 2 *10 raised to minus nine...% of time.

    Therefore the estimated percentage of causes total causes ( which lead me to type this) is
    3.4 * 10 to the minus 60, or 3.4 novemdecillionths of all causes.
     
  8. Mar 24, 2007 #7
    The universe is about 13.7 billion years old. Light reaching us from the earliest known galaxies has been travelling, therefore, for more than 13 billion years. So one might assume that the radius of the universe is 13.7 billion light-years and that the whole shebang is double that, or 27.4 billion light-years wide.

    But the universe has been expanding ever since the beginning of time, when theorists believe it all sprang forth from an infinitely dense point in a Big Bang.

    "All the distance covered by the light in the early universe gets increased by the expansion of the universe," explains Neil Cornish, an astrophysicist at Montana State University. "Think of it like compound interest." (source)
     
  9. Mar 25, 2007 #8
    One's assumption would be wrong (and somewhat naive, to assume that one is the centre of the universe).
     
  10. Mar 28, 2007 #9
    "I" didn't write that. It was copied and pasted from another source - the MSN science and technology dept.

    I thought that "everywhere" was the centre of the universe, just as everywhere/ anywhere is the central point on the surface of a sphere...
     
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