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  1. #1
    George Dingwall's Avatar
    George Dingwall Guest

    Default The Age and Size of the Universe.



    Hi there,

    I was watching a TV program yesterday called "Beyond the Bigbang". A
    statement was made in the program that the universe was about 13.7
    billion years old and that the known universe was something over 150
    billion lightyears across.

    Now, assuming that the universe is expanding equally in all
    directions, how do you get from the point of origin of the big bang
    out to a distance of more than 75 billion lightyears in only 13.7
    billion years?

    This stuff really confuses the hell out of me. :-)

    Bye for now.
    Bye for now,

    George Dingwall

    Invergordon, Scotland

    http://www.georgedingwall.co.uk

  2. #2
    Iordani's Avatar
    Iordani Guest

    Default The Age and Size of the Universe.

    George Dingwall wrote:


    There is no point of origin. (Or, all points are equally original)
    Not that this answer will make it less confusing...


    I'd guess that Life, the Universe and Everything is equally confusing for
    all who live here

  3. #3
    Steve Wolstenholme's Avatar
    Steve Wolstenholme Guest

    Default The Age and Size of the Universe.

    On Sun, 04 Nov 2007 13:48:43 +0100, Iordani <somewhere@earth.net>
    wrote:


    If the Universe wasn't confusing very few people would study it.
    Fortunately it gets more confusing with more study.

    Steve

    --
    Neural Planner Software Ltd

    http://www.easynn.com
    http://www.tropheus.demon.co.uk

  4. #4
    George Dingwall's Avatar
    George Dingwall Guest

    Default The Age and Size of the Universe.

    On Sun, 04 Nov 2007 13:48:43 +0100, Iordani <somewhere@earth.net>
    wrote:


    If the origin was the bigbang when all energy and matter in the
    universe occupying a volume of less than the smallest sub-atomic
    particle, it either had a finite size or no size at all.

    So my question is this. If they now know that it has a volume which is
    150+ billion light years across, then it must have occupied a smaller
    volume in the past. So how did it manage to expand from virtually
    nothing to 150+ billion lightyears across in only 13.7 billion years.

    Surely anything that existed shortly after the bigbang could not now
    be more than 70 billion lightyears away from its original position.

    Bye for now,

    George Dingwall

    Invergordon, Scotland

    http://www.georgedingwall.co.uk

  5. #5
    Paul Smith's Avatar
    Paul Smith Guest

    Default The Age and Size of the Universe.

    "George Dingwall" <george.gdingwall@virgin.net> wrote in message
    news:m2pri3dqsph48lrdvvbrdm7eern6df4lkr@4ax.com...


    Well it no doubt had a size when space-time formed at that moment.


    The radius for the visible universe is 13.7 (well minus about 300,000 years
    for the cosmic microwave background). When people talk of the size of the
    universe typically they refer to the visible, or known universe.

    Figures bigger than that, are as far as I know estimates based on things
    like inflation, the microwave background etc.


    Sure, but relative to what? Maybe it is in more or less its original
    position, its position relative to something else in the universe could
    quite easily be 70 billion light years distant. Space-time itself is not
    bound by the speed of light, during inflation the universe expanded much
    faster than the speed of light.

    At the moment the universe is expanding at about 70 km/s per megaparsec.
    Therefore if there's something (at this moment in time, today, and we wait
    say 10 or 15 billion years for the light to reach us) is say 4.5 gigaparsecs
    away, it will appear to be moving away from us faster than the speed of
    light. This isn't due to its own actual motion, just the expansion of the
    space between us. However that light would be red shifted into oblivion
    before it could reach us.

    Does that make any sense?

    --
    Paul Smith,
    Yeovil, UK.
    http://www.dasmirnov.net/

    *Replace nospam with smirnov to reply by e-mail*



  6. #6
    Rodney Pont's Avatar
    Rodney Pont Guest

    Default The Age and Size of the Universe.

    On Sun, 04 Nov 2007 15:34:42 GMT, George Dingwall wrote:


    You're thinking of the speed of light as a limit and at creation time
    it wasn't because the physical laws didn't exist until after the
    creation bang. Is the first few tiny tiny bits of a second if expanded
    at a fantastic rate to nearly the size it is now. Then the Universe
    realised it existed and the physical laws came into effect and
    expansion continued at a similar rate to today. At least that's my
    understanding of what I read about it. I can't remember the title of
    the book now but something like 'The Seven Ages of the Universe'.

    The 13.7 billion light years that we can see are just the size of our
    raisin that we are in the centre of somewhere in a giant Christmas pud
    :-)

    --
    Regards - Rodney Pont
    The from address exists but is mostly dumped,
    please send any emails to the address below
    e-mail ngpsm4 (at) infohitsystems (dot) ltd (dot) uk



  7. #7
    Iordani's Avatar
    Iordani Guest

    Default The Age and Size of the Universe.

    George Dingwall wrote:


    I think it's wrong to see it as "occupying a volume"
    At the time, this was the whole universe. There is nothing on
    the "outside", not then and not now.


    I also think "across" is a bad word to use for this. If you do, you will
    end up like me and think like; I can see backwards in time by looking
    out in all directions. The more powerful the telescope, the older the
    universe I can observe. So it's all like a big onion with the oldest layer
    being the outmost layer of the onion. And here I am in the middle, so
    this is the newest part (and the point of origin...). And the part
    biggest in volume is the oldest one. Hmmm... Clearly, this very "human"
    way to view things must be the wrong approach when looking at the universe.

    And no, I don't know of any right approaches, sorry. I'm only human


    I wouldn't bet on that.

    There are a lot of reading about this. Try googling for 'big
    bang' 'superinflation' 'theory of relativity' etc..

    Stephen Hawking's 'A Brief History of Time' is also good reading.




  8. #8
    Stewart Robert Hinsley's Avatar
    Stewart Robert Hinsley Guest

    Default The Age and Size of the Universe.

    In message <m2pri3dqsph48lrdvvbrdm7eern6df4lkr@4ax.com>, George Dingwall
    <george.gdingwall@virgin.net> writes

    The speed of light is a limit on the movement of (non-tachyonic) matter
    in space; however the expansion of space, which is not a movement of
    matter in space, is not limited by the speed of light. If you want to
    know more I think you have to study General Relativity.

    --
    Stewart Robert Hinsley

  9. #9
    home@away's Avatar
    home@away Guest

    Default The Age and Size of the Universe.

    The real problem lies in presentation. Was it a presenter or an astronomer that
    claimed the diameter of the universe was >150 billion LY? I suspect the
    former..... Or perhaps the figure was mis-heard?

    Either way, confusion is a part of understanding, here. Our concept of the
    'diameter' is not a real distance anyway. Imagine being able to witness the
    start: there are no dimensions that can be judged at that 'time'. Treat such
    figures with curiosity rather than gospel.

    L


    On Sun, 04 Nov 2007 12:12:01 GMT, George Dingwall <george.gdingwall@virgin.net>
    wrote:


  10. #10
    MichaelJP's Avatar
    MichaelJP Guest

    Default The Age and Size of the Universe.

    "George Dingwall" <george.gdingwall@virgin.net> wrote in message
    news:gcdri3lqqempjg2lq2f6rpdbr1gnd7kfkr@4ax.com...


    I wouldn't worry too much - it's worth remembering that these theories of
    cosmology and the origins of the universe are just that, i.e. only theories.

    It's not like in earlier simpler times when a scientist "discovered"
    something like the cellular structure of plants under a microscope.

    These sort of theories are constructs invented to explain and predict
    observable phenomena. Whether they actually represent "reality" is a moot
    point. Some would say it doesn't even matter, as long as we can calculate
    the simple stuff like how to get a spaceship to Mars.

    Where it breaks down is when we end up having to add terms in for things
    like "dark matter", which may or not exist but represents the admission that
    the mathematics don't work and we've had to fudge it somehow.

    It's a bit like when as kids we used to get teachers explaining that atoms
    are like miniature solar systems with electrons whizzing round the nucleus
    in orbits like tiny planets. They're not, but it helped to form a mental
    picture and put things into some sort of context. That's all we can hope
    for, I suppose.



 

 
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