Notices
Results 1 to 11 of 11
Like Tree3Likes
  • 1 Post By Daecon
  • 1 Post By Daecon
  • 1 Post By Chrispen Evan

Thread: Dark energy and the expanding universe

  1. #1 Dark energy and the expanding universe 
    Forum Freshman
    Join Date
    Feb 2014
    Posts
    12
    Please forgive me if this sounds stupid.If dark energy is pushing the universe to expand at a accelerating rate and as it gets bigger the more dark energy exist to push the universe apart further and faster. Could this lead to light speed being broken as the stars are pushed away at speeds faster than light. Making the stars we see now disappear from view (or could it have already happened at lights source) Theoretically speaking? Or do I have a bad understanding of the theories involved?


    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Professor Daecon's Avatar
    Join Date
    Jul 2013
    Location
    New Zealand
    Posts
    1,288
    From how I understand it, it's not that galaxies are moving through space, it's that the space itself is expanding.

    To use the balloon analogy, draw dots on a balloon and blow it up, the dots move away from each other but they don't actually move through the rubber of the balloon surface. If that makes sense?

    Admittedly, I'm not an expert so I could be completely wrong, it's just how I think I understand it so far.


    Last edited by Daecon; February 17th, 2014 at 02:48 PM. Reason: typo
    Markus Hanke likes this.
    Reply With Quote  
     

  4. #3  
    Forum Freshman
    Join Date
    Feb 2014
    Posts
    12
    Or could the universe be a speck on a toroidal vortex expanding on the way to the outer edge of the vortex before it stops and contracts in to the centre?
    Reply With Quote  
     

  5. #4  
    Forum Freshman
    Join Date
    Feb 2014
    Posts
    12
    Daecon. I don't know. Would the dots not still be moving away from each other and away from the centre of the ballon to expand. I just trying to get a grasp, I must say I don't have a qualified understanding of all theories
    Reply With Quote  
     

  6. #5  
    Forum Professor Daecon's Avatar
    Join Date
    Jul 2013
    Location
    New Zealand
    Posts
    1,288
    Quote Originally Posted by ADD Dave View Post
    Or could the universe be a speck on a toroidal vortex expanding on the way to the outer edge of the vortex before it stops and contracts in to the centre?
    That sounds like the Big Crunch scenario, one of the possible ultimate fates of the Universe.

    Quote Originally Posted by ADD Dave View Post
    Daecon. I don't know. Would the dots not still be moving away from each other and away from the centre of the ballon to expand. I just trying to get a grasp, I must say I don't have a qualified understanding of all theories
    Well there's no real "center" of the balloon's surface (we're only using the rubber membrane as our analogy for the Universe, not the air inside the balloon). the idea is, if you go far enough in one direction you'll circle back around and end up in your original position.

    Even if the dots on the balloon (or the galaxies in the Universe) were moving away from each other faster than light speed, those galaxies are not actually moving through space - it's just the space in-between them expanding. I don't believe there's a theoretical limit as to how fast empty space can expand, only a limit as to how fast physical matter and energy can move through space.
    Markus Hanke likes this.
    Reply With Quote  
     

  7. #6  
    Forum Freshman
    Join Date
    Feb 2014
    Posts
    12
    Cheer cheer I think a get it. Does that mean that although the empty space between two points in the universe are expanding and the light would still have to travel these greater distances limited by the speed of light that eventually the stars as we see them will cease to shine. Or could the laws governing the speed of light be dynamic?
    Reply With Quote  
     

  8. #7  
    Forum Professor Daecon's Avatar
    Join Date
    Jul 2013
    Location
    New Zealand
    Posts
    1,288
    I think (not certain, will have to wait for an actual expert to respond) that the "inflation" stage at the beginings of the Universe was a brief period of time where space actually was expanding faster than light speed.

    Because of this, light/electromagnetic energy in one part of the Universe will never, ever be able to reach the region of another part of the Universe, and so you can conclude that these separate regions will never be able to interact with each other.

    I think (again not sure) that if space ever again expanded faster than light speed, distant stars would appear to redshift into nothingness instead of "blink" out.
    Reply With Quote  
     

  9. #8  
    Forum Senior
    Join Date
    Sep 2012
    Location
    Western Australia
    Posts
    319
    http://www.phinds.com/balloonanalogy/

    The Balloon Analogy is a simpleminded way to HELP describe (but not completely describe) two facts of cosmology that are difficult for many people to see, namely that the universe is expanding uniformly and that there is no center.

    The analogy is disliked (often intensely disliked) by serious physicists because it causes at least as much confusion as it is intended to avoid and is often badly misunderstood and/or incorrectly extrapolated to ridiculous points of view.

    Presented here is the simpleminded balloon analogy and then a discussion of cosmology and why the balloon analogy is so flawed. There are many other aspects of cosmology that can get drawn into discussions of the balloon analogy, but I have for the most part resisted discussing any that are not immediately relevant to the analogy, lest I get carpal tunnel syndrome while having this page turn into a textbook on cosmology (which I am not qualified to write anyway). I have given a couple of links at the bottom of the page to further discussions.

    more at link.
    dan hunter likes this.
    Sometimes it is better not knowing than having an answer that may be wrong.
    Reply With Quote  
     

  10. #9  
    New Member
    Join Date
    Feb 2014
    Location
    Bracknell, UK
    Posts
    1
    I thought one of the main foundations of the Expanding Universe theory is that the light (radiation) from objects moving away from us has redshift (z-) values, compared to our standard star's light. Because high redshift should indicate very distant objects the idea of quasars being extremely distant, faint objects arose. However there seems to be a problem with the assumption. Several astronomers have found groupings of objects which have a wide range of z-values. An example is the quasar (z=2.114) in front of NGC 7319 (z=0.0225). The late Halton Arp disputed accepted belief and considered red-shift may indicate the energetic emergence of daughter galaxies. Their brightness increases as their redshift reduces.
    Reply With Quote  
     

  11. #10  
    Forum Freshman
    Join Date
    Feb 2014
    Posts
    12
    Many thanks for all replies. Looked up redshift (left school @ 15). I'm processing but don't have much time to study ATM as I have to be up in 5 hours for another day. Will process info ASAP. Many thanks
    Reply With Quote  
     

  12. #11  
    Forum Bachelors Degree GoldenRatio's Avatar
    Join Date
    Dec 2013
    Posts
    415
    I disagree with others. I do not see the expansion of the universe having a limited speed of expansion. The speed of light could not be broken, however the amount of space that exists between two points could expand at such a rate where light would not reach from one to the other in the lotted amount of time.

    Strange, invisioning a civilization some 5 billion+ years in the future turning to the heavens and finding no galaxy's beyond there own. They will come to the wrong conclusion that the universe is void & have a skewed view of reality, simply because they are unable to see the light trying to overcome expansion to reach them. A universe that is no more than 100-200 million light years across.
    Reply With Quote  
     

Similar Threads

  1. Proof of contents ratio of the universe. Negative energy, Dark matter, Dark energy
    By icarus2 in forum Personal Theories & Alternative Ideas
    Replies: 8
    Last Post: October 22nd, 2013, 05:47 PM
  2. Replies: 4
    Last Post: October 22nd, 2013, 06:05 AM
  3. The universe is made of a particle, not dark energy
    By victorespinoza in forum Pseudoscience
    Replies: 3
    Last Post: August 29th, 2011, 01:24 PM
  4. Dark Energy or Variably Aged Universe?
    By War Arrow in forum Astronomy & Cosmology
    Replies: 8
    Last Post: October 28th, 2008, 09:05 AM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •