| View previous topic :: View next topic |
| Author |
Message |
kmisho
Stochastic
Joined: 05 Dec 2005
Posts: 4632
Local time: 4:45 AM
Location: Richmond, Virginia USA
|
 Posted: Fri Apr 25, 2008 9:15 pm Post subject: |
  |
|
| josephpalazzo wrote: | | kmisho wrote: | | josephpalazzo wrote: | | kmisho wrote: | | josephpalazzo wrote: | | Cyclic Universe |
I used to like the idea, but I'm always forced to go where the evidence is, and the evidence is that there is no force that could close the univers to induce the crunch part of the cycle.
This is my main problem, show me the crunch. |
The crunch would happen in billions of years, so showing it to you is out of the question... 
OTOH, no one can show you the bang either. On a logical basis tho', the cyclic theory makes more sense than the Big Bang theory for the reasons that Steinhardt has enumerated. Secondly, if one looks at the math, it is even more convincing -- the mechanism invoked is the same as in the Higgs field in the Standard Model, the same as in the BCS theory in superconductivity and the same as used to understand Boson condensates. Therefore, Steinhardt makes a pretty good argument. |
All of this may be true. I'm not in a position to know. But still, what is going to stop the universe from expanding? |
That's because you're still thinking in terms of the Big Bang: what will stop the universe from expanding after that big "explosion"?
The cyclic model was inspired by string theory: that our three-dimensional world is a surface or a "brane" embedded in a space, with an extra spatial dimension, separated by a microscopic distance from a second similar brane. A weak, spring-like force holds the two branes together and causes them to smash into one another and bounce apart, at regular intervals. Each collision is another big bang that produces hot matter and radiation, which is what ultimately gives rise to galaxies, stars, and planets. This theory incorporates dark matter and dark energy in a natural way, which the BBT can't except by introducing them by hand. In CT, visible matter is produced on our brane, and invisible or dark matter is produced on the other brane, why we never see it. |
You're wrong, by the way, on how I'm thinking of it.
I don't even see the cycle in what you describe. Plus I am a recent deconvert of string theory altogether until something frickin comes of it.
_________________
K Michau
Now this religion happens to prevail/Until by that one it is overthrown/Because men dare not live with men alone/But always with another fairy tale.
al-Ma'arri, Syrian Poet, died 1057
You deny the existence of 999 alleged Gods. I merely deny one more - yours.
John MacKinnon Robertson, "Godism" 1896
"Never is a long time." Robert Fripp, 1998
Poetry, Art, Music |
|
| Back to top |
|
 |
|
|
|
Gettin' In Tune
Forum Master
Joined: 03 Aug 2007
Posts: 2464
Local time: 1:45 PM
|
| Posted: Fri Apr 25, 2008 9:29 pm Post subject: |
|
|
| CT theory makes more sense than Heat Death, or the idea that energy and matter gets recycled. Is Heat Death considered a viable possibility? Heat Death implies a beginning and an end. Wouldn't a beginning imply a cause? |
|
| Back to top |
|
|
kmisho
Stochastic
Joined: 05 Dec 2005
Posts: 4632
Local time: 4:45 AM
Location: Richmond, Virginia USA
|
| Posted: Fri Apr 25, 2008 9:41 pm Post subject: |
|
|
I could be confused by what "cyclical" means.
Heat death is not necessarily the end. There's Lee Smolin's flowering universe idea.
_________________
K Michau
Now this religion happens to prevail/Until by that one it is overthrown/Because men dare not live with men alone/But always with another fairy tale.
al-Ma'arri, Syrian Poet, died 1057
You deny the existence of 999 alleged Gods. I merely deny one more - yours.
John MacKinnon Robertson, "Godism" 1896
"Never is a long time." Robert Fripp, 1998
Poetry, Art, Music |
|
| Back to top |
|
|
josephpalazzo
Illusion Master
Joined: 30 Aug 2006
Posts: 8036
Local time: 1:45 PM
Location: D-brane
|
| Posted: Sat Apr 26, 2008 9:10 am Post subject: |
|
|
| Moloth wrote: | | josephpalazzo wrote: | | kmisho wrote: | | josephpalazzo wrote: | | kmisho wrote: | | josephpalazzo wrote: | | Cyclic Universe |
I used to like the idea, but I'm always forced to go where the evidence is, and the evidence is that there is no force that could close the univers to induce the crunch part of the cycle.
This is my main problem, show me the crunch. |
The crunch would happen in billions of years, so showing it to you is out of the question...
OTOH, no one can show you the bang either. On a logical basis tho', the cyclic theory makes more sense than the Big Bang theory for the reasons that Steinhardt has enumerated. Secondly, if one looks at the math, it is even more convincing -- the mechanism invoked is the same as in the Higgs field in the Standard Model, the same as in the BCS theory in superconductivity and the same as used to understand Boson condensates. Therefore, Steinhardt makes a pretty good argument. |
All of this may be true. I'm not in a position to know. But still, what is going to stop the universe from expanding? |
That's because you're still thinking in terms of the Big Bang: what will stop the universe from expanding after that big "explosion"?
The cyclic model was inspired by string theory: that our three-dimensional world is a surface or a "brane" embedded in a space, with an extra spatial dimension, separated by a microscopic distance from a second similar brane. A weak, spring-like force holds the two branes together and causes them to smash into one another and bounce apart, at regular intervals. Each collision is another big bang that produces hot matter and radiation, which is what ultimately gives rise to galaxies, stars, and planets. This theory incorporates dark matter and dark energy in a natural way, which the BBT can't except by introducing them by hand. In CT, visible matter is produced on our brane, and invisible or dark matter is produced on the other brane, why we never see it. |
i've always really, really liked brane theory...
i;m just curious as to whether or not it has any practicality beyond the conceptual. |
Right now, branes in higher dimension are part of the main idea behind why gravity is such a weak force. Perhaps this will lead us some day to the detection of gravity waves. Other than that, I don't see any practicality in the short term. In the long term, branes might lead us to a full theory that unites gravity with the other three fundamental forces -- the electromagnetic force, the weak and strong nuclear forces -- and a better understanding of cosmological theories -- the cyclic theory being the target one presently. Who knows, maybe this could lead us to wormholes and space traveling, which now is only part of science fiction!!! |
|
| Back to top |
|
|
josephpalazzo
Illusion Master
Joined: 30 Aug 2006
Posts: 8036
Local time: 1:45 PM
Location: D-brane
|
| Posted: Sat Apr 26, 2008 9:16 am Post subject: |
|
|
| kmisho wrote: |
I don't even see the cycle in what you describe. |
A weak, spring-like force holds the two branes together and causes them to smash into one another and bounce apart at regular intervals. |
|
| Back to top |
|
|
kmisho
Stochastic
Joined: 05 Dec 2005
Posts: 4632
Local time: 4:45 AM
Location: Richmond, Virginia USA
|
| Posted: Sat Apr 26, 2008 9:30 pm Post subject: |
|
|
| josephpalazzo wrote: | | kmisho wrote: |
I don't even see the cycle in what you describe. |
A weak, spring-like force holds the two branes together and causes them to smash into one another and bounce apart at regular intervals. |
But this can't in itself correspond to the idea of the previous iteration affecting the next. Think of striking a gong several times. Each strike is just a strike, that propogates and dies, then comes the next strike, unifluenced by the previous. You said something about the seeding of galaxies being influenced by the preceeding iteration. I don't see the connection.
_________________
K Michau
Now this religion happens to prevail/Until by that one it is overthrown/Because men dare not live with men alone/But always with another fairy tale.
al-Ma'arri, Syrian Poet, died 1057
You deny the existence of 999 alleged Gods. I merely deny one more - yours.
John MacKinnon Robertson, "Godism" 1896
"Never is a long time." Robert Fripp, 1998
Poetry, Art, Music |
|
| Back to top |
|
|
Moloth
Coin Operated Boy
Joined: 27 Aug 2003
Posts: 23063
Local time: 1:45 PM
Location: Warner Robins, GA
|
| Posted: Sat Apr 26, 2008 9:33 pm Post subject: |
|
|
| josephpalazzo wrote: | | Moloth wrote: | | josephpalazzo wrote: | | kmisho wrote: | | josephpalazzo wrote: | | kmisho wrote: | | josephpalazzo wrote: | | Cyclic Universe |
I used to like the idea, but I'm always forced to go where the evidence is, and the evidence is that there is no force that could close the univers to induce the crunch part of the cycle.
This is my main problem, show me the crunch. |
The crunch would happen in billions of years, so showing it to you is out of the question...
OTOH, no one can show you the bang either. On a logical basis tho', the cyclic theory makes more sense than the Big Bang theory for the reasons that Steinhardt has enumerated. Secondly, if one looks at the math, it is even more convincing -- the mechanism invoked is the same as in the Higgs field in the Standard Model, the same as in the BCS theory in superconductivity and the same as used to understand Boson condensates. Therefore, Steinhardt makes a pretty good argument. |
All of this may be true. I'm not in a position to know. But still, what is going to stop the universe from expanding? |
That's because you're still thinking in terms of the Big Bang: what will stop the universe from expanding after that big "explosion"?
The cyclic model was inspired by string theory: that our three-dimensional world is a surface or a "brane" embedded in a space, with an extra spatial dimension, separated by a microscopic distance from a second similar brane. A weak, spring-like force holds the two branes together and causes them to smash into one another and bounce apart, at regular intervals. Each collision is another big bang that produces hot matter and radiation, which is what ultimately gives rise to galaxies, stars, and planets. This theory incorporates dark matter and dark energy in a natural way, which the BBT can't except by introducing them by hand. In CT, visible matter is produced on our brane, and invisible or dark matter is produced on the other brane, why we never see it. |
i've always really, really liked brane theory...
i;m just curious as to whether or not it has any practicality beyond the conceptual. |
Right now, branes in higher dimension are part of the main idea behind why gravity is such a weak force. Perhaps this will lead us some day to the detection of gravity waves. Other than that, I don't see any practicality in the short term. In the long term, branes might lead us to a full theory that unites gravity with the other three fundamental forces -- the electromagnetic force, the weak and strong nuclear forces -- and a better understanding of cosmological theories -- the cyclic theory being the target one presently. Who knows, maybe this could lead us to wormholes and space traveling, which now is only part of science fiction!!! |
weak, but incredibly far reaching. Gravity is a strange thing, to be sure. i mean, WHY would matter bend space-time?
a GUT (Grand Unified Theory) would kick so much ass... i wonder if they'll have on in my lifetime.
_________________
-=The Believer is Happy; the Skeptic is Wise=-
www.Moloth.com
Last edited by Moloth on Tue Feb 30, 2026 13:61 am; edited 426 times in total |
|
| Back to top |
|
|
josephpalazzo
Illusion Master
Joined: 30 Aug 2006
Posts: 8036
Local time: 1:45 PM
Location: D-brane
|
| Posted: Sun Apr 27, 2008 8:34 am Post subject: |
|
|
| kmisho wrote: | | josephpalazzo wrote: | | kmisho wrote: |
I don't even see the cycle in what you describe. |
A weak, spring-like force holds the two branes together and causes them to smash into one another and bounce apart at regular intervals. |
But this can't in itself correspond to the idea of the previous iteration affecting the next. Think of striking a gong several times. Each strike is just a strike, that propogates and dies, then comes the next strike, unifluenced by the previous. You said something about the seeding of galaxies being influenced by the preceeding iteration. I don't see the connection. |
The nearest analogy would be a body resting on the ground, attached to a spring, itself attached to a wall. Compress the spring, then let go. The whole system will oscillate back and forth.
Now, replace the wall and the mass m by two branes in higher dimensions, and every time they collide, this represents the Big Bang, after which, the branes move apart, only to revert direction and move towards each other. This is a cyclic motion.
In c), the force accelerates the universe, the mass m in this analogy. In b), the net force is zero, but the universe is still coasting with some speed, after which it will start to decelerate. At b) the universe has reversed course. |
|
| Back to top |
|
|
Unbeliever
Forum Master
Joined: 11 Apr 2005
Posts: 2550
Local time: 11:45 AM
Location: The exact center of my observable universe
|
| Posted: Mon Apr 28, 2008 8:23 pm Post subject: |
|
|
| Gettin' In Tune wrote: | | I am not arguing from design or from Occam's razor. I am arguing from ignorance and curiosity. Did the universe have a cause or always existed? |
I think 'always' is a bit vague when talking about the universe. If something 'always' existed, then there must never have been a time when it did not exist. But if time itself emerged from the singularity simultaneously with space, enegy and matter, then there was never a time when the universe did not exist, so it could be said to have 'always' existed. If something always existed, there's no need to invoke a prior cause for its existence.
_________________
"True wisdom is less presuming than folly. The wise man doubteth often, and changeth his mind; the fool is obstinate, and doubteth not; he knoweth all things but his own ignorance."
Akhenaton?( c. B.P. 1575)
Science is a lighthouse,
Faith is the rocks below.
God Not Found - resources for atheist/agnostics
"the universe is under no obligation to be easy for us to comprehend."
moloth |
|
| Back to top |
|
|
BobSpence1
Moderator
Joined: 21 Jul 2005
Posts: 2022
Local time: 4:45 AM
Location: Brisbane, Australia.
|
| Posted: Sat May 03, 2008 6:57 pm Post subject: |
|
|
I think current evidence points to ever-accelerating expansion ie, a Big Rip rather than a Big Crunch, with ever more fragmented bits becoming separated and maybe maybe eventually triggering a new Big Bang. This would avoid the Entropy 'problem', since each fragment would have a tiny fraction of the entropy of the whole.
Regarding the First Cause argument, that doesn't work because of if you assume the Universe needs a 'cause' great enough to consciously 'create' it, you are faced with explaining God, and so on.
This is all based on the assumption that every thing needs an identifiable 'cause' that must be equal to or greater than itself, leading to an infinite regression.
Once you realise that a given event does NOT require to be initiated by any discrete thing thing greater than itself, then even an 'infinite' regression of cause-effect does not require an infinite amount of time or energy, since if 'cause' can be less than 'effect', then the cumulative sequence may still be finite, in the same way that the sum of an infinite sequence of decreasing terms can be finite:
1 + 1/2 + 1/4 + 1/8 + 1/16 + .... <for> = 2
So ultimately the 'first cause' need be nothing bigger than a quantum twitch...
_________________
"To a committed free-thinker, blasphemy is not a crime but a duty" - me
"I believe that when I die , I will rot" - Bertrand Russell
"Theology is now little more than a branch of human ignorance. Indeed, it is ignorance with wings." - Sam Harris
Favorite oxymorons:
Business ethics
Gospel truth
Rational supernaturalist |
|
| Back to top |
|
|
|
|
|
Profile
Log in to check your private messages
Log in
Live Video and Chat Room
Freethought Videos
FAQ
Search
Usergroups
Register
