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Author Topic:   Big Rip theory
Chiroptera
Inactive Member


Message 16 of 40 (291218)
03-01-2006 1:31 PM
Reply to: Message 15 by kallcium
03-01-2006 12:59 PM


It may be that you are trying to make a point, but that I do not understand what your point is.
Here is a description of Big Bang:
It is observed that the galaxies are moving apart. The further away the galaxies are, the faster they are moving from us. The simplest explanation is that the universe (space itself) is expanding and carrying the galaxies apart. In fact, unless it is carefully doctored (with the addition of the so-called "csomological constant"), General Relativity itself says that the universe must be expanding or contraction.
So, looking backwards, everything in the universe must have been closer together. According to the laws of physics, the universe must have been hotter as well. So, the universe, as we look further back in time, must have been hotter and denser.
As we go further back in time, the universe must have been too hot and dense for stars or planets to exist, and, in fact, further back in time it must have been too hot and dense for atoms or even protons and neutrons to exist.
If we extrapolate further back in time, we get to a point where the universe is infinitely hot and dense -- the so-called singularity, beyond which we cannot push our understanding because our laws of physics cannot handle these kinds of infinites. However, we cannot even approach this singularity, since as we push backwards in time, the universe becomes so hot and dense that our current understanding of physics is inadequate to deal with it. Scientists are working on new theories to push further back, but for now we can only speak of the universe so far back in time.
So, the universe was once very hot and dense. The universe is expanding, and as it expanded it became cooler and less dense. This is pretty much Big Bang. Note that there is nothing about "explosions".
Notice that these observations about an accelerated expansion do not change any of this in any significant way. According to the Big Bang model, the universe is expanding; this accelerated expansion just says that the rate of expansion is not what we thought it was. According to Big Bang, in the past the universe was very hot and very dense. These ideas of dark energy do not change that, either; even taking into account this dark energy (which is only a way of describing the accelerated expansion of the universe), we still believe that the universe was hot and dense in the past.

"Intellectually, scientifically, even artistically, fundamentalism -- biblical literalism -- is a road to nowhere, because it insists on fidelity to revealed truths that are not true." -- Katha Pollitt

This message is a reply to:
 Message 15 by kallcium, posted 03-01-2006 12:59 PM kallcium has replied

Replies to this message:
 Message 17 by kallcium, posted 03-01-2006 1:39 PM Chiroptera has replied

  
kallcium
Member (Idle past 5462 days)
Posts: 26
Joined: 02-28-2006


Message 17 of 40 (291220)
03-01-2006 1:39 PM
Reply to: Message 16 by Chiroptera
03-01-2006 1:31 PM


Honestly how can the universe be infinatly hot and dense at one point? There has to be a finite point to that. If it were infinitly hot and dense then today there would be an infinate amount of energy (heat is energy) which there is not as stated by the laws of thermodynamics. If it were infintly dense then there would be an infanite amount of matter to keep making it denser, which there is not. There is a finite amount or energy and matter. Matter and energy can not be created nor destroyed. If you believe the universe was at one point infinately dense and hot, then came to a point in time in which it became a finte amount of heat and density, well then that takes a whole lot of faith.

This message is a reply to:
 Message 16 by Chiroptera, posted 03-01-2006 1:31 PM Chiroptera has replied

Replies to this message:
 Message 19 by Son Goku, posted 03-01-2006 1:50 PM kallcium has not replied
 Message 21 by Chiroptera, posted 03-01-2006 1:54 PM kallcium has not replied
 Message 28 by Modulous, posted 03-01-2006 3:31 PM kallcium has not replied

  
mark24
Member (Idle past 5195 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 18 of 40 (291226)
03-01-2006 1:49 PM
Reply to: Message 12 by kallcium
03-01-2006 12:54 PM


kallcium,
So in my conclusion, for me it takes faith to believe that God made the universe and caused it to accelerate the way it is, just is it requires an "equal and oppisite" faith the the big bang took care of that with the help of dark matter.
Actually, this isn't true. Your position requires the invention of a supreme being which we are expected to believe existed forever. This is a far less parsimonious explanation than not having a divine explanation. So, no, it is not an "equal & opposite" level of faith.
Mark

There are 10 kinds of people in this world; those that understand binary, & those that don't

This message is a reply to:
 Message 12 by kallcium, posted 03-01-2006 12:54 PM kallcium has replied

Replies to this message:
 Message 20 by kallcium, posted 03-01-2006 1:53 PM mark24 has replied

  
Son Goku
Inactive Member


Message 19 of 40 (291227)
03-01-2006 1:50 PM
Reply to: Message 17 by kallcium
03-01-2006 1:39 PM


No, it is simply the case that concepts like heat and energy begin to break down at the Big Bang. So when we analyze it with such concepts we get nonsensical answers.

This message is a reply to:
 Message 17 by kallcium, posted 03-01-2006 1:39 PM kallcium has not replied

Replies to this message:
 Message 22 by Chiroptera, posted 03-01-2006 1:57 PM Son Goku has replied

  
kallcium
Member (Idle past 5462 days)
Posts: 26
Joined: 02-28-2006


Message 20 of 40 (291228)
03-01-2006 1:53 PM
Reply to: Message 18 by mark24
03-01-2006 1:49 PM


Yeah actually the therory about the big bang is I believe that matter is eternal. That takes as much faith to believe as there is a supreme being that is eternal.

This message is a reply to:
 Message 18 by mark24, posted 03-01-2006 1:49 PM mark24 has replied

Replies to this message:
 Message 23 by Chiroptera, posted 03-01-2006 1:59 PM kallcium has not replied
 Message 26 by mark24, posted 03-01-2006 2:11 PM kallcium has not replied

  
Chiroptera
Inactive Member


Message 21 of 40 (291229)
03-01-2006 1:54 PM
Reply to: Message 17 by kallcium
03-01-2006 1:39 PM


quote:
There has to be....
Be careful about exclaiming about what there has to be. If the advent of quantum mechanics and relativity theory has taught us anything, it is that the universe is a far stranger place than our intuition would indicate.
-
quote:
If it were infinitly hot and dense then today there would be an infinate amount of energy...
No, just that the present amount of energy once occupied a very small volume. The energy density would be infinite, but not the energy.
-
quote:
...(heat is energy) which there is not as stated by the laws of thermodynamics.
The laws of thermodynamics, like all the laws of physics, are descriptions of how the universe behaves based on the observations that we have made up to now. But the universe is not actually constrained to "obey" laws that we set up. Just like the universe does not obey Newton's "laws" of motion, future observations might show that the universe does not actually obey the laws of thermodynamics.
-
quote:
If you believe the universe was at one point infinately dense and hot....
Actually, since our current understanding of the laws of physics do not allow us to describe the universe near the alleged singularity, we do not know if there even was a singularity. It may be that once quantum mechanics and general relativity are reconciled we will see that there was no singularity.
And it may very well be that we will discover that the universe during this time when the universe was too hot and dense for our current understanding to describe had a very, very different history than we expect. Myself, I have philosophical reasons to hope that the history of the universe had no beginning -- that it has existed infinitely long ago in the past.

"Intellectually, scientifically, even artistically, fundamentalism -- biblical literalism -- is a road to nowhere, because it insists on fidelity to revealed truths that are not true." -- Katha Pollitt

This message is a reply to:
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Chiroptera
Inactive Member


Message 22 of 40 (291231)
03-01-2006 1:57 PM
Reply to: Message 19 by Son Goku
03-01-2006 1:50 PM


quote:
No, it is simply the case that concepts like heat and energy begin to break down at the Big Bang.
You mean that the concepts break down near the postulated singularity. "Big Bang" is the description of the history of the universe for its first several hundred years or so, and how that history determines what we see in the current universe.

"Intellectually, scientifically, even artistically, fundamentalism -- biblical literalism -- is a road to nowhere, because it insists on fidelity to revealed truths that are not true." -- Katha Pollitt

This message is a reply to:
 Message 19 by Son Goku, posted 03-01-2006 1:50 PM Son Goku has replied

Replies to this message:
 Message 24 by Son Goku, posted 03-01-2006 2:03 PM Chiroptera has replied

  
Chiroptera
Inactive Member


Message 23 of 40 (291232)
03-01-2006 1:59 PM
Reply to: Message 20 by kallcium
03-01-2006 1:53 PM


Kallcium, I have presented a brief description of what Big Bang is. Where is the implication that "matter is eternal"?

"Intellectually, scientifically, even artistically, fundamentalism -- biblical literalism -- is a road to nowhere, because it insists on fidelity to revealed truths that are not true." -- Katha Pollitt

This message is a reply to:
 Message 20 by kallcium, posted 03-01-2006 1:53 PM kallcium has not replied

  
Son Goku
Inactive Member


Message 24 of 40 (291234)
03-01-2006 2:03 PM
Reply to: Message 22 by Chiroptera
03-01-2006 1:57 PM


Sorry, yes. Slip of the tongue.

This message is a reply to:
 Message 22 by Chiroptera, posted 03-01-2006 1:57 PM Chiroptera has replied

Replies to this message:
 Message 27 by Chiroptera, posted 03-01-2006 2:12 PM Son Goku has not replied

  
Son Goku
Inactive Member


Message 25 of 40 (291237)
03-01-2006 2:09 PM


Viewpoint.
The Big Bang, as a theory of the early universe is viewed quite differently by physicists today than one might expect.
The singular event that the Big Bang retrodicts isn't of interest to most physicists as an explanation of the origin of things, but rather as point in spacetime where General Relativity gave over to Quantum Gravity.
Currently there are three main ways, from what I know*, of coming at this problem.
Quantum cosmology, String Theory and Loop Quantum Gravity.
So far there have been no conclusive results from any of them.
*I'm not that involved in Quantum Gravity, so there could be others that are considered important.

  
mark24
Member (Idle past 5195 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 26 of 40 (291238)
03-01-2006 2:11 PM
Reply to: Message 20 by kallcium
03-01-2006 1:53 PM


kallcium,
Yeah actually the therory about the big bang is I believe that matter is eternal. That takes as much faith to believe as there is a supreme being that is eternal.
The point is that it doesn't. Reread my last post.
Mark

There are 10 kinds of people in this world; those that understand binary, & those that don't

This message is a reply to:
 Message 20 by kallcium, posted 03-01-2006 1:53 PM kallcium has not replied

  
Chiroptera
Inactive Member


Message 27 of 40 (291239)
03-01-2006 2:12 PM
Reply to: Message 24 by Son Goku
03-01-2006 2:03 PM


Heh. I'm just trying to defuse the "Big Bang says the universe exploded from nothing" notion.

"Intellectually, scientifically, even artistically, fundamentalism -- biblical literalism -- is a road to nowhere, because it insists on fidelity to revealed truths that are not true." -- Katha Pollitt

This message is a reply to:
 Message 24 by Son Goku, posted 03-01-2006 2:03 PM Son Goku has not replied

  
Modulous
Member
Posts: 7801
From: Manchester, UK
Joined: 05-01-2005


Message 28 of 40 (291274)
03-01-2006 3:31 PM
Reply to: Message 17 by kallcium
03-01-2006 1:39 PM


Einstein
I think anybody that wants to understand the Big Bang should read cavediver's posts on the subject. One such post can be found here, which I will quote for your pleasure:
cavediver writes:
Now, if we put in an infinte uniform mass distribution (like dust scattered through empty space) we get a different solution. The idea is that this distribution mimics the universe on the largest scale. This solution describes space-time as a finite hyper-sphere that starts with zero size (and hence infinite density), expands to maximum, and then contracts back to zero size.
Shortly after General Relativity made this prediction, Hubble came along and formulated the Redshift Distance Law of galaxies which is consistent with the predictions of General Relativity. That is, General Relativity predicted the nature of the universes expansion (and its hotter and denser past), and Hubble discovered that the expansion part of it was right.
Later, the cosmic background radiation was measured, this time confirming the prediction that the universe was much hotter and denser in the past, viz. The Big Bang.

This message is a reply to:
 Message 17 by kallcium, posted 03-01-2006 1:39 PM kallcium has not replied

Replies to this message:
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Chiroptera
Inactive Member


Message 29 of 40 (291300)
03-01-2006 5:22 PM
Reply to: Message 28 by Modulous
03-01-2006 3:31 PM


Re: Einstein
quote:
Later, the cosmic background radiation was measured, this time confirming the prediction that the universe was much hotter and denser in the past, viz. The Big Bang.
And it also should be noted that the relative abundances of nucleotides (particularly 1H, 4He, 3He, 2H and 7Li) are consistent with the Big Bang model. I believe that certain parameters were adjusted to fit the observed abundances so this may not count as a prediction of Big Bang, but it would have been easy for the demiurge to have created these elements in abundances that are completely inconsistent with any reasonable Big Bang scenario.

"Intellectually, scientifically, even artistically, fundamentalism -- biblical literalism -- is a road to nowhere, because it insists on fidelity to revealed truths that are not true." -- Katha Pollitt

This message is a reply to:
 Message 28 by Modulous, posted 03-01-2006 3:31 PM Modulous has not replied

  
Fabric
Member (Idle past 5671 days)
Posts: 41
From: London, England
Joined: 02-27-2005


Message 30 of 40 (291320)
03-01-2006 6:43 PM


What i find interesting is if Energy can not be made or destroyed then where did all the Energy in the universe come from ... i know the big bang theory says there was a begining but dos'nt answer what was the cause....
i also know that just after the singularity it was just pure energy, nothing else, but i thought Energy can not be made ?? I like the idea of the universe having a begining though otherwise all the stars would have been burnt out by now if it was infinite...
im only a 24 year old laymen but i find these questions fasinating... for obvious reasons..
my question is this...
Could all you peeps please tell me your personal theories on how you think the Universe started & why.... im really looking foward to your anwser's...
thanks for your time

Replies to this message:
 Message 31 by Chiroptera, posted 03-01-2006 6:52 PM Fabric has not replied
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