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Black Holes / Big Bang

Duxwing

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http://en.wikipedia.org/wiki/Second_law_of_thermodynamics

"The second law of thermodynamics states that the entropy of an isolated system never decreases, because isolated systems spontaneously evolve toward thermodynamic equilibrium—the state of maximum entropy."

The universe is at thermodynamic equilibrium. Otherwise it wouldn't be the universe. An increase can't occur beyond the maximum. :pueh:

Reread the sentence: the entropy of a closed system never decreases, but rather increases with time.

Well put, defghi. The very typing of this post increases entropy, an event perfectly in line with the current understanding of thermodynamics.

-Duxwing
 

SpaceYeti

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http://en.wikipedia.org/wiki/Second_law_of_thermodynamics

"The second law of thermodynamics states that the entropy of an isolated system never decreases, because isolated systems spontaneously evolve toward thermodynamic equilibrium—the state of maximum entropy."

The universe is at thermodynamic equilibrium. Otherwise it wouldn't be the universe. An increase can't occur beyond the maximum. :pueh:
Yet the universe isn't in equilibrium, because it's doing work. So.... you're wrong.
 

Duxwing

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THD, might you mistakenly be referring to the law of conservation of energy and matter, which states that the amount of energy and matter in a closed system never changes, as the Second Law of Thermodynamics?

"But... the universe, being everything, cannot. Things inside can shift about willy nilly, but as the all encompassing closed system, the universe itself has a delta S of 0. It's at equilibrium, which does not prohibit localized, internal, disequilibrium."

Provided that you are not: In a closed system, phenomena of a net dS greater than or equal to zero occur whenever their activation energy is met. Empirically, we know that some reactions have a dS > 0 where dH < 0; therefore, the global dS > 0.

-Duxwing
 

John_Mann

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And what about the real time shift?
 
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Evolves toward equilibrium, not is at equilibrium. The universe is headed towards equilibrium, hence increasing entropy.

If we were at equilibrium, we would be experiencing the http://en.wikipedia.org/wiki/Heat_death_of_the_universe
Kelvin is over-rated.
Reread the sentence: the entropy of a closed system never decreases, but rather increases with time.
Yet the universe isn't in equilibrium, because it's doing work. So.... you're wrong.
The total sum (enthalpy) of all entropy and extropy in the universe =0. How hard is it?

"Nothing creates order! Ehrmahgawd!"

But really, equilibrium depends on the model of the universe in question. Equilibrium can exist in a state of constant motion if the size of the universe is static and its contents are the size of the universe +/-1. The point of origin within the obese Cheerio would be a -1.

*EDIT: Also, see this: http://www.intpforum.com/showthread.php?t=17321

And consider that the plane described here is the cross-section of the Cheerio.
 

SpaceYeti

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Kelvin is over-rated.


The total sum (enthalpy) of all entropy and extropy in the universe =0. How hard is it?

"Nothing creates order! Ehrmahgawd!"

But really, equilibrium depends on the model of the universe in question. Equilibrium can exist in a state of constant motion if the size of the universe is static and its contents are the size of the universe +/-1. The point of origin within the obese Cheerio would be a -1.

*EDIT: Also, see this: http://www.intpforum.com/showthread.php?t=17321

And consider that the plane described here is the cross-section of the Cheerio.

I know for a fact that the state of the universe is not finished entropy, because stars are still burning. QED. There's not really an argument to be made against this. It's futile. The universe is not in equilibrium. We know it.
 

redbaron

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redbaron

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It's true, though. If the universe were in equilibrium, no work would be getting done.

"It is rather presumptuous to speak of the entropy of a universe about which we still understand so little, and we wonder how one might define thermodynamic entropy for a universe and its major constituents that have never been in equilibrium in their entire existence." - Walter T. Grandy, physicist, author of textbooks and peer-reviewed papers on thermodynamics/entropy

Only a wannabe quasi-scientist could be so petulant as you are about things he doesn't have the faintest idea about.

Thing is, you're just arguing from surface-level understanding.* It's clear you haven't done any in-depth reading of peer-reviewed studies, as well as some of the (lengthy) books written by actual physicists who study these things.

If you really understood the context built around these sorts of arguments, along with all of the doubts and explanations of the shortcomings of the methodologies we currently use to develop our understanding of the universe...

* Which is why I can't stand when people link to Wikipedia in debates about scientific matters. Wikipedia is a fucking stupid reference in matters like this, because it starts with the premise that its initial premise is true - providing a summation of the concept, taken as an excerpt from the original source material and devoid of the original context. Context within which we find all of the doubts and shortcomings of the study - which are readily admitted by the scientists conducting them, in the interest of clarity and to avoid these sorts of debates and misconceptions in the first place.

Stating things like this in broad terms with finality, devoid of supporting context and expression of reasonable doubt is exactly what science isn't about.
 

defghi

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If the universe were in equilibrium, no work would be getting done.

"universe and its major constituents that have never been in equilibrium in their entire existence."- Walter T. Grandy, physicist, author of textbooks and peer-reviewed papers on thermodynamics/entropy

These two things seem to agree...

You are right, and I agree with your point here as well as your previous posts, but this was a semantic issue, and while none of this paints the complete picture, we can still differentiate between true statements and untrue ones. "The universe is in equilibrium" is of the untrue variety. If we can't say that is untrue, then we can't say whether anything is true or untrue, thus getting us absolutely nowhere- also a rather unscientific methodology.
 

SpaceYeti

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"It is rather presumptuous to speak of the entropy of a universe about which we still understand so little, and we wonder how one might define thermodynamic entropy for a universe and its major constituents that have never been in equilibrium in their entire existence." - Walter T. Grandy, physicist, author of textbooks and peer-reviewed papers on thermodynamics/entropy

Only a wannabe quasi-scientist could be so petulant as you are about things he doesn't have the faintest idea about.

Thing is, you're just arguing from surface-level understanding.* It's clear you haven't done any in-depth reading of peer-reviewed studies, as well as some of the (lengthy) books written by actual physicists who study these things.

If you really understood the context built around these sorts of arguments, along with all of the doubts and explanations of the shortcomings of the methodologies we currently use to develop our understanding of the universe...

* Which is why I can't stand when people link to Wikipedia in debates about scientific matters. Wikipedia is a fucking stupid reference in matters like this, because it starts with the premise that its initial premise is true - providing a summation of the concept, taken as an excerpt from the original source material and devoid of the original context. Context within which we find all of the doubts and shortcomings of the study - which are readily admitted by the scientists conducting them, in the interest of clarity and to avoid these sorts of debates and misconceptions in the first place.

Stating things like this in broad terms with finality, devoid of supporting context and expression of reasonable doubt is exactly what science isn't about.
So you're saying I'm incorrect? If so, could you elaborate on the point instead of making an argument from authority? If the universe is a closed system, then when would we say it has reached heat death, or maximum entropy? Would it be while stars are still around? Certainly not, granting a never ending expansion. If the universe does not collapse into itself in a big crunch, then all stars will burn out. It's inevitable.

Even in the Cheerio scenario, entropy still applies, it would simply take longer for all the stars to burn out because they keep getting recycled in the black/white hole. In this case, entropy would be the cessation of the black/white hole. Just like a bouncing ball never bounces as high as it fell from, the white end would be unable to throw the energy as far as it did on the last cycle... eventually losing it's power to push matter out the other side anymore and the whole thing either disappearing or simply becoming a super-massive black hole with no white side and all the other energy of the universe then burning out as above. The only real benefit is that this cheerio universe would be really likely to big crunch after that... if you call it a benefit.

Either way, the universe is not in equilibrium.

This is all assuming the universe is a closed system, obviously, but you haven't bothered making a case against me, so... what? I'm utterly ignorant until I'm a PhD? I'm wrong because I'm not a physicist? Maybe I'm wrong, sure. I'll admit it if you supply decent evidence counter to my understanding of physics, too. All you're doing is calling me ignorant in more words, though. If you're concerned about my lack of doubt, provide some. Put up or shut up.
 

Cherry Cola

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Redbaron: That seems like a mere resort to scepticism. The same could be a said of a number things no?
 

Montresor

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An appeal to authority is only fallacious if it misinterprets the actual consensus of the actual experts in the community and/or quotes them out of context...

In this case, it's hard to tell, but I think the point he is making (if you'll allow me to try, RB) is that we are presently unable to define this equilibrium thus unable to discuss it, especially as fact and truth, particularly by referencing something that is such a target for vandalism.

I formally propose that we informally adopt the fallacy of Wikipedia into our collective reasoning.

It's too easy to read a Wikipedia article, possibly misinterpret it, and feel informed on a subject.
 

Cherry Cola

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I formally propose that we informally adopt the fallacy of Wikipedia into our collective reasoning.

It's too easy to read a Wikipedia article, possibly misinterpret it, and feel informed on a subject.

Very true, I could be guilty of this. Honestly I don't know. Just got interested in physics again and now I'm trying to soak up some layman knowledge on it so that I have something to ruminate with later.
 

SpaceYeti

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An appeal to authority is only fallacious if it misinterprets the actual consensus of the actual experts in the community and/or quotes them out of context...

I think the fallacy applies here because it's ambiguous what the quoted text even means, what the expert is even saying such that it's applicable in the first place. I didn't feel like looking up a more appropriate fallacy, at any rate. It's a fallacious argument because he never states why I'm wrong, he goes on about how I'm not an expert. I agree I'm not an expert, but that doesn't mean I'm wrong.

In this case, it's hard to tell, but I think the point he is making (if you'll allow me to try, RB) is that we are presently unable to define this equilibrium thus unable to discuss it, especially as fact and truth, particularly by referencing something that is such a target for vandalism.
What makes us unable to define it? It is fact and truth that, if the universe is a closed system and it does not end in a big crunch, that it will suffer a heat death where there are no more stars because all star fuel gets used up. It's not an idea of my invention, it's stuff I've read in books and online and from physicists both directly (once, anyhow) and in videos. Further, it makes damned good sense.

The difference is that the proposed universe wouldn't suffer heat death through exclusively stars running out of fuel, but also the wearing down and eventual cease of functioning of the central black/white hole. After that central hub wears down and stops, though, it's normal heat death time. Of course, because the shape of the universe brings everything back to the central point, it's far more likely to big crunch, possibly before the heat death happens. This, then, would probably be a more applicable full-entropy state; the universe collapses into a singularity. Even then, though, the universe is not a singularity, and is thus not in that end-state.

This, I believe, is the point of contention. Other people, I think, do not believe the central hole would wear down. However, entropy would not allow it to continue forever. If we imagine the hole not as a black hole/white hole singularity duo thing, then we could pretend it's simply a narrow "area" with no singularity. Relatively narrow. It'd still be large enough to let a good chunk of the rotating universe through. However, then we're left, essentially, with the universe simply spinning upwards in the center and downwards at the sides. It's essentially the same model, but no physics mumbo jumbo quantum BS can be hand-waved in as an explanation for why it could continue indefinitely.

In this case, the condensed gravity of the center would slow down the momentum of passing universal matter such that it wouldn't rotate out as far on it's next pass even if the reduction in speed is minute. It would continually slow down and, eventually, stop. I see no reason why this wouldn't be the case just because we pop a black hole in there instead of a slim nexus of space. Indeed, the black hole would make the matter worse because all matter would pass through the same point and pull back with as much possible energy as the amount of mass in there at the time could, because it's so very close. In fact, it being matter, it couldn't escape the black hole... except for this silly white hole opposite which shoots everything back out, magically, which that hasn't been explained yet, but I've been accepting it for the sake of argument, so whatever.

I formally propose that we informally adopt the fallacy of Wikipedia into our collective reasoning.

It's too easy to read a Wikipedia article, possibly misinterpret it, and feel informed on a subject.

That's fine. Wikipedia physics articles are generally just stubs or go all the way and end up way over my head either way, so I don't really look at them much anyhow.
 

Polaris

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Very true, I could be guilty of this. Honestly I don't know. Just got interested in physics again and now I'm trying to soak up some layman knowledge on it so that I have something to ruminate with later.


The best book I have ever read on the subject is The Fabric of the Cosmos by Brian Greene. He explains highly complex theories in layman terms...although I would not say it is an easy read. The book is an absolute brick, but it is worth it. Just don't get exhausted by the middle of the book and put it away for a longer period of time because you'll have to re-read everything again if you want to continue reading.....:ahh:
 
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* Which is why I can't stand when people link to Wikipedia in debates about scientific matters. Wikipedia is a fucking stupid reference in matters like this, because it starts with the premise that its initial premise is true - providing a summation of the concept, taken as an excerpt from the original source material and devoid of the original context. Context within which we find all of the doubts and shortcomings of the study - which are readily admitted by the scientists conducting them, in the interest of clarity and to avoid these sorts of debates and misconceptions in the first place.

Stating things like this in broad terms with finality, devoid of supporting context and expression of reasonable doubt is exactly what science isn't about.
I haven't bothered you much itt yet... To be fair, the purpose of a wiki link is often to provide a base conceptual overview to those actually motivated enough to investigate a phenomenon on their own; citations, further peer-reviewed searches, etc.

It's especially convenient considering one can't easily transfer a physical book online that isn't an ebook. Odum's Ecological and General Systems, for example.
 

Hawkeye

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The OP (and perhaps others in this thread) may find this link of some interest.
 

Brontosaurie

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i'm not knowledgeable on the subject, but: isn't there a difference between system equilibrium and total entropy?

@THD, SpaceYeti, redbaron
 

s0cratus

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Big bang and Black Holes
Can Black Holes forbid to create the Big Bang ?
===========.
 

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SpaceYeti

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i'm not knowledgeable on the subject, but: isn't there a difference between system equilibrium and total entropy?

@THD, SpaceYeti, redbaron
Thermally speaking, no. Entropy is the equilibrium of heat energy.
 

just george

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Thermally speaking, no. Entropy is the equilibrium of heat energy.
If the universe is toroidal in shape, centered around a black hole, then wouldn't part of the universe that is expanding be in a state of expansion and increasing entropy, while the other side of the universe doing the opposite and contracting/becoming more organized?

Personally I don't believe in the big bang theory, since no one can satisfactorily explain what was around to go bang in the first place. The only way that makes sense is that it may have felt like a bang when everything came out of one side of the black hole in the middle of the toroid.

Big Bang Theory = good tv show, crap physics theory.
 

Hawkeye

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Big Bang Theory is a mediocre show at best.

Black holes are not holes, or black for that matter .
 

SpaceYeti

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If the universe is toroidal in shape, centered around a black hole, then wouldn't part of the universe that is expanding be in a state of expansion and increasing entropy, while the other side of the universe doing the opposite and contracting/becoming more organized?

The far, outer edge of the universe isn't even important. It's functioning is perfectly in line with technically possible. The part of the model which is contradicted by Thermodynamics is the part where all the mass is condensed into a black hole... and then spit back out the other side! I'm not saying that can't happen. However, I am saying that condensed matter pulls on other matter such that even if this is the case, the matter which falls into one side of the black hole will never be shot out as quickly/far as it was last time, causing the universe to shrink with each cycle and eventually collapse into the singularity entirely as the escape velocity eventually becomes insurmountable.

The only way for the system to last is for there to be some sort of magical anti-backwards gravity functioning on half of the black hole... but we have no reason to presume something like that is possible.

Personally I don't believe in the big bang theory, since no one can satisfactorily explain what was around to go bang in the first place. The only way that makes sense is that it may have felt like a bang when everything came out of one side of the black hole in the middle of the toroid.
One of the cool things about science is that it doesn't matter waht Jack-ass Armchair-philosopher A thinks of it. Publish your refutation in respected scientific journals or shut your face. You either have a good argument against it or you don't. You don't. Your ignorance =/= a good argument against a valid scientific theory.

I've been over the whole "Time didn't exist before time such that 'before the big bang' is even a logically valid concept" thing before. It's not exactly difficult, either. Time started during the big bang. There's no such thing as "before" time. Difficulty understanding that doesn't mean you're more informed on the topic than most cosmologists on the planet such that you have any grounds to refute their theory.

Big Bang Theory = good tv show, crap physics theory.
I'm actually not that big a fan of Big Bang Theory. It's entertaining, but not worth setting a timer on my outdated VHS.

Haha, VHS.
 

just george

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The far, outer edge of the universe isn't even important. It's functioning is perfectly in line with technically possible. The part of the model which is contradicted by Thermodynamics is the part where all the mass is condensed into a black hole... and then spit back out the other side! I'm not saying that can't happen. However, I am saying that condensed matter pulls on other matter such that even if this is the case, the matter which falls into one side of the black hole will never be shot out as quickly/far as it was last time, causing the universe to shrink with each cycle and eventually collapse into the singularity entirely as the escape velocity eventually becomes insurmountable.

Hang on, why wouldn't what is going on at the edge of the universe be important? Wouldn't what is happening everywhere be important?

Also, have you ever bent your thought towards what comes out of black holes? Everyone says "nothing comes out of black holes" but...doesn't gravity come out? And doesn't gravity do some strange things to matter?


The only way for the system to last is for there to be some sort of magical anti-backwards gravity functioning on half of the black hole... but we have no reason to presume something like that is possible.
Actually we do. When atoms are monoatomic, they become superconductive, and then according to their heat, either become much heavier than usual or float.

Therefore, gravity doesn't interact with matter in the simplistic way Newton came up with. It seems to change as the spin of the atoms change.

One of the cool things about science is that it doesn't matter waht Jack-ass Armchair-philosopher A thinks of it. Publish your refutation in respected scientific journals or shut your face. You either have a good argument against it or you don't. You don't. Your ignorance =/= a good argument against a valid scientific theory.

Listen here Mr Hostile, I'll publish when I'm good and ready. Plus I don't respect the clowns at the journals very much myself.

I've been over the whole "Time didn't exist before time such that 'before the big bang' is even a logically valid concept" thing before. It's not exactly difficult, either. Time started during the big bang. There's no such thing as "before" time. Difficulty understanding that doesn't mean you're more informed on the topic than most cosmologists on the planet such that you have any grounds to refute their theory.
Time started at the big bang. I see.

So before the big bang, there was no time, and no universe, but then out of 2 nothings came 2 somethings.

I dunno, but this theory kind of stinks. Two nothings dont make a something.

I'm actually not that big a fan of Big Bang Theory. It's entertaining, but not worth setting a timer on my outdated VHS.

Haha, VHS.

Timer? You mean you actually wait for them, episode by episode?

People still do that?

omg.
 
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