Maximum entropy and expanding Universe

[Hacp]

So I don't really have a thorough grasp on what entropy is but this one thing doesn't make sense. I keep reading that there is a maximum entropy of the universe. However, if the universe is always expanding, then won't the entropy always increase by nkln(v2/v1)?

I'm not even sure you can apply that equation since you use it whenall potentials are at equilibrium and if the universe is continually expanding, you won't rever each equilibrium. Am I missing something obvious? Thanks.

 

[William Gaatjes]

So I don't really have a thorough grasp on what entropy is but this one thing doesn't make sense. I keep reading that there is a maximum entropy of the universe. However, if the universe is always expanding, then won't the entropy always increase by nkln(v2/v1)?

I'm not even sure you can apply that equation since you use it whenall potentials are at equilibrium and if the universe is continually expanding, you won't rever each equilibrium. Am I missing something obvious? Thanks.

I myself find entropy a strange concept too. The only link i can create is the increase/ decrease in what is known as thermal vibration of atoms when thinking of entropy and the universe.

If i understand correctly it means the amount of possible different outcomes when using a certain amount of variables. The word entropy sounds way to fancy, maybe i am wrong.

 

[f4phantom2500]

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

 

[Hacp]

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

That really doesn't answer anything. I already looked at the page and the only thing that was related was this entropy gap thing. That still contradicts the "maximum entropy" number that scientists have been looking for.

 

[f4phantom2500]

That really doesn't answer anything. I already looked at the page and the only thing that was related was this entropy gap thing. That still contradicts the "maximum entropy" number that scientists have been looking for.

dark energy keeps "pushing" the universe outward, forcing the continuing expansion set in motion by the big bang. something like 75% of the universe is composed of dark energy, and it appears that, as time goes on, more and more dark energy shows up; it's as if the universe is "impregnated" with it. while dark energy pushes the universe outward, dark matter pulls it together. dark matter composes about 20% of the universe, and visible matter composes about the other 5%.

the reason i posted the link to that wiki article was most specifically the section about heat death. the idea is that, as the universe eventually works its way toward maximum entropy, all of the potential energy in the universe will be expended, all reactions will eventually happen, resulting in an effective "death" of the universe, as it were. of course, it's just a theory.

at least, that's my understanding.

 

[Hacp]

dark energy keeps "pushing" the universe outward, forcing the continuing expansion set in motion by the big bang. something like 75% of the universe is composed of dark energy, and it appears that, as time goes on, more and more dark energy shows up; it's as if the universe is "impregnated" with it. while dark energy pushes the universe outward, dark matter pulls it together. dark matter composes about 20% of the universe, and visible matter composes about the other 5%.

the reason i posted the link to that wiki article was most specifically the section about heat death. the idea is that, as the universe eventually works its way toward maximum entropy, all of the potential energy in the universe will be expended, all reactions will eventually happen, resulting in an effective "death" of the universe, as it were. of course, it's just a theory.

at least, that's my understanding.

If the universe is to constantly expand, then there will always be a gradient and entropy will increase won't it?

 

[William Gaatjes]

I highly doubt the existence of dark matter and dark energy.

Come to think of it, heat energy can be influenced by electric and magnetic energy and gravity but it is not related. All separate forces but affected by each other.

Gravity.
Electric.
Magnetic.
Thermal.

When do these forces start to affect each other ?
And that is just what is known...

For some reason, in the traditional view of the universe the electric and the magnetic force do not seem to be a part of the universe. Only gravity and heat. All play their part. But when i ask questions of this to "educated" people, i get answers that let me think that these people actually think that electric and magnetic energy are free, a perpetual mobile : Free energy. Yeah right. Not in this universe. Not even there where the universe started energy was for free. For lack of a better description : self organization after the seed...

 

[CitanUzuki]

^^^
either

1. You aren't speaking to people who are "educated" enough to know.

OR

2. You are drawing the wrong conclusion from their response.

 

[A_Dying_Wren]

If the universe is to constantly expand, then there will always be a gradient and entropy will increase won't it?

It probably is just a case of approaching a maximum as opposed to actually reacting a mathematical maximum. The point is however that the universe will eventually become almost completely uniform but perhaps not absolutely completely.

^^^
either

1. You aren't speaking to people who are "educated" enough to know.

OR

2. You are drawing the wrong conclusion from their response.

Tis wise to either ignore william or point him in a right direction in case it gets to his head that he's either come up with a whole new theory that legions of scientists have never realized or thought on a particular tangent that, again, legions of scientists have never thought.

 

[Kyanzes]

The confusion could stem from a misinterpretation. In my understanding the universe is at maximum entropy *at all times*. The universe, say, a billion years ago was at maximum entropy and it will be at maximum entropy, say, a billion years from now as well.

Ofc I could be wrong in my own interpretation but that's how I understand it.

 

[Hacp]

The confusion could stem from a misinterpretation. In my understanding the universe is at maximum entropy *at all times*. The universe, say, a billion years ago was at maximum entropy and it will be at maximum entropy, say, a billion years from now as well.

Ofc I could be wrong in my own interpretation but that's how I understand it.

Ahk? Wtf? How is this possible?

 

[Kyanzes]

Ahk? Wtf? How is this possible?

I'm still suspecting a misinterpretation (and, again, it could very well be me).

The universe is at maximum entropy at all times as allowed (or described) by the second law of thermodynamics. You seem to be comparing former states to earlier or later states.

I think maximum entropy refers to "the maximum entropy possible" at the time. So it's not about comparison of various states at different times.

 

[Hacp]

I'm still suspecting a misinterpretation (and, again, it could very well be me).

The universe is at maximum entropy at all times as allowed (or described) by the second law of thermodynamics. You seem to be comparing former states to earlier or later states.

I think maximum entropy refers to "the maximum entropy possible" at the time. So it's not about comparison of various states at different times.

I still don't understand what you mean by this.I have never taken an astronomy course so I wouldn't know what astronomers define maximum entropy as.

Can you clear up what you mean by maximum entropy possible at the time? By "maximum entropy possible" do you mean maximum entropy at eventual equilibrium? Or do you mean total current entropy right now? In both cases there will be a new maximum a second later if the universe is really expanding.

 

[A_Dying_Wren]

I'm still suspecting a misinterpretation (and, again, it could very well be me).

The universe is at maximum entropy at all times as allowed (or described) by the second law of thermodynamics. You seem to be comparing former states to earlier or later states.

I think maximum entropy refers to "the maximum entropy possible" at the time. So it's not about comparison of various states at different times.

Its the change in entropy that the second law of thermodynamics refers to. Entropy will tend to approach a maximum in a closed system. A clear example is dissolving a substance in a solvent. Give it time and it will eventually dissolve and approach maximum entropy (maximum disorderliness). That's not to say however that maximum entropy is necessarily achieved nor of course that every moment reflects a maximum entropy state.

Of course in reality its difficult for there to be a truly closed system with the clear exception (theoretically at the moment) of the universe itself. This the universe will eventually tend to approach maximum entropy as a whole.

 

[William Gaatjes]

It probably is just a case of approaching a maximum as opposed to actually reacting a mathematical maximum. The point is however that the universe will eventually become almost completely uniform but perhaps not absolutely completely.



Tis wise to either ignore william or point him in a right direction in case it gets to his head that he's either come up with a whole new theory that legions of scientists have never realized or thought on a particular tangent that, again, legions of scientists have never thought.

At least i do not come up with negative time because my model does not work. And there is not going to be a higgs boson either. Well, there is after major modification of current models to make it fit together with a whole new range of particles and sub particles. Just as the negative time example. Poor Schrödinger.

 

[A_Dying_Wren]

At least i do not come up with negative time because my model does not work. And there is not going to be a higgs boson either. Well, there is after major modification of current models to make it fit together with a whole new range of particles and sub particles. Just as the negative time example. Poor Schrödinger.

Ah of course forgive me for forgetting: lest it gets to his head that he has single-handedly overturned various fields of science and devised models and theories of such brilliance no one except his enlightened self has theorized or understood it.

That's not saying there haven't been remarkable individuals who've done such amazing feats but I've seen scant evidence that our friend william here falls anywhere remotely near that category.

 

[neenasen]

How can maximum entropy be achieved if you say that the universe is infinite? Infinite means no ending!
If there is a beginning, then what is this beginning? Is it the beginning of time? Is the beginning when many, according to their religion, their Gods or God created the universe out of NOTHING?

Frankly speaking, this is a very touchy subject! In the history of science (not only Physics) and religion there were times when the two collided on a numbers of issues. Science tries to sort out things by getting the facts straight no matter how seemingly impossible it may be. However, religion claims based on their beliefs and on what their 'sacred writingg' and books' say. If it is something that can not be proven then just have faith and believe what religion tells and what their sacred writings say!. This is taking the easy way out.

 

[William Gaatjes]

Ah of course forgive me for forgetting: lest it gets to his head that he has single-handedly overturned various fields of science and devised models and theories of such brilliance no one except his enlightened self has theorized or understood it.

That's not saying there haven't been remarkable individuals who've done such amazing feats but I've seen scant evidence that our friend william here falls anywhere remotely near that category.

You are too kind, thank you very much but i am way to humble for that.
Besides, I would be crazy to let myself be turned into another example of a certain quote of Arthur Schopenhauer.

 

[f4phantom2500]

I highly doubt the existence of dark matter and dark energy.

Come to think of it, heat energy can be influenced by electric and magnetic energy and gravity but it is not related. All separate forces but affected by each other.

Gravity.
Electric.
Magnetic.
Thermal.

When do these forces start to affect each other ?
And that is just what is known...

For some reason, in the traditional view of the universe the electric and the magnetic force do not seem to be a part of the universe. Only gravity and heat. All play their part. But when i ask questions of this to "educated" people, i get answers that let me think that these people actually think that electric and magnetic energy are free, a perpetual mobile : Free energy. Yeah right. Not in this universe. Not even there where the universe started energy was for free. For lack of a better description : self organization after the seed...

http://news.nationalgeographic.com/news/2006/08/060822-dark-matter.html

also, the four (known) fundamental forces are gravity, electromagnetism (one force, not two), and the strong and weak nuclear forces. there is no "thermal force"; thermal energy is the result of a force or reaction.

EDIT: This article seems pretty interesting, I'm reading it right now.

http://www.stanford.edu/~alinde/1032226.pdf

 

[DominionSeraph]

If the universe is to constantly expand, then there will always be a gradient and entropy will increase won't it?

I think you're just looking at the baseline, not that things are still at equilibrium across the universe.
A universe at equilibrium doesn't allow for useful work to be done regardless of the temperature of the equilibrium.

A universe cooling due to increasing size doesn't allow you to pull heat from the hotter past into the future and do work across that boundary. That past heat is already present in that cooler future.

("Past present future" haha.)

That's my understanding, but I'm a 9th grade dropout self-taught in physics. If I'm wrong, just blame the teacher.

 

[William Gaatjes]

http://news.nationalgeographic.com/news/2006/08/060822-dark-matter.html

also, the four (known) fundamental forces are gravity, electromagnetism (one force, not two), and the strong and weak nuclear forces. there is no "thermal force"; thermal energy is the result of a force or reaction.

EDIT: This article seems pretty interesting, I'm reading it right now.

http://www.stanford.edu/~alinde/1032226.pdf

They are indeed tightly coupled. But my opinion is that those are not one force.

Thermal energy would indeed be a result not a cause. Sometimes i do write such things on purpose ^_^

When reading about the dark matter, how many millions or even thousands of years have these people been observing the collision of these galaxies ? Light takes time to travel. But light does not arrive all at once. How have they proven this existence of dark matter ?

 

[f4phantom2500]

They are indeed tightly coupled. But my opinion is that those are not one force.

Thermal energy would indeed be a result not a cause. Sometimes i do write such things on purpose ^_^

When reading about the dark matter, how many millions or even thousands of years have these people been observing the collision of these galaxies ? Light takes time to travel. But light does not arrive all at once. How have they proven this existence of dark matter ?

dark matter is simply a concept to explain the effects of gravity that have no visible cause (matter). it is "dark" in the sense that we can't detect or observe it directly, just the effects of gravity that "it" has on visible matter. as best i can tell, it's either dark matter or, for some yet known reason, gravity behaves much differently in those regions. i don't understand your point about light travel. are you suggesting that there are visible forms of matter exerting the gravity but that we can't see it yet because the light hasn't gotten here yet? that doesn't make sense because if it were that far away its gravity wouldn't have an effect on those regions of space that it does.

 

[William Gaatjes]

Ah of course forgive me for forgetting: lest it gets to his head that he has single-handedly overturned various fields of science and devised models and theories of such brilliance no one except his enlightened self has theorized or understood it.

That's not saying there haven't been remarkable individuals who've done such amazing feats but I've seen scant evidence that our friend william here falls anywhere remotely near that category.

Let me quote myself : what i had written 3 days ago :

At least i do not come up with negative time because my model does not work. And there is not going to be a higgs boson either. Well, there is after major modification of current models to make it fit together with a whole new range of particles and sub particles. Just as the negative time example. Poor Schrödinger.

And look what i read in the news today :

I already did write the same thing a year ago on this forum.
And 3 years ago mentioned the same thing to my colleagues.
It is not going to end. More and more particles will be found. All the same but measured and calculated differently.

http://www.physorg.com/news195885620.html

The Higgs was dubbed the "God particle" by Nobel laureate Leon Lederman because its discovery could unify our understanding of the universe and help us “know the mind of God”.

The Higgs is extremely important to the accepted theory of physics, known as the “Standard Model”, which was developed in the 1970s to incorporate everything known at the time about interactions between sub-atomic particles. The Higgs boson is thought to be the sub-atomic particle that mediates the force through which all other sub-atomic particles acquire their mass.

Scientists have been trying for five decades to detect the Higgs boson, but have so far failed. Now theoretical physicist Adam Martin and colleagues at the Fermilab’s Tevatron particle accelerator near Chicago in Illinois in the US have analyzed results from the DZero experiment and suggest there may be multiple versions of the Higgs boson.

The DZero experiment set up and observed collisions protons and anti-protons and was designed to examine the reason why the world is composed of normal matter rather than its opposite: anti-matter. They found the collisions resulted in pairs of muons one percent more often than anti-muon particles. The asymmetry could explain why matter has come to dominate over anti-matter, rather than the two annihilating each other.

This effect, called CP violation, had been seen before but not to the same degree as seen in DZero, and the degree of asymmetry found in the latest results is greater than can be accounted for by the Standard Model. The researchers said the results could be explained by the existence of five Higgs boson particles with similar masses, with one having a negative electric charge, one negative and three neutral. The theory is called the two-Higgs doublet model.

The two-Higgs doublet model is not the only possible explanation for the results, but Dr Martin said fitting a new effect in the Standard Model without disrupting its fit with other tests is difficult. The Standard Model accommodates only one Higgs doublet, and while scientists think of the Higgs as a single particle, Dr Martin said it “actually comes in a package of four”. Only one is seen because the other three are seen as W and Z bosons. Adding another Higgs doublet adds four more particles.

But it is just my opinion...
()

 

[Hacp]

Let me quote myself : what i had written 3 days ago :

But it is just my opinion...
()

Dear gates, I kinda want to get an answer to my question and It'll be hard to actually get an answer when all this unrelated bs is floating around.

 

[epidemis]

So I don't really have a thorough grasp on what entropy is but this one thing doesn't make sense. I keep reading that there is a maximum entropy of the universe. However, if the universe is always expanding, then won't the entropy always increase by nkln(v2/v1)?

I'm not even sure you can apply that equation since you use it whenall potentials are at equilibrium and if the universe is continually expanding, you won't rever each equilibrium. Am I missing something obvious? Thanks.

No, entropy won't increase.


Also read:
http://en.wikipedia.org/wiki/Metric_expansion_of_space