/sci/ - Science & Math

>>15623384
Fuck nigga iounno

>>15623384
Please define what you think "gravitational entropy" is.

>>15623408
The tendancy of things to come together.

>>15623410
That's just gravity...

>>15623384
Gimmie 5

>>15623417
Is it? My bad, what's gravitational entropy then?

>>15623417
The tendency of things to become more ordered? I suppose.

>>15623410
that is gravity
but
wouldn't this so-called entropy of gravitation be the inverse of this, or an inverse principle
i.e. the quantity of unadhered / unmassed matter in a system ?

>>15623430
Seems like a term you made up.
>>15623432
Matter attracting other matter doesn't mean it becomes more ordered.

>>15623408
>gravitational
Of gravity, related to attraction of gravitational source
>entropy
Quantified disorder, an attempt to assign a number to adjectives like "chaos" or "unknowable"

>>15623442
But matter does become more ordered. Is gravity not responsible for this?

>>15623449
okay.... so what does it mean when you combine those words into a term?
>>15623450
Why are assuming matter becomes more ordered when attracted to each other? It could a result in increased disorder or same amount of disordered.

>>15623450
no

>>15623450
Do you believe black holes have increased entropy or decreased entropy than the sum of the matter that was used to create it? Because it was created from gravitational forces.

>>15623457
>>15623458
So what do we cann the tendancy of things to become ordered?

>>15623450
>But matter does become more ordered
When two objects collide you think matter is becoming more ordered?

>>15623465
Well I've been told black holes are the largest sources of entropy, but I don't really understand why.

>>15623466
There isn't a tendency of matter on average becoming more ordered in a closed system.

>>15623468
Gravity does more then make objects collide, doesn't it?

>>15623442
What did you think of Katamari Damacy?

>>15623485
Fun game. Why?

>>15623466
go to a hospital you're having a stroke

There isn't? Then why is there so much apparent observed order?

>>15623488
Please be kind, this is supposed to be a blue board.

>>15623489
Retard, starlight itself is literally observable entropy.

>>15623493
What isn't entropy?

>>15623499
Lots of things

>>15623492
That was medical advice which is very kind.

This is what got me thinking, without knowing too much
>Max Planck wrote that the phrase "entropy of the universe" has no meaning because it admits of no accurate definition.[23][24] In 2008, Walter Grandy wrote: "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."[25] According to Tisza: "If an isolated system is not in equilibrium, we cannot associate an entropy with it."[26] Buchdahl writes of "the entirely unjustifiable assumption that the universe can be treated as a closed thermodynamic system".[27] According to Gallavotti: "... there is no universally accepted notion of entropy for systems out of equilibrium, even when in a stationary state."[28] Discussing the question of entropy for non-equilibrium states in general, Lieb and Yngvason express their opinion as follows: "Despite the fact that most physicists believe in such a nonequilibrium entropy, it has so far proved impossible to define it in a clearly satisfactory way."[29] In Landsberg's opinion: "The third misconception is that thermodynamics, and in particular, the concept of entropy, can without further enquiry be applied to the whole universe. ... These questions have a certain fascination, but the answers are speculations."[30]

>>15623505
What would you call the tendency that those things share?

>A 2010 analysis of entropy states, "The entropy of a general gravitational field is still not known", and "gravitational entropy is difficult to quantify." The analysis considers several possible assumptions that would be needed for estimates and suggests that the observable universe has more entropy than previously thought. This is because the analysis concludes that supermassive black holes are the largest contributor.[31] Lee Smolin goes further: "It has long been known that gravity is important for keeping the universe out of thermal equilibrium. Gravitationally bound systems have negative specific heat—that is, the velocities of their components increase when energy is removed. ... Such a system does not evolve toward a homogeneous equilibrium state. Instead it becomes increasingly structured and heterogeneous as it fragments into subsystems."[32] This point of view is also supported by the fact of a recent[when?] experimental discovery of a stable non-equilibrium steady state in a relatively simple closed system. It should be expected that an isolated system fragmented into subsystems does not necessarily come to thermodynamic equilibrium and remain in non-equilibrium steady state. Entropy will be transmitted from one subsystem to another, but its production will be zero, which does not contradict the second law of thermodynamics.[33][34]

>>15623457
gravitational entropy

>>15623384
Of course not. In your picture that black hole will evaporate into very low energy photons, useless to do work.

>>15623537
Why are they useless? Also how do we know they are going to evaporate? I've been told we don't have any evidence of Hawking radiation...

>>15623537
Forgot image
Captcha k420n

>>15623512
All things aside from entropy don't share one tendency.

>>15623531
Ok OK fine
To expand on this a bit, gravity creates order directly, eventually. I mean the rest, idk yet

>>15623598
>gravity creates order directly
no it doesn't

>>15623605
What creates order then?

>>15623616
Increased order is localized from external energy (such as the increased order from life on earth from energy from the sun).
In a large closed system, order decreases over time.

>>15623623
I've been told the universe is infinite in both time and space; that it is expanding in some places, and contracting in others.

>>15623623
So what is responsible for the order of the universe?

>>15623384
have you looked into entropic models of gravity?

also you may find it fun to think about a gravitational maxwell’s demon. suppose you had two wells, one deeper than the other, separated by a wall. they are under the influence of gravitation and have gases within them at equal temperature . with the proper well depths, a molecule with a given velocity (eg see Maxwell distribution for velocity), might have the ability to overcome the gravitational potential and traverse to the other side. since gravity is conservative, it will have the same amount of kinetic energy when it falls to the other side.

since a subset of the molecules on the side of the deeper well will be unable to cross over (they require higher kinetic energy), we will notice a net transfer of high velocity particles to one side. thus, a (non-fluctuation) temperature gradient will be produced with no added energy. what steps are required to resolve this with second law?

>>15623641
>>15623649
You have a flawed, limited understanding of astrophysics and you're using it to draw flawed conclusions.
I also have a limited understanding of astrophysics, but I don't use it to come to bizarrely specific, weird conclusions.

>>15623649
"Order" is just a relative term based on statistics.
From your replies, it seems you haven't looked into the actual math that describes changes in entropy.

>>15623657
You have been very helpful, thank you very much. I still have to assert my question, however.>>15623649

>>15623605
1 black hole is less things to count than the sum of what created it.

>>15623655
Checked, it doesn't seem weird to me

>>15623674
I don't think that's what entropy means though...

>>15623672
Your questions is nonsensical when talking about a relative term, order isn't "created" but is can increase and decrease relative to its previous state.
If your real question is: what causes a decrease in entropy (increased order), the answer is energy.

>>15623679
Underscore that black holes make photons which do nothing but evaporate it. Whatever bounds the a system had before the black hole was created are meaningless if a photon gets emitted. So the boundary of the system is redefined at this point only.

>>15623417
no, gravity isn't exclusive things coming together, what are orbits and spheres of influence you psued
>>15623430
>apologizing
dont let people gaslight you so easily, maybe lurk more

>>15623684
>Gravitationally bound systems have negative specific heat—that is, the velocities of their components increase when energy is removed. ... Such a system does not evolve toward a homogeneous equilibrium state. Instead it becomes increasingly structured and heterogeneous as it fragments into subsystems."
What does this mean? Doesn't it mean perpetual motion or something?

>>15623700
It's not a sign of weakness to admit fault or try to facilitate communication, eh?

>>15623700
Gravity is the weak force that causes large objects to attract each other.
Of course that force isn't always enough to overcome momentum, but its still the primary force that causes large objects to attract each other.

>>15623679
Well, what does it mean?

>>15623512
"Entropy" is whenever anything is in the process of losing energy. All radiation, electromagnetic or otherwise, is energy loss.

>>15623726
>>Max Planck wrote that the phrase "entropy of the universe" has no meaning because it admits of no accurate definition.

>>15623727
So what's the opposite of entropy?

>>15623732
Isn't that the guy that killed millions of people?

>>15623739
Oh shit, can I get a QRD?

>>15623744
Just look it up, what.

>>15623755
Just tell me how he did it I mean.

>>15623755
I googled did Max Planck kill millions of people and the results weren't the best

>>15623709
yeah it is on 4channel and you being so oblivious has me convinced youre GPT or ESL talking through google translate
>>15623717
and its has a net entropy when it works to stick matter together instead of just letting things weakly influence each other like what happens in most of the time.

a planet and I pulling each other isnt an example of gravitational entropy, but the accumulation of mass into a very large sphere, is

>>15623770
Did you try thousands?

>>15623773
How did he do it?

>>15623472
black holes smush everything together. Splitting atoms up into their subatomic parts and quarks is increasing entropy

>>15623784
>Splitting atoms up into their subatomic parts and quarks is increasing entropy
Wrong.

>>15623772
Are you from the United States by chance?

The universe will end due to star supernovae.

>>15623906
post hand.

>>15623777
I can't lie I don't think he did.

>>15624002
I don't want to make myself a target for any harrassment,

>>15624049
Can people tell where I am from that photo?

>>15624002
I posted it but then I got nervous and deleted it, why do you want to see my hand?

>>15623384
Gravitational entropy doesn't run opposite to heat entropy. Entropy is increasing in both top and bottom in your pic.

>>15625232
So what is the opposite of heat entropy?

>>15623649
jews

>>15623654
>what steps are required to resolve this with second law?
Dunno. Usually what happens is some scientists make up some crap for why free energy can't happen. It's like this all the time, cool things are not allowed.

>>15625431
I don't get it, but I'm really thinking about this now. What does humanity have to do with the beginning of the universe, if it did have a beginning.

>>15623654
Which one gets hotter? The deeper one, right?

>>15625232
What is entropy, even?

>>15625512
>the measure of a system's thermal energy per unit temperature that is unavailable for doing useful work.

>>15625232
>Gravitationally bound systems have negative specific heat—that is, the velocities of their components increase when energy is removed.

>>15623654
don't really get what you're saying. Is this what you mean? It doesn't work because we can't have nice things. There is no other reason.

>hay guise!!!
>i know everything about the entire universe!!

>>15625708
I didn't say that, I am just trying to get some clarification.

1

>>15625534
>that is, the velocities of their components increase when energy is removed.
That's not what negative specific heat means. The temperature decreases as mass enters the black hole but entropy increases (it scales with the area of the horizon). In any case not every gravitationally bound system is a black hole.

>>15623432
what if the universe is accelerating, and all the ancient aliens shit used to actually happen but doesn't anymore because they're too far away now

>>15627015
Light speed dictates we would be able to see them