By our current best understanding of physics, the universe as a whole is not a closed system, because there's new energy being created everywhere all the time by the expansion of space. — Pfhorrest
The second law of thermodynamics is itself a time asymmetry.
So, could perhaps the second law of thermodynamics itself therefore be responsible for the creation of new energy via the expansion of space, which in turn undermines the effects of the second law on the universe as a whole? — Pfhorrest
there's new energy being created — Pfhorrest
I thought that according to the law of conservation of energy, that energy is neither created nor destroyed. — Wayfarer
Anyway, if I understand right through my sleep-addled brain, you're suggesting that it's not so much (as I was speculating) that maybe some law of preservation of free energy (/ some kind of equivalent symmetry) requires that more space and so energy be created to counteract the increase in entropy, but rather that the increase in space and so energy requires (or makes room for the possibility of) thermodynamic action to counteract the decrease in entropy. It's not things winding down that inflates space, but inflating space that keeps things wound up. — Pfhorrest
The thermodynamic arrow of time and the second law of thermodynamics are thought to be a consequence of the initial conditions in the early universe. Therefore, they ultimately result from the cosmological set-up.
Anyway, if I understand right through my sleep-addled brain, you're suggesting that it's not so much (as I was speculating) that maybe some law of preservation of free energy (/ some kind of equivalent symmetry) requires that more space and so energy be created to counteract the increase in entropy, but rather that the increase in space and so energy requires (or makes room for the possibility of) thermodynamic action to counteract the decrease in entropy. It's not things winding down that inflates space, but inflating space that keeps things wound up. — Pfhorrest
entropy does not decrease when space expands — SophistiCat
Not necessarily new. I'm not a physicist, but I am interested in the symmetry between Energy & Entropy. Apparently, the universe began with all the energy it would ever have. But energy is a shape-shifter, in that it is constantly changing form, from potential to kinetic, from energy to mass, and back again. The traditional list of energy forms -- chemical, electrical, radiant, mechanical, thermal and nuclear -- may need to be updated to accommodate "Dark Energy" and "Dark Matter". But the general rule seems to be : "conserve energy, because it doesn't grow on trees". Therefore, despite speculations about "continuous creation", or "exchanging energy between mini-verses in a multiverse, our world still remains a closed system. But it's a dynamic system, and cybernetic system. So, it's a slippery bar of soap, for physicists to pin down. :smile:By our current best understanding of physics, the universe as a whole is not a closed system, because there's new energy being created everywhere all the time by the expansion of space. . . . what the corresponding symmetry to conservation of free energy would be. — Pfhorrest
I imagined to myself a little thought experiment or visualization: a toy system consisting of two points on a line segment, so it would have a very simple 2D configuration space, with obvious (err... note on that later*) peaks and valleys of entropy in it giving an obvious entropic arrow of time. And then, to that model, I added a third variable, and so a third dimension to its configuration space: the size of the line segment. Because higher-entropy states would be available on larger line segments, the entropic arrow of time would naturally point down the dimension of the configuration space that represents the size of the line segment... — Pfhorrest
In other words, in a completely empty space, the entropic arrow of time will be toward a larger completely empty space. But if there's an even steeper entropy gradient in the other dimensions of the configuration space, thereabouts the entropic arrow of time will be angled further away from straight down the dimension of the configuration space representing a larger line segment: in other words, if there's any process that results in higher entropy faster than making more space, that will happen first. — Pfhorrest
There is exactly one state of the system where the two points are maximally far apart. There are increasingly more states of the system where the two points are increasingly closer together. The most common distance-apart for the two points to be, out of all the possible configurations of the system, is zero. — Pfhorrest
Can you draw this? I'm struggling to see why a line on a 2D configuration space would be well-served by a third dimension representing the size of the line segment. My best interpretation is that you're introducing some non-locality but I'm not sure. — Kenosha Kid
But yeah there are other ways: increase the temperature, reduce the number of particles, stir the system up. These usually require work. — Kenosha Kid
I'm not sure how you feel about that in light of the above. There may well be fewer macrostates where volume is maximised, but that doesn't mean fewer microstates. For two-particle systems this isn't necessarily important, since, on a line, there are really only a few microstates making up the macrostate of maximal separation (though I'm unclear why you think there is such a state). However for a macroscopic system, there are a huge number of such states, an exponential function of particle number. ({1, 2, 3, 4, ...}, {2, 1, 3, 4, ...}, {1, 3, 2, 4, ...} and so on.) — Kenosha Kid
Then let's imagine a system just like that, except that n itself -- the width of the image -- is also variable. There's still only the two white pixels in it, whose positions are also variable. — Pfhorrest
Stirring the system up sounds like it amounts to the same thing as spreading the particles around — Pfhorrest
if the universe ever got to a point where there's almost no way to increase entropy by moving existing energy around, we might start to see violations of conservation of energy too. — Pfhorrest
I'm just talking about the toy system of points on a line. Let's look at our variation on that, the 1-by-n bitmap with two white pixels on a black background. For the sake of illustration let's set n=8 for now. There are exactly two (I mistakenly said one before) states where the white pixels are separated by 6 black pixels: if we call the pixels A and B and represent black space with underscores, those are the states: — Pfhorrest
Again, I'm not qualified to comment on the mathematical or physical aspects of your proposed symmetrical relationship between Space & Time, or between Free Energy & Spatial Expansion. But, I am interested in the Philosophical and Cosmological implications of the proportional relationship between Energy and Entropy.As though the conserved quantity is not just energy per se, but free energy: so as some energy becomes unfree as entropy increases, there's a commensurate creation of new free energy to keep the total free energy constant, which new energy is added everywhere equally, manifesting as an expansion of space. — Pfhorrest
So I guess the question here is what is it you suspect thermodynamics fundamentally is when you're dealing with two particles in a tube? Because it can't be statistical and be demonstrated by your toy model*. — Kenosha Kid
But all that aside, I like the idea that expansion is a kind of quantum tunnelling of the entire universe to a larger version of the universe to increase entropy. That does make some sense. — Kenosha Kid
Noether's Theorem seems to be a special case of Maupertuis' Principle of Least Action. — Gnomon
If you know anything about Verlinde's entropic model of gravity though, I would be curious to hear how something like that might relate to this entropic model of expansion, if you'd care to pontificate on that. — Pfhorrest
It wasn't exactly a "claim", but just an observation. I don't know much about either theory. But after reading descriptions, the "principle" seemed to be more general in application than the "theorem". In any case, I concluded that the PLA would have the opposite effect from "efficiently" Increasing Entropy. Instead, it would tend to conserve available Energy, acting as a brake on the dissipating effects of energy decay -- the end result of which is the projected Heat Death of the universe.I don't see how you're getting that claim. I am both talking about the Principle of Least Action, and also talking about Noether's Theorem, but I don't see why you'd say one is a special case of the other. — Pfhorrest
An additional thought that just occurred to me: in a string-theoretic model that requires higher dimensions that are presumed to be just very small and undetectable, perhaps the reason why only three of them got large is because there is as yet insufficient entropic advantage to enlarging them compared to other things that could be happening, and perhaps in some circumstances it could become advantageous and therefore more likely to happen. — Pfhorrest
I just came across the term "phantom energy" which seems to be what you are talking about. If such inflationary energy actually existed, it would result in a sudden "Big Rip", which sounds more dramatic (and unpleasant) than the current projection of a "Big Sigh" during the prolonged "heat death" of the universe. This reminds me of Woody Allen's quip : "I'm not afraid of death, I just don't want to be there when it happens". :joke:So, could perhaps the second law of thermodynamics itself therefore be responsible for the creation of new energy via the expansion of space, which in turn undermines the effects of the second law on the universe as a whole? — Pfhorrest
My personal cosmology is just the opposite of maximizing Entropy. Instead, the universe seems to be gradually maximizing order and organization. But, since we are currently at the You Are Here mid-point (in the graphic of my last post about the Big Rip), the amount of order right now is roughly equal to the amount of disorder.And so a universe that began as literally just an empty set, a zero, one black pixel, evolved more dimensions, larger dimensions, and more and more complex structure, because that became the best way of increasing entropy. — Pfhorrest
I understand that you don't agree with my holistic & positive assessment of the direction of evolution. But how did you come-up with that Big Brother oxymoronic assertion? I assume you are thinking of Entropy as merely a mathematical description of the energy availability in a system. How can you equate "order" with "disorganization"? Is that how the world looks from a reductionist perspective?Instead, the universe seems to be gradually maximizing order and organization. — Gnomon
This makes no sense; in fact, it's contradictory. According to thermodynamics: order is DISorganization ... DISorder is organization. — 180 Proof
Just look in the mirror at the increasing disorder that's organizing you, Gnomon! From what you've written, it appears you profoundly misunderstand (or "metaphysically" deny) entropy. And btw, I'm not a "reductionist".Order indicates heat source. Disorder indicates heat sink. Order descreases as heat dissipates (disorganizes) and thereby increases disorder – information – until thermal equilibrium between source and sink is reached (organized). To the degree a thermodynamic system is open (or expands), equilibrium is slowed (postponed). Emergent dissipative subsystems / structures contribute locally to increasing global disorder.
Again, you seem to be talking nonsense : "disorder that organizes". That paradoxical notion goes right over my pointy little head. It sounds like the "emptiness of space that is full of energy" in the quote below.Just look in the mirror at the increasing disorder that's organizing you, Gnomon! From what you've written, it appears you profoundly misunderstand (or "metaphysically" deny) entropy. And btw, I'm not a "reductionist". — 180 Proof
But an expanding universe is constantly non-equilibrium: it's essentially creating more and more possible configurations of matter that are each more likely than the one we're in. — Kenosha Kid
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