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Nope, the original poster was correct. Total entropy always increases or remains constant in a closed (isolated) system: the surroundings are irrelevant here.
Frumious Bandersnatch: Actually it does depend on your definition of closed.
[original poster]: Entropy (disorder) always increases or remains constant in a closed system.
Lucaspa: Somewhat correct but not quite. For a system, the total entropy of the systems and its surroundings must increase.
DNAunion: Nope, the original poster was correct. Total entropy always increases or remains constant in a closed (isolated) system: the surroundings are irrelevant here.
DNAunion: No, there's no haggling over definitions here - what I said is correct.
Frumious Bandersnatch: However, while you are both correct it is irrelevant since evolution on earth occurs in an open system.
Yesterday at 06:38 PM DNAunion said this in Post #38
DNAunion: Nope, the original poster was correct. Total entropy always increases or remains constant in a closed (isolated) system: the surroundings are irrelevant here.
Yesterday at 08:47 PM Jase said this in Post #41
If the universe first existed at a point of singularity, 1) how could enough matter to create the universe exist at a single point, and 2) where did the energy come from to set off the Big Bang? At a singular point, there is no net movement of matter, or it wouldn't be singular. So what gave the matter the energy to explode and bring forth more matter than was present to create the universe?
Lucaspa [quoting material]: "The combination of the system and its surroundings correspond to an "isolated system", as suggested in Fig. 7.4, since the process being considered affects nothing outside of the system and its surroundings" pg 191-192.
Lucaspa: I have never seen your definition of "closed" system in any thermodynamics text.
Thermodynamic Systems
A thermodynamic system is that part of the universe that is under consideration. A real or imaginary boundary separates the system from the rest of the universe, which is referred to as the surroundings. Often thermodynamic systems are characterized by the nature of this boundary as follows:
Isolated systems are completely isolated from their surroundings. Neither heat nor matter can be exchanged between the system and the surroundings. An example of an isolated system would be an insulated container, such as an insulated gas cylinder. (In reality, a system can never be absolutely isolated from its environment, because there is always at least some slight coupling, even if only via minimal gravitational attraction).
Closed systems are separated from the surroundings by an impermeable barrier. Heat can be exchanged between the system and the surroundings, but matter cannot. A greenhouse is an example of a closed system.
Open systems can exchange both heat and matter with their surroundings. Portions of the boundary between the open system and its surroundings may be impermeable and/or adiabatic, however at least part of this boundary is subject to heat and mass exchange with the surroundings. The ocean would be an example of an open system.
(http://www.wikipedia.org/wiki/Thermodynamics)
Types of Systems
Open System: A system that can exchange both matter and energy with the surroundings
Closed System: A system that can exchange energy, but not matter with the surroundings
Isolated System: A system that cannot exchange either matter or energy with the surroundings
(http://www.ncusd203.org/north/depts/science/chem/marek/apintropage/ap_notes/chapter7/chapter7.htm)
Isolated, closed and open systems. Isolated systems are ones in which no energy or matter is exchanged with the outside. For all intents and purposes this means the known universe. A closed system is one, which can exchange energy but not matter, and an open system can exchange both energy and matter.
(http://www.biochem.usyd.edu.au/~gareth/BCHM2001/mguss/lecture7.html)
"A precise statement of this idea is known as the second law of thermodynamics. It states that the entropy of an isolated system always increases, and that when two systems are joined together, the entropy of the combined system is greater than the sum of the entropies of the individual systems. (emphasis added, Stephen Hawking, The Illustrated A Brief History of Time: Updated and Expanded Edition, Bantom Books, 1996, p130)
Entropy: A measure of the amount of disorder in the Universe, or the availability of energy to do work. As energy is degraded into heat, it is less able to do work, and the amount of disorder in the Universe increases. This corresponds to an increase in entropy. In a closed system, entropy never decreases, so the Universe as a whole is slowly dying. In an open system, (for example, a growing flower), entropy can decrease and order can increase, but only at the expense of a decrease in
order and an increase in entropy somewhere else (in this case, in the Sun, which is supplying the energy that the plant feeds off). (Q is for Quantum: An Encyclopedia of Particle Physics, John Gribbin, Free Press, 1998, p126)
The explanation that is usually given as to why we dont see broken cups gathering themselves together off the floor and jumping back onto the table is that it is forbidden by the second law of thermodynamics. This says that in any closed system disorder, or entropy, always increases with time." (bold added, Stephen Hawking, The Illustrated A Brief History of Time: Updated and Expanded Edition, Bantom Books, 1996, p184)
Let us assume that one of the central principles governing Nature, the second law of thermodynamics, which tells us that the total entropy (disorder) of a closed system can never decrease, governs the evolution from cycle to cycle [of a continually rebounding universe]. (bold added, John D. Barrow, The Book of Nothing: Vacuums, Voids, and the Latest Ideas about the Origins of the Universe, Pantheon Books, 2000, p292-293)
Yesterday at 06:38 PM DNAunion said this in Post #38
DNAunion: Nope, the original poster was correct. Total entropy always increases or remains constant in a closed (isolated) system: the surroundings are irrelevant here.
Entropy (disorder) always increases or remains constant in a closed system.
Frumious Bandersnatch: [Lucaspa and DNAunion] almost seem to be making a deliberate effort to misunderstand each other here.
Fruminous Bandersnatch: A note to DNAunion: When you write closed(isolated) system as you have , I think you may be adding to the confusion a bit.
Frumious Bandersnatch: If you are going to call a closed system isolated you should specify that it is adiabatically closed especially when you give the standard definition of a closed system, that is not isolated in a subsequent.
Today at 09:20 PM Frumious Bandersnatch said this in Post #56
Let me try to explain again and perhaps clear up the confusion if I can.
This statement is only correct because he said he was talking about an adiabatically closed system in the preceding paragraph. Read without this qualifier the statement is not correct. I assume that this is the source of the misunderstanding. I thought badfish was wrong when I saw the statement at a first glance but then I saw that he said adiabatically closed so the statment is correct since it is obvious that he meant the adibatically closed system he had just referred to above.
...
Hope this helps. Maybe I wasn't too clear the first time. (Maybe not this time either but that's about the best I can do.)
The slightly frazzled Frumious Bandersnatch
Today at 10:11 PM DNAunion said this in Post #57
All I have to say is that a system is isolated - period. Saying it is isolated (1) makes it crystal clear what type of system I am disucssing, and (2) immediately shows that the surroudings are irrelevant to the changes in entropy that occur within that system.
Lucaspa [quoting material]: The combination of the system and its surroundings correspond to an "isolated system"...
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