Doc, I didn't suggest the Earth was a closed system. Dimensio observed that the "only" closed system we know of is the universe itself. And I asked how he knew this was a true statement: How do we know the universe is NOT exchanging energy with something else? Do we really know this for an absolute "fact"?
But we were originally speaking about abiogenesis. May we return to this contentious topic?
It appears that the probabilities of abiogenesis would be far greater if we had an open system with an energy source that maintains the system far from equilibrium. This presumably would avoid the setting in of the disorder that occurs pursuant to the Second Law in equilibrium processes.
The earth has a constant energy source in the Sun; but I have doubts that energy source alone is sufficient to support abiogenesis. It seems to me that, for abiogenesis to occur, the energy flow must have a mechanism whereby sufficient information content can be generated into inert matter. For living systems are such as they are by virtue of the information content they contain, which even in the most humble organisms is an enormous amount of specified instructions. Complexity of information content is said to be the principal characteristic of living matter.
It seems to me to know life's origin requires an explanation of the development of molecules with intense information content. But by what means does the energy flow keeping a system far from equilibirum generate information content? How does a mechanism that stores, transfers, and directs information arise spontaneously -- from balrog666's famous primaeval muck as it were? The sun can beat down on a mud puddle all day long, and still we would not see a living organism spring up as a result.
How can natural selection be a viable explanation for the origin of DNA and enzymes when natural selection does not exist in prebiological molecules? How did we get to "here" from "there?"
It seems that for life to begin, energy flow must be directed to produce information content in inert matter. This seems to be the fundamental problem of the origin of life, not the influence of the Second Law -- which has been so exhaustively studied in gasses. (Life is more than gasses.)
When I suggested that material systems are "closed," obviously I did not mean this in the same sense as Dimensio's definition. To me, any system lacking in intelligence is "closed."
This probably won't help you much, but here's an ancient quote I like a lot:
The world has a body that a man can see, and an intelligence that a man cannot see. And it takes both to make a living world.
FWIW. I'm having a busy work day, so must run for now. I'll try to come back latter. So much to do, so little time....
I noted before that the energy transferred from the sun to Venus is probably more than that transferred to the Earth.
The latter is almost certainly due to lava flows (which may still be going on). In sum, current best guess is that the composition of Venus is similar to that of Earth, though probably not identical to it. I got the above information from: "Exploration of the Universe" by Abell, Morrison, and Wolff; "The Solar System" by Encrenaz and Bibring; and "The Solar System" by B.W. Jones (you may need to go to a university library to find books like these).
What is known about the Venusian interior comes primarily from the Venera, Pioneer Venus and Magellan spacecraft. Before these explorers, scientists thought that Venus would have tectonic processes similar to that of Earth's mantle convection. Venus and Earth are both similar in size and presumable the same composition. However, Venus showed no sign of plate tectonism, and appears to have a single plate which makes it very different from Earth.
The atmosphere of Venus is mostly carbon dioxide, 96.5% by volume. Most of the remaining 3.5% is nitrogen. Early evidence pointed to the sulfuric acid content in the atmosphere, but we now know that that is a rather minor constituent of the atmosphere.
Plenty of carbon is available. Where the water went to is a question. But who says life necessarily needs water? Well where is the self-organization on Venus?
http://www.newton.dep.anl.gov/newton/askasci/1993/astron/AST052.HTM
http://www.solarviews.com/cap/venus/venusint.htm
http://hyperphysics.phy-astr.gsu.edu/hbase/solar/venusenv.html
"Information content" is a meaningless phrase in this context.
For living systems are such as they are by virtue of the information content they contain, which even in the most humble organisms is an enormous amount of specified instructions.
You mean that for currently extant organisms and include the complete arrangement of their DNA/RNA/whatever? So what?
Complexity of information content is said to be the principal characteristic of living matter.
Not by biologists.
It seems to me to know life's origin requires an explanation of the development of molecules with intense information content.
Now you want "intense" to mean something it does not. Your fuzzy thinking here is not helping.
But by what means does the energy flow keeping a system far from equilibirum generate information content?
Have you really never studied chemisty?
How does a mechanism that stores, transfers, and directs information arise spontaneously -- from balrog666's famous primaeval muck as it were?
By bootstrapping from simpler molecules. Why do you pretend you haven't read a hundred threads like this in the past? Or have you forgotten all the previous answers you've ever gotten to similar "questions"?
The sun can beat down on a mud puddle all day long, and still we would not see a living organism spring up as a result.
Molecule(s), not organism. you step too far. Oh, and by the way, those "puddles" probably comprised at least 10^18 cubic meters of chemical goo in a variety of conditions and concentrations. Oh, and "all day long" means at least 10^12 actual hours of sunlight - gee, can you calculate how much energy that is? Is it enough? How would you decide?
balrog666: Not by biologists.
According to H.H.Pattee, biologists are not concerned with the question. Physicists on the other hand are quite concerned by the question and have indeed broadly concluded that the difference between that which is alive and that which is not is information (Pattee, Rocha, Yockey, et al). Information is defined by Shannon as a successful communication. For instance, when a cell no longer communicates, it is dead.
Many biologists consider physical laws, artificial life, robotics, and even theoretical biology as largely irrelevant for their research. In the 1970s, a prominent molecular geneticist asked me, "Why do we need theory when we have all the facts?" At the time I dismissed the question as silly, as most physicists would. However, it is not as silly as the converse question, Why do we need facts when we have all the theories? These are actually interesting philosophical questions that show why trying to relate biology to physics is seldom of interest to biologists, even though it is of great interest to physicists. Questioning the importance of theory sounds eccentric to physicists for whom general theories is what physics is all about. Consequently, physicists, like the skeptics I mentioned above, are concerned when they learn facts of life that their theories do not appear capable of addressing. On the other hand, biologists, when they have the facts, need not worry about physical theories that neither address nor alter their facts. Ernst Mayr (1997) believes this difference is severe enough to separate physical and biological models: "Yes, biology is, like physics and chemistry, a science. But biology is not a science like physics and chemistry; it is rather an autonomous science on a par with the equally autonomous physical sciences."