Sunday, April 23, 2017

How the Moon may have been crucial for life on Earth

Summary: a container of objects can be shaken to result in tighter packing which means lower entropy. The moon has been doing the same to the Earth's water, mantle, and air in a way that is very different (if not opposite) to the Sun's heating. When life began, it provided more than 10% of the energy we are currently receiving from the Sun, maybe up to 50%. A close competitor to the title of "earliest life form known" is stromatolites, still living today in tide waters. Issac Asimov, at least, suggested life could not have made it out of the water without the moon. Viewed another way, the Earth-moon system may be in a low-entropy arrangement, like a gas chamber with two gases separated by a partition with a hole in it and the gases combining to form "copies" of durable bonds as one gas leaks into the other.

An arguing point against my thesis is that an alien machine might be capable of acquiring energy from the Sun and using it to shift through matter on Earth to create copies of itself. So my argument might be limited to "helping life to begin, extend its presence, or dominate more rapidly".

Life and our economic system have lower entropy per mass (aka specific or molar entropy) compared to the raw materials, but system-wide the entropy of Earth may not be lower. For example, when we remove oxygen from metal ores, carbon dioxide, and silicon dioxide the resulting mass of the metal, carbon, and silicon atoms that we use has a LOT lower entropy per mass. It appears to be offset by the entropy increase of the oxygen that is released to the atmosphere. Life and economics may or may not result in a lower net entropy on the face of the Earth, but it definitely results in a lower entropy for each atom we use in our systems. It makes sense our CPUs, hard materials, wiring, and solar panels should have a lower specific entropy: by being in more of a "known state" they can be commanded and controlled better. CPUs & Solar Cells (silicon based) and metal wiring need extremely low specific entropy due to needing to control the placement and/or movement of electrons. Brains are arguably 10 million times less efficient, primarily due to having to move ions that weigh 50,000 times more than electrons, with a lot less precision. As interesting as brains are, they are not as great a reduction in entropy compared to the raw materials. I have not calculated that cement is lower specific entropy compared to the raw materials, but I believe it is.

In regards to the Moon, Earth, entropy, and life: if you randomly drop balls or anything else with a definite shape into a container, they will not be packed as dense as possible, but if you shake the container (while it is in a gravitational field), they will pack more densely. Anything that is more densely packed will have a correspondingly lower entropy. Being in a smaller space means there’s fewer possible states. A harder material also has fewer possible states its atoms might be in for a given temperature because they can't vibrate as far away out of their medium position. The log of the number of states is proportional to entropy so fewer states is lower entropy.

Solid objects in the container are like the mass on Earth, unable to escape the container created by the mantle and gravity. The periodic force from an external source (the shaking) is like the Moon affecting the tides and mantle. Both systems are thermodynamically closed but not isolated: no mass comes in or out, external energy comes in, and heat and entropy go out. In both the container and Earth, the cyclical external force causes friction which will raise the temperature, and assuming both are surrounded by space, the temperature will rise until the black body radiation increase equals the energy from the external cyclical force, emitting heat energy and entropy as photons (S=4/3 U/T). Some potential energy source is driving the cyclical external force.  Potential energy from the source that is not converted to heat (and thereby emits radiation and entropy to the universe) can be used by the matter on Earth to create stronger, tighter-packing bonds that thereby lower the entropy per mass of Earth. Since no mass leaves the Earth, this means the entropy of Earth as a total may decrease.

So a periodic force on a system of particles in a closed but not isolated thermodynamic system in a gravitational or other field of force can result in lower entropy in the system. In other words, the moon may be an important original source of the congealing (hardening) of the matter on Earth, which we call life and economics. The incredibly unlikely and uncommon accident of another planetoid striking the Earth late in the formation of both seems to be the original injection of low entropy (The moon circling the Earth prevents an evening-out of the masses?) that resulted in the Earth-moon system being so darn interesting that it has given rise to life.

There is a huge difference in the type of energy received from the Sun verses the moon. They are actually opposites. The Sun causes heat differentials that can cause bulk matter to move. The moon moves bulk matter that can causes heat differentials. Getting back to my jar-shaking analogy, if the bottom solids get hotter then they will rise from being less dense and currents can occur which might help packing. But the moon is raising more-dense materials to the top then letting them fall. For example, it raises cold water "into" the air. The Sun must first turn the water to steam to do the same. It may be that the combination is important: the moon could be provided a macroscopic form of enabling lower entropy while the Sun, working on a microscopic level is working out details. The juxtaposition ("chaos") of the two, combined with the "return to status quo" being enforced by gravity, could be what makes life interesting.

I should add the influence of the moon may enable more of the medium-weight elements and molecules to be at the surface which enabled more interesting combinations. It may have enabled tighter packing at the surface but at the same time that's suggesting an anti-packing. Or maybe the initial impact was also like shaking a container that resulted in more of the heavier elements getting in the core which might have enabled or blocked life.

I am describing my jar as being full of solids seeking a closer arrangement, but I hope is sufficient enough to not be fundamentally different than if the solids had different levels of stickiness in different places, which is what occurs with molecules.

How can a macroscopic effect of the Moon affect or generate biochemistry? But maybe this is the wrong question when looking at evolution and life. People think of genes as spreading, but this an erroneous starting point that leads to looking at chemical reactions for an explanation of life. Genes are just enzymes. Potential energy gradients (forces) are the original source of all movement and "selfishness".  Genes are not potential energy and therefore are not a source of movement.  They are a result, not a cause. Genes do not "cause" their own replication. Potential energy gradients have pulled them into existence.

I'm proposing some of the rotational energy the Earth is losing due to the moon's presence has somehow helped Earth's biosphere (and "economics-sphere") learn how to extract energy from the Sun (and now other forms of nuclear energy) in order to store the energy in the form of metals, silicon, carbon-carbon bonds, and many biological systems and biochemistry. Life is removing some atoms to a further distance (mainly CO2 and O2) and combining the remaining atoms in a way that allows more strength, stability, longevity, and controllability.

I don't want to immediately include "replication" in this list of important characteristics of life without a full explanation because it immediately generates the idea that genes, brains, and corporations are actively doing something on their own. But replication, along with the other important characteristics of life, corresponds with lower entropy. "Copies" are almost a definition lower entropy. I want to keep "replication" at a distance in my considerations because it is so difficult to remember that genes do not desire to replicate. By extension, the idea that animals "want" to replicate should be only a handy, approximate myth that is not at all true in a deep sense. I think it is related to the way people used to think mind and body were distinctly different things. It requires believing that thought (or the programming in genes and corporations) affect other things on their own without acknowledging that the energy that created and drives them ultimately comes from somewhere else. ( To see that thought is ultimately based on energy, see Landauer's limit E=kT ln(2) which is the absolute minimal amount of energy required to stored or change ("compute") a bit of information. )

"Replication" might be a consequence of the lower of entropy, not merely something that happens to correspond to it. Since lower entropy corresponds to everything that underlies life, maybe it is the key. Maybe the Earth-moon system is the largest example of a lower-than-expected entropy system that we have, acting like a gas chamber with two gases that combine on contact, separated by a partition that has a hole in it. The combination releases heat and results in stronger bonds and we would see a "replication" of the "dance" and end products as time goes on. The Sun merely provides energy.

Pseudo-copies are kind of a requirement when there is a lowering entropy. As when we go to tighter packing arrangements in the container analogy, more arrangements are going to be more frequent. As the tightest bonds get stuck, the result is a smaller variety of bonds you might encounter, or rather you will encounter the tightest bonds more frequently than chance alone. So copies being more frequent might be a logical consequence, not a fictitious end goal of "selfish" genes. But the copies in life are enzymatic. That is, they "assist" the moon and Sun, through no force of their own, to "make" , copies, through no force of their own. The "through no force of their own" is hard to remember. But in what way is a spreading, reproducing chain of restaurants and its business and architectural blueprints enzymatic? It seems to be the exact same kind of process and yet it seems a lot less "enzymatic". By reducing the mysterious feel of enzymes, I hope to accentuate the potential importance of the moon.

Notice that all of the things to matter on Earth that life and economics find so useful also happens to be lower entropy.

Here are some things that are not from the moon that are like the effect I'm proposing:
  • Photons from the Sun cause temperature differences that can cause motion.
  • Lightening strikes have been theorized to have been important in the origins of life. They are the result of a potential energy gradient between a build-up of opposite charges. The original source of the buildup of the energy is the Sun and/or the Earth's rotation.  The moon may not have significantly increased the lightening strikes despite its effect on the atmosphere and rotation. The Earth's rotation, like Mars, may have been similar without the original Earth-moon collision.

  • The mantle may have done a lot of churning without the Moon and still resulted in our lower-entropy concentrations of ores and it may have had similar mountains (potential energy gradients) without the Moon.

The moon may increase or affect all of the above.  It also greatly stabilized the Earth's tilt which resulted in much more reliable seasons over much longer time periods. Others have seriously considered the moon's stabilizing of Earth's axis tilt is a rare characteristic feature of planets and was crucial to life developing here.  This may have helped the Sun's effects by more "cyclical" instead of chaotic. Without proof, I'll suggest cyclical forces may create more order than chaotic ones.

Last but not least is the effect the moon has had on tides. Isaac Asimov has written about how crucial the cyclical tides were for life to leave the oceans.  More importantly, potentially (but probably not) the oldest form of life on Earth known is stromatolites forming in tidal regions 3.7 billion years ago, about 0.7 billion years after the Moon was created. Another competitor is micro-organisms living off the potential energy difference from the sudden temperature change between hot vents in the ocean. Although it does not seem the moon was required to create them or keep them stable, it's possible that it was.

It seems the Sun is much more important for life to be sustained and grow. But maybe the presence of the moon initially caused a redistribution of atoms in the oceans and mantle to lower-entropy arrangements that made more interesting combinations possible.  On a grander scale, certain veins and ores are crucial to modern society. How important was the moon in the geology that has caused them to attain these lower-entropy concentrations? 

As I'll describe below, the energy from the moon when life began may have been 20x or more greater than it is today, reaching maybe more than 10% of the energy currently being received by the Sun.

Now I'll detail the amount of energy being given to the environment by the Earth-moon system and compare it to the Sun.  These are the current numbers. When life began, the Earth was spinning faster and the Moon was closer, so the effect was much greater when life began.  Wiki indicates the moon was about 10% closer 1 billion years ago, in keeping with the current rate of increase in the distance it is getting away, but that it may have been 15x closer soon after the impact. Certainly it was 3x closer when life began which means its gravitational effects were 9x greater, and since the Earth was spinning nearly twice as fast, the friction it generated in the water and mantle may have been 20x greater.

The moon is rising in orbit to a slightly higher potential energy each year, 3.78 cm/year due to receiving energy from the Earth's rotational energy. The moon is orbiting slower than the Earth turns, which is dragging on oceans and mantle to create the tides and more geologic events. The Earth slows 0.73 seconds per year which is 1E22 Joule/year loss in rotational energy. The moon's increase in gravitational potential energy is 7.6E18 Joule/year. The large difference between the two is the available "external" cyclical force source (energy) that I am claiming has helped cause mater on Earth to congeal to a more dense, lower-entropy state. The energy being injected into the oceans and mantle is 1,000x higher than the energy being used to raise the Moon to a higher orbit each year. The source of the energy is a loss in the Earth's rotational energy which may have been increased or decreased by the collision that created the moon.

( Previously I have argued this loss of the Earth's rotational energy is an internal energy loss which is known to spontaneously cause snowflakes (lower entropy) as a result of Gibbs free energy math.  A reaction is spontaneous and can result in lower entropy if the internal energy drop in the reactants is greater than the drop in temperature. Negative dG means spontaneous and dG=dU-TdS. But my argument on that fails when considering the Earth because it needs other "molecules" with rotational energy besides itself to form the "snowflake".  )

The 1E22 Joule/year from the Earth's rotational energy is huge. Most of it comes out as heat from friction in the tides and mantle. That creates temperature differences which might be useful as a "heat engine" to life, but it causes other potential energy differences such as waves, tides, and mountains. Going from there to genes is a long step, but the oldest life forms seemed to need these differences. to repeat, most of the energy is wasted heat which raises the Earth's temperature a very small amount above what the Sun is doing, and the energy gets lost to space as black body radiation. But some of it is getting transformed from Earth's rotational energy to potential energy in the placement of mass on the Earth such as mountains. I'm proposing some of it, which was especially important in the beginning of life on Earth, was getting stored as stronger chemical bonds, which lowers entropy per mole for the atoms involved.

Other than great temperature differences like the ocean vents, heating is not what I'm looking for.  There seems to be a certain quality of the moon's "shaking" that is a lot better than simple heating.  The Sun does a LOT of heating.

The Sun is adding 1.5E24 Joules/year with the current albedo of 0.3. This is only 150 times more energy than the current loss of the Earth's rotational energy. As I mentioned before this means when life began the moon may have accounted for 10% of what the Sun is currently doing. The Sun's energy causes a corresponding excess amount of black body radiation and entropy emission and "heat engines". So if my thesis is correct (that the moon was as crucial as the Sun in generating life and that it's based on an entropy or other thermodynamic effect), the type of energy being injected by the cyclical force of the moon is extremely important and that the character of the moon is somehow better than the Sun for life to arise in the beginning. The Sun's heat is a cycle thanks to day-night changes and it even causes macro cycles of mass movement in the air and water.  So it's not immediately obvious to me that my thesis is correct.  I need to show how the moon's cyclical force has an effect that is different from the Sun.  Now that life has arisen, the Sun's energy is obviously being used more than the effect of the moon.  

My shaking container analogy may be exactly what's occurring: the Sun does not shake the matter on Earth like the moon.  It's just a lot more heating. But the moon kept the Earth's mantle in a "shaking" state in it's first 1 billion if not 4 billion years, far longer than it otherwise would have been.  This should have brought a wider variety of atoms and compounds to the top and distributed in more interesting ways. An interesting crystal can't form as the environment cools if the atoms are not in the right place to begin with. And so it may have been with life.  Maybe life is just how atoms on Earth are cooling off after being placed in low-entropy arrangements thanks to the moon.

The first places we look for life in the solar system are similar bodies (Io and Titan?) where similar cyclical gravitational forces are at work, churning tides of gases, liquids, and/or mantles, creating a lot of interesting "chaos" that may lead to life.

It's very interesting that the 3rd grandest object known to cave men has always been idolized as a symbol of romance. It seems likely that it is indeed the crucial extra ingredient that made romance possible. No doubt the Earth is important. No doubt the Sun currently drives it. But was it the exotic after-effect, the moon, of the striking of two planetoids that made us interesting and interested?

"Replication" seems to be crucial to making life interesting. I would be good if I could find how the moon (or moon in concert with sun) is important to that aspect. But as I implied above "replication" or "spreading" might be a red herring. It may be that it is merely a consequence of the lowering of entropy. Pseudo-copies are kind of a requirement in lowering entropy. As when we go to tighter packing arrangements in the container analogy, more arrangements are going to be more frequent. As the tightest bonds get stuck as a result of the moon's cyclical force, the result is a smaller variety of bonds you might encounter, or rather you will encounter the tightest bonds more frequently than chance alone. So copies being more frequent is a logical consequence, not a fictitious end goal of "selfish" genes. But the copies in life are enzymatic. That is, they "assist" the moon and Sun, through no force of their own, to "make", through no force of their own, copies. But in what way is a spreading, reproducing chain of restaurants and its business and architectural blueprints enzymatic? It seems to be the exact same kind of process and yet it seems a lot less "enzymatic". By reducing the mysterious feel of enzymes, I hope to increase the potential importance of the moon.

The rest of this post is a meandering of "thinking out loud", if the above was not already so.

The stronger bonds that potentially lower the net entropy on Earth are also an increase in the mass via E=mc^2. That extra energy or mass originally comes from the Sun or the Earth's rotation (or radioactive decay inside the Earth). If it comes from the Earth's rotation, then it's not a net increase in Earth's energy or mass. But the photons released by the Sun were trying to escape the solar system and allow the universe to expand, but as they are caught by photosynthesis or other processes mass that was in the Sun is transferred to the Earth. I suppose the gravitons to and from the moon are a similar attempt of entropic forms of energy trying to escape, so I don't really have point except to note that there's another difference between the energy from the Sun and moon that might have some significance.

The resulting higher-energy bonds that life seeks deprives the universe of (I believe) and entropy of S=4/3 U/T (or the nearly equivalent dS=dQ/T) where U (or dQ) is the amount of energy from the Sun or moon's external forces that were 100% converted to stronger bonds on Earth instead of being emitted as black-body radiation. Entropy of the universe is actually known to be constant on a co-moving volume basis. See the foot note for a full explanation on how entropy in gravitational systems are required (by cosmological observation and the standard model) to exhibit a reduction in entropy as the universe expands. I'm claiming that if we could 100% convert the Sun's energy to stronger and stronger bonds of our local mass at "0" degrees kelvins so that no U leaves our system, then we would be preventing some of the Universe from expanding. Wasting energy seems to be "anti-life" (more entropy).

Foot note:
The 2nd law is incorrectly stated as “entropy always increases” and for decades popular books have incorrectly proclaimed there will be a "heat death" of the Universe.  The idea that "entropy always increases" is an engineering idealization that is useful for designing engines.  But due to black body radiation, there is no such thing as an isolated system. See the famous physicist Richard Feynman’s chapter on thermodynamics where he explains "entropy always increases" is not correct and gives the standard, correct equation. The Universe (in observation and the standard model) has constant entropy on a comoving volume basis which means all gravitational systems inside a "fixed volume" are perpetually emitting entropy to the universe “in order for the universe to expand”. See the Steven Weinberg’s famous book “The first 3 minutes” about how conservation of entropy overrides even conservation of energy in the standard model of the universe.  As internal energy is converted to heat, 4/3 U/T entropy is emitted to the Universe via black body radiation.

No comments:

Post a Comment