Speculations inspired by James Lovelock
OK, so for decades I suffered from the ignorant misconception that James Lovelock was a muddleheaded woo-woo, and that the Gaia Hypothesis was anthromorphic teleology at its worst.
I picked up "Vanishing Face of Gaia" and discovered a kindred spirit ( perhaps too kindred for Dr. Lovelock's own good :-/ ). Gaia is a metaphor for a homeostatic biosphere, not anthropomorphic or teleological at all. The deficiency in the idea is that the name drives hard-edged scientists apoplectic. The framework is illuminating and inspiring, but hard to pin down to specifics and numerically testable corollaries - much like Darwin before Mendelian genetics. So far, only a fraction of the myriad Gaian mechanisms and even fewer of their evolutionary histories have been identified. Again, like Darwin's theory, this is a measure of the vastness of the task ahead, and is not a flaw in the good work already done. From a system perspective, it is obvious that life affects the planet geologically and even astronomically, and that some of those effects make the planet more livable for individual organisms. It is philosophically obvious that some the development pathways are difficult to fit into a strict selectionist Darwinian frame.
All that said, these are problems with the existing ways of doing silo'ed science, and with the newness of the idea, not with its validity, vitality, or centrality to the way we will be doing science decades from now.
Dr. Lovelock is an independent scientist, while his income and much of his daily activity has been invention. His work output is engineering and system architecture. I relate to that strongly. His deep involvement with physical things and industrial organizations predisposes him to look at whole, real systems, not tinker-toy model systems which are small enough to encompass with simple analysis. So, Dr. Lovelock's "errors" are not acceptable to those immersed in the far larger error of studying only tinker-toy models while assuming they tell us all we can know about the world.
Unrealistically simplified models may be "accurate" within their constraints, but the constraints themselves are glaring inaccuracies that the universe (and most practical people) simply ignore. "Consider a spherical chicken", as the old joke goes. We are entering an era where we will construct less-constrained models that can be scored and ranked for rigor, completeness and accuracy, but cannot be understood as a whole, or deduced from a small set of postulates. Like the four-color map problem, we will be able to prove the process that makes these computerized or distributed models, but our brains are too small to encompass the entire model the automated process emits. So Lovelock's idea comes at a time when reductionist science still rules, but will be right at home in a future more adept at modeling complex systems.
Complex system modeling methods are already developed for the design of integrated circuits, cryptological algorithms, communication in noisy channels, and other large, complicated and sometimes-indeterminate systems. These methods are not free of flaws. However, leaving out real effects and real complications because they are too hard to analyze is a much bigger flaw in the world that practical artificers work in. Complete understanding is not an option, and intellectual compartmentalization cripples as often as it reduces problems to managability.
Dr. Lovelock's industrial interactions saved him from the cargo-cult mentality of many Greens, who don't understand that the industrial and commercial systems they rail against provide the goods and services that these individuals need to survive, and most importantly, do so with an efficiency and low environmental cost that so-called alternatives do not approach. Lovelock calls for more nuclear power to replace fossil fuels, which I heartily agree with.
Dr. Lovelock also calls for more terrestrial solar power, which I mostly disagree with for habitat destruction reasons. While the replacement of desert ecosystems by solar farms may seem to be no great loss to a person living in moist and arable Britain, deserts host abundant life, dependent on the sun, much of it below the surface where it is not obvious to casual visitors. We may find that those systems are critical to the survival of the biosphere, and it may be suicidal to destroy them before we understand all that they do. If the world is desertified by global warming, our own survival may depend on genetic engineering of new cultivars from the lifeforms in these regions.
I do agree with solar power for non-habitat areas such as rooftops, or for powering remote systems that would otherwise need power lines or generators (and the associated mineral extraction, manufacturing, and maintenance, also ecologically damaging). And I strongly agree with using the other 380 trillion terawatts leaving the sun and blowing into empty space, subject to limits imposed by infrared re-radiation and nighttime light pollution. Life - in the sense of local knots of counterentropy - can be expanded by factors of trillions in space, and those who argue that "Gaia hasn't reproduced" ignore both the technological and meteoric means by which life has and will eventually spread itself.
So, three rousing cheers (and one faint raspberry) for Dr. Lovelock.
Speculations about Life and Astronomy
The Gaia hypothesis was inspired by Dr. Lovelock's observations of Mars. Mars is effectively lifeless because it is close to chemical equilibrium and maximum entropy. Living systems follow their own paths to maximum entropy but leave artifacts on the way to it, such as atmospheres with methane-oxygen mixes.
The entropy arguments are interesting. With insufficient activation energies, most non-ionized systems get "stuck" at plateaus of locally-but-not-globally maximum entropy. In spite of the seemingly counter-entropic organization of living systems, they actually process low-entropy energy to a higher-entropy state than lifeless systems can manage. In a strictly information/entropy sense, the lower entropy of living structures is overwhelmed by the entropy increase of the energy needed to make those structures.
That said, living systems make it to higher entropy plateaus than non-living systems, and those plateaus are both radically different and easily observed. Since life has been processing 20,000 terawatts of energy for billions of years, and humans have been processing about 10 terawatts of energy for a few decades, it is not surprising that the effects of life may be easier to detect at astronomical distances than the effects of intelligence.
A surprising astronomical effect of life results from tidal forces. Lovelock and Margulis argue that the homeostatic processes of life preserved both a liquid ocean and plate tectonics (by depositing the calcium carbonates that lubricate plate boundaries). Unlike Mars or Venus, the Earth has large and separated basins filled with kilometers of water. As this water sloshes back and forth under the tidal action of the sun and moon, it in turn exchanges angular momentum between the Earth's rotation and the orbit of the Moon and of the Earth itself.
The current estimate for the slowing of Earth's rotation is 2.2 seconds per 100,000 years. Let's ignore crustal tides, light pressure, differential absorption of cosmic dust, and assume that 20 seconds per megayear is caused by ocean tides, about 3 hours per day slowdown since 540 MYA, when the day was about 21 hours.
Most of that angular momentum has been added to the orbit of the moon, moving it radially outwards by 40 kilometers per megayear, or 22000 kilometers since 540 MYA, and increasing the length of the month by 48 hours. The angular position of the moon in its orbit has been displaced by a third of a billion orbits compared to the non-tidal oversimplified case. The effect on the Earth's rotation is more extreme, more than 10%, and the angular displacement accumulated over 540MY is 30 billion turns (out of 200 billion).
So, if bacteria preserved the ocean, then bacteria moved the moon, outwards by 20 thousand kilometers, retrograde in its orbit by 100 light years. The tidal coupling effects on the earth, and its position in orbit, are left as an exercise for the reader.
The Chixulub impactor, and tides, and life
Consider the Chixulub impactor, causing the K-T extinction 65 million years ago. Some say that if this massive impact had instead occured on dry land, the effect would have been much smaller. If it had landed in deep ocean, it might have steam-cleaned land of life. In fact, the impactor hit a sulfur deposit on the shallow coastline of the Yucatan, creating a vast cloud of sulfuric acid that killed large animals like the dinosaurs [ citation needed ]. A few degrees west or east, and the results would have been far different - and we would not be here.
3 degrees of turn, out of 30 billion fewer turns of tidally caused displacement rotation, is about one part per four trillion of the total effect of the tides over 540 MY. If the tides were 0.25 ppt smaller or larger, the K-T impactor would have landed elsewhere, with much different results. Assuming an average ocean depth of 4 kilometers, and (wildly) assuming that the tidal effects are proportional to depth, then a change in ocean depth of +/-1 nanometer would have made the impactor miss the sulfur deposit.
And if the effect of life has been to preserve the ocean, and the ocean was going away at a rate that would have dried it up in a billion years without life, then it is plausible (sort-of) to assume that the boiloff rate was on the order of 4 micrometers per year, or 10 nanometers per day. Thus, if life on Earth had gotten started three hours earlier or later ...
This is balderdash, of course. These systems are nonlinear and chaotic, and initial conditions are washed out by intervening noise and nonlinear amplification of small initial effects. Gaia would need to be goal-oriented, and very aware and intelligent, to manage things so the Earth was positioned just so in its rotation and orbit to force the historical outcome. It would make a great fantasy story, though.
It's fun to read your musings on the topic Keith. Is the metaphor itself unpalatable for hard-science types? Or would a different name achieve more acceptance? --Brandon