Friday, May 22, 2009

Paradigm Shifts - II

One of the more fascinating aspects of this subject—world views, paradigms—is that we apparently know much more about the cosmos than we know about our own backyard. Studies of the big bang knowledgably discuss events said to have transpired one or two millionth of a second after the big bang began, but our very best theories of the solar system’s origins are very speculative at best. I will document this presently but want to draw the conclusion first. The closer we are to actual realities—and therefore our data are ample and our measurements good—the more obvious become the paradoxical features of reality and the more clearly we see that our explanations are groping, flailing, and often rather arbitrary. For this reason astronomers are much more realistic and tentative in discussing the solar system than they are theorizing about the universe. And apparently far more people spend far more time on the cosmos than on the messy solar system. But let’s look at that system.

Today’s dominant theory of the solar system’s formation presumes that it is the condensation of a cloud of dust and gases, a nebula. This cloud eventually collapsed into our sun when matter at its center aggregated initially by random motions. Under the force of the increasing gravity, the rest of the cloud flattened into a disk rotating in a counter-clockwise direction as perceived relative to the sun from the Earth. Within that disk clumps formed. They are called planetismals—for planetary seeds. Planetismals aggregated yet more material and became planets. By secondary processes, these bodies in turn, also rotating, caused moons to form around them. The planets in the aggregate account for about 1 percent of all the matter in the original cloud, the sun for 99 percent. This suggests that the sun itself should have the greatest angular momentum in the system in that it has the greatest mass. The inner planets are small, dense, and heavy; the outer are large and gaseous—and this distributional effect is due to sorting by density under the gravitational influence of the sun. All this makes sense, of course: one thinks of a blender, with the rod of the blender creating a little hole in the middle representing the pull of gravity.

Indeed the picture, and the theory, would be indisputable if only the solar system—and stellar clouds, for that matter—obliged us by behaving properly. For starters there is the fundamental problem, explained away by various stratagems, that vast clouds of dust just don’t clump up but, instead, have the tendency to spread. But never mind that. Assuming that the process starts somehow, proper behavior would be indicated if (1) the sun had nearly all of the angular momentum of the system, (2) if all of the planets rotated around their axes in the same direction as the sun, i.e., counter-clockwise, (3) if their axes were oriented in the same direction, i.e. parallel with the sun’s, and (4) if their moons also obligingly circled them in the same direction and with the same spin-direction as the planets themselves exhibit when circling the sun. The composition of planets and moons should also be in line with their location. Thus the moon should be as dense as the earth and the moons of Jupiter as gaseous as that planet.

The real facts are otherwise. The sun, with 99 percent of mass, has only 3 percent of the solar system’s angular momentum—Jupiter has 60 percent. Venus, Uranus, and Pluto rotate clockwise. The axis of the Earth is tilted at an angle to the sun’s. The axes of Uranus and Pluto point at the sun. Some of Jupiter’s moons circle it counter-clockwise, others clockwise. And the moon is of a much lighter density than the Earth’s so that its origin cannot be—and is not—attributed to condensation. We are thus faced with a sequence of questions: How did the sun lose its momentum, how did the rebellious planets acquire their contrary rotations, how did the axes of some planets get their tilt? Where does the moon originate and when did we get her? In addition to such questions we have yet other strange anomalies: the asteroid belt is one, the rings of Saturn another, and the comets (they come in two categories) yet a third. Pluto presents us with the interesting fact it has been demoted from planetary status in our lifetime. It has a rather eccentric orbit.

Notice the elegance of the original theory and the messy details of actual behavior. In all such cases science has a tendency to introduce ad hoc explanations which, while plausible in human experience (“Shit happens,” as we say), are difficult to reconcile and to embed neatly in a coherent and unified theory.

The nebular theory, which goes way back to Descartes (who imagined a gigantic whirlpool in a cosmic fluid), later developed a “catastrophic” competitor. Under this scenario, the sun encountered another sun wandering the cosmos. The intruder, interacting with the sun, ripped a huge tide of matter from the sun which, condensing out, formed the planets. This theory had the benefit of at least potentially explaining the sun’s low angular momentum—by hypothesizing that the visiting body gave up some of its angular energy to the ripped-out tide. The action itself—being, in a sense, wide-open to the imagination—could at least vaguely explain the strange rotations of Venus, Uranus, and Pluto. But the catastrophic theory lost momentum. It had its origins with Buffon in 1745, thus in the period leading up to the French Revolution. All things “revolutionary” were strongly resisted in the next century—hence the success of Darwin’s gradualistic theory of evolution based on Lyle’s gradualistic geology, which Lyle in part formed to counter Georg Cuvier’s catastrophic vision; Cuvier, of course, had studied actual geology and had reached his startling conclusions by looking. The realistic critique of the “tidal” theory is that such a violent encounter would more likely result in the dispersal rather than in the condensation of matter.

Despite the rejection of catastrophic origins, that theory still plays a major role in today’s consensus opinion in yet more ad hoc formulations. Thus the contrary rotations of three planets (or two if you don’t include Pluto) are explained by collisions and interactions between planetismals; but how these bodies got into erratic motion in the first place is not really developed. Similarly, the asteroid belt is explained either as the shatter of a planet or the inhibiting influence of Jupiter preventing aggregation. G.P. Kuiper (known for predicting the Kuiper Belt on the fringes of the solar system) speculated in 1951 that the sun’s planetary systems are the consequence of a failure. “It almost looks as though the solar system is a degenerate double star,” he wrote, “in which the second mass did not condense into a single star but was spread out—and formed the planets and comets.” Jupiter’s distance from the sun and the mass of the planets as a whole are about right (based on observation of binary systems) to support this hypothesis. But this notion also fails to explain the existing anomalies. Theories for the moon’s origin are based either on catastrophic interactions, e.g., the moon having been ripped from the relatively light outer mantle of the Earth by a passing body (a tidal theory in miniature), or on erratic wandering bodies, with the moon being captured by the Earth. Comets, the strange orbits of which do not fit the nebular theory—and there are short as well as long-period comets—are often the deus ex machina invoked to explain catastrophic events. To be sure, they don’t properly fit any elegant picture of the solar system’s orderly formation.

The closer we are to our subject the more variables appear to be present and therefore mathematical modeling of systems is more difficult. In cosmology, for instance, a few simple subatomic particles plus gravity, pressure, mass, and heat are the manageably few variables. Even so, the big bang theory failed to predict the formation of suns and galaxies until Alan Guth offered a rather arbitrary scenario in 1980. In its earliest stages, Guth said, the universe temporarily accelerated its expansion, a process known as “inflation.” In this process evidently gravity had to work in reverse (!!) There is no way to verify inflation, but it is accepted. Without this “kick” or “leap” of faith, the theory would have died an early death. What kept it alive—and the reason why Guth found support—was because the overall expansion of the universe, discerned from the red shift, had to be explained somehow. But the point here is that even a simple model with just a few variables, had and continues to have problems. How much more so the solar system—and never mind DNA.

The reason why mathematical models are so important is because they seem to bring coherence to what at first appear as irreducibly chaotic phenomena. Modeling imposes an order on chaos but usually at the cost of simplifying the inputs by leaving out much or averaging what seem to be minor influences. Models then produce predictions which can be tested by observation. The difficulties and limitations of modeling, however, are neatly illustrated by the cleverness of pre-Galilean modelers of the solar system. Their model accurately predicted the future position of planets although it was constructed on the assumption that the earth stood still and all else moved. It also became very complex as ever new solutions had to be devised to accommodate ever new observations that failed to fit properly. The Ptolemaic model was eventually replaced when better instruments emerged. Today’s big bang theory is accumulating ever more hypotheses and ever more work-arounds, like the Ptolemaic model did in the past. The big bang is under challenge from all sides. It requires Guth’s strange inflation; the cosmos displays large structures for the formation of which insufficient time has passed; one of these is the Great Wall, the first such discovered, others have been noted as well; a picture of it is here. In recent decades, furthermore, gravitational anomalies have been observed countered by positing undetectable dark matter and dark energy which constitute the overwhelming mass of the cosmos(!??). Indeed, doubters within science itself have identified twenty or more anomalies the theory fails to explain adequately—and plasma physics, which emerged in the mid-twentieth century in sophisticated form, offers alternative avenues of explanation. Cosmology is therefore gradually sliding into crisis.

Einstein’s theory of relativity is also eroding as discoveries in quantum physics have produced physical evidence for faster-than-light communications between subatomic particles—to name just one instance. Quantum physics is itself the earliest child of a physics largely developed in the changing—and indeed darkening—times of what seems a new era to me. It dissolves Einstein’s reality into energy, suggests that the predictabilities of physics are confined to macroscopic aggregates of energy, i.e., matter as we see it, and that beneath it is a boundless indeterminacy which may require an observer to become visible at all. The universe is thus a vast cloud of probability; observation causes probability waves to collapse; the observer becomes integral to the universe and, in a sense, creates reality.

Arguably if the observer really has a role in quantum physics, that observer should be explained as well. The positivistic explanations of intelligence seem inadequate to the purpose and may foreshadow changes in the area most resistant to change, the naturalistic theories of life.

Finally, in psychology, a hydra-headed cluster of genuinely scientific findings, both positive and negative, are weakening the positivist consensus that mind its an epiphenomenon. Interesting approaches are from the angle of the paranormal—including psychic powers in animals and hard research into reincarnation. Negative data show the persistent failure of naturalistic science in locating memory in the brain itself.

In sum, the paradigms they are a changing. Will the new theories, as they emerge and take hold, exhaustively describe the cosmos, life, and man? I doubt it.

The last word belongs to Heraclitus who claimed that there is a tendency in nature for all things to become their opposites. He labeled this enantiodromia, meaning “counter-running.” One might say that every such transformation produces a new vision of reality but never one that is complete. Around and round she goes, but where she stops nobody knows.

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