Addendum on Emergent Complexity

Tuesday

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This post is intended as a quick addendum to my post The Apotheosis of Emergent Complexity, in which I considered, in turn, the respective peaks of star formation, life, and civilization during the Stelliferous Era, as exemplifying significant forms of emergent complexity in the universe.

The apotheosis of emergent complexity recognized in that earlier post — when stars, life, and civilization are all represented — can be further narrowed in scope beyond the parameters I previously set. With the sole examples of ourselves as representing life and civilization, we can acknowledge a minimal form of the apotheosis of emergent complexity already extant, and as long as our civilization endures and continues in development it retains the possibility of seeing further emergent complexities arise. Among the further emergent complexities that could arise from terrestrial life and civilization is the possibility of this life and civilization expanding to other worlds. A simple expansion would represent the spatial and temporal extension of emergent complexity, but life and civilization almost certainly will be changed by their adaptation to other worlds, and this adaptive radiation on a cosmological scale may involve the emergence of further emergent complexity (in which case a fourth peak would need to be defined beyond stars, life, and civilization).

An expansion of terrestrial life and civilization into the universe that constitutes an adaptive radiation on a cosmological scale, is an event that I have called the Great Voluntaristic Divergence (in Transhumanism and Adaptive Radiation) — “great” because it takes place on a cosmological scale that dwarfs known adaptive radiations on Earth by many orders of magnitude, “voluntaristic” because both the direction and the nature of the radiation and the adaptation will be a function of conscious and intelligent choice, and “divergence” because different choices will lead to the realization of diverse forms of life and civilization not existing, and not possible, on Earth alone. We can think of the Great Voluntaristic Divergence as a “forcing” event for the principle of plenitude. I have noted previously that cosmology is the principle of plenitude teaching by example. When the principle of plenitude works at the scale of the cosmos and at the level of complexity of civilization, further emergent complexity may yet transform the universe.

If we take the peak of emergent complexity as beginning with the Great Voluntaristic Divergence, this peak of emergent complexity so conceived will end with the End Stelliferous Mass Extinction Event (which I first formulated in my Centauri Dreams post Who will read the Encyclopedia Galactica?). Once star formation ceases, the remaining stars will burn out one by one, and, as they wink out, the planetary surfaces on which they have been incubating life and civilizations will go dark. Any life or civilization that survives the coming darkness of the Degenerate Era, the Black Hole Era, and the Dark Era, will have to derive its energy flows from some source other than stellar energy flux concentrated on planetary surfaces, which I noted in my previous post, Civilizations of Planetary Endemism, typify the origins of civilizations during the Stelliferous Era.

If life and civilization endure for so long as to confront the end of the Stelliferous Era, there will be plenty of time to prepare for alternative methods of harnessing energy flows. Moreover, I strongly suspect that the developmental course of advanced civilizations — the only kind of civilizations that could so endure — will experience demographic changes that will bring populations into equilibrium with their energy environment, much as we have seen birth rates plummet in advanced industrialized civilizations where scientific medicine reduces infant mortality, lengthens life, and increases the costs of child-rearing. When the End Stelliferous Mass Extinction Event is visited upon our distant descendants and their successor institution to civilization, their horizons will already have been altered to accommodate the change.

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The Apotheosis of Emergent Complexity

Thursday

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David Christian and Stephen Jay Gould on Complexity

The development of the universe as we have been able to discern its course by means of science reveals a growth of emergent complexity against a background of virtually unchanging homogeneity. Some accounts of the universe emphasize the emergent complexity, while other accounts emphasize the virtually unchanging homogeneity. The school of historiography we now call Big History focuses on the emergent complexity. Indeed, Big Historians, most famously David Christian, employ a schematic hierarchy of emergent complexity for a periodization of the history of the universe entire.

David Christian, the best known figure in Big History, emphasizes emergent complexity over cosmological scales of time.

In contradistinction to the narrative of emergent complexity, Stephen Jay Gould frequently emphasized the virtually unchanging homogeneity of the world. Gould argued that complexity is marginal, perhaps not even statistically significant. Life is dominated by the simplest forms of life, from its earliest emergence to the present day. Complexity has arisen as an inevitable byproduct of the fact that the only possible development away from the most rudimentary simplicity is toward greater complexity, but complexity in life remains marginal compared to the overwhelming rule of simplicity.

When we have the ability to pursue biology beyond Earth, to de-provincialize biology, as Carl Sagan put it, this judgment of Gould is likely to be affirmed and reaffirmed repeatedly, as we will likely find simple life to be relatively common in the universe, but complexity will be rare, and the more life we discover, the less that complex life will represent of the overall picture of life in the universe. And what Gould said of life we can generalize to all forms of emergent complexity; in a universe dominated by hydrogen and helium, as it was when it began with the big bang, the existence of stars, galaxies, and planets scarcely registers, and 13.7 billion years later the universe is still dominated by hydrogen and helium.

Stephen Jay Gould characterized emergent complexity as the ‘long tail’ of a right-skewed distribution that distracts us from the vast bulk of simple life.

Here is how Gould characterized the place of biological complexity in Full House, his book devoted to an exposition of life shorn of any idea of a trend toward progress:

“I do not deny the phenomenon of increased complexity in life’s history — but I subject this conclusion to two restrictions that undermine its traditional hegemony as evolution’s defining feature. First, the phenomenon exists only in the pitifully limited and restricted sense of a few species extending the small right tail of a bell curve with an ever-constant mode at bacterial complexity — and not as a pervasive feature in the history of most lineages. Second, this restricted phenomenon arises as an incidental consequence — an ‘effect,’ in the terminology of Williams (1966) and Vrba (1980), rather than an intended result — of causes that include no mechanism for progress or increasing complexity in their main actions.”

Stephen Jay Gould, Full House: The Spread of Excellence from Plato to Darwin, 1996, p. 197

And Gould further explained the different motivations and central ideas of two of his most influential books:

“Wonderful Life asserts the unpredictability and contingency of any particular event in evolution and emphasizes that the origin of Homo sapiens must be viewed as such an unrepeatable particular, not an expected consequence. Full House presents the general argument for denying that progress defines the history of life or even exists as a general trend at all. Within such a view of life-as-a-whole, humans can occupy no preferred status as a pinnacle or culmination. Life has always been dominated by its bacterial mode.”

Stephen Jay Gould, Full House: The Spread of Excellence from Plato to Darwin, 1996, p. 4

Gould’s work is through-and-through permeated by the Copernican principle, taken seriously and applied systematically to biology, paleontology, and anthropology. Gould not only denies the centrality of human beings to any narrative of life, he also denies any mechanism that would culminate in some future progress of complexity that would be definitive of life. Gould conceived a biological Copernicanism more radical than anything imagined by Copernicus or his successors in cosmology.

Emergent Complexity during the Stelliferous Era

How are we to understand the cohort of emergent complexities of which we are a part and a representative, and therefore also possess a vested interest in magnifying the cosmic significance of this cohort? Our reflections on emergent complexity are reflexive (as we are, ourselves, an emergent complexity) and thus are non-constructive in the sense of being impredicative. Perhaps the question for us ought to be, how can we avoid misunderstanding emergent complexity? How are we to circumvent our cognitive biases, which, when projected on a cosmological scale, result in errors of a cosmological magnitude?

Emergent complexities represent the “middle ages” of the cosmos, which first comes out of great simplicity, and which will, in the fullness of time, return to great simplicity. In the meantime, the chaotic intermixing of the elements and parts of the universe can temporarily give rise to complexity. Emergent complexity does not appear in spite of entropy, but rather because of entropy. It is the entropic course of events that brings about the temporary admixture that is the world we know and love. And entropy will, in the same course of events, eventually bring about the dissolution of the temporary admixture that is emergent complexity. In this sense, and as against Gould, emergent complexity is a trend of cosmological history, but it is a trend that will be eventually reversed. Once reversed, once the universe enters well and truly upon its dissolution, emergent complexities will disappear one-by-one, and the trend will be toward simplicity.

We can’t simply take the thresholds of emergent complexity recognized in Big History and reverse them in order to obtain the future history of the universe.

One could, on this basis, complete the sequence of emergent complexity employed in Big History by projecting its mirror image into the future, allowing for further emergent complexities prior to the onset of entropy-driven dissolution, except that the undoing of the world will not follow the same sequence of steps in reverse. If the evolution of the universe were phrased in sufficiently general terms, then certainly we could contrast the formation of matter in the past with the dissolution of matter in the future, but matter will not be undone by the reversal of stellar nucleosynthesis.

The Structure of Emergent Complexity

Among the emergent complexities are phenomena like the formation of stars and galaxies, and nucleosynthesis making chemical elements and minerals possible. But as human beings the emergent complexities that interest us the most, perhaps for purely anthropocentric reasons, are life and civilization. We are alive, and we have built a civilization for ourselves, and in life and civilization we see our origins and our end; they are the mirror of human life and ambition. If we were to find life and civilization elsewhere in the universe, we would find a mirror of ourselves which, no matter how alien, we could see some semblance of a reflection of our origins and our end.

Recognizable life would be life as we know it, as recognizable civilization would be civilization as we know it, presumably following from life as we know it. Life, i.e., life as we know it, is predicated upon planetary systems warmed by stars. Thus it might be tempting to say that the life-bearing period of the cosmos is entirely contained within the stelliferous, but that wouldn’t be exactly right. Even after star formation ceases entirely, planetary systems could continue to support life for billions of years yet. And, similarly, even after life has faded from the universe, civilization might continue for billions of years yet. But each development of a new level of emergent complexity must await the prior development of the emergent complexity upon which it is initially contingent, even if, once established in the universe, the later emergent complexity can outlive the specific conditions of its emergence. This results in the structure of emergent complexities not as a nested series wholly contained within more comprehensive conditions of possibility, but as overlapping peaks in which the conditio sine qua non of the later emergent may already be in decline when the next level of complexity appears.

The Ages of Cosmic History

In several posts — Who will read the Encyclopedia Galactica? and A Brief History of the Stelliferous Era — I have adopted the periodization of cosmic history formulated by Adams and Greg Laughlin, which distinguishes between the Primordial Era, the Stelliferous Era, the Degenerate Era, the Black Hole Era, and the Dark Era. The scale of time involved in this periodization is so vast that the “eras” might be said to embody both emergent complexity and unchanging homogeneity, without favoring either one.

The Primordial Era is the period of time between the big bang and when the first stars light up; the Stelliferous Era is dominated by stars and galaxies; during the Degenerate Era it is the degenerate remains of stars that dominate; after even degenerate remains of stars have dissipated only massive black holes remain in the Black Hole Era; after even the black holes dissipate, it is the Dark Era, when the universe quietly converges upon heat death. All of these ages of the universe, except perhaps the last, exhibit emergent complexity, and embrace a range of astrophysical processes, but adopting such sweeping periodizations the homogeneity of each era is made clear.

Big History’s first threshold of emergent complexity corresponds to the Primordial Era, but the remainder of its periodizations of emergent complexity are all entirely contained within the Stelliferous Era. I am not aware of any big history periodization that projects the far future as embraced by Adams and Laughlin’s five ages periodization. Big history looks forward to the ninth threshold, which comprises some unnamed, unknown emergent complexity, but it usually does not look as far into the future as the heat death of the universe. (The idea of the “ninth threshold” is a non-constructive concept, I will note — the idea that there will be some threshold and some new emergent complexity, but even as we acknowledge this, we also acknowledge that we do not know what this threshold will be, nor do we known anything of the emergent complexity that will characterize it). Another periodization of comparable scale, Eric Chaisson’s decomposition of cosmic history into the Energy Era, the Matter Era, and the Life Era, cut across Adams and Laughlin’s five ages of the universe, with the distinction between the Energy Era and the Matter Era decomposing the early history of the universe a little differently than the distinction between the Primordial Era and the Stelliferous Era.

Peak Stelliferous

The “peak Stelliferous Era,” understood as the period of peak star formation during the Stelliferous Era, has already passed. The universe as defined by stars and galaxies is already in decline — terminal decline that will end in new stars ceasing the form, and then the stars that have formed up to that time eventually burning out, one by one, until none are left. First the bright blue stars will burn out, then the sun-like stars, and the dwarf stars will outlast them all, slowly burning their fuel for billions of years to come. That is still a long time in the future for us, but the end of the peak stelliferous is already a long time in the past for us.

In the paper The Complete Star Formation History of the Universe, by Alan Heavens, Benjamin Panter, Raul Jimenez, and James Dunlop, the authors note that the stellar birthrate peaked between five and eight billion years ago (with the authors of the paper arguing for the more recent peak). Both dates are near to being half the age of the universe, and our star and planetary system were only getting their start after the peak stelliferous had passed. Since the peak, star formation has fallen by an order of magnitude.

The paper cited above was from 2004. Since then, a detailed study star formation rates was widely reported in 2012, which located the peak of stellar birthrates about 11 billion years ago, or 2.7 billion years after the big bang, in which case the greater part of the Stelliferous Era that has elapsed to date has been after the peak of star formation. An even more recent paper, Cosmic Star Formation History, by Piero Madau and Mark Dickinson, argues for peak star formation about 3.5 billion years after the big bang. What all of these studies have in common is finding peak stellar birthrates billions years in the past, placing the present universe well after the peak stelliferous.

Peak Life

A recent paper that was widely noted and discussed, On The History and Future of Cosmic Planet Formation by Peter Behroozi and Molly Peeples, argued that, “…the Universe will form over 10 times more planets than currently exist.” (Also cf. Most Earth-Like Worlds Have Yet to Be Born, According to Theoretical Study) Thus even though we have passed the peak of the Stelliferous in terms of star formation, we may not yet have reached the peak of the formation of habitable planets, and population of habitable planets must peak before planets actually inhabited by life as we know it can peak, thereby achieving peak life in the universe.

The Behroozi ane Peeples paper states:

“…we note that only 8% of the currently available gas around galaxies (i.e., within dark matter haloes) had been converted into stars at the Earth’s formation time (Behroozi et al. 2013c). Even discounting any future gas accretion onto haloes, continued cooling of the existing gas would result in Earth having formed earlier than at least 92% of other similar planets. For giant planets, which are more frequent around more metal-rich stars, we note that galaxy metallicities rise with both increasing cosmic time and stellar mass (Maiolino et al. 2008), so that future galaxies’ star formation will always take place at higher metallicities than past galaxies’ star formation. As a result, Jupiter would also have formed earlier than at least ~90% of all past and future giant planets.”

We do not know the large scale structure of life in the cosmos, whether in terms of space or time, so that we are not at present in a position to measure or determine peak life, in the way that contemporary science can at least approach an estimate of peak stelliferous. However, we can at least formulate the scientific resources that would be necessary to such a determination. The ability to take spectroscopic readings of exoplanet atmospheres, in the way that we can now employ powerful telescopes to see stars throughout the universe, would probably be sufficient to make an estimate of life throughout the universe. This is a distant but still an entirely conceivable technology, so that an understanding of the large scale structure of life in space and time need not elude us perpetually.

Even if life exclusively originated on Earth, the technological agency of civilization may engineer a period of peak life that follows long after the possibility of continued life on Earth has passed. Life in possession of technological agency can spread itself throughout the worlds of our galaxy, and then through the galaxies of the universe. But peak life, in so far as we limit ourselves to life as we know it, must taper off and come to an end with the end of the Stelliferous Era. Life in some form may continue on, but peak life, in the sense of an abundance of populated worlds of high biodiversity, is a function of a large number of worlds warmed by countless stars throughout our universe. As these stars slowly use up their fuel and no new stars form, there will be fewer and fewer worlds warmed by these stars. As stars go cold, worlds will go cold, one by one, throughout the universe, and life, even if it survives in some other, altered form, will occupy fewer and fewer worlds until no “worlds” in this sense remain at all. This inevitable decline of life, however abundantly or sparingly distributed throughout the cosmos, eventually ending in the extinction of life as we know it, I have called the End Stelliferous Mass Extinction Event (ESMEE).

Peak Civilization

If we do not know when our universe will arrive at a period of peak life, even less do we know the period of peak civilization — whether it has already happened, whether it is right now, right here (if we are the only civilization the universe, and all that will ever be, then civilization Earth right now represents peak civilization), or whether peak civilization is still to come. We can, however, set parameters on peak civilization as we can set parameters on peak star formation of the Stelliferous Era and peak life.

The origins of civilization as we know it are contingent upon life as we known it, and life as we known it, as we have seen, is a function of the Stelliferous Era cosmos. However, civilization may be defined (among many other possible definitions) as life in possession of technological agency, and once life possesses technological agency it need not remain contingent upon the conditions of its origins. Some time ago in Human Beings: A Solar Species I addressed the idea that humanity is a solar species. Descriptively this is true at present, but it would be a logical fallacy to conflate the “is” of this present descriptive reality with an “ought” that prescribes out dependence upon our star, or even upon the system of stars that is the Stelliferous Era.

Civilization need not suffer from the End Stelliferous Mass Extinction Event as life must inevitably and eventually suffer. It could be argued that civilization as we know it (and, moreover, as defined above as “life in possession of technological agency”) is as contingent upon the conditions of the Stelliferous Era as is life as we known it. If we focus on the technological agency rather than upon life as we known it, even the far future of the universe offers amazing opportunities for civilization. The energy that we now derive from our star and from fossil fuels (itself a form of stored solar energy) we can derive on a far greater scale from angular momentum of rotating black holes (not mention other exotic forms of energy available to supercivilizations), and black holes and their resources will be available to civilizations even beyond the Degenerate Era following the Stelliferous Era, throughout the Black Hole Era.

Fred Adams and Greg Laughlin’s five ages of the universe.

In Addendum on Degenerate Era Civilization and Cosmology is the Principle of Plenitude teaching by Example I considered some of the interesting possibilities remaining for civilization during the Degenerate Era, and I pushed this perspective even further in my long Centauri Dreams post Who will read the Encyclopedia Galactica?

It is not until the Dark Era that the universe leaves civilization with no extractable energy resources, so that, if we have not by that time found our way to another, younger universe, it is the end of the Black Hole Era, and not the end of the Stelliferous Era, that will spell the doom of civilization. As black holes fade into nothingness one by one, much like stars at the end of the Stelliferous Era, the civilizations dependent upon them will wink out of existence, and this will be the End Civilization Mass Extinction Event (ECMEE) — but only if there is a mass of civilizations at this time to go extinct. This would mark the end of the apotheosis of emergent complexity.

The Apotheosis of Emergent Complexity

We can identify a period of time for our universe that we may call the apotheosis of emergent complexity, when stars are still forming, though on the decline, civilizations are only beginning to establish themselves in the cosmos, and life in the universe is at its peak. During this period, all of the forms of emergent complexity of which we are aware are simultaneously present, and the ecologies of galaxies, biospheres, and civilizations are all enmeshed each in the other.

It remains a possibility, perhaps even a likelihood, that further, unsuspected emergent complexities will grace the universe before its final dissolution in a heat death when the universe will be reduced to the thermodynamic equilibrium, which is the lowest common denominator of existence as we know it. Further forms of emergent complexity would require that we extend the framework I have suggested here, but, short of a robust and testable theory of the multiverse, which would extend the emergent complexity of stars, life, and civilizations to universes other than our own, the basic structure of the apotheosis of emergent complexity should remain as outlined above, even if extended by new forms.

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Parsimony in Copernicus and Osiander

Tuesday

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William of Ockham, one of the greatest philosophers of the late Middle Ages, is remembered today primarily for his formulation of the principle of parsimony, also called Ockham’s razor.

A medieval logician in the twenty-first century

In the discussion surrounding the unusual light curve of the star KIC 8462852, Ockham’s razor has been mentioned numerous times. I have written a couple of posts on this topic, i.e., interpreting the light curve of KIC 8462852 in light of Ockham’s razor, KIC 8462852 and Parsimony and Plenitude in Cosmology.

What is Ockham’s razor exactly? Well, that is a matter of philosophical dispute (and I offer my own more precise definition below), but even if it is difficult to say that Ockham’s razor is exactly, we can say something about what it was originally. Philotheus Boehner, a noted Ockham scholar, wrote of Ockham’s razor:

“It is quite often stated by Ockham in the form: ‘Plurality is not to be posited without necessity’ (Pluralitas non est ponenda sine necessitate), and also, though seldom: ‘What can be explained by the assumption of fewer things is vainly explained by the assumption of more things’ (Frustra fit per plura quod potest fieri per pauciora). The form usually given, ‘Entities must not be multiplied without necessity’ (Entia non sunt multiplicanda sine necessitate), does not seem to have been used by Ockham.”

William of Ockham, Philosophical Writings: A Selection, translated, with an Introduction, by Philotheus Boehner, O.F.M., Indianapolis and New York: The Library of Liberal Arts, THE BOBBS-MERRILL COMPANY, INC., 1964, Introduction, p. xxi

Most references to (and even most uses of) Ockham’s razor are informal and not very precise. In Maybe It’s Time To Stop Snickering About Aliens, which I linked to in KIC 8462852 Update, Adam Frank wrote of Ockham’s razor in relation to KIC 8462852:

“…aliens are always the last hypothesis you should consider. Occam’s razor tells scientists to always go for the simplest explanation for a new phenomenon. But even as we keep Mr. Occam’s razor in mind, there is something fundamentally new happening right now that all of us, including scientists, must begin considering… the exoplanet revolution means we’re developing capacities to stare deep into the light produced by hundreds of thousands of boring, ordinary stars. And these are exactly the kind of stars where life might form on orbiting planets… So we are already going to be looking at a lot of stars to hunt for planets. And when we find those planets, we are going to look at them for basic signs that life has formed. But all that effort means we will also be looking in exactly the right places to stumble on evidence of not just life but intelligent, technology-deploying life.

Here the idea of Ockham’s razor is present, but little more than the idea. Rather than merely invoking the idea of Ockham’s razor, and merely assuming what constitutes simplicity and parsimony, if we are going to profitably employ the idea today, we need to develop it more fully in the context of contemporary scientific knowledge. In KIC 8462852 I wrote:

“One can see an emerging adaptation of Ockham’s razor, such that explanations of astrophysical phenomena are first explained by known processes of nature before they are attributed to intelligence. Intelligence, too, is a process of nature, but it seems to be rare, so one ought to exercise particular caution in employing intelligence as an explanation.”

In a recent post, Parsimony and Emergent Complexity I went a bit further and suggested that Ockham’s razor can be formulated with greater precision in terms of emergent complexity, such that no phenomenon should be explained in terms of a level of emergent complexity higher than that necessary to explain the phenomenon.

De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres) is the seminal work on the heliocentric theory of the Renaissance astronomer Nicolaus Copernicus (1473–1543). The book, first printed in 1543 in Nuremberg, Holy Roman Empire, offered an alternative model of the universe to Ptolemy’s geocentric system, which had been widely accepted since ancient times. (Wikipedia)

De revolutionibus orbium coelestium and its textual history

Like Darwin many centuries later, Copernicus hesitated to publish his big book to explain his big idea, i.e., heliocentrism. Both men, Darwin and Copernicus, understood the impact that their ideas would have, though both probably underestimated the eventual influence of these ideas; both were to transform the world and leave as a legacy entire cosmologies. The particular details of the Copernican system are less significant than the Copernican idea, i.e., the Copernican cosmology, which, like Ockham’s razor, has gone on to a long career of continuing influence.

Darwin eventually published in his lifetime, prompted by the “Ternate essay” that Wallace sent him, but Copernicus put off publishing until the end of his life. It is said that Copernicus was shown a copy of the first edition of De revolutionibus on his deathbed (though this is probably apocryphal). Copernicus, of course, lived much closer to the medieval world than did Darwin — one could well argue that Toruń and Frombork in the fifteenth and sixteenth centuries was the medieval world — so we can readily understand Copernicus’ hesitation to publish. Darwin published in a world already transformed by industrialization, already wrenched by unprecedented social change; Copernicus eventually published in a world that, while on the brink of profound change, had not appreciably changed in a thousand years.

Copernicus’ hesitation meant that he did not directly supervise the publication of his manuscript, that he was not able to correct or revise subsequent editions (Darwin revised On the Origin of Species repeatedly for six distinct editions in his lifetime, not including translations), and that he was not able to respond to the reception of his book. All of these conditions were to prove significant in the reception and propagation of the Copernican heliocentric cosmology.

Copernicus, after long hesitation, was stimulated to pursue the publication of De revolutionibus by his contact with Georg Joachim Rheticus, who traveled to Frombork for the purpose of meeting Copernicus. Rheticus, who had great respect for Copernicus’ achievement, came from the hotbed of renaissance and Protestant scholarship that was Nuremberg. He took Copernicus’ manuscript to Nuremberg to be published by a noted scientific publisher of the day, but Rheticus did not stay to oversee the entire publication of the work. This job was handed down to Andreas Osiander, a Protestant theologian who sought to water down the potential impact of De Revolutionibus by adding a preface that suggested that Copernicus’ theory should be accepted in the spirit of an hypothesis employed for the convenience of calculation. Osiander did not sign this preface, and many readers of the book, when it eventually came out, thought that this preface was the authentic Copernican interpretation of the text.

Osiander’s preface, and Osiander’s intentions in writing the preface (and changing the title of the book) continue to be debated to the present day. This debate cannot be cleanly separated from the tumult surrounding the Protestant Reformation. Luther and the Lutherans were critical of Copernicus — they had staked the legitimacy of their movement on Biblical literalism — but one would have thought that Protestantism would have been friendly to the work of Ockham, given Ockham’s conflict with the Papacy, Ockham’s fideism, and his implicit position as a critic of Thomism. (I had intended to read up on the Protestant interpretation of Ockham prior to writing this post, but I haven’t yet gotten to this.) The parsimony of Copernicus’ formulation of cosmology, then, was a mixed message to the early scientific revolution in the context of the Protestant Reformation.

Both Rheticus and Copernicus’ friend Tiedemann Giese were indignant over the unsigned and unauthorized preface by Osiander. Rheticus, by some accounts, was furious, and felt that the book and Copernicus had been betrayed. He pursued legal action against the printer, but it is not clear that it was the printer who was at fault for the preface. While Rheticus suspected Osiander as the author of the preface, this was not confirmed until some time later, when Rheticus had moved on to other matters, so Osiander was never pursued legally over the preface.

Nicolaus Copernicus (1473–1543) — Mikołaj Kopernik in Polish, and Nikolaus Kopernikus in German

Copernicus’ Ockham

The most common reason adduced to preferring Copernican cosmology to Ptolematic cosmology is not that one is true and the other is false (though this certainly is a reason to prefer Copernicus) but rather that the Copernican cosmology is the simpler and more straight-forward explanation for the observed movements of the stars and the planets. The Ptolemaic system can predict the movements of stars, planets, and the moon (within errors of margin relevant to its time), but it does so by way of a much more complex and cumbersome method than that of Copernicus. Copernicus was radical in the disestablishment of traditional cosmological thought, but once beyond that first radical step of displacing the Earth of the center of the universe (a process we continue to iterate today), the solar system fell into place according to a marvelously simple plan that anyone could understand once it was explained: the sun at the center, and all the planets revolving around it. From the perspective of our rotating and orbiting Earth, the other planets also orbiting the sun appear to reverse in their course, but this is a mere artifact due to our position as observers. Once Copernicus can convince the reader that, despite the apparent solidity of the Earth, it is in fact moving through space, everything else falls into place.

One of the reasons that theoretical parsimony and elegance played such a significant role in the reception of Copernicus — and even the theologians who rejected his cosmology employed his calculations to clarify the calendar, so powerful was Copernicus’ work — was that the evidence given for the Copernican system was indirect. Even today, only a handful of the entire human population has ever left the planet Earth and looked down on it from above — seeing Earth from the perspective of the overview effect — and so acquired direct evidence of the Earth in space. No one, no single human being, has hovered above the solar system entire and looked down upon it and so obtained the most direct evidence of the Copernican theory — this is an overview affect that we have not yet attained. (NB: in The Scientific Imperative of Human Spaceflight I suggested the possibility of a hierarchy of overview effects as one moved further out from Earth.)

The knowledge that we have of our solar system, and indeed of the universe entire, is derived from observations and deduction from observations. Moreover, seeing the truth of Copernican heliocentrism would not only require an overview in space, but an overview in time, i.e., one would need to hover over our solar system for hundreds of years to see all the planets rotating around the common center of the sun, and one would have to, all the while, remain focused on observing the solar system in order to be able to have “seen” the entire process — a feat beyond the limitations of the human lifetime, not to mention human consciousness.

Copernicus himself did not mention the principle of parsimony or Ockham’s razor, and certainly did not mention William of Ockham, though Ockham was widely read in Copernicus’ time. The principle of parsimony is implicit, even pervasive, in Copernicus, as it is in all good science. We don’t want to account for the universe with Rube Goldberg-like contraptions as our explanations.

In a much later era of scientific thought — in the scientific thought of our own time — Stephen J. Gould wrote an essay titled “Is uniformitarianism necessary?” in which he argued for the view that uniformitarianism in geology had simply come to mean that geology follows the scientific method. Similarly, one might well argued that parsimony is no more necessary than uniformitarianism, and that what content of parsimony remains is simply coextenisve with the scientific method. To practice science is to reason in accordance with Ockham’s razor, but we need not explicitly invoke or apply Ockham’s razor, because its prescriptions are assimilated into the scientific method. And indeed this idea fits in quite well with the casual references to Ockham’s razor such as that I quoted above. Most scientists do not need to think long and hard about parsimony, because parsimonious formulations are already a feature of the scientific method. If you follow the scientific method, you will practice parsimony as a matter of course.

Copernicus’ Ockham, then, was already the Ockham already absorbed into nascent scientific thought. Perhaps it would be better to say that parsimony is implicit in the scientific method, and Copernicus, in implicitly following a scientific method that had not yet, in his time, been made explicit, was following the internal logic of the scientific method and its parsimonious demands for simplicity.

Andreas Osiander (19 December 1498 – 17 October 1552) was a German Lutheran theologian who oversaw the publication of Copernicus’ De revolutionibus and added an unsigned preface that many attributed to Copernicus.

Osiander’s Ockham

Osiander was bitterly criticized in his own time for his unauthorized preface to Copernicus, though many immediately recognized it as a gambit to allow for the reception of Copernicus’ work to involve the least amount of controversy. As I noted above, the Protestant Reformation was in full swing, and the events that would lead up the Thirty Years’ War were beginning to unfold. Europe was a powder keg, and many felt that it was the better part of valor not to touch a match to any issue that might explode. All the while, others were doing everything in their power to provoke a conflict that would settle matters once and for all.

Osiander not only added the unsigned and unauthorized preface, but also changed the title of the whole work from De revolutionibus to De revolutionibus orbium coelestium, adding a reference to the heavenly spheres that was not in Copernicus. This, too, can be understood as a concession to the intellectually conservative establishment — or it can be seen as a capitulation. But it was the preface, and what the preface claimed as the proper way to understand the work, that was the nub of the complaint against Osiander.

Here is a long extract of Osiander’s unsigned and unauthorized preface to De revolutionibus, not quite the whole thing, but most of it:

“…it is the duty of an astronomer to compose the history of the celestial motions through careful and expert study. Then he must conceive and devise the causes of these motions or hypotheses about them. Since he cannot in any way attain to the true causes, he will adopt whatever suppositions enable the motions to be computed correctly from the principles of geometry for the future as well as for the past. The present author has performed both these duties excellently. For these hypotheses need not be true nor even probable. On the contrary, if they provide a calculus consistent with the observations, that alone is enough. Perhaps there is someone who is so ignorant of geometry and optics that he regards the epicyclc of Venus as probable, or thinks that it is the reason why Venus sometimes precedes and sometimes follows the sun by forty degrees and even more. Is there anyone who is not aware that from this assumption it necessarily follows that the diameter of the planet at perigee should appear more than four times, and the body of the planet more than sixteen times, as great as at apogee? Yet this variation is refuted by the experience of every age. In this science there are some other no less important absurdities, which need not be set forth at the moment. For this art, it is quite clear, is completely and absolutely ignorant of the causes of the apparent nonuniform motions. And if any causes are devised by the imagination, as indeed very many are, they are not put forward to convince anyone that are true, but merely to provide a reliable basis for computation. However, since different hypotheses are sometimes offered for one and the same motion (for example, eccentricity and an epicycle for the sun’s motion), the astronomer will take as his first choice that hypothesis which is the easiest to grasp. The philosopher will perhaps rather seek the semblance of the truth. But neither of them will understand or state anything certain, unless it has been divinely revealed to him.”

Nicholas Copernicus, On the Revolutions, Translation and Commentary by Edward Rosen, THE JOHNS HOPKINS UNIVERSITY PRESS, Baltimore and London

If we eliminate the final qualification, “unless it has been divinely revealed to him,” Osiander’s preface is a straight-forward argument for instrumentalism. Osiander recommends Copernicus’ work because it gives the right results; we can stop there, and need not make any metaphysical claims on behalf of the theory. This ought to sound very familiar to the modern reader, because this kind of instrumentalism has been common in positivist thought, and especially so since the advent of quantum theory. Quantum theory is the most thoroughly confirmed theory in the history of science, confirmed to a degree of precision almost beyond comprehension. And yet quantum theory still lacks an intuitive correlate. Thus we use quantum theory because it gives us the right results, but many scientists hesitate to give any metaphysical interpretation to the theory.

Copernicus, and those most convinced of his theory, like Rheticus, was a staunch scientific realist. He did not propose his cosmology as a mere system of calculation, but insisted that his theory was the true theory describing the motions of the planets around the sun. It follows from this uncompromising scientific realism that other theories are not merely less precise in calculating the movements of the planets, but false. Scientific realism accords with common sense realism when it comes to the idea that there is a correct account of the world, and other accounts that deviate from the correct account are false. But we all know that scientific theories are underdetermined by the evidence. To formulate a law is to go beyond the finite evidence and to be able to predict an infinitude of possible future states of the phenomenon predicted.

Scientific realism, then, is an ontologically robust position, and this ontological robustness is a function of the underdetermination of the theory by the evidence. Osiander argues of Copernicus’ theory that, “if they provide a calculus consistent with the observations, that alone is enough.” So Osiander is not willing to go beyond the evidence and posit the truth of an underdetermined theory. Moreover, Osiander was willing to maintain empirically equivalent theories, “since different hypotheses are sometimes offered for one and the same motion.” Given empirically equivalent theories that can both “provide a calculus consistent with the observations,” why would one theory be favored over another? Osiander states that the astronomer will prefer the simplest explanation (hence explaining Copernicus’ position) while the philosopher will seek a semblance of truth. Neither, however, can know what this truth is without divine revelation.

Osiander’s Ockham is the convenience of the astronomer to seek the simplest explanation for his calculations; the astronomer is justified in employing the simplest explanation of the most precise method available to calculate and predict the course of the heavens, but he cannot know the truth of his theory unless that truth is guaranteed by some outside and transcendent evidence not available through science — a deus ex machina for the mind.

Copernicus stands at the beginning of the scientific revolution, and he stands virtually alone.

The origins of the scientific revolution in Copernicus

Copernicus’ Ockham was ontological parsimony; Osiander’s Ockham was methodological parsimony. Are we forced to choose between the two, or are we forced to find a balance between ontological and methodological parsimony? These are still living questions in the philosophy of science today, and there is a sense in which it is astonishing that they appeared so early in the scientific revolution.

As noted above, the world of Copernicus was essentially a medieval world. Toruń and Frombork were far from the medieval centers of learning in Paris and Oxford, and about as far from the renaissance centers of learning in Florence and Nuremberg. Nevertheless, the new cosmology that emerged from the scientific revolution, and which is still our cosmology today, continuously revised and improved, can be traced to the Baltic coast of Poland in the late fifteenth and early sixteenth century. The controversy over how to interpret the findings of science can be traced to the same root.

The conventions of the scientific method were established in the work of Copernicus, Galileo, and Newton, which means that it was the work of these seminal thinkers who established these conventions. Like the cosmologies of Copernicus, Galileo, and Newton, the scientific method has also been continuously revised and improved. That Copernicus grasped in essence as much of the scientific method as he did, working in near isolation far from intellectual centers of western civilization, demonstrates both the power of Copernicus’ mind and the power of the scientific method itself. As implied above, once grasped, the scientific method has an internal logic of its own that directs the development of scientific thought.

The scientific method — methodological naturalism — exists in an uneasy partnership with scientific realism — ontological naturalism. We can see that this tension was present right from the very beginning of the scientific revolution, before the scientific method was ever formulated, and the tension continues down to the present day. Contemporary analytical philosophers discuss the questions of scientific realism in highly technical terms, but it is still the same debate that began with Copernicus, Rheticus, and Osiander. Perhaps we can count the tension between methodological naturalism and ontological naturalism as one of the fundamental tensions of scientific civilization.

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Updates and Addenda

This post began as a single sentence in one of my note books, and continued to grow as I worked on it. As soon as I posted it I realized that the discussions of scientific realism, instrumentalism, and methodological naturalism in relation to parsimony could be much better. With additional historical and philosophical discussion, this post might well be transformed into an entire book. So for the questioning reader, yes, I understand the inadequacy of what I have written above, and that I have not done justice to my topic.

Shortly after posting the above Paul Carr pointed out to me that the joint ESA-NASA Ulysses deep-space mission sent a spacecraft to study the poles of the sun, so we have sent a spacecraft out of the plane of the solar system, which could “look down” on our star and its planetary system, although the mission was not designed for this and had no cameras on board. If we did position a camera “above” our solar system, it would be able to take pictures of our heliocentric solar system. This, however, would be more indirect evidence — more direct than deductions from observations, but not as direct as seeing this with one’s own eyes — like the famous picture of the “blue marble” Earth, which is an overview experience for those of us who have not been into orbit to the moon, but which is not quite the same as going into orbit or to the moon.

Paul Carr also drew my attention to Astronomy Cast Episode 390: Occam’s Razor and the Problem with Probabilities, with Fraser Cain and Pamela Gay, which discusses Ockham’s razor in relation to positing aliens as a scientific explanation.

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A Brief History of the Stelliferous Era

Friday

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Fred Adams and Greg Laughlin’s five ages of the universe

Introduction: Periodization in Cosmology

Recently Paul Gilster has posted my Who will read the Encyclopedia Galactica? on his Centauri Dreams blog. In this post I employ the framework of Fred Adams and Greg Laughlin from their book The Five Ages of the Universe: Inside the Physics of Eternity, who distinguish the Primordial Era, before stars have formed, the Stelliferous Era, which is populated by stars, the Degenerate Era, when only the degenerate remains of stars are to be found, the Black Hole Era, when only black holes remain, and finally the Dark Era, when even black holes have evaporated. These major divisions of cosmological history allow us to partition the vast stretches of cosmological time, but it also invites us to subdivide each era into smaller increments (such is the historian’s passion for periodization).

The Stelliferous Era is the most important to us, because we find ourselves living in the Stelliferous Era, and moreover everything that we understand in terms of life and civilization is contingent upon a biosphere on the surface of a planet warmed by a star. When stellar formation has ceased and the last star in the universe burns out, planets will go dark (unless artificially lighted by advanced civilizations) and any remaining biospheres will cease to function. Life and civilization as we know it will be over. I have called this the End-Stelliferous Mass Extinction Event.

It will be a long time before the end of the Stelliferous Era — in human terms, unimaginably long. Even in scientific terms, the time scale of cosmology is long. It would make sense for us, then, to break up the Stelliferous Era into smaller periodizations that can be dealt with each in turn. Adams and Laughlin constructed a logarithmic time scale based on powers of ten, calling each of these powers of ten a “cosmological decade.” The Stelliferous Era comprises cosmological decades 7 to 15, so we can further break down the Stelliferous Era into three divisions of three cosmological decades each, so cosmological decades 7-9 will be the Early Stelliferous, cosmological decades 10-12 will be the Middle Stelliferous, and cosmological decades 13-15 will be the late Stelliferous.

The Early Stelliferous

Another Big History periodization that has been employed other than that of Adams of Laughlin is Eric Chaisson’s tripartite distinction between the Energy Era, the Matter Era, and the Life Era. The Primordial Era and the Energy Era coincide until the transition point (or, if you like, the phase transition) when the energies released by the big bang coalesce into matter. This phase transition is the transition from the Energy Era to the Matter Era in Chaisson; for Adams and Laughlin this transition is wholly contained within the Primordial Era and may be considered one of the major events of the Primorial Era. This phase transition occurs at about the fifth cosmological decade, so that there is one cosmological decade of matter prior to that matter forming stars.

At the beginning of the Early Stelliferous the first stars coalesce from matter, which has now cooled to the point that this becomes possible for the first time in cosmological history. The only matter available at this time to form stars is hydrogen and helium produced by the big bang. The first generation of stars to light up after the big bang are called Population III stars, and their existence can only be hypothesized because no certain observations exist of Population III stars. The oldest known star, HD 140283, sometimes called the Methuselah Star, is believed to be a Population II star, and is said to be metal poor, or of low metallicity. To an astrophysicist, any element other than hydrogen or helium is a “metal,” and the spectra of stars are examined for the “metals” present to determine their order of appearance in galactic ecology.

The youngest stars, like our sun and other stars in the spiral arms of the Milky Way, are Population I stars and are rich in metals. The whole history of the universe up to the present is necessary to produce the high metallicity younger stars, and these younger stars form from dust and gas that coalesce into a protoplanetary disk surrounding the young star of similarly high metal content. We can think of the stages of Population III, Population II, and Population I stars as the evolutionary stages of galactic ecology that have produced structures of greater complexity. Repeated cycles of stellar nucleosynthesis, catastrophic supernovae, and new star formation from these remnants have produced the later, younger stars of high metallcity.

It is the high relative proportion of heavier elements that makes possible the formulation of small rocky planets in the habitable zone of a stable star. The minerals that form these rocky planets are the result of what Robert Hazen calls minerological evolution, which we may consider to be an extension of galactic ecology on a smaller scale. These planets, in turn, have heavier elements distributed throughout their crust, which, in the case of Earth, human civilization has dug out of the crust and put to work manufacturing the implements of industrial-technological civilization. If Population II and Population III stars had planets (this is an open area of research in planet formation and without a definite answer as yet), it is conceivable that these planets might have harbored life, but the life on such worlds would not have had access to heavier elements, so any civilization that resulted would have had a difficult time of it creating an industrial or electrical technology.

The Middle Stelliferous

In the Middle Stelliferous, the processes of galactic ecology that produced and which now sustain the Stelliferous Era have come to maturity. There is a wide range of galaxies consisting of a wide range of stars, running the gamut of the Hertzsprung–Russell diagram. It is a time of both galactic and stellar prolixity, diversity, and fecundity. But even as the processes of galactic ecology reach their maturity, they begin to reveal the dissipation and dissolution that will characterize the Late Stelliferous Era and even the Degenerate Era to follow.

The Milky Way, which is a very old galaxy, carries with it the traces of the smaller galaxies that it has already absorbed in its earlier history — as, for example, the Helmi Stream — and for the residents of the Milky Way and Andromeda galaxies one of the most spectacular events of the Middle Stelliferous Era will be the merging of these two galaxies in a slow-motion collision taking place over millions of years, throwing some star systems entirely clear of the newly merged galaxies, and eventually resulting in the merging of the supermassive black holes that anchor the centers of each of these elegant spiral galaxies. The result is likely to be an elliptical galaxy not clearly resembling either predecessor (and sometimes called the Milkomeda).

Eventually the Triangulum galaxy — the other large spiral galaxy in the local group — will also be absorbed into this swollen mass of stars. In terms of the cosmological time scales here under consideration, all of this happens rather quickly, as does also the isolation of each of these merged local groups which persist as lone galaxies, suspended like a island universe with no other galaxies available to observational cosmology. The vast majority of the history of the universe will take place after these events have transpired and are left in the long distant past — hopefully not forgotten, but possibly lost and unrecoverable.

The Tenth Decade

The tenth cosmological decade, comprising the years between 10¹⁰ to 10¹¹ (10,000,000,000 to 100,000,000,000 years, or 10 Ga. to 100 Ga.) since the big bang, is especially interesting to us, like the Stelliferous Era on the whole, because this is where we find ourselves. Because of this we are subject to observation selection effects, and we must be particularly on guard for cognitive biases that grow out of the observational selection effects we experience. Just as it seems, when we look out into the universe, that we are in the center of everything, and all the galaxies are racing away from us as the universe expands, so too it seems that we are situated in the center of time, with a vast eternity preceding us and a vast eternity following us.

Almost everything that seems of interest to us in the cosmos occurs within the tenth decade. It is arguable (though not definitive) that no advanced intelligence or technological civilization could have evolved prior to the tenth decade. This is in part due to the need to synthesize the heavier elements — we could not have developed nuclear technology had it not been for naturally occurring uranium, and it is radioactive decay of uranium in Earth’s crust that contributes significantly to the temperature of Earth’s core and hence to Earth being a geologically active planet. By the end of the tenth decade, all galaxies will have become isolated as “island universes” (once upon a time the cosmological model for our universe today) and the “end of cosmology” (as Krauss and Sherrer put it) will be upon us because observational cosmology will no longer be able to study the large scale structures of the universe.

The tenth decade, thus, is not only when it becomes possible for an intelligent species to evolve, to establish an industrial-technological civilization on the basis of heavier elements built up through nucleosynthesis and supernova explosions, and to employ these resources to launch itself as a spacefaring civilization, but also this is the only period in the history of the universe when such a spacefaring civilization can gain a true foothold in the cosmos to establish an intergalactic civilization. After local galactic groups coalesce into enormous single galaxies, and all other similarly coalesced galaxies have passed beyond the cosmological horizon and can no longer be observed, an intergalactic civilization is no longer possible on principles of science and technology as we understand them today.

It is sometimes said that, for astronomers, galaxies are the basic building blocks of the universe. The uniqueness of the tenth decade, then, can be expressed as being the only time in cosmological history during which a spacefaring civilization can emerge and then can go on to assimilate and unify the basic building blocks of the universe. It may well happen that, by the time of million year old supercivilizations and even billion year old supercivilizations, sciences and technologies will have been developed far beyond our understanding that is possible today, and some form of intergalactic relationship may continue after the end of observational cosmology, but, if this is the case, the continued intergalactic organization must be on principles not known to us today.

The Late Stelliferous

In the Late Stelliferous Era, after the end of the cosmology, each isolated local galactic group, now merged into a single giant assemblage of stars, will continue its processes of star formation and evolution, ever so slowly using up all the hydrogen produced in the big bang. The Late Stelliferous Era is a universe having passed “Peak Hydrogen” and which can therefore only look forward to the running down of the processes of galactic ecology that have sustained the universe up to this time.

The end of cosmology will mean a changed structure of galactic ecology. Even if civilizations can find a way around their cosmological isolation through advanced technology, the processes of nature will still be bound by familiar laws of nature, which, being highly rigid, will not have changed appreciably even over billions of years of cosmological evolution. Where light cannot travel, matter cannot travel either, and so any tenuous material connection between galactic groups will cease to play any role in galactic ecology.

The largest scale structures that we know of in the universe today — superclusters and filaments — will continue to expand and cool and to dissipate. We can imagine a bird’s eye view of the future universe (if only a bird could fly over the universe entire), with its large scale structures no longer in touch with one another but still constituting the structure, rarified by expansion, stretched by gravity, and subject to the evolutionary processes of the universe. This future universe (which we may have to stop calling the universe, as it is lost its unity) stands in relation to its current structure as the isolated and strung out continents of Earth today stand in relation to earlier continental structures (such as the last supercontinent, Pangaea), preceding the present disposition of continents (though keep in mind that there have been at least five supercontinent cycles since the formation of Earth and the initiation of its tectonic processes).

Near the end of the Stelliferous Era, there is no longer any free hydrogen to be gathered together by gravity into new suns. Star formation ceases. At this point, the fate of the brilliantly shining universe of stars and galaxies is sealed; the Stelliferous Era has arrived at functional extinction, i.e., the population of late Stelliferous Era stars continues to shine but is no longer viable. Galactic ecology has shut down. Once star formation ceases, it is only a matter of time before the last of the stars to form burn themselves out. Stars can be very large, very bright and short lived, or very small, scarcely a star at all, very dim, cool, and consequently very long lived. Red dwarf stars will continue to burn dimly long after all the main sequence stars like the sun have burned themselves out, but eventually even the dwarf stars, burning through their available fuel at a miserly rate, will burn out also.

The Post-Stelliferous Era

After the Stelliferous Era comes the Degenerate Era, with the two eras separated by what I have called the Post-Stelliferous Mass Extinction Event. What the prospects are for continued life and intelligence in the Degenerate Era is something that I have considered in Who will read the Encyclopedia Galactica? and Addendum on Degenerate Era civilization, inter alia.

Our enormous and isolated galaxy will not be immediately plunged into absolute darkness. Adams and Laughlin (referred to above) estimate that our galaxy may have about a hundred small stars shining — the result of the collision of two or more brown dwarfs. Brown dwarf stars, at this point in the history of the cosmos, contain what little hydrogen remains, since brown dwarf stars were not large enough to initiate fusion during the Stelliferous Era. However, if two or more brown dwarfs collide — a rare event, but in the vast stretches of time in the future of the universe rare events will happen eventually — they may form a new small star that will light up like a dim candle in a dark room. There is a certain melancholy grandeur in attempting to imagine a hundred or so dim stars strewn through the galaxy, providing a dim glow by which to view this strange and unfamiliar world.

Our ability even to outline the large scale structures — spatial, temporal, biological, technological, intellectual, etc. — of the extremely distant future is severely constrained by our paucity of knowledge. However, if terrestrial industrial-technological civilization successfully makes the transition to being a viable spacefaring civilization (what I might call extraterrestrial-spacefaring civilization) our scientific knowledge of the universe is likely to experience an exponential inflection point surpassing the scientific revolution of the early modern period.

An exponential improvement in scientific knowledge (supported on an industrial-technological base broader than the surface of a single planet) will help to bring the extremely distant future into better focus and will give to our existential risk mitigation efforts both the knowledge that such efforts requires and the technological capability needed to ensure the perpetual ongoing extrapolation of complexity driven by intelligent, conscious, and purposeful intervention in the world. And if not us, if not terrestrial civilization, then some other civilization will take over the mantle and the far future will belong to them.

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Cosmology: Constructive and Non-Constructive

Wednesday

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Immanuel Kant, in an often-quoted passage, spoke of, “…the starry heavens above me and the moral law within me.” Kant might have with equal justification spoken of the formal law within and the starry heavens above. There is a sense in which the formal laws of thought are the moral laws of the mind — in logic, a good thought is a rigorous thought — so that given sufficient latitude of translation, we can interpret Kant in this way — except that we know (as Nietzsche put it) that Kant was a moral fanatic à la Rousseau.

However we choose to interpret Kant, I would like to quote more fully from the passage in the Critique of Practical Reason where Kant invokes the starry heavens above and the moral law within:

“Two things fill the mind with ever new and increasing admiration and awe, the oftener and the more steadily we reflect on them: the starry heavens above and the moral law within. I have not to search for them and conjecture them as though they were veiled in darkness or were in the transcendent region beyond my horizon; I see them before me and connect them directly with the consciousness of my existence. The former begins from the place I occupy in the external world of sense, and enlarges my connection therein to an unbounded extent with worlds upon worlds and systems of systems, and moreover into limitless times of their periodic motion, its beginning and continuance. The second begins from my invisible self, my personality, and exhibits me in a world which has true infinity, but which is traceable only by the understanding, and with which I discern that I am not in a merely contingent but in a universal and necessary connection, as I am also thereby with all those visible worlds. The former view of a countless multitude of worlds annihilates as it were my importance as an animal creature, which after it has been for a short time provided with vital power, one knows not how, must again give back the matter of which it was formed to the planet it inhabits (a mere speck in the universe). The second, on the contrary, infinitely elevates my worth as an intelligence by my personality, in which the moral law reveals to me a life independent of animality and even of the whole sensible world, at least so far as may be inferred from the destination assigned to my existence by this law, a destination not restricted to conditions and limits of this life, but reaching into the infinite.”

Immanuel Kant, Critique of Practical Reason, 1788, translated by Thomas Kingsmill Abbott, Part 2, Conclusion

This passage is striking for many reasons, not least among them them degree to which Kant has assimilated the Copernican revolution, acknowledging Earth as a mere speck in the universe. Also particularly interesting is Kant’s implicit appeal to objectivity and realism, notwithstanding the fact that Kant himself established the tradition of transcendental idealism. Kant in this passage invokes the starry heavens above and the moral law within because they are independent of the individual …

Moreover, Kant identifies both the starry heavens above and the moral law within not only as objective and independent realities, but also as infinitistic. Just as Kant the idealist looks to the stars and the moral law in a realistic spirit, so Kant the proto-constructivist invokes the “…unbounded extent with worlds upon worlds” of the starry heavens and the moral law as, “…reaching into the infinite.” I have earlier and elsewhere observed how Kant’s proto-constructivism nevertheless involves spectacularly non-constructive arguments. In the passage quoted above both Kant’s proto-constructivism and his non-constructive moments are retained in lines such as, “exhibits me in a world which has true infinity,” which by invoking exhibition in intuition toes the constructivist line, while invoking true infinity allows a legitimate role for the non-constructive.

When it comes to constructivism, we can see that Kant is conflicted. He’s not the only one. One might call Aristotle the first constructivist (or, at least, the first proto-constructivist) as the originator of the idea of the potential infinite, and here (i.e., in the context of the above discussion of Kant’s use of the infinite) Aristotelian permissive finitism is particularly relevant. (Aristotle would likely not have had much sympathy for intuitionistic constructivism, which its rejection of tertium non datur.)

The Greek intellectual attitude to the infinite was complex and conflicted. I have written about this previously in Reason in Moderation and Salto Mortale. The Greek quest for harmony, order, and proportion rejected the infinite as something that transgresses the boundaries of good taste and propriety (dismissing the infinite as apeiron, in contradistinction to peras). Nevertheless, Greek philosophers routinely argued from the infinity and eternity of the world.

Here is a famous passage from Democritus, who was perhaps best known among the Greek philosophers in arguing for the infinity of the world, making the doctrine a virtual tenet among ancient atomists:

“Worlds are unlimited and of different sizes. In some worlds there is no Sun and Moon, in others, they are larger than in our world, and in others more numerous. … Intervals between worlds are unequal. In some parts there are more worlds, in others fewer; some are increasing, some at their height, some decreasing; in some parts they are arising, in others failing… There are some worlds devoid of living creatures or plants or any moisture.”

Democritus, Fragments

…and Epicurus on the same theme of the infinity of the world…

“…there is an infinite number of worlds, some like this world, others unlike it. For the atoms being infinite in number, as has just been proved, are borne ever further in their course. For the atoms out of which a world might arise, or by which a world might be formed, have not all been expended on one world or a finite number of worlds, whether like or unlike this one. Hence there will be nothing to hinder an infinity of worlds.”

Epicurus, Letter to Herodotus

There were also poetic invocations of the idea of the infinity of the world, which demonstrates the extent to which the idea had penetrated popular consciousness in classical antiquity:

“When Alexander heard from Anaxarchus of the infinite number of worlds, he wept, and when his friends asked him what was the matter, he replied, ‘Is it not a matter for tears that, when the number of worlds is infinite, I have not conquered one?'”

Plutarch, PLUTARCH’S MORALS, ETHICAL ESSAYS TRANSLATED WITH NOTES AND INDEX BY ARTHUR RICHARD SHILLETO, M.A., Sometime Scholar of Trinity College, Cambridge, Translator of Pausanias, LONDON: GEORGE BELL AND SONS, 1898, “On Contentedness of Mind,” section IV

Like poetry, history had particular prestige in the ancient world, and here the theme of the infinity of the world also occurs:

“…Constantius, elated by this extravagant passion for flattery, and confidently believing that from now on he would be free from every mortal ill, swerved swiftly aside from just conduct so immoderately that sometimes in dictation he signed himself ‘My Eternity,’ and in writing with his own hand called himself lord of the whole world — an expression which, if used by others, ought to have been received with just indignation by one who, as he often asserted, laboured with extreme care to model his life and character in rivalry with those of the constitutional emperors. For even if he ruled the infinity of worlds postulated by Democritus, of which Alexander the Great dreamed under the stimulus of Anaxarchus, yet from reading or hearsay he should have considered that (as the astronomers unanimously teach) the circuit of whole earth, which to us seems endless, compared with the greatness of the universe has the likeness of a mere tiny point.

Ammianus Marcellinus, Roman Antiquities, Book XV, section 1

Like the quote from Kant quoted above, this passage is remarkable for its Copernican outlook, which shows that the ancients were not only capable of thinking in infinitistic terms, but also in more-or-less Copernican terms.

Lucretius was a follower of Epicurus, and gave one of the more detailed arguments for the infinity of the world to be found in ancient philosophy:

It matters nothing where thou post thyself,
In whatsoever regions of the same;
Even any place a man has set him down
Still leaves about him the unbounded all
Outward in all directions; or, supposing
moment the all of space finite to be,
If some one farthest traveller runs forth
Unto the extreme coasts and throws ahead
A flying spear, is’t then thy wish to think
It goes, hurled off amain, to where ’twas sent
And shoots afar, or that some object there
Can thwart and stop it? For the one or other
Thou must admit; and take. Either of which
Shuts off escape for thee, and does compel
That thou concede the all spreads everywhere,
Owning no confines. Since whether there be
Aught that may block and check it so it comes
Not where ’twas sent, nor lodges in its goal,
Or whether borne along, in either view
‘Thas started not from any end. And so
I’ll follow on, and whereso’er thou set
The extreme coasts, I’ll query, “what becomes
Thereafter of thy spear?” ‘Twill come to pass
That nowhere can a world’s-end be, and that
The chance for further flight prolongs forever
The flight itself. Besides, were all the space
Of the totality and sum shut in
With fixed coasts, and bounded everywhere,
Then would the abundance of world’s matter flow
Together by solid weight from everywhere
Still downward to the bottom of the world,
Nor aught could happen under cope of sky,
Nor could there be a sky at all or sun-
Indeed, where matter all one heap would lie,
By having settled during infinite time.

Lucretius, De rerum natura

The above argument is one that is still likely to be heard today, in various forms. If you go to the edge of the universe and throw a spear, either it is stopped by the boundary of the universe, or it continues on, and, as Lucretius says, For the one or other, Thou must admit. If the spear is stopped, what stopped it? And if it continues on, into what does it continue?

The contemporary relativistic cosmology has a novel answer to this ancient idea: the universe is finite and unbounded, so that space is wrapped back around on itself. What this means for the spear-thrower at the edge of the universe is that if he throws the spear with enough force, it may travel around the cosmos and return to pierce him in the back. There is nothing to stop the spear, because the universe is unbounded, but since the universe is also finite the spear will eventually cross its own path if it continues to travel. I do not myself think that the universe is finite and unbounded in precisely the way the many modern cosmologists argue, but I am not going to go into this interesting problem at the present time.

Other than the response to Lucretius in terms of relativistic cosmology, with its curved spacetime — a material response to the Lucretian argument for the infinity of the world — there is another response, that of intuitionistic constructivism, which denies the law of the excluded middle (tertium non datur) — i.e, a formal response to Lucretius. Lucretius asserted that, For the one or other, Thou must admit, and this is exactly what the intuitionist does not admit. As with the relativistic response to Lucretius, I do not myself agree with the intuitionist response to Lucretius. Consequently, I believe that Lucretius argument is still valid in spirit, though it must be reformulated in order to be applicable to the world as revealed to us by contemporary science. Consequently, I take it as demonstrable that the universe is infinite, taking the view of ancient natural philosophers.

Within the overall context of Greek thought, within its contending finitist and infinitistic strains, Greek cosmology was non-constructive, and the Greeks asserted (and argued for) the infinity of the world on the basis of non-constructive argument. Perhaps it would even be fair to say that the Greeks assumed the universe to be infinite in extent, and they at times sought to justify this assumption by philosophical argument, while at other times they confined themselves to the sphere of the peras.

Much of contemporary science is constructivist in spirit, though this constructivism is rarely made explicit, except among logicians and mathematicians. By this I mean that the general drift of science ever since the scientific revolution has been toward bottom-up constructions on the basis of quantifiable evidence and away from top-down argument. I made this point previously in Advanced Thinking and A Non-Constructive World, as well as other posts, though I haven’t yet given a detailed formulation of this idea. Yet the emergence of a “quantum logic” in quantum theory that does away with the principle of the excluded middle is a clear expression of the increasing constructivism of science.

In A Non-Constructive World I also made the point that the world appears to have both constructive and non-constructive features. In several posts about constructivism (e.g., P or not-P) I have argued that constructivism and non-constructivism are complementary perspectives on formal thought, and that each needs the other for an adequate account of the world.

In so far as contemporary science is essentially constructive, it lacks a non-constructive perspective on the phenomena it investigates. This is, I believe, intrinsic to science, and to the kind of civilization that emerges from the application of science to the economy (viz. industrial-technological civilization). By the constructive methods of science we can attain ever larger and ever more comprehensive conceptions of the universe — such as I described in my previous post, The Size of the World — but these constructive methods will never reach the infinite universe contemplated by the ancient Greeks.

How could the logical framework employed by a scientist have any effect over what they see in the heavens? Well, constructive science is logically incapable of formulating the idea of an infinite universe in any sense other than an Aristotelian potential infinite. No one can observe the infinite (in the philosophy of mathematics we say that the infinite is “unsurveyable”). And if you cannot produce observational evidence of the infinite, then you cannot formulate a falsifiable theory of an infinite universe. Thus the infinity of the world is, in effect, ruled out by our methods.

No one should be surprised at the direct impact the ethos of formal thought has a upon the natural sciences; one of the fundamental trends of the scientific revolution has been the mathematization of natural science, and one of the fundamental trends of mathematical rigor since the late nineteenth century has been the arithmetization of analysis, which has been taken as far as the logicization of mathematics. Logic and mathematics have been “finitized” and these finite formal methods have been employed in the rational reconstruction of the sciences.

I look forward to the day when the precision and rigor of formal methods employed in the natural sciences again includes infinitistic methods, and it once again becomes possible to formulate the thesis of the infinity of the world in science — and possible once again to see the world as infinite.

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The Size of the World

Sunday

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The Sloan Digital Sky Survey points to a large scale structure of the universe dominated by hyperclusters, which appear to be structures that exceed the upper size limit of structures as predicted by contemporary cosmology.

The world, we are learning every day, is a very large place. Or perhaps I should say that the universe is a very large place. It is also a very complex and strange place. J. B. S. Haldane famously said that, “I have no doubt that in reality the future will be vastly more surprising than anything I can imagine. Now my own suspicion is that the Universe is not only queerer than we suppose, but queerer than we can suppose.” (Possible Worlds and Other Papers, 1927, p. 286) In other words, human beings, no matter how valiantly they attempt to understand the universe, may not be cognitively equipped to understand it; our minds may not be the kind of minds that can understand the kind of place that the world is.

This idea of our inability to understand the world in which we find ourselves (an admirably humble Copernican insight that we might call metaphysical modesty, and which stands in contrast to epistemic hubris) has received many glosses since Haldane’s time. Most notable (notable, at least, from my perspective) are the evolutionary gloss, the quantum physics gloss, and the philosophical gloss. I will consider each of these in turn.

In terms of evolution, there is no reason to suppose that descent with modification in a context of a struggle for vital resources on the plains of Africa (the environment of evolutionary adaptedness, or EEA) is going to produce minds capable of understanding higher dimensional spatial manifolds or quantum physics at microscopic scales that differ radically from the macroscopic scales of ordinary human perception. Alvin Plantinga (about whom I wrote some time ago in A Note on Plantinga, inter alia) has used this argument for theological purposes. However, there is no intrinsic reason that a mind born in the mud and the muck cannot raise itself above its origins and come to contemplate the world in Copernican terms. The evolutionary argument cuts both ways, and since we have ourselves as the evidence of an organism that can raise itself from strictly survival behavior to forms of thought that have nothing to do with survival, from the perspective of the weak anthropic principle this is proof enough that natural selection can result in such a mind.

In terms of quantum theory, we are all familiar with famous quotes from the leading lights of quantum theory as to the essentially incomprehensibility of that theory. For example, Richard Feynman said, “I think I can safely say that nobody understands quantum mechanics.” However, I have observed (in The limits of my language are the limits of my world and elsewhere) that recent research is making strides in working around the epistemic limitations of quantum theory, revealing its uncertainties to be not absolute and categorical, but rather subject to careful and painstaking narrowing that renders the uncertainty a little less uncertain. I anticipate two developments that will emerge from the further elaborate of quantum theory: 1) the finding of ways to gradually and incrementally chip away at an absolutist conception of uncertainty (as just mentioned), and 2) the formulation of more adequate intuitions to make quantum theory more palatable to the human mind.

In terms of philosophy, Colin McGinn’s book Problems in philosophy: The Limits of Inquiry formulates a position which he calls Transcendental Naturalism:

“Philosophy is an attempt to get outside the constitutive structure of our minds. Reality itself is everywhere flatly natural, but because of our cognitive limits we are unable to make good on this general ontological principle. Our epistemic architecture obstructs knowledge of the real nature of the objective world. I shall call this thesis transcendental naturalism, TN for short.” (pp. 2-3)

I have previously written about McGinn’s work in Transcendental Non-Naturalism and Naturalism and Object Oriented Ontology, inter alia. Our ability to get outside the constitutive structure of our minds is severely limited at best, and so our ability to understand the world as it is is limited at best.

While our cognitive abilities are admittedly limited (for all the reasons discussed above, as well as other reasons not discussed), these limits are not absolute, but rather admit of revision. McGinn’s position as stated above implies a false dichotomy between staying within the constitutive structure of our minds and getting outside it. This is a classic case of facing the sheer cliff of Mount Improbable: while it is impossible to get outside our cognitive architecture in one fell swoop, we can little by little transgress the boundaries of our cognitive architecture, each time ever-so-slightly expanding our capacities. Incrementally over time we improve our ability to stand outside those limits that once marked the boundaries of our cognitive architecture. Thus in an ironic twist of intellectual history, the evolutionary argument, rather than demonstrating metaphysical modesty, is rather the key to limiting the limitations on the human mind.

All of this is related to one of the central problems in the philosophy of science of our time — the whole Kuhnian legacy that is the framework of so much contemporary philosophy of science. Copernican revelations and revolutions, which formerly disturbed our anthropocentric bias every few hundred years, now occur with alarming frequency. The difference today, of course, is that science is much more advanced than it was with past Copernican revelations and revolutions — it has much more advanced instrumentation available to it (as a result of the STEM cycle), and we have a much better idea of what to look for in the cosmos.

It was a shock to almost everyone to have it scientifically demonstrated that the universe is not static and eternal, but dynamic and changing. It was a shock when quantum theory demonstrated the world to be fundamentally indeterministic. This is by now a very familiar narrative. In fact, it is so familiar that it has been expropriated (dare I say exapted?) by obscurantists and irrationalists of our time, who point at continual changes at scientific knowledge as “proof” that science doesn’t give us any “truth” because it changes. The assumption here is that change in scientific knowledge demonstrates the weakness of science; in fact, change in scientific knowledge is the strength of science. Scientific knowledge is what I have elsewhere called an intelligent institution in so far as it is institutionalized knowledge, but that institution is formulated with internal mechanisms that facilitate the re-shaping of the institution itself over time. That mechanism is the scientific method.

It is important to see that the overturning of familiar conceptions of the world — some of which are ancient and some of which are not — is not arbitrary. Less comprehensive conceptions are being replaced by more comprehensive conceptions. The more comprehensive our perspective on the world, the greater the number of anomalies we must face, and the greater the number of anomalies we face the more likely it is that our theories will be overturned, or at least partially falsified. But it is the wrong debate to ask whether theory change is rational or irrational. It is misleading, because what ought to concern us is how well our theories account for the ever-larger world that is revealed to us through our ever-more comprehensive methods of science, and not how well our theories conform to our presuppositions about rationality. The more we get the science right, reason will follow, shaping new intuitions and formulating new theories.

Our ability to discover (and to understand) ever greater scales of the universe is contingent upon our growing intellectual capabilities, which are cumulative. Just as in the STEM cycle science begets technologies that beget industries that create better scientific instruments, so too on a purely intellectual level the intellectual capabilities of one generation are the formative context of the intellectual capabilities of the next generation, which allows the later generation to exceed the earlier generation. Concepts are the tools of the mind, and we use our familiar concepts to create the next generation of concepts, which latter are both more refined and more powerful than the former, in the same way as we use each generation of tools to build the next generation of tools, which makes each generation of tools better than the last (except for computer software — but I expect that this degradation in the practicability of computer software is simply the software equivalent of planned obsolescence).

Our current generation of tools — both conceptual and technological — are daily revealing to us the inadequacy of our past conceptions of the world. Several recent discoveries have in particular called into question our understanding of the size of the world, especially in so far as the world is defined in terms of its origins in the Big Bang. For example, the discovery of hyperclusters suggest physical structures of the universe that are larger than the upper limit set to physical structures by contemporary cosmologies theories (cf. ‘Hyperclusters’ of the Universe — “Something is Behaving Very Strangely”).

In a similar vein, writing of the recent discovery of a “large quasar group” (LQG) as much as four billion light years across, the article The Largest Discovered Structure in the Universe Contradicts Big-Bang Theory Cosmology states:

“This LQG challenges the Cosmological Principle, the assumption that the universe, when viewed at a sufficiently large scale, looks the same no matter where you are observing it from. The modern theory of cosmology is based on the work of Albert Einstein, and depends on the assumption of the Cosmological Principle. The principle is assumed, but has never been demonstrated observationally ‘beyond reasonable doubt’.”

This formulation gets the order of theory and observation wrong. The cosmological principle is not a principle that can be proved or disproved by evidence; it is a theoretical idea that is used to give structure and meaning to observations, to organize observations into a theoretical whole. The cosmological principle belongs to theoretical cosmology; recent discoveries such as hyperclusters and large quasar groups belong to observational cosmology. While the two — i.e., theoretical and observational — cannot be separated in the practice of science, it is also true that they are not identical. Theoretical methods are distinct from observational methods, and vice versa.

Thus the cosmological principle may be helpful or unhelpful in organizing our knowledge of the cosmos, but it is not the kind of thing that can be falsified in the same way that, for example, a theory of planetary formation can be falsified. That is to say, the cosmological principle might be opposed to (falsified by) another principle that negates the cosmological principle, but this anti-cosmological principle will similarly belong to an order not falsifiable by empirical observations.

The discoveries of hyperclusters and LQGs are particularly problematic because they question some of the fundamental assumptions and conclusions of Big Bang cosmology, which is, essentially, the only large scale cosmological model in contemporary science. Big Bang cosmology is the explanation for the structure of the cosmos that was formulated in response to the discovery of the red shift, which implies that, on the largest observable scales, the universe is expanding. It is important to add the qualification, “on the largest observable scales” because stars within a given galaxy are circulating around the galaxy, and while a given star may be moving away from another given star, it is also likely to be moving toward yet some other star. And, even at larger scales, not all galaxies are receding from each other. It is fairly well known that galaxies collide and commingle; the Helmi stream of our own Milky Way is the result of a long past galactic collision, and at some far time in the future the Milky Way itself will merge with the larger Andromeda galaxy, and be absorbed by it.

Cosmology during the period of the big bang theory (a period in which we still find ourselves today) is in some respects like biology before Darwin. Almost all biology before Darwin was essentially theological, but no one had a better idea so biology had to wait to become a science capable of methodologically naturalistic formulations until after Darwin. The big bang theory was, on the contrary, proposed as a scientific theory (not merely bequeathed to us by pre-scientific tradition), and most scientists working within the big bang tradition have formulated the Big Bang in meticulously naturalistic terms. Nevertheless, once the steady state theory was overthrown, no one really had an alternative to the big bang theory, so all cosmology centered on the Big Bang for lack of imagination of alternatives — but also due to the limitations of the scientific instruments, which at the time of the triumph of the big bang theory were much more modest than they are today.

As disconcerting as it was to discover that the cosmos did not embody an eternal order, that it is expanding and had a history of violent episodes, and that it was much larger than an “island universe” comprising only the Milky Way, the observations that we need to explain today are no less disconcerting in their own way.

Here is how Leonard Susskind describes our contemporary observations of the expanding universe:

“In every direction that we look, galaxies are passing the point at which they are moving away from us faster than light can travel. Each of us is surrounded by a cosmic horizon — a sphere where things are receding with the speed of light — and no signal can reach us from beyond that horizon. When a star passes the point of no return, it is gone forever. Far out, at about fifteen billion light years, our cosmic horizon is swallowing galaxies, stars, and probably even life. It is as if we all live in our own private inside-out black hole.”

Leonard Susskind, The Black Hole War: My Battle with Stephen Hawking to make the World Safe for Quantum Mechanics, New York, Boston, and London: Little, Brown and Company, 2008, pp. 437-438

This observation has not yet been sufficiently appreciated. What lies beyond Susskind’s cosmic horizon is unobservable, as anything that disappears beyond the event horizon of a black hole has become unobservable, and that places such matters beyond the reach of science understood in a narrow sense of observation. But as I have noted above, in the practice of science we cannot disentangle the theoretical and the observational, but the two are not the same. While our observations come to an end at the cosmic horizon, our principles encounter no such boundary. Thus it is that we naturally extrapolate our science beyond the boundaries of observation, but if we get our scientific principles wrong, anything beyond the boundary of observation will be wrong and will be incapable or correction by observation.

Science in the narrow sense must, then, come to an end with observation. But this does not satisfy the mind. One response is to deny the mind its satisfaction and refuse to pass beyond observation. Another response is to fill the void with mythology and fiction. Yet another response is to take up the principles on their own merits and consider them in the light of reason. This response is the philosophical response, and we see that it is a rational response to the world that is continuous with science even when it passes beyond science.

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“Local” in a Cosmological Sense

Sunday

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The Conceptual Problem of Earth-Originating

Biota, Intelligence, Civilization, and Institutions

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There is a subtle conceptual problem involved in identifying earth-originating biota, intelligence, civilization, and institutions and their long-term, large-scale development. If industrial-technological civilization continues in its trajectory of development, we can expect our species and our civilization will spread throughout our solar system and eventually to other star systems. By now, this is an idea familiar to everyone. When earth-originating biota, intelligence, civilization, and institutions are found on other planets of our solar system, in built environments orbiting planets or the sun, or throughout other planetary systems of other stars, what will we call ourselves and our civilization?

That is just the beginning of the potential complexities. As earth-originating species and institutions spread across the galaxy, this cosmological expansion will constitute an adaptive radiation of an order of magnitude beyond any adaptive radiation that took place on Earth, when all earth-originating biota were confined to Earth. An adaptive radiation of such magnitude will likely mean changes of a proportional magnitude. This proportional magnitude will involve not only expansion in space but also expansion in time. Adaptive radiation may take advantage of the time-dilation properties of a relativistic universe, distributing organisms or institutions across both time and space. This latter form of adaptive radiation, when the institution concerned is civilization, I have called a temporally distributed civilization (cf. Spacetime Constraints and Possibilities). In the same spirit we might speak of temporally distributed species, intelligence, and institutions.

Earth-originating life and its corollaries (for intelligence, civilization, and institutions are corollaries of life), once established off the surface of the earth, i.e., once established extraterrestrially, becomes extraterrestrial life even though it is earth-originating. Moreover, given the spatiotemporal scale of the universe, earth-originating life that expands extraterrestrially will rapidly adapt itself to local conditions, undergoing adaptive radiation. As a consequence, this extraterrestrial earth-originating life (and its corollaries) will come to differ from the earth-originating biota that has remained on the earth, even as this life that has remained on the earth has itself continued to evolve and therefore differs both from extraterrestrial earth-originating life as well as the earth-originating life that was the common ancestor of both.

It is even possible that earth-originating life might expand in cosmological-scale adaptive radiation, some great catastrophe could subsequently befall life throughout our galaxy (such as a massive gamma ray burst from the supernova), sterilizing most of the living worlds, after which life would again expand into the galaxy from its remaining protected niches, perhaps even returning to a sterilized earth. Is this, then, terrestrial life, or extraterrestrial life? It is easy to see how we might dramatically multiply our terminology at this point. There will be Earth-originating biota (EOB), Earth-originating civilization (EOC), extraterrestrially-originating biota (ExOB), extraterrestrially-originating civilization (ExOC), and so forth. Is this helpful? Does it matter? Well, the particular label we use to describe life and its vicissitudes doesn’t matter, but what does matter is the natural history of life, and when life attains the capability of projecting itself over cosmological distances, the natural history of life will involve just such cosmological considerations as I have recounted here. Natural history will become cosmological history, and astrophysics will be as relevant to life and civilization as is geography to geocentric life and civilization.

I have worked on a variety of terms to try to accurately express the large scale structure of life in the cosmos, and most of my formulations to date have been unsatisfying. I have expressed the idea of the origin of life and civilization as eobiology (following Joshua Lederberg, the prefix “eo” means early, so “early biology” or the origins of life — cf. Eo-, Eso-, Exo-, Astro-) and eocivilization (by analogy with eobiology — also cf. The Terrestrial Eocivilization Thesis). I have expressed the idea of non-terrestrial civilizations as exocivilization (cf. The Law of Trichotomy for Exocivilizations). One way to express the idea of earth-originating biota, intelligence, civilization, and institutions would be with the term terragenic. While “terragenic” is not a particularly attractive word, it does communicate the meaning I would like to convey in an intuitively accessible fashion. Also, it immediately suggests its complementary term, which is a much more satisfying word: xenogenic.

Earth is the locus of all that we know of life, civilization, and technology in the cosmos. In other words, all known life is terragenic; all known civilization is terragenic; all known technology is terragenic. We could narrow the focus a bit more and note that all known civilization is anthropogenic and most known technology is anthropogenic (as I observed in The Genealogy of the Technium, there are instances of terragenic non-human technology in the form of non-human animal tool use), with the human beings responsible for these anthropogenic creations themselves being terragenic. All of this is true at this early point in the history of humanity and its civilization, but this will not always be the case. The adaptive radiation of life into the cosmos will mean that the terrestrial origins of life, intelligence, civilization, and institutions may become clouded in a distant and complex past in which life and its corollaries emerge, expand, adaptively radiate, are extirpated, and re-emerge and re-adapt from sources of life no longer terrestrial.

We are now in a position to make the necessarily distinctions between terragenic exocivilizations and xenogenic exocivilizations, or even terragenic astrocivilization and xenogenic astrocivilization. For example, a xenogenic terrestrial civilization would be the result of alien invasion and extirpation of human beings in order to build their own civilization on Earth. All of these terms might be useful and accurate, but until we have dramatic examples before our minds to fill in this schematically formulated concepts they will seem a bit empty and artificial. This is not real objection except for our intuition.

One way to express the earth-originating character of all known life and its corollaries and to project this on cosmological scales would be to adopt the word “local” as it is employed in cosmology. In astronomy and cosmology there is a use of the word “local” that is both revealing and instructive. “Local” is what includes us — like the local group of galaxies or the local cluster of galaxies — while that which is non-local does not include us. When astronomers mention the “local group,” the “local cluster,” or the “local supercluster,” they are talking about, respectively, the group of galaxies that include our Milky Way, the cluster of galaxies that includes our Milky Way galaxy, and the supercluster that includes our own Milky Way galaxy. By analogy and extension, we can easily understand “local life,” “local intelligence,” “local civilization,” and “local institutions.”

It is often said today that, “Galaxies are the building blocks of the Universe.” I’m certain that this has been repeated by many cosmologists; I don’t know who originated the line, but it can be found, for example, as the first sentence of Carlton Baugh’s review of The Road to Galaxy Formation by William C. Keel (Nature 421, 791-792, 20 February 2003). Our local galaxy may prove to be be source and origin of life, mind, intelligence, technology, civilization, and institutions for the cosmos at large, in which case the petty distinctions we will make as earth-originating life makes itself at home in our local galaxy will come to mean but little in the long term. In this case, the only sense of “local” that will really matter is that of our “local galaxy.” Thus the Milky Way become not merely a building block but the foundation stone of a universe of life and its corollaries.

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Arthur C. Clarke’s tertium non datur

Saturday

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Arthur C. Clarke is best remembered for this science fiction stories, but many of his dicta and aphorisms have become common currency and are quoted and repeated to the point that their connection to their source is sometimes lost. (Clarke’s thought ranged widely and, interestingly, Clarke identified himself as a logical positivist.) Recently I quoted one of Clarke’s well-known sayings in Happy Birthday Nicolaus Copernicus!, as follows:

“Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.”

quoted in Visions: How Science Will Revolutionize the Twenty-First Century (1999) by Michio Kaku, p. 295

In so saying, Clarke asserted a particular case of what is known as the logical law (or principle) of the excluded middle, which is also known as tertium non datur: the idea that, given a proposition and its negation, either one or the other of them must be true. This is also expressed in propositional logic as “P or not-P” (“P v ~P”). The principle of tertium non datur is not to be confused with the principle of non-contradiction, which can be formulated as “~(P & ~P).”

Even stating tertium non datur is controversial, because there are narrowly logical formulations as well as ontological formulations of potentially much greater breadth. This, of course, is what makes the principle fascinating and gives it its philosophical depth. Moreover, the principle of the excluded middle is subtly distinct from the principle of bivalence, though the two usually work in conjunction. Whereas the law of the excluded middle states that of a proposition and its negation, one of the other must be true, the principle of bivalence states that there are only two propositional truth values: true and false.

To get started, here is the principle of the excluded middle as formulated in The Cambridge Dictionary of Philosophy edited by Robert Audi:

principle of excluded middle, the principle that the disjunction of any (significant) statement with its negation is always true; e.g., ‘Either there is a tree over 500 feet tall or it is not the case that there is such a tree’. The principle is often confused with the principle of bivalence.

THE CAMBRIDGE DICTIONARY OF PHILOSOPHY second edition, General Editor Robert Audi, 1999, p. 738

And to continue the Oxbridge axis, here is the formulation from Simon Blackburn’s The Oxford Dictionary of Philosophy:

excluded middle, principle (or law) of The logical law asserting that either p or not-p. It excludes middle cases such as propositions being half correct or more or less right. The principle directly asserting that each proposition is either true or false is properly called the law of bivalence.

The Oxford Dictionary of Philosophy, Simon Blackburn, Oxford University Press, 1996, p. 129

For more partisan formulations, we turn to other sources. Mario Bunge formulated a narrowly syntactical conception of the law of the excluded middle in his Dictionary of Philosophy, which is intended to embody a scientistic approach to philosophy:

EXCLUDED MIDDLE A logical truth or tautology in ordinary (classical) logic: For every proposition p, p v ~p.

Dictionary of Philosophy, Mario Bunge, Prometheus Books, 1999, p. 89

By way of contrast, in D. Q. McInerny’s Being Logical: A Guide to Good Thinking we find a strikingly ontological formulation of the law of the excluded middle:

“Between being and nonbeing there is no middle state. Something either exists or it does not exist; there is no halfway point between the two.”

D. Q. McInerny, Being Logical: A Guide to Good Thinking, Part Two, The Basic Principles of Logic, 1. First Principles, p. 26

What these diverse formulations bring out for us is the difficulty of separating logical laws of how formal systems are to be constructed from ontological laws about how the world is constructed, and in so bringing out this difficulty, they show us the relation between the law of the excluded middle and the principle of bivalence, since the logical intuition that there are only two possible truth values of any one proposition — true or false — is so closely tied to our logical intuition that, of these two values, one or the other (but not both, which qualification is the principle of non-contradiction) must hold for any given (meaningful) proposition.

The powerful thing about Clarke’s observation is that it appeals to this admixture of logical intuitions and empirical intuitions, and in so doing seems to say something very compelling. Indeed, since I am myself a realist, and I think it can be shown that there is a fact of the matter that makes propositions true or false, I think that Clarke not only said something powerful, he also said something true: either there are extraterrestrial intelligences or there are not. It is humbling to contemplate either possibility: ourselves utterly alone in a vast universe with no other intelligent species or civilizations, or some other alien intelligence out there somewhere, unknown to us at present, but waiting to be discovered — or to discover us.

Although these logical intuitions are powerful, and have shaped human thought from its earliest times to the present day, the law of the excluded middle has not gone unquestioned, and indeed Clarke’s formulation gives us a wonderful opportunity to explore the consequences of the difference between constructive and non-constructive reasoning in terms of a concrete example.

To formulate the existence or non-existence of extraterrestrials in the form of a logical law like the law of the excluded middle makes the implicit realism of Clarke’s formulation obvious as soon as we think of it in these terms. In imagining the possibilities of our cosmic isolation or an unknown alien presence our terror rests on our intuitive, visceral feeling of realism, which is as immediate to us as the intuitions rooted in our own experiences as bodies.

The constructivist (at least, most species of constructivist, but not necessarily all) must deny the validity of the teritum non datur formulation of the presence of extraterrestrials, and in so doing the constructivist must pretend that our visceral feelings of realism are misleading or false, or must simply deny that these feelings exist. None of these are encouraging strategies, especially if one is committed to understanding the world by getting to the bottom of things rather than denying that they exist. Not only I am a realist, but I also believe strongly in the attempt to do justice to our intuitions, something that I have described in two related posts, Doing Justice to Our Intuitions and How to Formulate a Philosophical Argument on Gut Instinct.

In P or not-P (as well as in subsequent posts concerned with constructivism, What is the relationship between constructive and non-constructive mathematics? Intuitively Clear Slippery Concepts, and Kantian Non-constructivism) I surveyed constructivist and non-constructivist views of tertium non datur and suggested that constructivists and non-constructivists need each other, as each represents a distinct point of view on formal thought. Formal thought is enriched by these diverse perspectives.

But whereas non-constructive thought, which is largely comprised of classical realism, can accept both the constructivist and non-constructivist point of view, the many varieties of constructivism usually explicitly deny the validity of non-constructive methods and seek to systematically limit themselves to constructive methods and constructive principles. Most famously, L. E. J. Brouwer (whom I have previously discussed in Saying, Showing, Constructing and One Hundred Years of Intuitionism and Formalism) formulated the philosophy of mathematics we now know as intuitionism, which is predicated upon the explicit denial of the law of the excluded middle. Brouwer, and those following him such as Heyting, sought to formulate mathematical and logic reasoning without the use of tertium non datur.

Brouwer and the intuitionists (at least as I interpret them) were primarily concerned to combat the growing influence of Cantor and his set theory in mathematics, which seemed to them to license forms of mathematical reasoning that had gone off the rails. Cantor had gone too far, and the intuitionists wanted to reign him in. They were concerned about making judgments about infinite totalities (in this case, sets with an infinite number of members), which the law of the excluded middle, when applied to the infinite, allows one to do. This seems to give us the power to make deductions about matters we cannot either conceive or even (as it is sometimes said) survey. “Surveyability” became a buzz word in the philosophy of mathematics after Wittgenstein began using it in his posthumously published Remarks on the Foundations of Mathematics. Although Wittgenstein was not himself an intuitionist sensu stricto, his work set the tone for constructivist philosophy of mathematics.

Given the intuitionist rejection of the law of the excluded middle, it is not correct to say that there either is intelligent alien life in the universe or there is not intelligent alien life in the universe; to meaningfully make this statement, one would need to actually observe (inspect, survey) all possible locations where such alien intelligence might reside, and only after seeing it for oneself can one legitimately claim that there is or is not alien intelligence in the universe. For am example closer to home, it has been said that an intuitionist will deny the truth of the statement “either it is raining or it is not raining” without looking out the window to check and see. This can strike one as merely perverse, but we must take the position seriously, as I will try to show with the next example.

The day before the Battle of Salamis, Aristotle might have said that there would be a sea battle tomorrow or there would not be a sea battle tomorrow, and in this case the first would have been true; on other days, the second would have been true.

Already in classical antiquity, Aristotle brought out a striking feature of the law of the excluded middle, in a puzzle sometimes known as the “sea battle tomorrow.” The idea is simple: either there will be a sea battle tomorrow, or there will not be a sea battle tomorrow. We may not know anything about this battle, and as of today we do not even know if it will take place, but we can nevertheless confidently assert that either it will take place or it will not take place. This is the law of the excluded middle as applied to future contingents.

One way to think of this odd consequence of the law of the excluded middle is that when it is projected beyond the immediate circumstances of our ability to ascertain its truth by observation it becomes problematic. This is why the intuitionists reject it. Aristotle extrapolated the law of the excluded middle to the future, but we could just as well extrapolate it into the past. Historians do this all the time (either Alexander cut the Gordian Knot or Alexander did not cut the Gordian Knot), but because of our strong intuitive sense of historical realism this does not feel as odd as asserting that something that hasn’t happened yet either will happen or will not happen.

In terms of Clarke’s dichotomy, we could reformulate Aristotle’s puzzle about the sea battle tomorrow in terms of the discovery of alien intelligence tomorrow: either we will receive an alien radio broadcast tomorrow, or we will not receive an alien broadcast tomorrow. There is no third possibility. One way or another, the realist says, one of these propositions is true, and one of them is false. We do not know, today, which one of them is true and which one of them is false, but that does not mean that they do no possess definite truth values. The intuitionist says that the assertion today that we will or will not receive an alien radio broadcast is meaningless until tomorrow comes and we turn on our radio receivers to listen.

The intuitionists thus have an answer to this puzzling paradox that remains a problem for the realist. This is definitely a philosophical virtue for intuitionism, but, like all virtues, it comes at a price. It is not a price I am willing to pay. This path can also lead us to determinism — assuming that all future contingents have a definite truth value implies that they are set in stone — but I am also not a determinist (as I discussed in The Denial of Freedom as a Philosophical Problem), and so this intersection of my realism with my libertarian free willist orientation leaves me with a problem that I am not yet prepared to resolve. But that’s what makes life interesting.

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Happy Birthday Nicolaus Copernicus!

Tuesday

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Today we celebrate the 540^th anniversary of the birth of Nicolaus Copernicus. The great astronomer was born 19 February 1473 in Toruń, now part of Poland. The name of Copernicus belongs with the short list of thinkers who not only changed the direction of civilization, but also the nature and character of Western civilization. Copernicus as the distinction of having a cosmology named in his honor.

We would do well to recall how radically our understanding of the world has changed in relatively recent years. Up until the advent of modern science, several ancient traditions of Western civilization had come together in a comfortingly stable picture of the world in which all of Western society was deeply invested. The Aristotelian systematization of Christian theology carried out by Thomas Aquinas was especially influential. Questioning this framework was not welcome. But science was an idea whose time had come, and, as we all know, nothing can stop the progress of an idea whose time had come.

Copernicus began questioning this cosmology by putting the sun in the center of the universe; Galileo pointed his telescope into the heavens and showed that the sun has spots, the moon has mountains, and that Jupiter had moons of its own, the center of its own miniature planetary system. Others took up the mantle and went even farther: Tycho Brahe, Johannes Kepler, and eventually Newton and then Einstein.

Copernicus was a polymath, but essentially a theoretician. One must wonder if Copernicus ever read William of Ockham, since it was Ockham along with Copernicus who initiated the unraveling of the scholastic synthesis, out of which the modern world would rise like a Phoenix from the ashes of the medieval world. Ockham provided the theoretical justification for the sweeping simplification of cosmology that Copernicus effected; it is not outside the realm of possibility that the later theoretician read the work of the earlier.

Today, when our knowledge of cosmology is expanding at breathtaking speed, Copernicus is more relevant than ever. We find ourselves forced to consider and to reconsider the central Copernican idea from every possible angle. The Fermi Paradox and the Great Filter force us to seek new insights into Copernicanism. I quite literally think about Copernicanism every day, making Copernicus a living influence on my thought.

As our civilization grows in sophistication, the question “Are we alone?” becomes more and more pressing. Arthur C. Clarke wrote, “Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.” This insight is profound in its simplicity. Thus we search for peer civilizations and peer life in the universe. That is to say, we look for other civilizations like ours, and for life that resembles us.

SETI must be considered a process of elimination, which I take to already have eliminated “near by” exocivilizations, although we cannot rule out the possibility that we currency find ourselves within the “halo” of a vanished cosmological civilization.

A peer civilization only slightly advanced over our own (say 100-500 years more industrial development), if it is in fact a peer and not incomprehensibly alien, would also be asking themselves “Are we alone?” They, too, would be equally terrified at being alone in the cosmos or at having another peer civilization present. Because we know that we exist as an industrial-technological civilization, and we know the extent to which we can eliminate peer civilizations in the immediate neighborhood of our own star, we can assume that a more advanced peer civilization would have an even more extensive sphere of SETI elimination. They would home in on us as incredibly interesting, as an exception to the rule of the eerie silence, in the same way that we seek out others like ourselves. That is to say, they would have found us, not least because they would be actively seeking us. So this may be considered an alternative formulation of the Fermi paradox.

Despite the growing tally of planets discovered in the habitable zones of stars, including nearby examples at Tau Ceti which lies within our SETI exclusion zone (which excludes only civilizations producing EM spectrum signals), there is no evidence that there are other peer civilizations, and advanced peer civilizations would already have found us — and they would be as excited by discovering us as we would be excited in discovering a peer civilization. There are none close, which we know from the SETI zone of exclusion; we must look further afield. Other peer civilizations would also likely have to look further afield. In looking further afield they would find us.

I don’t believe that any of this contradicts the Copernican principle in spirit. I think it is just a matter of random chance that our civilization happens to be the first industrial-technological civilization to emerge in the Milky Way, and possibly also the first in the local cluster of galaxies. We are, after all, an accidental world. However, it will take considerable refinement of this idea to show exactly how the uniqueness of human civilization (if it is in fact locally unique) is consistent with Copernicanism — and this keeps Copernicus in my thoughts.

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The Transplanetary Perspective

Saturday

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Though I’ve already written a longish post on the relationships among earth sciences, planetary sciences, and space sciences, and I feel that a definitive formulation of this relationship continues to elude me, so I continue to write about it and think about it, in the hope that this exercise in self-clarification will eventually culminate in a more-or-less satisfying account. Or maybe not. But I will continue to think about it nonetheless, and I take a keen interest in the steady stream of new findings in planetary sciences, such as in Newborn Star Study Reveals Never-Before-Seen Stage Of Planet Birth and The Primordial Star at the Edge of the Milky Way that Shouldn’t Exist Challenges Theories of Star Formation.

Part of the difficulty is that the earth sciences, planetary sciences, and space sciences, while all having roots that go back to the very beginnings of human scientific inquiry, are relatively recent in their current incarnations, and any distinctions among them are similarly recent. Also, all sciences begin on the earth (what I will below call “earth-originating”), and all natural sciences begin, in a sense, as earth sciences, because human civilization and the science it produces originates on the earth, so that there is an inherent ambiguity once these earth-originating sciences are extrapolated beyond the earth to other celestial bodies (moons, planetesimals, etc.), other planets in our solar systems, other solar systems around other stars, other star systems in other galaxies, and so on.

What does Michel Foucault have to do with planetary science?

There is a quote from Foucault that I have cited on several occasions that is (partially) relevant here:

Each of my works is a part of my own biography. For one or another reason I had the occasion to feel and live those things. To take a simple example, I used to work in a psychiatric hospital in the 1950s. After having studied philosophy, I wanted to see what madness was: I had been mad enough to study reason; I was reasonable enough to study madness. I was free to move from the patients to the attendants, for I had no precise role. It was the time of the blooming of neurosurgery, the beginning of psychopharmacology, the reign of the traditional institution. At first I accepted things as necessary, but then after three months (I am slow-minded!), I asked, “What is the necessity of these things?” After three years I left the job and went to Sweden in great personal discomfort and started to write a history of these practices. Madness and Civilization was intended to be a first volume. I like to write first volumes, and I hate to write second ones. It was perceived as a psychiatricide, but it was a description from history. You know the difference between a real science and a pseudoscience? A real science recognizes and accepts its own history without feeling attacked. When you tell a psychiatrist his mental institution came from the lazar house, he becomes infuriated.

Truth, Power, Self: An Interview with Michel Foucault — October 25th, 1982, Martin, L. H. et al (1988) Technologies of the Self: A Seminar with Michel Foucault, London: Tavistock. pp.9-15

The portion of the above most often quoted out of context is this:

You know the difference between a real science and a pseudoscience? A real science recognizes and accepts its own history without feeling attacked.

Far from the earth sciences, planetary sciences, and space sciences (or, rather, their predecessors) constituting pseudo-sciences, they are the very standard by which we ought to judge “hard” natural sciences, but as earth-originating sciences are extrapolated beyond the earth there may be an intellectual tension (hopefully, a creative tension) between the earth-specific forms of earth-originating sciences, and the generalized forms that these sciences take when earth-originating sciences are applied to other planets. I don’t think that planetary sciences and space sciences will feel “attacked” by their earth-originating predecessors, but the tendency to specialization in the most advanced natural sciences may well lead to territoriality among disciplines. This would be regrettable.

The generalization of earth-originating sciences into non-earth-specific planetary sciences and space science will be a necessary prerequisite to the long term growth of human civilization. A future interstellar civilization will be intensely interested in where in the galaxy valuable resources are to be found, in the same way that our planetary-based (and, currently, planetary-bound) civilization is intensely interested in the distribution of mineral resources under the surface of the earth. Much of the contemporary relationship between science and industry stems from this need for resources to fuel the fires of industry. (In this connection I urge the reader to consult the excellent book by Simon Winchester, The Map That Changed the World: William Smith and the Birth of Modern Geology, which traces the development of the first geophysical map of England to the search for coal seams.)

What coal and oil have been to planetary civilization, titanium and fissionables (inter alia) will be to interplanetary and interstellar civilization; and the role that coal and petroleum geology have played in the exploitation of coal and oil for planetary civilization will have their parallel in the role that planetary sciences and space sciences will have in the exploitation of resources necessary to interplanetary and interstellar civilization. To grow as a civilization, therefore, we need to adopt a transplanetary perspective in our sciences. This is already occurring.

Planetary formation must ultimately be understood in the context of stellar formation, since stars and planets ultimately coalesce from the same disc of gas and dust, and stellar formation must ultimately be understood in the context of galactic formation, since stars coalesce from the matter that swirls together as galaxies, and galactic formation must ultimately be understood in the context of the formation of galactic clouds, clusters, and superclusters, etc. In short, the entire structure of the universe is implicated in the formation of planets, and how we are to distinguish kinds of planets or generations of planets.

Astronomers distinguish between population I stars, population II stars, and population III stars (from youngest to oldest, respectively), based on their generation of enrichment with heavier elements (called the metallicity, or Z, of a star, i.e., its composition in terms of chemical elements other than hydrogen and helium) as a result of the nucleosynthesis of earlier generations of stars. To date, population III stars, hypothetically extremely metal-poor stars from the earliest ages of the universe (coincident with the advent of the stelliferous age and the universe “lighting up” with star light), have been postulated but not observed. However, some recently reported observations (The First Stars of the Universe — Major Discovery Announced by MIT) may be of a population III star.

It is to be expected that each of these populations of stars will have planetary systems typical of for these particular stellar populations (if they have planetary systems at all). If, then, we can refine the astrophysics and cosmology of stellar and planetary formation, breaking down population I stars into a more finely-grained account, perhaps even tracing back individual stars to individual stellar nurseries, it may be possible to determine the likely composition of solar systems (and therefore their resources available for commercial and industrial exploitation) derived from a given stellar nursery. Stars and their planetary systems, where these planetary systems exist, formed from one and the same concentration of gas and dust, so that there is a systematic correlation between the chemical composition of stars and their planetary systems, both in the case of our own solar system and in other solar and planetary systems that science has only recently begun to study. While stars and planets may form at different times and from different portions of a proto-planetary disc, the whole process of stellar and planetary formation constitutes a single natural history of a solar system.

As I noted above, this kind of research is already underway. Robert McGown has directed by attention to the paper Enhanced lithium depletion in Sun-like stars with orbiting planets published in Nature, which the authors conclude with this paragraph:

“It is known that solar-type stars with high metallicity have a high probability of hosting planets. Those solar analogues with low Li content (which is extremely easy to detect with simple spectroscopy) have an even higher probability of hosting exoplanets. Understanding the long-lasting mystery of the low Li abundance in the Sun appears to require proper modelling of the impact of planetary systems on the early evolution of solar analogue stars.”

“Enhanced lithium depletion in Sun-like stars with orbiting planets,” Garik Israelian, Elisa Delgado Mena1, Nuno Santos, Sergio Sousa, Michel Mayor, Stephane Udry, Carolina Domínguez Cerdeña1, Rafael Rebolo1, & Sofia Randich, Nature 462, 189-191 (12 November 2009)

The lithium-planetary system correlation suggests a range of research questions, such as the following: Is the sun especially rich or poor in any other element that might point to the existence or composition of a proto-planetary disc during stellar or planetary formation? Does the chemical composition of the planets of our solar system stand in any systemic or predictive relationship to the chemical composition of our sun as revealed by its spectrum? Does the spectrum of a star predict not only the presence or absence of a planetary system, but also the chemical composition of any planets? Does the chemical composition of planets predict the chemical composition of the stars they orbit?

The lithium-planetary system correlation also suggests research questions bearing upon stars that have no planetary system associated with them. While the technology does not yet exist to study in detail stars without planetary systems, improved telescopy and imaging techniques may provide data for such questions in the not distant future. The most obvious hypotheses to account for stars without associated planetary systems would include isolated stars formed from a proto-stellar mass with nothing left over for planets to form, and solar systems with asteroid belts as large as an entire solar system, such the the matter for planetary formation was available but no planets formed despite the existence of a proto-planetary disc. It is an especially interesting question whether lithium had any role to play in the planetary formation or the lack thereof in either of these cases.

However, lithium-planetary system correlation relies on our very sketchy knowledge of exoplanet systems at present. All of this knowledge is strongly skewed toward large planets that tug their stars around. Astronomers have been able to figure out the planetary system around Alpha Centauri because it is close enough to detect the smaller wiggles that would betray smaller planets, but even here we don’t have any information about what surrounds the star other than a few planets. Stars without any large planets at all might have many smaller planets, or they might have a solar system sized asteroid belt. There are probably also a few stars in which all the precursor materials managed to get into the star with very little left over for planets or asteroids.

Perhaps it could be said that lithium deficiency correlates with the absence of large planets, because we have no idea what may be surrounding stars with no detectable large planets — not until we have a very large telescope in orbit or on the moon. This too suggests interesting questions. How might the formation of large planets be correlated with lithium deficiency in a star? Also, it has been theorized that large planets clear debris out of a solar system, thereby making it possible for smallish, rocky planets to exist in a more stable planetary environment, and a more stable planetary environment likely correlates with the emergence of life and eventually industrial-technological civilization. Thus lithium-planetary system correlation could extend all the way to being a predictor of industrial-technological civilizations.

It might be fruitful to compare the lithium spectra from double (and triple) star systems with known systems including hot Jupiter exoplanets (some of which are just short of being companion stars) and stars that show no evidence of large planet formation. Also, it is worth considering whether double stars or hot Jupiters play a role in the formation of other planets, e.g., such a large gravitational mass might upset the proto planetary disc just enough that the disc congeals into (large) planets, whereas the absence of such a gravitational “trigger” might result in greater uniformity in the proto-planetary disc and therefore its failure to congeal into discrete planets.

Such inquiries are now only in their infancy, and we can both expect and look forward to a flowering of knowledge in the fields of planetary science and space science as the technology to image distant stars and planetary systems rapidly improves, and as access to earth orbit becomes routine, allowing for a robust multiplicity of telescopes in earth orbit outside the atmosphere.

Not only will science on the whole be stimulated by this research, but, as I have often argued, it is the intrinsic nature of industrial-technological civilization to be spurred on by scientific innovations that result in new technologies, and new technologies are engineered into new industries that go on to create new scientific instruments that increase and improve scientific knowledge. Thus the cycle that defines and drives industrial-technological civilization escalates. This cycle is nowhere even close to being exhausted; as I have just pointed out above, instead of a handful of telescopes in orbit, the next decades may see hundreds if not thousands of telescopes in orbit, as there are now thousands of telescopes on the surface of the earth.

Civilization itself will be the beneficiary of these developments, as it continues its spiral of technological progress with its unexpected and unpredicted advantages for human life and commercial opportunity. There is also the sheer joy of better understanding the world in which we live. All of these factors will continue to fuel the growth and diversification of civilization in the future, thus at least partially mitigating against the existential risk of permanent stagnation.

The transplanetary perspective resulting from the extrapolation and generalization of earth sciences into planetary science and space sciences is to be welcomed for these far-reaching benefits both practical and intellectual.

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