Three Big Bangs Read online

  (5) The parameters of physics contain a small constant called the fine structure constant, usually designated α, which controls the strength of the electromagnetic force. The constant, which is a dimensionless quality, is 7.297352570 x 10-3, or

  It was first discovered during analysis of the fine structure of atomic energy spectra, but has proved to be important because it sets the relation of the electromagnetic force to the strong nuclear force, about a hundred times weaker. The strong nuclear force holds a multiproton nucleus together, despite the electromagnetic force (proton repelling proton) that would blow it apart. Cosmologists debate whether the fine structure constant might be quite slowly changing, but if it had long been much different, that would have changed the number of elements that can exist in nature, shifting these force relationships. If it were much stronger, many fewer elements could exist, including many necessary for life—if 4 percent stronger, carbon would no longer be produced in stellar fusion. If stronger, this would also change chemical bonding, which occurs on the basis of properties of the electrons in outer shells. Thus the bonding and folding protein chemistry on which life depends would not be possible (Barr 2003:125–126; Barrow 2004:411–419).

  (6) Physicists speak of symmetry-breaking (Brading and Castellani 2003). The term is widely used in various sciences when a lawlike system moves from a prior state with as yet some undifferentiated order into a differentiating juncture, where the developing system splits, transforms, takes one direction and forgoes others. The process crosses a critical point where spontaneous passage events, perhaps small fluctuations, determine which branch is taken, subsequently operating under laws differentiated in the now broken symmetry. With objects, a hydrogen atom is symmetrical; so is an oxygen atom; but when joined as H2O the molecule is polar, with positive and negative ends, and thus asymmetrical.

  Homogeneous structures may have great symmetry (oxygen atoms, salt crystals), but complex structures, if preserving some symmetries, also require much asymmetry (a DNA molecule, a spiral helix with a unique linear triplet sequence). There is, paradoxically, less order of the symmetrical kind to achieve more order of the complicated kind—which may also involve some messiness. Breaking symmetry may be the first step to getting something happening. There is phase change with novelty—with “broken symmetry,” as F. W. Anderson put it in a famous paper, “More is Different” (Anderson 1972).

  Cosmologists suppose symmetry-breaking at the startup of the universe. In big bang cosmology, despite worries that we earlier noticed about whether scientists have rational access to the first moments, some suppose (speculate) that during high temperature Planck time (the first 10-43 seconds) the four forces were unified into a single superforce. Afterward, with lowering temperatures, there were the earliest symmetry breaks that separated the original force, resulting in the four forces we know in the present universe (fig. 1.1, Nave 2002). Cosmologists may pay particular attention to the breaking of the once-combined electromagnetic-weak (electroweak) force into the electromagnetic and weak forces. The single superforce explodes into “more,” and that is “different.” Something starts to happen.

  These different forces, as already noted, are responsible for features of stars and planets, the diversity of the elements, and the bonding chemistries without which biomolecules and life would not be possible (making water possible, for instance). John Barrow remarks: “The situation in which the outcomes of a law break its symmetry is termed ‘symmetry-breaking.’ It has been known but not fully appreciated for years. And it is responsible for the vast diversity and complexity of the real world” (Barrow 2007:138). David Gross, in a review of symmetry in physics, concludes: “The secret of nature is symmetry, but much of the texture of the world is due to mechanisms of symmetry breaking” (Gross 1996:14257). Accounts of symmetry-breaking during the primordial big bang are speculative and likely to change. But somehow or other these four forces did come into being in their present biocentric/anthropic form. If they had not, the universe we know, life in it, and we ourselves would not be here. That is not speculative.

  Figure 1.1 Symmetry-breaking at the big bang explosion (Nave 2002)

  Cosmic Results: Predictable and Surprising

  Are these ongoing results of the primordial big bang predictable or surprising? Or both? Is the outcome prespecified? Blueprinted into the universe—this universe at least, as a theory of everything might suggest? Or is the outcome in significant part contingent, and surprising, as Davies’ “cosmic jackpot” suggests?

  “Prediction” and “surprise” have been analyzed in philosophies of science. Science prefers lawlike regularities, which, when applied to a set of initial conditions, enable prediction. There are no surprises. But science often finds surprises, indeed dramatic singularities, in natural history. Typically, this forces the question whether with a better law, applied to those initial conditions, the outcome is no longer surprising but rather to be expected. At the cosmic level, scientists have no such theory of everything. When philosophers or theologians wonder what to make of this, they may say that some deeper explanations are needed, such as God or Platonic forms, whereupon the jackpot universe becomes less surprising.

  However, if there is discovered a theory that makes the three big bangs predictable, they may again say that we need a deeper account of why there should be a universe with such built-in inevitability. Either way, in a surprising universe or an inevitable universe, we need an account of matter-energy generating life, of life generating mind.

  It is difficult to envision any cosmology that does not require creation of the complex out of the simple, more out of less, something somehow out of nothing. It is difficult to imagine that all of the remarkable phenomena that have worked together to make our universe possible will disappear. It is difficult to imagine a universe more staggering, dramatic, and mysterious, for all its rationality. It is difficult to imagine a universe that starts simpler (perhaps as quantum fluctuation in a vacuum) and becomes more complex (Homo sapiens sequencing its own genome, with moral debates whether and how we ought to revise ourselves). The universe story, the Earth story is a phenomenal tale of more and more later on out of less and less earlier on. As events move from quarks to protons, from amino acids to protozoans, to trilobites, to dinosaurs, to persons, from spinning electrons to sentient animals, from suffering beasts to sinful persons, the tale gets taller and taller. No doubt there will be surprises in cosmology in the next century; surprises in discovering biodiversity, terrestrial, even extraterrestrial; and surprises in human achievements and powers, a taller tale still. Is the end of the story somehow already there in the beginning?

  Generating these heavy elements, which on Earth become the seeds of life, does seem deterministic in origin. In that sense the periodic table of chemical elements is latent in the big bang—including those remarkable biogenic elements. So are the thirty-two crystal classes. Molecular structures, molecules and lattices, as found in water, pyrite, salt, and silica, inevitably develop somewhere. The system is prone to modular constructions, which may get intertwined or compounded (hyper-cycles), and the stable and metastable ones survive. Random elements combine with overall order (as with fractals). Beyond aggregation, matter is regularly spontaneously organizing, as when molecules and crystals form. In some situations, especially with a high flow of energy over matter, patterns may be produced at larger scales (Prigogine and Stengers 1984). These patterns may further involve critical thresholds, often called self-organized criticality (Bak 1997). Such processes are “automatic,” sometimes called “self-organizing,” although initially the “auto” should not be taken to posit a “self,” but rather an innate principle of the spontaneous origination of order.

  Planets may form with differences, especially if there are chaotic factors in their origins. “According to modern views, the number of planets and the size of planetary orbits was determined more or less accidentally during the complicated process whereby our solar system condensed out of a gigantic inters
tellar cloud” (Wilcsek 1999:303). But where planets do form, given suitable conditions on some of them, igneous, sedimentary, and metamorphic rocks are inevitable. Where there are fluids, there will appear loops and cycles, bubbles, currents, eddies, tornadoes. There seem to be chaotic thresholds that trigger amplified particulars (such as the Grand Canyon), but there are canyons generically—on the moon, Mars, and elsewhere in space.

  There are other planets. The presence of several hundred possible planets has been detected, and these do seem to be diverse, though none suitable for life is yet known. Rather, it seems that planetary systems configured like our solar system are quite rare. If there proves to be a second (or prior) genesis of life elsewhere, that will be welcome. But Earth will not on that account cease to be remarkable (a remarkable accident?), nor will its particular natural history—trilobites, dinosaurs, primates—and social history—Israel, Europe, China, global capitalism, the Internet—cease to be unique in the universe.

  We could make better estimates of the random and the probable if ever we did discover a second genesis (astrobiology, exobiology). We might yet discover life in our solar system, though discovering intelligent life seems quite unlikely. We might detect life on relatively near stars, but about life in other galaxies we are likely to remain long in ignorance; the distances are too great. The only second genesis we are likely ever to be able to detect in the vast reaches of space is the unlikeliest of all that we will find: intelligent life smart enough to transmit electronic signals across space. Peter D. Ward and Donald Brownlee make such conclusions, indicated in their title: Rare Earth: Why Complex Life Is Uncommon in the Universe (2000). Again, given the distances in space and time, we are unlikely ever to be able to communicate with such life. We may be the result of cosmic natural history generally, of earthen natural history peculiarly, the most complex event in the universe, and stuck in our solitude.

  A good planet is hard to find, and Earth is something of an anomaly, so far as we yet know. Earth has a rather good star, the sun, which is stable, solitary, and situated about 28,000 light-years from the center of our galaxy, a relatively quiet part of the galaxy, about halfway between the quite active middle and the active outer parts. Deadly radiation from supernovae explosions or bursts of intense X-ray and ultraviolet radiation are unlikely. The solar neighborhood does have a relatively high abundance of the heavier elements produced from supernovae, all those heavier than hydrogen and helium—an abundance the astronomers call “metallicity.”

  Most planets, even though they contain suitable elements, will not be in a habitable temperature zone. Located at a felicitous distance from the sun, Earth has huge amounts of liquid water: seven oceans covering about three quarters of its surface. “Aqua” would have been a better name than “Earth.” Water is an anomalous liquid, with a maximum density near 4 degrees Celsius, so that ice floats, with high latent heat and slow evaporation, with solvent properties suitable for life. The polar structure of water and its anomalous properties later fit impressively into the fundamental support of critical biological structures in carbon-based life (Finney 2004). These include lipid bilayers, which organize the compartments within cells, or the funneling and maintaining protein folding (Chaplin 2001; Levy and Onuchic 2006). Such properties depend on the strengths of those bonding forces noted earlier; they are inevitable, but become available for life only on a lucky planet such as Earth/Aqua.

  On Earth there is atmosphere, a suitable mix of elements, compounds, minerals, and an ample supply of energy. Radioactivity deep within the Earth produces enough heat to keep the tectonic plates of its crust constantly mobile in counteraction with erosional forces, and the interplay of such forces generates and regenerates landscapes and seas—mountains, canyons, rivers, plains, islands, volcanoes, estuaries, continental shelves. Earth’s moon produces tides, significant in the evolution of life. “It appears that Earth got it just right,” conclude Ward and Brownlee (2000:265). All this results in an anomalous, fortuitously good location—though it is hard to say whether the jackpot Earth is lucky, likely, or inevitable. William C. Burger does call Earth a “perfect planet.” “I believe we can all agree that we live on a glorious planet, and that our intellectual achievements have been quite amazing” (Burger 2003:3). On Earth, complexity does increase again, by many more orders of magnitude.

  Events resulting from the big bang might be contingent at several points:

  (1) The setup at the time of the big bang might have been otherwise; it was what it was owing to startup contingencies. We examined this issue earlier, wondering if there might be a “theory of everything” that would determine these events, making it inevitable, if a big bang happened, that it happen the way it did, with the fine-tuned results. No such theory exists at present. Even if it did, one would still have to wonder whether such a determinate process had to be launched, and also to puzzle about how the requirements of physical theory happened to be also those required for life on Earth.

  (2) By another account our universe can be contingent within some ensemble of universes, one of multiple universes, and a lucky one. Currently the most fashionable way to account for the surprising aspects of our universe, our big bang, is to suppose that there was not just one big bang but very many. Or perhaps our one big bang produced a megaverse with regional, disjoint universes, bubble universes, each different—a bigger big bang than we had thought and bigger than we can observe from our location. There is no one universe but multiverses, multiple universes. Astronomy has steadily been increasing the size of this universe, and now we need to suppose more vastness again.. This universe is only one of a run of universes (Carr 2007; Rees 2001). There are other, parallel space-times with different laws, constants, contents, histories. Most are uninteresting, but some lucky ones are interesting. Most are not cognizable worlds because their laws and constants are such that those kind of worlds cannot produce cognizers who inhabit them. Maybe even all the universes that can exist do exist (Tegmark 2003). If so, it is not so surprising that some of them are suitable for the formation of heavy elements and the evolution of life.

  Another possibility is: big bang, big squeeze, big bang, big squeeze, a recycling universe, sequential universes, and our particular current cycle at random has the right characteristics for life (Wheeler 1975). This, however, looks unlikely with recent evidence that our universe will continue expanding forever. By another account, black holes are generating other universes (Smolin 1997). If there are multiple universes, what is unlikely on one throw of the dice becomes likely if you roll the dice often enough.

  But these are complex explanations indeed—to invent myriads of other worlds existing sequentially or simultaneously with ours, in order to explain how this one can be a random one from an ensemble of universes, and so a little less surprising in its anthropic features. There is of course little or no scientific evidence that other universes exist. They are mostly scientific conjectures, if indeed these are scientific hypotheses of the familiar kind at all, since the existence of other, nonobservable universes with differing constants and laws is not directly testable, only marginally so by extrapolation from what we may know about this one. Their existence might make some phenomenon in our universe more plausible. But we in our universe are too separated from them to have a science about them.

  Their proponents seem inclined to believe they exist not so much on the basis of any actual evidence that these other universe-regions exist, but rather because, if true, that would make this universe less surprising. Cosmologists of course are licensed to speculate (Tegmark 2003). True, this universe we do inhabit has often proved immensely bigger than we supposed, but we have strong scientific evidence for other galaxies, for deep space, deep time. Martin Gardner puts the contrast bluntly: “The stark truth is that there is not the slightest shred of reliable evidence that there is any universe other than the one we are in. No multiverse theory has so far provided a prediction than can be tested” (Gardner 2003:9). So in the meanwhile, it seems a mor
e economical explanation (remembering that science often urges simplicity in explanation) to posit only the one universe we know and some constraints on it that make it right for life.

  (3) Given some startup big bang, contingent or inevitable, there might also be contingency en route in the unfolding natural history. The basic laws and constants might (after the startup) be determinate, but there might be contingency nevertheless within the framework of such basic laws and constants. The laws include quantum physics, for example, which has indeterminacy within it, by most accounts an ontological indeterminacy. If quantum events can ever be amplified to larger scales, those results would be to some degree contingent.

  In fact, we have not far to seek for evidence that molecular and even atomic phenomena are often amplified. In biochemistry and genetics, events at the phenotypic level are profoundly affected by events launched at the genotypic level. Such events may sometimes be affected by quantum events, as when random radiation affects point mutations or genetic crossing over. This may affect enzyme functions or regulatory molecules, as when allosteric enzymes, which amplify processes a million times, are in turn regulated by modifier molecules, of which there may be only a few copies in a cell, made from a short stretch of DNA, where a few atomic changes can have a dramatic real-life effect. A single base pair altered can shift a whole reading frame.