Weird Life: The Search for Life That Is Very, Very Different from Our Own

by David Toomey

  So we have, in science fiction, a range of weird life. At one extreme the centipedes—superficially weird but fundamentally familiar; at the other the living ocean—profoundly weird and utterly unknowable.

  Is there, as it were, a weird medium? In fact, a large body of work depicts life that human characters cannot hope to understand intellectually, but can appreciate aesthetically. These organisms appear in the fiction of Joseph Henri Boex, a Belgian expatriate who in the 1880s settled in Paris and adopted a pen name that, Englished, is “Rosny the Elder.” (He and a younger brother who had coauthored many works parted professional ways and split the name they had been using—J. H. Rosny—according to birth order.) The name may sound as though it belongs to a medieval biographer of saints’ lives, but as we’ll see, Rosny’s concerns strayed far from the doctrine of most churches. Only a few of Rosny’s works were ever translated from the original French, and most of those are out of print, probably because critics have been less than charmed by what one called his “prolixity, maudlin sentimentality, and awkward stylistic mannerisms.”9 Such qualities seem not to have troubled Rosny’s readers: in his own lifetime he enjoyed a popular following that in size rivaled those of Jules Verne and H. G. Wells.

  Rosny’s plots were kaleidoscopic mash-ups of, well, everything. One features a Stone Age tribe discovered living in the Arctic alongside woolly mammoths, “rescued” by an explorer and transplanted to northern Africa. Another concerns a society of intelligent vampire bats. Still another involves a young man who can see beings living invisibly alongside us, sometimes brushing against us, and (shades of a shadow biosphere) subtly impinging on our world as we impinge on theirs.

  Like Wells, Rosny took inspiration from Darwin’s theory of natural selection, and was especially intrigued by its claim that nature had produced and would continue to produce “endless forms most beautiful and most wonderful.”10 He imagined many: living minerals that threatened prehistoric tribes of humans; “ferromagnetic” entities that, far in Earth’s future, supplant organic life; and on Mars, luminous networks of intelligent phosphorescence. All are so alien that humans cannot understand them or communicate with them, but not for lack of trying. Rosny’s humans are adventuresome sorts. In one story, a male human scientist meets a female Martian who, like all her species, is possessed of “trilateral symmetry”—that is, six eyes, six ears—and before you can shrug “l’amour,” she and the scientist are deeply involved in matters not strictly scientific. Although the Martian maîtresse may not be not weird life in the sense I’ve been meaning, the open-mindedness that allows Rosny’s scientist to see the beauty in her trilateral symmetry also allows him to be properly awed by organisms that are quite beyond human understanding.

  We’ve discussed hypotheses of life that differs from the familiar in many ways—its chemical structures and pathways and the “handedness” of its DNA. We’ve discussed hypotheses of life that uses a liquid medium other than water, life that uses mediums that are not liquid, and life that uses no medium whatsoever. We’ve discussed hypotheses of life driven by a nuclear chemistry. And we’ve considered the places such organisms might call home: rock surfaces in the American Southwest, hydrothermal vents on the ocean floor, Martian permafrost, the water-ammonia oceans of Jupiter’s moons, the cold methane and ethane lakes on Titan, the deep hydrogen-rich atmospheres of giant planets, the exotic ices in comets, the crusts of neutron stars, and the vast reaches of space itself. We would seem to have amassed as complete an inventory of weird life and weird-life environs as is possible.

  Yet some scientists think there may be life weirder still. All the previous—from the microbes that might produce desert varnish, to the hydrogen-eating dirigibles, to the sentient interstellar nebulae—if they exist—would abide by the same natural laws that you and I abide by: the strength of gravity, the particular mass of the subatomic particles of which we are composed, and so forth. These laws are so fundamental that few of us have bothered to think of them, much less wonder what worlds might result if they were otherwise. Yet there may be places where such laws are otherwise, and a handful of scientists suspect that at least a few such places might harbor life—the weirdest life of all.

  * * *

  * The definition of weird life that has been operative in much of this book—“life that is not descended from LUCA”—requires some modification here. Much extraterrestrial life in science fiction, given its age, location, and/or nature, cannot possibly be descended from LUCA, yet (rather improbably) is depicted as being indistinguishable from life we know. Of course, most renderings of extraterrestrial life in science fiction do not address questions of that life’s ancestry to begin with. For the sake of convenience, in this chapter I’ll disregard the issue of lineage and define weird life simply as life that is fundamentally different from that we know.

  * The planetwide ecosystem based on silicon is featured in Alan Dean Foster’s Sentenced to Prism. The organism based on silicon and superfluid helium appears in Arthur C. Clarke’s “Crusade.” The Kuiper belt organisms are featured in Robert L. Forward’s Camelot 30K. The organisms that use liquid helium as a biosolvent are featured in Larry Niven’s Known Space universe. The “flame-like inhabitants” of stars appear in Olaf Stapledon’s Last and First Men and The Flames. Other stellar denizens make appearances in David Brin’s Sundiver and Frederick Pohl’s The World at the End of Time. The plasma-based life making its home in the accretion disk of a black hole is in Gregory Benford’s Eater. Photino-based organisms and organisms composed of quantum wave functions are featured in several of Stephen Baxter’s novels. Organisms that operate in a parallel universe appear in Isaac Asimov’s The Gods Themselves.

  * To depict weird life in general terms, an author doesn’t need to invent a different biology or biochemistry—welcome news to that author, as such efforts would require specialized knowledge. Probably we shouldn’t be surprised, though, that many of these stories are by authors with training in the sciences. Fred Hoyle, who imagined a sentient interstellar nebula, was a professional astronomer. Robert Forward, who described beings with a nuclear biochemistry, was a physicist. Stanley G. Weinbaum, whose 1934 short story “A Martian Odyssey” features a silicon-based creature that creaks when it moves and produces silicon dioxide (not carbon dioxide) as waste, had a degree in chemical engineering. Gregory Benford, who described life near black holes (among other exotic locales), is a practicing astrophysicist.

  CHAPTER NINE

  Weird Life in the Multiverse

  Possibilities unrealized and roads not taken exert a strong pull on our imaginations, and many of us surrender to that pull annually, to reread Dickens’s A Christmas Carol and watch Capra’s It’s a Wonderful Life one more time. We are drawn to both for their what-ifs and what-might-have-beens, but we leave them thinking about our own—another year’s worth every year. There is something both wondrous and a little terrifying in such thoughts, and it seems fitting that in the story and film they are premised on the supernatural, introduced by a ghost and an angel. But as guides to alternate realities, it turns out that ghosts and angels aren’t necessary. In fact, findings in science—especially in theoretical physics and cosmology—are the basis for many more recent fictional alternate realities. Such places are called, among other things, parallel universes.

  Parallel universes have provided grist for innumerable comic books and a whole subcategory of science fiction. In the last decade or so, when science fiction broke into the cultural mainstream, parallel universes came with them. Nowadays they seem to be everywhere. They supply plots for Hollywood and television techno-thrillers, for cerebral independent films, and for dense philosophical novels whose characters struggle with questions of fate and free will. One reason this is happening now, no doubt, is the news that all the what-ifs and what-might-have-beens may actually be out there somewhere.

  In recent years, cosmologists and theoretical physicists have devoted much attention to the concept of a multiverse—that is, a set of univ
erses whose number is at least very large and may be infinite. It’s an unsettling idea, in that it challenges not only our intuition but our vocabulary. Conventionally, the word “universe” has meant “everything” or “all there is.” And so we might reasonably ask how anything can be outside the universe or apart from it, or indeed how there can be more than one. By way of an answer, we’ll need to back up a bit.

  THE TRADITIONAL UNIVERSE

  In the sixteenth century the Italian philosopher Giordano Bruno asserted that nature’s perfection and God’s power necessitated an infinity of worlds.1 Several hundred years hence, and by a rather different chain of reasoning, scientists arrived at much the same conclusion. By the twentieth century, astronomers and cosmologists had amassed evidence suggesting that the universe—all of space and everything in it—extended outward to infinity in all directions. (The alternative seemed downright nonsensical: how, after all, could there be an end to space?) They had also amassed evidence suggesting that the laws of nature were the same throughout. The upshot—a universe that was infinite and more or less homogenous—became the traditional model of the universe, and like most traditional models, it had variants.

  One variant, introduced by Albert Einstein, resulted from the possibility that space might be curved. If three-dimensional space were curved as a two-dimensional surface can be curved on, say, a sphere, then the consequence would be a universe that was finite (there is only so much surface on a sphere) yet unbounded in that (as on the surface of that sphere) if you traveled far enough in a straight line, you would arrive back where you started—from the opposite direction. Of course, such a universe might be curved in other ways: like the surface of a saddle whose edges extend to infinity, making for a universe that was unbounded and infinite; or like the surface of a pretzel, making for a universe that, like the surface of the sphere but far more interesting, was unbounded but finite. At present, the variant is largely discredited. Cosmologists have little evidence to suggest that the universe on large scales is curved and—from maps of the cosmic microwave background, that relic radiation from the big bang—persuasive evidence that it is flat.

  A second variant of the traditional model was the island universe. It held a finite amount of matter in an infinite space. Galaxies, our own among them, were huddled together in a large collection that thinned out at its edges and gradually gave way to an emptiness that extended to infinity. At present, however, astronomers have detected no “thinning out.” As far as their instruments can probe—nearly 42 billion light years out—they have found galaxies and stars made of the same stuff as galaxies and stars nearby, and behaving according to the same laws of gravity and motion. They see structures on the largest scales, bubbles of mostly empty space 300 million light years across with skins made of clusters and superclusters of galaxies, spread evenly, also as far. They have every reason to expect that such structures continue beyond the limits of their vision.

  So we are returned to the traditional model in its original form—a universe that is infinite, flat, and populated with galaxies and stars everywhere. It has many merits. It is the model of the universe with historical precedent and the model in agreement with observation. It is also the model in accord with what is called the “cosmological principle” or, more commonly, the “principle of mediocrity”—the working assumption of cosmologists, expanded and codified from Copernicus, that we are nowhere special.* Finally, the traditional model of the universe is also the default model—that is, the model used by cosmologists for most calculations and simulations. Yet for all this, it carries with it some rather bizarre implications.

  QUANTUM STATES

  Consider the following. First, only a finite number of particles can fit into a given volume of space before it collapses of its own weight into a black hole. Second, at any given moment, each of those particles can have only a finite number of positions and speeds, and all the particles in a given volume can be arranged in only so many ways.† Third, there is an infinite amount of space and an infinite number of volumes of that space. From these three straightforward and reasonable-sounding observations follows a rather startling conclusion: all possible arrangements of particles must be out there somewhere, and more mind-boggling still, all possible arrangements of particles must occur not just once, but an infinite number of times.

  In case you weren’t taking the principle of mediocrity personally, now you have a reason. Because one such arrangement is you. You have an infinite number of doppelgängers, the nearest of which is at a distance so great as to be unimaginable yet, strange to say, measurable. Physicist Max Tegmark, by calculating the number of particle arrangements in an appropriately sized volume of space and assuming that arrangements are distributed randomly, estimates that he or she (your doppelgänger, that is) is 10 to the power of 1029 (that is, 101029) meters away. It’s quite a distance. By way of comparison, the radius of our observable universe is far smaller—a mere 4 × 1026 meters.

  There is another consequence here, rather nearer our interests. Because all possible particle arrangements are realized somewhere, it follows that the weird life described in previous chapters must exist. Unless they violate some natural law, then no matter how improbable their biochemistry, the arsenic eaters, the ammonia drinkers, and the living dirigibles are also out there somewhere. And as with your doppelgängers, there must be an infinite number of each. The only qualification would concern their distribution. The less probable an organism, the fewer there would be in a given volume of space.

  MULTIVERSES

  This model of the universe, with doppelgängers, familiar life, weird life, and much, much else repeated through infinity, also contains an infinite number of observable universes, each overlapping others, each 84 billion light years across and growing outward in all directions one light year every year. Of course, in the sense that the space between them is continuous, they are not separate universes at all, but merely regions within one universe. When most cosmologists speak of alternate universes, parallel universes, and a multiverse, they have something else in mind: whole sets of universes, perhaps an infinite number, each as real and—strange to say—as infinite as the traditional model.

  On introduction, such an idea seems a bit untethered, and laypersons may be forgiven for suspecting it to be a late-night notion propped up with a few hypotheses hastily cobbled together the morning after. In fact, though, cosmologists and theoretical physicists have not been looking for multiverses. Quite the contrary: for reasons we’ll discuss shortly, many would prefer there were no such thing. But as string theorist and science writer Brian Greene notes, multiverses are turning out to be “harder to avoid than they are to find.”2

  THE QUANTUM MULTIVERSE

  Quantum mechanics is the theory describing the laws of physics that explain the universe on very small scales and underlie it on large scales. As theories go, it has been phenomenally successful—explaining the structure of atoms, radioactivity, superconductivity, the effects of electrical and magnetic fields, and the thermal and electrical properties of solids. It has also made possible the technologies of lasers, transistors, and electron microscopes. Since its beginnings more than half a century ago, not a single experiment has contradicted the predictions of quantum mechanics.* Yet peel away the skin of those predictions and you’ll find a mystery. Quantum physicists make testable predictions with a “quantum algorithm,” and they do not agree on its meaning; that is, they do not agree on exactly why the algorithm works. Thus, quantum mechanics comes with different approaches, all of which are attempts to explain the algorithm’s meaning and the uncertainty associated with a particle like an electron.

  The “many-worlds” approach, put forth in 1957 by then Princeton graduate student Hugh Everett III, states that subatomic activity continually creates new universes—or, as more recent proponents would have it, continually differentiates among identical copies of existing universes. These universes exist in what theoretical physicists call “another quantum branch i
n infinite-dimensional Hilbert space” and what science fiction authors call “another timeline.” At first, Everett’s work was neglected; in the late 1960s, however, physicist Bryce DeWitt dusted it off and presented it to larger audiences, emphasizing the many-worlds aspect. The approach might have been dismissed outright, but for the fact that it was competing against a weak field. Nobel Laureate physicist Steven Weinberg called it “a miserable idea except for all the other ideas.”3 For several decades a few theoretical physicists speculated about other universes, but most put all approaches aside and adopted an attitude that some called “shut up and calculate” and others (no doubt in need of a more respectable-sounding phrase) called “pragmatic instrumentalism.”

  Then, in the late 1970s, an Australian cosmologist and theoretical physicist named Brandon Carter turned his own instrumentalism to questions that were anything but pragmatic. He wondered how the universe might have been different had the laws of physics been other than what they are. He noted, as had several before him,* that if those laws had been much different, and in many cases only a little different, the universe would not have been able to support complex chemistry, let alone biochemistry or biology—or us.