“A splitting of the timeline,” said Mary, leaning her [371] bum against the arm of a vinyl-padded chair in the lounge.

  “Oui,” said Louise. “Well, I spent some time talking to Ponter about this.”

  “Ponter mentioned that,” said Mary. “I must have missed it.”

  “It was late at night, and—”

  “You went into Ponter’s room again after we’d finished the language lessons?” Mary was astonished by the rush of—of, my God, of jealousy—she felt.

  “Sure. I like to be up at night; you know that. I wanted to learn more about the Neanderthal view of physics.”

  “And?” said Mary, trying to keep her tone even.

  “Well, it’s interesting,” said Louise. She took a sip of her coffee. “Here in this world, we’ve got two major interpretations for quantum mechanics: the Copenhagen interpretation and Everett’s Many-Worlds interpretation. The former postulates a special role for the observer—that consciousness actually influences reality. Well, that idea makes some physicists very uncomfortable; it’s seen as a return to vitalism. Everett’s Many-Worlds interpretation was an attempt to work around that. It says that quantum phenomena cause new universes to split off constantly, with each possible outcome of a quantum interaction occurring, but in a separate universe. No observers are required to shape reality; instead, every reality that can conceivably exist is automatically created.”

  “Okay,” said Mary, not because she really understood, but because the alternative seemed to be an even longer lecture.

  “Well, Ponter’s people have a single theory of quantum mechanics that’s sort of a synthesis of our two theories. It [372] allows for many worlds—that is, for parallel universes—but the creation of such universes doesn’t result from random quantum events. Rather, it only happens through the actions of conscious observers.”

  “Why don’t we have the same single theory, then?” asked Mary, munching on a particularly large chip.

  “Partly because there’s a lot of math that seems irreconcilable between the two interpretations,” said Louise. “And, of course, there’s that old problem of politics in science: those physicists who favor the Copenhagen interpretation have devoted their careers to proving that it’s right; same thing for the guys on Everett’s side. For them all to sit down and say, ‘Maybe we’re both partly right—and both partly wrong’ just isn’t going to happen.”

  “Ah,” said Mary. “It’s like the Regional Continuity versus Replacement debate in anthropology.”

  Louise nodded. “If you say so. But suppose the Neanderthal synthesis of quantum physics is actually correct. It implies that consciousness—human volition—has the power to spin off new universes. Well, that raises a significant question. Presumably in the beginning, at the moment of the big bang, there must have been only one universe. Sometime later, it started splitting.”

  “I thought Ponter didn’t believe in the big bang?” said Mary.

  “Yes, apparently Neanderthal scientists think the universe has always existed. They believe that on large scales, redshifts—which are our principal evidence for an expanding universe—are proportional to age, rather than distance; that is, that mass varies over time. And they think the gross structure of galaxies and galactic clusters are [373] caused by monopoles and plasma-pinching magnetic vortex filaments. Ponter says the cosmic microwave background—which we take as the residue of the big-bang fireball—is really the result of electrons trapped in these strong magnetic fields absorbing and emitting microwaves. Repeated absorption and emission by billions of galaxies smoothed out the effect, he says, producing the uniform background we detect now.”

  “Does that seem possible to you?” asked Mary.

  Louise shrugged. “I’m going to have to look into it.” She took another sip of coffee. “But, you know, after telling me all that, Ponter said the most astonishing thing.”

  “What?” asked Mary.

  “I guess you showed him a church service, right?”

  “Yes. On TV.”

  Louise took a seat on one of the other vinyl-covered chairs. “Well,” she said, “apparently he spent some time that night watching Vision TV, soaking up more religious thought. He said our story of the universe having an origin is just a creation myth, like from the Bible. ‘In the beginning God created the Heavens and the Earth ...’ and all that. ‘Even your science,’ Ponter said, ‘is contaminated by this error of religion.’ ”

  Mary sat down properly as well. “You know ... I mean, physics is your field, not mine, but maybe he’s right. I mentioned Regional Continuity versus Replacement a moment ago; sometimes that’s called Multiregionalism versus Out-of-Africa. Anyway, there are those who’ve observed that Replacement, which is what I and other geneticists favor, is also basically a biblical position: humanity came full-blown out of Africa, ejected from a garden, and there’s a [374] hard-and-fast line between us and everything else in the animal kingdom, including even other contemporaneous members of the genus Homo.”

  “It’s an interesting point of view,” said Louise.

  “And you can argue that the other side is fighting for a biblical interpretation, too: the parallels between Multi-regionalism and the Ten Lost Tribes of Israel are pretty blatant. Beyond that, there’s the whole ‘mitochondrial Eve’ hypothesis—that all modern humans trace their origin to one woman who lived hundreds of thousands of years ago. Even the theory’s name—Eve!—screams that it’s being pushed more because of biblical resonances than because it’s good science.” Mary paused. “Anyway, sorry, you were talking about the Neanderthal version of quantum physics ...”

  “Right, right,” said Louise. “Well, my thought was, suppose they are correct about how parallel universes are spun off, but wrong about this universe having existed forever. If the universe did have a beginning, then when did that first split occur?”

  Mary frowned. “Well, umm, I don’t know. I guess the first time somebody made a decision.”

  “Exactly! I think that’s exactly right! And when was the first decision made?” Louise paused. “You know, it is interesting what Ponter says about how our scientific worldview is always, down deep, trying to say the same things our creation myths say—the big bang and your model of hominid evolution both being modern retellings of Genesis. Well, maybe I’m being guilty of the same kind of thinking here. After all, in the Bible, the first decision made by anyone other than God is when Eve decided to take the [375] apple—the original sin—and, well, one could think of that as having split the universe. In one timeline, the one we’re supposedly in, humanity was cast out of paradise. In another, we weren’t. In fact, it’s even a bit like Ponter’s own case, with a being crossing over from one version of reality to the other.”

  Mary was completely lost. “How do you mean?”

  “I’m talking about Mary—not you, Professor Vaughan; Mary, the mother of Jesus. You’re a Catholic, aren’t you?”

  Mary nodded.

  “I noticed your crucifix.” Mary looked down, self-conscious. “I’m Catholic, too,” continued Louise. “Anyway, as a Catholic, you probably don’t make the same mistake lots of other people do. The doctrine of the immaculate conception—a lot of people think that’s a fancy term for Christ’s virgin birth, but it isn’t, is it?”

  “No,” said Mary. “No, it refers to the conception of Mary herself. The reason she was able to give birth to the son of God was that she herself was conceived devoid of original sin—it was her conception that was immaculate.”

  “Exactly. Well, how do you get a person without original sin in a world in which everyone is descended from Adam and Eve?”

  “I have no idea,” said Mary, truthfully.

  “Don’t you see?” said Louise. “It’s as if Mary was shifted into this universe from the other timeline, from the one in which Eve never took the apple, the one in which Man never fell, the one in which people live without the taint of original sin.”

  Mary nodded dubiously. “One could arg
ue that.”

  Louise smiled. “Well, you’ll see the parallel between [376] Ponter and the Virgin Mary in a second. Let me get back to my earlier question: I said if he’s right, and the universe does split every time a decision is made, when did the universe first split? And you said the first time someone made a decision. But when was that? Not in the Bible, but, well, in reality ... ?”

  Mary fished out another potato chip. “Gee, I don’t know. The first time a trilobite decided to go left instead of right?”

  Louise put her cardboard coffee cup down on a little table. “No, I don’t think so. Trilobites have no volition; they, and all other primitive forms of life, are just chemical machines. Stephen Jay Gould keeps talking about rewinding the tape of life in his books and getting a different outcome, and when he says that, he thinks he’s making an allusion to chaos theory. But he’s wrong. No matter how many times you placed a trilobite at the same fork in the road, it will go the same way. A trilobite doesn’t think; it doesn’t have consciousness. It just processes the inputs of its senses and does what they dictate. No choice is made. Gould is right—sort of—that if the initial conditions were changed, the outcome could be radically different, but rewinding the tape of life and playing it again no more gives a different outcome than rewinding a tape of Gone with the Wind and playing it again results in an ending in which Rhett and Scarlett stay together. I don’t think real decisions—real choices, real consciousness—emerged until much, much later. I think we—Homo sapiens—were the first conscious beings on this planet.”

  “There was lots of sophisticated behavior by earlier forms of humans,” said Mary. “Homo ergaster, Homo erectus, [377] Homo habilis, even the australopithecines and Kenyanthropus.”

  “Well, I realize this is your field, Professor Vaughan—” Had she really in all the time they’d spent quarantined together never volunteered that Louise could call her Mary?—“but I’ve been reading up on this on the Web. As far as I can tell, those earlier kinds of man didn’t really have behavior any more sophisticated than a beaver building a dam.”

  “They made tools,” said Mary.

  “Oui” said Louise. “But weren’t they repetitive, virtually identical tools, turned out over the centuries by the thousands? All made to the same mental template, the same design?”

  Mary nodded. “That’s true.”

  “Surely there has to be some natural variation among stone tools,” said Louise, “just based on chance accidents and random differences that occur when implements are chipped from stone. If there was consciousness at work, even without coming up with a better idea on their own, early humans should have seen that some tools happened to be better than others. It’s like you don’t have to think of the round wheel right off the bat; you might start with a five-sided one, then accidentally make a six-sided one—and note that it rolled slightly better. Eventually, you’d come up with the perfectly round one.”

  Mary nodded.

  “But if there’s no consciousness at work,” said Louise, “you simply toss aside the better version as not fitting your mental template of what was supposed to be produced. Right? And that’s what happens with the tools in the [378] archeological record: instead of gradual refinement over time, they just stay the same. And the only explanation I can think of for that is that there was no conscious selection of better variants: the toolmaker simply wasn’t aware, he couldn’t see that this particular way of hitting nodules produced something better than that way. The design was frozen.”

  “Interesting take,” said Mary, genuinely impressed.

  “And when we see complex repetitive behavior in other animals—such as building a dam—we call it instinct, and that’s what that kind of toolmaking was. No, until Homo sapiens, there was no consciousness, and—here’s the kicker—in fact, for the first sixty thousand years that Homo sapiens existed, there was no consciousness.”

  “What are you talking about?” said Mary.

  “When did anatomically modern humans first appear?” asked Louise, picking up her coffee cup again.

  “About one hundred thousand years ago.”

  “That’s the same figure I saw on the web. Now, do I understand that right? A hundred-K years in the past, creatures that looked exactly like us, that walked exactly like us, first appeared, right? Creatures with brains that were the same size and shape as our brains, judging by their cranial cavities?”

  “That’s right,” said Mary. She’d finished her chips, and got some Kleenex out of her purse so she could wipe her greasy fingers.

  “But,” said Louise, “according to what I read, for sixty thousand years, they thought no thoughts. For sixty thousand years, they did nothing that wasn’t instinctual. But then, forty thousand years ago, everything changed.”

  [379] Mary’s eyes went wide. “The Great Leap Forward.”

  “Exactly!”

  Mary felt her heart pounding. The Great Leap Forward was the term some anthropologists gave to the cultural awakening that occurred 40,000 years ago; others called it the Upper Paleolithic Revolution. As Louise had said, modern-looking human beings had been around for six hundred centuries by that point, but they created no art, they didn’t adorn their bodies with jewelry, and they didn’t bury their dead with grave goods. But starting simultaneously 40,000 years ago, suddenly humans were painting beautiful pictures on cave walls, humans were wearing necklaces and bracelets, and humans were interring their loved ones with food and tools and other valuable objects that could only have been of use in a presumed afterlife. Art, fashion, and religion all appeared simultaneously; truly, a great leap forward.

  “So you’re saying that some Cro-Magnon 40,000 years ago suddenly started making choices, and the universe started splitting?”

  “Not exactly,” said Louise. She’d evidently finished her first coffee; she got up and bought a second one. “Think about this: what caused the Great Leap Forward?”

  “Nobody knows,” said Mary.

  “For all intents and purposes, it’s a marker, right there in the archeological record, showing the dawn of consciousness, wouldn’t you say?”

  “I suppose,” said Mary.

  “But that dawning isn’t accompanied by any gross physical change; it’s not like a new form of humanity appeared who suddenly started making art. Brains capable of [380] consciousness had existed for sixty thousand years, but they weren’t conscious. And then something happened.”

  “The Great Leap Forward, yes. But, as I said, no one knows what caused it.”

  “You ever read Roger Penrose? The Emperor’s New Mind?”

  Mary shook her head.

  “Penrose is an Oxford mathematician. He contends that human consciousness is quantum-mechanical in nature.”

  “Meaning what?”

  “Meaning that what we think of as intelligence, as sentience, doesn’t arise from some biochemical network of neurons, or anything as crude as that. Rather, it arises from quantum processes. Specifically, he and an anesthesiologist named Hameroff argue that quantum superposition of isolated electrons in the microtubules of brain cells creates the phenomenon of consciousness.”

  “Ah,” said Mary dubiously.

  Louise sipped some of her new coffee. “Well, don’t you see?” she said. “That explains the Great Leap Forward. Sure, our brains had been just as they are today since one hundred thousand years ago, but consciousness didn’t begin until a quantum-mechanical event occurred, presumably at random: the one and only spinning off of a new universe that happened the way Everett thinks it does.”

  Mary nodded; it was an interesting notion.

  “And quantum events, by their very nature, have multiple possible outcomes,” said Louise. “Instead of that quantum fluctuation, or whatever it was, creating consciousness in Homo sapiens, the same thing might have happened in [381] the other kind of humanity that existed 40,000 years ago—Neanderthal man! The first splitting of the universe was an accident, a quantum fluke. In one branch, thought and cognition arose
in our ancestors; in another, it arose in Ponter’s ancestors. I read that Neanderthals had been around since maybe 200,000 years ago, right?”

  Mary nodded.

  “And they had even bigger brains than we did, right?”

  Mary nodded again.

  “But on this world,” said Louise, “in this timeline, those brains never sparked with consciousness. Ours did instead, and the edge that consciousness gave us—cunning and foresight—led to us absolutely triumphing over the Neanderthals, and becoming rulers of the world.”

  “Ah!” said Mary. “But in Ponter’s world—”

  Louise nodded. “In Ponter’s world, the opposite happened. It was Neanderthals who became conscious, developing art and culture—and cunning; they took the Great Leap Forward while we remained the dumb brutes we’d been for the preceding sixty thousand years.”

  “I suppose that’s possible,” said Mary. “You could probably get a good paper out of that.”

  “More than that,” said Louise. She sipped some more coffee. “If I’m right, it means Ponter might get to go home.”

  Mary’s heart fluttered. “What?”

  “I’m basing this in part on stuff Ponter told me, and in part on our own world’s understanding of physics. Suppose that each time the universe splits, it doesn’t do it the way amoebas do—with one amoeba becoming two daughters, and the parent disappearing in the process. Suppose [382] instead it happens more like vertebrates giving birth: the original universe continues on, and a new daughter universe is created.”

  “Yes?” said Mary. “So?”

  “Well, then, you see, universes actually are of different ages. They might appear absolutely identical, except for your choice of breakfast this morning, but one of them is twelve billion years old, and the other is”—she looked at her watch—“well, a few hours old now. Of course, the daughter universe would seem to be billions of years old, but it wouldn’t really be.”

  Mary frowned. “Umm, Louise, you’re not by any chance a creationist, are you?”