But, said Louise, according to what I read, for sixty thousand years, they thought no thoughts. For sixty thousand years, they did nothing that wasnt instinctual. But then, forty thousand years ago, everything changed.
Marys 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 didnt adorn their bodies with jewelry, and they didnt 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 youre saying that some Cro-Magnon 40,000 years ago suddenly started making choices, and the universe started splitting?
Not exactly, said Louise. Shed 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, its a marker, right there in the archeological record, showing the dawn of consciousness, wouldnt you say?
I suppose, said Mary.
But that dawning isnt accompanied by any gross physical change; its not like a new form of humanity appeared who suddenly started making art. Brains capable of consciousness had existed for sixty thousand years, but they werent 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 Emperors 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, doesnt 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, dont 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 didnt 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 the other kind of humanity that existed 40,000 years agoNeanderthal 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 Ponters 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 uscunning and foresightled to us absolutely triumphing over the Neanderthals, and becoming rulers of the world.
Ah! said Mary. But in Ponters world
Louise nodded. In Ponters world, the opposite happened. It was Neanderthals who became conscious, developing art and cultureand cunning; they took the Great Leap Forward while we remained the dumb brutes wed been for the preceding sixty thousand years.
I suppose thats possible, said Mary. You could probably get a good paper out of that.
More than that, said Louise. She sipped some more coffee. If Im right, it means Ponter might get to go home.
Marys heart fluttered. What?
Im basing this in part on stuff Ponter told me, and in part on our own worlds understanding of physics. Suppose that each time the universe splits, it doesnt do it the way amoebas dowith one amoeba becoming two daughters, and the parent disappearing in the process. Suppose 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 isshe looked at her watchwell, a few hours old now. Of course, the daughter universe would seem to be billions of years old, but it wouldnt really be.
Mary frowned. Umm, Louise, youre not by any chance a creationist, are you?
Quoi? But then she laughed. No, no, nobut I see the parallel youre alluding to. No, Im talking real physics here.
If you say so. But how does this get Ponter home?
Well, assume this universe, the one you and I are in right now, is the original one in which Homo sapiens became consciousthe one that initially split from the universe in which Neanderthals became conscious instead. All the other googolplex of universes in which conscious Homo sapiens exist are daughters, or granddaughters, or great-great-great-great-granddaughters, of this one.
Thats a huge assumption, said Mary.
It would be, if we had no other evidence. But we do have evidence that this particular universe is specialPonters arrival here, out of all the places he might have gone. When Ponters quantum computer ran out of universes in which other versions of itself existed, what did it do? Why, it reached across to universes in which it didnt exist. And, in doing so, it latched first onto the one that had initially split from the entire tree of those in which it did exist, the one that, forty thousand years previously, had started on another path, with another kind of humanity in charge. Of course, as soon as it reached a universe in which a quantum computer didnt exist in the same spot, the factoring process crashed and the contact between the two worlds was broken. But if Ponters people repeat the exact process that led to him being marooned here, I think theres a real chance that the portal to this specific universe, the one that first split from their timeline, will be re-created.
Thats a lot of ifs, said Mary. Besides, if they could repeat the experiment, why havent they already?
I dont know, said Louise. But if Im right, the doorway to Ponters world may open again.
Mary felt her stomach flutteringand not just because of the potato chipsas she tried to sort out her feelings about that possibility.
Chapter 43
Adikor Huld stared at the mining robot Dern had provided. It was a sorry-looking contraption: just an arrangement of gears and pulleys and mechanical pincers, vaguely resembling a stubby pine tree denuded of needles. The robot had obviously endured a fire at some point; there had been one in the mine about four months ago, Adikor recalled. Some of the robots components had fused, some metal parts were extensively fatigued, and the whole thing had a blackened, sooty look to it. Dern had said this unit was to have been sent to the recycling yards, anyway, so no one would mind if it were lost.