"Those are the only two choices, right?" Heather says. "Like most people believe in one or other of those two?"
"Yeah, I think so," I say. "I think most people favor the Copenhagen interpretation, though."
"So how does this relate to the big bang?"
"Well," I say. "If you imagine the primordial particle: the thing that went 'bang' fourteen billion years ago ... That particle should be just like any other particle. It would have its own wavefunction—a series of probabilities about where it was and what it was doing. So what we know of quantum physics suggests that unless an external observer showed up and observed the exact state of the particle, its wavefunction would not collapse. In other words, it would exist in a state of all the different probabilities at once. It would be both fast and slow, moving left and right, here and over there all at once. An observer external to the universe must be God. So perhaps God collapsed the wavefunction that became the universe. In other words, out of all probabilities God collapsed the original particle into one universe, in which we now live. That's the Copenhagen interpretation applied to the original particle. If you reject that, you're left with the many-worlds interpretation, which would suggest that there is no external observer and no collapse. Instead, all the probabilities exist 'out there'—every possible universe you could think of exists alongside this one: some hot, some cold, some with people, some without, some that create their own 'baby universes' and some that don't..."
Heather groans. "I knew there was a reason I'd forgotten this stuff."
"What if you reject this quantum physics?" asks Adam.
"Then I guess your CD player and credit cards stop working."
"I don't have a CD player or a credit card."
I grin at him. "Yes, but you know what I mean. Real technology is built on quantum physics. Engineers have to learn it. I mean, it is nuts, but it works out there in the real world."
"God or the multiverse," says Heather. "Which one would you choose?"
"I'm not happy with either of them," I say. "But probably God—whatever that actually means. Call it the Thomas Hardy interpretation: I'd rather have something out there that means something than feel like I exist in a vast ocean of pure meaninglessness."
"What about you, Adam?"
"God," he says. "Even though I thought I'd given all that up." He smiles without showing his teeth, as if doing more with his mouth would break his face. "No, it does make sense: the idea of an external consciousness. I prefer that anyway, given this choice."
"Oh well, I'm on my own then with the multiverse," says Heather.
"You're never alone in the multiverse," I say.
"Ha ha," she says. "Seriously, I can't believe that God made life, not with the research I'm doing. I mean the evidence just isn't there. And I get so many threatening letters from creationists that I just can't align myself to them in any way."
"I don't think this means aligning yourself with creationists," I say. "Surely some external being could have sparked the very beginning of the universe and then everything else just evolved as scientists think it did."
Although as I say this I think: via Newtonian cause and effect, and I realize that this is at odds with the idea of a quantum universe, and I suddenly don't know what to say.
"What is your research exactly?" asks Adam.
"Looking for LUCA," she says. "Well, that's how the headlines put it whenever science journalists write about it. LUCA stands for Last Universal Common Ancestor. In other words, searching for the mother of us all."
"She's got this computer model," I say. "You have to see it next time you're in the office. I didn't understand it when I looked at it, but it still gave me the shivers somehow."
"The universal mother," says Adam. "Interesting."
"Don't tell me—you're thinking like the Garden of Eden, with...," she begins.
"No, no. The great mother. The beginning of everything. The Tao is called the Great Mother: Empty yet inexhaustible, it gives birth to infinite worlds. That's from the Tao Te Ching."
"Oh," says Heather. "Well, that's just as bad. Who wants pudding?"
Chapter Twelve
After pudding—baked apricots with honey, cashew nuts, and brandy—and a long conversation about LUCA, and some other entity called FLO (the first living organism), Adam and I thank Heather and leave together, trying not to slip on the frosty pavement.
After we are out of earshot of the house, Adam laughs.
"What?" I say.
"Well, I didn't like to say, but I'm not sure I care about which type of bacteria we evolved from."
"Biologists do always tend towards the most depressing explanations for things," I say. "I wasn't convinced by Heather's reaction to my idea about machine consciousness, either."
"No. She likes the status quo, I think."
"I think so, too. But I don't see what's wrong with the argument. At some point animals evolved from plants and conscious life was formed. What is consciousness? Obviously it's made from the same quarks and electrons as everything else, perhaps just arranged in a different way. But consciousness is obviously something that can evolve. Samuel Butler said as much in the nineteenth century. If human consciousness could evolve from nothing, then why can't machine consciousness do the same thing?"
There are obvious objections to this idea, some of which Heather did point out. For example: What if consciousness can only exist in organic life-forms? But what is an organic life-form? Machines can self-replicate. They're made from carbon. They need fuel, just like we do.
"Unless consciousness isn't made from matter," says Adam.
"Yeah, well that's possible, too," I say. "But I do sometimes wonder: If a computer read every book in the whole world, would it eventually start to understand language?"
"Hmm," says Adam. Then, after a long pause: "It's cold."
"Yeah. I'm freezing."
It's almost silent as we walk towards the city center. It's past midnight and as we approach the cathedral the only sounds I can hear are the distant humming noises of trucks outside shops; the creaking sound of men unloading blouses and sandwiches and packaged salads and coffee beans and newspapers so they can appear in the shops to-morrow, as if they came to be there by magic.
"Do we know each other?" Adam suddenly asks.
I pause, and then say: "In what sense?"
"I mean I thought I knew you when I saw you earlier today."
I take a deep breath: cold air in my lungs. "I thought the same thing."
"But I don't know you. I'm sure of it."
"Well..." I shrug. "Perhaps we did meet before and forgot."
"I wouldn't forget. I wouldn't forget meeting you."
"Adam...," I start.
"Don't say anything," he says. "Just look."
We're just walking past the cathedral gates. If you stop and look up where Adam's pointing now you can see Jesus looking down on you, carved in stone.
"It is amazing," I say, without thinking. "Even if you don't believe in all the rest of it, Jesus is a remarkable figure." Then I laugh. "That sounded so stupid and banal. Sorry. I'm sure no one even disagrees with that."
"You'd be surprised," Adam says.
"Oh," I say, suddenly remembering standing in the same spot earlier on, but looking at the gates, rather than up at Jesus. "Do you know anything about holy water?"