Rollback (19 page)

Another couple, also out for a walk, was coming toward them. Don smiled at them as they passed.

"In fact," she continued, "you could argue there's even some evidence that we ourselves are precisely that: digital creations."

"I'm listening."

"There's a smallest possible length in our universe. The Planck length: 1.6 X 10
^-35
meters, or about 10
^-20
times the size of a proton, you can't measure a length any smaller than that, supposedly because of quantum effects."

"Okay."

"And," she said, "there must be a smallest unit of time, too, if you think about it: since a particle of light has to be either
here
, at Planck length unit A, or
next to it
, at Planck length unit B, then the time it takes to move from one unit to the next—the time it takes a photon to click over from being in
this
Planck space-unit to
that
Planck space-unit—is the smallest possible bit of time. And that unit, the Planck time, is 10
^-43
seconds."

"The Clock of the Short Now," said Don, pleased with himself.

"Exactly! But think about what that means! We live in a universe made up of discrete little bits of space that's aging in discrete little chunks of time—a universe that has pixels of distance and duration. We
are
digital at the most fundamental level."

"Quantum physics not as the basic nature of reality, but rather as the—how would you put it?—as a by-product of the level of resolution of our simulated world." He made an impressed face. "Cool."

"Thanks," she said. "But that means our world, with its pixels of time and space, might be nothing more than some far-advanced civilization's version of
The Sims
—and
that
would mean there's a programmer somewhere."

"I wonder what his email address is," Don said. "I've got some tech-support questions."

"Yeah, well, just remember once you open the seal on the universe, you can't get your money back." They turned a corner. "And speaking of making universes, with particle accelerators we may eventually be able to create daughter universes, budding off from this one. Of course, we won't create a full-blown universe, with stars and galaxies; we'd just create an appropriate singularity, like the one that our universe burst forth from in the big bang, and then the new universe will make itself from that. Physics says it's possible—and I rather suspect it's only a matter of time before someone successfully does it."

"I get it," said Don. "If you take a step back, that means
we
could be living in a universe created by a scientist in some parent universe's particle accelerator."

"Exactly!" said Sarah. "And, look, you know I love following all those debates in the U.S. about the teaching of evolution and intelligent design. Well, I'm an evolutionist—you know that—but I don't agree with the testimony that the scientists on the evolution side keep giving. They keep saying that science cannot admit supernatural causes, by which they mean that any scientific explanation has to, by definition, be limited to causes intrinsic to this universe."

"What's wrong with that?"

"
Everything
is wrong with it," she said. "That definition of science prevents us from ever concluding that
we
are the product of the work of other scientists, working in a reality above this one. It leaves us with the cockeyed mess of having a scientific worldview that on the one hand freely acknowledges that we will eventually be able to simulate reality perfectly, or maybe even create daughter universes, but on the other hand is constrained against ever allowing that we ourselves might exist in one of those things."

"Maybe science isn't interested in that question simply because it doesn't really answer anything," Don said. "I suspect somebody like Richard Dawkins would say, so what if we are the creation of some other intelligent being? That doesn't answer the question of where that other intelligent being came from."

"But science—and in particular, evolutionary science, which is Dawkins's forte—is largely about tracing lineages, and filling in the stages. If you took a comparable view of evolution, you'd have to say that wondering whether birds really evolved from dinosaurs is a dumb question to bother with, as is wondering whether Lucy was one of our ancestors, since the only truly interesting question is how the original, common ancestor of all life came into being. That's wrong; it's
one
interesting question, but it's hardly the only one worth asking. Whether we live in a created universe
is
an inherently interesting question, and it's worthy of scientific investigation. And if a creator does exist, or if a race becomes such a creator itself, that immediately raises the moral question of what, if any, accountability or obligation the creations have to that creator—and the flipside, and the part that I think we don't spend nearly enough time debating, which is what if any accountability or obligation our possible creator has to
us
."

Don took a big step sideways, and looked up at the dark sky. "Hey, God," he said, "be careful with your aim..."

"No, seriously," said Sarah. "Technology gives a species the power to prevent life, to create life, to take life on scales small and large; technology ultimately gives the power to be what we would call Gods, and, even if our definition of science is blind to it, it raises the possibility that what we are is the result of the work of some other being that would, by virtue of having created us, also deserve that term God. Doesn't mean we have to worship it—but it does mean that we, and any other technologically advanced race, will have to deal with ethical questions related both to potentially being Gods ourselves and potentially being the children of Gods."

They jogged across the street, beating an oncoming car. "And so the aliens from Sigma Drac wrote to us asking for our advice?" asked Don. He shook his head. "Heaven help them."
 

Sarah had said one of the appeals of becoming young again would be having time to read all the great books. Don couldn't quite say that the book he was looking at now—a thriller of the type that would have been sold in drug-store spinner racks when he'd been young the first time—was great, but it was a pleasure to be able to read for hours without getting eye fatigue, and without having to put on his cheaters. Still, eventually, he did get bored with the book, and so he had his datacom scan the TV listings for anything that might interest him, and—

"Hey," he said, looking up from the list the device had provided, "Discovery is showing that old documentary about the first message."

Sarah, seated on the couch, looked over at him; he was leaning back in the chair. "What old documentary?" she said.

"You know," he said, a little impatiently, "that hour-long thing they did when you sent the initial reply to Sigma Draconis."

"Oh," said Sarah. "Yeah."

"Don't you want to watch it?"

"No. I'm sure we've got a recording of it somewhere, anyway."

"Doubtless in some format we can't read anymore. I'm going to put it on."

"I wish you wouldn't," she said.

"Oh, come on!" said Don. "It'll be fun." He looked at the panel above the fireplace. "TV on; Discovery Channel." The picture was razor-sharp and the colors vibrant. Don had forgotten they'd had high-definition TV that long ago; he found lots of older shows unwatchable now, because they'd been videotaped in low-res.

The documentary was already under way. Some aerial footage of the Arecibo radio telescope was being shown, and the voice of a Canadian actor—was it Maury Chaykin?—was doing the narration. Soon, that was replaced with a potted history of SETI: the Drake equation, Project OZMA, the
Pioneer 10
plaque, the
Voyager
records—which, it was duly noted, this being the Canadian version of Discovery Channel, had been designed by Toronto's own Jon Lomberg. Don had forgotten how much of the documentary
wasn't
about Sarah and her work. Maybe he'd go into the kitchen to get a drink, and—

And suddenly, there she was, on the screen, and—

And he looked over at his wife, seated on the couch, then back at the monitor, then shifted his gaze between the two once more. She was steadfastly staring at the fireplace, it seemed, not the magphotic panel above it, and she was red in the face, as if embarrassed, because—

Because she looked so much younger, so much less frail, on the monitor. After all, this had been recorded thirty-eight years ago, back when she was forty-nine. It was a sort of rollback, a regressing to a younger state; oh, to be sure, not nearly as far back as he had gone, but still a bitter taste of what might have been.

"I'm sorry, sweetheart," he said, softly, and then, more loudly, into the air: "TV off."

She looked over at him, her face expressionless. "I'm sorry, too," she said.
 

As the day wore on, Sarah went up to Carl's old room, to work through the giant stack of papers Don had brought her from the University.

Don, meanwhile, went down to the basement. He and Sarah had almost given up on using the rec room as they'd gotten older. The stairs down to it were particularly steep, and there was a banister only on the wall side. But he now had no trouble going down there, and, on these hot summer days, it was the coolest place in the house.

Not to mention the most private.

He sat on the old couch there, and looked about, a fluttering in his stomach. History had been made here. Right over there, Sarah had figured out the meat of the original message. And history might be made in this house again, if she could decrypt the Dracons' latest transmission. Perhaps someday there'd be a plaque on their front lawn.

Don was holding his datacom tightly in his hand, and its plastic shell was now moist with his perspiration. Although he'd fantasized about seeing Lenore again, he knew that could never happen. But she'd made him promise to call, and he couldn't just ignore her, couldn't leave her hanging. That would be wrong, mean, petty. No, he had to call her up and say good-bye properly. He'd tell her the truth, tell her there was someone else.

He took a deep breath, let it out slowly, opened the datacom, snapped it immediately shut, and then, at last, opened it once more, gingerly, as though lifting the lid on a coffin.

And he spoke to the little device, telling it who he wanted to contact, and—

Rings. The tolling of a bell. And then—

A squeaky voice. "Hello?"

"Hi, Lenore," he said, his heart jackhammering. "It's Don."

Silence.

"You know, Don Halifax."

"Hello," Lenore said again, this time her tone icy cold.

"Look, I'm sorry I haven't called you, but..."

"It
has
been three days."

"Yes, I know, I know, and I'm sorry. I really did mean to call. I didn't want you to think I was one of those guys who ... well, you know, one of those guys who doesn't call."

"Could have fooled me," she said,

He cringed. "I'm sorry. You deserve way better—"

"Yes, I do."

"I know. But, look, I—"

"Didn't you have a good time?"

"I had a great time," he said. And he had—just about the only time he'd been happy for weeks now. Not just the sex, but just being with someone who could keep up with him, and—

Lenore sounded relieved. "Good. 'Cause, I did too. You ... you're really something."

"Um, thanks. So are you. But, um..."

"Look," she said, her tone conveying that she was making a special dispensation, "I'm busy at the food bank tomorrow. But I'm free on Sunday. Maybe we could get together then?"

No
, thought Don.

"What did you have in mind?" he said, astonished to hear himself speak the words.

"The forecast says it's going to be gorgeous. Why don't we go down to Centre Island?"

I cannot do this
, he thought.
I will not do this.

"Don?" said Lenore, into what had become an uncomfortable silence.

He closed his eyes. "Sure," he said. "Sure, why not?"
 

Don had arrived at the ferry docks at the foot of Bay Street about ten minutes early, and he kept scanning the crowds, looking for—

Ah, there she was: the rare and radiant maiden whom the angels named Lenore. She came running over to him, in white short-shorts and a loose-fitting white top, clutching a giant sun hat. She stretched up and kissed him quickly on the mouth, and then pulled back, smiling, and—

And he was stunned. In his mind, he'd aged her forward: he'd been picturing her as being in her mid-thirties, which seemed a more appropriate age for someone he might want to talk to, but here she was, freckled and fresh-faced, looking ten years younger than that.

They boarded the
Max Haines
, a white, double-decker ferry, and took the kilometer-and-a-half journey to Centre Island, with its boardwalks, beaches, amusement park, and gardens.

Lenore had wanted to come down here, she said, because she missed the water. But the result was not proving entirely satisfactory: gulls eating garbage were no substitute for Vancouver's great blue herons, and, besides, there was no salt tang to the air. Once they'd docked, they jogged for about half an hour. Don found that exhilarating, and he loved to feel his hair—yes, hair!—whipping in the breeze.

After that, they just strolled along a paved walkway, gingerly trying to avoid all the goose droppings. Off to their right was the bay, and across it was Toronto itself, with the skyline that Don had watched grow and spread over the better part of a century. It was still dominated by the CN Tower, once, but certainly no longer, the tallest freestanding structure in the world; as a teenager, he had gone downtown with his friend Ivan to watch a Sikorsky Skycrane assemble its huge components. Blockish skyscrapers, like the elements of a bar chart, trailed off left and right from the Tower. He recalled when Toronto's downtown had been a tiny cluster of tall buildings, but now it went on and on along the lakeshore, west toward Mississauga, and east until the Scarborough Bluffs forced it to stop.