text: Saturday morning always meant pancakes and sausages in the Decter household. Now that they were living in Waterloo, the sausages were, of course, Schneider's brand, and the syrup was real maple syrup Caitlin's mom had bought from Mennonites in the nearby town of St. Jacob's.
  
  "I was up at 5:00 a.m.," Caitlin's dad said, as soon as they'd started eating.
  
  "There's a 5:00 a.m.?" Caitlin joked.
  
  "I set up a workspace for you and Professor Kuroda in the basement," he continued.
  
  "Thank you, Dr. Decter," Kuroda said, sounding relieved— apparently everybody but the Hoser was worried about her virtue! But she guessed it probably would be more comfortable downstairs than in her bedroom.
  
  "Oh, for Pete's sake!" her mom said. "You're staying in our house; you can call him Malcolm."
  
  Her father neither confirmed nor denied this assertion, Caitlin noted. Instead, he said, "I bought a new computer at Future Shop yesterday. It's set up downstairs for the two of you; I put it on the household network."
  
  "Thank you," she said. "And I have some news of my own—I saw the lightning last night."
  
  The words were simultaneous, overlapping. Her dad, matter-of-fact: "Your mother told me." And Kuroda, amazed: "You saw lightning?"
  
  "That's right," Caitlin said.
  
  "What—what did it look like to you?" Kuroda said.
  
  "Jagged lines against darkness. Bright lines—white, right? Stark against a pure black background."
  
  Kuroda was clearly eager to look at the data from the eye-Pod: he had only one extra helping of pancakes.
  
  Caitlin had been in the basement just a few times in the three months they'd lived in this house, mostly back in August, when it had been surprisingly hot and muggy outside—almost like Texas. The basement had been cool then (and still was), and although her mother had complained about how little light there was down there—apparently, just a single bulb in the middle of the room—it hadn't bothered Caitlin.
  
  "What's the 4-1-1?" she asked, hands on hips.
  
  Kuroda's English was excellent, but the information number must be different in Japan. "Sorry?"
  
  "What's the setup? Tell me about the room."
  
  "Ah. Well, it's an unfinished basement—I suppose you know that. Bare insulation between the slats; cement floor. There's an old TV—the kind with a picture tube—and some bookcases. And your dad has set up the new computer on one of those worktables with metal folding legs; it's pushed up against the far wall, the one opposite the staircase. The computer is a minitower, and he's got an LCD screen attached to it. There's a little window above the table and a couple of comfortable-looking swivel chairs in front of it."
  
  "Sweet! I wonder where he got the chairs."
  
  "They have a logo on them—kind of like the Greek letter pi."
  
  "Oh, he borrowed them from work. Speaking of which, let's get to it."
  
  Kuroda helped guide her to one of the chairs, and he settled into the other; she could hear it squeaking a bit. "Let me log on to my servers in Tokyo," he said. "I want to examine the datastream you sent them during the lightning storm—see if we can isolate what it was that caused your primary visual cortex to respond."
  
  She could hear him typing away and, as he did, she realized she'd forgotten to mention something over breakfast. "After the lightning flashes," she said, "webspace looked different."
  
  "Different how?"
  
  "Well, I could still see the structure of the Web clearly, like before, but the … the background, I guess, was different."
  
  He stopped typing. "What do you mean?"
  
  "It used to be dark. Black, I guess."
  
  "And now?"
  
  "Now it's, um, lighter? I could see details in it."
  
  "Details?"
  
  "Yeah. Like—like …" She struggled to make the connection; the pattern did remind her of something she was familiar with, but—got it! "Like a chessboard." She had a blind person's chessboard, with squares that were alternately raised and lowered, and Braille initials on the top of each piece; she sometimes played her dad. "But, um, not quite. I mean, it was made of lighter and darker squares, but they're not in the same pattern as a chessboard, and they go on, like, forever."
  
  "How big are they?"
  
  "Tiny. If they were any tinier, I don't think I could see them. In fact, I can't swear that they were squares, but they were packed tightly together and made rows and columns."
  
  "And there were thousands of them?"
  
  "Millions. Maybe billions. They're everywhere."
  
  Kuroda sat as quietly as was possible for him, then: "You know, human vision is made of pixels, just like a computerized image. Each axon in the optic nerve provides one picture element. Now, most people aren't conscious of them, but if you have decent focus, and you look at a blank wall, some people can see them. Your brain is processing Web information as if it were coming from your eye; it may be hardwired to see it all as a mesh of pixels at the limits of resolution, but …"
  
  He trailed off. After ten seconds she prodded him.
  
  "But?"
  
  "Well, I'm just thinking. You've described seeing circles, which we've taken to be websites, and lines connecting them, which we've assumed represent hyperlinks. And that's it—that's the World Wide Web, right? That's all of it. So, what could make up the background to the Web? I mean, in human vision, the—"
  
  "Don't say that."
  
  "Pardon?"
  
  " 'Human vision.' Don't say that. I'm human."
  
  A sharp intake of breath. "I'm so sorry, Miss Caitlin. May I say 'normal' vision?"
  
  "Yes."
  
  "All right. In normal vision, the background is—well, it's the distant reaches of the universe if you're looking up at the night sky. But what would be the background for the Web?"
  
  "Background radiation?" she suggested. "Like the cosmic microwave background?"
  
  Kuroda was quiet for a moment. "How old are you again?"
  
  "Hey," she said, "my father is a physicist, you know."
  
  "Well, the cosmic microwave background is uniform to a fraction of a degree in all directions. But what you're seeing is mottled in black and white, you say?"
  
  "Yeah. And it keeps shifting."
  
  "Pardon?"
  
  "Shifting. Changing. Didn't I mention that?"
  
  "No. What do you mean precisely?"
  
  Something brushed against her legs—ah, Schrödinger! Caitlin scooped him up into her lap. "The dark squares switch to light, and the light ones to dark," she said.
  
  "How rapidly?"
  
  "Oh, really fast. Makes the whole thing shimmer."
  
  The springs on Kuroda's chair squeaked as he stood up. She heard him walking across the room and then walking back toward her, then repeating the process: pacing. "It can't be …" he said at last.
  
  "What?"
  
  He ignored her question. "How clearly could you see the individual cells?"
  
  She scratched Schrödinger behind the ears. "Cells?"
  
  "Pixels. I mean pixels. How clearly could you see them?"
  
  "It was really hard."
  
  "Can you try again? Can you put the eyePod in duplex mode now?"
  
  She fumbled to get the device out of her pocket without sending Schrödinger to the floor. Once it was free, she pressed the switch; the eyePod made its usual high-pitched beep, which Schrödinger answered with a surprised meow, and—
  
  And there it was, spreading out before her: the World Wide Web.
  
  "Can you see the background now?" Kuroda asked.
  
  "Yes, if I concentrate …"
  
  He sounded surprised. "You're squinting."
  
  She shrugged. "It helps. But, yeah, if I really try, I can focus on a small group—a few hundred squares on a side."
  
  "Okay. Do you have a Go board?"
  
  "What?"
  
  "Um, okay—do you have any money?"
  
  She narrowed her eyes again, but this time in suspicion. "Fifty bucks, maybe, but …"
  
  "No, no. Coins! Do you have coins?"
  
  "In a jar on my dresser." She was saving to go see Lee Amodeo with Bashira when she came to Centre in the Square.
  
  "Great, great. Do you mind if I go get it?"
  
  "I can do it. It's my house."
  
  "No, you take the time to look at the Web, see if you can make out any more detail in the background. I'll be right back."
  
  Kuroda could never sneak up on anyone. She heard the sounds of his return long before he actually arrived. She then heard a great jangling as he dumped the coins on their worktable, and more noise as he shuffled them around—perhaps sorting them. "All right. Here's a bunch of coins. Can you arrange them in the pattern you're seeing? Put one down for each light spot, and leave a coin-sized space for each dark spot."
  
  Caitlin shooed Schrödinger out of her lap and swung her chair to face the table. "I told you. They keep changing."
  
  "Yes, yes, but …" He made a noisy sigh. "I wish there were some way to photograph it, or at least to slow down your perception, and—" His voice brightened. "And there is! Of course there is!"
  
  She heard him moving about, then soft keyclicks. "What are you doing?" she asked.
  
  "I'm halting your reception of the datastream from Jagster, and just passing on the last iteration of it over and over again, so it'll keep coming down the pike without changing, sort of like—"
  
  "A freeze-frame!" she said as the image ceased to move. She was delighted to be able to apply another concept she'd only ever read about before.
  
  "Exactly. Now, can you make a pattern with the coins that matches what you're seeing in a portion of the background?"
  
  "A very small portion," she said. And she started moving the coins around; he'd given her a bunch of dimes. After a moment, she pushed one off to a corner of the desk. "American," she said; all those years of reading Braille made it easy to tell Queen Elizabeth from FDR.
  
  She built up a grid of dimes and dime-sized empty spaces, counting the coins automatically as she deployed them. "Done," she announced. "Eight dollars and ninety cents."
  
  "Completely random," Kuroda said, sounding disappointed.
  
  "No, it's not. Not quite. See this group of five dimes here?" She had no trouble keeping track of the pattern she'd made, and touched the appropriate coins. "It's the same as this group here, except turned ninety degrees to the right."
  
  "So it is," he said, excitedly. "It looks like the letter L."
  
  "And this one's the same, too," she said, "turned upside down."
  
  "Excellent!"
  
  "But what does it mean?" she asked.
  
  "I'm not a hundred-percent sure," he said. "Not yet. Here, focus your attention again on the same spot in your vision. I'm going to update the data going to your implant, just once … and done."
  
  "Okay. It's completely different."
  
  "Can you make it for me with the coins?"
  
  "I'm not even sure I'm looking at the same spot anymore," she said. "But here goes." She rearranged the dimes, and, just to underscore that not only the pattern but also the number of light and dark squares had changed, she added, "Six dollars and twenty cents." She paused. "Ah! Three sets of that five-coin pattern this time."
  
  "And in different places," he said.
  
  "But what does it mean?"
  
  "Well," said Kuroda, "this may sound crazy, but I think they're cellular automata."
  
  "Who in the what now?"
  
  "Hey, I thought you were the daughter of a physicist," he said, but his tone was one of gentle teasing.
  
  She smiled. "Sue me. And besides, if they're cellular, I'd need to be a biologist's daughter, no?"
  
  "No, no—they're not biological cells; they're cells in the computer-science sense of the word: a cell is the basic unit of storage in computer memory, holding a single unit of information."
  
  "Ah."
  
  "And an automaton is something that behaves or responds in a predictable, mechanical way. So cellular automata are patterns of information units that respond in a specific way to changes in their surroundings. For example, take a grid of black and white squares—each square is a cell, okay?"
  
  "Yes."
  
  "And on a chessboard that goes on forever, each square has eight neighbors, right?"
  
  "Right."
  
  "Well, suppose you say to each square something like, okay, if you're already black and three or more of your neighbors are white, then turn white yourself. An instruction like that is called a rule. And if you keep applying the rule over and over again, strange things happen. I mean, yes, if you just focus on one individual square, all you'd see is it flipping back and forth between black and white. But if you look at the overall grid, patterns of squares can seem to move across it—cross shapes, maybe, or hollow squares, or L shapes like we have here, or clusters of cells that change shape in set stages and, after a fixed number of steps, return to their original shape, but have moved somewhere else in the process. It's almost as though the shapes are alive."
  
  She heard the chair groan as he shifted in it.
  
  "I remember when I first encountered cellular automata in Conway's Game of Life as an undergrad," he said. "What's fascinating about all this is that they're representations of data that are interpreted as being special by an observer. I mean, those L-shaped things—they're called 'spaceships,' by the way, these patterns that retain their cohesion and fly across the grid—well, spaceships don't really exist; nothing is actually moving, and the spaceship you see on the right side of the grid is completely different in composition from the one you originally saw on the left side. And yet we think of it as the same one."
  
  "But what are they for?"
  
  "Besides making undergrads go 'ooooh,' you mean?"
  
  "Yeah."
  
  "Well, in nature—"
  
  "These occur in nature?"
  
  "Yes, in lots of places. For instance, there's a kind of snail that makes the pattern on its shell in direct response to a cellular-automata rule."
  
  "Really?"
  
  "Yes. It has a row of spigots that spit out pigment, or not, based on what the neighboring spigots on either side are doing."
  
  "Cool!"
  
  "Yes, it is. But what's really cool is that there are cellular automata in brains."
  
  "Really?" she said again.
  
  "Well, they're in lots of kinds of cells, actually. But they've been studied particularly in neural tissue. The cytoskeletons of cells—their internal scaffolding—is made up of long strings called microtubules, and each component of a microtubule, a little piece of protein called a tubulin dimer, can be in one of two states. And those states go through permutations as though they were cellular automata."
  
  "Why would they do that?"
  
  "No one knows. Some people, though, including—hey, maybe your father knows him? Roger Penrose? He's a famous physicist, too, and he and his associate, a guy named Hameroff, think that those cellular automata are the actual cause of consciousness, of selfawareness."
  
  "Sweet! But why?"
  
  "Well, Hameroff is an anesthesiologist, and he's shown that when people are put under for surgery their tubulin dimers fall into a neutral state—instead of some being black, say, and some being white, they all sort of become gray. When they do that, consciousness goes off; when they start behaving as cellular automata again, consciousness comes back on."
  
  She made a mental note to google this later. "But if the snail has spigots, and the brain has these whatchamacallits—"
  
  "Tubulin dimers," said Kuroda.
  
  "Okay, well if these tubulin dimers are the actual things that are flipping in the brain, what's flipping in the background of webspace?"
  
  She imagined him shrugging; it would have gone naturally with his tone of voice. "Bits, I guess. You know: binary digits. By definition, they're either on or off, or one or zero, or black or white, or however you want to visualize them. And maybe you're visualizing them as squares of two different colors, just at the limit of your mental resolution."
  
  "But, um, the Web is supposed to pass on data unchanged," she said. "A browser asks for a Web page, and an exact copy of it is sent from the server that hosts that page. There shouldn't be any data changing."
  
  "No," he said. "That's puzzling."
  
  They sat in silence for a few moments, contemplating this. And then she heard her mother's distinctive footsteps on the stairs, followed by her saying, "Hey, you two, anyone care for a mid-morning snack?"
  
  Kuroda's chair squeaked again as he heaved his bulk up from it. "I always think better on a full stomach."
  
  You must do a lot of thinking, Caitlin thought, and she smiled as they went upstairs.