Calculating God

by Robert J. Sawyer

  “Can I go watch TV until it’s time for dinner?” Ricky asked.

  We normally let Ricky watch only one hour of TV a night, and he’d already done that. But I couldn’t disappoint him again. “Sure,” I said.

  Ricky got up. I let out a heavy sigh.

  He’d said we were friends.

  Ah, well. I stood up, picked up the projector, weighed it in my hand, then put it back in my briefcase, and—

  A sound, from the back door. I closed my briefcase and headed off to investigate. Our back door opened onto a wooden deck that my brother-in-law Tad and I had built five summers ago. I opened the vertical blinds over the sliding glass door, and—

  It was Hollus, standing on my deck.

  I removed the security rod along the base of the glass door and slid the door open. “Hollus!” I said.

  Susan had appeared behind me, wondering what I was up to. I turned to look at her; she’d seen Hollus and other Forhilnors often enough on TV, but her mouth was now agape.

  “Come in,” I said. “Come in.”

  Hollus managed to squeeze through the doorway, although it was a tight fit. He had changed for dinner; he was now wearing a wine-colored cloth, fastened with a polished slice out of a geode. “Why didn’t you appear inside?” I asked. “Why project yourself outside?”

  Hollus’s eyestalks moved. There was something subtly different about the way he looked. Maybe it was just the lighting, from a halogen torchiere lamp; I was used to seeing him under the fluorescent panels we have at the museum.

  “You invited me to your home,” he said.

  “Yes, but—”

  Suddenly, I felt his hand upon my arm. I’d touched him before, felt the static tingle of the force fields that composed his projection. This was different. His flesh was solid, warm.

  “So I came,” he said. “But—I am sorry; I have been out there for a quarter of an hour, trying to figure out how to let you know that I had arrived. I had heard of doorbells, but could not find the button.”

  “There isn’t one at the back door,” I said. My eyes were wide. “You’re here. In the flesh.”

  “Yes.”

  “But—” I peered behind him. There was something large in the backyard; I couldn’t quite make out its form in the gathering darkness.

  “I have been studying your planet for a year,” Hollus said. “Surely you must have suspected we had ways to reach your planet’s surface without attracting undo attention.” He paused. “You invited me for dinner, did you not? I cannot enjoy your food via telepresence.”

  I was amazed, thrilled. I turned to look at Susan, then realized I’d forgotten to introduce her. “Hollus, I’d like you to meet my wife, Susan Jericho.”

  “Hell,” “oh,” said the Forhilnor.

  Susan was quiet for a few seconds, stunned. Then she said, “Hello.”

  “Thank you for allowing me to visit your home,” Hollus said.

  Susan smiled, then looked rather pointedly at me. “If I’d had more advance notice, I could have cleaned the place up.”

  “It is lovely as is,” said Hollus. His eyestalks swiveled, taking in the room. “Great care has obviously gone into the selection of each piece of furniture so that it complements the others.” Susan normally couldn’t stand spiders, but the big guy was clearly charming the pants off her.

  In the bright light of the torchiere, I noticed tiny studs, like little diamonds, set into his bubble-wrap skin at each of the two joints in his limbs, and the three joints in his fingers. And a full row of them ran along each of his eyestalks. “Is that jewelry?” I said. “If I knew you were interested in such things, I’d have shown you the gem collections at the ROM. We’ve got some fabulous diamonds, rubies, and opals.”

  “What?” said Hollus. And then, realizing, his eyestalks did their S-ripple again. “No, no, no. The crystals are the implants for the virtual-reality interface; they are what allow the telepresence simulacrum to mimic my moves.”

  “Oh,” I said. I turned around and shouted out Ricky’s name. My son came bounding up the stairs from the basement. He started to head to the dining room, thinking I’d called him for dinner. But then he caught sight of me and Susan and Hollus. His eyes went wider than I’d ever seen them. He came over to me, and I put an arm around his shoulders.

  “Hollus,” I said, “I’d like you to meet my son Rick.”

  “Hell” “oh,” said Hollus.

  I looked down at my boy. “Ricky, what do you say?”

  Ricky’s eyes were still wide as he looked at the alien. “Cool!”

  We hadn’t expected Hollus to show up for dinner in the flesh. Our dining-room table was a long rectangle, with a removable leaf in the middle. The table itself was dark wood, but it was covered with a white tablecloth. There really wasn’t much room for the Forhilnor. I had Susan help me move the sideboard out of the way to free up some space.

  I realized I’d never seen Hollus sit down; his avatar obviously didn’t need to, but I thought the real Hollus might be more comfortable if he had some support. “Is there anything I can do to make you more comfortable?” I asked.

  Hollus looked around. He spotted the ottoman in the living room, positioned in front of the love seat. “Could I use that?” he said. “The little stool?”

  “Sure.”

  Hollus moved into the living room. With a six-year-old boy around, we didn’t have any breakables out, which was a good thing. Hollus bumped the coffee table and the couch on his way; our furniture wasn’t spread out enough for a being of his proportions. He brought back the ottoman, placed it by the table, then stepped over it, so that his round torso was directly above the circular stool. He then lowered his torso down onto it. “There,” he said, sounding content.

  Susan looked quite uncomfortable. “I’m sorry, Hollus. I didn’t think you were actually, really coming. I have no idea whether what I made is something you can eat.”

  “What did you make?”

  “A salad—lettuce, cherry tomatoes, diced celery, bits of carrot, croutons, and an oil-and-vinegar dressing.”

  “I can eat that.”

  “And lamb chops.”

  “They are cooked?”

  Susan smiled. “Yes.”

  “I can eat that, too, if you can provide me with about a liter of room-temperature water to go with it.”

  “Certainly,” she said.

  “I’ll get it,” I said. I went to the kitchen and filled a pitcher with tap water.

  “I’ve also made milk shakes for Tom and Ricky.”

  “This is the bovine mammary secretion?” asked Hollus.

  “Yes.”

  “If it is not rude to do so, I will not partake.”

  I smiled, and Ricky, Susan, and I took our places at the table. Susan brought the salad bowl out and passed it to me. I used the serving forks to move some to my plate, then loaded some onto Ricky’s. I then put some on Hollus’s plate.

  “I have brought my own utensils,” he said. “I hope that is not rude.”

  “Not at all,” I said. Even after my trips to China, I was still one of those who always had to ask for a knife and fork in a Chinese restaurant. Hollus pulled two devices that looked a bit like corkscrews from the folds of the cloth wrapped around his torso.

  “Do you say grace?” asked Hollus.

  The question startled me. “Not normally.”

  “I have seen it on television.”

  “Some families do it,” I said. Those that have things to be thankful for.

  Hollus used one of his corkscrews to stab some lettuce, and he conveyed it to the orifice on top of his circular body. I’d watched him make the motions of eating before, but had never seen him actually do it. It was a noisy process; his dentition made a snapping sound as it worked. I suppose only his speaking orifices were miked when he used his avatar; I presumed that was why I’d never heard the sound before.

  “Is the salad okay?” I asked him.

  Hollus continued to transfer it into his
eating orifice while he spoke; I guessed that Forhilnors never choked to death while dining. “It is fine, thank you,” he said.

  Ricky spoke up. “Why do you talk like that?” he asked. My son imitated Hollus by speaking in turns out of the left and right sides of his mouth. “It” “is” “fine” “thank” “you.”

  “Ricky!” said Susan, embarrassed that our son had forgotten his manners.

  But Hollus didn’t seem to mind the question. “One thing that humans and my people share is a divided brain,” he said. “You have a left and right hemisphere, and so do we. We hold that consciousness is the result of the interplay of the two hemispheres; I believe humans have some similar theories. In cases where the hemispheres have been severed due to injury, so that they function independently, whole sentences come out of a single speaking orifice, but much less complex thoughts are expressed.”

  “Oh,” said Ricky, going back to his salad.

  “That’s fascinating,” I said. Coordinating speech between partially autonomous brain halves must be difficult; maybe that was why Hollus was apparently incapable of using contractions. “I wonder if we had two mouths, whether humans would alternate words or syllables between them as well.”

  “You seem to rely less on left-right integration than we Forhilnors do,” Hollus said. “I understand that in cases of a severed corpus callosum, humans can still walk.”

  “I think that’s right, yes.”

  “We cannot,” Hollus said. “Each half of the brain controls three legs, on the corresponding side of the body. All our legs have to work together, or we topple over, and—”

  “My daddy is going to die,” said Ricky, looking down at his salad plate.

  My heart jumped. Susan looked shocked.

  Hollus put down his eating utensils. “Yes, he told me. I am very sorry about that.”

  “Can you help him?” asked Ricky, looking now at the alien.

  “I am sorry,” said Hollus. “There is nothing I can do.”

  “But you’re from space and stuff,” said Ricky.

  Hollus’s eyestalks stopped moving. “Yes, I am.”

  “So you should know things.”

  “I know some things,” he said. “But I do not know how to cure cancer. My own mother died from it.”

  Ricky regarded the alien with great interest. He looked like he wanted to offer a word of comfort to the alien, but he clearly had no idea what to say.

  Susan stood up and brought the lamb chops and mint jelly in from the kitchen.

  We ate in silence.

  I realized that an opportunity had presented itself that wasn’t likely to be repeated.

  Hollus was here in the flesh.

  After dinner, I asked him down to the den. He had some trouble negotiating the half-flight of stairs, but he managed.

  I went to a two-drawer filing cabinet and pulled out a sheaf of papers. “It’s normal for people to write a document called a will to indicate how one’s personal effects should be distributed after death,” I said. “Naturally, I’m leaving almost everything to Susan and Ricky, although I’m also making some bequests to charities: the Canadian Cancer Society, the ROM, a couple of others. There are also a few things going to my brother, his children, and one or two other relatives.” I paused. “I—I’ve been thinking of amending my will to leave something to you, Hollus, but well, it seemed pointless. I mean, you won’t likely be around after I’m gone, and, well, usually you’re not really here, anyway. But tonight…”

  “Tonight,” agreed Hollus, “it is the real me.”

  I held out the sheaf of papers. “It’s probably simplest if I just give you this now. It’s the typescript for my book Canadian Dinosaurs. These days, people write books on computers, but that one was banged out on a manual typewriter. It doesn’t have any real value, and the information is now very much out of date, but it’s my little contribution to the popular literature about dinosaurs, and, well, I’d like you to have it—one paleontologist to another.” I shrugged a little. “Something to remember me by.”

  The alien took the papers. His eyestalks weaved in and out. “Your family will not want this?”

  “They have copies of the finished book.”

  He unwrapped a portion of the cloth around his torso, revealing a large plastic carrying pouch. The manuscript pages fit in with room to spare. “Thank you,” he said.

  There was silence between us. At last, I said, “No, Hollus—thank you. For everything.” And I reached out and touched the alien’s arm.

  * * *

  17

  I

  sat in our living room, late that night, after Hollus had returned to his starship. I’d taken two pain pills, and I was letting them settle before I went to bed—the nausea sometimes made it hard to keep the pills down.

  Maybe, I thought, the Forhilnor was right. Maybe there was no smoking gun that I would accept. He said it was all there, right in front of my eyes.

  There are none so blind as those who will not see; besides the Twenty-ninth Scroll, that’s one of my favorite bits of religious writing.

  But I wasn’t blind, dammit. I had a critical eye, a skeptic’s eye, the eye of a scientist.

  It stunned me that life on assorted worlds all used the same genetic code. Of course, Fred Hoyle had suggested that Earth—and presumably other planets—were seeded with bacterial life that drifted in from space; if all the worlds Hollus had visited were seeded from the same source, the genetic code would, of course, be the same.

  But even if Hoyle’s theory isn’t true—and it’s really not a very satisfying theory, since it simply pushes the origin of life off to some other locale that we can’t easily examine—maybe there were good reasons why only those twenty amino acids were suitable for life.

  As Hollus and I had discussed before, DNA has four letters in its alphabet: A, C, G, and T, for adenine, cytosine, guanine, and thymine, the bases that form the rungs of its spiral ladder.

  Okay—a four-letter alphabet. But how long are the words in the genetic language? Well, the purpose of that language is to specify sequences of amino acids, the building blocks of proteins, and, as I said, there are twenty different aminos used by life. Obviously, you can’t uniquely identify each of those twenty with words just one letter long: a four-letter alphabet only provides four different one-letter words. And you couldn’t do it with words two letters long: there are only sixteen possible two-letter words in a language that has just four characters. But if you use three-letter words, ah, then you’ve got an embarrassment of riches, a William F. Buckley-style biochem vocabulary of a whopping sixty-four words. Set aside twenty to name each amino acid, and two more for punctuation marks—one for starting transcription and another for stopping. That means only twenty-two of the sixty-four possible words are needed for DNA to do its work. If a god had designed the genetic code, he must have looked at the surplus vocabulary and wondered what to do with it.

  It seems to me that such a being would have considered two possibilities. One was to leave the remaining forty-two sequences undefined, just as there are letter sequences in real languages that don’t form valid words. That way, if one of those sequences cropped up in a string of DNA, you’d know that a mistake had occurred in copying—a genetic typo, turning the valid code A-T-A into, say, the gibberish A-T-C. That would be a clear, useful signal that something had gone wrong.

  The other alternative would be to live with the fact that copying errors were going to occur, but try to reduce their impact by adding synonyms to the genetic language. Instead of having one word for each amino acid, you could have three words that mean the same thing. That would use up sixty of the possible words; you could then have two words that mean start and two more that mean stop, rounding out the DNA dictionary. If you tried to group the synonyms logically, you could help guard against transcription errors: if A-G-A, A-G-C, and A-G-G all meant the same thing, and you could only clearly read the first two letters, you’d still have a good shot at guessing what the wor
d meant even without knowing the third letter.

  In fact, DNA does use synonyms. And if there were three synonyms to specify each amino acid, one might look at the code and say, yup, someone had carefully thought this out. But two amino acids—leucine and serine—are specified by six synonyms each, and others by four, three, two, or even just one: poor tryptophan is specified only by the word T-G-G.

  Meanwhile, the code A-T-G can mean either the amino acid methionine (and there are no other genetic words for it) or, depending on context, it can be the punctuation mark for “start transcription” (which also has no other synonyms). Why on Earth—or anyplace else—would an intelligent designer make such a hodgepodge? Why require context sensitivity to determine meaning when there were enough words available to avoid having to do that?

  And what about the variations in the genetic code? As I’d told Hollus, the code used by mitochondrial DNA differs slightly from that used by the DNA in the nucleus.

  Well, in 1982, Lynn Margulis had suggested that mitochondria—cellular organelles responsible for energy production—had started out as separate bacterial forms, living in symbiosis with the ancestors of our cells, and that eventually these separate forms were co-opted into our cells, becoming part of them. Maybe…God, it was a long time since I’d done any serious biochemistry…but maybe the mitochondrial and nuclear genetic codes had indeed originally been identical, but, when the symbiosis began, evolution favored mutations that allowed for a few changes in the mitochondrial genetic code; with two sets of DNA existing within the same cell, maybe these few changes served as a way to distinguish the two forms, preventing accidental mingling.

  I hadn’t mentioned it to Hollus, but there were also some minor differences in the genetic code employed by ciliated protozoans—if I remember correctly, three codons have different meanings for them. But…I was blue-skying; I knew that…but some said that cilia, those irreducibly complex organelles whose death had brought about my own lung cancer, had started out as discrete organisms, as well. Maybe those ciliated protozoa that had a variant genetic code were descended from some cilia who had been in symbiosis with other cells in the past, developing genetic-code variations for the same safety-net reasons mitochondria had but, unlike the cilia we still retained, had subsequently broken off the symbiosis and returned to stand-alone life.