Baker held the phone receiver up before him. “Answering machine,” he said and placed it back on its cradle.
“Can't help you then,” Tony said. “Want some juice?"
“Did anyone you know socialize with Ms. Theonsky?” Baker asked.
Tony's brow furrowed. “Nah, she keeps to herself, mostly. I mean, she likes to talk to the college kids sometimes, especially the ones who bring books to read in here.” He rubbed his temple. “Wait a minute! There was a time once—some kids got fresh with her—that was a couple of weeks ago, I guess. Stash walked her home. Hey, Stash!"
The white-haired old-timer looked up. “What?"
“'You know where Hypatia lives?"
“He said Thompson Street,” I was reminding Baker.
“Quite right, Woodside. But West Broadway will take us to West 3rd Street, where the New York University Student Center is housed. I suspect that Ms. Theonsky would choose a location near some academic environment. We can double back along Thompson."
We found the address at a row of brick walk-ups. There was, of course, no response at the bell, at which occasion Baker reached into one of the pockets of his Nehru coat and extracted a velvet-lined case of lock picks.
I glanced furtively about the darkened street, nearly toppling the afro once again. “Baker, are you aware...?"
“Hush, Woodside. Ms. Theonsky may be in some sort of danger. Under the circumstances, a surreptitious examination of her quarters may reveal a clue to her location.” His delicate long fingers had selected a thin rod and inserted it in the door-lock. “Certainly a bit of breaking and entering is justified at this juncture.” And with that the lock clicked open under his hands.
With a glance at the street Baker tried the doorknob. “No double-bolt, no alarm,” he said. “I thought as much.” Then, swinging the door open, he found the light switch and we entered hurriedly. The first floor seemed to be a kitchen/living room area, but there was a flight of stairs covered in dark, threadbare carpeting. Baker glanced about briefly, but headed quickly for the staircase, and I followed dutifully. At the landing there was a closet-sized bathroom with worn fixtures, and at the top of the stairs was a large bedroom littered with a miscellany of strange and familiar objects.
Several recent issues of Science and Nature were scattered on the floor, accompanied by a distinctly mole-like stuffed toy outfitted in a miniature lab coat with the words: “The Year of the Mole” and “6.02253 X 1023” emblazoned on it.
The bed was large and unmade and faced a computer monitor across the room that was endlessly scrolling an undulating horizontal message that read: “Live long and prosper!” There was a grease-stained empty pizza box on the nightstand, along with a nearly empty plastic bottle of spring water. A rectangular aquarium tank was set on a small table with an apparently contented fancy-tailed goldfish swimming sedately back and forth above a porcelain diver whose helmet was emitting a train of bubbles.
A chest of drawers stood against one wall, a mirrored dresser against another. Both showed several half-opened drawers with clothing contents overhanging the edges like vines from a planter. To my unpracticed eye it seemed as if the room had been hurriedly searched. I noticed my own image with the afro wig askew in the dresser mirror. In one corner of the wooden frame a sticker had been affixed: “Bad Hair Day."
“It appears that someone has gotten here before us,” Baker said, “although I see no signs of a struggle."
I surveyed the clutter and rummaged a bit in one of the drawers. Several expensive-looking jewelry items and some loose currency seemed to eliminate a simple robbery.
Baker had walked over to the computer and tapped the space bar. The screen saver message was replaced by what appeared to be an Excel spreadsheet full of numbers. I was walking over to examine the screen more closely when I inadvertently kicked an old VHS copy of the movie, Bob and Carol and Ted and Alice, which lay on the carpet at the foot of the bed. Baker had been scrolling the spreadsheet with the mouse and had just reached the last entry when I arrived holding the video.
“Very appropriate, Woodside,” Baker said, glancing at the title.
“Whatever do you mean, Baker?” I hardly thought that the 1960s comedy about bed-hopping couples bore upon the case.
“The names have traditionally been used in discussions about public key cryptography,” he said. “And they have been adopted workers in the much more nascent field of quantum cryptography. Bob and Alice, say, want to send secret messages to each other, so that they can't be intercepted by Ted and Carol. Bob sends Alice one of two quantumly entangled particles and stores the other. Alice then alters her particle in some way and sends it back to Bob, who measures the two particles together and can thus determine what change Alice made to the particle he sent her—and, thus, which of several messages she wants to send."
I found myself frowning at that. “If I understand quantum entanglement, doesn't that mean that Bob and Alice's particles always have to be in the same state no matter where they are?"
“Indeed, Woodside, if they are quantumly entangled they could be in different galaxies and yet must be in the same state."
“Then why must Alice send Bob her altered particle? Why must Bob measure both particles?"
Baker looked up from the screen, grinning. “Ah, but Woodside, you forget the Uncertainty Principle. If Bob could measure his lone particle, he would violate it. Of course, the approach I described has not yet been proven practicable, unless Alexander's work has led to new discoveries. The potential is there, however, to effectively double the capacity of a secure information channel."
I nodded as if it all made sense, which I had always found the most efficacious tactic in any discussion of quantum mechanics. I glanced at the computer screen. “Can you make any sense of those columns of numbers?” I asked.
Baker was still scrolling with the mouse. “Not with any certainty, although several of these progressions are suggestive. Unfortunately, Ms. Theonsky's columns are labeled only with default alphabetic codes."
“Do you think it has to do with quantum computing?"
“Possibly. You know, of course, Woodside, that quanta can be superimposed."
I searched my memory. “Two states at the same time?"
“Precisely. For example, a ‘qubit,’ that is, a quantum bit in a hypothetical quantum computer, could exist in the 0 and 1 states simultaneously until it was measured. At which event it would ‘collapse’ into one state.” Baker looked up at me from the screen. “If one has a two-qubit word—"
“A qubyte?"
“Perhaps. At any rate, two qubits have four simultaneous values, again assuming binary logic—that is—” And he pulled out a pad and pen and jotted: (00), (01), (10), and (11). “A three-qubit word would have eight simultaneous values, a four-qubit word sixteen, and so on. The point is, of course, that the computer's machine cycles—its logical operations—will operate on all these values at the same instant in the same register. The potential calculating power becomes staggering when one considers that just 100 qubits represent 2100, which is 1030, distinct words. The potential is there to factor large numbers that are far beyond the practical power of conventional computing."
I'd reached a point where I felt the need to sound at least a little knowledgeable. “And factoring large numbers is the underlying basis of the best encryption systems,” I offered.
“Exactly, Woodside. Something called RSA—an acronym for the last names of its three inventors—has become fairly standard. It is undoubtedly for this reason that the government is funding Alexander's efforts in order to control this technology. A hacker with a working quantum computer could easily eavesdrop on the most currently secure transmissions."
I scratched at my forehead. “Alexander led us to believe that Hypatia Theonsky was engaged in a minor, nearly irrelevant, aspect of the project—error correction, wasn't it?"
Baker looked up again from the computer. “That was a rather obvious prevarication, Woodside. Quantum
error correction is, in fact, the key element in the development of a working system. ‘Decoherence’ is the term used. It refers to the loss of information due to interaction with the environment. The slightest perturbation—an errant photon, an atomic vibration—can instantly collapse the system and garble the output."
I sensed a Baker-style lecture coming on and sat down on the edge of the bed with an audible twang of its springs.
“Redundancy and frequent checks for altered bits is one approach, borrowed from conventional computing. There are also ways to use feedback loops based on anticipated errors that restore the system to a decoherence-free initial state. Everything, of course, depends on what physical system the quantum computer is based upon. Such a machine could be based on nuclear spin with readout by magnetic resonance techniques. In such a design a minuscule volume of organic liquid might serve the function of millions of computer memory registers. An analogous approach would utilize electron spin and read-out by electron paramagnetic resonance. An ion trap would work as well.
“The point is, Woodside, that the essential working quantum computer would interact weakly with its environment but strongly with itself. I believe the cloak of secrecy around Alexander's project may possibly involve quantum dots—small groups of atoms with an excess of one electron. The spin of that electron—up or down—would represent the two logic states of one qubit."
“And what of Hypatia?” I said.
“Quite so. Her immediate whereabouts must be our greatest concern.” Baker inserted a diskette into the computer and copied the Excel file.
We were back at Baker's quarters. I was making coffee to stave off exhaustion and Baker was at his PC still studying the file from Hypatia's computer.
“There is something here, Woodside. But if you would use some of that excess energy to make me a pot of Earl Grey, I should be most grateful."
And so I dutifully served Baker his tea.
He was just raising his cup when I saw his eyes widen at the glowing screen.
“It's as clear as day, by George!” he said, nearly spilling his beverage.
I came over and squinted at the columns of numbers, whose meaning remained impenetrable to me.
“Don't you see it, Woodside?” Baker looked up at me. “No, of course you don't.” I winced a bit at that, but as usual, managed to contain my chagrin.
“This first column represents the qubit register—an eight-bit byte, as it were. Note that its value remains unchanged in the subsequent 256 rows. The adjoining column lists the 256 possible states for that ‘word.’ The next column lists the real and imaginary coefficients that correspond to the amplitude of each of those 256 states.” Baker pointed to the screen. “Woodside, this appears to be a mock-up of the output of a working quantum computer."
“I'm afraid I don't quite..."
“The amplitude—actually the sums of the squares of these two coefficients in the third column, which appear in the fourth column—is the quantum probability that a given state of a register is the true value. At the beginning of a run, these values would all be the same: all equally probable. At the conclusion of the program execution the register states with the highest probability represent the output."
“Why did you call this a ‘mock-up’ Baker? Couldn't it be an actual output from a quantum computer?"
Baker shook his head with that look that had always made me feel like a particularly dull schoolboy. “No, Woodside, these registers could never be seen in a real quantum computing device. When the program had finished its operations—matrix multiplication, or whatever—it would, indeed, have returned such a set of numbers. But the act of measurement—the read-out in this case—would have returned only the true or highest probability value and have destroyed all other values. The Heisenberg Clause again, as it were."
As I looked at the long lists of numbers, a question occurred to me. “Back in the ‘60s when computing was still pretty primitive, wasn't there—"
Baker visibly brightened. “You may have hit upon it, Woodside! Before hexadecimal and 32-bit words, there was octal. The technical difficulties of quantum computing severely restrain word size. Before one can run, one must crawl."
“Do you think that Hypatia Theonsky left an octal coded message?"
Baker nodded. “It is an excellent conjecture. We just select the highest probability output from each of 256 rows for each octal bit. Ms. Theonsky must have known that she was being watched and chose this means to leave a clue to the mystery. Be a good chap, Woodside, and grab a paper and pen to jot this down as I scroll through this spreadsheet."
I watched it evolve and I recorded it as Baker scrolled, calling off the eight-bit string that represented the highest probability for each register. It took rather longer than I imagined. My coffee had grown cold, but I sipped at it when we had finally finished and I handed Baker the list of digits.
Baker pounced upon the paper and dug some reference texts out of a desk drawer. “Woodside,” he said, flipping through dog-eared pages, “don't you miss those machine language days when it took 20 programming steps to add two numbers?"
At first I thought he was joking, but the unrestrained and uncharacteristic glee on his face suggested that he was not.
“Here it is, old fellow. They are, in fact, alphabetic characters in hexadecimal code.” And he began to write letters down the page after each 16 binary digits: “G-O-L—"
“Of course,” he said. “How could I have overlooked it?"
“-D-F-I-S-H"
I drained my cup. It was going to be a long night. “The goldfish in Hypatia's apartment?"
“We must return at once.” Baker was already up and moving.
“Can we dispense with the costumes?” I suggested.
“The time for subterfuge is past, Woodside. Hypatia Theonsky took some pains to conceal this message, and I believe that unfriendly forces may have a copy of this spreadsheet. We must move with alacrity."
This time we took the Volkswagen and, despite a series of aggressive bumper nudges from Manhattan cabbies, we made it to Greenwich Village. When we arrived at Hypatia's apartment the front door was slightly ajar, despite the fact that Baker had carefully closed and relocked it upon our recent departure. “An ominous sign, Woodside,” he said, as we pushed in and mounted the stairs.
The apartment's bedroom was once again devoid of occupants and appeared just as we had left it, except—Baker was standing next to the aquarium, where the helmeted diver continued to stream bubbles. There was water on the sides of the tank and a small puddle on the table. And, of course, the goldfish was gone.
“Baker, what do the goldfish have to do with all of this?” I had been holding back the question, trying to figure it out on my own, but had failed completely.
“The DNA non-coding segment cryptography, of course, Woodside. An elaboration of young Randal's project, but inserted into living DNA. The goldfish, undoubtedly, was the subject of such an experiment."
“But what could be the message?"
“A key to something vital, I would surmise. And now, someone has that information."
“What do we do now?” I asked.
“In the absence of useful data we play the odds, Woodside. We disturb the rest of Professor Synesius."
“A goldfish? Oh, yes, I suppose it's just possible with some of the techniques that Hypatia developed. But why would anyone want to leave a message embedded in the DNA of a living animal?” Dr. Synesius was in a bathrobe and wearing a shower cap.
“As a subtle form of concealment, doctor. We have a strong suspicion that Hypatia is in danger."
“My God! Really? Where is she? I'll get dressed at once.” Dr. Synesius appeared quite upset.
Baker attempted to calm him. “We don't know her whereabouts, doctor. However, I suspect that whoever removed the goldfish from Ms. Theonsky's apartment will need the facilities in your laboratory to decode the message. If you will gain access for us, we can investigate."
“Of course, just g
ive me a minute.” And with that the little man disappeared up the stairs to re-emerge a few moments later in street clothes. “I'd better drive us. Campus Security knows my car."
Baker hesitated but agreed and we piled into the plush luxury of a late model Lincoln Town Car.
“I can't believe that anyone would want to harm Hypatia,” Synesius said, as we backed out of the driveway, carefully avoiding Baker's parked antiquity.
Baker remained silent until we neared the Ptolard campus. “How much do you know about Cyril Alexander, doctor?” he said at last.
“Cyril? A bit uptight, perhaps. I haven't a lot of dealings with him, except for those personnel transfers. He's always draining away our best programmers.” Synesius changed his tone. “You're not suggesting that he is somehow involved in Hypatia's plight?"
The dark trees of the campus streamed by the car windows, the winding footpaths now deserted. Baker allowed the soft sound of the engine to fill the delay in his response.
“I have conjectured that Ms. Theonsky played a much larger role in the quantum computer project than Dr. Alexander was willing to admit to us—that, in fact, she holds the key element in decoherence correction. The success of the project may hinge upon some software coding that she developed."
Synesius braked at a red light, his fingers drumming nervously on the steering wheel. “And you believe all this code has been embedded in the DNA of her pet goldfish? I hardly think—"
“No, doctor, but, perhaps a location cipher—something like a locker number or a safe combination for some cache where a disk or hardcopy of the software resides."
Synesius knitted his brows as the light changed and we pulled out. “Do you think Hypatia herself has been abducted?"
Analog SFF, November 2005 Page 18