Analog SFF, July-August 2008
Page 24
One “side effect” of such hidden dimensions is the possibility of shadow matter (sometimes called mirror matter), an additional type of matter that would interact normally with its own matter-type but would “ignore” ordinary matter, interacting with it only through the gravitational interaction. Thus, in a sense, such extra “hidden” dimensions may allow the existence of parallel universes to which one can “teleport.” Changing normal matter to shadow matter looks like teleportation between parallel universes. My own hard SF novel Twistor used this concept as a premise. Apparatus in a University of Washington experimental physics laboratory unexpectedly rotated normal matter into shadow matter and vice versa, causing objects and people to disappear and to be transported to an Earthlike shadow world. Therefore, extra dimensions are one physics-based way of accomplishing teleportation.
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Quantum Teleportation
Quantum teleportation, which has received a lot of discussion by science writers lately, is not about making a quantum jump to another location. Instead, it is a quantum mechanically valid solution to the problem of how to make a precise duplicate copy of a quantum state at another location. According to the rules of quantum mechanics, you cannot just measure a quantum system and use the measurement results to reconstruct the system somewhere else, because (a) the act of measurement changes the system measured, and (b) the uncertainty principle prevents simultaneous measurement of “conjugate quantities” like position and momentum that would be needed for such reconstruction. Another quantum rule prevents you from “cloning” multiple copies of a quantum system, so any duplication requires destruction of the original.
The procedure for quantum teleportation requires the following steps: (a) Create a pair of “blank” quantum systems that are “entangled,” i.e., separated but linked through some conservation law; (b) mix the “teleportee” with one of these entangled states and make a number of measurements on the mixed system; (c) transmit the measurement results by a normal communication channel to the location of the entangled twin system; and (d) perform a set of transformations on the entangled twin system based on the received measurement results. If this procedure is carried out correctly, you should have produced an exact duplicate of the original quantum state in the new location. Note that the mixing and measuring have destroyed the original system.
Essentially, one is using Nature's private entanglement channel to send most of the information needed to reproduce the original system. The number of measurements needed for such teleportation is the logarithm of the degree of system complexity, which keeps the needed number of measurements fairly small. For example, to teleport a quantum system consisting of 10,000 moles of atoms (about the equivalent of one person) to an identical state somewhere else, you would need to do only about 195 measurements on the mixed system.
I should emphasize that unlike extra-dimensional and wormhole physics, quantum teleportation is not conjecture but real physics. It has been demonstrated in many laboratories, with apparatus that actually teleports single particles and photons. Moreover, in 2006 Eugene Polzik and his team at Denmark's Niels Bohr Institute reported teleporting a very complex atomic system containing about 1012 atoms to a location half a meter away.
So how would you actually quantum-teleport people (a la Star Trek transporter)? I'm not sure. The problem, on the human level, is what to use for the pair of entangled blank quantum systems, on which the characteristics of the teleported person must be imposed. You'd need an entangled pair of “blank human beings” (perhaps clones of Mitt Romney?). Then maybe you'd get a huge blender, put in the subject and one blank, mix the states, make 195 or so measurements on the mixture, transmit the results, and the transform the other blank 195 times, until the teleported person pops out. But I don't think I'd volunteer to be the first test subject. There are some engineering details here than need to be worked out.
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Wormhole Teleportation
This brings us to wormhole teleportation, which is the premise of Jumper. In 1935 Albert Einstein and his colleague Nathan Rosen discovered that the formalism of general relativity (our current standard model for gravity) has solutions involving “teacup handle” curved space objects that could connect one region of space-time to a completely separate region. They suggested that fundamental particles (electrons, protons, etc.) might actually be such objects, with lines of electric flux threaded through them to give them electric charges. At the time, these objects were called “Einstein-Rosen Bridges,” but they are now called “wormholes.” (My hard SF novel, Einstein's Bridge, derives its title from this antique name for wormholes.)
In 1962, Wheeler and Fuller showed that such wormholes were much too massive to be fundamental particles, and that they were so unstable that if one happened to pop out of the vacuum, it would close up before even a single photon could be shot through it. However, in 1988, Kip Thorne and his student Mike Morris showed that wormholes could be stabilized and that, using relativistic time dilation, they could be converted into time machines, “time holes” that connect one time to another in the same place. (See several of my AV columns on wormholes for the details of this process.)
The two mouths of Thorne-Morris wormholes are subject to a phenomenon called “back reaction,” a manifestation of conservation laws. If an object of mass m passes through, the entrance mouth must gain its mass-energy (E=mc2) and the exit mouth must lose the same energy. The same is true of other conserved quantities: momentum, angular momentum, and electric charge. Perhaps the best solution to this problem would be so send some “ballast object” with the same mass, etc., simultaneously through the wormhole in the opposite direction.
The Jumper film suggests that the human teleporters are creating a wormhole and passing through it to another location without anything going in the opposite direction. Back reaction would seem to create great problems for this scenario, because, unless the mass-energy at the wormhole entrance was somehow contained, the wormhole mouth would explode like an H-bomb. There were also some violations of momentum back reaction involving the teleportation of a fast moving car and a double-decker bus.
However, despite these physics problems I found that Jumper was an enjoyable film, and I did not find that my suspension of disbelief was stretched to the breaking point. It was fun.
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AV Columns Online: Electronic reprints of about 140 “The Alternate View” columns by John G. Cramer, previously published in Analog, are available online at: www.npl.washington.edu/av.
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References:
Quantum Teleportation:
C. H. Bennett, G. Brassard, C. Crepeau, R. Jozsa, A. Peres, and W. K Wootters, Phys. Rev. Letters 70, 1895 (1993).
Wormholes & Time Machines:
Michael S. Morris, Kip S. Thorne, and Ulvi Yurtsever, Physical Review Letters 61, 1446 (1988).
Copyright (c) 2008 John G. Cramer
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* * *
Probability Zero: OUTSIDE THE BOX
by Jerry Oltion
When two armed policemen came out through the airlock to haul him back inside the habitat, Todd wasn't overly surprised. He had stolen the pressure suit, after all. He hadn't expected to be caught quite so quickly, but he had known it would eventually happen.
With eyes still blinking from the intense sunlight, he took one last look at the lunar landscape. Near the underground habitat's entrance the dull gray dirt had been churned by the wheels of countless construction vehicles, and farther out the solar collectors made stark black silhouettes, but beyond those he could see the softly rounded pockmarks of old craters in soil that had lain undisturbed for millennia. He could have seen the same thing—had seen the same thing many times—through remote cameras, but standing outside with only a bubble helmet between him and the actual surface made it much more immediate. Much more real.
He switched on his radio. His helmet immediately filled with a babble of voices that stilled when
he said, “All right, all right, I'm coming.” He turned away and trudged back to the airlock, his footsteps far heavier than the stolen suit's weight could account for. His grand exploration of the great outdoors had lasted less than fifteen minutes. He would probably get probation and have his RFID branded juvie until he turned 18, all for that.
“It was worth it,” he told the cops.
“I doubt that,” one of them replied. “You're in serious trouble.”
“For borrowing a spacesuit?” Todd asked. “Get real. Nobody even uses them anymore. They're—”
“You're being charged with reckless endangerment,” said the cop. They reached the airlock, and both cops stepped inside first.
Todd briefly thought about running, but then he really would be in trouble. “Endangering who? Myself?” he asked as he stepped in after them. The door closed, and air began to rush into the elevator-sized chamber. It took a moment for his eyes to adjust to the dimmer light.
The cop said, “Endangering yourself, the two of us, and the emergency rescue team that's waiting inside in case one of us got in trouble out there.” The tone of his voice lowered as the air pressure rose. That didn't make any sense to Todd; the suits maintained a full atmosphere no matter what the outside pressure, but then the other cop let out a deep breath and Todd realized they were both nervous about being outside. They didn't see it as an adventure; they just saw the danger.
“You're afraid of vacuum,” he said.
“We're not afraid of nothin',” the other cop said. He grabbed Todd's arm and yanked him backward, as if that somehow demonstrated his bravery.
The airlock's interior door swung away and the cops pulled him into the prep room, where half a dozen more people stood around in pressure suits, their helmets removed. They all looked at Todd as if he were an alien. The cops took off their helmets and stared, too.
“You should see your faces,” Todd said. “All I did was go outside.”
There was one person not in a P-suit, a woman about his mom's age, with an expression a lot like his mom's when he had been bad. “I'd advise you to keep quiet,” she said. “You're already in enough trouble as it is.”
“Who are you?”
“Alicia Stayton, attorney at law. I specialize in juvenile mischief cases.”
Todd laughed. “That's what you think this is? Juvenile mischief? Look, lady, all I wanted to do was go outside the habitat for once in my life. I didn't mean to get everybody all excited, and I definitely didn't intend to cause ‘mischief.'”
“What did you expect to accomplish by going outside?” asked one of the cops.
“Don't answer that,” said the lawyer.
“I didn't expect to accomplish anything,” Todd said. “Except see the landscape with my own eyes. I wanted to feel the freedom of the great outdoors.”
“Freedom?” asked the cop.
“Yeah, freedom,” Todd said. “You know what freedom is? We used to have that before everybody got scared of their own shadows. I read about it in a book.”
“Be quiet!” the lawyer said. “You have no idea how much danger you're in.”
“For talking about freedom? For taking a little bit of it for myself?” He looked at the cops, at the cop-rescue team behind them, and said, “Ah. I get it now. That's what this is really about, isn't it? I messed with your authority. Well, go ahead and re-establish it. Arrest me. Let's get this into the news. Let's get people talking about freedom again. Pretty soon there won't be enough cops to keep us all inside.”
The two cops looked at one another. The rescue squad took a couple of steps backward, all at once, as if they had drilled the move. The lawyer shouted, “No, he doesn't mean that!”
“Mean what?” Todd asked.
The cop that had yanked his arm said, “Do you intend for your illegal act to influence government policy?”
“Don't answer!” said the lawyer. “You have the right to remain silent.”
Todd looked at the cop. He didn't like the expression on the guy's face. But Todd had just been outside, something practically nobody even considered doing anymore, and he couldn't resist saying, “Government policy could use a little influencing.”
“I tried to help you,” said the lawyer. She backed up against the rescue squad, then turned and fled down the corridor.
The cop pulled his gun out of its holster. “That's terror talk, son. Trying to influence government policy through illegal acts, especially acts that endanger people's lives. That's been the definition since 2007.”
He raised the gun. Todd tried to say, “Wait!” but it just came out a squeak. The barrel of the gun looked big enough to put his head in.
I just wanted to go outside, he thought.
For an instant, the tip of the gun grew brighter than the Sun.
Copyright (c) 2008 Jerry Oltion
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* * *
Short Story: JUNKIE
by Maya Kaathryn Bohnhoff
* * * *
Illustration by Lauren Harden
* * * *
Before you can seize an opportunity, you have to recognize it....
* * * *
Matty Gurkow looked out into the eternal stars (well, cyclic anyway) and sighed with longing for them. When he'd first accepted his post aboard the Terrapin he had imagined that just being able to see the stars from Earth orbit would satisfy that longing, but the views changed little and with utter predictability. Every time an interplanetary craft would jet by on its way to the colonies, he would wish with all his heart that he had kept better grades in school and been a bit more careful about physical fitness.
He'd failed to make the cut as either scientist or astronaut, and so he must be content to trundle about in high Earth orbit as a hard-systems tech on a mundane, over-sized barge.
“Acquisition tech"—that was his official title. All he had acquired out here was an unhealthy taste for fast food (the only kind there was in an orbital), and an unequally unhealthy fantasy life that centered around First Contact and endless five-year missions.
Matty was a child of Star Trek—the seventh generation—and his quarters showed that. Models of every movie and TV starship since the original Enterprise flew at the ends of near-invisible nanowires from the ceiling of his quarters. His wall bore projections of space- and planetscapes. His shelves were cluttered with what he called “space swag"—artifacts collected from some of their recoveries that held absolutely no appeal for anyone but Matty Gurkow. His five crewmates thought him a complete dweeb. They were absolutely right. But he wasn't merely a dweeb—he was an archetypal dweeb.
The six-person team worked in three shifts of pairs, trading off pairing so as to avoid “personnel problems.” They rotated planetside every two months for two weeks.
Matty was using his shore leave to further his education and his health. He would get off this barge one of these days and emigrate to one of the colonies where exciting things had at least a possibility of happening. Things more likely to result in seeking out new worlds, as generations of Trekkers had dreamed of doing. He was looking forward to his next shore leave, during which he would complete the residency requirement for his bachelor's degree in astroengineering. Something that would bring him one step closer to being qualified to maintain and repair propulsion systems for exploratory craft.
“Doin’ your homework, Matty?”
Matty glanced up from his notebook to see his shift-mate, Janine Dukakis, peering over his shoulder.
“Yeah.” He held up the pad. “Orbital mechanics.”
“Aren't you already an orbital mechanic?”
“Very funny.”
Janine plopped down next to him at the scanner console and looked out on the vast sweep of stars visible beyond the wrap-around “window” of the bridge. It wasn't a window, really, but rather a viewscreen of sorts. You could get the realtime external view, but you could also get magnifications up to one hundred times in any direction, or a tactical display, which
came in real handy for tracking EVAs. Just another of the things Star Trek got right.
“You ever dream of going out there, Janine?” he asked her. Janine was new to the crew of the Terrapin, and he knew very little about her except that she was pretty in an unconventional, no-nonsense sort of way and had a laugh that could peel the paint off a bulkhead at thirty paces.
She flipped her long, dark brown braid over one shoulder. “Used to. Not so much anymore. Glamour wore off, I guess. You?”
“I'm working at upgrading my profile so I can maintain extrasolar systems.”
“The stars still call your name, huh?”
“It's different out there,” Matty said.
“Oh, right. You get to stare at a black void with different pinpricks of light. Very heady stuff.”
“Yeah, but to set foot on other worlds...”
“For a couple of hours or a day, at most. Then you have to trek back again.”
Matty was a little annoyed with Janine's banal attitude. To him, space was still sacred—still “the heavens.”
“So what would you rather do?” he asked peevishly.
Her face lit up. “Deep-sea diving. I've been getting my scuba certification on shore leave. I figure to join a professional salvage team, or maybe study marine archaeology.”
Matty tried not to curl his lip. Backward-looking field, archaeology. “I guess I'm more future-oriented,” he said. “Making First Contact...”