Analog SFF, June 2008
Page 15
“I didn't mean to bust you up before, all right?” she said, as we both strapped into our seats. She had left her virtching glasses behind, since we did not want to be blasting our network at the Greete positions, and she had the uncomfortable look of someone who feels unplugged. “It was a botch up. But you'd best do this thing right. You understand?”
I said nothing.
“Really, Professor,” she continued. “There are people on this ship who would like to blow you out the airlock if you don't set things aright. And I think the captain would feel inclined to let them.”
“I understand.” But I was trying not to be concerned any longer with the captain. His kind would pass. As would my kind. Better generations would follow.
“Everyone ready?” Tarkos asked with boyish enthusiasm as he snapped at buttons, running through his preflight check.
“Yes,” Ryan and I said simultaneously.
With a faint shudder, the glider disconnected and began to fall toward Purgatorio.
“Intergalactic diplomacy, here we come!” Tarkos yelped.
The Greete were expecting us. They had accepted our call for trade negotiations and understood our offer. I didn't know if we would be able to make a deal. I didn't know if I had done the right thing. But it was done now, and I would do everything in my power to try to set up the symbiotic relationship—our carbon dioxide for their oxygen—that would let us mine matryoshk for a year.
And then we would return to Earth, where I would stand trial. I had one defense: I did what I believed I had to do. I clung to the thin hope that someone on the jury would agree.
A series of metallic clangs sounded against the glider as it dropped: the remora probes were leaving the ship and latching on to us.
“Bloody Galactic snoops,” Ryan muttered.
I gave her my toothless smile. “The humans are finally doing something interesting.”
Copyright (c) 2008 Craig DeLancy
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* * *
Poem: ON THE EVOLUTION OF GOD
by Robert Lundy
All major species, through the years
That measure out their long careers
Have little concept of the flow
Of geologic time, and so
Believe their world lately started,
Can't conceive themselves departed,
Think they've lots of time to spend,
Believe their world is without end.
—
In the Cambrian explosion in all areas and spots,
Things the Earth had never seen before appeared in carload lots.
If dominating life forms show the image of Almighty God,
Their Intelligent Designer must have looked quite like an arthropod.
—
The Permian was an epoch great, the denizens of which
Were dominated by therapsids, creatures who without a stitch
Of clothing on persisted for millennia convinced that they
Resembled their top deity in each and every single way
—
The creatures that we know today from movies like Jurassic Park
Most likely were enlighteneed and enraptured by a kindred spark.
Their Voice of God was rather loud and came out sounding very roarish,
And emanated from a pair of jaws that looked Tyrannosaurish.
—
It therefore should not cause surprise and oughtnt't make a skeptic gape
To note that in the present day Almighty God's a naked ape.
Or that some think the universe's age is but six thousands years.
And that the promise of eternity will settle all our fears.
—
When man or nature heeds its urges
And from this world our species purges
Then cats and mice and worms and krill
Will fight until one owns the hill,
Then dominance of Sea and Sod,
Will grant them leave to picture God.
His image slowly will come clearer
Until they're looking in the mirror.
—
Extinction, then, will come along
To silence our successor's song.
For as Lord Keynes once rightly said,
“In the long term, we're all dead.”
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* * *
Reader's Department: THE ALTERNATE VIEW: THE RETURN OF THE WARLOCK'S WHEEL
by Jeffery D. Kooistra
Any boy standing atop a cliff feels an irresistible urge to see how far he can throw a rock from it. When I lived in New Mexico, a land richly endowed with cliffs, I indulged that urge myself many times.
When I threw those rocks, I wondered about just what angle I should be throwing them at to maximize the distance they'd go. If you're on a flat plane, the launch angle that will maximize distance is 45 degrees (neglecting air resistance). At a steeper angle, the rock goes higher, but it lands closer to you. At a shallower angle, it simply hits the ground sooner.
“What is that optimum angle when you're throwing a rock from a cliff?” I wondered. I assumed the angle only depended upon how high the cliff is. I set up the problem with the appropriate equations, and tried to solve for the optimum angle in terms of the cliff height. I found an equation all right, but I was confused as to what it meant. But in those days I was in charge of the high school computer lab, so I programmed three Apples to chew over the equation and spit out optimum launch angles for assorted height values, and left them running all night.
The next morning I pored over the data and was surprised to find that the optimum angle depended upon more variables than just the height. As noted, on a flat plain you throw your rock at a 45-degree angle to maximize the distance it will travel downrange. To calculate how far that distance is, you need to know how fast the rock will be going when it leaves your hand and the local value of g (g being the acceleration due to gravity). Plug those values into the equations with a launch angle equal to 45 degrees and out pops the distance. The thing to note is that throwing the rock at 45 degrees is going to maximize the distance and it doesn't matter how fast you throw the rock, nor whether you throw it on the Moon, Mars, or Mesklin.
But when throwing a rock off a cliff, that distance-maximizing angle not only depends upon how high the cliff is, but now also depends upon how fast you throw it and what the local value of g is. Now it does matter what planet you're on!
By the time I went to teach my classes that day, I fully understood what the equation I'd found had been trying to tell me. More importantly, I learned the value of seeking out all of the interlocked variables that might be relevant.
Learning that lesson came in handy ten years later when I was trying to figure out the Marinov Motor. I discussed my work on that thing back in a two-part Alternate View, “The Marinov Motor & Me” which appeared in the February 1999 and April 1999 issues respectively. Around the time those articles saw print I also began working for Infinite Energy magazine, continuing my study of the motor and making my mark in the world of weird science.
Weird (or alternate) science has several “holy grails,” among them gravity control, limitless free energy, a faster-than-light drive, and the “unidirectional” or “reactionless” drive. My Marinov Motor research had led me to the conclusion that, though a unidirectional space drive was out of my reach, maybe a unidirectional motor was not. That is to say, if the net push of the stator on the rotor made the shaft rotate, say, counter-clockwise, and the net push of the rotor on the stator was also in the CCW direction, then I should be able to hang the thing from the ceiling on a monofilament line and have the whole unit accelerate in the CCW sense with no mechanical part of it rotating in the other d
irection.
So why did I think I could do this? I came to believe that the Marinov Motor, and my own version called “The Warlock's Wheel,” was just a variant of several other odd motors already known to work. The first is the simplest of the unipolar motors, the one-piece Faraday motor. Take a conductive cylindrical rod magnet, arrange things so that it can freely rotate on its N-S axis, put one brush in contact with the outside surface and another in contact near the axis, and it will rotate. The question is: “What is the magnet pushing on to make it rotate?” Some think the magnet pushes on the external circuit. Most believe the magnet reacts with the current flowing through its interior, essentially pushing on itself. Weird, huh?
Another odd motor is the Feynman carousel, discussed in section 17-4 and at the end of section 27-11 of volume II of The Feynman Lectures on Physics. Mixing straight quotes from section 17-4 in with my own descriptive modifications, consider a thin plastic disc supported on a concentric shaft with excellent bearings, able to rotate freely. On the disc is a superconducting coil of wire in the form of a short solenoid concentric with the axis of rotation, in which current is flowing. Near the edge of the disc, spaced uniformly about its circumference, are a number of small metal spheres insulated from each other and from the solenoid by the material of the disc. Each sphere is given an identical electrostatic charge. Everything is stationary; the disc is at rest.
Initially, the angular momentum of this motor is zero, right?
Allow the temperature of the solenoid to rise above the critical point until it is no longer a superconductor. While the current was flowing, there was a magnetic flux through the solenoid more or less parallel to the axis of the disc. Now with the current flow interrupted, the flux must go to zero, and an electric field is induced which will circulate around in circles centered on the axis. This field exerts a force on the charged spheres, tangential to the perimeter of the disk, and all in the same sense. This results in a net torque on the disk and it starts rotating. Since no one pushed the carousel to set it spinning, we conclude that angular momentum now apparent was stored in the magnetic field.
That's pretty cool if you think about it. Suppose you started current flowing in the solenoid somewhere else, and only later inserted it into the plastic disc with the charged spheres. Angular momentum stored in a magnetic field is just as portable and real as it is in a spinning gyroscope.
The Warlock's Wheel is also simple. I describe it better and with a diagram in my April 1999 Alternate View, but I'll briefly describe it here. Take two very strong rectangular cross-section neodymium-iron-boron (NIB) rod magnets and put them side-by-side so that the north pole of one adjoins with the south pole of the other, top and bottom. (If you're using the right magnets, they'll do this all by themselves once you bring them near each other, so watch out!) Put this magnet pair on an axle oriented vertically so that it's free to rotate on its long axis. Around the pair suspend a copper ring, inner diameter twice the width of the magnet pair, outer diameter half an inch more, coaxial with the magnets and centered horizontally between the top and bottom. The magnets and the ring are free to rotate independently of each other.
To demonstrate the peculiarity of the motor, start with the unit at rest. The brush contact points on the left and right sides of the exterior ring rim are collinear with the axis and the center points of the magnets. When current is introduced through the brushes, it enters on one side of the ring, splits in two, and rejoins and exits on the other side. The magnet pair will begin to rotate in one direction, and the ring will begin rotating in the opposite sense. Now reset the motor to the initial state, but make the brushes touch the ring on the interior rim. Turn on the current and both the magnet pair and the ring will begin to rotate in the same direction.
The first time I did this experiment I was so shocked I just went outside and cut the grass. At the time I wrote my two-part article, I didn't understand how the motor worked, but I figured it out later. I concluded my motor was much like Feynman's carousel, only with strong permanent magnets and switchable electric currents.
I became convinced that a unidirectional motor could be built, but what I didn't know was whether I could build one. I did fashion a crude version of such a motor out of NIB magnets and wire wrapped on a six-ounce disposable coffee cup and it did seem to exhibit the expected unidirectional behavior. But it was so crude it was hardly ready for a formal presentation and its performance was erratic enough that, had someone else built it, even I would not have found it a convincing demonstration of a unidirectional motor. (I described a souped-up version of this motor in my story “Nova Terra,” which appeared in the January/February 2004 Analog.)
How to improve it? Since my first attempt had “sorta worked,” this told me two things. The first was that I was on the right track; the second, that there must be many ways to make a model that “sorta works.” I didn't want to build a dozen more prototypes with no certainty that the next one would work any better than the previous one. I did a great deal of hard thinking about how to make the next version, but I kept finding myself up against that interlocking variables problem.
For instance, with my first model, I found it desirable to replace the ring with a complex winding consisting of ten turns of copper wire. You might think that if ten turns works a little, maybe twenty will do twice as well. But it doesn't work that way. I knew before I built the first one that the fewer windings I could get by with, the better. But when I tried to figure out “What is the ideal number of windings?” I discovered that the question had no simple answer. To answer it, I needed to know how strong the magnets were, what all of the dimensions of the motor were going to be, what the wire diameter would be, how much current was going to flow, what the drag of the brushes on the commutator would be ... It was the rock thrown from a cliff problem all over again, only worse. A hopeless morass of interlocking variables, and this time I lacked the computer skills to even begin to write a simulation to help me out.
* * * *
When I left Infinite Energy magazine I stopped working on the Warlock's Wheel, but I'm starting to again. I don't expect to make anything practical, although I would like to get a journal article out of the research. Perhaps something suitable for The Physics Teacher or even the American Journal of Physics. But mostly I'm going to work on it because my son Joshua has begun to show an interest in physics, engineering, and electronics. If you want your child to behave a certain way, at the very least you must model that behavior yourself. I want my son to grow up with memories of his dad doing interesting experiments in a basement lab, and hopefully of helping me, too.
That's a variable I can control.
Copyright (c) 2008 Jeffery D. Kooistra
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* * *
Short Story: BACK
by Susan Forest
Sometimes attention to detail is really important....
It was while Alan and Victor were touring the warehouse with the real estate agent that a slip of paper bearing the words, “It worked,” materialized on a desk in the office.
Alan stared at the note, strength draining from every muscle in his body as disbelief turned to realization, then to euphoria.
“Alan—” Victor swallowed, turning white as the paper, his eyes wide beneath unruly curls.
Alan lifted the note and fingered its crisp, white softness. It was real. Real.
“We haven't started the experiments yet.”
Thirteen years—thirteen goddamn years of hope and faith. And now, Alan's belief in Victor had been borne out.
Victor turned to the real estate agent. “We'll take it.”
* * * *
“This proves it.” Words poured from Alan's mouth, out of control, as he paced the room. “It's going to happen, Victor. The world has changed. It has.”
“Well, something's happened,” Victor conceded. He snapped his laser measure closed and knelt on the concrete floor to record the width of the West Vancouver warehouse in his note
book.
Alan squatted in front of him, next to the wall. “And no one knows it but you and me.”
It was pushing ten o'clock, and neither of them had thought to go home. The warehouse was dusty and dark, lit by a half dozen fluorescents high above their heads and the sound of traffic and trains filtered in from beyond the aging brick and lumber walls. The real estate agent, frightened and suspicious—but ten thousand dollars richer—had left with their signed lease hours ago.
Victor pushed his stylus behind his ear. “We still have to build the time machine and send that paper back to today's date. The experiment isn't done until we do.”
“But we know the results. The rest is just technical.”
Victor eyed Alan. “Maybe.”
“Maybe?”
“We can still screw up, Alan.”
Alan slapped the paper as proof. “Look at it. How can you be so skeptical?”
Victor frowned in annoyance. “Put the paper down before you wear it out. If this turns out to be what we hope, that's a valuable archive you've got your biodegrading sweat on.”
Alan hurried to the office, holding the evidence gingerly by one corner and put it in his briefcase, letting his eyes linger on the handwritten scrawl for one last moment. Then he whirled back to Victor, who was on the floor, pointing the laser measure at the ceiling.
“What do you mean, ‘maybe'? How could this paper appear out of nowhere, unless we sent it back in time?”
“Lots of explanations. Maybe someone's working on a molecular transporter or duplicator. Could have been someone else also working on time travel. There's been sufficient data in the world archive since 2032 for anyone to access.” Victor collapsed the laser beam. “We have competitors, you know, Alan.”
“Competitors with a paper marked, ‘It worked,’ in my handwriting?”
Victor pulled himself to a sitting position and pushed his long curls away from his glasses. “Alan, you set your heart on things. I don't want you to be disappointed. I don't want you to give me credit for being a genius when so many things can still go wrong. It's possible to want something so badly you miss the obvious, you know.”