It was not very neat, but after all this was only a test prototype, to see if a small twistor field could be generated on battery power. At the edges of the perf-board dangled about a dozen silvery potentiometers, three wires leading from each to the prototype while their shafts rested on the table top. The function of each pot was scrawled in black letters across its shiny black surface.
David connected wires from the prototype to the bank of flashlight batteries he'd assembled. Then he quickly did some power-up checks using dummy loads for the twistor coils and observing electrical wave shapes with Sam's small LCD oscilloscope. He noticed an interesting effect. When the feedback loop gain of one of the operational amplifiers was set slightly above its proper value, it tended to oscillate. This had the consequence of making the twistor rotation sequence advance continuously. He'd seen the effect before. It had been responsible for their first 'vacuum improvement' indications of the twistor effect.
He considered. For the gadget he was planning to build, this bug might actually be a feature. It might, with luck, allow him to 'peek' through the field sphere, seeing light and perhaps even hearing sounds from the other side. David scribbled some changes on the circuit diagram, adding two integrated circuit chips and another switch to the design. He continued with the power tests until he was satisfied. It was looking very good. He cut power.
Then he connected the twistor coils he'd carefully wound and set in epoxy the day before. They were curved sections of spherical surfaces, scaled-down versions of the useless big ones that still stood in the center of the room on their large wooden supports like some inept attempt at post-modern sculpture. He reconnected power and pushed a red button mounted on the perf-board. Nothing.
He'd screwed up, cut too many corners in the design, he thought ruefully. Or perhaps . . . perhaps he just needed to increase the positive feedback coupling. He twitched the feedback potentiometer clockwise and made a note in the open lab notebook beside him, then made two measurements with the ohmmeter and noted them.
He reconnected the batteries and repeated the earlier checks. He pressed the red button and watched the candle flame through the little coils. The region between the coils might have wavered infinitesimally, creating the illusion of a very slight dimming of the candle flame beyond. Good! He turned another potentiometer clockwise, watching the faint darkness between the coils near the flame as it deepened, then lightened, then grew very dark indeed. He smiled and disconnected the batteries, made more notes and more ohmmeter readings. He would need this information if a portable unit was to be built.
Finally he reconnected the battery bank, pushed the red button to verify that the darkness still came, and reduced one of the pots until a black mark on its shaft matched a similar mark on its threaded sleeve. He inhaled and pressed the red button. There was a quite audible pop! sound.
David quietly disconnected the batteries again. He stood up, stretched, and looked down again at the untidy prototype. The damned kludge actually worked! He had a functioning twisting device. He stood quietly for a time.
Then he yelled 'Yaa-hoooo! Yee-haaaaaaa!' and jumped up and down. Sound completely filled the treehouse echo chamber.
Melissa, who had been asleep for hours, sat up and looked at him in amazement. Jeff turned toward him and stared.
David hugged them and told them that everything was OK, that everything was wonderful, that he would tell them in the morning.
They went back to sleep. David, weary but happy, curled up on his mattress too, thinking what he'd do if they returned. When they returned.
* * *
Jeff needed to go to the bathroom. David had arranged a plastic garbage can behind the gray cabinet as a 'nightjar,' but Jeff didn't approve of this substitute for sanitary facilities. He decided that, although David had warned them that dangerous animals might be outside at night, he would use the new latrine David had made behind their tree. Quietly he took the small flashlight David kept on the table, walked to the door-hole, and unfastened the cover. The rain had stopped and a half moon was out between the trees, low in the southwest. It was a funny moon, about the same size as the one he remembered at home. But it had two big dark craters just above the dark part that were like eyes, watching him. It made him feel a little scared. He silently lowered the ladder, climbed down, and walked through the slanting moonlight to the latrine below the tree.
As he was finishing, he heard a rustling sound. It was coming from the bushes on the left. Jeff shined his little flashlight in that direction. Two yellow eyes, large and very widely spaced, looked back at him. The rustling sound increased, and Jeff could see that below the large eyes there was something else . . . long red and pink worms were hanging down, thrashing furiously in the underbrush. Then there was a growling noise that rose in both loudness and pitch. Jeff backed away around the tree.
His retreat was a signal to the animal. It broke from the bushes with a loud crashing of branches. Jeff screamed and ran for the ladder. He climbed very fast. When he was about half way to the door-hole he looked down to see an enormous bearded animal standing below, bellowing out an unearthly wail in his direction. A very large forepaw reached for him, and he saw, as if in slow motion, one curving black claw cutting a piece of rubber from the heel of his lower sneaker. He was terrified. He climbed very, very fast then, plunging into the door-hole screaming. He could hear the scraping, scrabbling sounds of the animal as it climbed the tree behind him.
As Jeff ran across the floor, an enormous head, outlined by moonlight, swept aside the Fiberglas batting that hung over the door-hole. Jeff, screaming, huddled behind the gray cabinet and shined his light backward. It was horrible, with big yellow teeth and pink and red wormlike things crawling around the edges of the great gaping mouth, beckoning him to come inside. The great fangs and writhing mouth were joined by an enormous clawed paw that reached through the hole and extended in his direction. Jeff retreated further, shrieking as he went.
A red spot appeared between the eyes of the large head. There was a shot and an answering explosion. The head jerked and twisted sideways. There was an unbelievably loud roar of outrage. The red spot moved again and there was another shot and a bright explosion at the center of the large head. Then three shots more in rapid succession. The final one pierced a huge eye, and there was a muffled explosion from inside the great head itself. It recoiled backward and disappeared, replaced by silvery moonlight. David stood and walked to the door-hole, the black pistol in one hand and a flashlight in the other. Jeff joined him at the door-hole, standing very close to David. Then, gathering his courage, he put his head out through the hole and looked down.
David shined the light down on the sprawled shape of the large animal twitching on the ground below. 'Well, Jeff, it looks like we'll have a supply of meat for a while. I was getting tired of fish anyhow. Are you OK, Jeff?'
Jeff nodded. He was very glad that David was there. He put his arms around David's legs and held on tight. After a while he felt better. He resolved always to use the nightjar after that.
22
Saturday, October 23
David sat on the huge branch near the door-hole of their treehouse, his back against the trunk of the tree, one leg dangling. The birdcalls from above attracted his attention. Sunlight filtered through the overhead leaf canopy. High on the tree trunk David could make out the green shape of the treebird, busily rendering its services. The air smelled fresh and wintry now. Only yesterday it had reeked of 'shadow-bear' carcass . . .
After photographing Jeff with his large friend, David and the children had spent most of the previous day in skinning and butchering the animal. It wasn't actually a bear, of course. Its bearlike similarity was ruined, for example, by the ruff of long thin tentacles that surrounded its mouth, a pink-and-red fringe that gave the animal a bearded appearance. The tentacles might be useful, he suggested to the children, in foraging for food.
David had planned to provide an anatomy lesson for Jeff and Melissa while he was butc
hering the bear, but the organs were like nothing he had seen before or could have imagined. The smells given off by some of the strangely shaped innards were equally unimaginable. Blueflies, the blue flying insect-creatures, had particularly appreciated the more odoriferous items. He had salvaged all he could from the carcass. Then, using a system of levers and pulleys, he had dragged the massive remains some distance into the forest. He wanted to avoid attracting scavengers to their campsite.
After the butchering and dragging, David made a partially successful attempt to wash the bear-juices from his skin with cold water from the cistern. There was no shortage of water for now. The cistern was nearly full from the recent rains. But they were running low on soap, and David found that he still smelled a bit like bear, even to himself. He swatted at a bluefly. How well, he wondered, could one make soap from bear fat and ashes? He must start experimenting soon.
David looked down. Below, Jeff was stirring a nice shadow-bear stew that bubbled on the cook fire, and he occasionally turned the strips of shadow-bear jerky that were smoking under the aluminum foil hood. It was probably good therapy. Jeff had awakened screaming from a nightmare the night of the incident, but last night he had slept peacefully. It probably soothed the psyche to dismember and eat the things that scare you.
David glanced at the objects in his lap. He'd been sitting in the sunlight working on a smaller, portable version of the prototype twistor generator. It had been only late yesterday afternoon that David had been able to resume work on it. He held up the board. Not bad, he thought. The clutter of the prototype breadboard had been simplified and concentrated into a single narrow rectangle of perf-board, dense with small op-amp chips and larger digital LSI bugs, their little legs poking through the perf-board holes to be laced together underneath with many-layered zigzags of pale red wire. At the edge of the board a row of small in-line potentiometers were arranged neatly.
He tested the fit of the circuit board to the length of gray PVC pipe that was to be its housing. The fit was neat, and the row of holes in the pipe lined up nicely with the pots. David checked the contacts of the four power transistors set in horned heat sinks studding one side of the pipe. No problem there. He took a black Sharpie pen from his shirt pocket and, bracing an arm against the tree, inscribed in minute letters a neat label at the right of each hole. Just a bit more work and the thing would be ready to test.
Below, Melissa walked around the side of the tree. She'd been acting rather mysterious lately, David thought. She was carrying something dark. 'David!' she called. 'Come down! I want to show you something.'
He descended the ladder. As he turned at its foot, Melissa approached him. 'Whatcha got, Melissa?' he asked.
Melissa extended her hands, holding something out before David's face. Sitting pertly in the bowl her hands formed was a small brown animal with big pointed ears and two oversize violet eyes. It's cute, David realized.
'This,' she said, 'is a shadow kitten. His name is "Shadow." He likes fish. He eats shadow-bear meat too, but he prefers fish.' The small brown creature, its hind legs and tail folded under it, sat propped on its middle pair of legs. It showed its pink tongue and held its little brown forepaws upright. They ended in two tiny six-fingered hands. Except for the extra finger, the hands might have belonged to a human baby.
A bluefly buzzed near David's nose. The brown creature's hand darted, so fast that it appeared before David's face without seeming to have moved there. The bluefly was held firmly between the brown thumb and the first small finger. Then Shadow delicately separated the large blue abdomen from the bluefly and extended its little hand, offering it to David. David backed away, shaking his head. Shadow blinked, then placed the morsel delicately on its own pink tongue and swallowed. With its other hand it casually tossed away the head and thorax of the bluefly. The expression on its small face might have been interpreted as one of amusement and satisfaction. Like a shrimp, David thought. You eat the back part and throw away the rest.
'Shadow catches minnows like that, too,' Melissa said. 'He's very quick.'
Solemnly David extended an index finger, which was duly gripped by the little hand. 'Hello, Shadow,' he said as the creature squeezed his finger. 'I'm pleased to meet you.' He had a feeling of unreality as the small creature nodded its head, made a high-pitched chattering squeak, and changed its color from brown to green. He had the distinct impression that Shadow was pleased to meet him also.
It was getting late, David thought, looking across to where the children were sleeping. The little brown animal was awake, however. Shadow was seated on the work table near the reflector-hooded candle, watching with untiring attention as he worked.
David looked at his watch. After 1:00 A.M. But the mini-twistor unit was about ready to try. He clipped the small digital ohmmeter to several spots on the perf-board strip and adjusted the resistance of each pot to the nominal values he'd taken from the prototype. Nothing left but final assembly.
He slipped the electronics-laden strip into its PVC-pipe jacket, then fitted the pipe into the modified barrel of the big four-cell flashlight. The gray PVC extended the cylindrical shape of the flashlight for another twenty centimeters beyond the point where the flashlight lens would normally go. On one side of the flashlight's on-off switch, which retained that function, were mounted three small red push buttons which David had labeled PEEK, TALK, and TWIST. At the other end of the PVC pipe a cup-shaped array of curved copper coils, about the size of half a grapefruit skin, had been fixed in place with clear epoxy. The result was an impressive gray-and-silver macelike object half a meter long with a coppery cup at its business end. David took a breath. It was time for the smoke test.
He slid the on-off switch forward. A green LED labeled POWER lit on the gray barrel. Nothing else happened. OK. He sniffed at the row of holes, but smelled only cedar and curing epoxy, not burning parts. Good. Like a priest kissing a sacred object, David touched his lips to the line of external power transistors. They had now warmed to about body temperature, but no higher. Fine. He squinted across the cup at the candle flame and pressed the small red TWIST button on the left. Nothing. He frowned.
Maybe the feedback coupling had drifted off again. Switching off, he inserted a screwdriver in the third hole and gave the trimpot behind it a half turn counterclockwise. Then he switched on and tried it again. There came the satisfying pop sound.
At the sound, the little animal looked startled. Standing on its four legs, arms against its chest, it looked around. Then, satisfied, it settled back down to watch David again.
David used the screwdriver to trim the tuning control, resetting the frequency for 'home.' Except for final calibration the thing was finished. He felt a glow of satisfaction. He preferred electronic innards to bear innards any day. He stood, walked over to the door-hole, and pulled aside the Fiberglas cover. It was dark outside, and fairly cool. Leaning forward on his knees, he extended his torso through the door-hole, the new device held before him. He brought the cup of coils at the end of the device close to his eye and sighted to the right along the curving bulk of the tree.
He'd learned from the prototype that when he made the field driver Humble' in a repeated transition, then detuned the transition field slightly, an interesting and useful thing occurred. Photons of light were diverted from one universe to the other while matter was left undisturbed. This made the device safer to use, because he didn't have to worry about sending his nose into another universe. This was what he now called the PEEK or photons-only mode. When the PEEK button was pushed you could look but not touch.
A second button, which tumbled a properly tuned twistor field, was labeled TALK. It wasn't tested yet, but David estimated that it should transmit enough sound vibration via the air passing through the continuously rotating twistor field to allow speech communication between universes. If that worked, it should be useful. The third button, labeled TWIST, produced a single twistor rotation. David had carefully tuned the unit to link with the universe from which they
'd come.
He peeked. Through the hazy sphere hanging over the coppery cup, light from the hallway could be seen coming through the frosted glass door panel of his deserted laboratory in the other universe. A huge sphere of wood occupied most of the space behind him: the treehouse cavity. He was surprised that so much weight could be supported by what was left of the floor structure.
David had prepared a note that described their present situation. He placed the slip of paper into the coil cup and pushed TWIST. The paper disappeared from the cup, and, using the PEEK button, he watched it drift to the floor of the laboratory. Then he switched the unit off. Perhaps someone would find his message tomorrow, a note from castaways stranded on a distant shore.
He would leave more notes around the building to ensure that Vickie and Paul and Elizabeth knew that he and the children were still alive. He wondered how others in the department were taking the recent events. The wooden ball must have caused quite a sensation. He wondered how much longer the batteries in this unit would continue to operate.
Batteries: that suggested something to David. Besides leaving notes, there might be another use for this little device if he could find the right places to use it. That might require acrobatics done best in daylight . . .
'Pull!' David yelled. Melissa and Jeff, below on the ground, pulled on the long guy wire that was tied to his waist. He sighted through the hazy sphere at the end of the twistor device. 'More this way!' he shouted, gesturing to the right. The children shifted their positions, changing the angle of the pull wire to swing him in the indicated direction. Jeff stepped on Melissa's heel and she dropped her grip on the wire to turn and glare at him. Jeff, still holding the wire, was pulled forward, and David's position changed in the wrong direction. Dangling from a heavy wire dropped from a large overhead branch, David was suspended perhaps six meters above the ground. This wasn't working • . .
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