Twistor (28 page)

Paul rubbed his chin and nodded.

'I got a chemistry grad-student friend to run a mass spectrograph scan on an ash sample from the wood,' said Vickie after she was sure they'd digested the first piece of information. 'She discovered that the isotope ratios are all wrong. There's far too much carbon 13 and not enough magnesium 26, for example—'

She was interrupted by the ring of the telephone. Paul jumped, startled. His fingers began to drum again. Elizabeth answered the phone, then called Victoria. She talked quietly for some minutes, making notes on a small pad from her purse. Then she returned to the dining table.

That was another friend,' Vickie said. 'She's a grad student in forestry. I convinced her to drop what she was doing to perform an electrophoresis bio-assay of a pulped wood sample for me. She sounded disappointed. She'd heard about the other results and was expecting something spectacular. Instead, she says that the amino acids and proteins in the wood look pretty normal. About the same ratios as normal wood from Douglas fir. There's even a trace of chlorophyll in the sample. The biochemistry, with a few minor differences, looks the same as would be expected for an ordinary fir tree.'

'But there were all those other differences,' Elizabeth said.

'
Yes,' Victoria said. The wood sphere is not from any tree growing on Earth, but nevertheless its basic biochemistry is almost identical.'

Vickie noticed that Paul looked more hopeful. He rubbed his chin. 'It means that the shadow universe where they went isn't just an empty vacuum,' he said. There's life there, carbon-based life! Advanced plant life at that. Woody trees with green leaves. That kind of tree appeared on our Earth at about the same time as the early mammals, as I recall. The chlorophyll means air with oxygen in it. If that's where David and the children went, they could survive!'

Victoria nodded agreement. 'And here's another thing that might interest you,' she continued. 'I borrowed a ladder from the janitor just before I came here and climbed up on the top of the wood sphere. I wanted to get a look at it from that perspective. From above you can see clear annual growth rings, hundreds of them. The ones with the largest radius of curvature are near the north wall of the lab, and the ones with the smallest are near the south wall. The radius of curvature of the biggest rings is about eight meters. That means the tree they came from must have been at least sixteen meters in diameter. That's bigger than the biggest giant sequoias. When I was looking at the rings, I noticed something else. Near the north wall there's a qualitative change in the wood. Its color becomes lighter, and it's more moist and softer.'

Elizabeth looked thoughtful. 'That's how the sapwood looks near the cambium layer,' she said. 'You know, the living and growing part at the outside surface of the tree that's just under the bark. Perhaps if they are inside a big tree, there's a chance they can get out. David's very resourceful.'

Victoria thought for a moment. 'David might just have the tools to do that.' She remembered the equipment in Sam's number-three toolbox, which had disappeared along with David and the children.

'
Your bio-assay bothers me, Vickie,' Paul said. His voice sounded more normal now. 'It's altogether too Earth-normal. Could a separate biochemistry that similar to ours actually have evolved in a shadow universe in complete isolation, right down to the same amino acid ratios?'

'That's rather unlikely,' said Elizabeth. 'It's more probable that there's some kind of connection that allowed the two biosystems to cross-seed each other.'

Paul nodded, but Victoria frowned. 'That isn't possible, Paul, is it?' she asked.

'Maybe it is,' said Paul. 'Yesterday I noticed something very interesting that gives me an idea.' He looked from Vickie to Elizabeth. 'Have you ever heard of plasmoids or ball lightning?'

'I actually saw ball lightning once,' said Elizabeth. 'It was years ago. Some friends and I were camping in the Colorado Rockies when lightning struck a tree near us. After the lightning stroke a ball of blue light ran right down to the bottom of the tree and then very slowly bounced above the ground in big arcs until it went into the lake and disappeared. There was a round burned spot on the ground at each place it had hit, and it made a cloud of steam when it hit the lake. It was spooky.'

'I don't know about ball lightning, but I've read about plasmoids,' said Victoria. 'A plasmoid is a kind of self-sustaining plasma that generates its own magnetic confinement field, right? A sort of self-contained ball of magneto-hydrodynamic energy.'

'Right,' said Paul. 'There've been random observations, but no one's ever been able to do a careful study of ball lightning or to produce it in the laboratory. Too much energy needed. The prevailing view is that ball lightning's an extremely energetic plasmoid that's occasionally generated by a lightning stroke, so energetic that it can survive at atmospheric pressure.'

Elizabeth
nodded. Tine, dear, but what does this have to do with our present problem?' she asked.

'Yesterday I happened to notice that the electromagnetic structure of a plasmoid is very similar to that of a twistor field. Plasmoids don't rotate, of course, but otherwise they're almost identical.'

That's amazing,' said Vickie. 'Nature discovered the twistor field before we made one.'

Paul nodded. 'Now suppose,' he continued, 'that a lightning ball like the one Elizabeth saw just happened to hit the ground and bounce in just the right way, so that the electromagnetic field was rotated at just the right rate. Then, by a very improbable lucky accident, it might twist everything in the field volume into a shadow universe or from a shadow universe into ours. Probably only tiny organisms like bacteria or moss or mold or fungus spores could survive such a twist, but it would be enough to couple together the evolution of life, at least the early stages, in any parallel shadow systems that contained Earthlike planets.' He looked at his wife. 'Elizabeth, you know a lot more about biosciences and such things than I do. What do you think?'

'Well,' Elizabeth said, 'I don't know about the physics part of your idea, but I think that if what you described happened only once in a million years that would still be often enough to have a profound effect on the evolution of primitive plants and organisms. There are many well-documented cases in the fossil record of new organisms appearing in a very short period of time and radically changing the ecosystem. It's called "punctuated equilibrium." Your scenario might very well lead to roughly parallel evolution in both systems, at least up to the point where the organisms or their seeds and spores got too big or fragile to use the lightning balls as transport vehicles.'

Victoria nodded. She had a feeling of rising excitement. It was beginning to make sense. 'And that would explain,'
she
said, 'why the biochemistry of the tree wood is so similar but the details of the wood structure are so different. Convergent evolution up to a point, then evolutionary divergence. The shadow universe sounds like an interesting place. Similar but different. David and the children could survive in a place like that if they were careful.'

'Paul?' asked Elizabeth, looking perplexed. 'How could another planet occupy the same space as the Earth? I mean, wouldn't the gravity be doubled or something?'

'I worried about that when I realized the big wooden sphere in the lab must have come from an Earthlike planet,' said Paul. 'I think there's a way out. Geophysicists have always had difficulty in explaining how the Earth could be so dense inside. Its center is supposed to have about ten to fifteen times the density of the crust. Even if the interior is mostly iron-nickel under huge pressure, it's still difficult to account for such a big density. It's an old problem that geophysicists have learned to live with and ignore.

'But suppose the interior wasn't iron-nickel but something lighter. Then we could accommodate two or even three Earths superimposed on one another, as long as the others are made of shadow particles that only interact with themselves.'

Vickie nodded, considering the new idea.

'So the evidence indicates,' said Elizabeth, 'that our children and David are probably in a very Earthlike world, with the same gravity as this one and with similar plant life. That makes me feel a lot better. And the children have David to take care of them.'

'It also means,' said Vickie, 'that we need to do a fast rebuild of the twistor equipment and get them back. It took David and me ten months of hard work the first time. But this time it should be much easier; I know which corners to cut and what to leave out. With enough help and enough money I could have another unit ready in perhaps a month. But that's still a long time . . . '

For
the rest of the evening, they made plans.

It was a soft, repetitive sound. David came awake from a light sleep and looked around. He held his breath, listening in the darkness that pressed against his straining eyes. The sound came again. One of the children was crying. He slipped from his sleeping bag and slid across the concrete floor in the direction of the cot where they were sleeping.

It was Jeff. He was half asleep, and he was crying softly to himself.

David put his hand on the small head. 'What's the matter, Jeff?' he asked. 'Are you all right?'

'M-Mommy.' The small voice wavered. 'I want Mommy.'

David stroked his hair. 'I know you do,' he said. 'I know you miss her, especially at night.'

Jeff sniffed.

'When you're away from home,' David said, 'it helps to be with friends instead of all by yourself. I'm your friend, Jeff, and you're here with me. I'll take care of you. We'll take care of each other. If anything scares you, or if there's anything you need, you tell me just like you'd tell your mommy.'

Jeff sniffed again. 'OK,' he said quietly.

David put his arms around Jeff and held him close. Then he settled on the floor next to him, one arm across the sleeping bag. It wasn't very comfortable, but he lay that way for a long time, until Jeff's quiet breathing became very slow and regular. Then David slowly raised himself and looked down at the sleeping child. For a moment his eyes felt moist at the corners, his throat tight. He swallowed and slipped back across the floor to his own sleeping bag.

Much later David awoke again with a start. Where . . . ? He was disoriented for a moment, then realized he was still in the treehouse. He pushed the button of his watch, flashing its electroluminescent panel. 1:05 A.M. An unfamiliar sound had awakened him. It wasn't Jeff this time.
He
tried to recall what he'd heard. Then the sound came again, a low, vibrant wail. Carefully he retrieved the pistol and the big four-cell flashlight from their places on the floor beside him and moved silently across the floor to the ragged entrance of their treehouse. He removed the crossed branches, lifted aside the sheet of aluminized Fiberglas insulation that had covered the door-hole, and extended his head slowly into the darkness outside. The rough wood pressed against his lower chest. Nothing was visible in the faint starlight.

Then the sound came again, accompanied by rustling and snuffling noises from a place near the base of the tree. He could make out the sound of deep heavy breathing. There was an animal down there. David pointed the long krypton-bulb flashlight in the direction of the sounds and squeezed the switch button.

Two widely spaced greenish yellow eyes reflected the light. The animal was big – very big. And it was well supplied with curving yellow teeth and sharp dark claws. The large mouth had a long fringe of blood-red beard around its edge. That was all he could see before the creature shuffled bearlike behind the tree, leaving the impression of a mottled brown coat covering a massive humped back. And six legs. There had definitely been six legs. David took a deep breath and replaced the doorway covering. 'Great!' he said to himself. 'Furry six-legged monsters with big teeth and red beards. That's all we need.'

The pistol in his hand looked small, inadequate. The creature had been enormous, and with that array of teeth it must be at least a part-time carnivore. It would take an elephant gun to kill something that size. The creature would hardly notice a bullet from this small-caliber pistol.

How many nocturnal carnivores are out there, David wondered. Do they climb trees and investigate interesting treehouses? He shuddered and lay back on his sleeping pad.

As
he placed the weapon on the floor beside him, he recalled the three men who had come to the laboratory the previous morning. He wondered who had sent them and why. Obviously they had some connection with the bugging incident, and they had come to steal the twistor hardware. Saxon's plans for moving the apparatus, if known to these people, might have made a hijacking look easier. All they would have to do was come first with their own moving van, before the real movers arrived. They, whoever they were, must want the twistor apparatus for themselves. And now it was out of their reach. But Vickie wasn't . . .

David didn't sleep well. The questions in his head kept demanding answers. What was happening now? With himself and the hardware out of reach, the only person who knew all the details of producing the twistor effect was Vickie. A feeling of helpless dread gripped his abdomen. Vickie. She must be in great danger. And he could do nothing even to warn her. His thoughts revolved about Vickie for the rest of a long, sleepless night.

There had to be something he could do.

18

Thursday Morning, October 14

Vickie was feeling apprehensive as they approached the office of the department chairman. After their strategy discussion last night, Paul had called Weinberger and asked him to arrange a meeting for this morning, to be attended by the three of them and Allan Saxon. Now Vickie was wondering if the meeting had been such a good idea. She had the sinking feeling that she was well out of her depth at this level of departmental politics.

But as they entered the physics office complex Weinberger greeted them very cordially, almost as if they were old friends he was meeting at the airport. As they entered his large office, he asked Paul in a quiet voice if there had been any word from the police about the children. Paul looked down and shook his head. Along the north wall a long walnut table was placed near the tall windows looking out on the gothic face of the library beyond. Weinberger directed them to seats at the table.