Gregory Benford - Timescape

Markham twisted uncomfortably, irked by the narrow, cramped seat. Air travel was getting to be a rich man’s route again, only this time without the perks. Then he fetched his mind back from these passing reminders of the relentlessly real world. The problem was not solved, and time remained.

But is the paradox decidable at all? he thought. The German mathematician Gödel had shown that even simple systems of arithmetic contained things which were true, but unprovable. In fact, you couldn’t even show that arithmetic itself was consistent—that is, didn’t contain paradoxes. Gödel had forced arithmetic into describing itself in its own language. He had trapped it into its own box, deprived it of ever proving itself by reference to things outside itself. And that was for arithmetic, the simplest logical system known! What of the universe itself, with tachyons launching through it, threading the cloth of space-time? How could all the squiggles on all the yellow pads in the world ever trap that vast weave into the old boxes of yes/no, true/false, past/future? Markham relaxed in his brimming warmth. The plane went clunk and tilted earthward.

The point that continued to puzzle him was whether Renfrew needed to send a message at all, to make a paradox. Tachyons were constantly being produced by natural collisions of high-energy particles—that’s how they had been discovered. Why didn’t those natural tachyons produce a paradox somehow? He frowned. The plane nosed further, giving the illusion of hanging over the lip of a pit, legs dangling. Natural tachyons … The answer had to be that it took some minimum impulse to trigger a paradox. Some critical volume of space-time had to be tweaked, and then the disturbance would propagate outward instantaneously, with enough amplitude to matter. You could change the past at will, yes, so long as you didn’t make paradoxes that had large amplitude. Once you exceeded the threshold, the tachyon wave would have a significant impact on the whole universe. But if so, how could you tell that had happened? What was the signature? How did the universe pick a way to resolve the paradox? They knew they had reached the past—Peterson proved that. But what more could happen?

Markham felt a sudden stab of perception. If the universe was a wholly linked system with no mythical classical observer to collapse the wave function, then the wave function did not have to collapse at all. It—

A wrenching thump. Markham looked out in surprise and saw the ground veer suddenly. Ahead were the patient green fields of Maryland. A clump of forest swarmed beneath the wings. In the cabin, a babble of voices. Shouts. A rasping buzz. The forest went whipping by. The trees were sharp, precise, with the clarity of good ideas. He watched them flick past as the airplane became light, airy, a gossamer webbing of metal that fell with him, mute matter tugged by gravity’s curved geometry. Skreeeeeee . The trees were pale rods in the slanting light, each with a ball of green exploding at the top. They rushed by faster and faster and Markham thought of a universe with one wave function, scattering into the new states of being as a paradox formed inside it like the kernel of an idea.—If the wave function did not collapse… Worlds lay ahead of him, and worlds lay behind. There was a sharp crack and he saw suddenly what should have been.

PETERSON WOKE SLOWLY. HE KEPT HIS EYES CLOSED. His body told him not to move but he couldn’t remember why. There was a murmur of movement around him, subdued voices, somewhere in the distance a metallic clash. He opened his eyes briefly, saw white walls, a chrome rail. A whirling dizziness. He remembered where he was now. Gingerly he tested his body. A dull, cottony feel. Seeping, cold ache. The rail down the side of a bed came into fuzzy focus. He rolled his head, wincing, and saw a bottle suspended above him. He tried to follow the tubes with his eyes but couldn’t. Something was plugged into his nose. A tube taped to his arm pricked him as he moved. He tried to call the nurse. It came out a rattling croak.

She had heard him anyway. A round face with glasses and a white cap leaped into his field of vision.

“Waking up, are we? That’s right. You’ll be all right now.”

“Cold…” He closed his eyes. Felt blankets being tucked in around him. The plug was removed from his nose.

“Can you hold a thermometer in your mouth?” the bright brisk voice asked. “Or should we try the other end?”

He squinted at her, loathing her.

“Mouth…” His tongue felt furry and enormous. Something cold slipped into his mouth. Cool fingers clamped his wrist.

“Well, coming down nicely. You’re one of the lucky ones, you are. Got you some Infalaithin-G before it got to you.”

He frowned. “Others?”

“Oh, yes,” she said cheerfully. “We’re overrun with them. No more beds at all. They’re putting them in Emergency now. That’ll be full soon, I’ll warrant. You’ve got a private room, but you should hear them moanin’ and groanin’ in Ward E. Sixty beds, they’ve got in there. All this funny food thing, like you. Though mostly worse cases. Like I said, you’re one of the lucky ones. Now, time to get some food into you.”

“Food?” he said in horror. The memory of his last dinner with Laura engulfed him in nausea. “Nurse!”

“Going to upchuck, are you?” She sounded as cheerful as ever. Deftly she fitted a kidney-shaped basin under his chin and supported his head. He retched miserably. Greenish slime trailed down his chin and left a bitter taste in his mouth. His stomach hurt like hell.

“Nothing in you, see. Just lie still now and don’t go getting excited again.”

“You said food,” he rasped accusingly.

She laughed merrily. “Well, so I did, but I didn’t mean food . Time to change your IV bottle, that’s all.”

He closed his eyes again. His head throbbed. He heard her bustling around. Presently the door closed. Distantly, through double windows, he heard the hum of London’s traffic. Where was he, anyway? Guy’s Hospital, perhaps? He remembered more clearly now. It had come on him very suddenly. He had felt fine going home. He had waked after an hour’s sleep, feeling vaguely nauseated, and had got out of bed. The clenching paralysis seized him after a few steps. He remembered lying curled on the bedroom floor, unable to call out, hardly daring to breathe. Sarah, of course, was out. He supposed he might have died if it had been the housekeeper’s night off, too.

When he woke, he felt more lucid. His head pulsed with a slow ache. He rang for the nurse. It was a different one, an Indian girl this time. He knew he was better when he found himself trying to gauge the size of her breasts under the starched uniform.

“How are you feeling now, Mr. Peterson?” she asked in a sing-song voice, bending over him.

“Better. What time is it?”

“It’s half-past five now.”

“I’d like my watch back. And I’m hungry. I could manage something very light.”

“I’ll see what’s allowed,” she said and left the room silently.

He struggled into a sitting position. The nurse trotted in again with a radio and a note.

“You had a visitor, Mr. Peterson,” she said, smiling. “She wouldn’t stay, but she left this. And you can have some broth. It’ll be up presently.”

He recognized Sarah’s large graceful loops and flourishes on the envelope and opened the note.

Ian—What a terrible bore for you: Can’t stand hospitals so I won’t visit, but I thought you could use this radio. I’m leaving for Cannes Friday. Hope to see you before then. If not, give me a ring. I’ll probably be home. Wednesday evening. Bye bye. Sarah .