The Time Surgeons

Baronak began to work feverishly.

The equations were difficult, the lines of thought they opened tantalizing in their hints but reluctant to give up their full secrets.

For a little over a month he worked on the problem alone, chasing his vision down paths of higher mathematics only he could see, wondering if any of it was real.

Occasionally Jennara would visit him, bearing gifts of food and morsels of conversation. Sometimes she would find him stretched out in an exhausted sleep, and she would cover him as he had done for her that first morning, before silently slipping out. Sometimes she would see his eyes burning with excitement, and their lovemaking would seem to burn like the Fury itself. But other times his eyes were haunted, and those times were increasing. She wondered why, but when she asked he would not say.

Finally one day he sat before his computer, looking at what he had found. It looked terrible, but right. But is it real, or have I created a mirage?

There were many experimental facilities. Baronak did some calculations, then the next day he modified one of the experimental rigs according to his findings and set its target. There were dangers he dared not risk yet, not when he still knew so little. So he would not be able to see his results. He did not have to: his instruments would tell him the truth.

He turned on the machine, tuned the great energies that twisted spacetime, and in the center of his apparatus a small point of light appeared. He looked at the readouts of its detectors then applied more energy. The point of light grew to an impossible blackness surrounded by a circlet of auroral light, about a quarter of his finger’s diameter. He counted: one, two, three.. ten heartbeats. The circle was still there. He dialed back the system and turned it off, and the circle vanished.

He resumed breathing.

He pored over the data from the sensor array, comparing it to his equations. He repeated his experiment with some variations, again being careful to avoid the most obvious dangers.

A week later he went to see Pachmeny and Arragath.

“My son,” greeted Pachmeny, holding out her hand to him.

“Mother, Father,” said Baronak, bowing then kissing their foreheads.

They had aged beyond their time, his beloved parents. Both were still bright of eye and keen of mind, but the toll of years had worn them down. Whether it was the stress of their task, the unavoidable toxins in their closed environment, the higher radiation they suffered, or old damage from the Fury, their bodily systems were degrading faster than they should have. And now perhaps I can save us. But at what cost?

“You look exhausted, dear Baronak. Are you eating enough?”

“You no longer need to nag me, Mother,” he replied with a smile. “I have gained a friend, Jennara, who has made it her mission to ensure I eat and sleep occasionally. The nagging is in good hands.”

“I am happy for you, son. But you said you had found something important, Baronak? It is sweet of you to come to us with it, but you know that you have long surpassed us in the science of Einstein.”

“Your thoughts are always valuable. But it is more than that. What I have found is dangerous. Extremely dangerous. If our straits were not so dire, I would probably run from it, not carry it to you.”

Pachmeny and Arragath glanced at each other. Dilemmas like that were no stranger to them.

“Speak, beloved son. We are always here for you.”

“To build a burrow is possible. That we already knew. To build a burrow through spacetime to a distant place, large enough to be useful and persistent enough to complete the journey, is impossible.”

He saw the fading of light in his parents’ eyes, but the residue of hope remaining: for they knew he would not tell them this if it was all there was to tell.

“It is impossible because it requires negative energy. For all the advances we have made, understanding its nature and harnessing its power is far beyond us, if it exists at all. We have come this far by grace of the effort, lies and sacrifices you know more than any. But we can go no further. Perhaps one day it will be possible for people to understand it and walk to the stars. But we have exhausted our power. Our world is dying, and we lack the strength to reach our goal. We are finished. We are out of time. We may have decades left to us but no more. Even decades are not enough when each year erodes our power.”

He looked at them for a few moments in silence.

“But there is another way to look at the equations. I cannot find a way to burrow to a distant space, but I have found a way to burrow to a distant time.”

His parents gasped. “You mean… time travel? Back in time? How? How can you do that without violating causality? Surely to travel back in time, and act in your past, is to destroy your own present?”

“Now you see why I came to you with this.”

“Tell us all.”

“We need negative energy to build a useful burrow across vast distances of space, and we have no idea how to do it. But the very paradoxes of travelling back through time provide their own solution. Burrowing back through time in itself produces something mathematically akin to negative energy. A burrow through time produces its own reinforcement, as it were. The length and size of the burrow are no longer limiting over spans of tens of thousands of years.”

“And beyond that?”

“It is a curve, not really a bell-shaped curve but something similar. Too short a time and there is too little negative energy equivalence for a useful burrow. A day is too short. For a week, we should be able to achieve a small burrow with a limited life. Too long a time and the potential causality violations begin to overwhelm the effect, and the burrows become increasingly unstable again. Between those extremes, the further back you go and the wider the burrow the more energy you need to open and maintain it, but it remains stable long enough to be useful.”

Pachmeny and Arragath stared at him, trying to absorb the enormity of what he was saying. Finally Arragath spoke.

“But the Earth moves through space, both around the Sun and carried by the Sun and Galaxy through the vastness of the cosmos. If we can burrow through time but not space, what is the purpose? The burrow would open into the vacuum of empty space.”

“Space is not absolute: space, time, matter and gravity are intertwined. The tunnel is anchored in the Earth’s gravity well. The further back in time we go, the more we can wander from our geographic point of origin, but as far back as the Death of the Ancients itself, no more than around the surface of the globe and a few thousand feet in elevation.”

“But that itself increases the causality problem we started with,” objected Pachmeny. “If the burrows ended up far away the potential for causality violation would be almost eliminated. But going back into Earth’s own past? How can you do that without violating causality? What stops you doing something that will alter the future to stop you doing it, creating a time paradox?”

“That isn’t a problem on small scales. While some have speculated that the time invariance of quantum equations means causality is an illusion, in fact it is the opposite. The wave equations repair themselves, like a rubber band returning to its original form after being distorted. You could say that reality and causality ‘snap back’ around any quantum-level breach caused by our burrow.”

“How far can we push that?”

“I do not yet know. But my preliminary calculations are that we can view the past safely. That is not surprising when we already know viewing the past is inherent in the finite speed of light, and brings with it no genuine paradoxes.”

“But this is different, surely? To observe the past through a burrow, are you not stealing information and radiation from that past, so that whatever it would have hit is no longer hit, thus changing history?”

“It is the rubber band again. The effects of absorbing energy, provided we minimize them so they are small compared to the wash of quantum events they are embedded in, do not affect the future. We cannot actually steal radiation from the past, but if we absorb it, it is replaced by random, incoherent radiation from our present. Thus we absorb information from the past while transmitting none from the future; while the net energy in both is conserved.”

“If that is true, what good does it do? It sounds like you can do some fiddling at the quantum level, but whatever effect you caused will not persist. So you couldn’t even send information, let alone objects.”

“My equations indicate that we can send macroscopic objects back through time. But they will last only so long as they do not cause effects which cannot be snapped back by compensating distortions in the quantum wave functions. In other words, when reality is inexorably set on a new course they will cease to exist. In a sense they never existed. Also there is a time limit. The equations are too complex for more than an approximation at this stage, but I estimate that the maximum persistence is about half an hour, and certainly no more than an hour. Their very presence affects things and the causality tensions steadily build up; again, the object will cease to exist because it never existed, or was never sent back.”

“But how does that preserve causality? If the object changes history so it never existed, how did it exist to change history? We are back to an insoluble paradox.”

“I have been thinking about this. Let me lead you along the path I have travelled.

“We know that light is a wave, but where its photons are absorbed is random. Those photons are not particles, though mathematically we can treat them as such for many purposes of calculation. Their reality is that only quanta of light energy can be absorbed or emitted, so any such absorption or emission must become localized to the point where it occurs. The light energy itself spreads through spacetime as a wave until and unless it is absorbed.”

He looked at his parents, who nodded their understanding.

“Now consider a wave equation, looking forward in time. All outcomes are possible: we can only predict what might happen as a matter of probability. The possible and probable do not become actual until they occur. Mathematically the wave function collapses, much as the wave itself collapses. Until then we could say that all possibilities exist in a virtual future, until the future becomes the present and then the past.”

He glanced up and his parents nodded again, albeit less certainly now.

“What happens if we travel back in time is not a causality paradox, but a causality loop. If you were a god standing astride eternal spacetime looking at the structure of reality, you would see a loop from a virtual future curving back to change the course of history, so that what was once a virtual future now becomes reality, while the former reality becomes virtual. What that actually means is beyond my comprehension. But that is what the equations tell me.”

His parents looked at him in stunned silence. Finally Pachmeny spoke again.

“I will not insult your intelligence by telling you this is impossible, much as I would like to. But how sure are you of all this? One can see many things in equations, only to find that some factor you haven’t taken into consideration prevents their reality. Just as we found with our theoretical hopes of burrowing through lightyears of space.”

“I know, because I have done it.”

The room was silent for long seconds. Finally Pachmeny said softly, “You risked a causality violation?”

“I figured that if nature allowed it, it would be allowed, and the worst that could happen was failure. But I was careful. I sent my burrow two years into our past, long enough for modest stability of a tiny burrow but short enough to minimize any changes to the timeline, and to a time when I knew nobody would be in the laboratory to see it – since nobody did.

“But I did it. The sensor results confirm that it went back in time; and the stability and size of the burrows I could maintain matched the equations.

“And that is why I am here. That was as much as I dared do on my own. But to do anything useful I need to do more. Much more. At the risk of snuffing out our own existence. I could not make that decision alone.”

“But again: what justifies the risk? From what you say we can’t use this to escape into the past, for we would vanish before the day ended.”

She stopped with a gasp. “Or are you saying we can escape into the future, to some point thousands of years from now when life may again have covered the Earth above?!”

He shook his head. “That is what I hoped. But it doesn’t work. The burrow needs to go back through time in order for the negative energy to hold it stable. Going forward produces no such tension and cannot be done. At least, if it can be done the answer is not in my equations.”

“So you have discovered something amazing, but it does not help us? We can neither go sideways through space relative to Earth, for the burrows cannot be built; nor forward through time, for the same reason; nor backward into the past, for the release of causality paradox would destroy us soon after we arrived?”

“No, it does not help… us,” he replied slowly.

“What… what do you mean?” asked Pachmeny softly.

“Imagine if what we have achieved today had been achieved hundreds of years ago? Or thousands? And they knew what was to come? Centuries more for the combined intellect and resources of a world to study the problem? It would give the world a chance: a chance to find the route to the stars. A chance to escape the fate of our world.”

“But…”

“But. We would cease to be. I would never have been born. You would never have been born. Nobody in our past from soon after the resetting of history would have been born.

“It is a death sentence for you, me, for everyone we have ever known and ever loved. A death sentence for billions, stretching over thousands of years.

“We seek to save the world. But to do so, we must destroy our own past and our own present.”

Pachmeny knew her son, knew what lay in his eyes. “And still there is more, isn’t there?”

He nodded. “Yes. We have one shot. One shot only. Once we do this we cease to exist. If we fail to buy the world time it is all for nothing. Perhaps those who replace us will do a better job. But there is only one thing we know: we know an answer. We do not know that those others will find it. I was lucky to find it myself. We can decide not to do this and hope we find a better answer before the end. But if we decide to do it we must choose carefully. We must get it right the first time, for that is our only time. Or we will have destroyed our world as well as ourselves, and possibly any chance for our whole race.”