Bridging Infinity

by Jonathan Strahan

  One morning she comes into my office. She had to share one with three postdocs herself, so she envied me having a whole office to myself. I think she’s come to talk about training, but instead Kuroshio drops a handkerchief-sized scrap of paper onto my desk, like it’s a gift, and invites me to examine the contents. Is any of this making sense to you?

  Never mind. All I can see is a tiny sliver of metal, a sort of dirty silver in colour. I ask Kuroshio to explain and she says it’s a sample of a new alloy, a blend of hafnium, carbon and nitrogen, cooked up in the solid-state physics lab. Like I’m supposed to be impressed. But actually I am, once she starts giving me the background. This is a theoretical material: a substance dreamed up in a computer before anyone worked out how to synthesize it. And the startling thing is, this material could endure two thirds of the surface temperature of the Sun without melting.

  “You know what this means, don’t you?” she asked me. “This is only a beginning. We can think about reaching that crazy alien thing you discovered. We can think about drilling a shaft into the Sun.”

  I laughed at her, but I really shouldn’t have.

  Kuroshio was right.

  What makes you think you might be a suitable candidate for doctoral work? Select one or more answers from the options below. Leave blank if you feel none of the options apply.

  O I am a diligent student. I have studied hard for my degree and always completed my coursework on time.

  O I believe that I have a capacity for independent research. I do not need constant supervision or direction to guide my activities. In fact, I work better alone than in a crowd.

  O I look forward to the day when I can call myself “doctor”. I will enjoy the prestige that comes from the title.

  You felt that the solar heliospheric oscillations would be a fruitful area to explore?

  No, an inward voice answers sarcastically. I thought that it would be an excellent way to waste three years. But she straightens in her chair and tries to make her hands stop wrestling with each other. It’s sweaty and close in this too-small office. The blinds are drawn, but not perfectly, and sunlight is fighting its way through the gaps. Bars of light illuminate dust in the air, dead flies on the windowsill, the spines of textbooks on the wall behind the main desk.

  “Before I left Mumbai I’d spent a summer working with Sun Dragon, a graphics house working on really tough rendering problems. Light-tracing, real physics, for shoot ’em up games and superhero movies. I took one look at what those guys were already doing, compared it to the models everyone else was using to simulate the solar oscillations, and realised that the graphics stuff was way ahead. So that’s where I knew I had an edge, because I’d soaked up all that knowledge and no one in astrophysics had a clue how far behind they were. That gave me a huge head start. I still had to build my simulation, of course, and gather the data, and it was a whole year before I was even close to testing the simulation against observations. Then there was a lot of fine-tuning, debugging...”

  They look at graphs and tables, chewing over numbers and interpretation. The coloured images of the solar models are very beautiful, with their oddly geometric oscillation modes, like carpets or tapestries wrapped around the Sun.

  “P-mode oscillations are the dominant terms,” she says, meaning the pressure waves. “G-mode oscillations show up in the models, but they’re not nearly as significant.”

  P for pressure.

  G for gravity.

  The road to Prometheus Station was arduous. Few of us have direct memories of those early days. But the prolongation has given you an unusual, not to say unique perspective. Do you remember the difficulties?

  Difficulty was all we knew. We breathed it like air. Every step was monumental. New materials, new cooling methods, each increment bringing us closer and closer to the photosphere. Our probes skimmed and hovered, dancing closer to that blazing edge. They endured for hours, minutes. Sometimes seconds. But we pushed closer. Decades of constant endeavour. A century gone, then another. Finally the first fixed bridgehead, the first physical outpost on the surface of the Sun. Prometheus Station. A continent-sized raft of black water lilies, floating on a breath of plasma, riding the surge and plunge of cellular convection patterns. Not even a speck on the face of the Sun, but a start, a promise. The lilies existed only to support each other, most of their physical structure dedicated to cooling – threaded with refrigeration channels, pumps as fierce as rocket engines, great vanes and grids turned to space... each a floating machine the size of a city, and we had to keep building the entire network and throwing it away, whenever there was a storm, a mass ejection, or a granulation supercell too big for our engineering to ride out. We got better at everything, slowly. Learned to read the solar weather, to adjust Prometheus Station’s position, dancing around the prominences. Decades and decades of failure and frustration, until we managed to survive two complete turns of the sunspot cycle. Slowly the outpost’s complexity increased. To begin with, the only thing we required of it was to endure. That was challenge enough! Then we began to add functionality. Instruments, probes. We drilled down from its underside, pushed feelers into thickening plasma. Down a hundred kilometres, then a thousand. No thought of people ever living on it – that was still considered absurd.

  The alignment between your models and the p-mode data is impressive – groundbreaking. It will be of great benefit to those working to gain a better understanding of the energy transport mechanisms inside the Sun. Indeed, you go further than that, speculating that a thorough program of modelling and mapping, extended to a real-time project, could give us vital advance warning of adverse solar weather effects, by linking emergent patterns in the deep convection layers with magnetic reconnection and mass ejection episodes. That seems a bold statement for a doctoral candidate. Do you wish to qualify it?

  No.

  But people came, didn’t they? Or what we might call people?

  Call them what you will. All I know is that we’d got better at stability. Fifty years without losing Prometheus Station, then a century. I’d have lived to see none of it if they hadn’t offered me the prolongation, but by then I was too vital to the project to be allowed the kindness of dying. And I’m not sorry, really, at least not of those early stages. It was marvellous, what we learned to do. I wish Kuroshio had seen it all – I wish they’d been as generous to her as they were to me. I wish she’d been there when the machines constructed a station, a habitable volume on one of the central lilies. Heat wasn’t the central problem by then – we could cool any arbitrary part of the station down as low as we liked, provided we accepted a thermal spike elsewhere. Thermodynamics, that’s all. Gravity turned out to be the real enemy. Twenty seven gees! No unaugmented person could survive such a thing for more than a few seconds. So they shaped the first occupants. Rebuilt their bodies, their bones and muscles, their circulatory systems. They were slow, lumbering creatures – more like trees or elephants than people. But they could live on the Sun, and to the Sunwalkers it was the rest of us who were strange, ephemeral, easily broken. Pitiable, if you want the truth of it. Of course, I had to become one of them. I don’t remember who had the idea first, me or them, but I embraced the transformation like a second birth. They sucked out my soul and poured it back into a better, stronger body. Gave me eyes that could stare into the photosphere without blinking – eyes that could discriminate heat and density and patterns of magnetic force. We strode that bright new world like gods. It’s exactly what we were, for a little time. It was glorious.

  No, better than that. We were glorious.

  Let’s turn now to your concluding remarks. You summarise your mathematical principles underpinning your simulations, discuss the complexities involved in comparing the computer model to the observed p-mode data, and highlight the excellent agreement seen across all the comparisons. Or almost all of them. What are we to make of the discrepancies, slight as they are?

  “They’re just residuals,” she says, not wanting to be drawn
on this point, but also not wanting to make it too obvious that she would rather be moving into safer waters. The Sun’s angle behind the blinds has shifted during the conversation and now a spike of brightness is hitting her dead in the eye, making her squint. There’s a migraine pressure swelling up somewhere behind her forehead.

  “The worrying thing would be if the model and the data were in too close an agreement, because then you’d conclude that one or the other had been fudged.” She squints at them expectantly, hoping for the agreement that never comes. “Besides, the only way to resolve that discrepancy – small as it is – would be to introduce an unrealistic assumption.”

  What attracts you to the idea of working in Tokyo? Select one or more answers from the options below. Leave blank if you feel none of the options apply.

  O Tokyo is a bustling city with vibrant nightlife. I plan to throw myself into it with abandon. I will never be short of things to do in Tokyo.

  O I have always had a romantic attachment to the idea of living in Japan. I have seen many films and read many comic strips. I am certain that I will not be disappointed by the reality of life in Tokyo.

  O Beyond the university, the city is irrelevant to me. Provided I have somewhere affordable to sleep, and access to colleagues, funds and research equipment, I could live anywhere. I expect to spend most of my time in air-conditioned rooms, staring at computer screens. I could be in Mumbai or Pasadena or Cairo for all the difference it will make.

  But to go deeper... you must have quailed at the challenge ahead of you?

  We did, but we also knew no one was better equipped to face it. Slowly we extended our downward reach. Ten thousand kilometres, eventually – feelers tipped with little bubbles of air and cold, in which we could survive. The deep photosphere pressing in like a vice made of light, seeking out the tiniest flaw, the slightest weakness. Beneath three hundred kilometres, you couldn’t see the sky any more. Just that furious white furnace, above and below.

  But clever alloys and cooling systems had taken us as far as they were capable. Electron-degenerate matter was our next advance – the same material white dwarf stars are made out of. A century before we got anywhere with that. Hard enough to crush matter down to the necessary densities; even harder to coax it into some sort of stability. Only the fact of the Anomaly kept us going. It provided a sort of existence theorem for our enterprise. An alien machine survives inside the Sun, deeper than any layer we’ve reached. If it can do that, so can we.

  Hubris? Perhaps.

  But the truth is we might as well have been starting science from scratch. It was like reinventing fire, reinventing basic metallurgy.

  We did it, all the same. We sent sounding probes ahead of the main shaft, self-contained machines constructed from shells of sacrificial degenerate matter. Layers of themselves boiled away until all that was left was a hard nugget of cognitive machinery, with just enough processing power to swim around, make observations and signal back to us. They forged a path, tested our new materials and methods. Another century. We pushed our physical presence down to thirty thousand kilometres – a borehole drilled half way to the prize. Conditions were tough – fully murderous. We could send machines to the bottom of the shaft, but not Sunwalkers. So we shaped new explorers, discarding our old attachment to arms and legs, heads and hearts. Sunsprites. Sun Dragons, I called us. A brain, a nervous system, and then nothing else you’d ever recognise as human. Quick, strong, luminous creatures – mermaids of light and fire. I became one, when they asked. There was never the slightest hesitation. I revelled in what they’d made of me. We could swim beyond the shaft, for a little while – layers of sacrificial armour flaking away from us like old skins. But even the degenerate matter was only a step along the way. Our keenest minds were already anticipating the next phase, when we had to learn the brutal alchemy of nuclear degenerate matter. Another two centuries! Creating tools and materials from neutron-star material made our games with white dwarf matter look like child’s play. Which it was, from our perspective. We’d come a long way. Too far, some said.

  But still we kept going. What else were we going to do?

  What do you mean by unrealistic?

  “Look,” she says, really feeling that migraine pressure now, her squinting eyes watering at the striped brightness coming through the blinds, a brightness with her name on it. “Everyone knows the Sun is round. A child will tell you that. Your flag says the same thing. But actually the Sun is really quite unreasonably round. It’s so round that it’s practically impossible to measure any difference between the diameter at the poles and the diameter at the equator. And if a thing’s round on the outside, that’s a fairly large hint that it’s symmetric all the way through to the middle. You could explain away the residuals by adding an asymmetric term into the solar interior, but it really wouldn’t make any sense to do so.”

  And nor, she thinks, would it make sense to introduce that term anyway, then run many simulations springing from it, then compare them against the data, over and over, hoping that the complication – like the cherry blossoms – will fall away at the first strong breeze, a transient business, soon to be forgotten.

  They stare at her with a sort of polite anticipation, as if there is something more she ought to have said, something that would clear the air and allow them to proceed. They are concerned for her, she thinks – or at least puzzled. Her gaze slips past theirs, drawn to the pattern behind the blinds, the play of dust and light and shadow, as if there’s some encouraging or discouraging signal buried in that information, hers for the reading.

  But instead they ask to see a graph of the residuals.

  Can you be certain of our fate?

  Yes, as I’m sure of it as anyone can be. Obviously there are difficulties of translation. After all the centuries, after all the adaptive changes wrought on me, my mind is very far from that of a baseline human. Having said that, I am still much, much closer to you than I am to the Anomaly. And no matter what you may make of me – no matter how strange you now find me, this being that can swim inside a star, this Sun Dragon of degenerate matter who could crush your ships and stations as easily as she blinks, you must know that I feel a kinship.

  I am still human. I am still Kamala Chatterjee, and I remember what I once used to be. I remember Mumbai, I remember my parents, I remember their kindness in helping me follow my education. I remember grazing my shins in football. I remember the burn of grass on my palm. I remember sun-dappled paths, paper lanterns and evening airs. I remember Kuroshio, although you do not. And I call myself one of you, and hope that my account of things is accurate. And if I am correct – and I have no reason to think otherwise – then I am afraid there is very little ambiguity about our fate.

  When I touched the Anomaly, I suddenly knew its purpose. It’s been waiting for us, primed to respond. Sitting inside the Sun like a bomb. An alien timebomb. Oh, you needn’t worry about that. The Sun won’t explode, and tongues of fire won’t lash out against Earth and the other worlds. Nothing so melodramatic.

  No; what will happen – what is happening – is far subtler. Kinder, you might say. You and I live in the moment. We have come to this point in our history, encountered the Anomaly, and now we ponder the consequences of that event. But the Anomaly’s perception isn’t like that. Its view of us is atemporal. We’re more like a family tree than a species. It sees us as a decision-branch structure frozen in time – a set of histories, radiating out from critical points. An entity that has grown into a particular complex shape, interacted with the Anomaly across multiple contact points, and which must now be pruned. Cut back. Stripped of its petals as the summer winds strip a cherry blossom.

  I can feel it happening. I think some of it rubbed off on me, and now I’m a little bit spread out, a little bit smeared, across some of these histories, some of these branches. Becoming atemporal. And I can feel those branches growing thinner, withering back from their point of contact, as if they’ve touched a poison. Can you feel it too?
/>
  No, I didn’t think so.

  If you were offered a placement, when do you think you would be able to start your research? Select one or more answers from the options below. Leave blank if you feel none of the options apply.

  O I would be able to start within a few months, once I have settled my affairs in my home country.

  O I would like to start immediately. I am eager to begin my doctoral work.

  O I would like time to consider the offer.

  We feel that the thesis cannot be considered complete without a thorough treatment of the residual terms. A proper characterisation of these terms will lead to a clearer picture of the “anomaly” that seems to be implied by the current analysis. This will entail several more months of work. Are you prepared to accept this commitment?

  A moment grows longer, becomes awkward in its attenuation. She feels their eyes on her, willing her to break the silence. But it has already gone on long enough. There can be no way to speak now that will not cast a strange, eccentric light on her behaviour. That light coming through the window feels unbearably full of meaning, demanding total commitment to the act of observation.