The Light of Other Days. Stephen Baxter

wash. He could ‘pick up’ documents and models with a fingertip, rummaging until he found what he wanted, exactly where he'd left it last time.

      First he had to check for detector pixel faults. He began passing the vertex detector traces into the analogue signal bus, and pulled out a blow-up overview of various detector slabs. There were always random failures of pixels when some especially powerful particle hit a detector element. But, though some of the detectors had suffered enough radiation damage to require replacement, there was nothing serious for now.

      Humming, immersed in the work, he prepared to move on –

      ‘Your user interface is a mess.’

      David, startled, turned. Bobby was still here: still leaning, in fact, against his table.

      ‘Sorry,’ David said. ‘I didn't mean to turn my back.’ How odd that he hadn't even noticed his brother's continued presence.

      Bobby said now, ‘Most people use the Search Engine.’

      ‘Which is irritatingly slow, prone to misunderstanding and which anyhow masks a Victorian-era hierarchical data storage system. Filing cabinets. Bobby, I'm too dumb for the Search Engine. I'm just an unevolved ape who likes to use his hands and eyes to find things. This may look a mess, but I know exactly where everything is.’

      ‘But still, you could study this particle-track stuff a lot better as a virtual. Let me set up a trial of my latest Mind'sEye prototype for you. We can reach more areas of the brain, switch more quickly –’

      ‘And all without the need for trepanning.’

      Bobby smiled.

      ‘All right,’ David said. ‘I'd appreciate that.’

      Bobby's gaze roamed around the room in that absent, disconcerting way of his. ‘Is it true? What you told dad – that this isn't a failure, but just another step?’

      ‘I can understand Hiram's impatience. After all he's paying for all of this.’

      ‘And he's working under commercial pressure,’ Bobby said. ‘Already some of his competitors are claiming to have DataPipes of comparable quality to Hiram's. It surely won't be long before one of them comes up with the idea of a remote viewer – independently, if nobody's leaked it already.’

      ‘But commercial pressure is irrelevant,’ David said testily. ‘A study like this has to proceed at its own pace. Bobby, I don't know how much you know about physics.’

      ‘Assume nothing. Once you have a wormhole, what's so difficult about expanding it?’

      ‘It's not as if we're building a bigger and better car. We're trying to push spacetime into a form it wouldn't naturally adopt. Look – wormholes are intrinsically unstable. You know that to keep them open at all we have to thread them with exotic matter.’

      ‘Antigravity.’

      ‘Yes. But the tension in the throat of a wormhole is gigantic. We're constantly balancing one huge pressure against another.’ David balled his fists and pressed them against each other, hard. ‘As long as they are balanced, fine. But the smallest perturbation and you lose everything.’ He let one fist slide over the other, breaking the equilibrium he'd established. ‘And that fundamental instability grows worse with size. What we're attempting is to monitor conditions inside the wormhole, and adjust the pumping of exotic matterenergy to compensate for fluctuations.’ He pressed his fists against each other again; this time, as he jiggled the left back and forth, he compensated with movements of his right, so his knuckles stayed pressed together.

      ‘I get it,’ Bobby said. ‘As if you're threading the wormhole with software.’

      ‘Or with a smart worm.’ David smiled. ‘Yes. It's very processor-intensive. And so far, the instabilities have been too rapid and catastrophic to deal with.

      ‘Look at this.’ He reached to his desktop and, with the touch of a fingertip, he pulled up a fresh view of a particle cascade. It had a strong purple trunk – the colour showing heavy ionization – with clusters of red jets, wide and narrow, some straight, others curved. He tapped a key, and the spray rotated in three dimensions; the software suppressed foreground elements to allow details of the jet's inner structure to become visible. The central spray was surrounded by numbers showing energy, momentum and charge readings. ‘We're looking at a high-energy, complex event here, Bobby. All this exotic garbage spews out before the wormhole disappears completely.’ He sighed. ‘It's like trying to figure out how to fix a car by blowing it up and combing through the debris.

      ‘Bobby, I was honest with father. Every trial is an exploration of another corner of what we call parameter space, as we try different ways of making our wormhole viewers wide and stable. There are no wasted trials; every time we proceed we learn something. In fact many of my tests are negative – I actually design them to fail. A single test which proves some piece of theory wrong is more valuable than a hundred tests showing that idea might be true. Eventually we'll get there…or else we'll prove Hiram's dream is impossible, with present-day technology.’

      ‘Science demands patience.’

      David smiled. ‘Yes. It always has. But for some it is hard to remain patient, in the face of the black meteor which approaches us all.’

      ‘The Wormwood? But that's centuries off.’

      ‘But scientists are hardly alone in being affected by the knowledge of its existence. There is an impulse to hurry, to gather as much data and formulate new theories, to learn as much as possible in the time that is left – because we no longer are sure there will be anybody to build on our work, as we've always assumed in the past. And so people take short-cuts, the peer review process is under pressure…’

      Now a red alert light started flashing high on the counting house wall, and technicians began to drift back into the room.

      Bobby looked at David quizzically. ‘You're setting up to run again? You told dad you only ran one trial a day.’

      David winked. ‘A little white lie. I find it useful to have a way to get rid of him.’

      Bobby laughed.

      It turned out there was time to fetch coffee before the new run began. They walked together to the cafeteria.

      Bobby is lingering, David thought. As if he wants to be involved. He sensed a need here, a need he didn't understand – perhaps even envy. Was that possible?

      It was a wickedly delicious thought. Perhaps Bobby Patterson, fabulously rich, this latter-day dandy, envies me – his earnest, drone-like brother.

      Or perhaps that's just sibling rivalry on my part.

      Walking back, he sought to make conversation.

      ‘So. Were you a grad student, Bobby?’

      ‘Sure. But at HBS.’

      ‘HBS? Oh. Harvard –’

      ‘Business School. Yes.’

      ‘I took some business studies as part of my first degree,’ David said. He grimaced. ‘The courses were intended to “equip us for the modern world”. All those two-by-two matrices, the fads for this theory or that, for one management guru or another…’

      ‘Well, business analysis isn't rocket science, as we used to say,’ Bobby murmured evenly. ‘But nobody at Harvard was a dummy. I won my place there on merit. And the competition there was ferocious.’

      ‘I'm sure it was.’ David was puzzled by Bobby's flat tone of voice, his lack of fire. He probed gently. ‘I have the impression you feel – underestimated.’

      Bobby shrugged. ‘Perhaps. The VR division of OurWorld is a billion-buck business in its own right. If I fail, dad's made it clear he's not going to bail me out. But even Kate thinks I'm some kind of placeholder.’ Bobby grinned. ‘I'm enjoying trying to convince her otherwise.’

      David frowned.