"Greg Egan - Border Guards" - читать интересную книгу автора (Egan Greg)

Border Guards
by Greg Egan
In the early afternoon of his fourth day out of sadness, Jamil was wandering home from the gardens at the
centre of Noether when he heard shouts from the playing field behind the library. On the spur of the
moment, without even asking the city what game was in progress, he decided to join in.
As he rounded the corner and the field came into view, it was clear from the movements of the players
that they were in the middle of a quantum soccer match. At Jamil's request, the city painted the wave
function of the hypothetical ball across his vision, and tweaked him to recognise the players as the
members of two teams without changing their appearance at all. Maria had once told him that she always
chose a literal perception of colour-coded clothing instead; she had no desire to use pathways that had
evolved for the sake of sorting people into those you defended and those you slaughtered. But almost
everything that had been bequeathed to them was stained with blood, and to Jamil it seemed a far
sweeter victory to adapt the worst relics to his own ends than to discard them as irretrievably tainted.

The wave function appeared as a vivid auroral light, a quicksilver plasma bright enough to be distinct in
the afternoon sunlight, yet unable to dazzle the eye or conceal the players running through it. Bands of
colour representing the complex phase of the wave swept across the field, parting to wash over separate
rising lobes of probability before hitting the boundary and bouncing back again, inverted. The match was
being played by the oldest, simplest rules: semi-classical, non-relativistic. The ball was confined to the
field by an infinitely high barrier, so there was no question of it tunnelling out, leaking away as the match
progressed. The players were treated classically: their movements pumped energy into the wave, enabling
transitions from the game's opening state — with the ball spread thinly across the entire field — into the
range of higher-energy modes needed to localise it. But localisation was fleeting; there was no point
forming a nice sharp wave packet in the middle of the field in the hope of kicking it around like a classical
object. You had to shape the wave in such a way that all of its modes — cycling at different frequencies,
travelling with different velocities — would come into phase with each other, for a fraction of a second,
within the goal itself. Achieving that was a matter of energy levels, and timing.

Jamil had noticed that one team was under-strength. The umpire would be skewing the field's potential
to keep the match fair, but a new participant would be especially welcome for the sake of restoring
symmetry. He watched the faces of the players, most of them old friends. They were frowning with
concentration, but breaking now and then into smiles of delight at their small successes, or their
opponents' ingenuity.

He was badly out of practice, but if he turned out to be dead weight he could always withdraw. And if
he misjudged his skills, and lost the match with his incompetence? No one would care. The score was nil
all; he could wait for a goal, but that might be an hour or more in coming. Jamil communed with the
umpire, and discovered that the players had decided in advance to allow new entries at any time.

Before he could change his mind, he announced himself. The wave froze, and he ran on to the field.
People nodded greetings, mostly making no fuss, though Ezequiel shouted, “Welcome back!” Jamil
suddenly felt fragile again; though he'd ended his long seclusion four days before, it was well within his
power, still, to be dismayed by everything the game would involve. His recovery felt like a finely balanced
optical illusion, a figure and ground that could change roles in an instant, a solid cube that could evert into
a hollow.

The umpire guided him to his allotted starting position, opposite a woman he hadn't seen before. He
offered her a formal bow, and she returned the gesture. This was no time for introductions, but he asked
the city if she'd published a name. She had: Margit.