Resa

"A computer", Calvin said, finishing the sentence for him. "That's what Hades is. A computer made out of nuclear matter, the mas of a star devoted to processing information, storing it. And this light is an aperture into it; a way to enter the computational matrix. I think for a moment we were actually in it".

But it was much stranger than that.

Once, a star with a mass thirty or forty times heavier than Earth's sun had reached the end of its nuclear-burning lifetime. After several million years of profligate energy-expenditure. The star had exploded as a supernova, and in its heart , tremendous gravitational pressure had smashed a lump of matter within its own Schwarzschild radius, until a black hole had been formed. The black hole was so named because nothing, not even light, could escape from its critical radius, Matter and light could only fall into the black hole, thereby engorging it towards greater mass and greater attractive force; a vicious circle.

A culture arose that had use for such an object. They knew a technique whereby a black hole could be transformed into something far more exotic, far more paradoxical. First, they waited until the universe was considerably older than when the black hole had been formed; until the predominant stellar population consisted of very old red-dwarf stars, stars which were barely massive enough to ignite their own fusion fires. Next, they shepherded a dozen of these dwarves into an accretion disk around the black hole and slowly allowed the disc to feed the hole, raining starstuff onto its light-swallowing event horizon.

This much Sylvestre understood, or could at least deceive himself into thinking that he understood. But the next part -the core of it- was much harder to hold in his mind, like a self-contradictory koan. What he grasped was that, once within the event horizon, particles continued to fall along particular trajectories, particular orbits which swung them around the kernel of infinite density which was the singularity at the black hole's heart. Falling along these lines, time and space began to blend into one another, until they were no longer propely separable. And -crucially- there was one set of trajectories in which they swapped places completely; where a trajectory in space became one in time. And one subset of this bunch of paths actually allowed matter to tunnel into the past, earlier into the black hole's history.

"I'm accessing texts from the twentieth century", Calvin murmured, seemingly able to follow his thoughts. "This effect was known -predicted- even then. It seemed to follow from the mathematics describing black holes. But no one knew how seriously to take it".

"Whoever engineered Hades had no such qualms".

"So it would seem".

What happened was that light, energy, particle-flux, wormed along these special trajectories, burrowing ever deeper into the past with each orbit around the singularity. None of this was "evident" to the outside universe since it was confined behind the impenetrable barrier of the event horizon, and so there was no overt violation of causality. Acording to the mathematics wich Calvin had accessed, there could be none, since there trajectories could never pass back into the external universe. Yet they did. What the mathematics had overlooked was the special case of the tiny subset-of-a-subset-of-a-subset of trajectories which actually carried quanta back to the birth of the black hole, when it collapsed in the supernova detonation of its progenitor star.

At that instant, the minute outward pressure exerted by the particles arriving from the future served to delay the gravitational infall.

The delay was not even measurable, it was barely longer than the smallest theoretical subdivision of quantised time. But it existed. And, small though it was, it was sufficient to send ripples of causal shock propagating back into the future.

These ripples of causal shock met the incoming particles and established a grid of causal interference, a standing wave extending symmetrically into the past and the future.

Enmeshed in this grid, the collapsed object was no longer sure that it was meant to be a black hole. The initial conditions had always been borderline, and perhaps these entanglements could be avoided if it remained poised above its Schwarzschild radius; if it collapsed down to a stable configuration of strange quarks and degenerate neutrons instead.

It flickered indeterminately between the two states. The indeterminacy crystallised, and what remained behind was something unique in the universe -except that elsewhere, similar transformations were being wrought on other black holes, similar causal paradoxes coming into being.

The object settled on a stable configuration whereby its paradoxical nature was not immediately obvious to the outside universe. Externally, it resembled a neutron star -for the first few centimetres of its crus, at least. Below, the nuclear matter had been catalysed into intrincate forms capable of lightning-swift computation, a self-organisation which had emerged spontaneously from the resolution fo its two opposed states. The crust seethed and processed, containing information at the theoretical maximum density of storage of matter, anywhere in the universe.

And it thought

Below, the crust blended seamlessly with a flickering storm of unresolved possibility, as the interior of the collapsed object danced to the music of acausality. While the cust ran endless simulations, endless computations, the core bridged the future and the past, allowing information to channel effortlessly between them. The crust, in effect, had become one element of a massive parallel-processor, except that the other elements in its array were the future and past versions of itself.

And it knew.

It knew that, even with this totality of processing power strewn across the aeons, it was only part of something much larger.

And it had a name.

"Al impedir los fracasos de la Realidad, la Eternidad también impide el logro de los triunfos. Sólo haciendo frente a las grandes pruebas puede la Humanidad elevarse a nuevas y mayores alturas.

"It so happens that the work which is likely to be our most durable monument, and to convey some knowledge of us to the most remote posterity, is a work of bare utility; not a shrine, not a fortress, not a palace but a bridge. This is in itself characteristic of our time"

A menudo me he preguntado qué diria el habitante de la isla de Pascua que cortó la última palmera mientras lo estaba haciendo. Al igual que los leñadores modernos, ¿gritó; <<¡Empleo ya, no hay árboles!>>? ¿O pensó: <<La tecnología resolverá nuestros problemas, encontraremos un sustituto de la madera>>? ¿O acaso dijo: <<No tenemos pruebas de que no haya palmeras en algún otro lugar de Pascua, tenemos que investigar más; su propuesta de prohibir la tala es prematura y está impulsada por quienes siembran el miedo>>? Preguntas similares surgen en para todas las sociedades que han deteriorado inadvertidamente el medio ambiente.

Colapso, de Jareed Diamond.