Palimpsest Read Online Free PDF Page B

intelligence, will drift into strange new configurations. Two hundred and fifty million years after the sixth great extinction, the scattered continents will reconverge on a single equatorial supercontinent, Pangea Ultima, leaving only the conjoined landmass that was Antarctica and Australia adrift in the southern ocean. As the sun brightens, so shall the verdant plains of the Earth; oceanic algal blooms raise the atmospheric oxygen concentration close to 25 percent, and lightning-triggered wildfires rage across the continental interior. It will be an epoch characterized by rapid plant growth, but few animal life-forms can survive on land—in the heady air of aged Earth, even waterlogged flesh will burn. And the sun is still brightening …
    SLIDE 8.
    Seven hundred and fifty million years later. The brightening sun will glare down upon cloud-wreathed ancient continents, weathered and corroded to bedrock. Even the plant life has abandoned the land, for the equatorial daytime temperature is perilously close to the boiling point of water. What life there is retreats to the deep ocean waters, away from the searing ultraviolet light that splits apart the water molecules of the upper atmosphere. But there’s no escape: the oceans themselves are slowly acidifying and evaporating as the hydrogen liberated in the ionosphere is blasted into space by the solar wind. A runaway greenhouse effect is well under way, and in another billion years Earth will resemble parched, hell-hot Venus.
    SLIDE 9.
    Four-point-two billion years after the brief cosmic eyeblink of Earthly intelligence, the game is up. The dead Earth orbits alone, its moon a separate planet wandering in increasingly unstable ellipses around the sun. Glowing dull red beneath an atmosphere of carbon dioxide baked from its rocks, there will be no sign that this world ever harbored life. The sun it circles, a sullen-faced ruddy ogre, is nearing the end of its hydrogen reserves. Soon it will expand, engulfing the inner planets.
    But events on a larger scale are going to spare the Earth this fate. For billions of years, the galaxy in which this star orbits has been converging with another large starswarm, the M-31 Andromeda galaxy. Now the spiraling clouds of stars are interpenetrating and falling through each other, and the sun is in for a bumpy ride as galaxies collide.
    A binary system of red dwarfs is closing with the solar system at almost five hundred kilometers per second. They are going to pass within half a billion kilometers of the sun, a hairbreadth miss in cosmic terms: in the process they will wreak havoc on the tidy layout of the solar system. Jupiter, dragged a few million kilometers sunward, will enter an unstable elliptical orbit, and over the course of a few thousand years it will destabilize all the other planets. Luna departs first, catapulted out of the plane of the ecliptic; Earth, most massive of all, will spend almost five million years wobbling between the former orbits of Venus and Saturn before it finally caroms past Jupiter and drifts off into the eternal night, the tattered remnants of its atmosphere condensing and freezing in a shroud of dry ice.
    Slow Recovery
    Pierce was to remain on official convalescent leave for an entire year-subjective. His heart had been torn to shreds by a penetrator round; repairing the peripheral damage, growing a new organ in situ, and restoring him to physical condition was a nontrivial matter. Luckily for him, the fatal shooting had happened in the middle of a multiple-overwrite ambush that was finally shut down by Control Majeure using weapons of gross anachronism, and they’d whisked his bleeding wreckage out through a timegate before he’d finished drumming his heels.
    Nevertheless, organ regeneration—not to mention psychological recovery from a violent fatal injury—took time. So, rather than shipping him straight to the infirmary in the alpine monastery in Training Zone 25, he was sent to recover in the Rebirth