Authors: Robert L. Forward
Although many times hotter than the Sun, the neutron star was not a hot ball of gas. Instead, the 67-billion-gee gravity field of the star had compressed its blazing matter into a solid ball with a thick crust of close-packed, neutron-rich nuclei arranged in a
crystalline lattice over a dense core of liquid neutrons. As time passed, the star cooled and shrank. The dense crust fractured and mountains and faults were pushed up. Most crustal features were only a few millimeters high, but the larger mountain ranges rose up almost ten centimeters, poking their tops above the iron-vapor atmosphere. The mountains were the highest at the east and west magnetic poles, for most of the meteoric material that fell on the star was directed there by the magnetic field lines.
The temperature of the star had fallen since its birth. The neutron-rich nuclei on the glowing crystalline crust could now form increasingly more complex nuclear compounds. Since the compounds utilized the strong nuclear interaction forces instead of the weak electronic molecular forces that were used on Earth, they worked at nuclear speeds instead of molecular speeds. Millions of nuclear chemical combinations were tried each microsecond instead of a few per microsecond, as on Earth. Finally, in one fateful trillionth of a second, a nuclear compound was formed that had two very important properties: it was stable, and it could make a copy of itself.
Life had come to the crust of the neutron star.
Still unseen by human eyes, the white-hot neutron star continued to approach the Solar System. As the surface of the star began to cool through that small temperature range that was most conducive to nucleonic life, the original replicating nuclear molecule diversified and became more complex. Competition for the simpler nonliving molecules that served as food became more intense. Soon the primordial manna that had covered the crust was gone, and in its place were clumps of hungry cells. Some clumps of cells found that their topsides,
which faced outward toward the cold, dark sky, were constantly at a lower temperature than their undersides, which were in contact with the glowing crust. They raised a canopy of skin up away from the crust and soon were running an efficient food-synthesis cycle using the heat engine that they had arranged between a stiff taproot penetrating deep into the hot crust and the cool canopy above.
The canopy was a marvel of engineering. It used stiff crystals embedded with superstrong fibers to form a twelve-pointed cantilever beam structure that raised the thin upper skin against the 67-billion-gee gravity field of the star. Of course, a plant’s beam-structure couldn’t lift its topside very far. A plant might be as much as five millimeters across, but it could only raise a canopy up a millimeter.
The plants paid a price for their canopies and supporting frame. They were rigid and had to stay where they had rooted. For many, many turns of the star, nothing moved except for an occasional spray of pollen from the tip of a cantilever beam on one plant, followed by the contraction of a flap at the tip of a nearby plant. Then, many turns later, that action would be followed by the dropping of a ripe seed pod, which rolled away in the continual winds.
One turn, a rolling seed pod broke against a chunk of crust. Its seeds scattered and several of them started to grow. One was more vigorous than the others, and soon its canopy began to rise above those of its slower siblings. Suffocated in the heat radiated from the star below and the underside of the taller plant above, most of the smaller seedlings died.
One, however, underwent a strange transformation as its body functions started to fail. It had a mutant enzyme whose normal function was the fabrication and repair of the crystalline structure that held up the canopy. But under the influence of the distorted nucleonic
chemistry of an organism near death, the enzyme went wild and dissolved the crystalline structure it was designed to protect. The plant turned into a sac full of juice and fibers, and flowed down the slight slope upon which it had been rooted to a new resting place. The twelve pollen sprayers, slightly photosensitive in order to provide the optimum orientation for the canopy of the plant, worked their way around to the top. Now that the organism was out from under the blocking canopy of the larger plant, the errant enzyme controlled itself again. The plant sent down roots, rebuilt its canopy, and proceeded to give and receive many sprays of pollen. The mobile plant had many seedlings, all of which had the ability to dissolve their rigid structure and move if the conditions weren’t right for optimum growth.
Soon the first animals roamed the surface of the neutron star, stealing seed pods from their immobile cousins and learning that there were many good things to eat on the star—especially each other.
Like the plants they came from, the neutron star animals were only five millimeters across, but, lacking stiff internal structures, they were flattened by the gravitation. The twelve photosensitive pollen sprayers and flaps became eyes, but they still retained their original reproduction function. The animals could grow “bones” whenever they wished. Most of the time these were degenerate forms of the cantilever beams that were used to hold their eyes up on stalks so they could see further; but, with a little concentration, a bone could be formed anywhere inside the skin sac. However, speed of bone forming was paid for in quality: the bones were made solely of crystallized internal juices; they did not contain the embedded fibers that made the plant structure so strong. That procedure took too much time.
Unlike the plants, the animals had to contend with
the star’s magnetic field. The plants didn’t move, so they didn’t mind that they were stretched into a long ellipse aligned along the magnetic field lines. The bodies of the animals were also stretched into long ellipses, but since their eyes were stretched by the same amount, they were not aware of the distortion. However, the animals found that it was much harder to move across the magnetic field lines than along them. Most gave up trying. To them the world was nearly one-dimensional. The only easy directions in which to travel were “east” and “west”—toward the magnetic poles.
After a long time, plants and animals existed all over the surface of the neutron star. Some of the smarter animals would look up at the dark sky and wonder at the points of light they saw moving slowly across the blackness as the neutron star turned. The animals in the southern hemisphere of the star were especially bewildered by the very bright spot of light that stayed fixed over the south pole. It was Earth’s Sun. The light was so bright and close that it didn’t twinkle like the other specks of light. But except for using the star as a convenient navigation beacon to supplement their magnetic directional sense, none of the animals bothered to think more about the strange light. There was always plenty of food from the constantly growing plants and the smaller animals. An animal doesn’t need to develop curiosity and intelligence if it has no problems that need solving.
The blinking, radiating, spinning neutron star was now one-tenth of a light year from the Sun. After a half-million years the star had cooled, and its spin speed had slowed to only five revolutions per second. It still sent out pulses of radio waves, but these were but a weak remembrance of its brilliant earlier days.
In a few hundred more years the neutron star would pass by the solar system at a distance of 250 astronomical units. Its gravity would perturb the outer planets, especially Pluto, way out at 40 AU from the sun. But Earth, snuggled up to Sol in its orbit of one AU radius, would scarcely notice the passage. The star would then leave the Solar System—never to return.
By now the life forms on Earth had invented the telescope, but even this was inadequate to see the tiny pinpoint of light in the vast heavens unless one knew exactly where to look.
Would it pass unseen?
Jacqueline Carnot strode over to a long table in the data processing lab in the CCCP-NASA-ESA Deep Space Research Center at CalTech. A frown clouded her pretty face. The cut of her shoulder-length brown hair and her careful choice of tailored clothing stamped her at once as “European.”
Her skirt, blouse and clogs were her only items of clothing. It was not that she did not own stockings—and purses—and makeup—and rings—and perfume—and other “women’s things;” it was just that she was in too much of a hurry in the morning to bother with them, for she had work to do. The French government had not given her a state fellowship to study at the International Space Institute so she could spend all morning getting dressed.
The slender woman swiftly cleared the table of its accumulated scraps of paper and tossed down a long data record at one end. The cylinder of paper rolled obediently across the table, then obstinately off the end and five meters across the floor before it finally stopped. Jacqueline left the roll on the floor and started to analyze the data. This menial task would normally have been handled by a computer. Unfortunately, computers now
insisted on a charge number for everything, and when Jacqueline had logged on this morning she had found that the meager balance that she had been saving out of Professor Sawlinski’s allocation for her thesis had been swallowed up by another retroactive intercurrency account readjustment. She knew that Sawlinski had plenty of rubles in his research budget; but, without his budget authorization and his personal approval to the computer (by the crypto-password that she knew, but dared not use), she was reduced to waiting and hand-processing until he returned.
Actually, it was fun working with the numbers in this personal way. With the computer doing the analysis, the numbers would be crammed into digital bins whether they were real data or noise, and right now there was a lot of scruffy noise on the graph.
The data Jacqueline was analyzing came from the low frequency radio detectors on the old CCCP-ESA Out-of-the-Ecliptic probe that was the first major cooperative effort between the Soviets and Europeans. Back in the early days of the race to the Moon, the Europeans had supplied the first Soviet lunar rover with laser retroreflectors. Then, after a disastrous experience with the Americans in which one of America’s four precious Shuttle spacecraft and Europe’s only SpaceLab had exploded on the launch pad, the Europeans had turned back to the East for cooperation. The Europeans built the instrumentation for an Out-of-the-Ecliptic spacecraft that was launched by one of the giant Russian launch vehicles. The craft first traveled five astronomical units out to Jupiter. But once there, instead of taking pictures and going on to other planets as previous spacecraft had done, it went under Jupiter’s south pole- to shoot straight up out of the plane formed by the orbits of the planets.
As the spacecraft climbed up out of the ecliptic plane, its sensors began to see a new picture of the Sun.
The magnetic fields that blossomed out from the sunspots at the middle latitudes of the Sun were now attenuated, while new effects began to dominate the scene.
The data from the CCCP-ESA Out-of-the-Ecliptic probe had been thoroughly analyzed by many well-funded scientific groups early in the mission. The information gathered had shown that the Sun had a case of indigestion. It had eaten too many black holes.
The scientists found an extremely periodic fluctuation in the strength of the Sun’s polar magnetic field. The magnetosphere of the Sun had many variations, of course. Each sunspot was a major source of variability. However, sunspots were irregular in time and were so strong in the middle latitudes that they dominated everything. It was not until the OE probe was above the Sun, sampling data for long periods of time, that the finely detailed, highly periodic variations in the radio flux were found and interpreted as periodic variations in the Sun’s magnetosphere. It was finally concluded that the Sun had four dense masses, probably miniature primordial black holes, orbiting around each other deep inside the sun. These disturbed the Sun’s normal fusion equilibrium by gnawing away at its bowels. The effect of the black holes on the Sun would become serious in a few million years, but all they did now was bring on an occasional ice age.
Although the human race realized that the Sun was not a reliable source of energy for the long term, there was little they could do about it. After a short flurry of national and international concern over the “death of the Sun,” the human race settled down to solving the insoluble problem in the best way that they knew—they ignored it and hoped it would go away.
It was now two decades later. Miraculously, one of the two communication transmitters on the satellite and three of the experiments were still running. One
of them was the low frequency radio experiment. Its output was sprawled across a table and clown a computation-lab floor, slowly being marked up by the swift, slender fingers of a determined graduate student.
“Damn! Here comes the scruff again,” Jacqueline muttered to herself as she slid the long sheet across the table and noticed that the slowly varying trace with the complex sinusoidal pattern began to blur. Her job for her thesis was to find another periodic variation in that complex pattern that would indicate that there were five (or more) black holes. Failing that, she needed to prove that there were only four. (At least she had been able to get her peripatetic advisor to agree that a well-documented negative result would be an adequate thesis.)