A Step Farther Out

by Jerry Pournelle

  The Empire is what it is largely because of the Alderson Drive and Langston Field. Without the Drive an Empire could not form. Certainly an interstellar Empire would look very different if it had to depend on lightspeed messages to send directives and receive reports. Punitive expeditions would be nearly impossible, hideously expensive, and probably futile: you'd be punishing the grandchildren of a generation that seceded from the Empire, or even a planet that put down the traitors after the message went out.

  Even a rescue expedition might never reach a colony in trouble. A coalition of bureaucrats could always collect the funds for such an expedition, sign papers certifying that the ships are on the way, and pocket the money. . . in sixty years someone might realize what had happened, or not.

  The Langston Field is crucial to the Empire, too. Naval vessels can survive partial destruction and keep fighting. Ships carry black boxes—plug-in sets of spare parts—and large crews who have little to do unless half of them get killed. That's much like the navies of fifty years ago.

  A merchant ship might have a crew of forty. A warship of similar size carries a crew ten times as large. Most have little to do for most of the life of the ship. It's only in battles that the large number of self-programming computers become important. Then the outcome of the battle may depend on having the largest and best-trained crew—and there aren't many prizes for second place in battle.

  Big crews with little to do demand an organization geared to that kind of activity. Navies have been doing that for a long time, and have evolved a structure that they tenaciously hold on to.

  Without the Field as defense against lasers and nuclear weapons, battles would become no more than offensive contests. They'd last microseconds, not hours. Ships would be destroyed or not, but hardly ever wounded. Crews would tend to be small, ships would be different, including something like the present-day aircraft carriers. Thus technology dictates Naval organization.

  It dictates politics, too. If you can't get the populace, or a large part of it, under a city-sized Field, then any given planet lies naked to space.

  If the Drive allowed ships to sneak up on planets, materializing without warning out of hyperspace, there could be no Empire even with the Field. There'd be no Empire because belonging to an Empire wouldn't protect you. Instead there might be populations of planet-bound serfs ruled at random by successive hordes of space pirates. Upward mobility in society would consist of getting your own ship and turning pirate.

  Given Drive and Field, though, Empires are possible. What's more likely? A representative confederacy? It would hardly inspire the loyalty of the military forces, whatever else it might do. (In the War Between the States, the Confederacy's main problem was that the troops were loyal to their own State, not the central government.)

  Each stellar system independent? That's reasonable, but is it stable? Surely there might be pressures toward unification of at least parts of interstellar space.

  How has unification been achieved in the past? Nearly always by conquest or colonization or both. How have they been held together? Nearly always by loyalty to a leader, an Emperor, or a dynasty, generally buttressed by the trappings of religion and piety. Even Freethinkers of the last century weren't ashamed to profess loyalty to the Widow of Windsor. . .

  Government over large areas needs emotional ties. It also needs stability. Government by 50%-plus-one hasn't enjoyed particularly stable politics—and it lasts only so long as the 50%-minus-one minority is willing to submit. Is heredity a rational way to choose leaders? It has this in its favor: the leader is known from an early age to be destined to rule, and can be educated to the job. Is that preferable to education based on how to get the job? Are elected officials better at governing, or at winning elections?

  Well, at least the counter-case can be made. That's all we intended to do. We chose a stage of Empire in which the aristocracy was young and growing and dynamic, rather than static and decadent; when the aristocrats are more concerned with duty than with privilege; and we made no hint that we thought that stage would last forever.

  RANDOM DETAILS

  Robert Heinlein once wrote that the best way to give the flavor of the future is to drop in, without warning, some strange detail. He gives as an example, "The door dilated."

  We have a number of such details in MOTE. We won't spoil the book by dragging them all out in a row. One of the most obvious we use is the personal computer, which not only does computations, but also puts the owner in contact with any near-by data bank; in effect it will give the answer to any question whose answer is known and that you think to ask.

  Thus no idiot block gimmicks in MOTE. Our characters may fail to guess something, or not put information together in the right way, but they won't forget anything important. The closest that comes to happening is when Sally Fowler can't quite remember where she filed the tape of a conversation, and she doesn't take long to find it then.

  On the other hand, people can be swamped with too much information, and that does happen.

  There were many other details, all needed to keep the story moving. A rational kind of space suit, certainly different from the clumsy things used now-. Personal weapons. The crystal used in a banquet aboard MacArthur: crystal strong as steel, cut from the windshield of a wrecked First Empire reentry vehicle, indicating the higher technology lost in that particular war. Clothing and fashion; the status of women; myriads of details of everyday life.

  Not that all of these differ from the present. Some of the things we kept the same probably will change in a thousand years. Others. . . well, the customs associated with wines and hard liquors are old and stable. If we'd changed everything, and made an attempt to portray every detail of our thousand-year-advanced future, the story would have gotten bogged down in details.

  MOTE is probably the only novel ever to have a planet's orbit changed to save a line.

  New Chicago, as it appeared in the opening scenes of the first draft of MOTE, was a cold place, orbiting far from its star. It was never a very important point, and Larry Niven didn't even notice it.

  Thus when he introduced Lady Sandra Liddell Leonovna Bright Fowler, he used as viewpoint character a Marine guard sweating in hot sunlight. The Marine thinks, "She doesn't sweat. She was carved from ice by the finest sculptor that ever lived."

  Now that's a good line. Unfortunately it implies a hot planet. If the line must be kept, the planet must be moved.

  So Jerry Pournelle moved it. New Chicago became a world much closer to a somewhat cooler sun. Its year changed, its climate changed, its whole history had to be changed. . .

  Worth it, though. Sometimes it's easier to build new worlds than think up good lines. . .

  PART THREE: A STEP FARTHER IN: BLACK HOLES

  Commentary

  I was one of the first science fiction writers to use black holes in a story. Not the first, I hasten to add; but I did make the first use of gravitation waves, and therein lies a tale.

  I had just published my story "He Fell Into a Dark Hole" and was in fact reading it—writers generally do read their own work the first time they see it in print—when the telephone rang. The caller was Dr. Robert Forward of the Hughes Research Laboratories; Forward, I later learned, is one of the foremost authorities on gravitation, and holds patents on gadgetry such as a "mass detector."

  He had been preparing a paper on gravitation waves and how they might prove to be dangerous; that was the theme of my story; and I had beaten him into print. So not only did I make first use of them in science fiction, but my story may have the first publication anywhere to draw attention to certain aspects of gravity waves.

  The result is that I am, to many fans, a sort of "proprietor" of black holes; a role I'm willing to fill for a while. Which gives me the right to tell you about them, as this section does.

  Gravity Waves, Black Holes, and Cosmic Censors

  I suppose most readers are at least partly aware of the ongoing research on detection of gravitational waves,
but it does no harm to summarize a bit. In the Newtonian universe, gravity is a "force" that acts through a field; that is, although it is 10 times weaker than electromagnetism, it's not fundamentally different.

  This holds true in the realm of special relativity also: special relativity is the theory that asserts that no material object, and no signal, can travel faster than light. There's a lot of evidence for special relativity, and no really good counter theory lurks in the wings to take its place.

  The general theory of relativity is another breed of cat entirely. There are several contenders in that realm, and experimental evidence offers no clear cut way to choose one or another. General relativity does away with gravity fields altogether: in that theory, gravity results from the geometry of space, and is not a "force" at all.

  (That is: mass—or energy for that matter—distorts space, bending it; and it is this curvature of the fabric of space itself that causes the effects we call "gravity.")

  Whether gravity fields "exist" or merely result from geometry, nearly all theorists believe gravitational attraction propagates with the speed of light. If matter is created—or destroyed—the rest of the universe won't be instantly affected, but must wait until the gravitational effect, traveling at light speed, reaches it.

  Thus "gravitation waves," which will have a frequency and an amplitude much like light, but which may also have some rather strange properties as well.

  In theory, if we could detect and examine gravitational waves, we might be able to tell whether they result from a field and are thus similar to magnetism, or if they are merely a property of space and its geometry. Unfortunately, gravity is an incredibly weak force. It requires the mass of the whole earth merely to pull things with a puny 980 cm/sec2 acceleration—and we can overcome that with rather small magnets, or chemical rockets, or even our own muscles when we jump.

  Because gravity is so weak, it's hard to play with. You can't turn on a "gravity wave generator" and fiddle with the resulting forces to see if they refract, or can be tuned, or whatever. You can't wiggle a mass to generate gravity waves, because you can't get a large enough mass held into place to be wiggled. It's not even possible to blow off an atomic weapon, turning some matter into energy, and measure the effect of the matter vanishing; the effect is just too small to be noticed, and it's hidden among the rather drastic side effects.

  However, there are a number of theoretical ways that gravity waves might be generated by the universe: stars collapsing into black holes or neutronium would do it, for example. The universe might be riddled with gravitational waves, but they'd be terribly weak, and require delicate and sophisticated apparatus to detect them.

  Some years ago, Dr. Joseph Weber of the University of Maryland decided to build a gravity wave antenna. He took a large aluminum cylinder and covered it with strain gauges. The idea was that so long as the cylinder was acted on only by the steady gravity of Earth, it would be in a stable configuration, but if a gravity wave passed through it, the cylinder would be distorted, and the strain gauges would show it.

  He had to compensate for temperature, and isolate it from vibration, and worry about a lot of other things, but the technology had been developed: the antenna was built. It was incredibly sensitive, able to detect distortions on the order of an atomic diameter. It was also able to detect student demonstrations outside the library, trucks rumbling along the highway a mile distant, and other unwanted events.

  The solution to the latter problem was simple: build another copy of the antenna and place it 1000 kilometers away; now hook the two together, and pay no attention to any event that doesn't affect both. Such "coincidences" should be due to a force affecting both antennae—earthquakes take time to propagate and their effects move much slower than lightspeed—the output should be reliable.

  Unfortunately, it isn't as straightforward as that. The instruments must be very sensitive, and thus there's a lot of chatter from them. By the laws of chance, some of this chatter will be simultaneous, or near enough so, and thus you are guaranteed some false positive results. The output of the gravity wave detectors, therefore, needs careful analysis to decide what's real data and what's chance.

  Weber immediately got results. He got a lot of results, far too many for chance. Unfortunately, there were far too many for cosmologists to believe. As a result of Weber's early reports, some cosmologists estimated that as much as 98% of the universe must be inside black holes.

  The argument went this way: something is producing gravity waves. We can't see enough matter to account for the events, but normal matter falling into a black hole would produce gravity waves. Therefore—

  There were other cosmologists who wanted to believe this for different reasons. Readers familiar with black holes must excuse me: it's now necessary to discuss their basics for a moment.

  * * *

  A black hole is a theoretical construct that can be derived from both general relativity and the older Newtonian universe; in fact, the first speculations about black holes come from Laplace back in 1798. If you take enough matter and squeeze it small enough, you will eventually get so much gravitational force that nothing can prevent the matter from continuing to collapse.

  In Einsteinian terms, the space around the matter becomes curved into a closed figure, but the result is the same: the matter is squeezed to infinite density. Long before it reaches that state, though, there is a region around the matter at which the escape velocity is greater than the speed of light.

  The effect of that should be pretty obvious. If light can't escape, you can't see down into the hole. Moreover, anything that goes down in the hole can never come out: that is, if you accept the speed of light as the top limiting velocity of the universe, nothing can come out.

  The area at which space is curved into a closed figure—or the region at which the escape velocity is equal to the speed of light—is known as an event horizon, and interestingly enough both Newtonian and Einsteinian equations give the same location to it.

  It is the region at which

  R = 2GM/c2 (Equation One)

  where R is the radius from the center, G is the universal constant of gravitation, and c is the speed of light For our sun, that radius is on the order of 2 kilometers: if the sun is ever squeezed that small, we'll never be able to see it again.

  An observer diving into the black hole would never know when he had crossed the event horizon. He could continue to send signals to his friends outside, and as far as he could tell, they would go right on up and out.

  Those outside the hole, though, can never under any circumstances receive information from inside it.

  Now, as it happens, if we measure the total amount of matter in the universe, and plug that in for M in equation one; and we take the furthest object we can observe and plug that in for R; then the equation almost balances.

  Almost, but not quite. There isn't enough matter in the universe; we're missing from 20 to 90%, depending on whose figures you use for M and R.

  If the equation were to balance, space would be curved into a closed figure at the boundaries of the universe, and we'd live in a closed universe.

  Eventually, in a closed universe, those galaxies receding from us will stop and come back, and the whole universe will be packed into a big wad at the center. What happens after that is debatable, but a number of cosmologists want badly to believe in a closed universe.

  It also means, of course, that we live inside a black hole ourselves: that is, our whole universe is a black hole.

  If we don't live in a closed universe, the receding galaxies will go right on receding, and this disturbs some theorists. Thus, Weber's coincidences were welcome in many cosmological circles. Others tried to build gravitational antennae to confirm his results.

  * * *

  Then a second startling result came out of Weber's shop. It appeared that there was a 12 hour sidereal cycle to the coincidences, and furthermore, that this cycle was related to the galactic plane. In other words, gravitation
al waves originated in the galactic center.

  We have a good estimate of the distance to the galactic center, and thus were able to estimate how large an effect at the center of the galaxy would be required to deliver that much force to us out here on our spiral arm. The result was once again dismaying. Far too much energy was apparently being turned into gravitational waves.

  Now the energy radiating from the galactic center could be either sprayed out in all directions, obeying the inverse square laws, or it could be "beamed" into the galactic plane. Obviously less total energy is involved if it is "beamed," but what mechanism might account for that?

  The speculations were many, imaginative, and varied; they were also rather frightening.

  * * *

  Let's take a moment to go back to black holes. When matter gets dense enough to satisfy equation one, and the event horizon forms, things don't just stop there. The matter goes on collapsing; we just can't see it any longer.