Dark Lightning (Thunder and Lightning) (9 page)

200,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000

That’s the mass of all the stars there are, and it seems like so much. It sounds pretty crowded, too, but it’s not. You could travel almost eternally through it at the speed of light and your chances of hitting a star would be virtually zero. Galaxies collide with each other all the time, vast conglomerations of a hundred billion stars, but the stars are so small, relatively, and so spread out with such immense distances between them that collisions of stars are very rare.

And stars are not even the bulk of it. If you add in the free hydrogen and helium
between
the stars and galaxies, you would have to multiply that huge number by four.

And
that’s
far from the end of it. That is the
visible
universe. We see stars by the light they give off, and clouds of gas by the effects they have on the starlight passing through them. Matter, all of it matter. Matter generates gravity.

However, that visible matter is only a small portion of what’s
really
there. From the way galaxies behave and from the way light is distorted when there’s nothing obvious there to distort it, and from other clues, cosmologists have deduced that there’s a lot more matter out there than the stuff we can see. In fact, there’s
five times
as much.

But we’re
still
not done.

I’m not going to deal with the current prevailing theory of how it all began, the Big Bang theory. I always saw it as an explosion, with everything rushing away from a center point, like you see in films of an explosion. Papa says this is only partly true, but it can be a useful way to visualize it. But the logic breaks down quickly. From where we are, in the Milky Way galaxy, everything but our very close neighboring galaxies seems to be rushing away from us. The more distant it is, the faster it is rushing away. What, was it something we said? Do we smell bad?

Since no matter which direction you look, everything is moving
away
from us, you’d think that meant we just happen to be the center of the universe. That would be a nice thing to think, wouldn’t it? Like before telescopes and such things, people thought the Earth was the center of the universe, and Old Sun and all the stars and planets revolved around it. Made them sort of special, and don’t we all want that?

But it ain’t so. Papa says that no matter where we were in the universe, everything would seem to be rushing away from us. That’s because since the universe is expanding, space
itself
is expanding. Papa used a balloon to show us how that made sense. You draw dots on the surface of a balloon, and say those are galaxies. Now blow the balloon up. All of the dots move away from all the other dots, because the balloon is stretching. That’s a two-dimensional model of what’s happening in three dimensions. The balloon’s surface is two-dimensional, but it’s curved.

So, the universe is expanding. But gravity—including all that dark matter—should be tending to slow it down. Eventually, it would stop expanding and start to collapse back on itself, like the rocks thrown in the air by an explosion on a planet eventually stop rising and fall back to the ground.

Except about a hundred years ago they found out that’s not what’s happening. Everybody expected that the rate of expansion would be slowing down, so that it would eventually stop and start contracting. Another possibility was that the rate of expansion would stay steady. The third, and what most scientists thought was the least likely to be true, was that the rate of expansion could be
increasing
.

And that’s exactly what they found. In some unimaginable future, the universe will stretch so thin that the light from one galaxy would be unable to reach any other galaxy. Eventually, all the stars would burn out, and the universe would consist of the dead cinders of stars, black holes, and uncountable googolplexes of cubic light-years of cold, empty space.

So have fun while you can, because the future is bleak. If you live forever, that is.

—

But this discovery raised more questions than it answered.

To have all those galaxies rushing away from each other faster and faster, there needs to be something pushing them away from each other, and pushing pretty hard. Remember, their own gravity is pulling them
toward
each other, and it’s helped along by the gravitational attraction of all that dark matter—four times the amount of visible matter, and thus four times as strong.

This other stuff, this dark energy, or
dark lightning
, as Papa prefers to call it, has to overcome all that, and then some.

How
it does it wasn’t solvable at the time since we didn’t have the foggiest notion of what it was or where it was hiding. We could only infer it
was
there because something had to be there to keep pushing everything apart faster and faster. But it was possible to estimate how
much
of it there was if we could estimate just how fast the rate of expansion was increasing. Then we could calculate just how much energy it would take to move all those quindecillions of tons of dark and light matter at that rate.

Turns out it’s a lot.

Since matter and energy are convertible, one into another, by the old Einstein equation of E=mc
2
, they were then able to get a better picture of the stuff the universe is really made of. Turns out all that dark lightning is the most common stuff in the universe, way more of it than dark or visible matter combined. Almost three times as much.

So here’s how it adds up:

Dark lightning: 70 percent of the universe.

Dark matter: 25 percent of the universe.

The stuff we can see: 5 percent of the universe.

Of that 5 percent, 4 percent is free hydrogen and helium, leaving 1 percent for everything else.

Of the “everything else,” that 1 percent, about 60 percent is stars, which are mostly hot hydrogen and helium, 35 percent is those gosh-darn neutrinos, and 5 percent is left over for the “heavy” elements: the cores of stars ready to go supernova, the cores of gas-giant planets like Jupiter and Saturn, rocky planets like Earth and Mars, asteroids,
Rolling Thunder
, you and your family, me and my sister and our family, and my little blue budgie, Chip.

In the hundred years since its discovery, Papa said some progress has been made on finding out what and where the dark lightning is. But almost all of it is on paper, or rather in huge computer models.

Cosmologists and astronomers and physicists and mathematicians and people who are combinations of those disciplines—because there’s a lot of overlap—love to sit around and think about it all. The astronomers bring in new data as their telescopes get better and better. The physicists smash atoms together in larger and larger and more powerful machines. The biggest one, when the ship left, was around the equator of Ceres. They get more data about how the basic stuff of the universe is put together by breaking it apart and seeing what comes out. Then the cosmologists and mathematicians get to work on all that data and try to come up with a theory that accounts for it all, including dark matter and dark lightning.

That’s what we have when it comes to dark lightning. Theories. About twenty of them, according to Papa.

Theories come in varying degrees of reliability.

The “theory” of gravitation is proven to everyone’s satisfaction, in that we all agree that gravity is an inherent property of all matter. Our understanding of just
how
it does what it does is still far from complete—there are four or five theories about
that
—but the fact that gravity is a property of matter
in all cases
is a done deal.

The theory of relativity is proven out to twenty decimal places.

The theory of evolution is proven, both historically and experimentally, to a similar degree.

The Big Bang theory is just that: a theory that fits the known facts better than any other theory. Not proven, but robust, as the scientists say. It’s certainly incomplete and may never be completed, but it’s useful, and large parts of it
have
been proven.

All
the theoretical models of dark matter and dark lightning simply cannot stand in such company. If gravitational theory is a ten on a scale of one to ten, the best model for dark lightning would only rate a point zero one. There simply isn’t enough data to back any of them up, to “prove” them. Dark lightning remains almost as elusive as it was in the twentieth century.

Except that now Papa thinks he has figured out some things about it. And it’s not good news.

Cassie:

So that’s the background of what Papa was trying to tell us. A universe that is mostly made up of stuff we simply can’t see and can only detect through indirect means.

But all that was learned in observatories traveling at very sedate speeds, in orbit around Old Sun. For telescopes on Earth or the moon, that speed is 18 miles per second. For Mars, it’s about 15 miles/sec. For a telescope near Neptune, the orbital speed is only 3.3 miles/sec. The very most distant telescopes, way out in the Kuiper Belt, are hardly moving at all, relative to Old Sun.

There’s also the motion of the galaxy itself, which is spinning at the dizzying rate of one revolution every two hundred million years. The whole solar system is moving at about 170 miles per second. The whole Milky Way galaxy is moving relative to the center of mass of our local group of galaxies—the only ones that aren’t moving away from us like we’re a plague carrier—at 25 miles/sec.

It would be possible to add up all those velocities and come up with a number for Old Sun’s speed through the universe, but there’s really no point. Whatever it is, it is trivial compared to
Rolling Thunder
’s speed relative to Old Sun and to our destination.

Old Sun stirs up what is called a “bow shock” wave. It is where the solar wind becomes too weak to overcome the star’s passage through the interstellar medium. That’s an important concept.

The solar system’s movement as the galaxy rotates means little, as everything around it is moving at pretty much the same speed, including the interstellar medium, so its relative velocity is low.

Think of a boat plowing upstream on a raging river whose water is moving at forty miles per hour. The boat is also moving at forty miles per hour. Another boat with its engines off is being moved along by that same river. The first boat is going forty miles per hour
relative to the water
. Relative to the shore, it is motionless. The second boat is moving at forty miles per hour
relative to the shore
. The second ship is motionless, relative to the water.

The first ship encounters a great deal of resistance, the second ship encounters none. That second ship is Old Sun, moving with the rotation of the galaxy. Got it?

Rolling Thunder
is like that first ship, plowing through the water at great speed, but here the analogy fails. We are rushing through the interstellar medium of thin atoms of hydrogen and miniscule bits of dust, but the ship is so massive that it’s barely possible to register the tiny bit of resistance we’re encountering. It’s all soaked up and deflected by the million-mile bubble way out in front of us, so we’re traveling through the most perfect vacuum ever encountered by humans. But we
are
plowing through it, at a speed of 143,000 miles per second. That’s faster than any humans have ever traveled . . . and lived to tell about it.

Though that very much remains to be seen.

We haven’t lived to tell about it yet.

There’s the matter of those hundreds and hundreds of other ships that set out for the stars around midcentury. Only one of them ever returned, to devastating effect on all the countries of the North Atlantic. Whoever was aboard never had a word to say about their experiences at near-light speed; they were moving at near-light speed when they returned, almost fast enough to catch up with any radio signal they were sending out. It was a matter of “Here we com—
BANG!
”

What they actually managed to say was “Death to—
BANG!
” It was their second miscalculation, after their slightly faulty aim, so that their suicide ship only hit the Earth a glancing blow instead of impacting North America. Granddaddy Ramon says that anyone alive at that time could easily fill in the blank, as it was a phrase very popular for the first forty years of the twenty-first century:
Death to America
.

He also said most people had a pretty good idea of who the mass murderers were, too. At the time all the ships were leaving, much of the trouble on Earth was being stirred up by radical Muslims who wanted to return all the societies of the world to a point around the seventh century. It was a culture rich in people willing to commit suicide if it would hurt the “infidels.” They would strap explosives to their bodies or drive dynamite-laden vehicles into crowds of people and blow themselves up. Hard to believe, but true. Even children did this. History can be appalling, can’t it?

The impact with the Earth had all the hallmarks of radical Muslim terrorism. Right at the turn of the century, a group of them flew airliners full of people into skyscrapers full of people.

They got over it. The second part of the century was pretty much free of that kind of barbarism. The Muslims aboard
Rolling Thunder
are good, peaceful people. Not that there’s a lot of them, not fervent believers, anyway, though there are plenty of people with Islamic backgrounds. It ain’t discrimination, Travis says, at least not against Muslims. Strong, intolerant religious feelings of
any
kind were a deal breaker if you wanted to board
Rolling Thunder
. We have our religious people aboard—about 35 percent believe in a Supreme Being of some sort, according to the polls—and we have our churches and synagogues and mosques, and I’ve visited one of each on field trips, but if you believe in crap like discrimination against females or the infallibility of the Pope or don’t believe in evolution or gay rights, Travis didn’t want you aboard. So conservative Catholics, ultraorthodox Jews, and hard-shell evangelical Christians were just as unwelcome as wild-eyed Muslims.

Sorry, got off the subject there for a minute. Organized religion puzzles me. I’ve found the services interesting, for the ritual, but pretty boring overall. My version of spirituality is my own, thank you very much, not to be trotted out in public.

So we were discussing the one ship that returned from an interstellar voyage, out of hundreds that set out, and the near certainty that it was piloted by religious fanatics unafraid to die, or to kill millions of infidels—and even other Muslims, as they had done many times in the past—because as martyrs they were guaranteed a place in the afterlife with ninety-seven virgin sluts, or some horseshit like that.

Why did they survive when, so far as we can tell, no one else did?

That’s where the discussion began, in the Common Council Chamber.

—

Government is small in
Rolling Thunder
, in accordance with Travis’s libertarian leanings. Anything that can be done efficiently and competitively by private enterprise is left to take care of itself according to good old capitalist/socialist principles. But Travis is not a fanatic about it. He believes in democracy . . . up to a point. He
is
Captain Broussard, after all, and his word is the final one.

Each of the fifteen townships has an elected mayor and council, and each of them elects a representative to the Common Council, which elects a governor.

The CC meets in the Council Building, one of the nicest and largest structures in the ship, with what is probably the grandest interior. Travis didn’t want to spend a lot of time or money on new architecture, so he got the builders to dig out old plans of other buildings that he knew were serviceable and use those. The Council Building is an exact copy of the General Assembly Building of the United Nations, in New York.

That’s gone now, of course, torn down many years ago. When it existed, it sort of crouched at the feet of a much taller building, the Secretariat. The Council Building is made of white stone, long and narrow, and the roof swoops gradually, higher at one end than the other. One end has a lot of glass in it, and inside is a spacious, very-high-ceilinged lobby with four boomerang-shaped balconies overlooking it.

Behind that is the meeting chamber. It’s round and tapers upward to a domed ceiling. There’s a raised area backed by a gold wall that leans outward, bearing the seal of the good ship
Rolling Thunder
. That is flanked by two curved wooden walls that also lean. The rest of the room is filled with comfortable seating for a bit over a thousand people.

Polly and I were the only ones sitting in the audience. The lighting out there was from dim, overhead bulbs that created a restful ambience. We were trying to be as quiet and unobtrusive as church mice. We were there on sufferance.

Mama had been against it. But Travis had pointed out that if she barred us from the meeting, we might do damage to the building, drilling holes in it in our attempts to spy on them. Mama sighed one of her long-suffering sighs and relented.

The council platform was brighter. There was a long table up there, seven chairs on each side of a larger chair for the governor. There was a row of seats behind them, for aides and such. All those chairs were vacant, as were almost all the council chairs. Of the Common Council, only Governor Wang and two others were present. (In
Rolling Thunder
, not even the post of governor is full-time. Alice Wang taught Earth History at our school, and Polly and I had both been in her class. She had been a good teacher.)

The governor wasn’t sitting in her chair but standing to one side of the platform. Two people were in other seats at the table, and some others were either standing, pacing back and forth, or sitting with one haunch on the tabletop. Papa was one of those sitting in a chair, looking miserable. Travis was one of those pacing, and the only one talking at the moment, trying to explain what Papa had just told us all. Mama was standing behind Papa, massaging his shoulders.

Travis had gotten all the preliminaries out of the way quickly. With this group, he didn’t need to explain dark matter or dark lightning, except maybe to Governor Wang. The other people present were all friends of Papa and constituted Travis’s informal science advisory group.

“I didn’t know a lot of what I’m going to tell you,” Travis was saying. “Some of you may, but I’d better outline it briefly.

“At the time the rogue ship hit the Earth, a little over fifty years ago, we were not able to determine all that much about it. We knew its exact course coming in; all we had to do was draw a line from the hot plasma trail it left behind after being vaporized by the collision. But quite a few ships had gone out in that direction.

“People kept working on it, in astronomical records and back on the Earth, using improved equipment, both observational and computational. Little by little they teased out some more information. This is what Jubal learned a few years ago, before communications with Earth and Mars were shut down. Back on Mars, they are now 99 percent sure that the rogue ship was the
Mejd Allah
, which I’m told translates as the
Glory of Allah
. It was built by some Saudi billionaires with radical connections.”

Uncle Travis is a good storyteller. He had everyone’s undivided attention as he paced back and forth across the dais, never looking at anybody. Polly and I were transfixed. She had grabbed my hand and was squeezing it a bit, and I don’t think she even knew she was doing it.

“Remember, there was a positively mad scramble to build ships and head out for the stars not long after Manny and Kelly and Dak and Alicia and I got back from Mars in the
Red Thunder
. Then it tapered off, and the next big thing was going to be the
return
of the first ship from the stars.

“Never happened. No one came back.

“After a while, fewer and fewer ships were leaving. It was enough to give you pause, all those ships leaving, some of them now long overdue. What was happening to them? Until somebody figured that out, only crazy people were likely to board a starship.”

One of the council of mayors spoke up.

“This is all fascinating,” he said, “but I’m sure most of us have a pretty good understanding of the era of the diaspora. Where are you going with this, Captain?”

It was George Bull, the mayor of Freedonia Township. He was one of only three mayors present, plus Governor Wang. Naturally, it would be a politician to interrupt the flow of the story. He was built like his name, with a barrel body and cannonball-bald head, but the face pasted on the front of the head was more of a bullfrog’s, with big wet lips and goggling eyes.

“Just ordering my thoughts, Mayor Bull,” Travis said. “If you’ll bear with me a few more minutes, we’ll get to the reason I invited you all here.”

It had been more of an order, I knew, but Travis was being polite.

“I’d like to hear it all, Mayor Bull,” said one of the other mayors, Oringo Ngoro, the mayor of Sweet Apple township. “I’m not up on my solar history, I admit it.”

We had visited Mayor Ngoro’s orchards and picked apples, of which he had about fifty varieties, all of them tasty. He was around forty in body age, and probably the same in calendar years. He had been the chief ecologist from the outset, which would have made him about twenty when we started, so he must have been extremely bright to hold such a position at such a young age. Which meant he had probably never had to go into a black bubble. He was too valuable.

“Let’s resume, then,” Travis said, a little testily, I thought.

“Until recently, most people thought the rogue ship had gone out with the first wave. It was about twenty years from the beginning of the first wave of exploration until the arrival of the killer ship. Plenty of time for at least fifty ships that went out in that direction to get there and come back.

“So. The
Mejd Allah
. The billionaires who funded it said they were subscribing to a theory—I don’t know who proposed it—that the problem was that these other ships were spending too much time in interstellar space. They theorized that there was something out there, something that wasn’t in planetary systems, that was killing the crews. They thought it was akin to the situation even in the solar system, where if you spend too much time in a badly shielded spaceship, the dose of radiation you get will sicken you and eventually kill you. They didn’t know what it was, it was just some hypothetical ‘something,’ but the key to surviving it was to minimize your time between the stars. Maybe they believed this theory, maybe they didn’t. Whatever, it gave them a good excuse to do what they planned to do, anyway, which was boost at a higher gee than anyone ever had before.