Scattered Defenses

“Water you doing?”

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After the first barrage, I saw the turrets swivel under newly activated AI control, and a torrent of violet plasma flow over the hull and harden against the crushing force of two opposing magnetic fields into a seething conflagration that crackled and sputtered pink fire.

Of the latter, the so-called “plasma window” had previously found use in electron-beam welding applications. Alone, it would stop nothing. But it would (mostly) hold an atmosphere. Great canisters along the ship’s broadside had slid open, exposing their contents to hard vacuum. The precious water within, ordinarily used for remass, was furiously boiling.

The next volley struck then, and even from the emergency redoubt, nestled deep within the ship’s interior, I felt the lurch as the cargo bay was gutted by a spinal-mount ray, even as I saw it burn cruelly in a visiplate.

But the steam and ice had by now fully formed, resublimating and desublimating into each other as crystals danced in the flames, and upon the third volley, their pencil-thin near-IR laser chewed into the mixture, and was absorbed and scattered by it. The hull amidships smoldered worrisomely in a wide circle, but it held.

To sustain one atmosphere in a plasma window requires a bit shy of 20 megawatts per square meter. But you can get away with a thousandth that if you settle for holding less pressure. Even so, banks of hydrogen batteries were rapidly discharging in an internal struggle the ship’s twin reactors would quickly lose. The ad-hoc shields could stay up for less than a minute, perhaps, before waste heat and power requirements forced them to drop.

Excerpt from “Farside Encounter”; collected in the anthology Tall Tales of Trade, 49.95

Forward Euler

In your honor, Baraff and Witkin.

“One of our major problems is scalability. Exponential growth still works, so no matter how much simspace or compute you have, it all fills up pretty quickly.”

“How bad?”

“For quality-of-life reasons, we need to simulate physics at 10-1m (down to as small as 10-4m near simpersons). The teeming masses want to interact with the real world, meaning time must be simulated more-or-less 1:1 with reality. Now multiply those requirements over a km3 of simspace and think about those numbers a minute.”

“You cut corners?”

“Obviously. Δt is 25 ms, and the engines use forward-Euler numeric integration.”

“Hold up. FE doesn’t work. The numerics pump phantom energy into your reality. If a deer steps in a forest, that footstep gradually becomes a nuclear holocaust engulfing the universe. No bueno.”

“Well no shit. So we remove the pent-up numeric barf once every thirty seconds with artificial damping. That’s why there’s a little hiccup in the universe’s framerate twice a minute.”

“Don’t the customers complain?”

“Yes.”

Artificial Gravity

Highest bidder loses.

“Why can’t we design in a rotating ring?”

“Because think about the bearing. The entire circumference of the fuselage must be sealed–a seal which, by the way, must be both absolutely airtight and operational for years on end, at minimum.”

“The seal doesn’t have to be on the inside of the habitat.”

“Well, then you have to EVA every time you want to go anywhere else in the ship. No one’s really figured out a great material to resist vacuum welding either. If it happens anywhere and that bearing seizes up . . . well. Best case, you dump your precious, life-giving atmosphere into space and everyone dies. Worst case, any habitat worth having has enough momentum to wrench the ship in twain–so everyone dies, and the ship isn’t even worth salvaging afterward.”

Best case, you dump your precious, life-giving atmosphere into space and everyone dies.

“Well, why can’t we spin the whole ship?”

“That turns null-g into micro-g, complicates docking and navigation, and confuses the hell out of your pets. And you still need to get that spin in the first place–what a horrid waste of mass. We only bother for stations, because we only need to do it once.”

“What a delightful mélange of engineering and physics.”

“Yeah. Mag-boots are clumsy, but at least they won’t kill everyone.”

Fan

Can missiles wear lead aprons?

Modern battles are fought at close range–a light-second or so–since lasers are big, heavy, slow, and radiate more than half their power into their parent ships as low-quality waste heat. That’s why every conflict since the 2110s has been fought with missiles and k-slugs.

The danger with missiles is that they’re fast and independently targeted. Try shooting them down with a gun of some type and you have a problem: the missile has traveled literally miles before your bullet gets halfway down the barrel.

Particle beam weaponry was once largely considered to be useless. About the best it can do is barf up some bremsstrahlung secondary radiation. Deliciously lethal, sure, but only in a localized area, and certainly not structurally damaging. The engineer-physicists eventually realized, however, that the particle beam is well-suited to defense. And so, the fan was invented.

The fan makes use of an otherwise annoying property of particle beams. When you deflect a stream of charged particles, you’re accelerating it, but the stream still goes basically the same speed afterward (just in a different direction). That extra energy gets dumped in the form of synchrotron radiation, streaming out tangentially in a flood of hard x-rays. So you get a searing fan of radiation, spreading knifelike in a plane.

Nowadays, when the call goes out for point defense, the ship fires up its spinal-mount linear accelerator. Huge flickering electromagnets in the bow deflect the beam semi-randomly, and a decollaminated blast of bit-flipping, electronics-frying radiation cooks the missiles as they reach the terminal guidance phase.

Small wonder the Jovian Trade Union’s radiation hardening expertise is widely-sought.

Annihilator Station

No, we are not compensating for something.

During the apex of the second proto-galactic empire, spanning from approx CE 14200 to CE 14500 (before it was subsumed into the current galactic empire), great monuments of engineering were fabricated in a stupendous display of that same society’s decadence.

Annihilator Station–a name chosen, amusingly, by a third grader from the Alnilim system in a contest–provides an illustrative example.


A.S. was envisioned as a defense system for an entire solar system–specifically, the Centauri system containing the Empire’s capital. (No one was quite sure who the enemy was, but this small matter demonstrates the cavalier and bold attitude which characterized the proto-empire at peak.)

In all dimensions, A.S. was enormous. The main structure itself was built around a composite laser, whose primary bore was fully 2,000 km in diameter. The focusing system alone massed as much as Ireland. Since rotating the structure (and so the main beam itself) into an arbitrary alignment could require as long as a month, the main bore could be tapped to power secondary laser batteries–more mobile, practical laser turrets whose diameters ranged from 10 m (at the extreme lower end), up to 100 km (of which there were 10) or 50 km (of which there were 471).

It was literally the case that the combined fleets (at that time) of all interstellar nations, if put side-by-side, top-to-bottom, arranged broadside, could not cover even a tenth of that enormous aperture. The device was therefore capable of obliterating, in a single shot, the sum total of all militaries that at that time existed. For that matter, it could irradiate all of a large moon’s surface simultaneously, or cause a gas giant to combust.

The power requirement was, literally, astronomical. Just to keep the lights and life support on, A.S. burnt a (combined) mass of Plutonium the size of Gibraltar every year. The thing leaked enough air out from between atoms of its 500 m-thick hull that it had to be replenished by regular shipment. Of course, it had non-negligible gravity at its surface, too, and so keeping the lenses free of any stray, diffracting atmosphere provided employment to over 10,000,000.


In the end, the threat A.S. had been built to counter never materialized, and the station was ultimately done in by an equal mixture of logistics and intrigue.

One unfortunate fact of military operation is the necessity of hierarchy–particularly, a chain of command. Therefore, for any operation of any scope, there’s always someone in charge–maybe with advisers, but ultimately still one guy.

In this case, that guy was Grand Admiral Juiykla Hvvghinchych.

The Admiral was fond of booze and women, and, being the direct administrator of the largest military operation in history, found that he could rather simply arrange them, polity be damned. One of his consorts was a woman named Symotrishia Kavan. Ms. Kavan was connected, obliquely, to a curator of the Museum of Gambling, located on the sixth planet of the Centauris. This curator was in direct correspondence with the criminal underground, which of course was sympathetic to piracy.

Piracy, post-21st century, invariably (and necessarily) involved hit-and-run tactics. Commodity pricing on local stargates and reservations booked in advance made effective pursuit by law-enforcement all but impossible–clientele personal information, of course, being thoroughly encrypted.

The looming spectre of A.S. was a threat to piracy. Just aim one of the kilometer-wide auxiliary beams across the stargate. Ain’t nothing getting around, past, or otherwise through, that.

And so it was that the curator was smuggled four antimatter weapons, each in the 80 MT yield range, and Ms. Kavan, ah . . . convinced the good Admiral to allow the personal gift of fine whiskey to pass through customs unexamined.

The devices were detonated in the structural members near the power-generation compartments. Plenty of secondary damage was caused, including a firestorm of venting atmosphere that swept a full eightieth of the station. For her part, Ms. Kavan is believed to have perished in the blast. The Admiral himself committed suicide less than an hour after the incident. The curator was to be held for conspiracy, but died while attempting to escape–his hastily departing yacht disintegrating shortly before max-Q.

Ultimately, the structural damage to A.S. was minor–after all, a few nukes going off inside a structure the size of a small continent could almost be ignored, and the power areas, which suffered a secondary nuclear conflagration, could still be rebuilt rather simply.

Unfortunately for A.S., the bombs were the sociological straw that broke the proverbial camel’s back. The workers’ union struck, and–coupled with the already extant logistical nightmare of keeping a billion people in low-G supplied with food, water, entertainment, living quarters, and pay–caused a complete and almost instant collapse of order. The workers refused, in fact, go out to meet the cargo ships that would have brought them food. By the time the prospect of famine was upon them, it was far too late. Even moving a million people per ship was not fast enough. And so, hundreds of millions perished in the steel hallways of the greatest weapon in the galaxy. The government public-relations catastrophe alone caused, indirectly, several genocides, four planetary-scale secessions, and a new religion.

Under the circumstances, A.S. was abandoned to ruin in its own orbit.

Unintended Consequences

I don’t get along with myself.

The greatest feat of astroengineering yet devised is the energy bridge. Picture a woman in a long, trailing dress. Suddenly, she grabs handfuls of cloth and reels in the train, compressing the cloth into folds. This says something of how the device works, only the woman is really a-battery-of-suns-in-a-Dyson-sphere-swarm and the dress is really the-fabric-of-space-time-itself.

The effect of the untold quadrillions of dollars invested by the U.F.P. is that you can point the gymbaled attractor in any spherical direction, and reel in that section of space like so much whole cloth. Then your puny spaceship can jet across on last-millennium’s NERVAs. Interstellar travel of practically infinite distance, faster than light.

A problem for Physics? Absolutely. In fact, there were some comic chronological capers involving the project director himself and his own daughter, which are too bawdy for official channels. Suffice to say, the universe doesn’t give a pulsar’s ass about self-consistency, and chronopol had its work cut out for it determining such issues as what timeline should be used for claims of statutory rape, and whether it’s legal to steal money from yourself.

The Shield

Remember Timmy, with great energy
comes great relativistic confusion.

The pinch-field generator operates on the same principle as a black hole.

Matter makes light bend. The mechanism isn’t really light bending, per-se, so much as space bending around it. So the light travels a straight line in curved space, and it only looks like it bends.

Well, it turns out mass and energy are really the same thing. This gave an engineer an idea. And his son the same idea. And in turn his twin daughters the same idea, and one of their sons the same idea, and his son the same idea, and so on for a dozen or so generations until one of the line of engineers finally succeeded, and vague speculations became ultra-secret, classified military projects. See, with a bit of trickery, energy can be made to distort space too. And by rerouting that energy, you can change the effect, in a manner impossible with ordinary matter.

Why you hitting yourself?

The basic idea is to create, preferably as far from your ship as possible, a grid of superconducting cables, then dump energy into them. Like, a lot of energy. Like, the-total-output-of-the-sun-for-a-year kind of energy. But, with Dyson spheres around a hundred or so stars, the first fully functional ship sporting a pinch-field generator was completed in the 19th year of the Human-Tassad war.


The first encounter is worthy of note. At 7550-12-12 04:07 EST, the Tassad battlecruiser opened fire with starboard laser batteries 45 through 97 at a range of 17 light-seconds and nearly zero relative velocity. The U.F.P. Dauntless, sensors tripping at the sudden heat flux, automatically deployed the pinch-field’s incomprehensible energy from the central core of the ship, out into the far distant material of the shield.

As the night watch in the Dauntless was thrown unceremoniously into null-G, to a distant observer, the Dauntless appeared to disappear in an instant. But look closely, and you could see that the area where the shield had been now appeared a reflection–a cosmic mirror.

In truth, what had happened was the light now bent through 180 degrees, while still traveling in a straight line. But, unlike any physical mirror, no fractional percentage of light was absorbed by any material. No weakness existed. In fact, any material object nearby, save the exquisitely balanced shield cables themselves, would be torn asunder by tidal forces almost instantly. Invulnerable.

The titanic blast from the 53 Tassad laser batteries came to bear on the pinch-field, and were promptly and utterly harmlessly rotated through twisted space, 180 degrees in heading. Thereupon, the fiery lasers of the Tassad battlecruiser demonstrated the meaning of that ageless playground taunt: “Why you hitting yourself?”


The Human-Tassad War ended tidily in the 20th year.