Mirikami asked, “How small of a mass are you considering, and how close will it be to the rod?”
“It’s small enough and massive enough to produce a tiny black hole at the scale we need, but too low of a total mass to significantly attract objects more than a hand span away. It is mass energy in a very small package, but not massive enough to affect the rest of the ship. Being a mini black hole is why we can’t let it touch the sides of the launcher or the end of the projectile, or it would eat groves in our tube and destroy the tip of the rod. That isn’t a problem, not with the atomic level of precision we can use to position the focal point of the gravity field, when it’s physically close to the projectors.”
“OK, so I presume you put the mass of a mountain in your black hole, but that’s not a lot of attraction. I’ve walked on ten-mile-wide asteroids, and a hard toe tap could have put me in orbit.”
“The mass of an even larger asteroid is more like what we use, but as you say, not a lot of attraction, since you could easily fly off its surface if you flexed your foot too hard. In Haven’s gravity, such a mass held a foot over your head would only lift your hair against Haven’s thousands of miles more remote center of gravity. Distance is again the key.”
Trying to be patient, Mirikami reminded them. “I arrived here late because of the visit to the gene labs. I’m not regaining any of that lost time.”
Blue spoke faster. “We can place that mini black hole’s event horizon an atom’s width from the end of the rod. As the rod is attracted to it, the AI will shift the gravitational focal point ahead of the rod’s movement. The acceleration is continuous, there is no back reaction from a thrust on the rod because we are not pushing against its mass. It is essentially in free fall towards that strong gravitational focal point, with the ship’s gravity being insignificant.
“The acceleration of gravity is directly proportional to the mass, and inversely proportional to the distance squared.” He wrote the formula on a wall screen, of g=G*M/R^2.
“If we reduce a given separation distance, R, in half, the resulting acceleration is four times higher. We maintain the separation between the rod and the black hole at about the width of a hydrogen atom, so the acceleration is large even though the mass isn’t stellar in scale, and we keep moving the black hole ahead of the rod via our gravity projectors, using the immense tachyon power available to us. We are stealing some small measure of that energy to move the rod, magnifying the effect for the weak force of gravity.
“It’s advantageous because we have unlimited energy which we can control precisely, the launch has no back reaction on the ship, the rod’s speed makes it all but undetectable when fired, and using our gravity projectors, it can change course as it accelerates away, making it hard to detect, and nearly impossible to hit. It probably can’t be traced back to the invisible small ship where it originated if we curve its course slightly as it accelerates, at an ever increasing rate.”
“How does it keep accelerating, and receive steering?” Mirikami wondered.
Once the rod clears the launcher, and pulls a safe distance from the ship, we can greatly increase the tachyon energy fed into the gravitational field, increasing the effective mass of the mini black hole, and the acceleration will increase dramatically. We gradually increase the event horizon’s spacing ahead of the rod with increasing distance, due to focusing uncertainty with greater range, but we think we can achieve a significant fraction of the velocity of light within a few miles, one percent, or a bit more.”
“You mean over a thousand eight-hundred miles per second? What’s the rod made of? If it’s dense and heavy, it would pulverize whatever it stuck, or punch straight through.”
“We made them from a steel and tungsten alloy for toughness, tapered at both ends with a lonsdaleite sheath around the entire thing for hardness, since it can be launched in either direction. We are calling them gravrods, to distinguish them from different types of rods for other purposes.”
“I guess toughness helps it penetrate. What is that hard glass coating? Long daylight is what it sounded like you said.”
Coldar corrected him. “The name is lonsdaleite. I researched Torki and Raspani databases, asked the Prada elders for their memories, and dug through human technical libraries. Lonsdaleite is an unusual form of carbon that never forms in quantity, or in a pure form in nature. It’s sometimes called hexagonal diamond, which is about 58% harder than cubic diamond on one face of that crystal form. It can resist indentation pressures of 152 of the units your physics calls gigapascals, or GPa. This compares to the cubic diamond crystal, of the gem stone variety, which breaks at 97 GPa.
“Microscopic crystals of lonsdaleite are often formed from carbon embedded in asteroids that create large impact craters, but the crystals have many defects and impurities that weaken them. The Raspani discovered a chemical vapor deposition method, using their fifth-force boring tool to breakdown pure carbon molecules, while they are being held in a powerful magnetic field arrangement, to build up pure hexagonal crystals on a substrate. That gas deposition method was able to coat our tungsten-steel alloy rod with a thin crystal shell in several minutes. However, I believe you misunderstand the reason for the toughness of these gravrods. A flat plate made of water ice, with the same mass and velocity would be just as damaging, but we couldn’t launch something that fragile using this method.”
Mirikami grimaced. “That’s hardly the first misconception I’ve suffered through today. Tell me why the rods toughness, hard surface, and pointy ends aren’t needed for penetrating the target.”
“The projectile needs to hold together at whichever sharply pointed end is closest to the event horizon. The gravrods must resist the extremely high gravitational attraction, which might otherwise elongate the tips if they were allowed to stretch towards the edge of the extremely close mini black hole. The tough metal and that rigid hard coating helps hold the rod’s shape, and keeps the tips attached to the widening rod behind them, preventing the projectile from pulling apart.
“I suspect a Spacer will have heard the word spaghettification in discussions about what happens to objects falling into a black hole. Near a black hole the tidal forces are so powerful that no object can resist being deformed, no matter how strong its components. We maintain the position of our mini black hole just beyond where that effect would become irresistible for the rod, but close enough that the acceleration is high. A stronger rod allows that distance to be microscopically shorter. Once the rod’s velocity is great enough, it could strike the target sideways and still do enormous damage.”
Mirikami nodded. “I’ll accept your assurance that it will work, but I have to see it in operation to best judge how we can use it in combat. What level of damage could you predict for an impact on something like a Ravager, which is the standard Ragnar space combat ship, close in capability to a clanship in firepower, and which has an ability to take considerable damage?”
Blue said casually, “A hit on the nose or tail, directly in line with the central axis, might possibly kill everyone inside, and rupture their fusion bottles, primarily from the conical spray of ultrahigh velocity vaporized gases and molten metal debris from the point of contact. I doubt if four gravrods would be enough to kill all of the personnel aboard a Smasher, because it has a pyramidal design with a four-axis structure. If you managed to launch a rod into a side, reaching their deeply buried central fusion generators, that explosion might destroy the vessel from the center, in one or two shots.”
Mirikami wanted to make certain he’d heard Blue correctly. “A Ravager destroyed with one shot, and a Smasher gone or disabled using two of the four shots available in a single magazine for a Scout?”
“We believe that is possible, if you carefully target the enemy ships.” Coldar confirmed. “The operational magazines will hold ten gravrods for a Scout.”
Mirikami idly scratched at his itchy rump, his mouth stretched wide and showing white teeth. Blue had to remind himself that in a human, this
wasn’t the Raspani frown of deep disapproval, that the captain was actually quite pleased, despite the opposite seeming expression.
“My sincere thanks to you Blue, and to you too Coldar. I no longer consider my day to have fallen several hours behind schedule. In fact, I’m days ahead of where I thought I would be by now.”
****
Starting his mission had actually taken more than the few days Mirikami felt he’d saved on that one productive afternoon. Because the results were promising, he’d postponed his and Maggi’s mission into the Empire to test Scout ship performance. The mission had expanded to five Scout ships, and it was delayed for two weeks. That was to complete the cuttlefish skin mod for the twenty Kobani going along, and to install and then live test the gravity guns on each of the small ships.
The gunnery test was accomplished in a nearby elderly stellar system, which harbored no exploitable rocky planets. There were three giant planets, a hot Jupiter with an orbital period of only two days around the small red M class star, and two Neptune sized planets. One was an ice giant, like its namesake, and orbiting in the cold outer region. The third was a similar size world, but had a bloated atmosphere because it was well inside the narrow goldilocks zone for the dim old star. The ices from its long ago formation in the outer system having been evaporated by billions of years residing in an orbit with a “year” lasting nine days. It had interacted over eons with the original planetary disk, and had long ago migrated inwards. It now was the shepherd of millions of asteroids in a heavily populated band located between it and the largest planet. That was their “shooting gallery.”
Maggi took her last shot at a behemoth asteroid in the belt, a dwarf planet that was nearly six hundred miles in diameter. She launched her projectile from the rear of the Scout at nearly a million miles’ distance, and instructed her AI, Charles, to accelerate the rod only as long as it could do so effectively.
The AI told her, “Mam, distance to impact is about forty thousand miles, and the lag time for adjusting the focal point is too great for continued precision acceleration or guidance. I have rotated the black hole into Tachyon Space.” It ended its words with, “Estimated impact is now.”
The final words had required only fifteen seconds from the start of the announcement to the estimated impact. From forty thousand miles to contact, meant the rod must have achieved a velocity of around two thousand six-hundred miles per second. The exact velocity could be calculated more precisely later, but this test had defined the approximate distance from which precision placement of the gravitational focal point could reliably be maintained ahead of the projectile.
Sarge had tried a similar shot from double that range, and had aimed at the same crater on the same asteroid. His rod had come too close to the growing event horizon and had vanished from the universe before reaching the target.
Just over five seconds later, the visual evidence of the successful impact of Maggi’s shot arrived at the velocity of light. It was a surprisingly small flash of blue-white light and a smaller plume of debris than expected. It hit a half mile from the rim of the one-mile wide crater selected as their bullseye. The result on the far side of the spherical body was considerably greater. A miles wide circular region on the surface rock and ice mixture, of the unnamed dwarf world, bulged up by hundreds of feet. The lightest dusty material reacted stronger to the shock transmitted through the differentiated rocky core, and would either reach escape velocity, or perhaps form a set of future rings around the little world.
“Hah!” Sarge gloated over Comtap. “You couldn’t put it in the hole. If my AI hadn’t let the event horizon get so close to my shot, I’ll bet I’d have done better. I was on-target when I launched, from twice as far away as you.” He’d been trying to boost velocity by telling the AI to increase the black hole’s mass and to keep it close to his projectile over a greater distance.
Maggi retorted with a snort of humor. “You sure brag a lot for a man that shoots blanks, from a gun that’s too short.”
Mirikami prevented additional devolution of their usual wordplay. “I think we know enough about the limits of accuracy and range for the gravity guns. If we’re aiming at something large, like a moon base, we can probably hit that at a half million miles. However, as we just saw, it might be better to strike from the opposite side, if the base is on a small moon. The shock wave would probably ruin their day more thoroughly than a direct strike would.
“The small ship sized asteroids that we hit completely blew out the opposite side, and they fragmented from the internal explosive heating. Those precise hits proved what we anticipated; that we need to get closer to enemy ships or orbital platforms for the best targeting. I don’t think many warships can survive hits by these gravrods. They’ll need to step up laser defenses a great deal in order to have a hope of stopping them.
Dillon asked, “Tet, does this mean you think we’re ready to head into the Empire to give the Thandol reasons to delay their next attack? Or will we make a trip back to Koban to pick up more new Scouts, for a larger raid?”
“We haven’t proven that the Empire tachyon wake monitors can’t detect us at T-squared or T-cubed travel. I don't want to risk more Scouts before we know. Hell, I don't want to risk these, but we have to know.
“Before Maggi and I split off to visit Canji Mot and Canji Dol, and place the Hothor and Olt’kitapi at risk again, we need to hurt the Thandol bad, and make certain they aren’t able to track us, even when they’re really pissed off. Our own detectors can’t pick our slight wakes out of the noise background of random events in Tachyon Space, even if we know when a Scout passed by. That doesn’t mean their monitors can’t do that, and they’ve been at it for a long time, with races that want to move about unnoticed. We’ll go to Wendal via five different routes, with no attempted subterfuge this time, and find out if they react to us, as I’d expect if they detect us. Especially after our two previous kick-ass visits.”
“Are we going to go after the Emperor, if he’s in his big ass palace?” Thad had asked this earlier, receiving an inconclusive answer because the gravity guns needed testing. It was a move he supported, along with Sarge and Sergey Medlov, the latter sharing a Scout with his new wife, Carol Slobovic. The three men thought cutting off the head of the Empire would throw the Thandol into chaos, delaying their plans for taking on the Federation.
Maggi was the spoiler of that plan. “No. Killing the top politician might be chaotic in the PU, and perhaps for our fledgling government, because it would be unprecedented, and we aren’t accustomed to something like that. The Empire has literally had a hundred or more emperors killed and replaced, and they have processes to keep the Thandol rule of law in place over the rest of the empire, even as there is a narrow and limited struggle for the top leadership spot.
“However, it is chaotic and distracting, when there is a developing coup discovered in advance, and the present Emperor has a chance to thwart his opposition. The history we asked the Hothor to share with us, through the Olt’kitapi passing the stories along to their Dismantler AIs, describes behind the scenes panic in past Imperial Courts. Yet, in those cases, the outward face of the Empire was steady, and they were firmly in control of the other races.
“The Emperor typically becomes preoccupied with recruiting support from his own and other noble families, to promise, or even to grant immediate rewards and greater power sharing with them. That’s normally done face to face, or trunk to trunk in this case, traveling to meet with those they need to influence. The Emperor and his closest aids often become too preoccupied to worry about events outside of the Imperial Court. They won’t entirely trust their own military, if someone there is a high-ranking potential rival.
“As soon as the preoccupation with a coup subsides, with a new Emperor, or the old one still in power, that particular leader needs to prove they have a tight hold on government. They will do something to strengthen their hold on power, like annex a new species if one has been discovered recently, or raise taxe
s to pay benefits to those that backed the winner. Annexing us would accomplish both goals, so we have to prevent that.
“I intend to start a rumor there’s a coup planned, chose someone in the Thandol military heirarchy to be the patsy, and divert the Emperor’s plans against us by preventing the High Command from gathering a large fleet. He will be goaded into fearing the fleet could be turned against him.
“Simultaneously, we will try to stir up a revolt against the Thandol, or perhaps more than one, by their security forces. Or at least convince the Emperor that there are revolts developing, even if there are not. He won’t trust his own navy, and he’ll hesitate to let his security forces mobilize for attacks against us, because they might take advantage of his own weakness. We should gain time to grow stronger, and to convince the PU to form an alliance with us.”
She concluded. “It simply isn’t to our advantage to kill that wormy damned Emperor. In fact, I learned from our two captives about a debilitating parasitic alien gut worm, to which the Thandol are susceptible, and current drugs are not very effective. It’s not a fatal affliction, but damned if I won’t find a way to place some of the eggs in his personal browsing plots, inside the palace. He shares these with his favored females, and visiting nobles. He’ll be ankle deep from his own runny bowels while he fights a fictitious coup, and worries about revolts.”
Mirikami shared a self-fabricated image of himself with a lopsided smile. “With that pleasant bit of sabotage to soil our minds before dinner, every Scout should plot your own course to Wendal; to arrive roughly a million miles out of the planetary plane in three days, above the planet’s north pole as your reference. We Jump in five minutes.”
Koban 6: Conflict and Empire Page 37