Nova Roma: consequences of sundiving and stutterwarp

[Adam Dray]

Yeah, I just realized the black=absorptive thing and was on my way back to correct it. Let's say that gravity does weird things to space around the bubble, but it's still not a point mass.

The bubble is required to use the hackdrive at all. That is, the bubble creates the inertialess frame that the hackdrive moves through space. The bubble has to be up for there to be motion.

 

[McPerth]

Wow, I hadn't considered the military strategy of this. Wow. How do you even counteract this? Is it basically an Omaha Beach scenario every time you invade a starship-capable system that doesn't want you there?

More or less, but without the air and naval bombing support from your fleet and air force...

As said, that's not unlike traying to do it in Imperial Starfire, and I remember what a nightmare that was...

I think piracy is something that happens between the star and its system, right? Space is big. If you're three days from a planet, there might not be any kind of lane cruiser within a day or two of you when the pirates hit you.

But the times to travel are shorter (sun is 8 LM from earth, so probably a ship can be at Earth orbit in 2 hours from the sungate, and its a more or less narrow straight line for the fleet to patrol, not a sphere arround each body where a ship can emerge from jump in OTU.

Of course, detection is probably much harder than in CT. As far as I can tell, CT assumes that detection is impossible to avoid at almost any distance within system. Wrap a black globe around your ship, and that changes.

Detection of ships appearing from near the sun will probably pose problems (more so when you have to flicker your bouble to allow them to see, if I understood you right), but the ones emerging would not be in a better position, and lowering the bouble would be more dangerous for them, being closer to the star.

Probably there would be automated sensor "buoys" pointed to each sungate, relaying for it if they have to use the bouble too protect themselves and cool.

The wormholes are 1km across and uni-directional. Travel through them is instantaneous. There's no danger of collision, I think.

The wormholes are really just folds in space from star to star. There's no real distance between them. They don't have a capacity, so any number of ships could enter at the same time, assuming they don't collide in real space. I think a sungate could be as busy as a modern airport runway.

I disagree about the range of collision:

at 0.1 c one km is nothing, and with the sensors downgraded due to the bouble and the last 3 LS (30 seconds at 0.1 c, so about a million km effectively blind) it's already a true feat they hit the sungate (to put it to scale, is like hitting 1 mm from 1 km), I think is too much to ask them to avoid collisions too...

It does sound familiar! I have never even heard of this game. It sounds like it might be something useful to simulate starship battles for my universe, though, with a couple mods! Thanks for the pointer.

You're wellcome. Frankly, I'm not sure if it's still in print

Yeah, I think they'd want to stagger them for safety.

At the same time, I think they'd want to get them through, as many as possible, quickly. This is the counter to the Omaha Beach scenario of having a blockade of starships or missile batteries waiting on the other side. It feels like the only reasonable way to invade a system is to rush a whole lot of ships through at once and overwhelm the defenses.

Off course, military actions are always in diferent safety margin that civilian ones, like the flying (and taking off) in formation, to keep the analogy of a runway.

The first ships through are probably unmanned decoys. Expensive, 200 MCr decoys. Ow.

That would be met by the mines I told in the addenda...

 

[Adam Dray]

But the times to travel are shorter (sun is 8 LM from earth, so probably a ship can be ar Earth orbit in 2 hours from the sungate, and its a more or less narrow straight line for the fleet to patrol, not a sphere arround each body where a ship can emerge from jump in OTU.

Oh f***. I did some math incorrectly somewhere. I had chosen the 0.1c figure to force a 6-day travel time. Instead, I created a 80-minute travel time. That won't do. Uh, 0.0009c top speed? <=)

Did you know that you can type "convert 1 au to light minutes" into Google (without the quotes) and it will tell you "8.3167464 light minutes"? Works with almost any units as long as you start with "convert".

Detection of ships appearing from near the sun will probably pose problems (more so when you have to flicker your bouble to allow them to see, if I understood you right), but the ones emerging would not be in a better position, and lowering the bouble would be more dangerous for them, being closer to the star.

Probably there would be automated sensor "buoys" pointed to each sungate, relaying for it if they have to use the bouble too protect themselves and cool.

Yeah, agreed. I'd set up a robotic system that would attack anything that came through the gate and failed to send the "I'm friendly" code. Also relay data back to the defense force as things came through, in case of a mass attack. I'd surround the area with thousands of guided missiles that could be turned on with a signal.

I disagree about the range of collision:

at 0.1 c one km is nothing, and with the sensors downgraded due to the bouble and the last 3 LS (30 seconds at 0.1 c, so about a million km effectively blind) it's already a true feat they hit the sungate (to put it to scale, is like hitting 1 mm from 1 km), I think is too much to ask them to avoid collisions too...

Does it change if the starship can make 90-degree angle, even 180-degree angle, turns, and has computer-assisted guidance? Because that's how it works. It has the equivalent of a missile system for guidance (with human override in case of the unexpected) and the hackdrive movement isn't like a rocket's with all that troublesome momentum. It's essentially an inertialess system moving around space like it's in a video game.

Maybe it's still hard to hit a 1 km, moving target on the surface of the sun. I don't know. I've never tried it and I'm not a rocket scientist. I do know that missiles hit pretty small targets (today) from crazy far distances at incredible speeds.

And that 0.1c speed probably has to be 0.0001c for everything else to work (or at least be interesting). I really can't let travel be that fast for the game play to be fun. It's gonna have to take a week to travel 1 AU. That's 67,000 mph (108,000 kph), which is apparently less than half the maximum speed of Helios 2.

Thanks for all your comments! They're really helpful.

 

[Carlobrand]

I am confused. Your hackdrive moves your ship, but you do not gain momentum. In traveling from a distant point to a point close to the sun, you travel from a region of high potential energy to a region of low potential energy. Translating into English, you fall: you are moving deeper into the gravity well and the potential energy of gravity on the distant object is becoming kinetic energy related to the object's mass and velocity as it falls faster and faster downward. In this hackdrive, you move from a region of high potential energy to a region of low potential energy by apparently displacing from one point to another rather than physically moving - but you end with no velocity.

Mass/Energy can neither be created nor destroyed. I will assume that some feature of the hackdrive conserves energy, because it must or it violates a fundamental law of the universe. In other words, as you change position from a higher point in the gravity well to a lower point, what would otherwise be your kinetic energy of motion is instead being expressed as some other form of energy, possibly light: the hack drive glows in infrared as it releases energy gained from changing position in the gravity well, leaving the ship inside with no change in velocity when the hack drive flickers off.

Here's the real trick, though: to accomplish that, your hack drive must perfectly shield your ship from the universe during the phase in which it is moving/displacing. External gravity cannot affect the ship: it must interact with the hackdrive field instead. That, or your ship itself will start heating - and I don't think you want to go there 'cause you're already struggling with the heat thing and I'm thinking that descending toward the sun at a rate that allows the ship itself to safely discharge that heat would be a rather long process. Better for the hackdrive field to go glowing and releasing that heat. However, if your hackdrive field is capable of isolating your ship from the universe to the extent that gravity does not affect it, then it is unlikely that any other force is going to be able to cross that barrier. It is a perfect shield.

Another issue is conservation of momentum. Let's say you are at Earth and decide to drop down to some point near the sun. Your hack drive allows you to move without gaining momentum - but you still have the momentum you had at the point where you turned the thing on, back at Earth's orbit.

Put another way: Earth whips around the sun at about 67 thousand miles per hour. Mercury whips around the sun at almost 108 thousand miles per hour. Something closer still to the sun would have to move even faster to maintain a stable orbit. Back when you were at earth orbit, you were stable with respect to the sun, moving at 67 thousand miles per hour right along with the Earth; you didn't notice you were moving 'cause Earth was moving right along with you.

Now, at Mercury's orbit, you are still moving 67 thousand miles per hour, but it's nowhere near fast enough to maintain an orbit: the instant you turn off the field, you start falling sunward like a rock. In fact, every time you blinked the field off while on the way here, you started falling a bit, gradually accumulating more and more downward velocity. Moreover, an object in a stable orbit near Mercury is flying 41 thousand miles per hour with respect to you (his 108 thousand minus your 67 thousand), and an object in a stable orbit farther in is flying even faster. You are in essence a falling rock trying to catch a ride on a passing hypersonic jet.

 

[Adam Dray]

I am confused. Your hackdrive moves your ship, but you do not gain momentum. In traveling from a distant point to a point close to the sun, you travel from a region of high potential energy to a region of low potential energy.

Let me rephrase that in terms of Nova Roma science.

In traveling from a distant point to a point close to the sun in Universe A, you travel in Universe A from a region of high potential energy to a region of low potential energy, but the entire time, your ship is inside a bubble called Universe B. There is a shadow of your bubble in Universe A, but it's more of a distortion of the fabric of space and it is massless. Gravity does not affect it, nor does Universe B gain momentum in Universe A.

If the ship were to turn off the bubble, it would start to gain momentum and move toward the center of the Sun's gravity well. In fact, this happens whenever the ship drops the bubble for 100 ms to get a sensor reading.

The potential energy that the ship gains must be accounted for when the bubble is turned back on. The total mass (including gravity potential and other energy) work against the machine that creates the bubble. That is, it's harder to pull the ship out of Universe A back into Universe B because of the additional energy it has picked up from the gravity well. It's still fairly small due to the short duration.

I realize now that I'm totally ignoring curved space and general relativity. If the hack drive simply translates the bubble through normal space, then it is subject to gravity because gravity is just space curvature. However, I still think that the ship would not "fall" in a gravity well like a normal ship in Universe A because it is not actually IN Universe A. If it wants to move in Universe A, though, it must travel "further" to get out of a gravity well and it travels a "shorter" distance as it goes into a gravity well.

Mass/Energy can neither be created nor destroyed. I will assume that some feature of the hackdrive conserves energy, because it must or it violates a fundamental law of the universe.

Yes, good catch. Both energy and momentum must be conserved.

A ship in the bubble has zero energy or momentum outside the bubble. The bubble itself has zero energy and zero momentum and zero mass in the outside universe. That's just how it works.

As I said above, dropping the bubble for even a short time brings the ship back into the main universe and so it starts gaining momentum as gravity forces apply to it. The increase to momentum is dependent on mass and relative velocity (p=mv). 100 ms is not a lot of time and thus velocity doesn't increase that much (remember, it starts from zero). Still, the ship has to conserve that momentum to bring the bubble back up, and that means an expenditure of reactor drive energy at the time of bubble activation.

Maybe activating the bubble causes a huge flash of energy equal to the total energy of the system being negated. That is, only the momentum is being negated, and perhaps some of the light it gives off, so there's a one-time flash. The rest mass of the ship (and the energy of its reactors, batteries, etc.) inside the bubble continues to be conserved inside the bubble, so no problem there.

In other words, as you change position from a higher point in the gravity well to a lower point, what would otherwise be your kinetic energy of motion is instead being expressed as some other form of energy, possibly light: the hack drive glows in infrared as it releases energy gained from changing position in the gravity well, leaving the ship inside with no change in velocity when the hack drive flickers off.

I don't think that's necessary, since the bubble is not part of the universe where the gravity well is.

Put another way: Earth whips around the sun at about 67 thousand miles per hour. Mercury whips around the sun at almost 108 thousand miles per hour. Something closer still to the sun would have to move even faster to maintain a stable orbit. Back when you were at earth orbit, you were stable with respect to the sun, moving at 67 thousand miles per hour right along with the Earth; you didn't notice you were moving 'cause Earth was moving right along with you.

Now, at Mercury's orbit, you are still moving 67 thousand miles per hour, but it's nowhere near fast enough to maintain an orbit: the instant you turn off the field, you start falling sunward like a rock. In fact, every time you blinked the field off while on the way here, you started falling a bit, gradually accumulating more and more downward velocity. Moreover, an object in a stable orbit near Mercury is flying 41 thousand miles per hour with respect to you (his 108 thousand minus your 67 thousand), and an object in a stable orbit farther in is flying even faster. You are in essence a falling rock trying to catch a ride on a passing hypersonic jet.

No, because you've cheated the universe to move in it. You never actually moved. It's an error in the calculation logic of quantum mechanics that let you jitter your way across space. It doesn't have to conserve momentum in that way. You've merely put yourself in another universe and stayed "at rest" in your bubble the entire time, while the bubble glitches its way around.

 

[Adam Dray]

By the way, Carlobrand, what I didn't say and meant to say is, "OMG, thank you for that post! Challenging the physics the way you did really makes me think about how this stuff works. I appreciate it."

 

[Adam Dray]

Doing some math, I nailed down the transit time for 1 AU: just under 6 days at 0.001c (about 1 million kph).

Sun to Earth = 1 AU = 5.8 days
Sun to Mars = 1.5 AU = 8.6 days
Sun to Jupiter = 5 AU = 28.9 days
Sun to Pluto = 30-49 AU = 173-292 days

Alpha Centauri A to Alpha Centari B = 11-36 AU = 63-208 days

 

[Xerxeskingofking]

what carlobrand is saying is that while the hackdrive can ignore momentum and energy while it's turned on, you still need some method of conventional acceleration and deceleration to match velocities with the target when you turn it off.

to use his examples again: you start in earth orbit, moving, relative to the sun, at 67,000 Mph. you turn on your hackdrive, and move so your next to Mercury. you turn off your hackdrive, to launch a shuttle or whatever.

Mercury is moving, relative to the sun, at 108,000 Mph. With the hackdrive, you have not gained or lost any momentum or energy. so your still moving, relative to the sun, at 67,000 Mph.

Even if you align yourself so your travelling in the right direction, your still moving too slow, and to get into and stay in orbit, you need to use a normal, momentum creating drive to change your momentum. mercury, form your point of view, would shoot off at 41,000 Mph.

when you turn off the hackdrive and start interacting with the normal universe again, you need to start obeying it's laws again. your hackdrive ship, if it turned it's drive off in mercury orbit, would start "falling" towards the Sun, because it's travelling to slowly to orbit at that distance. it doesn't matter that it can stop the fall and reset it's position with the hackdrive. if it wants to stay in orbit and do things, it has to use a non hackdrive propulsion system to speed it up.

 

[HG_B]

what carlobrand is saying is that while the hackdrive can ignore momentum and energy while it's turned on, you still need some method of conventional acceleration and deceleration to match velocities with the target when you turn it off.

Yes. In the Lensman series the ships had to match intrinsic velocity at the end of a journey where they had been using Inertia-less drives. They used reaction drives (or whatever they had).

 

[Adam Dray]

Oh, I get it now.

I don't want to bother with all that velocity matching. I'll say that the process of creating the bubble transfers energy of momentum into the bubble itself. When you drop the bubble, it releases that energy into the local region of space to give you back that momentum (and it's tuneable so you can give it the direction you want).

If that still isn't enough momentum to speed-match the local universe, then the process of dropping the bubble "steals" energy from the gravity well. It wrenches space a bit for a few seconds while things adjust, or the ship can drop the bubble more gradually to minimize local wrenching. Obviously, ships shouldn't do this in close proximity to other vessels or human structures or a planet's surface, as it messes things up badly.

Does that work better?

 

[McPerth]

See that this same problem is on Stutterwarp in 2300AD setting, so I guess we can asume similar actuations (calculating your vector to match with orbital velocity once at place, etc...)

 

[aramis]

To solve the earth to mercury issue...
you drive to mercury. you get inside the hill sphere. You hold in the correct position relative until you have the needed KE vector, then move slightly to enter an orbit, and turn off the drive.

 

[McPerth]

Maybe it's still hard to hit a 1 km, moving target on the surface of the sun. I don't know. I've never tried it and I'm not a rocket scientist. I do know that missiles hit pretty small targets (today) from crazy far distances at incredible speeds.

Sure, but those missiles don't go blind the last 30 seconds of their approach, but guided by them (be them GPS, Radar, IR or whatever they are). Your ships (as I understood you told) go with unreliable sensors while the approach and sensor blind the last 30 seconds.

Doing some math, I nailed down the transit time for 1 AU: just under 6 days at 0.001c (about 1 million kph).

Sun to Earth = 1 AU = 5.8 days
Sun to Mars = 1.5 AU = 8.6 days
Sun to Jupiter = 5 AU = 28.9 days
Sun to Pluto = 30-49 AU = 173-292 days

Alpha Centauri A to Alpha Centari B = 11-36 AU = 63-208 days

Off course, that changes things...

At this speed, the travel sensors blind is about 0.003 ls (or about 8000 km), so the analogy would be to hit a 10 cm target (about the size of a baseball ball) from 800 m. I've no doubt some people may do it, but it's not easy (though they have not the computer support a ship may have)...

See that this also gives more time to the defenders to ready and fire incoming ships before they go out the star influence in their opperations (sensors, gravity well, etc...).

And, regardless of the speed, the main change for piracy is that the path the ships travel through is quite narrow (from star to main planet, or from planet to planet), not the sphere arround the planets, so making it easier to patrol (and I guess any ships leaving those paths would be seen as suspicious, as an airplane leaving the air corridors would be today).

 

[Carlobrand]

...Maybe activating the bubble causes a huge flash of energy equal to the total energy of the system being negated. That is, only the momentum is being negated, and perhaps some of the light it gives off, so there's a one-time flash. The rest mass of the ship (and the energy of its reactors, batteries, etc.) inside the bubble continues to be conserved inside the bubble, so no problem there. ...

And I think that's my point on the conservation of energy bit. Whatever phlebotinum you use to obtain the desired effect, the total amount of energy in the universe itself must stay the same. If you drop down a gravity well, there must be an energy gain evident. If you accomplish that with a flash, great. If you climb up the gravity well, you must give up energy to do it. If you accomplish that by pumping extra energy from your power plant into the hack field, fine. However you do it, it must be done or you present a situation where energy is either appearing in the universe or disappearing from the universe, which cannot occur.

Traveller's classic jump drive arguably violates basic conservation: when you jump from insystem to the outer region, you go from a low potential region to a high potential region. However, the classic jump drive involves a huge expenditure of energy to transition to jump space, and it can be argued that part of the energy expenditure "pays off" that debt.

Oh, I get it now.

I don't want to bother with all that velocity matching. I'll say that the process of creating the bubble transfers energy of momentum into the bubble itself. When you drop the bubble, it releases that energy into the local region of space to give you back that momentum (and it's tuneable so you can give it the direction you want).

If that still isn't enough momentum to speed-match the local universe, then the process of dropping the bubble "steals" energy from the gravity well. It wrenches space a bit for a few seconds while things adjust, or the ship can drop the bubble more gradually to minimize local wrenching. Obviously, ships shouldn't do this in close proximity to other vessels or human structures or a planet's surface, as it messes things up badly.

Does that work better?

It is actually easier to transfer energy of momentum to the pocket universe as a whole than to argue it is not transferred. Just be mindful of your energy budget. If your power plant is putting out X amount of energy, the hack drive cannot make your ship behave as if it has 10X amount of energy or else you're creating energy from nothing. Your ship can be thought of as a mass with kinetic energy. If your hackdrive imparts a velocity of 0.001c - by whatever means - then the kinetic energy of your ship can be found by squaring the velocity and multiplying it by half the mass: KE = 1/2 MV². A reader with a background in physics will look to your power plant and expect them to put out enough energy to equal that during the time in which your hackdrive is imparting the velocity. If it isn't there, they will cry foul: your ship is displaying more energy than it can generate and therefore violating fundamental laws by creating energy from nothing.

In other words, it doesn't matter how you bring the ship to 0.001c. What matters is that you show your ship producing enough energy to pay for that privilege.

Now I present to you a combat challenge. A ship is able to move at 0.001c and to alter its vector pretty much at will via the hack drive. One presumes it is spending the energy needed to do this - to cancel out the former vector and impart a new vector. You fire a laser at it; the laser travels at the speed of light of course. How close do you have to be to have a chance to hit it?

Let's imagine that the ship is a bullseye target flying through space. To see it, light must travel from it to you: time T. To hit it, the laser shot must travel from you to it. Between the instant light leaves the target to travel to your eye and the instant when your laser hits the target is 2T. If the target moves far enough during 2T that it is no longer where the laser hits when the laser gets there, you will miss the target. You could lead the target, but you've described a target that could go in any direction with equal ease: knowing which way it is going when you see it does not tell you whether it's still going that way, or went left or right, or backed up, in the time it took for the light from it to reach your eyes. And at 0.001C, the target can move very, very far in 2T: in one second, 300 thousand meters; in one thousandth of a second, 300 meters. So, if the target is 600 meters long and wide and erratically maneuvering at 0.001C, and you train your gun right dead center (because you don't know which way it will go), you need to be within 150 thousand meters - 150 kilometers - to hit it. Beyond that it's the same blind guesswork you'd use if you were throwing a rock at a darting fly.

 

[Adam Dray]

Thanks for the post!

There are a couple of places I can stash extra energy:

• an energy blast in realspace
• in batteries in bubblespace
• in the bubble itself

Absorbing energy (to match the momentum of Mercury, for example) is a different story. The ship can get that energy from:

• its own reactor
• stored energy that it absorbed when it scrubbed energy when it created the bubble
• energy / gravity fields in realspace

These need to make sense in pairs.

For example, I can imagine a ship drawing from gravitic fields around the bubble to pick up momentum, maybe at a rate faster than Mm/d^2, due to some weird quirk of physics we just made up. It could be used as a sort of tractor beam, too.

I can imagine the ship "hovering" in realspace via the bubble, strobing the bubble in some sort of halfway state (?) so that it could pick up momentum while compensating for the lack of enough momentum with its hackdrive. Seems really cheaty.

In other words, it doesn't matter how you bring the ship to 0.001c. What matters is that you show your ship producing enough energy to pay for that privilege.

Well, the ship never, ever moves 0.001c in realspace. The ship is motionless in a bubble that teleports a fraction of a millimeter at a time but never has momentum.

Now I present to you a combat challenge. A ship is able to move at 0.001c and to alter its vector pretty much at will via the hack drive. One presumes it is spending the energy needed to do this - to cancel out the former vector and impart a new vector. You fire a laser at it; the laser travels at the speed of light of course. How close do you have to be to have a chance to hit it?

The vector change is free. The ship has zero mass in real space.

If the bubble is strobing open 100 ms every second for sensors, then any laser pulse that lasts 100 ms has a 10% chance of penetrating the bubble if it even hits the bubble at all.

Hitting the bubble is not hard if the ship maintains its vector. The ship does not get to react to the laser itself, since it will not see it coming.

Hitting the ship if it takes evasive maneuvers is very, very hard. However, the ship could take a perfectly random path, zigzagging to make it very hard to hit. One could create an algorithm to choose how often to zig or zag based on distance to the enemy, since the laser moves at 1 c and the ship moves at 0.001 c. If the distance is 1 light second, then the ship should zigzag so that it's never in the spot where someone would aim 1 second ago. Basically, divide space into a heat map, and predict where the enemy would shoot based on your current vector, and also where the enemy would shoot based on a guess where you might change vector to. Avoid the hottest vectors. Change speed, too.

If the enemy can figure out what algorithm you're using, though, then it can create its own heat map and start guessing where you think you'll go, and shoot there. That increases its chances, but it's still a crapshoot.

 

[Adam Dray]

Really, if I had to take out a ship with a hack drive, I'd create a guided missile with a hack drive, or a guided missile with a hack drive AND lasers.

Get right up on the enemy's ass and light it up. Send three or four of them at a ship and overwhelm its own guns. A few missiles will get taken out, but one of them will hit its target.

Lasers would target the bubble generator, probably, for a chance of disabling the ship for capture rather than destruction. However, if all else fails, the missiles ram and go nuclear.

Missiles with a hack drive would basically be the smallest ship you can stick a hack drive in. They'd be hella expensive, but still cheaper than an enemy ship blowing up your 1000-ton starship, so probably worth it.

 

[Carlobrand]

...Well, the ship never, ever moves 0.001c in realspace. The ship is motionless in a bubble that teleports a fraction of a millimeter at a time but never has momentum. ...

Please be clear as to which model you are using. You presented a momentumless system, and I pointed out that you had a problem when you got close to the Sun. You decided to transmit momentum to the ship to be able to match course once the hackdrive was gone, and I pointed out that you needed to make sure that you were producing enough energy to account for your momentum. Now you're back to a momentumless system, and back to the same problem I first described.

You can use the hackdrive to get from point A to point B, but you either need to transfer momentum to the ship within so it can carry that vector when the hackdrive is off, or you need a normal spacedrive in addition to your hackdrive so you can match speed with other objects in space once you get to point B.

...Hitting the ship if it takes evasive maneuvers is very, very hard. ...

That's the point. It is a combat challenge, not a skeet-shooting challenge. We begin with the assumption that the target is hostile, since you're shooting at it, and that it would prefer not to be shot. I point out that, given the size and circumstance I describe, a certain hit is possible only within 150 kilometers. Double the distance, your odds of a hit drop to about 1 in four. Triple it, one in nine. And so forth. At 1500 kilometers, your chance is 1 in 100. Algorithms imply predictability: your target will do its utmost to be unpredictable. Meanwhile, you are dealing with ships flying 300 kilometers in a second trying to reach targets scattered throughout the system.

Put it this way. Put two long distance runners of equal speed and endurance a hundred yards apart in an open field. Arm them both with handguns. Give them each eyegear that gives them a time-delayed view of the field, the time delay increasing the farther from each other they are. Tell each to kill the other. Put simply, short of complete blind luck or both opponents deciding to close with each other or stand still (i.e. commit suicide), the result will be that neither hurts the other.

Now set a target, and tell one to defend it while the other attacks it. Defender's only choice is to hug the target, moving enough to keep himself hard to hit; venturing out is fruitless. Attacker will see that while defender is hard to hit, the target is not - it is not moving. With a 1 in 100 chance of hitting at 1500 kilometers, attacker can get close enough to rain missiles on the target while the defender's best course is to try to pick off the inbound missiles, 'cause the odds on the attacker are pretty low.

As to antiship missiles, that is up to you. You have to establish that a hackdrive can be built small enough for a practical missile - and faster than the drive of a ship, or it will simply never catch up. You haven't really answered the question of a point defense: the more missiles you need to get through the defense, the greater the cost to disable the target, and at some point you are throwing out more money than your target costs. Whether it is practical or not depends on the rules you make regarding missiles, their cost, and the nature and effectiveness of point defenses - and those rules must have some logic to them.

And, again, is it momentumless or no? If it is momentumless, then the missile only moves when the hack is on. You can't easily drive it into something that way because every time the hack goes off, the missile resumes whatever former vector it had before the hackdrive was turned on. You are constrained to use an approach that takes advantage of the existing momentum. Frankly, the most likely result with the hackdrive flickering the way you describe is that the missile will encounter the opposing hack drive field and either explode uselessly outside the field or be thin-sliced like a salami as it moves past the perimeter of a field flickering 100 ms every second.

 

[McPerth]

Carlo:

See that, once again, all your comments (all of them quite sound, not criticizing them) can also be applied to 2300AD setting and stutterwarp (as Adam already warned us as the closer to his TU, even in the thread's name).

 

[Carlobrand]

Carlo:

See that, once again, all your comments (all of them quite sond, not criticizing them) can also be applied to 2300AD setting and stutterwarp (as Adam already warned us as the closer to his TU, even in the thread's name).

I know not of this stutterwarp of which you speak, having no 2300 AD material, but if it is violating fundamental laws, someone should arrest it. :devil:

 

[Adam Dray]

I know not of this stutterwarp of which you speak, having no 2300 AD material, but if it is violating fundamental laws, someone should arrest it. :devil:

I believe that the MgT core rules also talk about it in the section for alternate ship designs.