Relativity

Joat42 wrote:A couple of points.

o The kinetic energy of a missile is moot if it can't hit the target.
o The faster a missile goes (ie c-fractional), the more difficulty it will have at maneuvering and hitting something - even if that something is an SD.

Only relative velocity matters.

o Nothing really hits the wedge or the sidewall, any object "hitting" them is teared apart due to the gravity shear in the stress band.
o Matter subjected to intense gravitational shearing tend to be converted into radiated energy rather quickly.

Which is what I'm figuring. Look upthread--even if you figure the burst is omnidirectional an MDM plowing into a sidewall releases enough energy to vaporize close to a meter of tungsten armor--and introduce some very nasty shockwaves in whatever is beyond that. Note that being super-tough doesn't help you here, it's purely heat of vaporization that counts.

o Interaction with a wedge or sidewall puts a stress on the generators.
o You could take out parts of a sidewall with enough kinetic force, but see the first point.

I do think it would come down but that wasn't even my objective. Even under worst case assumptions the flash does an awful lot of damage--and I don't think the flash can be omnidirectional given the kinetic energy of the missile.

Jonathan_S wrote:The difference is that the higher your base velocity the less deflection you achieve for the same amount of lateral acceleration. The acceleration produces the same lateral velocity and so the same lateral deflection over any given interval. But that gives a far different "slope" when the base velocity is so much higher.

Exactly. Other than relativity (and it appears that Honorverse drives do not respect relativity) the missile will be just as able to match the jinking of it's target at .7c as at .07c.

(Yes, Honorverse ships respect relativity. There are many things that don't make sense about the drives if they respect it, though--which says to me that the drive is operating in the reference frame of where the wedge interacts with the universe.)

Loren Pechtel wrote:The missile has kinetic energy similar to it's rest mass. That makes collisions the equivalent of low-speed collisions with antimatter, except all the boom is directed inwards.

Actually, at 0.8c, the Lorentz factor reaches 25 = 1 / (1-0.8²). So the relativistic mass of the missile is 25x its rest mass.

But every energy release is equivalent to some antimatter annihilation event with a given amount of antimatter. All you need to do is calculate how much antimatter that would be, if you can find out what the energy release is. The latter is the difficulty: a collision is not equivalent to a conversion of all matter to energy.

My point is: bringing up antimatter here is highly misleading. It could be equivalent to the energy release of a few picograms of antimatter annihilating matter, for all we know.

But these days it doesn't fire every .125s, all of those 16 shots will have been expended before the missiles reached standoff range, there will be none left if a missile doesn't fire at standoff range. Figuring one shot per .125s made sense in the old days where the lasers got multiple shots at each missile, it doesn't apply to MDMs.

If you're thinking about firing against SLN or worse-quality ships, you don't need to ram in the first place. The bomb-pumped grasers will take care of the ship.

If you're thinking about ships that can defend themselves successfully against the missile swarm, like the RHN or Manticore's own ships, then you have to assume that the PDLCs can fire. The PDLC doesn't need to expend all of its shots when the missiles are still too far: good defence software will fire only when it thinks it can hit, so the PDLCs could have plenty of shots left. And 2 seconds "reload" time means the missiles are still a whopping 480,000 km away, which is outside the PDLC basket (about 200 Mm). So if the PDLCs start firing at 200 Mm, the missiles only have 833 ms left before either firing, ramming, or going past the ship. That's less than 7 shots from the PDLC.

And one more thing: a missile can also go past the ship, reorient, and fire backwards.

It could still fire if the solution starts to degrade. However, it's got a booster far superior to the ship, it can match any maneuver other than rolling.

Well, any rotation, not just rolling. The missiles don't need to be coming all in the same plane, so even pitching could make some missiles lose their firing solutions.

The missile's brain needs to decide the moment for best shot. Every microsecond it waits to see if the firing solution will get any better is a microsecond it could get worse or the missile could be intercepted. It's like trying to sell a stock that is going up (or buy one that is going down): how do you know it's hit peak (valley)? I'll grant you that this is actually easier than the stock market, because most of the variables are known to the missiles: with sufficient computing power, they can determine if the PDLCs can still fire or if any CM has a chance of blocking the shot. The problem is that the missiles have about 0.4 seconds to make all of these decisions and there's a lot of imprecision in what the sensors are feeding them.

GA missiles are deadly because they do all of that. Not only the brute force of having a very heavy warhead, but they have sufficient computing power and advanced algorithms to make those decisions on the fly.

I just don't think the algorithms include ramming, at least not for the shipkillers. As mentioned above, against low-quality opponents they don't need it; against high-quality ones they can't afford to try.

ThinksMarkedly wrote:

Loren Pechtel wrote:The missile has kinetic energy similar to it's rest mass. That makes collisions the equivalent of low-speed collisions with antimatter, except all the boom is directed inwards.

Actually, at 0.8c, the Lorentz factor reaches 25 = 1 / (1-0.8²). So the relativistic mass of the missile is 25x its rest mass.

But every energy release is equivalent to some antimatter annihilation event with a given amount of antimatter. All you need to do is calculate how much antimatter that would be, if you can find out what the energy release is. The latter is the difficulty: a collision is not equivalent to a conversion of all matter to energy.

My point is: bringing up antimatter here is highly misleading. It could be equivalent to the energy release of a few picograms of antimatter annihilating matter, for all we know.

But these days it doesn't fire every .125s, all of those 16 shots will have been expended before the missiles reached standoff range, there will be none left if a missile doesn't fire at standoff range. Figuring one shot per .125s made sense in the old days where the lasers got multiple shots at each missile, it doesn't apply to MDMs.

If you're thinking about firing against SLN or worse-quality ships, you don't need to ram in the first place. The bomb-pumped grasers will take care of the ship.

If you're thinking about ships that can defend themselves successfully against the missile swarm, like the RHN or Manticore's own ships, then you have to assume that the PDLCs can fire. The PDLC doesn't need to expend all of its shots when the missiles are still too far: good defence software will fire only when it thinks it can hit, so the PDLCs could have plenty of shots left. And 2 seconds "reload" time means the missiles are still a whopping 480,000 km away, which is outside the PDLC basket (about 200 Mm). So if the PDLCs start firing at 200 Mm, the missiles only have 833 ms left before either firing, ramming, or going past the ship. That's less than 7 shots from the PDLC.

And one more thing: a missile can also go past the ship, reorient, and fire backwards.

It could still fire if the solution starts to degrade. However, it's got a booster far superior to the ship, it can match any maneuver other than rolling.

Well, any rotation, not just rolling. The missiles don't need to be coming all in the same plane, so even pitching could make some missiles lose their firing solutions.

The missile's brain needs to decide the moment for best shot. Every microsecond it waits to see if the firing solution will get any better is a microsecond it could get worse or the missile could be intercepted. It's like trying to sell a stock that is going up (or buy one that is going down): how do you know it's hit peak (valley)? I'll grant you that this is actually easier than the stock market, because most of the variables are known to the missiles: with sufficient computing power, they can determine if the PDLCs can still fire or if any CM has a chance of blocking the shot. The problem is that the missiles have about 0.4 seconds to make all of these decisions and there's a lot of imprecision in what the sensors are feeding them.

GA missiles are deadly because they do all of that. Not only the brute force of having a very heavy warhead, but they have sufficient computing power and advanced algorithms to make those decisions on the fly.

I just don't think the algorithms include ramming, at least not for the shipkillers. As mentioned above, against low-quality opponents they don't need it; against high-quality ones they can't afford to try.

I still think a ram mode should at least be selectable. Absence any evidence to the contrary, ramming should completely destroy an LD.

Aside: With all of the talk of the capabilities of Manty missiles, the electronics must cost a whopping helping of whale oil! I wonder what the cost per Manty missile vs Havenite missile was. The RMN was throwing away a Verge planer's entire GDP with a single demonstration launch. The demonstrations are beginning to look more and more like, "We've got money to burn."

The exchequer must need constant therapy. On that note, who foots the bill of the insanely much costlier electronics at Bolthole?

cthia wrote:Aside: With all of the talk of the capabilities of Manty missiles, the electronics must cost a whopping helping of whale oil! I wonder what the cost per Manty missile vs Havenite missile was. The RMN was throwing away a Verge planer's entire GDP with a single demonstration launch. The demonstrations are beginning to look more and more like, "We've got money to burn."

The exchequer must need constant therapy. On that note, who foots the bill of the insanely much costlier electronics at Bolthole?

Not cheap - the the ludicrous volume of production helps Manticore bring the unit cost down significantly compared to the beginning of the war.

Still by the time and SD(P) has fired off a few full loads of pods the expended ammo probably costs more than the construction costs of the ship. Yet the only thing more expensive that the most capable missiles they can build is having cheaper ones that aren't good enough.

ThinksMarkedly wrote:

Loren Pechtel wrote:The missile has kinetic energy similar to it's rest mass. That makes collisions the equivalent of low-speed collisions with antimatter, except all the boom is directed inwards.

Actually, at 0.8c, the Lorentz factor reaches 25 = 1 / (1-0.8²). So the relativistic mass of the missile is 25x its rest mass.

Check your math.

But every energy release is equivalent to some antimatter annihilation event with a given amount of antimatter. All you need to do is calculate how much antimatter that would be, if you can find out what the energy release is. The latter is the difficulty: a collision is not equivalent to a conversion of all matter to energy.

My point is: bringing up antimatter here is highly misleading. It could be equivalent to the energy release of a few picograms of antimatter annihilating matter, for all we know.

The mass of the debris in question.

But these days it doesn't fire every .125s, all of those 16 shots will have been expended before the missiles reached standoff range, there will be none left if a missile doesn't fire at standoff range. Figuring one shot per .125s made sense in the old days where the lasers got multiple shots at each missile, it doesn't apply to MDMs.

If you're thinking about firing against SLN or worse-quality ships, you don't need to ram in the first place. The bomb-pumped grasers will take care of the ship.

If you're thinking about ships that can defend themselves successfully against the missile swarm, like the RHN or Manticore's own ships, then you have to assume that the PDLCs can fire. The PDLC doesn't need to expend all of its shots when the missiles are still too far: good defence software will fire only when it thinks it can hit, so the PDLCs could have plenty of shots left. And 2 seconds "reload" time means the missiles are still a whopping 480,000 km away, which is outside the PDLC basket (about 200 Mm). So if the PDLCs start firing at 200 Mm, the missiles only have 833 ms left before either firing, ramming, or going past the ship. That's less than 7 shots from the PDLC.

That's not how I understand them to work. It's not that they can only be fired every .125s, but that that's the average firing rate. As the missiles cross the laser basket in less time than the recharge time each laser gets one shot and that's independent of what the others are doing.

And one more thing: a missile can also go past the ship, reorient, and fire backwards.

And very well might do so if that's what it took to get through the wedge. Such a missile obviously wouldn't try to ram.

It could still fire if the solution starts to degrade. However, it's got a booster far superior to the ship, it can match any maneuver other than rolling.

Well, any rotation, not just rolling. The missiles don't need to be coming all in the same plane, so even pitching could make some missiles lose their firing solutions.

If they're from one ship they're in one plane.

The missile's brain needs to decide the moment for best shot. Every microsecond it waits to see if the firing solution will get any better is a microsecond it could get worse or the missile could be intercepted. It's like trying to sell a stock that is going up (or buy one that is going down): how do you know it's hit peak (valley)? I'll grant you that this is actually easier than the stock market, because most of the variables are known to the missiles: with sufficient computing power, they can determine if the PDLCs can still fire or if any CM has a chance of blocking the shot. The problem is that the missiles have about 0.4 seconds to make all of these decisions and there's a lot of imprecision in what the sensors are feeding them.

GA missiles are deadly because they do all of that. Not only the brute force of having a very heavy warhead, but they have sufficient computing power and advanced algorithms to make those decisions on the fly.

I just don't think the algorithms include ramming, at least not for the shipkillers. As mentioned above, against low-quality opponents they don't need it; against high-quality ones they can't afford to try.

I think you're ascribing more to the missiles than they have. I think they simply detonate as instructed. Once again, we have a situation where the technology changed the battlefield and it wasn't noticed--while some missiles need to detonate at max standoff range you'll be more effective if you let a decent number get closer.

They are not independent. The PDLCs have a local mode, but they are part of the squadron or fleet integrated defense network.

ThinksMarkedly wrote:

Loren Pechtel wrote:The missile has kinetic energy similar to it's rest mass. That makes collisions the equivalent of low-speed collisions with antimatter, except all the boom is directed inwards.

Actually, at 0.8c, the Lorentz factor reaches 25 = 1 / (1-0.8²). So the relativistic mass of the missile is 25x its rest mass.

Note only is your math wrong (as stated elsewhere), you don't have the right equation. The Lorentz factor is defined as the reciprocal of the square root of (1-v^2/c^2); e.g. at v = .8c the result is 1.6666667 (.8 squared is .64, 1 less that is .36, square root of that is .6, reciprocal is 1.6666667)

Something to consider is the energy level of the bomb pumped laser beam.
If it is along the same vector as the 0.8 C missile it will be shifted to a higher and more energetic frequency.
Whereas if it is fired backwards, it will be shifted back towards infra red.
A 90 degree sideways one may actually have a slicing component?

cthia wrote:I still think a ram mode should at least be selectable. Absence any evidence to the contrary, ramming should completely destroy an LD.

Sure, the same way our computer operating systems still have code for PS/2 mice, RS232 serial ports, infrared comms and PCMCIA slot cards. The code might be there and the option selectable. I wouldn't trust it without first test.

As for ramming an LD, I don't see why it would be more successful than a graser shot from 25000 km away. Remember an LD has no wedge, so it can be successfully attacked from all angles. There's no wedge or sidewall to obscure the position either; its defence is the sheer amount of CM launchers and PDLCs it can have on its huge hull and its stealth. IF the stealth is defeated somehow, the missiles have the upper hand without the need to ram.