Pearl Harbour 5642....

[The Oz]

...having taken some time to think about this....

I agree that I made a mistake with how large the volume that the target ship could actually be in =at the time of the weapon arriving=. I do kinda wish you'd not used the term "gross conceptual error" as it brings back bad memories to this former Navy nuke.

But I'm not sure I understand you about the velocity of the target ship distorting the shape of the volume the target ship can occupy at the time of the weapon arriving.

To use a simple example, I'm thinking of a ship moving at 1000 meters/second, with a maximum change in potential position of 100 meters in the time available (2 seconds, as we were talking about before). If the target just coasts, it'll be 2000 meters further along the vector the enemy last knew about. If the target chooses to continue to accelerate along its established vector, it'll be 100 meters further along, or 2100 meters from where the enemy last knew it to be. If the target decelerates, it'll be 100 meters short of the possible future position, or 1900 meters along it's last known vector. If the ship accelerates at 90 degrees to its vector, it'll be 100 meters off to the side (top, bottom) from it's projected position. This (to my imagination) produces a 100 meter radius sphere where the ship could be in 2 seconds, the sphere centered around the ship's predicted position without any change in its original vector.

I don't see how the magnitude of the ship's original vector can change the shape of the ship's possible position zone. The magnitude of the original vector can and does change just where that PPZ will be (in a predictable fashion) but the shape is still a sphere.

Please understand that I am not criticizing or disagreeing, I just don't see how things work the way you say they do. I am using just simple "tip-to-tail" vector addition instead of calculus (I don't feel like brushing off my calculus just now) but I don't think that would affect things this much.

One thing else in this is that even a 6-G ship can't change its vector that much in only 2 seconds, which leads me to wonder about just how big TRAVELLER warships tend to be and how much of that PPZ the ship might still occupy and just how big the zone of effect might be for a spinal mount meson gun? We know the potential change in position is small, and if the ships are big and the weapon bursts are big it might be very hard to generate a miss just from evasive action. (I have always imagined bursts from meson guns as being essentially linear as the mesons decay at slightly different times, with a big burst in the middle of the line where most of them decay.) Which would put the whole idea of Agility into question and make electronic warfare capabilities much more important as the way to get the enemy to miss.

 

[Whipsnade]

The Oz wrote:

"I agree that I made a mistake with how large the volume that the target ship could actually be in =at the time of the weapon arriving=. I do kinda wish you'd not used the term "gross conceptual error" as it brings back bad memories to this former Navy nuke."


Mr. Oz,

Mea culpa. Class 8202, Section 9, NNPS Orlando here.

"But I'm not sure I understand you about the velocity of the target ship distorting the shape of the volume the target ship can occupy at the time of the weapon arriving."

Oh, that. It's because the range doesn't stay constant in distance OR time! The target is always either opening or closing the range thus adding various nasty bits to the "If my weapon arrives in precisely X seconds, what are all the possible target positions be at that exact exact moment?" question. The velocity of the target will effect the range of engagement so that velocity will thus effect the 'shape' of the volume of possible target locations. At low velocities, the effect is minimal to point of inconsequence. At high velocities, the effect becomes much more pronounced and must become part of the targeting function.

Check out C.J. Cherryh's Merchanter universe for ideas on how high velocities screw with things, especially "Heavy Times" and it's sequel. In those books, the Sol Company Fleet is being built, the crews selected, and various operational techniques tested. It's rather eye-opening.

"One thing else in this is that even a 6-G ship can't change its vector that much in only 2 seconds, which leads me to wonder about just how big TRAVELLER warships tend to be and how much of that PPZ the ship might still occupy and just how big the zone of effect might be for a spinal mount meson gun?"

There's been quite a lot of work done it calculating 'auto-hit' distances for Traveller ship combat and other games. The TML and 'sfconsim-1' archives are well worth perusing.

"(I have always imagined bursts from meson guns as being essentially linear as the mesons decay at slightly different times, with a big burst in the middle of the line where most of them decay.)"

Yup, me too. Taking meson guns as described in canon (for they cannot be described in RL terms), the area of their effect should be a 3D bell curve of sorts. MGs supposedly accelerate shortlived particles to relativistic speeds, thus delaying their violent decay. The speed of the particles is minutely adjusted so that their decay occurs after a specific period of time has elapsed. Naturally, this period of delay is (hopefully) a function of the range to the target. Some particles will be relatively faster and some particles will be relatively slower, so a certain percentage of them will decay sooner/closer to the MG and later/further from the MG. Taking the entire volume of space that the particles decay in and measuring the energy released will give you the 3D bell curve you spoke of.

"Which would put the whole idea of Agility into question and make electronic warfare capabilities much more important as the way to get the enemy to miss."

IMEHO, agility has never been adequately explained. Also, EW has all but been ignored. Without 'magic' directional heat radiators, OTU vessels will easily appear on sensors. However, knowing that a vessel is out there and knowing enough to get a weapon strike on it are two very different things!

Finally, let me trumpet a nifty set of minis rules for Traveller that I believe you will enjoy. They're called 'Power Projection: Escort' and are an adaption of 'Full Thrust' to the OTU. I have them, play them, and enjoy them very much. You can purchase them at the BITS website.


Sincerely,
Larsen

 

[TKalbfus]

Not that dramatic; this is TRAVELLER, not STAR WARS. I've played both and I know the differences. As a game designer, I don't like creating situations where one side can act with good effect and the other has no effective power of reply. I like to create things so that if you want more effect, you have to accept some risk, and the more effect you want, the more risk you have to accept.

What does whether spaceships fly like airplanes or not have to do with drama? The only reason Star Wars ships fly like airplanes is because most movie watchers have flown in airplanes and they haven't flown in spaceship. The average viewer being targeted was probably asleep in his physics class during the discussion on Newtonian motion, he probably remembered enough to get a C on his final examination and then forgot the whole thing when he no longer needed it.
SW spaceships bank when they turn because that is what such a viewer expects. Such a person gets upset if he sees a spaceship flying backwards when it is slowing down and "Hey what happened to the Sound! There are all these explosions going on and I can't hear a thing. The side views of the spaceship don't show any relative motion and all I see are flashes and silent explosions. What kind of movie is this? Also the enemy ships don't come close enough to those of the heroes to be seen, I don't even know what they look like. All they do is fire things that cause explosions."

In this particular situation (the raid on an "anchored" fleet) the no-risk option is to do what DS has suggested: send in a swarm of missiles. Your raiders have practically no risk, but your effect will be limited as you can't be sure what (if anything) you will hit.

My "high-speed pass" is the next up in risk/reward: you get to use precisely targeted energy weapons (especially spinal mounts) and missile salvos, but you'll only get one or two shots (thanks to your high velocity), the enemy will get to reply, but not much as he is hopefully taken by surprise and only his ready-alert forces can shoot back.

A high speed pass is a high speed pass for both sides, all motion is relative. You get one shot for each crewed and mounted weapon system that you can bring to bear for a single action and it is hit or miss with no second volleys, but the same can be said for the enemy vessels who may out number you, the advantage is aways with the ships that have the most weapon systems to bring to bear. The larger ships can also detect you further out, they can begin firing at you earlier. In space you cannot come in under their radar, if the fleet is not on the surface of a planet.

 

[The Oz]

Originally posted by Larsen E. Whipsnade:
Mea culpa. Class 8202, Section 9, NNPS Orlando here.

I was a year behind you: class of 8303. I did more gaming (TRAVELLER and the original STAR TREK RPG, and SFB) at NNPS than I did anywhere else in the Navy.

Check out C.J. Cherryh's Merchanter universe for ideas on how high velocities screw with things, especially "Heavy Times" and it's sequel. In those books, the Sol Company Fleet is being built, the crews selected, and various operational techniques tested. It's rather eye-opening.

I've not read those book of CJ's, I'll have to check them out. I am very fond of Downbelow Station and the Chanur series.

IMEHO, agility has never been adequately explained. Also, EW has all but been ignored. Without 'magic' directional heat radiators, OTU vessels will easily appear on sensors. However, knowing that a vessel is out there and knowing enough to get a weapon strike on it are two very different things!

Finally, let me trumpet a nifty set of minis rules for Traveller that I believe you will enjoy. They're called 'Power Projection: Escort' and are an adaption of 'Full Thrust' to the OTU. I have them, play them, and enjoy them very much. You can purchase them at the BITS website.

I've heard about Power Projection and will get it when I have the extra cash on hand.

 

[Whipsnade]

Tom Kalbfus wrote:

"What does whether spaceships fly like airplanes or not have to do with drama?"


Mr. Kalbfus,

You are a treasure! You ask 'why is it more dramatic?' and then answer your own question in the sentences you typed afterwards!

"... because most movie watchers have flown in airplanes and they haven't flown in spaceship."

"SW spaceships bank when they turn because that is what such a viewer expects."

"Such a person gets upset if he sees a spaceship flying backwards when it is slowing down ..."

"There are all these explosions going on and I can't hear a thing."

"Also the enemy ships don't come close enough to those of the heroes to be seen, I don't even know what they look like."

It's more dramatic because it is more understandable to more people.


Sincerely,
Larsen

 

[Rupert Boleyn]

Originally posted by Larsen E. Whipsnade:


The Oz:
"(I have always imagined bursts from meson guns as being essentially linear as the mesons decay at slightly different times, with a big burst in the middle of the line where most of them decay.)"

Larsen E. Whipsnade:
Yup, me too. Taking meson guns as described in canon (for they cannot be described in RL terms), the area of their effect should be a 3D bell curve of sorts. MGs supposedly accelerate shortlived particles to relativistic speeds, thus delaying their violent decay. The speed of the particles is minutely adjusted so that their decay occurs after a specific period of time has elapsed. Naturally, this period of delay is (hopefully) a function of the range to the target. Some particles will be relatively faster and some particles will be relatively slower, so a certain percentage of them will decay sooner/closer to the MG and later/further from the MG. Taking the entire volume of space that the particles decay in and measuring the energy released will give you the 3D bell curve you spoke of.

I've always maintained that this must be how a Meson Gun's burst looks, too. IMTU a Meson Gun's burst has a shape that depends on power, TL, and manufacturer, so they can be identified by their 'burst signature'. Once that's done you can start locating its by calculating how far away it had to have been, which direction the long axis was in, and so on.

The Oz:
"Which would put the whole idea of Agility into question and make electronic warfare capabilities much more important as the way to get the enemy to miss."

Larsen E. Whipsnade:
IMEHO, agility has never been adequately explained. Also, EW has all but been ignored. Without 'magic' directional heat radiators, OTU vessels will easily appear on sensors. However, knowing that a vessel is out there and knowing enough to get a weapon strike on it are two very different things!

In HG2 Agility was simply the Gs of acceleration you had left after powering everything else, and was therefore a measure of your ability to evade in unpredictable ways. I've always assumed that HG's use of computer sizes in firing and defence was a measure of EW and of your ability to predict the target's evasive manoeuvres (or avoid prediction of same). OTOH MT's and T20's version of agility, which rely on power left after powering everything including manoeuvre drives, has never been explained to my satisfaction.

TNE/Brilliant Lances had rules for EW that seemed adequate to me. Stealth and masking made it harder for the enemy to get a firing solution on you, as did evasion, decoys and jammers. Area Jammers made it hard for them to get a lock on everything in the area except the jammer.

 

[Typhonis]

hmm Battlestar Glactica started with a Pearl Harbour style attack