"Meson" Guns???

[Malenfant]

Just something to keep in mind at high TLs - please make it consistent!

Also, this may be worrying about things that are far beyond what you were thinking of, but I hear a lot of Ancient handwaves that just assume that Ancients could do whatever they liked - particularly when it comes to terraforming or moving planets or stars, etc. They still have to overcome whatever problem they're facing by applying technology to it though - for example, to move a planet means you either somehow have to be able to totally change its momentum vector or negate its mass, or just plop it through a wormhole that is wide enough to accommodate it (or even just teleport it) - all of which requires a vast amount of energy that has to be imparted to the planet or system moving it, without destroying it.

So while the adage may say that "any sufficiently advanced technology will seem like magic" to a lower tech civilisation, bear in mind that the operative phrase is highlighted in bold - it's NOT magic, it's just so advanced that it looks like it is. But even with the Ancients, or even TL 15-20, I don't think that's so advanced that we don't have a clue about the principle it operate under.

So for me at any rate, it's not enough to say "OK, the Ancients moved the planet to 3 AU further out using their Unspecified Ultratech Armwave Device". They still have to have the means to move the planet somehow, based on everything that's been specified before. If they have planetary-scale teleportation or wormholes (I think that matter transference does show up at high TLs doesn't it?), then fair enough. But if not, and they don't have the obvious means to do it without destroying the planet in the process, then that means that they still can't do it. That's how I'd approach it anyway - YMMV

.

 

[Lexx]

In one of his best novels, "A world out of time", larry niven had to deal with moving earth, and came up with a plausible way to do it.

While I don't recommend most niven works, esp his later novels which mostly became pro fascist statements, A world out of time was one of hie early ones before he became a fascist and in fact featured an anti-fascist main character.

So if you want to read a plausible account on movien an earth type planet read a world out of time.

 

[mike wightman]

Don't worry Malenfant, all the Ancient technology is TL25+, well beyond Extreme Stellar

 

[Malenfant]

Does that mean it's Ridiculously Extreme Stellar?

 

[mike wightman]

 

[SanDragon]

Maybe it's Ludicrously Stellar and it comes in plaid.

 

[Malenfant]

Heh. Funnily enough, I was thinking about that as well when I was writing my post .

 

[aramis]

Originally posted by Sigg Oddra:
Don't worry Malenfant, all the Ancient technology is TL25+, well beyond Extreme Stellar

Uhm, guys, the MT tech tables show all the goodies the anchients have in Adv12 at TL 20-21... including starship jump gates.... (ref's Companion).

 

[mike wightman]

Those aren't starship jump gates, they are starship sized pocket universe portal entrances .
The PC's starship has to use its own jump drive once inside the pocket universe in order to travel from system to system IIRC.
The Ancient portal system only has a range of 72 light minutes, you'd need an awful lot of those to travel interstellar distances.

I think the TL21 Starship sized jump portals are more likely to be the planet based jump portals from The T4 adventures.

And the cap for extreme stellar is TL20

 

[Psion]

Gah! I always preferred that Traveller tried to extrapolate instead of handwave. In fact, thruster plates rubbed me the wrong way until I read "Indistinguishable from Magic" by Robert Forward, which proposes a plausible if unlikely method of explaining reactionless drives.

I might as well explain this, as it could figure into my explanation of what a meson gun really is, below. The basic problem with reactionless drives is that it violates conservation of momentum. To go forward, you must push something backwards.

Forward's speculation is that, basically, conservation of momentum is only true most of the time, just like convervation of mass is only true most of the time (because mass can be converted to energy, thus allowing fun things like fusion.) So he speculates that maybe linear momentum is one of these quantities that can be converted to something else. Picking the right cosmological constants, if some reaction could convert angular to linear momentum, the angular momentum stored in subatomic particles could be the source of almost free momentum.

I don't like the idea that they are some sort of jumpspace bubbles. That's star trek style technobabble.

In TA7, the relevant paragraph is:

Meson Guns are an advanced form of particle
accelerator, which accelerates the particles to relativistic speeds. The weapon is designed so that the particles pass through intervening matter (due to their high speed) and decay within the target, causing internal explosions and radiation
damage. In fact, the particles used are not mesons (which cannot function in this way),

Okay, established: it is some sort of particle accelerator. I am curious why the authors think it can't work that way. Positive and negative mesons would have the same problem electrons and protons have: they would interact with any matter they come in contact with and be stopped by any armor. But there are, IIRC, neutral mesons. I know from my work in the nuclear field that neutrons, also neutral particles, travel easily through most matter if they have a high energy (water slows neutrons down, but there is no material that would have similar properties to mesons.) So I am not seeing why, if you accelerated neutral mesons to this speed, they wouldn't work.

Now there are two possible reasons assuming the authors did their research why they might be saying this.

First, the life of a particle is essentially random. The halflife is merely a time in which half of the mesons (or whatever) decay. Though relativistic speeds let us influence the half-life, it can't make all mesons decay on a dime. I'm figuring perhaps there is some principle behind this randomness that we can exploit to precondition the mesons that we actually pick out of a pile and toss at an enemy to be ones that have a somewhat predictable decay. (I still picture the process as being somewhat imprecise, and picture a meson gun strike as having an oblong nimbus that sticks out either side of the ship, as some particles decay too soon or too late...)

Second, perhaps they were confronted with the problem that you need a charge on a particle to accelerate it in a particle accelerator. There are two possible ways around this.

One, perhaps the meson gun creates the mesons in a way that already has them heading in the needed direction when they are created.

Two, perhaps we use the above thruster plate principle, and use they "thruster plate" reaction to convert the meson's spin into linear momentum instead of using an electrostatic accelerator.

Or, finally, perhaps it is, like TA7 says, other particles. There are some particles larger than protons called hyperons that decay very quickly (though I don't know if any are neutral.)

That's my two cents worth of slightly less infeasable technobabble.

Edit: As a side note, I seem to recall that The Traveller Adventure had an exhibit that talked about "how meson guns work." Anyone have that handy? I may have to look that up when I get home.

Edit: Nope. TTA has an exhibit with a pretty picture, but doesn't go into detail about how it operates.

 

[aramis]

TA 7 is trying to correct a prior article which claimed Pi Mesons were used. It is not consistant with prior canon.

Mesons of the type used in Traveller don't have to "Get In", they have a half life measured in fractions of a second. If you can group them well enough at creation, and accellerate them accurately enough, you can put the bulk on a designated target.

Now truth be told, there isn't a known real particle which is weakly interacting until decay, but several theoretical predictions say there will be some.

Now, the nimbus is liekly to be a linear feature, providing a line to the launcher.

 

[far-trader]

My biggest problem still lies in targeting. Sure you can go with the saturation model I like for beam weapons and explaining space combat turns being so long but the "Meson" gun will have to saturate a volume rather than just sweep through a cone. That should either take a lot longer or use a lot more energy for the higher rate of fire, well imo anyway.

Hmm, maybe the energy levels are about right looking at it again in T20. At least for the bay meson guns vs bay particle accelerators. I'm not so sure the spinal versions are as well balanced at a glance.

Still, I'm not sure my suspenders go high enough to believe you can target to a couple of meters accuracy, at 10's of thousands of kilometers, to the instant, for a target capable of changing its vector by up to 6G.

I do like the idea of a sloppier nimbus version, producing more of a field effect of which some is going to be inside the ship and do damage and the rest is harmlessly dissipated into space. Something along those lines might fit my oddly limited capacity for belief in this matter

 

[Psion]

Originally posted by Aramis:
Now truth be told, there isn't a known real particle which is weakly interacting until decay, but several theoretical predictions say there will be some.

How weakly interacting does it need to be? As mentioned earleir, high energy neutrons will slide right through several feet of metal with minimal loss of flux just because that's how open the crystal lattice is from the viewpoint of a neutral particle. They are only slowed down by water because maximum energy transfer away from the neutrons occur when they collide with hydrogen nuclei -- which slows them down enough that they are more readily absorbed. Wouldn't neutral mesons exhibit the same characteristics. (Genuinely curious -- my specialty is nuclear physics, not particle physics.)

 

[Psion]

Originally posted by far-trader:
My biggest problem still lies in targeting. Sure you can go with the saturation model I like for beam weapons and explaining space combat turns being so long but the "Meson" gun will have to saturate a volume rather than just sweep through a cone. That should either take a lot longer or use a lot more energy for the higher rate of fire, well imo anyway.

What could be going on here is some sort of feedback loop. Perhaps meson guns do a very low energy "pre-fire" and looks for the radiation signature where the mesons are decaying, and compensates until it is on top of the target and then "cranks it up" to damaging levels.

 

[aramis]

Actually, at ranges of greater than 30Mm (30K KM), you have to account for volume satraion even with lasers.

Not NEARLY so welll, but you still do. Y'see, time on target is 2x range in LS for Lasers. Somewhat longer than that for PBeams. Considerably longer for Fusion and Plasma. Assuming a 1/10th second pulse, that means you have to inntercept with a laser, the actual position of the target with a salvo that has an effective length of 30Mm, based upon 1/10th second old data, 1/10th second in advance (all times per 30Mm hex).

PBeams are probably similar lengths

Fusion and Plasma fire is probably 2-3 KM long bolts...

And, courtesy of advanced multi-input sensor kits, which can be fairly safely assumed, range to the LKP (which is always different that actual range to target and range to fire solution point) is fairly easily detected. For Active sensors, pulse return time determines distance, as well as confirms with stereo image of the returns.; passives use stereo immaging.

 

[starwaster2]

Area saturation is a better solution. The problem with the method you propose: Let's say my target is 5 light seconds out. By the time the 'damaging' packet of mesons arrive at the target destination, those coordinates are 10 seconds out of date. (actually somewhat more than that as the beam isn't travelling at light speed)

And the target would detect the radiation before I do and take immediate evasive action.

Originally posted by Psion:
</font><blockquote>quote:</font><hr />Originally posted by far-trader:
My biggest problem still lies in targeting. Sure you can go with the saturation model I like for beam weapons and explaining space combat turns being so long but the "Meson" gun will have to saturate a volume rather than just sweep through a cone. That should either take a lot longer or use a lot more energy for the higher rate of fire, well imo anyway.

What could be going on here is some sort of feedback loop. Perhaps meson guns do a very low energy "pre-fire" and looks for the radiation signature where the mesons are decaying, and compensates until it is on top of the target and then "cranks it up" to damaging levels. </font>[/QUOTE]

 

[Psion]

Okay, it's been a while since I crawled into high guards, but is combat scale out to 5 light seconds?

Anyways, as for detecting and taking evasive action: why of course. It's all about tactics and counter-tactics. That's what makes the game fun!

 

[mike wightman]

The only real world scale for HG combat comes from the conversion notes in Mayday.
Inside 5 ls is short range,
between 5 ls and 15 ls are at long range,
beyond 15 ls is out of range.

 

[Straybow]

With c-limited physics and multi-gee maneuvering you aren't going to hit squat at 5 ls. You'd be lucky to hit a ship with a beam weapon at ½ ls.

 

[Psion]

Originally posted by Sigg Oddra:
The only real world scale for HG combat comes from the conversion notes in Mayday.
Inside 5 ls is short range,
between 5 ls and 15 ls are at long range,
beyond 15 ls is out of range.

That, frankly, sounds ridiculous. That's Star Trek scale stuff, not traveller, AFAIAC.

I thought MT had an explicit distances assigned to range bands. (No book here ATM, but if someone wants to confirm or deny), which I though was in terms of hundred or thousands of KM, not "light seconds."