The ultimate weapon

[mike wightman]

How about being able to plot your position within 5000km anywhere in the galaxy?

http://www.bbc.co.uk/news/science-environment-17557581

Assuming such a galactic gps system is standard by Imperial era CT, possibly with accuracy improvements thanks to TL advances, targeting a well charted planet is going to be trivial.

 

[Hal]

How about being able to plot your position within 5000km anywhere in the galaxy?

http://www.bbc.co.uk/news/science-environment-17557581

Assuming such a galactic gps system is standard by Imperial era CT, possibly with accuracy improvements thanks to TL advances, targeting a well charted planet is going to be trivial.

Ok - now, have the ship pointed in the right direction at hyper-velocities for when the impactor hits its target. As pointed out, the approximate range at which your sensors can point your ship in the CORRECT direction to within 1/360th of a degree of precision, will miss the Earth by 12,000+ km at roughly 18 AU's.

Keep in mind, that 18 AU's worth of travel is about .5% entire journey to reach both the target and impact at .8 C's. So by now, the velocity of the impactor is pretty close to .8C (not quite .8C but nearly there).

So, if the ship is pointed DIRECTLY at Earth at about 18 AU's, and the speed is somewhere in the vicinity of .8c - said ship has a little less than 3 hours to refine its targeting solution, point the ship directly at where the planet will be, and nail it.

Knowing where you are relative to the planet's orbit is fine. Knowing where you are relative to quasars is good as well. Aiming your ship at a given target at high speeds with precision that is better than 1 second of a degree, is perhaps problematical. Think about it. If Laser turrets can't manage that level of precision when firing at targets within 3 light seconds - why would you expect a ship moving at high velocity to do so? The ship has to manuever to adjust its targeting solution the closer it gets to its target. You want to add the complication of needing to dodge incoming defensive fire?

Ok, here's the deal.

Using a vector approach system from Traveller, the ship has a vector of .8C from a distance of 18 AU's. You know where the Planet will be at a given point. Now, use the ship's potential to change its velocity by 6G (or 58.8 meters per second in any given direction) Throw in a dodge versus an ship that is between the Home world, and its defenders with sand casters, missiles, repulsor bays (someone did mention basketball sized projectiles at some point). By now, the defensive targeting solution has firmed up to a near certainty of where that incoming impactor MUST travel through in order to hit the home world within 3 hours.

How much "dodging" around the "line of attack" can the impactor handle and still be able to hit its target at a given point in time? What is 58.8 meters per second relative to the built up velocity of nearly .8C? 6G's is so small relative to the line of attack that the impactor must take, that the defensive solution will be relatively simplified.

Now, can the defenders determine the speed of the impactor? Yes, it is called the Doppler shift in addition to the relatively predictable behavior of the impactor. Will the world have seen the incoming ship during its roughly 47 day journey towards the main world? That I can't say. Do I expect that ships have VERY precise manuevering control and sensors that are very VERY precise? Based on the "to hit" rules for lasers and on missiles - it would seem that a precision of 1/3600th of a degree for aiming purposes is just not the norm for the Traveller Universe. Were it so, then those lasers would have a far better chance of hitting their target at the relatively short range of three light seconds.

 

[rancke]

[Lots of plausible arguments]

I don't have the knowledge to say for certain if the arguments are true, but they certainly sound plausible. In any case they would work as a handwave to explain why ships with magic maneuver drives can't be used to make near-C attacks on worlds. And we all know that there must be some reason why it won't work, because no one in the Traveller Universe worries about it and no one tries to do it.

As an added bit of evidence, we do have one example of a ship being used for a kinetic attack on a world (A Dagger at Efate) and it did not attempt anything like that. That could be handwaved away, sure, but as we don't want to have near-C ship attacks in the TU (well, I certainly don't want them), it's more reasonable to assume that what the Ine Givar tried to do with the Dagger is more or less the most lethality you can get out of using a ship as a kinetic attack weapon.


Hans

 

[BytePro]

...if you abandon Traveller's detection rules ...

CT LBB rules only cover single ship sensors - not planetary, system or other long baseline detection systems. There is really nothing to 'abandon' - though one may choose to add starship sensor rules to other areas.

Like taking the radar range of airplanes as the same limits for satellites - and even astronomy given the relative limits in Traveller.

And we all know that there must be some reason why it won't work, because no one in the Traveller Universe worries about it and no one tries to do it.

Only you and whoever agrees with you.

That no big deal is made about it, doesn't mean or imply its impossible - it only implies that it may be rare. A car, a plane, a mortar, what have you can be dropped on any of us at any time. Sadly, even with all the resources used, analogous intentional acts do happen in real life - some succeed some don't.

Even more directly equivalent - every day we all get bombarded by cosmic rays (can be frac/near-c atoms stripped of electrons) and risk being struck by stray objects - and the only upper limit we suspect for such is near-c.

But such are not usually brought up or a major consideration in the RW.

 

[BytePro]

How about being able to plot your position within 5000km anywhere in the galaxy?

http://www.bbc.co.uk/news/science-environment-17557581

Assuming such a galactic gps system is standard by Imperial era CT, possibly with accuracy improvements thanks to TL advances, targeting a well charted planet is going to be trivial.

Pulsars have been the basis for my Traveller Galactic Navigation System (GNS) since about 1983.

Though, my stated positional accuracy was 100 times better - within 1/2 radius of Size 0 world (50 km, IIRC). Asteroid mining, comet shadowing (for stealth), precision station keeping, docking, targeting, etc. require other methods.

Actually, as is generally the case for popular media - this is quite old news (that keeps getting repeated). In fact, I suspect my 'system' was based on some 1970's or early '80s publication or even earlier SF.

 

[rancke]

And we all know that there must be some reason why it won't work, because no one in the Traveller Universe worries about it and no one tries to do it.

Only you and whoever agrees with you.

Do you have any evidence of anyone in the Traveller Universe making near-C attacks with starships or worrying about such attacks?

That no big deal is made about it, doesn't mean or imply its impossible - it only implies that it may be rare.

It doesn't prove absolutely that it is impossible, but it does imply it.


Hans

 

[BytePro]

Personal assumptions are fine - but that is all they are - such don't speak to my personal assumptions nor 'everyone' else's. Reading just the posts in this thread demonstrates that. If you have some published 'evidence' to the contrary that would apply to the OTU - by all means share it.

As the OP alluded to, the published rules do not address a 'speed limit' - so the idea that high speed, even near-c impactors does not 'exist' is not supported without additional assumptions. And the OTU resides in that framework.

I've given several approaches to making it a non-issue in the OTU or any other TU, without resorting to house rules or additional handwaves - and I'm sure there are plenty more. In-game I've limited things to under 25% c - i.e. about 2 weeks at 6G - but that was totally arbitrary and my players have never tried anything like it. <shrug>

In the RW, near-c jets of parsec scale dimensions have been observed, cosmic rays are a reality, and there is no reason, yet, to completely rule out such in a fictional setting with drives that are not otherwise limited. Even if M-Drvies were explicitly limited, that would not necessarily prevent other forms of propulsion that weren't limited.

 

[mike wightman]

And as I posted earlier - near c travel is canonical within the OTU.

Imperium, Dark Nebula, TCS, and Hinterlands.

 

[rancke]

Personal assumptions are fine - but that is all they are - such don't speak to my personal assumptions nor 'everyone' else's. Reading just the posts in this thread demonstrates that.

By the same token your assumptions are no better. You're assuming that the game rules for thruster drives are complete and accurate even when taken beyond the context in which they typically apply. Which is, as someone pointed out earlier, that you can accelerate at 6G for 3½ days after which you typically star decelerating at the same rate. If you need to go any farther, you typically jump.

Game rules that ignore boundary conditions are quite common.

If you have some published 'evidence' to the contrary that would apply to the OTU - by all means share it.

See previous posts.

As the OP alluded to, the published rules do not address a 'speed limit' - so the idea that high speed, even near-c impactors does not 'exist' is not supported without additional assumptions. And the OTU resides in that framework.

The thing is, two mutually exclusive assumptions may be equally valid, but they can't both be true for the same universe. So in the case of the OTU you can either assume that such destructive use of thruster drives is possible but everybody (up to and including rabid fanatics of all stripes) are nice enough not to use it (until the PCs come along), or you can assume that it is not possible.

In the RW, near-c jets of parsec scale dimensions have been observed, cosmic rays are a reality, and there is no reason, yet, to completely rule out such in a fictional setting with drives that are not otherwise limited. Even if M-Drvies were explicitly limited, that would not necessarily prevent other forms of propulsion that weren't limited.

Other forms of propulasion are limited by physics. In reality it would take a tremendous anmount of energy to accelerate a body to near-C velocity and there are no known real drives that are capable of doing so. It is the "fact" that maneuver drives violate physical laws as we know them that makes the proposed abuse of the rules conceivable.


Hans

 

[rancke]

And as I posted earlier - near c travel is canonical within the OTU.

But use of near-C travel as a weapon is not.


Hans

 

[aramis]

And as I posted earlier - near c travel is canonical within the OTU.

Imperium, Dark Nebula, TCS, and Hinterlands.

And, per T4, nearly impossible to achieve with Thruster Plate M-Drives.

Per T4, your maximum speed is based upon 2000 diameters of the local star... for earth, with Sol being 1392000 km across, that's 2748000000km, which at 6G gets you about 6.1PSL, and at 1G gets you about 2.5PSL. Oh, and this ignores that you can't quite get that distance exact, (but can bend around the primary for slightly more distance and speed, but not a whole lot.

So there's a serious disconnect.

 

[Dragoner]

The magnetosphere can dissipate a certain amount of plasma from a vaporized object. For every measure, there is often a counter measure.

 

[mike wightman]

And, per T4, nearly impossible to achieve with Thruster Plate M-Drives.

Per T4, your maximum speed is based upon 2000 diameters of the local star... for earth, with Sol being 1392000 km across, that's 2748000000km, which at 6G gets you about 6.1PSL, and at 1G gets you about 2.5PSL. Oh, and this ignores that you can't quite get that distance exact, (but can bend around the primary for slightly more distance and speed, but not a whole lot.

So there's a serious disconnect.

You don't think for one moment that the numptys that came up with the gravity field strength dependence of thruster plate and grav drives actually thought about their implications?

Or did any of the math?

 

[mike wightman]

But use of near-C travel as a weapon is not.


Hans

Cough - Ancients - cough.

 

[BytePro]

The magnetosphere can dissipate a certain amount of plasma from a vaporized object. For every measure, there is often a counter measure.

Indeed. (To both!)

As mentioned upthread - a system's magnetic field protects the system from galactic cosmic rays - perhaps as high as 90% of them (IIRC) - so velocity ramp ups that exceed such protection expose a ship to a much higher risk of sensitive equipment failures. Of course, the counter measure could be a very intense magnetic 'shield'.

Natural processes manage to accelerate particles to near c (over 99% c have been measured) - so we know it can be done. Of course, generally, protons and atomic nuclei (all stripped of electrons), though all manner of subatomic particles are found - but not molecules and macroscopic chunks of matter. Blazers spew massive gas jets to be sure, but I don't believe we've any evidence of say a star moving at near-c.

In the OTU, unless someone is planning to make a world uninhabitable while wiping out large populations, frac/near-c impactors would be major overkill - and perhaps more prone to failure than simply thrusting in from orbit (despite the effort required for 'sneaking' in/'surviving' to objective).

You don't think for one moment that the numptys that came up with the gravity field strength dependence of thruster plate and grav drives actually thought about their implications?

Or did any of the math?

Yeah - they didn't have Google calculator!

I tend to do most math in my head - but have to double check with a calculator nowadays. Accidentally 'discovered' Google calculator today -
in the search field you can enter things like: (2.9 days * 60 m/s^2) / c = and Google will reply with a solution: ((2.9 days) * 60 (m / (s^2))) / c = 0.0501466918

(This is great - now I can screw up faster! )

 

[rancke]

Cough - Ancients - cough.

Who says those asteroids were accelerated to any significant degree? Kinetic kill missiles are mentioned several times in canon; near-C kinetic kill missiles are not.

One of the features of near-C attacks is the lack of time for the defenders to avert the attack. If you just point a ship at a world and accelerate, nearby PC-owned ships have a good chance of stepping in (as A Dagger at Efate demonstrates) and decent orbital defense can shoot the stuffing out of approaching ships (Which, incidentally, is a problem with ADaE -- where are the defenses a pop 9 world would have? (Not to mention the fleet stationed at the naval base)).


Hans

 

[mike wightman]

Canon allows for near c travel. The physics of the setting allows it.

Someone, somewhere, sometime is going to decide to try it.

So why has it not been mentioned?

Why has it not happened up to now (whenever now is - 1107 ok for you)?

Treaties between the major powers would either outlaw near c weapons or at least ensure a MAD doctrine (why were chemical weapons not used during WW2 in Europe or Russia - they were used in China).

What stops a terrorist?

Has the Imperium covered up near c strikes?

 

[mike wightman]

Who says those asteroids were accelerated to any significant degree? Kinetic kill missiles are mentioned several times in canon; near-C kinetic kill missiles are not.

One of the features of near-C attacks is the lack of time for the defenders to avert the attack. If you just point a ship at a world and accelerate, nearby PC-owned ships have a good chance of stepping in (as A Dagger at Efate demonstrates) and decent orbital defense can shoot the stuffing out of approaching ships (Which, incidentally, is a problem with ADaE -- where are the defenses a pop 9 world would have? (Not to mention the fleet stationed at the naval base)).


Hans

Secret of the Ancients explains how the ancients did it using portal technology.

 

[rancke]

Canon allows for near c travel.

I believe that has been established.

The physics of the setting allows it.

But that one hasn't.

Someone, somewhere, sometime is going to decide to try it.

I agree completely. If it was possible, someone would have tried it.

So why has it not been mentioned?

Why has it not happened up to now (whenever now is - 1107 ok for you)?

It is always arguable that no one has gotten around to mentioning it. As I said earlier, absence of evidence is not PROOF of absence.

But another possibility is that it doesn't work.


Hans

 

[rancke]

Secret of the Ancients explains how the ancients did it using portal technology.

So anything they did is useless as evidence for near-C attacks without access to portal technology? I have no problem with that.


Hans