Revising the science of Traveller

[aramis]

One thoguht on the maneuver impacts:

Under TNE, with the limited delta-v, you could infact have "Meeting Engagements"; few ships got non-matchable vectors built up.

Under CT/MT/T4/T20, one can accellerate constantly for long trips, building up vectors which are nigh on non-matchable, and meeting engagements become single pass, unles at one end of a thrust plot or the other, or on parrallel courses.

 

[TheDS]

Hmmm, interesting thought. So, why can't we say there's a maximum allowed velocity? IIRC, FFS describes the operating method of Thruster Plates to be analogous to something grabbing hold of the fabric of reality (those little rings the size of the Planck Length that everything is made of). Well, what's to say that the gears grabbing those rings can only spin so fast before they blow up, or that the maneuver drive cannot be geared (like jet engines and turbines are not geared)?

Please keep in mind these are analogies, I don't really think there's a physical set of gears meshing into the guts of the universe, and I don't recommend you thinking so either.

So what is the limit? Maybe.... 2000 kps? That's about 120 G-hours, which is plenty enough for most insystem destinations. Want to go faster? Get a rocket. 2000 kps is probably just fast enough to get a Bussard ramjet working too. A fairly high limit like this isn't going to make a large difference for transits, but will reduce the obnoxious "jump into the outer system and accelerate ships or rocks to relativistic speed" crap. The biggest problem I see with jump drive is that you can go anywhere at all; there's no reason to go to other star systems if you can reach the whole star system you're in, more cheaply than going elsewhere.

Other than high speed bombing runs, well, it's not a big deal anyway. A fleet that wants to conquer a world will not do many of these, and defensive fleets won't do them at all unless they're scorching their earth.

 

[TheEngineer]

Hmmm, interesting thought. So, why can't we say there's a maximum allowed velocity?

Though it is a compromise I would like that idea, too.
So, a kind of maneuver drive efficiency decrease at higher velocities, caused by relativistic deformations of space/time..

Just like
kps
0 - 100 full g-rating
101-500 0.5 time g-rating
501-1000 0.25 times g-rating
1001-2000 0.1 times g-rating
> 2000 kps - g-rating drops to zero

We just would have to recalc in-system traveltimes...

 

[Malenfant]

Why would you have a "maximum allowed velocity" in space? There's no relativistic effects at a mere 2000 kps.

Obviously you could have a maximum allowed acceleration, because a ship would break apart or people could be squished at accelerations that are too high. But there's no reason to limit the velocity a ship could reach, at least not til you hit a large fraction of lightspeed.

 

[TheEngineer]

Hi !

There are always relativistic effects, just not easily noticable at those velocities...

But as I said, this just would be a compromise in order to delete some weirdnesses (c-rocks) but still allow practical in-system travel.

The thing I would like the most is a thrust - velocity - powerplant output relation with correct energy accounting I mentioned quite a few post before.

 

[TheDS]

Originally posted by Malenfant:
Why would you have a "maximum allowed velocity" in space? There's no relativistic effects at a mere 2000 kps.

Obviously you could have a maximum allowed acceleration, because a ship would break apart or people could be squished at accelerations that are too high. But there's no reason to limit the velocity a ship could reach, at least not til you hit a large fraction of lightspeed.

Dude, reread what I wrote, THEN, get on your 10-speed, put it in first, and pedal for all you're worth. Are you going to get to the point where wind resistance slows you down? Not really. You can think of the wind as your lightspeed barrier if you like. Your maximum speed, though, is limited to how fast you can pedal.

In the above example, when I said to imagine a jet engine, those things are not geared like a car or ten-speed bicycle; you can't get the blades to turn faster for a given engine speed by shifting into a higher gear, and that's pretty much what I was trying to say for the speed limit.

Engineer: interesting table, but as you mentioned, it requires recalculating travel times, and we don't want to add more complexity than is really necessary. I simply propose that a ship behaves as normal until it hits the speed limit, and then you push in the clutch and idle the engine while you drift at 2000 kps. Saves fuel that way, I suppose, if your destination is a billion or so km away. The engine simply cannot "spin" any faster. yes, I know it breaks the analog to a car engine's performance, but that's ok, this isn't a car engine, it's an electronic device.

A further thought: 3000 kps is a better number than 2000, because it is 1% of light, and makes certain calculations easier (plus extends the range before we hit the limit to about 2 billion km, not that I have my calculator handy). That's about 3.5 days speeding up and 3.5 more slowing back down.

 

[TheEngineer]

Hi TheDS !

Engineer: interesting table, but as you mentioned, it requires recalculating travel times, and we don't want to add more complexity than is really necessary

Actually I would just think about changing save jump distance limits.
E.g. in the energy based system it would require about 77 hours for a classical "1g" 1900 ton ships to reach the 100 D limit.
Quite a long time...

So, I would decrease the save jump limit to perhaps 5 D. Here it would still take about 8 hours or so, but the major relations between ships of different performances are maintained and interplanetary travel could move on as normal.

I dont think, that things are more complicate here. Just a bit different.

Well, its an approach to truly revise and not just to tweak.

One of the effects I like most, is that any solar system becomes a more interesting place of adventure, because of the the vastly increased travel times and the need to do in-system jumps on a regular base. So even a charted system may have some secrets or areas "where nobody has gone before".

Just a thought.

 

[TheDS]

77 hours? Maybe you mean planets deep inside a star's gravity well? I don't recall even a size A world requiring more than a few hours to get to 100 D limit, but I've slept since the last time I saw the numbers.

 

[TheEngineer]

Hi TheDS !

It would take that long in a system, there energy is handled more correctly, meaning that speed and distance after a certain time only depends on the amount of energy transfered into the propulsion of the ship.

E.g. assuming a maneuver drive (whatever type) with an input/output (100% efficient) of 100 MW would supply 100000MJ in 1000 seconds.
So these 100000MJ are the amount of kinetic energy available and can be calculated back to an actual velocity.
If a ship wants to leave the gravity field of a planet its has to increase its potentiell energy, too.
Basically its all Ekin+Epot = Eproducedforpropulsion.

Agreed, very conservative, but a bit less handwaving

 

[aramis]

Meeting engagements mean that you have to go from detection to ability to fire for more than a single pass by the time you get in range to fire.

With TNE's limits being on the order of 5-6 G-hours of thrust (typically), you can have engagements at range which are
1) outside the response time of the local authorities
2) predicated upon a high ?v ship being able to detect, intercept, and engage a mush lower ?v ship (even though it might have higher overall thrust ratings)
3) Make fuel hits absolutely lethal. (if you can't RTB, and can't jump, you are effectively dead.)